Patent Application
20210040662
The present application generally relates to an electrical heating element, especially an apparatus for sewing an electrical heating element, for example an electrical heating metallic wire, used in a heating cushion of a vehicle. The present application also relates to a softening device, for softening the electrical heating element, used in the sewing apparatus, and a control method for controlling the device.
In producing a heating cushion of a vehicle, an electrical heating metallic wire is required to be sewn onto a carrier of the vehicle's cushion in a predefined pattern. The electrical heating metallic wire is usually coated with an insulating skin on its outer surface. In order to improve the heating performance of the vehicle's heating cushion, the electrical heating metallic wire may be sewn onto the carrier in a pattern of high density. The insulating skin is usually made of a relatively hard material, and may be multiple bent with relatively sharp angles on the carrier. In case that the pattern is very dense, the insulating skin of the electrical heating metallic wire may be broken due to being multiple bent, which thus results in undesired cases like short circuit in operation, reduced product life and so on.
The present application is aimed at proposing a device for softening an electrical heating wire coated with a hard insulating skin, as being sewn, so as to ensure that the electrical heating wire is able to be sewn onto a carrier of a heating cushion with the skin being undamaged.
According to one aspect of the present application, an electrical heating element is provided, which comprises an electrical heating wire and an outer insulating layer with which the electrical heating wire is coated, wherein said electrical heating element has a bending that is adapted to be secured on a cushion, and wherein said bending is not able to be bent into a straight line at room temperature without damaging said outer insulating layer or said electrical heating wire.
Optionally, said bending has a bending radius of not greater than 6 mm, preferably between 1 and 6 mm, particular preferably between 4 and 6 mm.
Optionally, the electrical heating element has an outer diameter of less than 1.5 mm; and/or the outer insulating layer has a thickness of between 0.01 and 0.2 mm, preferably between 0.1 and 0.2 mm.
Optionally, the outer insulating layer is made of a polymeric material, preferably PA12 or PES.
Optionally, the electrical heating element has an operating temperature of not greater than 150° C., and said bending is not able to be bent into a straight line at said operating temperature without damaging said outer insulating layer or said electrical heating wire.
According to another aspect of the present application an electrical heating device, especially an electrical heating cushion, in particular for a vehicle is provided, wherein said electrical heating device comprises a carrier and the previously mentioned electrical heating element secured on said carrier.
Optionally, a bending of said electrical heating element is secured on the carrier by sewing with threads. In a preferred embodiment, the threads are made of polyester.
Optionally, said threads for securing the bending of the electrical heating element have a stitch length of not greater than 2 mm.
According to another aspect of the present application, a softening device by which an outer insulating layer of an elongate electrical heating element to be secured onto a cushion, especially a vehicle seat or rest cushion is able to be softened is provided, wherein the softening device comprises:
Optionally, the gas passage and the feeding passage are defined within the body.
Optionally, the gas passage comprises a first gas passage section, upstream located, and a second gas passage section, downstream located, and wherein the second gas passage section is substantially parallel to the feeding passage.
Optionally, the softening device comprises a connecting tube by which the electrical heating element discharged out of the body is kept warm.
Optionally, the softening device comprises an outlet connection member releasably installed onto the body, the outlet connection member is provided with a passage cavity through which the electrical heating element passes, and the connecting tube is air-tightly coupled to the passage cavity.
Optionally, the connecting tube comprises a corrugated tube, a length of spiral spring is secured within the corrugated tube adjacent to the passage cavity, and the electrical heating element passes through a hollow interior of the spiral spring.
Optionally, the spiral spring is secured within the corrugated tube in an interference fitting manner.
Optionally, after the outlet connection member is installed in place, the passage cavity is in air-tight communication with the open cavity, and the passage cavity is provided with an internal circumferential side which narrows in a direction far away from the passage cavity.
Optionally, the softening device comprises a heat source which is able to generate the hot air driven through the gas passage.
Optionally, the softening device comprises a temperature sensor for measuring the temperature of the hot air.
According to another aspect of the present application, an apparatus for sewing an elongate electrical heating element having an outer insulating layer onto a cushion, especially a vehicle seat or rest cushion is provided, said apparatus comprising:
According to another aspect of the present application, a method for controlling the softening device as mentioned previously is provided, which comprises:
Optionally, the measured temperature value approaches a given value, the air velocity and/or the air temperature is enabled to decrease.
According to technical means mentioned above, the electrical heating element coated with the hard outer insulating skin can be softened prior to being sewn, such that the electrical heating element can be bent in a relatively complex pattern, i.e. with small radiuses but is not damaged. Furthermore, during the sewing, operation of the sewing head will not be hindered by the softened electrical heating element.
The foregoing and other aspects of the present application will be well understood by the following detailed description in combination with the attached drawings. It should be understood that although the drawings might be illustrated in different ratios for clarity, this does not affect understanding to the present application. In the drawings:
The same reference numerals are used to represent those features having the same or similar functions throughout the drawings of the present application.
