Steering wheel heating system and heating film preparation method thereof

Abstract

The invention relates to a steering wheel heating system and a heating film preparation method thereof, the steering wheel heating system comprises a steering wheel, a heating unit, a detection unit and a control unit, the heating unit comprises a heating film body and an electrode, the heating film body wraps the steering wheel, and the electrode is arranged on the heating film body; the detection unit is used for collecting and sending the in-vehicle environment temperature. The control unit is connected with the temperature detection unit and used for comparing the received in-vehicle environment temperature with a first set temperature, and when the in-vehicle environment temperature is smaller than the first set temperature, the electrode is controlled to heat the heating film body. According to the automobile steering wheel heating device, the surface heating nanometer carbon film is adopted for heating, the manufactured heating film body can completely wrap the steering wheel in an attached mode, and when the environment temperature in an automobile is smaller than the first set temperature, the control unit controls the electrode to heat the heating film body so that the steering wheel can be heated; driving potential safety hazards caused by inflexible hitting directions due to cold hands are avoided, and the heating film body has the characteristics of high electrothermal conversion efficiency and low power consumption.

Description

Technical Field

[0001] The present application relates to the automotive field, and in particular to a steering wheel heating system and a method for preparing a heating film thereof. Background Art

[0002] In extremely cold regions, as the temperature gradually drops, the car becomes warmer with heating, but this does not mean that the seats, steering wheels and other parts are warm. When driving, cold hands may cause steering difficulties and create driving safety hazards, which does not provide the driver with a comfortable and safe driving experience. Summary of the invention

[0003] The present application provides a steering wheel heating system and a method for preparing a heating film thereof, which can solve the problem in the related art that when the temperature is low, the steering wheel is not warm and may cause steering inflexibility due to cold hands, resulting in driving safety hazards.

[0004] In a first aspect, an embodiment of the present application provides a steering wheel heating system, comprising: a steering wheel, a heating unit, a detection unit and a control unit, the heating unit comprising a heating film body and an electrode, the heating film body being wrapped around the steering wheel, and the electrode being arranged on the heating film body; the detection unit being used to collect and send the ambient temperature inside the vehicle; the control unit being connected to the temperature detection unit, and being used to compare the received ambient temperature inside the vehicle with a first set temperature, and when the ambient temperature inside the vehicle is lower than the first set temperature, the electrode is controlled to heat the heating film body.

[0005] In combination with the first aspect, in one embodiment, when the ambient temperature in the vehicle is lower than a first set temperature, the control electrode heats the heating film body using a first power;

[0006] When driving, after the control electrode heats the heating film body, when the ambient temperature inside the vehicle is greater than or equal to the first set temperature and less than the second set temperature, the control electrode uses the second power to heat the heating film body;

[0007] The first power is greater than the second power.

[0008] In combination with the first aspect, in one embodiment, after the electrode heats the heating film body, when the ambient temperature in the vehicle is greater than or equal to the second set temperature within a set time, the electrode is controlled to stop heating the heating film body.

[0009] In combination with the first aspect, in one embodiment, the steering wheel heating system further includes an alarm, which is connected to the control unit, and when the ambient temperature in the vehicle is greater than or equal to the second set temperature within a set time, the alarm sounds an alarm.

[0010] In combination with the first aspect, in one embodiment, the heating film body includes: a first wrapping area and a second wrapping area, the first wrapping area wraps the steering wheel along the outer periphery of the steering wheel; the second wrapping area is arranged on both sides of the first wrapping area and wraps the steering wheel along the radial direction of the steering wheel.

[0011] In combination with the first aspect, in one embodiment, a cutting line is provided on the second wrapping area, the cutting line is perpendicular to the first wrapping area, and the cutting lines located on both sides of the first wrapping area are staggered;

[0012] The first wrapping area and the second wrapping area are both provided with an electrode pasting portion;

[0013] An avoidance area is provided on the second wrapping area.

[0014] In combination with the first aspect, in one embodiment, a hollow hole and a shear line are provided in the middle of the heating film body;

[0015] A recessed portion is formed on the electrode, and the recessed portion corresponds to the shearing line and the hollow hole.

[0016] In combination with the first aspect, in one implementation, the steering wheel heating system further includes a power supply unit, the power supply unit includes a battery, the detection unit is connected to the battery and is further used to collect and send a battery SOC value, and the battery is connected to the electrode;

[0017] When the vehicle interior ambient temperature is lower than the first set temperature and the battery SOC value is greater than or equal to a set threshold, the control unit controls the electrode to heat the heating film body.

