Fog lampshade structure

Abstract

The utility model discloses a fog lamp shade structure, including outer layer transparent shade, inner layer light diffusion layer and antifogging layer, the bottom of outer layer transparent shade is provided with a plurality of air inlet, install first filter screen in the air inlet, the top of outer layer transparent shade is provided with a plurality of air outlet, and the air outlet and air inlet both have one-to-one correspondence. Through the unique air inlet and outlet design that the air inlet is formed in the bottom of the outer-layer transparent cover, the first filter screen is installed, the one-way ventilation mechanism is arranged in the air outlet, and the second filter screen is installed on the top of the shell, the air filtering capacity is greatly improved, corrosion of impurities to the fog lamp is reduced, and the service life is prolonged; mist accumulation is reduced through natural convection of the bottom air inlet hole and the top air outlet hole, the heating element embedded into the inner side edge of the outer-layer transparent cover is matched to eliminate mist when the mist is generated, the transparency of the lampshade is ensured, the lighting effect of the fog lamp in a complex environment is guaranteed, and the driving safety of a vehicle is improved.

Description

Technical Field

[0001] This utility model relates to the field of automotive parts technology, and in particular to a fog light cover structure. Background Technology

[0002] Existing fog light cover structures generally suffer from several issues affecting fog light performance and lifespan. On one hand, fog accumulation is a significant problem. In environments with high humidity or large temperature fluctuations, fog easily forms inside the fog light cover. This fog severely reduces the cover's transparency, thus affecting the fog light's illumination and posing a potential threat to vehicle safety. On the other hand, dust, small particles, and foreign objects in the air can easily enter the cover. These impurities not only adhere to the fog light components, accelerating wear and tear, but may also affect the fog light's normal operation and reduce its lifespan.

[0003] Therefore, we propose a fog light cover structure. Utility Model Content

[0004] The main purpose of this utility model is to provide a fog light cover structure to prevent fog accumulation from affecting the fog light's illumination effect and to prevent dust and impurities from entering the cover and accelerating component wear, thus affecting the fog light's normal illumination and lifespan. This effectively solves the problems in the background art and improves the performance and lifespan of the fog light.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A fog light cover structure includes an outer transparent cover, an inner light diffusion layer, and an anti-fog layer. The bottom of the outer transparent cover is provided with multiple air inlets, and a first filter screen is installed in each air inlet. The top of the outer transparent cover is provided with multiple air outlets, and the number of air outlets corresponds one-to-one with the number of air inlets.

[0007] Each of the air outlets is equipped with a one-way ventilation mechanism, which includes a housing and a diaphragm. The housing has multiple ventilation holes that communicate with the air outlets. The diaphragm is fixed to the housing and covers and seals the multiple ventilation holes. A second filter screen is installed on the top of the housing. Heating elements are evenly embedded in the inner edge of the outer transparent cover.

[0008] By adopting the above technical solution, when the internal temperature or air pressure of the lamp cover decreases, external air enters the outer transparent cover through the bottom air inlet under the action of air pressure difference. The first filter screen inside the air inlet plays a preliminary filtering role, which can intercept dust, small particulate impurities and foreign objects in the air, preventing them from entering the inside of the lamp cover and protecting the fog light components;

[0009] When the temperature or air pressure inside the lampshade increases, the internal air pressure becomes higher than the external air pressure. At this time, the air pressure acts on the diaphragm of the one-way ventilation mechanism. The diaphragm deforms under the pressure, causing the vents inside the housing to open. The internal air is then discharged to the outside of the lampshade through the vents and outlets. The second filter at the top of the housing not only filters the discharged air again, intercepting tiny particles that may affect the appearance of the lamp or the surrounding environment, but also prevents dust and other impurities from entering the lampshade. When the internal air pressure of the lampshade decreases, the diaphragm returns to its original shape under its own elasticity and the external air pressure, resealing the vents and preventing external air from entering, thus achieving one-way ventilation.

[0010] According to the principle of thermal expansion and contraction, hot air will rise and be discharged from the top of the vent, while cooler air from the outside will enter from the bottom air inlet, forming natural convection. This natural convection can carry out the humid air inside the lampshade, reduce the relative humidity of the internal air, and thus prevent fog from accumulating.

