Spiral heating wire of vehicle seat and preparation method of spiral heating wire

Abstract

According to the spiral heating wire of the vehicle seat and the preparation method of the spiral heating wire, conductor materials made of nickel-chromium alloy materials are adopted, meanwhile, basalt fiber ropes with the characteristics of high tensile strength, high temperature resistance and the like are selected as center filling materials, and XLPVC or XLPE resistant to high temperature and high insulation resistance is selected as insulating layer materials. Compared with a traditional heating wire, the service life is prolonged from 60,000 times to 120,000 times, and the overall bending-resistant service life is prolonged by 50%. In the preparation process of the spiral heating wire, in the annealing process treatment stage, the temperature is increased to 800 DEG C at the speed of 10 DEG C / min under the hydrogen protection atmosphere, and slow cooling is conducted after heat preservation is conducted for 30 min; according to the cable manufactured through the method, the temperature difference of the surface of the seat can be smaller than or equal to 1.5 DEG C, and the problem that heat of a traditional seat is not uniform is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of heating wires, and specifically relates to a spiral heating wire for a vehicle seat and a preparation method thereof. Background Art

[0002] With the rapid development of the automotive industry and the increasing demand of consumers for driving and riding comfort, the function of automotive heated seats has gradually spread from the standard configuration of mid - to - high - end models to some low - end models, injecting more diverse choices for the consumer group in the low - end new energy vehicle market. According to data from market research firm Statista, the global market size of automotive heated seats reached $5.8 billion in 2023 and is expected to exceed $9 billion by 2030, with a compound annual growth rate of 6.3%. Against this background, the performance optimization of the spiral heating wire, the core component of heated seats, has become the key point of technological competition.

[0003] Traditional automotive seat heating wires generally consist of a central fiber, a metal wire, and a plastic cortex. The metal wire is spirally wound around the outside of the central fiber to form a metal wire layer, and the cortex is sleeved outside the metal wire layer. After repeated bending, stretching, or extrusion, the gap between the cortex and the metal wire becomes obvious, and the cortex cannot provide good protection for the metal wire, resulting in the metal wire being prone to breakage, causing the heating effect to fail, heating unevenly, being prone to local overheating, leading to discomfort for passengers, and even posing a safety hazard. In addition, the resistance design of some seat heating wires is unreasonable, resulting in waste of electric energy and high energy consumption, posing a great challenge to the electric energy consumption of new energy vehicles; at the same time, some materials contain heavy metals or difficult - to - degrade components, bringing greater environmental protection pressure. Summary of the Invention

[0004] One of the technical problems to be solved by the present invention is to provide a spiral heating wire for a vehicle seat with good temperature control uniformity, long life, and low energy consumption.

[0005] Another technical problem to be solved by the present invention is to provide a preparation method for a spiral heating wire for a vehicle seat with good temperature control uniformity, long life, and low energy consumption.

[0006] The present invention is implemented as follows:

[0007] Technical Solution One:

[0008] A spiral heating wire for a vehicle seat, which sequentially includes from the inside to the outside: a reinforcing filling layer, a cushion layer, a metal wire, a bonding layer, and an insulating layer;

[0009] The reinforcing filling layer uses a basalt fiber rope;

[0010] The cushion layer uses nylon or fluoroplastics;

[0011] The wire is made of nickel-chromium alloy and is spirally wound around the cushion layer with a spiral diameter of 23 mm and a pitch of 4 mm;

[0012] The insulating layer is XLPVC or XLPE.

[0013] Furthermore, the adhesive layer is made of EVA resin.

[0014] Technical solution two:

[0015] A preparation method of a spiral heating wire for a vehicle seat, comprising the following steps;

[0016] Step one: Core wire processing:

[0017] Including: wire drawing process and annealing treatment;

[0018] The wire drawing process is specifically: using a multi-mode continuous wire drawing machine, drawing wire with a die hole diameter tolerance of ±0.001 mm, and real-time monitoring the diameter fluctuation with an on-line laser diameter gauge to ensure the resistance consistency;

[0019] The annealing treatment is specifically: in a hydrogen protection atmosphere, heating to 800 °C at a rate of 10 °C / min, holding for 30 min and then cooling slowly;

[0020] Step two: Spiral winding:

[0021] Using a high-precision servo motor with a positioning accuracy of ±0.01 mm and a tension control system with a fluctuation of ≤±0.1 N for winding, and based on PID feedback adjustment, dynamically compensating for the elastic deformation of the material to ensure that the pitch error is ≤±0.05 mm;

[0022] Step three: Insulation coating:

[0023] Adopting a double-layer co-extrusion die head, the inner layer is an adhesive layer made of EVA resin, and the insulating layer is XLPVC or XLPE; then irradiating and crosslinking, with a crosslinking degree of ≥75%;

[0024] Step four: Quality monitoring:

[0025] Conducting electrical property tests and mechanical durability tests on the prepared spiral heating wire.

