RU2650346C1 - Method of design of a lighting device, led lamp - Google Patents

Abstract

FIELD: lighting equipment.

SUBSTANCE: group of inventions relates to constructions of lighting devices, in particular to constructions of LED lamps. LED lamp and the method of its construction include a LED light source, mounted on the heat-conductive body, light-transmitting cover installed above the LED light source, light-transmitting solidifying compound, filling the cavity between the LED light source installed on the heat-conducting body and the light-transmitting cover. Light-transmitting cover is made in the form of a flexible light-transmitting envelope made of a rigid thermo-deformable material, and the light-transmitting solidifying compound is made in the form of elastic solidifying compound after hardening.

EFFECT: technical result is the creation of a method for designing lighting devices, the use of which allows reducing costs, increasing reliability, impact resistance, and resistance to collapse loads.

6 cl, 6 dwg

Description

The presented group of inventions relates to the design of lighting devices, in particular to the design of LED lamps and LED lamps.

Methods for manufacturing lighting devices are known from the prior art, in which, for the purpose of protection and sealing, light sources are coated with a translucent hardening compound. Known durable, waterproof lighting device (patent US 6595671 B2, publ. 07/22/2003). The water resistance of the known device is ensured by placing the LEDs in a monolithic light-transmitting enveloping medium. The disadvantage of the method of constructing a known device is the high cost of implementation associated with the complexity of manufacturing. To protect LEDs in a monolithic environment, there is a need to use a housing with a strong light-transmitting cover. Devices with the application of monolithic casting LEDs without an additional protective light-transmitting cover have low strength, since the resins used for monolithic casting are brittle in the array after hardening and have low resistance to wear of the surface of the array. In addition, the monolithic pouring of LEDs into an array itself requires the use of additional molds, which increases the cost of devices manufactured in this way.

The closest prototype of the first invention of the group, a method of constructing a lighting device, is the method used in the design of the LED lamp (utility model description to patent RU 117172 U1, publ. 20.06.2012). In the known solution, the problems of protecting the light-emitting element are solved by placing it in the recess of the housing and filling the recess with a translucent hardening compound, while the surface of the compound can be further protected by impact-resistant glass. A disadvantage of the known solution is the high cost of lighting devices made by this method, associated with the complexity of manufacturing a body with a recess and a translucent cover made of shockproof glass. In addition, with this method of designing lighting devices, a part of the light flux from the light-emitting element is lost due to its diaphragmation by the edges of the recess. In addition, impact-resistant glass breaks up into small fragments upon destruction, so such lamps cannot be used in food production.

The problem solved by the first invention of the group, connected by a single inventive concept of technical solutions, and the technical result achieved are to create a method for designing lighting devices, the use of which allows to reduce their cost, increase reliability, impact resistance and resistance to destructive loads.

To solve the problem and achieve the claimed technical result, in a method of designing a lighting device in which at least one LED light source is protected by a light-transmitting cover, and the cavity between the LED light source and the light-transmitting cover is filled with a light-transmitting hardening compound, a flexible light-transmitting cover is used as a light-transmitting cover the shell is made of hard material, and the cavity between the LED light source and the flexible light transmission guide light transmitting envelope filled with a hardening compound, elastic after hardening.

As a prototype of the group’s second invention, the LED lamp, a well-known solution was also chosen (utility model description for patent RU 117172 U1, published on June 20, 2012), in which the design of the LED lamp includes a monolithic housing with a recess, with a light-emitting element placed in the recess, while the notch is completely filled with a translucent compound, which can be protected by impact-resistant glass.

A disadvantage of the known solution is the high cost of the lamp, associated with the complexity of manufacturing a body with a recess and impact-resistant glass. In addition, luminaires with impact-resistant glass are of limited use, for example, in the food industry, since when destroyed, impact-resistant glass crumbles into numerous fragments. In addition, the known solution has low efficiency, since part of the luminous flux from the light-emitting element is diaphragmed by the edges of the recess.

The problem solved by the second invention of the group, and the technical result achieved are to reduce the cost, increase reliability, efficiency, resistance to destructive loads of the LED lamp.

