JP2010114060A - Led lighting fixture - Google Patents

Abstract

The main object of the present invention is to overcome the defects of a radiator of a high-power LED, to provide a more efficient heat dissipation structure for the LED lighting apparatus, to be beautiful in appearance, and to have high practical value. Is to provide an instrument.
A radiator (14) includes a heat radiating hollow cylindrical body (15) and a plurality of heat radiating rods (2) on the surface of the heat radiating hollow cylindrical body (15). As shown in FIG. 3, two adjacent rods 2 are connected to the bottoms 4 of all the rods 2 connected to the heat radiating hollow cylindrical body 15, and all the heat radiating rods 2 are at a predetermined angle R in the same direction. It is inclined, and the front and rear surfaces of each heat sink 2 are formed into wave-like waves (wave surface) 3 with bumpy undulating water.
[Selection] Figure 3

Description

  The present invention relates to an LED lighting apparatus using a light emitting diode as a light source.

Traditional incandescent lamps are gradually being despised with the shortage of global energy such as oil and the growing demand for environmental protection.
On the other hand, fluorescent lamps, energy-saving lamps, etc. are popular, but they must use harmful substances such as mercury during the production process, so they meet energy-saving requirements but meet environmental protection requirements. Can not.
In this situation, high power LED chips have been successfully researched and manufactured with the continuous research and development of light emitting semiconductor technology.
High power LED chip has high brightness, good color appearance, high luminous efficiency, low driving voltage, long service life, no UV, no harmful metals, convenient installation, etc. Because of its advantages, in the 21st century it can replace the light sources of traditional lighting fixtures and is expected to play a leading role in the lighting market.

However, since the high power LED chip is integrated by connecting a single LED in a certain series and parallel, the drive current is large, and the current high power LED chip generates a large amount of heat while being energized. .
The constant current drive power supply for LED lighting fixtures used on a daily basis is built in the lamp cup, so the operating environment is bad, and the amount of heat generated during energization of the LED chip is introduced into the lamp cup. Will be. Further, the rapid rise in temperature of the LED chip causes a rapid decay of light emission, which may destroy the LED chip.

Measurement of a large amount of data reveals that the ambient temperature in the lamp cup and the temperature at the bottom of the LED chip are basically in the same range.
One technical means for solving these problems is related to a radiator (radiator). For example, Patent Document 1 discloses a multi-chip LED illumination lamp including a casing provided with multistage radiating blades. However, if the heat dissipation technology of the radiator of the high power LED is solved, the light decay of the LED can be delayed to the maximum and the service life of the LED lighting apparatus can be increased. Therefore, high power LED radiator design research is a problem to be solved quickly in the industry.

On the other hand, when the environmental temperature in the lamp cup exceeds the operating temperature of the external environment of the LED lighting apparatus, the high temperature causes the LED chip light to decay at an accelerated rate, greatly affecting its lifetime.
As technical means for solving this problem, for example, Patent Document 2 discloses a temperature sensor 9 for detecting an environmental temperature, a cooling fan 20 and the like.

JP 2008-186758 A Japanese Patent Laid-Open No. 2004-246047

The problem to be solved by the present invention is, firstly, overcoming the defects of the radiator of the high power LED, researching and designing again, providing a more efficient heat dissipation structure for the LED lighting fixture, It is to provide a beautiful and practical LED lighting fixture.
Secondly, the LED chip constituting the LED lighting apparatus is protected from thermal stress or the like. Specifically, the temperature of the LED chip is inspected and measured, and corresponding protection measures are taken to provide a configuration to stop the operation before reaching the extreme temperature value. Third, It is how to provide a configuration for protecting the LED chip against lightning in summer.

