Elastic mounting structure of heating film and far infrared energy generator

Abstract

The invention discloses an elastic mounting structure of a heating film and a far infrared energy generator, the elastic mounting structure comprises an insulating film body, a heating element is arranged in the insulating film body, the area between the heating element and the edge of the insulating film body is a non-heating area, two corresponding non-heating areas are set as fixing parts, and the fixing parts are fixed on the insulating film body. The other two corresponding non-heating areas are arranged to be adjacent parts, the fixing parts and the elastic connecting pieces are fixed in a pre-tensioning mode, and the width size of the adjacent parts is smaller than or equal to 5 mm. According to the invention, the surface temperature field of the heating film can be ensured to be consistent to the greatest extent, so that the surface flatness at normal temperature and in a thermal state is ensured, and the assembly difficulty and cost are reduced.

Description

Technical Field

[0001] This invention relates to the engineering application of flexible polymer heating films, specifically to an elastic mounting structure for a heating film and a far-infrared energy generator. Background Technology

[0002] Flexible heating films are composed of a relatively thin insulating film and a heating element (heating film layer), with a thickness of approximately 0.1 mm. They are soft in texture and can be rolled up. (See reference) Figure 1 As shown, the heating element is the middle diagonal section, and the left and right sides of the heating element are electrodes. Insulating films are set on the front and back of the heating element to cover the heating element and electrodes together. Thus, from the perspective of the flexible heating film as a whole, the heating element part heats up directly and is the heating area, while the surrounding part needs to be heated by the heating element and then heat conducted up, which is the non-heating area.

[0003] Typically, the aforementioned flexible heating film is installed in a fixed manner to ensure its flatness after installation (unevenness can easily cause localized overheating of the heating film, thus affecting its lifespan). When powered on, its temperature reaches approximately 300℃. The heating element heats up as a whole, while the portion of the insulating film that covers and adheres to the heating element heats up synchronously. However, the portion not covered by the heating element cannot heat up synchronously (its temperature rise relies on lateral or convective heat transfer). This results in inconsistent temperatures between the heating and non-heating areas of the insulating film, causing the flat heating film to warp due to asynchronous thermal expansion. For the heating film, heat transfer primarily relies on far-infrared radiation (accounting for >90%). Only a uniform temperature field, without any hot spots, can guarantee the lifespan of the heating film. Warping of the film severely affects radiative heat transfer, creating localized hot spots. Therefore, to avoid hot spots, the heating film must be perfectly flat.

[0004] In existing installation structures, fixing points are set on the non-heating area of ​​the flexible heating film, and it is fixed to the inner side of the frame by snap-fit ​​or screw fixing. Limiting structures are set at the front and rear of the heating film to ensure that the heating film has good flatness when it is working.

[0005] The aforementioned fixing method greatly increases the assembly complexity, and a fixing beam structure is also required inside the device. Since there is no adaptive pre-tension, the overall weight of the device is increased, and the problem of inconsistent thermal expansion cannot be eliminated. The temperature field of the heating film is not consistent, the temperature difference is too large, and some poor assembly may even generate hot spots, affecting the life of the heating film.

[0006] Therefore, a method of pre-tensioning and fixing with a tension spring was developed. This method provides a tensile force to the heating film, and through the interference of external force, pre-tensions and flattens the heating film at room temperature. During operation, the heating film remains flat due to the pre-tensioning effect when it expands due to heat (the pre-tension is greater than the thermal expansion). However, the temperature difference between the heating area and the non-heating edge of the heating film is significant during operation. Therefore, it is crucial to minimize the width of the non-heating area in the direction of no stress. This reduces the temperature difference between the heating and non-heating areas in the direction of no stress. A large temperature difference in the non-stressed direction can easily cause warping and unevenness in the heating film, affecting product quality, safety, and lifespan. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide an elastic mounting structure for a heating film and a far-infrared energy generator, which can maximize the uniformity of the surface temperature field of the heating film, thereby ensuring the surface flatness at both room temperature and hot conditions, and reducing assembly difficulty and cost.

[0008] To solve the above-mentioned technical problems, the present invention provides an elastic mounting structure for a heating film, including an insulating film body, a heating element disposed within the insulating film body, and a non-heating area between the heating element and the edge of the insulating film body. Two corresponding non-heating areas are configured as fixed parts, and two other corresponding non-heating areas are configured as adjacent parts. The fixed parts are pre-stretched and fixed with an elastic connector, and the width of the adjacent parts is less than or equal to 8 mm.