[0018] In combination with the first aspect, in one implementation, the power supply unit further includes a generator, and the generator is connected to the electrode;

[0019] When the vehicle is driving, the control unit controls the generator to supply power to the electrodes, and when the vehicle is parked, the control unit controls the battery to supply power to the electrodes;

[0020] When the vehicle is parked, when the battery SOC value is less than the set threshold, the control unit controls the heating unit to stop working.

[0021] In a second aspect, an embodiment of the present application provides a method for preparing a heating film, the method being used to prepare the heating film body as described above, and the preparation method specifically comprises:

[0022] Mixing the carbon material and the dry powder binder at a set speed for a set time to form a carbon material mixture;

[0023] Covering the carbon material mixture on the surface of the substrate to form a uniform carbon film;

[0024] The substrate with the carbon film is pressed with a hot roller to form a heating film body.

[0025] The beneficial effects brought by the technical solution provided in the embodiments of the present application include:

[0026] The embodiment of the present application provides a steering wheel heating system and a method for preparing a heating film thereof, which adopts surface heating of a nano-carbon film so that the manufactured heating film body can be completely wrapped around the steering wheel. When the ambient temperature in the vehicle is lower than the first set temperature, the control unit controls the electrode to heat the heating film body to heat the steering wheel, thereby avoiding driving safety hazards caused by inflexible steering due to cold hands. The heating film body has high electric heat conversion efficiency and low power consumption. The heating film body is soft and breathable. After installation, there is no foreign body feeling, tile toughness or roughness, and it can provide a uniform and moderate temperature thermal comfort experience on leather and wooden surfaces. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 A schematic diagram of a first heating mold body and electrodes provided in an embodiment of the present application;

[0029] Figure 2 A schematic diagram of a first heating mold body and electrodes provided in an embodiment of the present application;

[0030] Figure 3 A schematic diagram of a steering wheel wrapped by a heating mold body provided in an embodiment of the present application;

[0031] Figure 4 A schematic diagram of a steering wheel wrapped by a heating mold body provided in an embodiment of the present application;

[0032] Figure 5 A schematic diagram of the connection method of the heating unit switch provided in an embodiment of the present application;

[0033] Figure 6 A schematic diagram of a second electrode provided in an embodiment of the present application;

[0034] Figure 7 A schematic diagram of a second heating mold body provided in an embodiment of the present application;

[0035] Figure 8 A schematic diagram of a second heating mold body and electrodes provided in an embodiment of the present application.

[0036] In the figure: 1. Heating film body; 10. First wrapping area; 11. Second wrapping area; 12. Avoidance area; 13. Hollow hole; 2. Cutting line; 3. Electrode pasting part; 4. Steering wheel; 5. Electromagnetic switch; 6. Rocker switch; 7. Electrode; 70. Conductive electrode; 71. Power-on electrode; 72. Recessed part. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] See also Figures 1 to 8 The embodiment of the present application provides a steering wheel heating system and a method for preparing a heating film thereof, which can solve the problem in the related art that when the temperature is low, the steering wheel is not warm and may cause steering difficulties due to cold hands, resulting in driving safety hazards.

[0039] In the first aspect, an embodiment of the present application provides a steering wheel heating system, which includes: a steering wheel 4, a heating unit, a detection unit and a control unit, the heating unit includes a heating film body 1 and an electrode 7, the heating film body 1 is wrapped on the steering wheel 4, and the electrode 7 is arranged on the heating film body 1; the detection unit is used to collect and send the ambient temperature inside the vehicle; the control unit is connected to the temperature detection unit, and is used to compare the received ambient temperature inside the vehicle with a first set temperature, when the ambient temperature inside the vehicle is lower than the first set temperature, the electrode 7 is controlled to heat the heating film body 1.

[0040] In the present application, surface heating of nano-carbon film is adopted so that the heating film body 1 can be completely wrapped around the steering wheel 4. When the ambient temperature in the vehicle is lower than the first set temperature, the control unit controls the electrode 7 to heat the heating film body 1 so as to heat the steering wheel, thereby avoiding the hidden danger of driving safety caused by the inflexible steering due to the cold hands. The heating film body 1 has high electric heat conversion efficiency and low power consumption. The heating film body 1 is soft and breathable. There is no foreign body feeling, tile toughness or roughness after installation, and it can provide a uniform and moderate temperature thermal comfort experience on leather and wooden surfaces.

[0041] Among them, the heating film body 1 is prepared by electrostatic screen printing, and the specific method is: mixing the carbon material and the dry powder adhesive at a set speed for a set time to form a carbon material mixture; covering the carbon material mixture on the surface of the substrate to form a uniform carbon film; and hot roller pressing the substrate with the carbon film to form the heating film body 1.

