JP4605526B2 - LED lamp - Google Patents

Description

  The present invention relates to an LED lamp including a vehicular lamp such as a headlamp using an LED element as a light source.

Conventionally, an LED headlamp using an LED element as a light source is configured, for example, as shown in FIG.
That is, in FIG. 5, an LED headlamp 1 includes a resin housing 2 having an open front surface, and a plurality (two in the illustrated example) of LED lamp units 3 provided in the housing 2. And a front lens 4 made of a translucent resin material attached to the housing 2 so as to cover the front surface of the housing 2.

Each of the LED lamp units 3 includes at least one LED element, and is supported inside the housing 2 by a lamp unit support 5 so as to emit light forward.
Here, as is well known, each LED lamp unit 3 includes an LED element 3a, a reflector 3b, a projection lens 3c, and a shutter 3d, and focuses the light emitted from the LED element 3a by the reflector 3b. The projection lens 3c irradiates forward, and the shutter 3d forms a cut-off line.

  According to the LED headlamp 1 having such a configuration, the LED elements of each LED lamp unit 3 are driven to emit light by supplying power to each LED lamp unit 3 from the outside. Then, the light emitted from each LED lamp unit 3 is irradiated forward through the front lens 4.

In such an LED headlamp 1, heat is generated as the individual LED elements emit light.
By the way, as shown in FIG. 6, it is known that the LED element generally has a negative light emission characteristic with respect to temperature, that is, the light emission efficiency (light flux) decreases as the temperature increases.
Therefore, in the LED headlamp, since the housing 2 and the front lens 4 are made of resin with low thermal conductivity, it is important to take measures against heat generation of each LED element, and in particular, keep each LED element at the same temperature. It is required to do.

On the other hand, in Patent Document 1, a space is provided in the thick portion of the convex lens for condensing light, a tubular member for supplying and discharging a transparent liquid is provided in the space, and a tubular member is provided in the space of the convex lens. There is disclosed an LED headlamp having a cooling means for cooling the convex lens by supplying and discharging a transparent liquid as a refrigerant through a member.
Patent Document 2 discloses an LED illumination unit including a cooling device for cooling a semiconductor light emitting element.
JP 2004-214144 A JP 2005-071870 A

  By the way, in the LED headlamp by patent document 1 mentioned above, it is comprised so that the heat which generate | occur | produces in each LED may be cooled indirectly by cooling a convex lens, The cooling effect is comparatively low, Cannot be cooled sufficiently, and is not particularly configured to cool each LED to the same temperature. For this reason, for example, since the cooling effect of the LED arranged near the center is lower than the cooling effect of the LED arranged near the periphery, the temperature of each LED varies.

  Moreover, in the LED type illumination unit by patent document 2 mentioned above, there is only description that it is provided with an air-cooling or water-cooling type cooling device, and it does not describe what is specifically cooled and how.

  In the present invention, even when a plurality of LED lamp units are included, the LED lamp units can be reliably cooled by a simple configuration, and preferably each LED lamp unit can be kept at a uniform temperature. An object of the present invention is to provide an LED lamp.

According to the first configuration of the present invention, the above object is achieved by a housing that is open at the front, and at least one LED element that is disposed so as to be vertically shifted so as to irradiate light forward in the housing. Each of the LED lamp units is thermally connected to each other, and a front lens made of a light-transmitting material that closes an open front surface of the housing. A plurality of cooling units, a heat dissipating unit disposed outside the casing and releasing heat to the outside, and a flow path of a water-cooled cooling pipe that transmits heat of each cooling unit to the heat dissipating unit. If has a water-cooled cooling system Ru provided with an inner diameter of the flow path of the cooling tube, it is at least one of shape and length, power of each LED lamp unit each cooling unit is connected Compatible with Characterized in that it is set so that the flow rate was, is achieved by the LED lamp.