In order to solve the first problem, the present invention provides a kind of new structure radiator, and subdivides the heat dissipation structure of the LED radiator into five parts.
That is: LED chip, 2. 2. Heat conducting part (direct contact part with LED); 3. Heat-transfer wall (the surface of the heat-transfer block and the contact portion); 4. Heating part (metal part between the heat transfer wall and the radiator radiating outer surface) Divide into heat dissipation part (radiator external surface).
Among these subdivisions, the most ideal radiator structure is the amount of heat generated during the work of the LED chip = the amount of heat derived from the heat conducting portion = the amount of heat derived from the heat transfer wall = memory (stored) in the heat capacity portion. The amount of heat generated is the amount of heat generated per second of the heat generating part (LED chip), and the problem to be solved by the radiator is to satisfy the above equation.
That is, the most important problems are to increase the number of heat sinks (of the radiator), the surface area of the heat sink and the mass incorporating the LED chip (corresponding to the heat conducting part) and the radiator hollow wall (heat capacity part). This is achieved by tying together and efficiently dissipating the heat generated during the work of the LED chip to the outside through the radiator outer surface.

The present invention relates to a constant current drive circuit of a kind of LED chip, and is a constant current drive circuit having a function to prevent overheating and lightning, and in particular, to solve the second and third problems, a light emitting diode. The LED lighting apparatus includes a main body, an LED constant current driving circuit accommodated in the main body, and a commercial power supply connection unit that supplies power to the LED constant current driving circuit. The LED constant current driving circuit includes an overheat protection circuit, an overvoltage protection circuit for preventing lightning, a rectifier circuit, a power management chip, and a photocoupler feedback circuit, and the power management chip receives a feedback signal of the photocoupler feedback circuit. Based on this signal, the operation of the LED constant current drive circuit is controlled, and the LED constant current drive is controlled. It is possible to realize the input function of the wide voltage of the circuit, and the LED lighting apparatus characterized in that it comprises a PWM control function.
The present invention provides a kind of isolated LED constant current driving circuit, and the feature of this electric circuit is that the reliability of the isolated LED constant current driving circuit is high, and it has an overheat protection function and a lightning strike prevention function, At the same time, it also has a soft start function.

According to the present invention, it is possible to increase the number of radiator radiating rods, and firmly connect the surface area of the radiating rod and the mass incorporating the LED chip (corresponding to the heat conducting portion) and the radiator hollow wall (heat capacity portion). It is possible to provide an LED lighting device that can be combined and efficiently dissipate heat generated during the work of the LED chip to the outside through the radiator outer surface.
In addition, according to the present invention, it is possible to provide an LED lighting device including an LED constant current drive circuit that has a high reliability of the isolated LED constant current drive circuit and that exhibits an overheat protection function and a lightning strike prevention function.

FIG. 1 is a perspective view of a bulb-type LED lamp as an LED lighting apparatus of Example 1. FIG. FIG. 2 is a perspective view from above of a radiator (heat dissipating part) used in the lamp, to which a pressing mass is attached. FIG. 3 is a cross-sectional view of the heat radiating portion. FIG. 4 is a perspective view from below (bottom surface) of the heat dissipating part used in the lamp. FIG. 5 is a perspective view before the pressing mass from above the heat radiating portion is attached. FIG. 6 is a cross-sectional view of a circular pressing mass on which the LED chip is placed. FIG. 7 is a perspective view of a light bulb type LED lamp as an LED lighting apparatus of Example 2. FIG. FIG. 8 is a perspective view of a light bulb type LED lamp as an LED lighting apparatus of Example 3. FIG. FIG. 9 is a longitudinal sectional view of the lamp. FIG. 10 is a circuit diagram of an LED constant current driving circuit used in the LED lighting apparatus.

  The LED lighting apparatus 10 of the present invention includes a main body 11, an LED constant current drive circuit 12 accommodated in the main body 11, and a commercial power supply connection portion 13 that supplies electric power to the LED constant current drive circuit 12. is there. The first embodiment is a light bulb type LED lamp as shown in FIG. 1, and a radiator 14 is provided in the main body 11.