[0042] Specific:

[0043] The carbon material and the dry powder binder are mixed at a set speed for a set time to form a carbon material mixture, specifically:

[0044] A planetary mixer is used to mix the carbon material and the dry powder binder for 2-5 hours at a dispersion speed of 2500r / min-4000r / min and a stirring speed of 40r / min-60r / min to obtain a carbon material mixture. The carbon material is one or a mixture of carbon materials such as carbon tubes, carbon fibers, graphite, carbon black, and graphene; the dry powder binder is one of polytetrafluoroethylene (PTFE), ethylene-tetrachloroethylene copolymer (ETEF), and tetrachloroethylene-hexachloropropylene copolymer (FEP). In this embodiment, polytetrafluoroethylene (PTFE) is preferred.

[0045] The carbon material mixture is then covered on the substrate surface to form a uniform carbon film:

[0046] In this embodiment, electrostatic screen printing can be used. Electrostatic screen printing is a method of transferring ink from the screen printing plate to the printing surface by using electrostatic attraction. In this embodiment, a conductive metal screen is used as a printing plate, which is connected to the positive electrode of a high-voltage power supply, and the negative electrode is a metal plate parallel to the printing plate, and the substrate is between the two levels. During printing, under the high voltage of the high-voltage power supply, the carbon powder on the printing plate is positively charged when passing through the stainless steel metal mesh, and the positively charged carbon material mixture is attracted by the negative charge and deposited on the substrate to be printed. Among them, the electric field force received by the carbon material mixture particles is proportional to the voltage of the electrostatic field and the charge of the particles, and inversely proportional to the distance between the spray gun and the workpiece. When the voltage is high enough, an air ionization zone is formed in the area near the stainless steel metal mesh, and the air is violently ionized and heated, and then the air generates a strong corona discharge. The carbon material mixture is charged due to contact when passing through the stainless steel metal mesh, and when passing through the gas ionization zone generated by the corona discharge, its surface charge density will increase again. These positively charged carbon material mixture particles move toward the metal plate with a conductive polarity under the action of the electrostatic field and are deposited on the surface of the substrate to form a uniform carbon film. In this embodiment, the high voltage is 50-70KV, the printing distance is 15cm-35cm; the substrate can be one of the materials such as cloth, silk scarf, metal film, etc.

[0047] Finally, the substrate with the carbon film is pressed with a hot roller to form a heating film body 1:

[0048] The substrate after electrostatic screen printing is pressed between two rollers, and the temperature between the rollers is heated to between 50°C and 100°C, and the linear pressure load is 95N / mm-125N / mm, in order to fiberize the adhesive in the coated carbon material mixture and fix it on the substrate, and finally form the heating film body 1. The thickness of the heating material is between 10μm and 50μm, and the mass percentage of the adhesive PTFE is between 20% and 50%.

[0049] Among them, the principle of PTFE fiberization: the deformation of polymer crystals is due to crystal dislocation, and the polymer structure in the crystal has restrictions on the choice of slip plane. Since sliding will not cause chain breakage, it can only slide along a plane parallel to the polymer chain. The main modes are chain slip and lateral slip: the former is due to sliding along the chain axis, and the latter is sliding perpendicular to the axis. When the temperature is higher than 19 degrees, PTFE will transform from a triclinic system to a hexagonal system, the molecular chain will become soft, the cohesion between adjacent chains of the hexagonal crystal is low, and it will be easier to slide along the chain axis. Therefore, when a shear load is applied to the PTFE crystal, crystal slip occurs along the c-axis, the shape of the PTFE crystal changes, and a nanofiber structure with a high aspect ratio can be formed.

[0050] PTFE bonding means: during the hot-roll pressing process, PTFE fiberization forms a three-dimensional network structure to aggregate the carbon material. Due to Brownian motion, the PTFE adhesive molecular chain moves from one phase to another, and the two are intertwined, causing the interface between them to disappear and become a transition zone. Finally, a mutually penetrating polymer network structure is formed in the transition zone, thereby obtaining a very high bonding strength.

[0051] In addition, the nano-carbon film in the present application can be obtained by electrostatic screen printing or by electrostatic spraying. Specifically, the carbon material mixture particles are placed in a spray gun (spray cup), the spray gun is connected to the negative pole, the metal aluminum foil (copper foil) is connected to the positive pole, and high-frequency high-voltage direct current is passed through the spray gun to form a strong electromagnetic field around the spray object. The carbon material mixture is brought into the electromagnetic field by compressed air, and is negatively charged and flies to the surface of the aluminum foil (copper foil) of the spray object. The heating film body 1 can be obtained by hot roller pressing. The compressed air pressure is 0.08-0.4MPa, and the spray distance is 15-35cm. The DC voltage range is 60-100kv.