In the present application, the electrical heating element can be an electrical heating elongate body which is coated with an insulating skin. The electrical heating elongate body can be sewn onto a carrier of the cushion by the sewing head 130 such that it can achieve a heating function after being energized. As mentioned in the background art part of the description, for the electrical heating metallic wire coated with the insulating skin, when it is being sewn in a pattern with small corners, the electrical heating metallic wire may be multiple bent, which may result in the relative hard insulating skin being broken and thus the electrical heating metallic wire being exposed.
Therefore, the sewing apparatus 100 is provided with a softening device 200 by which the electrical heating element can be warmed to be softened. According to one embodiment illustrated by
The heat source 220 can comprises an electrical heater device (not shown) and an air pump device (not shown). The electrical heater device can be controlled to be energized to produce heat and thus heat air. The heated air is blown by the air pump device through the heat-insulated pipeline 221 into the gas passage of the body 210, and the blowing volume and/or speed can be adjusted as required.
As shown by
An open cavity 213 is also provided within the body 210. The gas passage and the feeding passage 211 of the body 210 are isolated from each other such that only at the open cavity 213, the second passage section 212b is in communication with the feeding passage 211. In this way, hot air, after being blown into the gas passage of the body 210, will not be blown directly toward the electrical heating element to let its outer insulating skin be melted due to rapid heating. The hot air passing through the gas passage of the body 210 can be blown, only along a direction parallel to the feeding passage 211, into the open cavity 213. The electrical heating element is heated there such that its outer insulating skin can be gently warmed up and thus softened.
At the open cavity 213, the body 210 is able to be connected to an outlet connection member 230. For instance, the outlet connection member 230 is removably installed on the body 210 using a bolt or other means well known by one ordinary person in the art. A passage cavity 231 is formed in the outlet connection member 230. When the outlet connection member 230 is installed in place on the body 210, the passage cavity 231 is in communication with the open cavity 213. The passage cavity 231 penetrates through the outlet connection member 230. Furthermore, the passage cavity 231 is formed with an inner circumferential section which is tapered. The inner circumferential section is formed so as to taper toward a direction far away from the open cavity 213, such that hot air, after being conveyed there, can be slowed down to prevent “air-back” phenomenon from occurring.
Further as shown by
According to one embodiment of the present application, as shown by
Further as shown by
The corrugated tube 250 can constitute the connecting tube between the body 210 and the sewing head 130, and can be made of a plastic material or a heat-insulated material to ensure that as the softened electrical heating element 121 is being moved in the corrugated tube 250, the softened electrical heating element does not become hardened again because of rapid heat dissipation.
Using the inventive softening device, the electrical heating elongate element 121, for example before arriving at the sewing head 130, can be heated to a heat softening temperature at which the electrical heating element 121 can be secured in a manner of forming bending sections, for instance secured onto the carrier of the cushion by sewing, such that the electrical heating element 121 cannot be straightened at room temperature or a heating operating temperature (for example not greater than 150° C.) of the heating element 121 itself if the outer insulating skin or the heating wire is not damaged. In the context of the present application, the heating operating temperature refers to a tolerable temperature of the insulating skin of the heating element 121. In the present application, the heat softening temperature is higher than room temperature or the heating operating temperature of the heating element 121. Tat is to say, the bending sections of the heating element 121 are shape-cured at room temperature or the heating operating temperature, and they cannot be reshaped if the outer insulating skin or the heating wire is not damaged.
In the embodiment illustrated by
In order to monitor the temperature of hot air conveyed into the softening device 200, a temperature sensor 216 can be arranged in the first gas passage section 212a and/or the second gas passage section 212b. The air temperature measured by the temperature sensor 216 can indirectly reflect the temperature of the outer insulating skin of the electrical heating element 121, and thus the degree to which it is softened. It should be understood by the ordinary person in the art that it is also possible to arrange the temperature sensor 216 in the outlet connection member 230 and/or the secondary connection member 240 to respectively measure the temperature of hot air conveyed through them.
It should be understood by the ordinary person in the art that the inventive softening device 200 is not limited to the embodiments already mentioned by the description or illustrated by the drawings. For instance, in an alternative embodiment, the outlet connection member 230 and/or the secondary connection member 240 can be omitted, and the corrugated tube 250 can be air-tightly connected to the open cavity 213 of the body 210 directly in a manner known by the ordinary person in the art. For instance again, in an alternative embodiment, the first gas passage section 212a and/or the second gas passage section 212b can be provided in the body 210 and isolated from the feeding passage 211 in such a way that the first gas passage section 212a and/or the second gas passage section 212b is at an arbitrary angle relative to the feeding passage 211, as long as it is ensured that hot air in the gas passage will not be blown toward the electrical heating element along a direction perpendicular to the feeding passage 211.
In an alternative embodiment, the gas passage and the feeding passage 211 can be defined by independent heat-insulated pipes arranged outside of the body 210 such that the two pipes converge at the open cavity 213.