2 to 5, the radiator 14 includes a heat radiating hollow cylindrical body 15 and a plurality of heat radiating rods 2 on the surface of the heat radiating hollow cylindrical body 15. As shown in FIG. 3, two adjacent rods 2 are connected to the bottoms 4 of all the rods 2 connected to the heat radiating hollow cylindrical body 15, and all the heat radiating rods 2 are at a predetermined angle R in the same direction. It is inclined, and the front and rear surfaces of each heat sink 2 are formed into wave-like waves (wave surface) 3 with bumpy undulating water.
A circular pressing mass (corresponding to a heat transfer mass) 7 having a chip mounting portion (corresponding to a heat conducting portion) 1 on which an LED chip is placed as shown in FIG. .
As shown in FIGS. 3 to 5, the surface of the hollow inner wall (surface of the heat radiating hollow wall) 5 under the circular pressing mass 7 fitted in the heat radiating hollow cylindrical body 15 has a large number of semi-circular grooves 50 ringed around the wall. And are connected.

  As shown in FIG. 1, the overall shape of the radiator (hereinafter, also referred to as a heat radiating portion) 14 may include a tapered surface 17 whose diameter decreases toward the base of the commercial power supply connection portion 13. However, as shown in FIG. 7, a tapered surface 17 toward the light emitting window 18 may be provided.

As shown in FIG. 3, the detailed heat dissipating rod 2 includes first branch portions 20, 20 that protrude from the surface of the heat capacity portion 8 in a direction of 360 degrees from the central axis O of the heat radiating hollow cylindrical body 15. And second branches 21, 21... Branching from the bottoms 4 of the first branches 20, 20,.
The first branch portion 20 and the second branch portion 21 are formed in a thin plate shape along the central axis O so that the free end (end portion) of the second branch portion 21 forms a cylindrical generatrix. It is formed as follows.
The second branch portion 21 of the heat dissipation rod 2 is inclined at a predetermined angle R from the bottom 4 of the flange 2, but the first branch portion 20 is also inclined at an acute angle smaller than the predetermined angle R. Also good.
Further, although it is formed with a predetermined curvature along the arc r passing through the center O of the heat radiating hollow cylindrical body 15, it may be formed linearly with the predetermined angle R.

As described above, by providing the second branch portion 21 that branches into the fork from the bottom 4 of the first branch portion 20, the number of the heat dissipation rods 2 is increased, and each of the heat dissipation rods 2 is increased. The length of the heat sink 2 is increased by inclining in the same direction.
Moreover, the surface of all the heat sinks 2 is formed in the shape of water-like waves 3 to increase the heat dissipation surface area of the heat sinks.
Therefore, such a configuration solves the problem of insufficient heat dissipation area.

  The hollow inner wall of the heat radiating hollow cylindrical body 15 is formed with a fitting portion (step) 6 of the circular pressing mass 7 as shown in FIG.

  The hollow cylindrical heat dissipating part 14 configured as described above is integrally formed by extruding from a mold, and cuts the steps according to the length according to the demand to dissipate heat from LED chips of different power sizes. Use.

  Then, the circular pressing mass 7 for mounting the LED chip is attached to the heat radiation part 14 of the hollow cylinder, and the diameter of the circular pressing mass 7 and the diameter of the heat radiation hollow cylindrical body 15 (the inner diameter ID of the upper inner wall ID refer to FIG. 5). Or larger than the diameter of the empty heat-dissipating hollow cylinder 15 to more firmly connect the two metal parts to increase the temperature transfer speed.

When the diameter of the circular pressing mass 7 is the same as the diameter (inner diameter) of the radiating hollow cylindrical body 15 or when the diameter of the circular pressing mass 7 is larger than the diameter (inner diameter) of the radiating hollow cylindrical body 15, A situation occurs in which the circular pressing mass 7 of the LED chip cannot be attached to the cylindrical heat radiation portion 14. In order to solve this technical challenge, after several tests, the shrinkage due to metal cooling and the thermal expansion were studied.
As a result, fitting of the circular pressing mass 7 to the upper inner wall 19 of the heat radiating hollow cylindrical body 15 is performed by expanding the heat radiating bowl 2 (heat radiating hollow cylindrical body 15) in an oven at 160 ° C. to 240 ° C., The circular pressing mass 7 is put into a freezing facility at −10 ° C. to −16 ° C. and then contracted, and then fitted into the upper inner wall 19 of the circular pressing mass 7. For example, the circular pressing mass 7 is contracted by cooling with a punching device. The presser mass 7 is put in the inner wall 19 of the heat-radiating portion 14 of a hollow cylinder that has been thermally expanded.