[0052] After the heating film body 1 is manufactured, the electrodes 7 are attached and then cut.

[0053] In some possible embodiments, the heating film body 1 can be cut according to the following Figure 1 and Figure 2 Cut to the shape shown.

[0054] In this embodiment, the heating film body 1 includes: a first wrapping area 10 and a second wrapping area 11, see Figure 4 As shown, the first wrapping area 10 wraps the steering wheel 4 along the outer periphery of the steering wheel 4 ; the second wrapping area 11 is arranged on both sides of the first wrapping area 10 , and wraps the steering wheel 4 along the radial direction of the steering wheel 4 .

[0055] In order to ensure the flatness of the second wrapping area 11 including the steering wheel 4, a cutting line 2 is provided on the second wrapping area 11, such as Figure 1 As shown in the single horizontal solid line, the cutting line 2 is perpendicular to the first wrapping area 10, and the cutting lines 2 on both sides of the first wrapping area 10 are arranged alternately, that is, when the second wrapping area 11 is cut by the cutting line 2, it is divided into a plurality of small wrapping areas, and when the small wrapping areas wrap the steering wheel 4 along the radial direction of the steering wheel 4, the small wrapping areas on both sides of the first wrapping area 10 overlap and fit each other, and alternately wrap and fix the steering wheel 4. The arrangement of this structure can improve the flatness of the steering wheel heating without losing the heating area, and provide an efficient and comfortable heating environment;

[0056] Furthermore, to ensure that the first wrapping area 10 and the second wrapping area 11 are both provided with an electrode pasting portion 3 . Figure 1 To heat the front side of the film body 1 (nano carbon layer), Figure 2 The back side (insulating layer) of the heating film body 1 is provided, wherein the electrode 7 comprises a conducting electrode 70 and a powered electrode 71, wherein the powered electrode 71 (such as Figure 1 As shown by the double vertical dashed lines, Figure 2 Double vertical solid lines) are pasted on the back of the heating film body 1, Figure 1 The single horizontal solid line in the middle is the cutting line 2 , and the double vertical solid lines and the double horizontal short solid lines are the conducting electrodes 70 , wherein the cutting line 2 passes through the conducting electrodes 70 . Specifically, the conducting electrodes 70 represented by the double vertical solid lines are cut by the cutting line 2 . Figure 2 The double horizontal solid line in the figure is a conductive electrode 70, one end of which is connected to the powered electrode 71, and the other end is folded and connected to the corresponding electrode 7 on the opposite side (such as Figure 1 shown).

[0057] In addition, when the heating unit covers the steering wheel 4, an avoidance area 12 is provided on the second wrapping area 11. The avoidance area 12 is to avoid the frame of the middle area of ​​the steering wheel 4, so as to avoid unnecessary bulges or depressions that affect the user experience. When the heating film body 1 covers the frame of the steering wheel 4, the flatness of the heating film body 1 can be ensured, further improving the driver's comfort.

[0058] In some other possible embodiments, the electrodes 7 are distributed in an arc shape, and a hollow hole 13 and a cutting line 2 are provided in the middle of the heating film body 1 ; a recessed portion 72 is formed on the electrode 7 , and the recessed portion 72 corresponds to the cutting line 2 and the hollow hole 13 .

[0059] See also Figure 6-Figure 8 As shown, a hollow hole 13 is dug out in the middle of the heating film body 1, and the electrodes 7 are respectively pasted on both sides of the long side of the heating film body 1, wherein the cutting line 2 is cut along the recessed portion 72, i.e., the recessed part of the electrode 7, and ensures that the electrode 7 cannot be cut. The purpose of drilling the hollow hole 13 in the middle of the heating film body 1 is to ensure that the current is evenly distributed on the heating surface of the heating film body 1, and at the same time, no local high temperature is generated at the position of the hollow hole 13.

[0060] After the electrode 7 is pasted on the heating film body 1, the heating film body 1 is wrapped on the skeleton of the steering wheel 4. The power cord of the electrode 7 is connected to the rotating shaft through the bottom of the steering wheel 4, and then a layer of leather is sewn on the surface of the heating film body 1. The heating of the steering wheel 4 can be partially covered at the 3 o'clock and 9 o'clock directions. This design can heat the position where the driver's hands are often held, which is both energy-saving and efficient; it can also be fully covered for heating, that is, the heating unit is evenly distributed on the entire steering wheel 4 skeleton to provide a full range of heating effects. The heating film body 1 in the present invention has high electric heat conversion efficiency and low power consumption. The heating film body 1 is soft and breathable. After installation, there is no foreign body feeling, tile toughness or roughness. It can provide a uniform and moderate temperature thermal comfort experience on leather and wooden surfaces. The heating unit of the present application can cover any car interior surface. In addition to the steering wheel 4, it can also be door panels, armrests, center consoles, seat backs, headrests, etc. to heat the covered area.