Further, according to the second configuration of the present invention, the object described above is the case where the front is open, and at least one each of which is arranged so as to be shifted up and down so as to irradiate light forward in the case. An LED lamp for a vehicle that includes a plurality of LED lamp units each having an LED element and a front lens made of a light-transmitting material that closes an open front surface of the housing. A plurality of cooling units connected to each other, a heat dissipating unit disposed outside the casing and releasing heat to the outside, and a water-cooling type that transmits heat of each cooling unit to the heat dissipating unit. a flow path of the cooling pipe has a water-cooled cooling system Ru provided with an inner diameter of the flow path of the cooling tube, the shape and at least one of the length, each of the respective cooling portions are connected LED lamp unit Characterized in that it is set to the power so that the flow rate corresponding, is achieved by the LED lamp for a vehicle.

  In the LED lamp according to the present invention, preferably, the heat dissipating part is dissipated by natural air cooling.

  In the LED lamp according to the present invention, preferably, the heat dissipating part is radiated by forced air cooling using an air cooling fan or the like.

  In the LED lamp according to the present invention, preferably, the cooling capacity of each LED lamp unit is adjusted by the inner diameter, shape and length of the flow path of the cooling pipe.

  The LED lamp according to the present invention is preferably adjusted so that the cooling capacities of the LED lamp units are the same.

  In the LED lamp according to the present invention, preferably, the cooling pipe has a surface area as large as possible in each cooling section.

  In the LED lamp according to the present invention, preferably, the cooling capacity of each of the LED lamp units is adjusted according to the input power to the LED lamp unit.

  In the LED lamp according to the present invention, preferably, the cooling capacity of each of the LED lamp units is adjusted so that the cooling units corresponding to the LED lamp units have the same temperature.

  In the LED lamp according to the present invention, preferably, the cooling capacity of each LED lamp unit is such that one cooling pipe is branched from each other so that the cooling units corresponding to the LED lamp unit have the same temperature. Connected to the department.

  According to the said structure, by supplying electric power from the exterior with respect to the LED element of each LED lamp unit, each LED element is driven and light-emits. And the light radiate | emitted from each LED lamp unit is irradiated toward the front through the said front lens.

In this case, the heat generated in the LED elements of each LED lamp unit is transmitted from the cooling unit thermally connected to the LED lamp unit to the heat dissipation unit via the cooling pipe. And each LED lamp unit will be cooled reliably by thermally radiating outside from this heat radiating part by natural air cooling or forced air cooling.
Thereby, the LED element of each LED lamp unit will be hold | maintained at comparatively low temperature, and the fall by the temperature rise of the luminous efficiency of each LED element can be suppressed.

Here, since each LED lamp unit can be cooled to a predetermined temperature without measuring the temperature of at least one LED element or LED lamp unit for cooling, the luminous efficiency of the LED element can be stabilized. It will be.
Even if the ambient temperature changes, each LED lamp unit can be always cooled to the same temperature by water cooling, so that the light emission efficiency of the LED element is always stable.

  When the cooling capacity for each LED lamp unit is adjusted by the inner diameter, shape, and length of the flow path of the cooling pipe, the cooling capacity in each LED lamp unit can be set to a predetermined value by these adjustments. At the same time, it is not necessary to constantly monitor the temperature of the LED elements and control the cooling capacity, so that it can be configured at a low cost with a simple configuration.

  When the cooling capacities relating to the LED lamp units are adjusted to be the same as each other, the LED lamp units can be uniformly cooled by the same cooling capacities.

  When the cooling pipe has a surface area as large as possible in each cooling section, the cooling capacity of the cooling pipe can be increased as much as possible.

  When the cooling capacity regarding each LED lamp unit is adjusted according to the input power to the LED lamp unit, the cooling capacity corresponding to the amount of heat generated by the input power of each LED lamp unit can be set.

  When the cooling capacity for each LED lamp unit is adjusted so that the cooling units corresponding to the LED lamp units have the same temperature, each LED lamp unit is cooled to the same temperature, The luminous efficiency of the LED elements in the LED lamp unit becomes uniform with each other.