[0009] Furthermore, the heating element is provided with electrodes, which are arranged parallel to and adjacent to the fixing part.

[0010] Furthermore, the tensile elongation of the insulating film body after pre-stretching through the elastic connector is greater than the maximum thermal expansion of the heating film during operation, and the tensile elongation rate after pre-stretching is less than 3%; this is to facilitate the maintenance of the elasticity of the film material and the recovery of its dimensions during cooling after thermal expansion, and to avoid the film material from relaxing after long-term stress; specifically, the tensile elongation of the insulating film body after pre-stretching through the elastic connector is greater than the thermal expansion of the heating film when the temperature rises to 350°C (the thermal expansion rate of the heating film when operating at 300°C is 0.7%-1%).

[0011] Furthermore, the fixing part is provided with a reinforcing strip, and the reinforcing strip is provided with a connecting part, which is connected to one end of the elastic connector.

[0012] Furthermore, the other end of the elastic connector is fixedly connected to the device frame.

[0013] Furthermore, the other end of the elastic connector is connected to the longitudinal rod, and the longitudinal rod is provided with a plurality of transition blocks, which are fixedly connected to the device frame.

[0014] Furthermore, the adapter block is provided with a plug hole, the longitudinal rod passes through the plug hole, and a fixing screw is provided on the longitudinal rod for fixing one end of the elastic connector to the longitudinal rod.

[0015] Furthermore, the fixing part is provided with an edge banding, which covers the reinforcing strip and is fixed by adhesive bonding.

[0016] Furthermore, the width of the adjacent portion is less than or equal to 5 mm and greater than or equal to 3 mm.

[0017] A far-infrared energy generator employs the elastic mounting structure of the heating film described in any one of the above-mentioned methods, the far-infrared energy generator being used for heating or physiotherapy.

[0018] The beneficial effects of this invention are:

[0019] This invention employs uniaxial stretching to fix the heating film, without any fixing method in the other axis. By controlling the size of the non-heating area in the unstressed direction, the heating film can remain flat in both hot and cold states. The width control of the non-heating area in the unstressed direction greatly reduces the temperature difference between the non-heating and heating areas, thereby ensuring a uniform temperature field and avoiding overheating. Without overheating, the heating film is guaranteed to operate safely and have a long lifespan. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of an existing flexible heating film;

[0021] Figure 2 This is a schematic diagram of the flexible heating film structure of the present invention;

[0022] Figure 3 This is a schematic diagram of the flexible heating film of the present invention during assembly and use;

[0023] Figure 4 This is a partial structural schematic diagram of the pre-stretched installation of the flexible heating film of the present invention;

[0024] Figure 5 This is a thermal image of the non-heating area and the heating area when the width of the non-heating area is 16mm.

[0025] Figure 6 This is a thermal image of the non-heating area and the heating area when the width of the non-heating area is 3mm. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0027] Reference Figures 1 to 3 As shown, one embodiment of the elastic mounting structure of the heating film of the present invention includes an insulating film body 1. The insulating film body is generally a two-layer structure, and a heating element 2 is disposed inside the insulating film body. The heating element is hot-pressed and bonded in the middle. When the heating element is energized, it generates heat, and the surface temperature can reach about 300 degrees Celsius. The insulating film body needs to be heated by heat transfer from the heating element. Therefore, the part where the heating element and the insulating film body are attached can heat up or cool down simultaneously, with high heat conduction efficiency, which is the heating zone. The area between the heating element and the edge of the insulating film body is not in direct contact, and the temperature transfer rate is lower than that of the part in direct contact, which is defined as the non-heating zone. This forms a temperature field, and the part of the non-heating zone that is close to the heating zone heats up faster, while the part that is far from the heating zone heats up slower. This leads to warping and unevenness due to different thermal expansion (the deformation of the insulating film part far from the heating zone and the insulating film part that is close to the heating zone is inconsistent, and the greater the temperature difference, the greater the inconsistency).