[0011] During the use of the lampshade, especially in environments with high humidity or large temperature fluctuations, fog is easily generated. When fog occurs, the heating element embedded in the inner edge of the outer transparent cover starts to work. The heating element converts electrical energy into heat energy, raising the temperature of the inner layer of the lampshade. For the fog that has already formed, which is the small water droplets on the surface of the inner layer of the lampshade, the heat generated by the heating element is transferred to these small water droplets. After absorbing the heat, the temperature of the small water droplets rises, and they evaporate again into water vapor, thus effectively preventing fog from accumulating in the inner layer of the lampshade and ensuring the transparency of the lampshade and the lighting effect of the fog light.

[0012] Furthermore, the inner light diffusion layer is disposed inside the outer transparent cover, and the anti-fog layer is disposed inside the inner light diffusion layer.

[0013] By adopting the above technical solution, the inner light diffusion layer is used to refract and scatter the light emitted by the fog lamp, so that the light is evenly distributed and the illumination range and uniformity are increased.

[0014] The function of the anti-fog layer is to prevent water vapor from condensing into fog on the inner surface of the lampshade or to allow water vapor to exist in a way that does not affect the propagation of light, so that light can pass through the lampshade smoothly.

[0015] Furthermore, the inner light diffusion layer is composed of a microprism array, and the anti-fog layer is made of a hydrophilic polymer material.

[0016] By adopting the above technical solution, these microprism arrays will cause light to refract and scatter. When the light passes through the light diffusion layer, it does not travel in a straight line, but is dispersed in multiple directions. Through this refraction and scattering effect, the fog light, which may have been relatively concentrated, is evenly dispersed to a larger angular range. This can increase the coverage area of ​​the fog light illumination, so that the sides of the road in front of the vehicle and the nearby area can receive more uniform illumination, reducing the "dark areas" of illumination, thereby improving the driver's ability to observe the surrounding road conditions in low visibility environments such as fog.

[0017] The hydrophilic anti-fog layer allows water vapor to spread evenly on its surface, forming a thin water film rather than small water droplets. This is because the hydrophilic material molecules and water molecules have a strong mutual attraction, allowing water vapor to spread rapidly on its surface. As a result, when light passes through this water film, the effects of scattering and refraction are relatively small, and it does not seriously interfere with the propagation of light like small water droplets, thus maintaining good transparency.

[0018] Furthermore, the diaphragm is an umbrella-shaped diaphragm, consisting of an umbrella cover and an umbrella handle. The umbrella cover covers multiple ventilation holes, and the umbrella handle is fixed to the outer shell.

[0019] By adopting the above technical solution, when the air pressure inside the fog light cover is higher than the outside air pressure, the pressure generated by the internal air acts on the umbrella-shaped diaphragm cover. Since the cover is movable, it will lift up under the pressure, opening the multiple vents that were originally closed. At this time, the air inside the cover can be discharged to the outside of the lamp cover through the vents and outlets. When the air pressure inside the fog light cover decreases, is lower than the outside air pressure or is in balance with the outside air pressure, the cover will move down along the handle under its own weight and the outside air pressure, covering the multiple vents again and sealing them, preventing outside air from entering the lamp cover, thus realizing unidirectional gas flow.

[0020] Furthermore, the diaphragm is made of a flexible material.

[0021] By adopting the above technical solution, when the air pressure inside the lampshade is higher than the air pressure outside, the pressure generated by the internal air will act on the diaphragm. Since the diaphragm is made of flexible silicone, it can deform under pressure. Its molecular structure allows it to change shape under force without breaking. This deformation pushes open the diaphragm part that originally closed the vent, thereby opening the ventilation channel. Air can then be discharged from inside the lampshade to the outside of the lampshade through the vent and exhaust holes, thus achieving the regulation of the air pressure inside the lampshade.

[0022] When the air pressure inside the lampshade decreases to be equal to or lower than the external air pressure, the external air pressure will exert pressure on the diaphragm. At the same time, the silicone itself has elastic recovery force. The combined effect of these two forces causes the diaphragm to return to its original shape. The diaphragm then covers and seals the vent, preventing external air from entering the lampshade. This use of the elasticity and deformation characteristics of flexible materials ensures that the one-way ventilation mechanism can effectively achieve the one-way ventilation function and maintain the stability of the internal environment of the lampshade.