  When the cooling capacity for each LED lamp unit is connected to each cooling unit with a flow branching from each other so that the cooling units corresponding to the LED lamp unit have the same temperature, By setting the flow rate ratio of each cooling pipe to a preset value, each LED lamp unit is cooled to the same temperature with a simple configuration.

Thus, according to the present invention, in an LED lamp having a plurality of LED lamp units, for example, a vehicle LED lamp such as an automobile LED headlamp, the cooling units to which the heat generated in each LED lamp unit corresponds respectively. Is transmitted to the heat radiating part through the corresponding cooling pipe and radiated to the outside.
As a result, each LED lamp unit is cooled based on the cooling capacity of the corresponding cooling unit and cooling tube, so that the luminous efficiency of the LED elements of each LED lamp unit does not decrease due to temperature rise. It can be maintained at a relatively high luminous efficiency.
Furthermore, the cooling capacities of the corresponding cooling tubes for each LED lamp unit are adjusted to be the same with each other, according to the input power to each LED lamp unit, or so that each LED lamp unit has the same temperature. As a result, the luminous efficiencies of the individual LED elements of each LED lamp unit are made uniform, and the occurrence of uneven brightness can be suppressed.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to FIGS.
The embodiments described below are preferable specific examples of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. As long as there is no description of the effect, it is not restricted to these aspects.

[Example 1]
FIG. 1 shows the configuration of an embodiment of an LED lamp according to the present invention.
In FIG. 1, an LED lamp 10 is an LED headlamp for an automobile, and a resin casing 11 having an open front surface and a plurality of (two in the illustrated case) provided in the casing 11. LED wrap unit 12, front lens 13 made of a translucent resin material attached to housing 11 so as to cover the front surface of housing 11, and cooling system 20.

Each LED lamp unit 12 includes at least one LED element, and is supported inside the casing 11 by a lamp unit support 14 so as to emit light forward.
Here, each LED lamp unit 12 includes, for example, an LED element 12a, a reflector 12b, a projection lens 12c, and a shutter 12d. The light emitted from the LED element 12a is converged by the reflector 12b, and is projected. Irradiation is performed forward by 12c, and a cut-off line is formed by shutter 12d.

The above configuration is the same as that of the conventional LED lamp 1 shown in FIG. 5, but the LED lamp 10 according to the embodiment of the present invention further includes a cooling system 20 for cooling each LED lamp unit 12. It has a different structure.
The cooling system 20 includes a plurality of cooling stages 21 as cooling units, a heat radiating unit 22, and a plurality of cooling pipes 23.

Each cooling stage 21 is fixed to the lamp unit support 14 and the corresponding LED lamp unit 12 is thermally connected.
Further, each of the cooling stages 21 includes a flow path (not shown) for cooling water from a cooling pipe 23 described later.
This flow path is preferably formed to have as large a surface area as possible in the cooling stage 21.

The heat radiating portion 22 is disposed outside the housing 11 and includes appropriate heat radiating means (not shown).
For example, when the heat radiating portion 22 is naturally air-cooled, the heat radiating means is constituted by a heat radiating fin that radiates heat by an air flow.
When the heat radiating unit 22 is forcibly air-cooled, the heat radiating means further includes an air cooling fan 22a (see FIG. 2).

The cooling pipe 23 penetrates the casing 11 from the heat radiating portion 22 to the cooling stages 21 so as to circulate a coolant such as cooling water from the heat radiating portion 22 to each cooling stage 21 and again to the heat radiating portion 22. Has been routed to.
At this time, the cooling pipe 23 is branched in the middle and guided to the cooling stages 21, and is coupled to the cooling stages 21 in the middle to return to the heat radiating unit 22.

  Here, specifically, the cooling system 20 is, as schematically shown in FIG. 2, from the heat radiating unit 22 via the cooling pipe 23 by a circulation pump 24 provided in the middle of the cooling pipe 23. A refrigerant such as cooling water is circulated through each cooling stage 21 and a reservoir tank 25 for replenishing the refrigerant is provided.