[0028] Although external force can be used to straighten the warped parts, it is necessary to stretch them outwards simultaneously from all four sides (i.e., the four non-heating areas), which makes the structure complex and costly. Otherwise, the non-heating areas that are not stretched will warp, which will gradually affect the temperature of the heating element of the heating film after long-term use, eventually leading to the failure of the entire heating film or causing more serious safety accidents.

[0029] Based on this, the present invention sets two corresponding non-heating areas as fixed parts 3, and another two corresponding non-heating areas as adjacent parts 4. The fixed parts are pre-stretched and fixed to the elastic connector 5, and the width of the adjacent parts is less than or equal to 5mm. The fixed parts, after being pre-stretched by the elastic connector, form a taut and flattened state in the current direction, such as... Figure 1 As shown, the fixing part is located on the left and right sides of the heating film, that is, the heating film 111 is flattened in the horizontal direction. At the adjacent parts on the upper and lower sides, the size of the non-heating area is effectively reduced by limiting its dimensions. This significantly reduces the temperature difference between the insulating film parts far from and near the heating area. The smaller the temperature difference, the higher the uniformity of the temperature field, i.e., the better the deformation uniformity. This allows the adjacent parts to deform together with the heating area, solving the warping problem. Therefore, after pre-stretching and flattening in the left and right directions, no additional upper and lower tension force is needed at the adjacent parts to maintain flatness.

[0030] The size of the adjacent portion is preferably <5mm. This has the advantage that the entire heating film is basically in the temperature zone from top to bottom, expanding together when heated and contracting together when cooled. From the perspective of thermal expansion and contraction, the smaller the size of the upper and lower non-heating areas, the better. The adjacent portion can also be omitted. However, since the heating film in the heating area is an electric conductor, from the perspective of strong electrical safety, the larger this part is, the better. Based on repeated experiments, the edge size of the upper and lower non-heating areas is preferably <5mm, with the optimal value being 3mm. Under the premise of meeting safety specifications, the consistency of thermal expansion and contraction is the best.

[0031] Since the heating element needs to be powered by electrode 6 during use, and the setting of the electrode will also cause inconsistencies in the temperature field, the electrodes set on the two corresponding sides of the heating element are set in a position adjacent to the fixing part. Flatness is ensured here by stretching left and right.

[0032] The above-mentioned tensile elongation of the insulating film body (i.e. the heating film as a whole) after pre-stretching by the elastic connector is <3%. That is, the pre-stretch amount of the heating film needs to be greater than the expansion amount of the heating film when it is working and heating. This ensures that the heating film has sufficient tensile force to ensure the flatness of the heating film when it is hot, thereby ensuring the uniformity of the temperature field and ensuring the safe operation and long service life of the heating film.

[0033] For the fixing part, if the elastic connector is directly connected to the insulating film body on the non-heating area, the insulation film material and the limitations of the connection may easily lead to damage and failure. Therefore, a reinforcing strip is provided on the fixing part, and a connecting part is provided on the reinforcing strip, which is connected to one end of the elastic connector.

[0034] The elastic connector here can be a tension spring, and the connecting part 7 on the reinforcing strip can be a hole. The hole is set as the hanging point of the tension spring to bear the tension. The reinforcing strip is preferably made of a rigid plate with good rigidity and is preferably an insulating material, such as a high-temperature resistant PCB, with a thickness between 0.5-1.5mm.

[0035] Based on the above structure, the tension of the spring acts on the reinforcing strip, and then is transmitted from the reinforcing strip to the insulating film. During this process, it is necessary to ensure an effective connection between the reinforcing strip and the insulating film. Therefore, an edging 8 is provided on the fixing part (the edging and the heating film can be separate, but the optimal method is to integrate them). The edging covers the reinforcing strip and is fixed by adhesive. In the above design, there is not only adhesive force between the reinforcing strip and the fixing part, but also the force transmitted through the abutment force after the edging, thereby ensuring the effectiveness of the connection between the two. In addition to adhesive bonding, the reinforcing strip and the edging can also be reinforced by applying adhesive 9 at the edge of the edging.

[0036] The other end of the flexible connector can be connected to frame 10 (the skeleton of the heater or physiotherapy device), effectively optimizing the overall structure and reducing manufacturing costs. (Refer to...) Figure 4 As shown, the other end of the elastic connector can also be connected to the longitudinal rod 11. Several adapter blocks 12 are provided on the longitudinal rod. The adapter blocks are fixedly connected to the device frame, that is, connected to the frame through the adapter component. The adapter component has good versatility, which makes the device modular.