[0061] Furthermore, in this embodiment, the first set temperature is set to 10° C., and when the vehicle interior ambient temperature is lower than 10° C., the control unit controls the heating unit to start. It should be noted that in other embodiments, the first set temperature may have other setting schemes, which need to be determined according to actual conditions.

[0062] On the basis of the above embodiments, in this embodiment, when the ambient temperature inside the vehicle is lower than the first set temperature, the control electrode 7 uses the first power to heat the heating film body 1; when driving, after the control electrode 7 heats the heating film body 1, when the ambient temperature inside the vehicle is greater than or equal to the first set temperature and lower than the second set temperature, the control electrode 7 uses the second power to heat the heating film body 1; and the first power is greater than the second power.

[0063] Specifically, in this embodiment, it is necessary to determine whether to turn on the heating unit according to the ambient temperature in the car. After turning it on, it is also necessary to determine the power of the heating unit according to the ambient temperature in the car. In this embodiment, the first set temperature is set to 10°C and the second set temperature is set to 25°C. When the ambient temperature in the car is lower than 10°C, the control unit controls the heating unit to start and the heating unit works at full power. During driving, the ambient temperature in the car rises as the air conditioner heats up. When the detection unit detects that the ambient temperature in the car is greater than or equal to 10°C and less than 25°C, the heating unit works at a reduced power. This setting method can save energy.

[0064] The power regulation is controlled by the control unit. When the ambient temperature in the car is greater than or equal to 10°C and less than 25°C, the heating power can also be refined. For example, if the heating film body 1 covers the steering wheel 4 in all directions, the rated heating power is 120W, and the ambient temperature in the car is 10-20°C and the duration is greater than 30 minutes, the heating power is 80W; when the ambient temperature in the car is 20-25°C and the duration is greater than 30 minutes, the heating power is 40W.

[0065] Furthermore, after the electrode 7 heats the heating film body 1, when the ambient temperature in the vehicle is greater than or equal to the second set temperature within the set time, the electrode 7 is controlled to stop heating the heating film body 1. In other words, the ambient temperature in the vehicle rises as the air conditioner heats up. When it is detected that the ambient temperature in the vehicle is greater than or equal to 25°C and the duration is greater than 30 minutes, the heating function of the steering wheel 4 stops working.

[0066] On the basis of the above embodiment, in this embodiment, the steering wheel heating system further includes an alarm, which is connected to the control unit. When the ambient temperature inside the vehicle is greater than or equal to the second set temperature within a set time, the alarm sounds an alarm.

[0067] In this embodiment, the heating unit connector of the steering wheel heating system is connected to the clock spring connector. When the control unit detects that the ambient temperature in the vehicle is greater than 25°C and lasts for more than 30 minutes, the instrument buzzes for 1 second, the control unit controls the electromagnetic switch 5 to disconnect, and the heating function of the heating unit stops working. If the steering wheel heating function needs to continue to work, the rocker switch 6 can be manually closed to start the heating unit for heating. The connection method of the switch of the heating unit is as follows Figure 5 As shown, the rocker switch 6 is normally open, which means that in the absence of external operation or current activation, the contact of the rocker switch 6 is in an open state and does not allow current to pass.

[0068] On the basis of the above embodiment, in this embodiment, the steering wheel heating system further includes a power supply unit, the power supply unit includes a battery, the detection unit is connected to the battery, and is also used to collect and send the battery SOC value, and the battery is connected to the electrode 7. When the vehicle interior ambient temperature is lower than the first set temperature and the battery SOC value is greater than or equal to the set threshold, the control unit controls the electrode 7 to heat the heating film body 1.

[0069] Specifically, in this embodiment, a battery is used to power the heating unit. The advantage of using a battery for the heating unit is that it can ensure that the heating unit works continuously and stably without being restricted by power outages in the absence of external power supply.