Further, when each LED lamp unit 12 is driven with the same power, the cooling pipe 23 is branched so that the flow rate of the refrigerant is equally divided, and the refrigerant is supplied to each cooling stage 21 at the same flow rate. It has become.
At that time, each of the branched cooling pipes 23 is formed so that the inner diameter, the shape, and the length of the flow path are the same with respect to the corresponding cooling stage 21 including the inside of the cooling stage 21. Uniform cooling capacity is provided.

  When each LED lamp unit 12 is driven with different power, the cooling tube 23 sets a flow rate ratio for the corresponding cooling stage 21 according to the power of each LED lamp unit 12, and this flow rate ratio is set. And the refrigerant is supplied to each cooling stage 21.

In this way, the cooling pipes 23 are branched at a flow rate ratio selected so that each cooling stage 21 and the corresponding LED lamp unit 12 have the same temperature, and are led to the cooling stage 21 respectively. .
That is, as shown in FIG. 3, with respect to the LED lamp unit 12 driven by electric power A, B (W), the corresponding cooling stage 21 has a flow rate ratio a: b, for example, flow rates a, b (ml / s ), The cooling stage 21 can be cooled to the same temperature by supplying the refrigerant from the circulation pump 24 at a flow rate a + b (ml / s).

The LED lamp 10 according to the embodiment of the present invention is configured as described above. By supplying power to the LED lamp units 12 from the outside, the individual LED elements of the LED lamp units 12 are driven to emit light. .
Then, the light emitted from each LED lamp unit 12 is irradiated forward through the front lens 13.

In this case, the heat generated by the individual LED elements of each LED lamp unit 12 is transmitted to the corresponding cooling stage 21.
Further, the heat moves to the heat radiating unit 22 through the cooling pipe 23 by the refrigerant flowing in the cooling stage 21.
As a result, heat is discharged to the outside by natural air cooling or forced air cooling in the heat radiating section 22.

In this way, the heat generated in the individual LED elements is moved to the heat radiating section 22 by the refrigerant flowing from the LED lamp units 12 and the cooling stage 21 through the cooling pipe 23 and discharged to the outside.
At that time, the coolant branched into each cooling stage 21 at a predetermined flow ratio flows, whereby each cooling stage 21 and each LED lamp unit 12 are cooled to the same temperature.
Accordingly, the individual LED elements of each LED lamp unit 12 are maintained at substantially the same temperature, so that the light emission efficiency of each LED element becomes substantially constant, and brightness unevenness can be suppressed as a whole of the LED lamp 10. Become.

In order to confirm the cooling effect of the LED lamp 10 according to the above-described embodiment, an experiment was performed as follows.
That is, as the cooling system 20, for example, a water cooling kit P / N: A1604 manufactured by Thermaltake is used, and the circulation pump 24 is driven and controlled so that the total flow rate becomes 9 ml / s, and the cooling stage 21 is ceramic heater. The temperature of the cooling stage 21 was measured 20 minutes after the power was turned on, and the cooling capacity was tested.

As a result, as shown in FIG. 4, the temperature of the cooling stage 21 is 39.2 ° C., 43.5, as shown, with respect to the electric power 42W, 57W, 72W supplied to the LED lamp unit 12, respectively. And 47.8 ° C.
Subsequently, when the flow rate is branched to 6 ml / s and 3 ml / s and the cooling stage 21 is cooled under the same conditions, the temperature of the cooling stage 21 is, as shown in FIG. , 72W, when the flow rate is 6 ml / s, they are 40.5 ° C, 45.2 ° C and 50.1 ° C, respectively, and when the flow rate is 3 ml / s, they are 43.0 ° C, 48.7 ° C and 54 ° C, respectively. It was 3 ° C.

  In this way, by appropriately setting the flow rate ratio to each cooling stage 21 in advance, the cooling temperature of each cooling stage 21 can be achieved with a simple configuration without using a conventional temperature sensor and control circuit. Can be set to the same temperature.