[0037] For the installation method, the adapter block is provided with a plug hole 13, through which the longitudinal rod passes. A fixing screw is provided on the longitudinal rod to fix one end of the elastic connector to the longitudinal rod, making assembly convenient and cost-effective. Alternatively, a hanging hole can be made on the longitudinal rod, and the hook at one end of the tension spring can be directly hooked into the hanging hole to achieve a pre-tensioning effect.

[0038] This application also discloses a far-infrared energy generator, which adopts the elastic mounting structure of the heating film described above, and the far-infrared energy generator is used for heating or physiotherapy.

[0039] Reference Figure 5 As shown, with Figure 1 The heating film structure shown was tested for operation. The temperature of the non-heating area was 16 mm. After the heating film stabilized, images were taken using a thermal imager. It was found that the temperature of the heating area was around 250 degrees Celsius, while the temperature of the non-heating area was only around 100 degrees Celsius, a temperature difference of 150 degrees Celsius. Figure 6 As shown, with Figure 2 The heating film structure shown in the image was tested for operation. The temperature of the non-heating area was 3 mm. After the heating film stabilized, a thermal imager was used to take pictures. It was found that the temperature of the heating area was about 235 degrees Celsius, while the temperature of the non-heating area was about 210 degrees Celsius. Therefore, the temperature difference was about 25 degrees Celsius, which greatly ensured the consistency of the temperature field and effectively reduced problems such as warping and delamination.

[0040] In summary, this application pre-stretches the non-heating area on the side with electrodes on both sides, flattening it with external force. Meanwhile, the non-heating areas on the top and bottom sides are minimized to ensure synchronized thermal expansion and contraction with the heating area. Combined with the lateral flattening force, this prevents warping in the top and bottom non-heating areas. Therefore, the entire structure only requires pre-stretching on both sides, significantly reducing the number of components, lowering costs, and simplifying assembly.

[0041] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. An elastic mounting structure for a heating film, characterized in that, The device includes an insulating film body, in which a heating element is disposed. The area between the heating element and the edge of the insulating film body is a non-heating area. Two corresponding non-heating areas are set as fixed parts, and two other corresponding non-heating areas are set as adjacent parts. The fixed parts are pre-stretched and fixed with an elastic connector. The width of the adjacent parts is less than or equal to 5 mm.

2. The elastic mounting structure of the heating film as described in claim 1, characterized in that, The heating element is provided with electrodes, which are arranged parallel to and adjacent to the fixing part.

3. The elastic mounting structure of the heating film as described in claim 1, characterized in that, The tensile elongation of the insulating film body after pre-stretching through the elastic connector is greater than the maximum thermal expansion of the heating film during operation, and the tensile elongation rate after pre-stretching is less than 3%.

4. The elastic mounting structure of the heating film as described in claim 1, characterized in that, The fixing part is provided with a reinforcing strip, and the reinforcing strip is provided with a connecting part, which is connected to one end of the elastic connector.

5. The elastic mounting structure of the heating film as described in claim 4, characterized in that, The other end of the elastic connector is fixedly connected to the device frame.

6. The elastic mounting structure of the heating film as described in claim 4, characterized in that, The other end of the elastic connector is connected to the longitudinal rod, and the longitudinal rod is provided with several transition blocks, which are fixedly connected to the device frame.

7. The elastic mounting structure of the heating film as described in claim 6, characterized in that, The adapter block is provided with a plug hole, and the longitudinal rod passes through the plug hole; The longitudinal rod is provided with fixing screws for fixing one end of the elastic connector to the longitudinal rod; Alternatively, the longitudinal bar may be provided with a hanging hole for hooking one end of the elastic connector onto the longitudinal bar.

8. The elastic mounting structure of the heating film as described in claim 1, characterized in that, The fixing part is provided with an edge banding, which covers the reinforcing strip and is fixed by adhesive bonding.

9. The elastic mounting structure of the heating film as described in claim 1, characterized in that, The width of the adjacent portion is less than or equal to 5 mm and greater than or equal to 1 mm.

10. A far-infrared energy generator, characterized in that, The far-infrared energy generator is used for heating or physiotherapy by employing the elastic installation structure of the heating film according to any one of claims 1-9.

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