[0023] Furthermore, the heating element is a resistance wire.

[0024] By employing the above technical solution, when it is necessary to prevent fog from forming inside the lampshade or to dissipate existing fog, current flows through the resistance wire heating element. According to Joule's law, heat is generated when current passes through a resistive conductor wire. This heat is transferred to the surrounding air and the inner surface of the lampshade through thermal conduction. Because the interior space of the lampshade is relatively enclosed, the heat gradually diffuses within this space. When there are small water droplets of fog inside the lampshade, these droplets absorb the heat transferred from the resistance wire, causing their temperature to rise. When the temperature of the water droplets reaches their boiling point, they will re-evaporate into water vapor, thus dissipating the fog. Simultaneously, even without fog, the increased temperature of the heated inner layer of the lampshade prevents water vapor in the surrounding air from condensing and forming fog on the cooler inner surface of the lampshade, ensuring the transparency of the lampshade.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention provides a fog light cover structure, which greatly improves the air filtration capacity through a unique air intake and exhaust design. Multiple air intake holes are set at the bottom of the outer transparent cover, and a first filter screen is installed in the air intake hole. When the air enters the inside of the cover, it can effectively intercept dust, small particulate impurities and foreign objects in the air, providing a first layer of protection for the fog light components. In the one-way ventilation mechanism set in the exhaust hole, a second filter screen installed on the top of the outer shell not only filters the exhaust air again to prevent the small particles brought out from the inside of the cover from affecting the appearance of the lamp or the surrounding environment, but also blocks dust and other impurities from entering the cover in reverse. This dual filtration mechanism greatly reduces the erosion of the fog light by impurities, extends the service life of the fog light, and ensures the long-term stable working performance of the fog light.

[0027] (2) This utility model provides a fog light cover structure that utilizes the principle of thermal expansion and contraction and a heating element to achieve a highly efficient anti-fog function. When the temperature or air pressure inside the cover changes, the natural convection formed by the bottom air inlet and the top air outlet can carry out the humid air inside the cover, reducing the relative humidity of the internal air and reducing the possibility of fog accumulation from the source. When fog has already formed, the heating element embedded in the inner edge of the outer transparent cover begins to play its role. The heating element converts electrical energy into heat energy, raising the temperature of the inner layer of the cover. The small water droplets of fog that have formed absorb the heat and then evaporate back into water vapor, thereby quickly and effectively eliminating fog and ensuring that the cover always maintains good transparency. This ensures that the fog light can provide clear and stable lighting effects in various complex environments, effectively improving the safety of vehicle driving. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of a fog light cover structure according to the present invention.

[0029] Figure 2 This is a schematic diagram of the internal structure of a fog light cover structure according to the present invention.

[0030] Figure 3 This utility model relates to a fog light cover structure. Figure 2 Enlarged view of point A in the middle.

[0031] Figure 4 This is a partial cross-sectional view of a fog light cover structure according to the present invention.

[0032] In the diagram: 1. Outer transparent cover; 2. Air inlet; 3. First filter; 4. Air outlet; 5. Outer shell; 6. Diaphragm; 7. Ventilation hole; 8. Umbrella cover; 9. Umbrella handle; 10. Second filter; 11. One-way ventilation mechanism; 12. Heating element; 13. Inner light diffusion layer; 14. Anti-fog layer. Detailed Implementation

[0033] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0034] To prevent fog buildup from affecting the lighting effect of fog lights and to prevent dust and impurities from entering the lamp cover and accelerating component wear, thus affecting the normal operation and lifespan of fog lights, and thereby improving the performance and lifespan of fog lights, such as... Figure 1 , Figure 2 , Figure 3 , Figure 4As shown, a fog light cover structure includes an outer transparent cover 1, an inner light diffusion layer 13, and an anti-fog layer 14. The bottom of the outer transparent cover 1 is provided with multiple air inlets 2, and a first filter screen 3 is installed in the air inlets 2. The top of the outer transparent cover 1 is provided with multiple air outlets 4, and the number of air outlets 4 corresponds one-to-one with the number of air inlets 2.