[0070] However, when the battery heats the heating unit, it is necessary to determine the battery SOC value. When the ambient temperature in the vehicle is lower than the first set temperature, if the battery is used for power supply, it is necessary to first determine the battery SOC (State of Charge, i.e., the remaining power) value. When the ambient temperature in the vehicle drops below the first set temperature, the battery SOC value must also be considered. Specifically, if it is detected that the battery SOC value is lower than a set threshold, the battery will not automatically supply power to the heating unit for the purpose of protecting the battery and preventing over-discharge, so as to avoid damage to the battery or shortening its service life. In this embodiment, it can be set that when the battery SOC value is less than 20, the power supply to the heating unit is stopped. Only when the battery SOC value is greater than or equal to 20 and the ambient temperature in the vehicle is lower than the first set temperature, the heating unit can start to work.

[0071] In addition, it is set that when the battery SOC value is less than 20, the control unit controls the alarm to sound an alarm. Specifically, when the battery SOC value is less than 20, the instrument buzzes for 5s, and the instrument sends a reminder "The battery power is low". After timing for 30S, the control unit sends a shutdown signal to the heating unit, and the instrument sends a reminder "The battery power is low, and the heating function is turned off".

[0072] On the basis of the above embodiment, the power supply unit further includes a generator, and the generator is connected to the electrode 7. In this embodiment, both the generator and the battery are connected to the electrode 7 of the heating unit. The advantage of this design is that it realizes dual power supply guarantee for the heating unit. When the generator is running, it can directly provide stable power to the heating unit; when the generator cannot work or the power is insufficient, the battery can be used as a backup power supply, seamlessly relaying, ensuring that the heating unit continues to work unaffected. Such a configuration not only improves the reliability of power supply, but also enhances the flexibility and adaptability of the entire system.

[0073] Specifically, when driving, the control unit controls the generator to supply power to the electrode 7 to meet the demand for heating the steering wheel 4 during driving; when parking, that is, the vehicle is in the engine stop state, the control unit automatically switches to the mode of supplying power to the electrode 7 by the battery, ensuring that the necessary heating function can be maintained when the vehicle is stationary, thereby maintaining the comfort of the vehicle interior environment.

[0074] However, it should be noted that when parking, when the battery SOC value is less than the set threshold, in order to effectively protect the battery and prevent it from over-discharging, the control unit controls the heating unit to stop working to avoid unnecessary damage to the battery.

[0075] In summary, the steering wheel heating system provided in the present application can heat the steering wheel, and can make the steering wheel 4 warm in cold seasons, so that the driver no longer feels cold and uncomfortable when holding the steering wheel 4. Steering wheel heating can avoid the hidden danger of driving safety caused by inflexible steering due to cold hands, and provide the driver with a comfortable and safe driving experience.

[0076] In a second aspect, an embodiment of the present application provides a method for preparing a heating film, which is used to prepare the above heating film body 1, and the preparation method specifically includes:

[0077] The carbon material and the dry powder adhesive are mixed at a set speed for a set time to form a carbon material mixture; the carbon material mixture is covered on the surface of the substrate to form a uniform carbon film; the substrate with the carbon film is pressed by a hot roller to form a heating film body 1.

[0078] Specific:

[0079] The carbon material and the dry powder binder are mixed at a set speed for a set time to form a carbon material mixture, specifically:

[0080] A planetary mixer is used to mix the carbon material and the dry powder binder for 2-5 hours at a dispersion speed of 2500r / min-4000r / min and a stirring speed of 40r / min-60r / min to obtain a carbon material mixture. The carbon material is one or a mixture of carbon materials such as carbon tubes, carbon fibers, graphite, carbon black, and graphene; the dry powder binder is one of polytetrafluoroethylene (PTFE), ethylene-tetrachloroethylene copolymer (ETEF), and tetrachloroethylene-hexachloropropylene copolymer (FEP). In this embodiment, polytetrafluoroethylene (PTFE) is preferred.

[0081] The carbon material mixture is then covered on the substrate surface to form a uniform carbon film:

[0082] In this embodiment, electrostatic screen printing can be used. Electrostatic screen printing is a method of transferring ink from the screen printing plate to the printing surface by using electrostatic attraction. In this embodiment, a conductive metal screen is used as a printing plate, which is connected to the positive electrode of a high-voltage power supply, and the negative electrode is a metal plate parallel to the printing plate, and the substrate is between the two levels. During printing, under the high voltage of the high-voltage power supply, the carbon powder on the printing plate is positively charged when passing through the stainless steel metal mesh, and the positively charged carbon material mixture is attracted by the negative charge and deposited on the substrate to be printed. Among them, the electric field force received by the carbon material mixture particles is proportional to the voltage of the electrostatic field and the charge of the particles, and inversely proportional to the distance between the spray gun and the workpiece. When the voltage is high enough, an air ionization zone is formed in the area near the stainless steel metal mesh, and the air is violently ionized and heated, and then the air generates a strong corona discharge. The carbon material mixture is charged due to contact when passing through the stainless steel metal mesh, and when passing through the gas ionization zone generated by the corona discharge, its surface charge density will increase again. These positively charged carbon material mixture particles move toward the metal plate with a conductive polarity under the action of the electrostatic field and are deposited on the surface of the substrate to form a uniform carbon film. In this embodiment, the high voltage is 50-70KV, the printing distance is 15cm-35cm; the substrate can be one of the materials such as cloth, silk scarf, metal film, etc.