In the above-described embodiment, the two LED lamp units 12 and the two cooling stages 21 corresponding thereto are provided. However, the present invention is not limited to this, and the LED lamp includes three or more LED lamp units 12. It is clear that the present invention can be applied to 10.
In this case, a cooling stage 21 is provided corresponding to each LED lamp unit 12, and a cooling pipe 23 is branched and guided to each cooling stage 21.

  The LED lamp 10 according to the present invention is configured as an automotive LED headlamp, but is not limited to this, and other types of vehicle LED lamps including auxiliary headlamps, and various LEDs for illumination, etc. The present invention can be applied to a lamp.

  Thus, according to the present invention, even when a plurality of LED lamp units are included, each LED lamp unit is reliably cooled with a simple configuration, and preferably each LED lamp unit is kept at a uniform temperature. It would be possible to provide an LED lamp that is to be obtained.

It is a schematic sectional drawing which shows the structure of one Embodiment of the LED lamp by this invention. It is a block diagram which shows the structural example of the cooling system in the LED lamp of FIG. It is a figure explaining the branch of the cooling pipe in the LED lamp of FIG. It is a figure which shows the temperature of the cooling stage by the electric power supplied to the LED lamp unit by the experiment example corresponding to the LED lamp of FIG. 1, and a refrigerant | coolant flow rate. It is a schematic sectional drawing which shows the structure of an example of the conventional LED lamp. It is a graph which shows the relationship between the emitted light beam of a general LED element, and temperature.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 LED lamp 11 Case 12 LED lamp unit 13 Front lens 14 Lamp unit support body 20 Cooling system 21 Cooling stage (cooling part)
22 Heat Dissipation Section 23 Cooling Pipe 24 Circulation Pump 25 Reservoir Tank

Claims (9)

A front-opened housing, a plurality of LED lamp units each having at least one LED element arranged so as to irradiate light forward in the housing, and opening the housing A front lens made of a translucent material that closes the front surface, and an LED lamp comprising:
A plurality of cooling units to which the LED lamp units are thermally connected;
A heat dissipating part that is disposed outside the housing and emits heat to the outside;
Has a water-cooled cooling system Ru and a flow path of the cooling tube water-cooled to transmit the respective cooling portions of the heat to each said heat radiating portion,
At least one of the inner diameter, shape, and length of the flow path of the cooling pipe is set to have a flow rate corresponding to the power of each LED lamp unit connected to each cooling section. LED lamp. A front-opened housing, a plurality of LED lamp units each having at least one LED element disposed so as to irradiate light forward in the housing, and the opening of the housing A front lens made of a translucent material that closes the front surface, and a vehicle LED lamp comprising:
A plurality of cooling units to which the LED lamp units are thermally connected;
A heat dissipating part that is disposed outside the housing and emits heat to the outside;
Has a water-cooled cooling system Ru and a flow path of the cooling tube water-cooled to transmit the respective cooling portions of the heat to each said heat radiating portion,
At least one of the inner diameter, shape, and length of the flow path of the cooling pipe is set to have a flow rate corresponding to the power of each LED lamp unit connected to each cooling section. LED lamps for vehicles.   The LED lamp according to claim 1, wherein the heat radiating part is radiated by natural air cooling.   3. The LED lamp according to claim 1, wherein the heat dissipating part is radiated by forced air cooling using an air cooling fan or the like. The LED lamp according to claim 1 , wherein the cooling capacities of the LED lamp units are adjusted to be the same. The in each cooling portion, characterized in that the cooling tube has a largest possible surface area, LED lamp according to any one of claims 1 to 5. The LED lamp according to any one of claims 1 to 6 , wherein the cooling capacity of each LED lamp unit is adjusted according to the input power to the LED lamp unit. The LED lamp according to any one of claims 1 to 6 , wherein the cooling capacity of each of the LED lamp units is adjusted so that the cooling units corresponding to the LED lamp units have the same temperature. . The cooling capacity of each LED lamp unit is characterized in that one cooling pipe is branched from each other and connected to each cooling unit so that the cooling units corresponding to the LED lamp unit have the same temperature. The LED lamp according to claim 1 .

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