To solve the problem and achieve the claimed technical result, in the LED lamp, consisting of an LED light source mounted on a heat-conducting housing, a light-transmitting cover installed above the LED light source, a light-transmitting hardening compound filling the cavity between the LED light source and a light-transmitting installed on the heat-conducting body cover, light-transmitting cover is made in the form of a light-transmitting flexible shell of hard thermally deformable material, and the light transmitting hardening compound is made in the form of an elastic, after hardening, light transmitting hardening compound.

Besides:

- LED light source consists of several LEDs;

- a flexible light-transmitting shell of hard thermo-deformable material has the shape of one or more lenses, which, in combination with a light-transmitting hardening compound, after hardening, have optical properties that form the direction of the light flux from the LED light source;

- a LED driver is installed in the cavity between the LED light source mounted on the heat-conducting body and the flexible light-transmitting shell of a rigid thermally deformable material filled with a light-transmitting hardening compound;

- in the cavity between the LED light source mounted on the heat-conducting casing and a flexible light-transmitting shell of rigid thermally deformable material filled with light-transmitting hardening compound, a thermal relay is installed with a shut-off temperature below the maximum operating temperature of the LED light source.

The closest analogue of the third invention of the group - the LED lamp, is the "LED lamp" (Description of the invention to patent RU 2546469 C2, publ. 04/10/2015). In the known solution, one or more LED strips (filaments) are used as a light source, which are mounted with a holder in an airtight chamber filled with gas having a low viscosity coefficient and high thermal conductivity. During operation, LED strips emit heat. The problem of heat removal from the LED strip is solved by heat fluxes and convection in the gas filling the chamber.

A disadvantage of the known solution is the limitation of the power of LED strips due to the low thermal conductivity of the gas filling the chamber and weak convection, which is associated with heating of the gas in a small volume. In addition, for long-term gas retention, it is necessary to use sealed glass flasks, which increases the cost of the lamp. In addition, the known device (LED lamp) has an increased fragility due to the use of glass.

The problem solved by the third invention of the group and the technical result achieved are to create the next technical solution for an LED lamp having high reliability, strength, efficiency, low cost.

To solve the problem and achieve the claimed technical result, in the LED lamp, consisting of a base for fixing and connecting to an external electrical circuit, the driver, at least one LED light source installed in the light-transmitting bulb, a heat-conducting substance filling the cavity of the light-transmitting bulb, bulb made in the form of a flexible light-transmitting shell of a rigid thermally deformable material, and the heat-conducting substance is made in the form of light-transmitting hardening its elastic after hardening of the compound.

Besides,

- LED light source consists of several LEDs;

- The LED lamp contains an additional base for fixing and connecting to an external electrical circuit.

The invention is illustrated by drawings, which depict:

In FIG. 1 - LED lamp (partially in section).

In FIG. 2 - LED lamps with a matte and transparent diffusers.

In FIG. 3 - LED lamp (in section),

In FIG. 4 - LED lamp with a convex-concave shell.

In FIG. 5 - LED lamp.

In FIG. 6 - LED lamp with two caps.

Terms and Definitions:

- rigidity means the ability of a material to resist deformation under external influence;

- the elasticity of the hardened compound implies its ability to restore size and shape after deformation;

- LED light source means a light source with one or more LEDs mounted on one board, substrate.

Obtaining a technical result in terms of reliability, impact resistance and resistance to destructive loads of LED devices designed using the claimed method is based on the properties of a flexible shell of a rigid material with a filler from a hardened elastic compound to maintain the volume and shape of the formed shell of the camera. Conservation of volume occurs due to the fact that the rigid shell does not stretch, and the hardened elastic compound practically does not compress. A rigid shell filled with a hardened elastic compound reacts elastically to shock, like a closed plastic water bottle. In addition, the hardened elastic compound retains its original shape and restores it in case of deformation. The decrease in the cost of lighting devices is associated with the low cost of the shell and compound. The shell is made by vacuum molding, which uses inexpensive aluminum or wood matrixes.

A second invention of the group, an LED lamp, is illustrated in FIG. 1. LED light source pos. 1, with LEDs pos. 10 is mounted on a heat-conducting casing pos. 2. The LED light source is covered with a flexible light-transmitting sheath pos. 3 (shown in section), the cavity between the LED light source and the flexible light-transmitting sheath is filled with light-transmitting hardened elastic compound pos. 4, (shown in section).