One embodiment of a control method for controlling the softening device according to the present application will be explained by referring to
According to the embodiment of the control method, at step S10, the softening device 200 is powered on. For instance, the electrical heater device and the air pump device of the heat source 220 are energized to operate. In this way, hot air is blown/driven into the gas passage of the softening device 200. Then, at step S20, the air's temperature is measured by the above-mentioned temperature sensor 216. At step S30, it is judged if a measured temperature value is greater than a predefined safe value. For instance, the safe value can be prescribed as a maximum safe temperature at which the electrical beating element is enabled to be softened when the softening device 20 is operated. That is, if this temperature is exceeded, the electrical heating element might be damaged due to excessive heat. If the judgment result at step S30 is “YES (Y)”, the process goes to step S90 and the softening device 200 is powered off. If the judgment result at step S30 is “NO (N)” the process goes to step S40. At step S40, it is judged if the measured temperature value is less than a predefined operating temperature. The operating temperature is less than the safe temperature. The predefined operating temperature is set such that when the hot air's temperature arrives at it, the outer insulating skin of the electrical heating element can be optimally softened to enable the sewing head 130 to produce a relatively complex sewing pattern. If the judgment result at step S40 is “N”, the process goes to step S90 and the softening device 200 is powered off. If the judgment result at step S40 is “Y”, the process goes to step S50.
At step S50, it is judged if an absolute value of the difference between the measured temperature value and the predefined operating temperature (value) arrives at a first limit value. If the judgment result at step S50 is “Y”, the process goes to step S60. If the judgment result at step S50 is “N”, the process goes to step S70. At step S70, it is judged if the absolute value of the difference between the measured temperature value and the predefined operating temperature (value) arrives at a second limit value. If the judgment result at step S70 is “Y”, the process goes to step S80. If the judgment result at step S70 is “N”, the process goes to step S20 and the process continue to circulate.
Step S60 and step S80 relate to temperature adjustment of hot air conveyed in the softening device 200. For instance, in an embodiment, the first limit value and the second limit value can be positive, and the first limit value is less than the second limit value. Furthermore, it can be provided at step S60 that the air pump device of the heat source 220 operates at low power such that hot air conveyed can be slowed down and thus the procedure during which the outer insulating skin of the electrical heating element is heated and softened is slowed down. Further, it can be provided at step S80 that the air pump device of the heat source 220 operates at high power such that the hot air conveyed can be speeded up and thus the procedure during which the outer insulating skin of the electrical heating element is heated and softened is also speeded up. Additionally or alternatively, in the above embodiment, the power of the electrical heater device of the heat source 220 can be adjusted respectively at step S60 and step S80, to change the temperature of the conveyed hot air, and thus the degree to which the outer insulating skin of the electrical heating element is softened by heating. The purpose of setting the first and second limit values is to let the temperature of hot air rise rapidly when the temperature is far away from the predefined operating temperature; and to let the temperature of hot air rise slowly when the temperature approaches to the predefined operating temperature, so as to prevent accumulative hot air from damaging the outer insulating skin of the electrical heating element. It should be understood by the ordinary person in the art that in an alternative embodiment the first limit value can be set to be greater than the second limit value. In this way, operations carried out at steps S60 and S80 can be reversed.
Using technical means already mentioned in the present application, an electrical heating element can be obtained, which comprises an electrical heating wire and an outer insulating layer with which the electrical heating wire is coated, wherein the electrical heating wire has a bending that is adapted to be secured on a cushion, and wherein the bending is not able to be bent into a straight line at room temperature without damaging the outer insulating layer or the electrical heating wire. The bending has a bending radius of not greater than 6 mm, preferably between 1 and 6 mm. The electrical heating element has an outer diameter of less than or equal to 1.5 mm. The outer insulating layer has a thickness of between 0.001 and 0.2 mm, preferably between 0.1 and 0.2 mm. The outer insulating layer is made of a polymeric material, preferably PA12 or PES.
It should be understood by the ordinary person in the art that using the technical means already mentioned in the present application, an electrical heating device, especially an electrical heating cushion, in particular for a vehicle can be obtained, which comprises a carrier and an electrical heating element secured on the carrier, wherein the electrical heating element comprises an electrical heating wire and an outer insulating layer with which the electrical heating wire is coated, wherein the electrical heating wire has a bending that is adapted to be secured on a cushion, and wherein the bending is not able to be bent into a straight line at room temperature without damaging the outer insulating layer or the electrical heating wire. In the context of the present application, the securing of the bending of the electrical heating element on the carrier can be achieved by sewing, wherein the sewing means that the bending of the electrical heating element is secured through the sewing head's sewing with threads on the carrier. The threads have a stitch length of not greater than 2 mm. In other optional embodiments, the electrical heating element can be secured on the carrier by other suitable means such as bonding.
Although some concrete embodiments of the present application have been explained here, they are given for illustrative purpose only and cannot be thought to constrain the scope of the present application in any way. Furthermore, it should be understood by the ordinary person in the art that the embodiments already described can be combined with each other. Without departing from the spirit and scope of the present application, various alternations, modifications and changes can be thought out.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201810095694.X | Jan 2018 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2019/073930 | 1/30/2019 | WO | 00 |