In addition, as shown in FIG. 6, in order to reduce the weight of the whole lighting fixture, the accommodation space of internal power supplies (LED constant current drive circuit 12 grade | etc.,) Is increased, and the cross-sectional trapezoid shape is formed in the lower part of the said circular pressing lump 7. The weight of the circular pressing mass was effectively reduced without affecting the heat transfer between the circular pressing mass 7 and the hollow cylindrical heat radiation portion inner wall 19. The shape of the recess may be substantially conical (see FIG. 9).
In addition, as shown in FIG. 8, the light emission window 18 is enlarged to such an extent that the outer periphery of the light emission window 18 is substantially coincident with the outer diameter 14 a of the radiator 14, and the region is about half of the dimension M of the outer periphery 14 b of the radiator 14. A taper surface 17 may be provided.
With this configuration, the entire illumination range can be expanded and the weight of the instrument can be reduced.

  As shown in FIG. 10, the LED constant current drive circuit 12 includes a rectifier 30 that rectifies and smoothes commercial AC power, a transformer T1 that transforms (steps down) the output from the rectifier circuit 30, and a transformer T1. An LED lighting circuit 31 for lighting a light emitting diode with the output of the power supply as a power source, and a photocoupler feedback circuit 32 for making the primary side and the secondary side of the transformer T1 electrically separable and controlling the output voltage. Yes.

A self-recovering temperature fuse F1 that constitutes an overheat protection circuit is connected in series at the input end side of the rectifier circuit 30 in front of it.
This self-healing thermal fuse F1 can be selected for its operating parameters according to different operating locations, and when the environment around the constant current drive exceeds the operating value of the self-healing thermal fuse F1. The self-recovering temperature fuse F1 starts to operate, and all the drive circuits are in a cut-off protection state.
Then, the LED chip stops its operation, waits for the temperature of the lamp cup of the main body 11 to fall below the initial operating value of the self-recovering temperature fuse F1, the drive is recovered, and the LED chip starts working again. start.

A varistor RV constituting an overvoltage protection circuit is connected in parallel to the input end side.
The main function of the varistor RV is to protect the circuit from a momentary overvoltage and to protect the circuit from lightning strikes.

  In the rectifier circuit 30, the commercial alternating current is rectified through the rectifier bridge circuit D1, and then filtered twice through C1 and C2.

A power management chip U <b> 1 is connected to the output terminal of the rectifier circuit 30.
The power management chip U1 is a VIPER 12A and can work in a wide input voltage range (85 to 265 VAC).
One of the pins 1 and 2 of the power management chip U1 is connected to the output terminal B of the rectifier circuit 30, and the other is connected to the port 4 of the feedback coil of the transformer T1.
The lead 3 (feedback input terminal) of the power management chip U1 receives one feedback signal from the photocoupler U2 (circuit 32), and the other is connected to the feedback port 4 of the transformer T1 through the capacitor C4.
The lead 4 of the power management chip U1 is connected to one photocoupler U2 (circuit 32), and the other is connected to the feedback port 4 of the transformer T1 through the capacitor C5.
The leads 5, 6, 7, and 8 of the power management chip U1 are connected to the elementary coil ports 1 and 2 of the transformer T1 by being connected to the diodes D2, R1, and C3.

The feedback coil port 3 of the transformer T1 is connected to the lead 4 of the power management chip U1 via R2 and the diode D3.
The secondary coil 8 of the transformer T1 is connected to the positive pole of the output terminal by being connected to the diode D4.