[0083] Finally, the substrate with the carbon film is pressed with a hot roller to form a heating film body 1:

[0084] The substrate after electrostatic screen printing is pressed between two rollers, and the temperature between the rollers is heated to between 50°C and 100°C, and the linear pressure load is 95N / mm-125N / mm, in order to fiberize the adhesive in the coated carbon material mixture and fix it on the substrate, and finally form the heating film body 1. The thickness of the heating film body 1 is between 10μm and 50μm, and the mass percentage of the adhesive PTFE is between 20% and 50%.

[0085] Among them, the principle of PTFE fiberization: the deformation of polymer crystals is due to crystal dislocation, and the polymer structure in the crystal has restrictions on the choice of slip plane. Since sliding will not cause chain breakage, it can only slide along a plane parallel to the polymer chain. The main modes are chain slip and lateral slip: the former is due to sliding along the chain axis, and the latter is sliding perpendicular to the axis. When the temperature is higher than 19 degrees, PTFE will transform from a triclinic system to a hexagonal system, the molecular chain will become soft, the cohesion between adjacent chains of the hexagonal crystal is low, and it will be easier to slide along the chain axis. Therefore, when a shear load is applied to the PTFE crystal, crystal slip occurs along the c-axis, the shape of the PTFE crystal changes, and a nanofiber structure with a high aspect ratio can be formed.

[0086] PTFE bonding means: during the hot-roll pressing process, PTFE fiberization forms a three-dimensional network structure to aggregate the carbon material. Due to Brownian motion, the PTFE adhesive molecular chain moves from one phase to another, and the two are intertwined, causing the interface between them to disappear and become a transition zone. Finally, a mutually penetrating polymer network structure is formed in the transition zone, thereby obtaining a very high bonding strength.

[0087] In addition, the nano-carbon film in the present application can be obtained by electrostatic screen printing or by electrostatic spraying. Specifically, the carbon material mixture particles are placed in a spray gun (spray cup), the spray gun is connected to the negative pole, the metal aluminum foil (copper foil) is connected to the positive pole, and high-frequency high-voltage direct current is passed through the spray gun to form a strong electromagnetic field around the spray object. The carbon material mixture is brought into the electromagnetic field by compressed air, and is negatively charged and flies to the surface of the aluminum foil (copper foil) of the spray object. The heating film body 1 can be obtained by hot roller pressing. The compressed air pressure is 0.08-0.4MPa, and the spray distance is 15-35cm. The DC voltage range is 60-100kv.

[0088] After the heating film body 1 is manufactured, the electrodes 7 are attached and then cut.

[0089] Two embodiments are used as examples for specific description:

[0090] Embodiment 1:

[0091] First, a planetary mixer is used to mix carbon nanotubes and PTEF dry powder for 2 hours at a dispersion speed of 2500r / min and a stirring speed of 40r / min to obtain a mixture of carbon nanotubes and PTFE. Then electrostatic screen printing is performed, and a stainless steel metal screen is used as a printing plate, connected to the positive electrode of a high-voltage power supply, and the negative electrode is a metal plate parallel to the printing plate, and the cloth to be printed is between the two poles. The voltage of the high-voltage power supply is 50kv, and the distance between the two plates is 15cm. Finally, hot roller pressing is performed, and the cloth after the electrostatic screen printing is pressed between two rollers, and the rollers are heated to 70°C, and the linear pressure load is 95N / mm. The purpose is to fiberize the PTFE and fix the carbon material mixture on the cloth, and finally form the heating membrane body 1. The thickness of the heating material is 20um, and the mass percentage of the adhesive PTFE is about 20%.