[0026] The present invention has the following advantages:

[0027] 1. Heating uniformity

[0028] For traditional vehicle seat heating wires, the temperature control uniformity is poor, and the heat is uneven. During use, it is easy to have poor temperature control, resulting in a temperature rise, bringing a bad experience to passengers; the cable of the present invention can achieve a temperature difference on the seat surface of ≤1.5 °C.

[0029] 2. Reducing energy consumption

[0030] In the process of the seat heating wire of the present invention, first, through an annealing process, it is heated to 800°C at a rate of 10°C / min under a hydrogen protection atmosphere, held for 30 minutes, and then slowly cooled; Effect: Eliminate internal stress, and the resistivity volatility drops from the traditional 5% to 1.5%. Further reducing the change in resistivity results in an obvious fluctuation in temperature.

[0031] 3. Improving the durability of the cable

[0032] The present invention uses a conductor material made of nickel-chromium alloy, and the resistance stability is improved by 20%. At the same time, the central filling material selects basalt fiber rope with characteristics such as high tensile strength and high temperature resistance, and the insulating layer material selects XLPVC or XLPE with high temperature resistance and high insulation resistance. Compared with the traditional heating wire, the service life is increased from 60,000 times to 120,000 times, and the overall bending resistance life is increased by 50%. This significantly improves the performance of the heating wire; combined with intelligent manufacturing processes, it realizes high consistency and low energy consumption production; integrated intelligent temperature control technology lays the foundation for future vehicle networking applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below with reference to the accompanying drawings in conjunction with embodiments.

[0034] Figure 1 It is a schematic structural diagram of the spiral heating wire of the present invention.

[0035] Reference numerals: 1, reinforcing filling layer; 2, cushion layer; 3, metal wire; 4, adhesive layer; 5, insulating layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0036] Embodiment 1:

[0037] Referring to Figure 1 As shown, this embodiment provides a spiral heating wire for a vehicle seat. The spiral heating wire sequentially includes from the inside to the outside: a reinforcing filling layer 1, a cushion layer 2, a metal wire 3, an adhesive layer 4, and an insulating layer 5; wherein the reinforcing filling layer 1 is made of basalt fiber rope; the cushion layer 2 is made of nylon or fluoroplastics; the metal wire 3 is made of nickel-chromium alloy and is spirally wound around the cushion layer 2 with a spiral diameter of 23 mm and a pitch of 4 mm; the adhesive layer 4 is made of EVA resin, and the insulating layer 5 is XLPVC or XLPE.

[0038] Embodiment 2:

[0039] This embodiment provides a preparation method for a spiral heating wire of a vehicle seat, which specifically includes the following steps:

[0040] Step 1: Core wire processing:

[0041] Including: wire drawing process and annealing treatment;

[0042] The wire drawing process is as follows: A multi - die continuous wire drawing machine is used, and wire drawing is carried out with the die aperture tolerance of ±0.001 mm. An on - line laser diameter gauge is used to monitor the diameter fluctuation in real - time to ensure the resistance consistency (deviation ≤ ±2%);

[0043] The annealing treatment is as follows: Under a hydrogen - protected atmosphere, it is heated to 800 °C at a rate of 10 °C / min, held for 30 min, and then slowly cooled; Effect: After the annealing treatment, the resistivity volatility drops from 5% to 1.5%.

[0044] Step Two: Spiral winding:

[0045] The metal wire 3 is wound using a high - precision servo motor with a positioning accuracy of ±0.01 mm and a tension control system with a fluctuation of ≤ ±0.1 N. Process parameters: winding speed 20 - 30 m / min, tension 0.5 - 1.0 N; Based on PID feedback regulation, the elastic deformation of the material is dynamically compensated to ensure that the pitch error ≤ ±0.05 mm;

[0046] Step Three: Insulation coating:

[0047] A double - layer co - extrusion die head is used. The inner layer is the adhesive layer 4 made of EVA resin, and the outer layer is the insulation layer 5 made of XLPVC or XLPE; Then it is irradiated and cross - linked, and the cross - linking degree ≥ 75%; Effect: The tracking resistance index reaches CTI 600V.

[0048] Step Four: Quality monitoring:

[0049] Electrical and mechanical durability tests are carried out on the prepared spiral heating wire.