The common action of the capacitors C6 and C7 ensures long-time operation of the LED chip by greatly removing output ripple and noise values.
The constant current drive output current is controlled by the operational amplifier U3 and the current limiting resistors R8 and R9.

  When the all constant current driving circuit is operated, the positive terminal of the light emitting diode chip LED for illumination as a load is connected to the connection point of the diodes D4 and D5, the capacitors C6 and C7, and the resistor R4, and the negative terminal thereof is the resistor R8 and the resistor. Connected to the connection point of R9.

  The light emitting element of the photocoupler U2 of the photocoupler feedback circuit 32 is connected in parallel to the LED lighting circuit 31, and the amount of emitted light is fed back as described above.

The specific route for realizing the above idea is as follows.
A wide range of alternating current (100-240V) is input, through the rectification of the rectification bridge circuit D1, is converted into a direct current, through the double filtering of C1, L1, C2, the cathode is the pins 1 and 2 of the power management chip VIPER 12A And the anode is connected to port 1 of the transformer T1. The power management chip VIPER 12A can accept a wide voltage input.
One of the pins 1 and 2 of the power management chip VIPER 12A is connected to the output terminal B of the rectifier circuit, the other is connected to the feedback coil port 4 of the transformer T1, and the lead 3 (feedback input terminal) is one photocoupler. The feedback signal from U2 is received, the other is connected to the feedback port 4 of the transformer T1 through the capacitor C4, the lead 4 is connected to one photocoupler U2, and the other is connected to the feedback port 4 of the transformer T1 through the capacitor C5. Connected.
The leads 5, 6, 7, and 8 of the power management chip are connected to the elementary coil ports 1 and 2 of the transformer T1 by being connected to the diodes D2, R1, and C3.

The feedback coil port 3 of the transformer T1 is connected to the lead 4 of the power management chip through R2 and the diode D3.
The secondary coil 8 of the transformer T1 is connected to the “+” pole of the output terminal by being connected to the diode D4.
The common action of the capacitors C6 and C7 ensures long-time operation of the LED chip by greatly removing output ripple and noise values.
The operational amplifier U3 and the current limiting resistors R8 and R9 commonly control the constant current output of the electric circuit.

The varistor RV can protect against overvoltage and can effectively prevent lightning.
The self-recovering temperature fuse F1 can provide an overheat protection function.
When the full constant current driving circuit is activated, the positive terminal of the light emitting diode chip LED for illumination as a load is connected to the connection point of the diodes D4 and D5, the capacitors C6 and C7 and the resistor R4, and the negative terminal is the resistor R8 and the resistor R9. Connected to the connection point.

The LED constant current drive circuit of the present invention has the following characteristics.
1. A self-recovering temperature fuse is added in the drive circuit to provide a good overheat protection function for the entire LED lamp (including the power supply drive and the LED chip).
2. The varistor RV at the output terminal of the drive circuit effectively functions to prevent lightning strikes.
3. The entire drive circuit has a PWM control function, an overheat protection function, an overvoltage protection function and an overcurrent protection function with the chip VIPER12A of ST Microelectronics Co., Ltd. as the core of control. At the same time, a wide voltage output requirement (85 to 265 VAC) within the world range can be satisfied.
4. The electric circuit adopts photocoupler U2 to isolate high and low pressure. This is the topology of the entire drive circuit.
5. Resistors R4, R6, R7, R8, R9, capacitors C6, C7, diode D5, photocoupler U2 and 2-line operational amplifier U3 together form an isolation feedback circuit and a filtering circuit to stabilize the voltage of the constant current. Ensures output, lowers ripple and noise, and provides overcurrent and open circuit protection.
6. A wide range of voltages from 100V to 240VAC can be accepted.

  The above embodiment is a bulb-type LED lamp as an LED lighting apparatus, but the present invention is applied to a fluorescent-type LED lamp, a spotlight-type LED lamp, a downlight-type LED lamp, a desk lamp, a ceiling light, and a mall light. Can be used.