[0092] Embodiment 2:

[0093] First, a planetary mixer is used to mix carbon nanotubes and PTEF dry powder for 2 hours at a dispersion speed of 2500r / min and a stirring speed of 40r / min. The fiberized polytetrafluoroethylene (PTFE) forms fibers under high shear force and is mixed with carbon tube fibers to obtain carbon material mixture particles. Then, electrostatic spraying is performed, and the carbon material mixture particles are placed in a spray gun, the spray gun is connected to the negative electrode, and the metal aluminum foil is connected to the positive electrode. A 60kv high-frequency high-voltage direct current is passed through the spray gun to form a strong electromagnetic field around the spray object. The carbon material mixture particles are brought into the electromagnetic field by compressed air, and are negatively charged and fly to the surface of the sprayed aluminum foil (copper foil). The compressed air pressure is 0.2MPa and the spray distance is 25cm. Finally, hot roller pressing is performed, and the aluminum foil after the electrostatic spraying is pressed between two rollers. The rollers are heated to 70°C and the linear pressure load is 95N / mm. The purpose is to fix the carbon tube and PTFE fiber mixture on the aluminum foil, and finally form the heating membrane body 1. The thickness of the heating film body 1 is 20 um, and the mass percentage of the adhesive PTFE is about 20%.

[0094] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0095] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0096] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A steering wheel heating system, characterized in that: It includes: Steering wheel (4); A heating unit, the heating unit comprising a heating film body (1) and an electrode (7), the heating film body (1) being wrapped around the steering wheel (4), and the electrode (7) being arranged on the heating film body (1); A detection unit, the detection unit is used to collect and send the vehicle interior environment temperature; A control unit is connected to the temperature detection unit and is used to compare the received in-vehicle ambient temperature with a first set temperature. When the in-vehicle ambient temperature is lower than the first set temperature, the control electrode (7) is controlled to heat the heating film body (1).

2. The steering wheel heating system according to claim 1, characterized in that: When the ambient temperature in the vehicle is lower than a first set temperature, the control electrode (7) uses a first power to heat the heating film body (1); When the vehicle is in motion, after the control electrode (7) heats the heating film body (1), when the ambient temperature inside the vehicle is greater than or equal to the first set temperature and less than the second set temperature, the control electrode (7) uses the second power to heat the heating film body (1); The first power is greater than the second power.

3. The steering wheel heating system according to claim 2, characterized in that: After the electrode (7) heats the heating film body (1), when the ambient temperature inside the vehicle is greater than or equal to the second set temperature within a set time, the electrode (7) is controlled to stop heating the heating film body (1).

4. The steering wheel heating system according to claim 3, characterized in that: The steering wheel heating system also includes an alarm, which is connected to the control unit. When the ambient temperature in the vehicle is greater than or equal to the second set temperature within a set time, the alarm sounds an alarm.

5. The steering wheel heating system according to claim 1, characterized in that: The heating film body (1) comprises: A first wrapping area (10), wherein the first wrapping area (10) wraps the steering wheel (4) along the outer periphery of the steering wheel (4); A second wrapping area (11), wherein the second wrapping area (11) is arranged on both sides of the first wrapping area (10) and wraps the steering wheel (4) along the radial direction of the steering wheel (4).

6. The steering wheel heating system according to claim 5, characterized in that: The second wrapping area (11) is provided with a cutting line (2), the cutting line (2) is perpendicular to the first wrapping area (10), and the cutting lines (2) located on both sides of the first wrapping area (10) are arranged in a staggered manner; The first wrapping area (10) and the second wrapping area (11) are both provided with an electrode pasting portion (3); The second wrapping area (11) is provided with an avoidance area (12).

7. The steering wheel heating system according to claim 1, characterized in that: The heating film body (1) is provided with a hollow hole (13) and a shear line (2) in the middle; A recessed portion (72) is formed on the electrode (7), and the recessed portion corresponds to the shear line (2) and the hollow hole (13).

8. The steering wheel heating system according to claim 1, characterized in that: The steering wheel heating system further comprises a power supply unit, the power supply unit comprises a battery, the detection unit is connected to the battery and is also used to collect and send the battery SOC value, the battery is connected to the electrode (7); When the ambient temperature in the vehicle is lower than a first set temperature and the battery SOC value is greater than or equal to a set threshold, the control unit controls the electrode (7) to heat the heating film body (1).

9. The steering wheel heating system according to claim 8, characterized in that: The power supply unit further comprises a generator, which is connected to the electrode (7); When the vehicle is in motion, the control unit controls the generator to supply power to the electrode (7); when the vehicle is parked, the control unit controls the battery to supply power to the electrode (7); When the vehicle is parked, when the battery SOC value is less than the set threshold, the control unit controls the heating unit to stop working.

10. A method for preparing a heating film, characterized in that: The method is used to prepare the heating film body (1) as claimed in claim 1, and the preparation method specifically comprises: Mixing the carbon material and the dry powder binder at a set speed for a set time to form a carbon material mixture; Covering the carbon material mixture on the surface of the substrate to form a uniform carbon film; The substrate with the carbon film is pressed with a hot roller to form a heating film body (1).

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