[0050] Electrical property test: After testing the resistance by the four - wire method, the accuracy is ±0.1%; After the withstand voltage test, it is obtained that: AC 3000V / 5mA, no breakdown in 60 s;

[0051] Mechanical durability test: Bending test: According to the ISO 19642 standard, after 50,000 bends, the resistance change rate ≤ 5%; After the tensile test, it is obtained that: the breaking strength ≥ 150 N (for 0.35 mm 2 wire).

[0052] Infrared thermal imaging shows that when the spiral heating wire of the vehicle seat prepared by the above method is used, the temperature difference on the seat surface ≤ 1.5 °C; And the bending test life reaches 120,000 times, which is 50% higher than the traditional design with a bending life of 60,000 times, and the resistance change rate also drops from the traditional 8% to 3%. Applying the spiral heating wire of the present invention to the heating seat of a new energy vehicle model for testing, the test conditions are:

[0053] In an environment of -30°C, heat continuously for 30 minutes. The results show that it only takes 8 minutes for the surface temperature of the seat to rise from -30°C to 35°C, and the energy consumption is reduced by 18%.

[0054] The spiral heating wire for a vehicle seat provided by the present invention has the following beneficial effects:

[0055] (1) On the one hand, the present invention adopts a spiral winding method, which increases the contact area between the wire and the seat fabric by more than 50%. Moreover, the spiral gaps form micro airflows, accelerating heat diffusion and improving the heat transfer efficiency. On the other hand, the spiral heating wire provided by the present invention can achieve a temperature difference on the seat surface ≤ 1.5°C, solving the problems of poor temperature control uniformity and uneven heat in traditional vehicle seat heating wires, which are prone to poor temperature control during use, resulting in temperature rise and bringing an unpleasant experience to passengers.

[0056] (2) During the process of the seat heating wire of the present invention, first, it is treated by an annealing process. Under a hydrogen protection atmosphere, it is heated to 800°C at a rate of 10°C / min, held for 30 minutes, and then slowly cooled. The internal stress is eliminated, and the resistivity volatility also drops from the traditional 5% to 1.5%, further reducing the change in resistivity, avoiding obvious temperature fluctuations, and reducing energy consumption.

[0057] (3) The present invention uses a conductor material made of nickel-chromium alloy, and the resistance stability is increased by 20%. At the same time, the central filling material selects basalt fiber rope with high tensile strength and high temperature resistance, and the insulating layer material selects XLPVC or XLPE with high temperature resistance and high insulation resistance. Compared with traditional heating wires, the service life is increased from 60,000 times to 120,000 times, and the overall bending resistance life is increased by 50%. This significantly improves the performance of the heating wire; combined with intelligent manufacturing processes, it realizes high consistency and low energy consumption production; integrated intelligent temperature control technology lays a foundation for future vehicle networking applications.

[0058] Although the specific embodiments of the present invention have been described above, those skilled in the art of this technology should understand that the specific embodiments we described are illustrative only and not used to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should all be covered by the scope protected by the claims of the present invention.

Claims

1. A spiral heating wire for a vehicle seat, characterized in that: It includes, from the inside to the outside in sequence: a reinforced filling layer, a cushion layer, a metal wire, an adhesive layer and an insulating layer; The reinforced filling layer is made of basalt fiber ropes; The cushion layer is made of nylon or fluoroplastics; The metal wire is made of nickel-chromium alloy and is spirally wound around the cushion layer, with a spiral diameter of 23 mm and a pitch of 4 mm; The insulating layer is XLPVC or XLPE.

2. The spiral heating wire of a vehicle seat according to claim 1, characterized in that: The adhesive layer is made of EVA resin.

3. The preparation method of a spiral heating wire for a vehicle seat according to claim 1, characterized in that: It includes the following steps; Step 1: Core wire processing: It includes: a wire drawing process and an annealing treatment; The specific wire drawing process is: using a multi-mode continuous wire drawing machine, drawing with a die aperture tolerance of ±0.001 mm, and real-time monitoring of the diameter fluctuation by an on-line laser diameter gauge to ensure the resistance consistency; The specific annealing treatment is: heating to 800 °C at a rate of 10 °C / min in a hydrogen protection atmosphere, holding for 30 min and then slowly cooling; Step 2: Spiral winding: Using a high-precision servo motor with a positioning accuracy of ±0.01 mm and a tension control system with a fluctuation of ≤±0.1 N for winding, and based on PID feedback adjustment, dynamically compensating for the elastic deformation of the material to ensure that the pitch error is ≤±0.05 mm; Step 3: Insulating coating: Adopting a double-layer co-extrusion die head, the inner layer is an adhesive layer made of EVA resin material, and the insulating layer is XLPVC or XLPE; then irradiation cross-linking is carried out, and the cross-linking degree is ≥75%; Step 4: Quality monitoring: Conducting electrical property tests and mechanical durability tests on the prepared spiral heating wire.

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