[0035] Each of the air outlets 4 is provided with a one-way ventilation mechanism 11. The one-way ventilation mechanism 11 includes a housing 5 and a diaphragm 6. The housing 5 has multiple ventilation holes 7 that communicate with the air outlets 4. The diaphragm 6 is fixed on the housing 5 and covers and seals the multiple ventilation holes 7. A second filter screen 10 is installed on the top of the housing 5. Heating elements 12 are evenly embedded in the inner edge of the outer transparent cover 1.

[0036] When in use, when the temperature inside the lamp cover decreases or the air pressure drops, outside air enters the outer transparent cover 1 through the bottom air inlet 2 under the action of the air pressure difference. The first filter 3 inside the air inlet 2 plays a preliminary filtering role, which can intercept dust, small particulate impurities and foreign objects in the air, prevent them from entering the lamp cover and protect the fog light components;

[0037] When the temperature or air pressure inside the lampshade increases, the internal air pressure is higher than the external air pressure. At this time, the air pressure acts on the diaphragm 6 of the one-way ventilation mechanism 11. The diaphragm 6 deforms under the pressure, causing the vent 7 inside the outer shell 5 to open. The internal air is discharged to the outside of the lampshade through the vent 7 and the air outlet 4. The second filter 10 at the top of the outer shell 5 not only filters the discharged air again, intercepting tiny particles that may affect the appearance of the lamp or the surrounding environment brought out from inside the lampshade, but also prevents dust and other impurities from entering the lampshade. When the air pressure inside the lampshade decreases, the diaphragm 6 returns to its original shape under its own elasticity and the action of external air pressure, re-closing the vent 7 and preventing external air from entering, thereby achieving one-way ventilation.

[0038] According to the principle of thermal expansion and contraction, hot air will rise and be discharged from the top of the vent 7, while the cooler air outside will enter from the bottom air inlet 2, forming natural convection. This natural convection can carry out the humid air inside the lampshade, reduce the relative humidity of the internal air, and thus prevent fog from accumulating.

[0039] During the use of the lampshade, especially in environments with high humidity or large temperature fluctuations, fog is easily generated. When fog occurs, the heating element 12 embedded in the inner edge of the outer transparent cover 1 starts to work. The heating element 12 converts electrical energy into heat energy, raising the temperature of the inner layer of the lampshade. For the fog that has already formed, i.e., the small water droplets on the surface of the inner layer of the lampshade, the heat generated by the heating element 12 will be transferred to these small water droplets. After absorbing the heat, the temperature of the small water droplets rises, and they evaporate again into water vapor, thereby effectively preventing fog from accumulating in the inner layer of the lampshade and ensuring the transparency of the lampshade and the lighting effect of the fog light.

[0040] For example, such as Figure 4 As shown, the present invention also includes an inner light diffusion layer 13 disposed inside the outer transparent cover 1, and an anti-fog layer 14 disposed inside the inner light diffusion layer 13.

[0041] When in use, the inner light diffusion layer 13 is used to refract and scatter the light emitted by the fog lamp, so that the light is evenly distributed and the illumination range and uniformity are increased;

[0042] The function of the anti-fog layer 14 is to prevent water vapor from condensing into fog on the inner surface of the lampshade or to allow water vapor to exist in a way that does not affect the propagation of light, so that light can pass through the lampshade smoothly.

[0043] For example, such as Figure 4 As shown, the present invention also includes an inner light diffusion layer 13 composed of a microprism array and an anti-fog layer 14 made of a hydrophilic polymer material.

[0044] When in use, these microprism arrays refract and scatter light. When light passes through the light diffusion layer, it does not travel in a straight line, but is dispersed in multiple directions. Through this refraction and scattering effect, the fog light, which may have been relatively concentrated, is evenly dispersed to a larger angular range. This increases the coverage area of ​​the fog light illumination, so that the sides of the road in front of the vehicle and the nearby area can receive more uniform illumination, reducing the "dark areas" of illumination, thereby improving the driver's ability to observe the surrounding road conditions in low visibility environments such as fog.