The technical result according to the second invention of the group, an LED lamp, is to increase the reliability and resistance to destructive loads, obtained by using a light transmitting shell from a hard thermodeformable material and a hardened compound underneath as a light transmission cover of the lamp. The shell protects the lamp from the penetration of foreign objects, the compound from shock, squeezing. The claimed technical result, cost reduction, is obtained due to the low cost of manufacturing the shell and low cost of the compound. The increase in efficiency is achieved through the use of a heat-conducting compound, which leads to additional cooling of the LEDs, the effectiveness of which is inversely dependent on the operating temperature.

FIG. 2 illustrates LED fixtures manufactured using the second group invention. On the left is a luminaire with the addition of scattering pigment to the compound. The power of the luminaires is 17.5 W, the luminous flux of 1400 lumens, dimensions 100 × 120 mm. The luminaires use LED light sources with a built-in driver SMJD-3V16W1P3. The heat sinks of the luminaires are 3 mm thick aluminum plates. Light-transmitting covers are made in the form of a flexible light-transmitting shell obtained by vacuum molding from polyethylene terephthalate (PET, softening temperature 260 ° C) with a thickness of 0.35 mm. The diameter of the light-transmitting window of the fixtures is 100 mm. The cavities under the shell are filled with transparent Silagerm 2206 silicone with a thermal conductivity of 0.4 W / (m⋅K), a hardness of 40 (Shore) and a working temperature after hardening of -60 ° C + 250 ° C. For uniformity of radiation from the entire surface of the exit window, a scattering white pigment is added to the silicone of the left lamp. The height of the cavity filled with silicone in each lamp is from 4.5 to 6.5 mm. Thermal relays with a cut-off temperature of 95 ° C in the form of thermal contacts KSD-9700M-95-NC are installed under the shells. Lamps withstand hammer blows, loads of 100 kg, absolutely tight.

The scattering white pigment used in one of the fixtures partially absorbs the luminous flux from the LED light source. To diffuse the luminous flux of the lamp, it is possible to use a scattering relief on the surface of a flexible light-transmitting shell. The relief of the shell can be made in the form of one or more lenses to form a curve of the light intensity of the lamp. In the luminaire, LEDs with blue light emission and a remote phosphor emitting additional colors under the influence of blue radiation can be used. The distant phosphor can be applied to a light-transmitting shell or evenly mixed in a transparent compound.

An LED driver can be installed in the cavity between the LED light source mounted on the heat-conducting body and the light-transmitting lid filled with the light-transmitting hardening compound.

If the heat exchange is disturbed, the heat generated by the LEDs and the lamp driver can lead to an increase in the temperature of the lamp and to its malfunction. To prevent such situations, a thermal relay with a shutdown temperature corresponding to the maximum temperature of the luminaire elements can be placed in the cavity filled with the compound. Thermal relay in the form of thermal contacts KSD-9700M-95-NC installed in the luminaires illustrated in FIG. 2, have low cost and high.

The group's third invention, an LED lamp, is illustrated in FIG. 3. In FIG. 3 poses 1 - LED light sources, pos. 10 - LEDs, pos. 3 - flexible light-transmitting shell, pos. 4 light transmitting hardened elastic compound, pos. 5 - driver, pos. 6 - thermal relay, pos. 7 - holder, pos. 8 - base. Unlike the prototype, the lamp has a flexible light-transmitting shell, the heat released by the LEDs is removed due to heat fluxes in the hardened light-transmitting compound.

The technical result - high reliability, strength, low cost, is achieved similarly to the second invention of the group through the use of a flexible light-transmitting shell filled with hardened elastic compound. Improving the lamp efficiency is achieved by improving the cooling of the LEDs and the driver through the use of a heat-conducting substance with a large coefficient of thermal conductivity. The thermal conductivity coefficient used in the prototype for heat removal of gases (hydrogen and / or helium) at the operating temperatures of the LEDs does not exceed 0.2 W / (m⋅K). Gravity convection, as specified in the description of the prototype, does not significantly affect the cooling of the lamp due to the small volume of the bulb. The compound used to remove heat has a thermal conductivity higher than the thermal conductivity of gases. For example, Silagerm 2206 transparent hardening silicone has a thermal conductivity of 0.4 W / (m⋅K). The thermal conductivity of the compound is increased by introducing heat-conducting transparent additives, for example glass beads.