DESCRIPTION OF SYMBOLS 1 Chip mounting part 2 Heat radiation pad 3 Wave (wave surface) 4 Bottom of coral 5 Surface of hollow inner wall (surface of heat radiation hollow wall)
6 Circular presser inset (step)
7 circular holding block 8 heat-contained part 10 LED lighting fixture 11 main body 12 LED constant current drive circuit 13 commercial power supply connection part 14 radiator 14a outer diameter 14b outer periphery 15 heat radiating hollow cylindrical body 17 taper surface 18 light emitting window 19 upper inner wall 20 first Branch portion 21 Second branch portion 30 Rectifier circuit 31 LED lighting circuit 32 Photocoupler feedback circuit 50 Recessed groove R Predetermined angle R
O Center of heat radiating hollow cylinder r Arc T1 Transformer F1 Self-healing temperature fuse RV Varistor D1 Rectifier bridge circuit U1 Power management chip U2 Photocoupler (photocoupler)
U3 operational amplifier

Claims (12)

In LED lighting fixtures using light emitting diodes as light sources,
The LED lighting apparatus includes a main body, an LED constant current drive circuit accommodated in the main body, and a commercial power supply connection unit that supplies power to the LED constant current drive circuit.
The main body is provided with a radiator,
The radiator includes a heat radiating hollow cylinder and a plurality of heat radiating ridges on the surface of the heat radiating hollow cylinder, and two adjacent ridges are connected to the bottoms of all the ridges connected to the heat radiating hollow cylinder, All the heat sinks are inclined in the same direction at a predetermined angle R, and the front and rear surfaces of each heat sink are formed in a wave pattern of uneven water.   The LED lighting apparatus according to claim 1, wherein a circular pressing lump on which the LED chip is placed is fitted in an upper inner wall of the heat radiating hollow cylindrical body.   The LED lighting apparatus according to claim 2, wherein a recess having a trapezoidal cross section is formed as a groove recessed in a circular shape at a lower portion of the circular pressing mass.   The LED illuminator according to claim 2 or 3, wherein a material of the heat radiating hollow cylindrical body and the circular pressing mass is copper or a copper alloy.   5. The LED lighting apparatus according to claim 2, wherein a diameter of the circular pressing mass is substantially equal to or larger than an inner diameter of an upper inner wall of the heat radiating hollow cylindrical body.   6. The LED lighting device according to claim 1, wherein a plurality of semi-circular grooves are connected to each other as a ring on the surface of the hollow inner wall of the heat radiating hollow cylindrical body. .   6. The LED lighting apparatus according to claim 5, wherein the fitting of the circular pressing mass to the upper inner wall utilizes an action of expanding when heated and contracting when cooled.   To fit the circular pressing mass to the upper inner wall, expand the radiator by placing it in an oven at 160 to 240 degrees, and shrink the circular pressing mass into a freezing facility at -10 to -16 degrees, The LED lighting apparatus according to claim 2, wherein the circular pressing mass is placed in the upper inner wall. The LED constant current drive circuit includes an overheat protection circuit, an overvoltage protection circuit that prevents lightning, a rectifier circuit, a power management chip, and a photocoupler feedback circuit.
The power management chip receives a feedback signal of a photocoupler feedback circuit, controls the operation of the LED constant current drive circuit based on this signal, and realizes a wide voltage input function of the LED constant current drive circuit, The LED lighting apparatus according to claim 1, further comprising a PWM control function.   The LED lighting apparatus according to claim 9, wherein the overheat protection circuit includes a protection function of a self-recovering temperature fuse and a heating protection function built in the power management chip.   The LED lighting apparatus according to claim 9, wherein the overvoltage protection circuit includes a varistor protection function and an overvoltage protection function built in the power management chip.   The LED lighting apparatus according to claim 9, wherein the power management chip is a VIPER 12A chip.