[0045] The hydrophilic anti-fog layer allows water vapor to spread evenly on its surface, forming a thin water film rather than small water droplets. This is because the hydrophilic material molecules and water molecules have a strong mutual attraction, allowing water vapor to spread rapidly on its surface. As a result, when light passes through this water film, the effects of scattering and refraction are relatively small, and it does not seriously interfere with the propagation of light like small water droplets, thus maintaining good transparency.

[0046] For example, such as Figure 2 , Figure 3As shown, the present invention also includes an umbrella-shaped diaphragm 6, which is composed of an umbrella cover 8 and an umbrella handle 9. The umbrella cover 8 covers a plurality of ventilation holes 7, and the umbrella handle 9 is fixed to the outer shell 5.

[0047] When in use, when the air pressure inside the fog light cover is higher than the outside air pressure, the pressure generated by the internal air acts on the umbrella-shaped diaphragm cover 8. Since the umbrella cover 8 is movable, it will lift up under the pressure, opening the multiple vent holes 7 that were originally closed. At this time, the air inside the cover can be discharged to the outside of the lamp cover through the vent holes 7 and the air outlet 4. When the air pressure inside the fog light cover decreases, is lower than the outside air pressure or is in balance with the outside air pressure, the umbrella cover 8 will move down along the handle 9 under its own weight and the outside air pressure, covering the multiple vent holes 7 again and closing the vent holes 7, preventing outside air from entering the lamp cover, thus realizing the unidirectional flow of gas.

[0048] For example, such as Figure 2 , Figure 3 As shown, the present invention also includes a diaphragm 6 made of a flexible material.

[0049] When in use, when the air pressure inside the lampshade is higher than the air pressure outside, the pressure generated by the internal air will act on the diaphragm 6. Since the diaphragm 6 is made of flexible silicone, it can deform under pressure. Its molecular structure allows it to change shape under force without breaking. This deformation pushes open the diaphragm part that originally closed the vent 7, thereby opening the ventilation channel. Air can then be discharged from inside the lampshade through the vent 7 and the air outlet 4 to the outside of the lampshade, thus regulating the air pressure inside the lampshade.

[0050] When the air pressure inside the lampshade decreases to be equal to or lower than the external air pressure, the external air pressure will exert pressure on the diaphragm 6. At the same time, the silicone itself has elastic recovery force. The two forces work together to make the diaphragm 6 return to its original shape. The diaphragm 6 covers and seals the vent 7 again, preventing external air from entering the lampshade. This use of the elasticity and deformation characteristics of flexible materials ensures that the one-way ventilation mechanism 11 can effectively realize the one-way ventilation function and maintain the stability of the internal environment of the lampshade.

[0051] For example, such as Figure 2 , Figure 3 As shown, the present invention also includes a heating element 12, which is a resistance wire.

[0052] In use, when it is necessary to prevent fog from forming inside the lampshade or to dissipate existing fog, current flows through the resistance wire heating element 12. According to Joule's law, heat is generated when current passes through a resistive conductor wire. This heat is transferred to the surrounding air and the inner surface of the lampshade through thermal conduction. Because the interior space of the lampshade is relatively enclosed, the heat gradually diffuses within this space. When there are small water droplets of fog inside the lampshade, these droplets absorb the heat transferred from the resistance wire, causing their temperature to rise. When the temperature of the water droplets reaches their boiling point, they will re-evaporate into water vapor, thus dissipating the fog. At the same time, even without fog, the increased temperature of the heated inner layer of the lampshade prevents water vapor in the surrounding air from condensing and forming fog on the cooler inner surface of the lampshade, ensuring the transparency of the lampshade.