The temperature of the LED light sources of the lamp depends on the temperature of the shell, the length of the heat path from the light source to the shell, the heat-conducting cross sections of the heat fluxes and the thermal conductivity of the material of the heat conduit - compound and is expressed by the well-known Fourier heat equation

where ΔТ is the temperature difference between the temperature of the light source and the lamp shell, P is the heat flux power, L is the heat path length, k is the compound's thermal conductivity coefficient, S is the area of the heat-conducting cross section of the heat flux.

The temperature of the lamp shell is inversely proportional to its area with which heat is dissipated into the surrounding air due to convection and radiation. An increase in the sheath area can lead to an increase in the volume of the lamp and, accordingly, to an excessive increase in its weight, which is associated with the density of the compound filling it. The manufacture of a shell from a rigid thermally deformable material allows to give it any shape without technological costs, for example, as in FIG. 4. The depressions of .9 in FIG. 4 can reduce the volume and accordingly the weight of the lamp while maintaining or increasing the area of the casing. In addition, the location of the LED source in the protrusion of the lamp shell leads to a reduction in the heat path L and an increase in the area of the heat-conducting cross section of the heat flux S (heat equation) and thus lowering the temperature of the LED light sources.

The area of the heat-conducting cross section of the heat flux S is determined by the areas of the heat-conducting cross sections through which the heat flux is directed, including the surface area of the bulb with which heat is dissipated and the surface area of the LED light source from which heat is removed. In general, such an area is defined as:

where F (x) is the function of the cross section of the variable body, L is the heat path length (Garwin's theorem). Thus, an increase in the area of the heat-conducting section of the heat flux S in the lamp is possible by increasing the area of the LED light source, for example, by increasing the area of the heat-conducting board on which the LEDs are mounted.

Unlike the prototype, the lamp may not have a holder for LED light sources - the compound will hold them after hardening. The hardened compound can act as a diffuser; for this, it is necessary to mix diffusing pigment or hollow glass microspheres into it. The lamp can be used with blue light emitting diodes and a remote phosphor emitting additional colors under the influence of blue light. The distant phosphor can be applied to a light-transmitting shell or evenly mixed in a transparent compound.

The practical implementation of the LED lamp is illustrated in FIG. four.

The bulb of the lamp illustrated in FIG. 4 is made of components that were used in the implementation of the LED lamp illustrated in FIG. 2. LED light sources of the lamp are made in the form of filaments - LED filaments, which are a glass or sapphire substrate, on which there are many LEDs coated with a common phosphor. By using two plinths, it is possible to make the lamp illustrated in FIG. 6.

Claims (6)

1. A method of constructing a lighting device in which at least one LED light source is protected by a light-transmitting cover, and the cavity between the LED light source and the light-transmitting cover is filled with a light-transmitting hardening compound, characterized in that a flexible light-transmitting shell of rigid material is used as a light-transmitting cover, and the cavity between the LED light source and the flexible light transmitting sheath is filled with light transmitting hardening to elastic mound after hardening. 2. LED lamp, consisting of an LED light source mounted on a heat-conducting body, a light-transmitting cover installed above the LED light source, a light-transmitting hardening compound filling the cavity between the LED light source mounted on the heat-conducting body and the light-transmitting cover, characterized in that the light-transmitting cover is made in the form of a flexible light-transmitting shell of hard thermo-deformable material, and light-transmitting hardened yuschy compound is formed as a light-transmitting elastic after hardening solidifying compound. 3. The LED lamp according to claim 2, characterized in that the LED light source consists of several LEDs. 4. The LED lamp according to claim 2, characterized in that the flexible light-transmitting shell of hard thermo-deformable material has the shape of one or more lenses, which, in combination with the light-transmitting hardening compound, after hardening, have optical properties that form the direction of the light flux from the LED light source. 5. The LED lamp according to claim 2, characterized in that the LED driver is installed in the cavity between the LED light source and the flexible light-transmitting shell of a rigid thermally deformable material filled with a light-transmitting hardening compound. 6. The LED lamp according to claim 2, characterized in that in the cavity between the LED light source mounted on the heat-conducting casing and a flexible light-transmitting shell of hard thermo-deformable material filled with light-transmitting hardening compound, a thermal relay is installed with a shutdown temperature below the maximum operating temperature of the LED light source.

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