[0053] It should be noted that this utility model is a fog light cover structure. When the vehicle is started and the fog light cover is in normal working condition, there is an air pressure difference between the inside of the cover and the external environment. If the temperature or air pressure inside the cover decreases, external air will automatically enter the outer transparent cover 1 from the bottom air intake 2 under the action of the air pressure difference. During the air intake process, the first filter 3 inside the air intake 2 performs preliminary filtration of the air, blocking dust, small particulate impurities and foreign objects from entering the inside of the cover. As the vehicle moves, if the temperature or air pressure inside the cover increases, the internal air pressure will be higher than the external air pressure. The diaphragm 6 acting on the one-way ventilation mechanism 11 deforms under pressure, opening the vent 7 inside the housing 5. At this time, the internal air is discharged outside the lampshade through the vent 7 and the air outlet 4. During the discharge process, the second filter 10 at the top of the housing 5 filters the discharged air again, intercepting the tiny particles brought out from inside the lampshade and preventing external dust from entering. When the air pressure inside the lampshade decreases, the diaphragm 6 returns to its original shape under its own elasticity and external air pressure, closing the vent 7 and preventing external air from entering, thus continuously ensuring one-way ventilation and maintaining stable air pressure inside the lampshade.

[0054] In environments with high humidity or large temperature fluctuations, when fog appears inside the lamp cover, the vehicle's electrical system energizes the resistance wire heating element 12 embedded in the inner edge of the outer transparent cover 1. The current passes through the resistance wire, generating heat according to Joule's law. The heat is transferred to the surrounding air and the inner surface of the lamp cover through thermal conduction, raising the temperature of the inner layer of the lamp cover. The small water droplets of fog that have formed inside the lamp cover absorb the heat and their temperature rises, causing them to evaporate again into water vapor, thereby dissipating the fog. At the same time, the higher temperature of the inner layer of the lamp cover can prevent water vapor in the surrounding air from condensing on the surface of the inner layer of the lamp cover when it cools down, thus maintaining the transparency of the lamp cover.

[0055] When the fog lights are turned on, the light shines into the inner light diffusion layer 13 located inside the outer transparent cover 1. The inner light diffusion layer 13, composed of a microprism array, refracts and scatters the light, dispersing the originally concentrated fog light evenly over a wider angle range, increasing the fog light illumination coverage area, and providing more uniform illumination to the sides of the road and nearby areas in front of the vehicle. This reduces "dark areas" and improves the driver's ability to observe road conditions in low visibility environments such as fog. The anti-fog layer 14, made of hydrophilic polymer material, located inside the inner light diffusion layer 13, utilizes the strong attraction between hydrophilic material molecules and water molecules to allow water vapor to spread evenly on its surface to form a thin water film, rather than small water droplets. This reduces interference caused by the scattering and refraction of light droplets when it passes through, ensuring that the light passes smoothly through the lamp cover and maintains good lighting performance.

[0056] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A fog light cover structure, comprising an outer transparent cover (1), an inner light diffusion layer (13), and an anti-fog layer (14), characterized in that, The bottom of the outer transparent cover (1) is provided with multiple air inlets (2), and a first filter screen (3) is installed inside the air inlets (2). The top of the outer transparent cover (1) is provided with multiple air outlets (4), and the number of air outlets (4) corresponds one-to-one with the number of air inlets (2). Each of the air outlets (4) is provided with a one-way ventilation mechanism (11). The one-way ventilation mechanism (11) includes a shell (5) and a diaphragm (6). The shell (5) has multiple ventilation holes (7) that communicate with the air outlets (4). The diaphragm (6) is fixed on the shell (5) and covers the multiple ventilation holes (7) and seals them. A second filter screen (10) is installed on the top of the shell (5). Heating elements (12) are evenly embedded at the inner edge of the outer transparent cover (1).

2. The fog light cover structure according to claim 1, characterized in that: The inner light diffusion layer (13) is disposed inside the outer transparent cover (1), and the anti-fog layer (14) is disposed inside the inner light diffusion layer (13).

3. A fog light cover structure according to claim 1, characterized in that: The inner light diffusion layer (13) is composed of a microprism array, and the anti-fog layer (14) is made of a hydrophilic polymer material.

4. A fog light cover structure according to claim 1, characterized in that: The diaphragm (6) is an umbrella-shaped diaphragm and consists of an umbrella cover (8) and an umbrella handle (9). The umbrella cover (8) covers a plurality of ventilation holes (7), and the umbrella handle (9) is fixed to the outer shell (5).

5. A fog light cover structure according to claim 1, characterized in that: The diaphragm (6) is made of a flexible material.

6. A fog light cover structure according to claim 1, characterized in that: The heating element (12) is a resistance wire.

Images