JP4782635B2 - Steering wheel heater - Google Patents

Description

  The present invention relates to a steering wheel heater that covers and warms the entire circumference of a steering wheel, and more particularly to a steering wheel heater that can freely determine the position of a power supply electrode.

  Automobile steering wheel heaters (heaters used in steering wheels for changing the direction of travel of automobiles) have become widespread as comfortable equipment in cold regions. Most of the steering wheels equipped with this heater are mainly leather-wrapped. Specifically, as shown in FIG. 6, a core material (not shown) formed in a ring shape, a ring portion 61 that covers the periphery of the core material with synthetic resin, and a substantially central position of the ring portion 61 are arranged. A boss portion 62, a spoke portion 63 that extends from the inner diameter side of the ring portion 61 toward the boss portion 62 and joins the ring portion 61 and the boss portion 62, and a planar heating element 50 ( 7) and a skin portion 64 that covers the periphery of the ring portion 61 covered with the planar heating element 50 with leather, and can warm the entire circumference of the steering wheel. The planar heating element 50 is used to cover the periphery of the ring portion 61 of the steering wheel 60 so that it does not lose its shape with elasticity and flexibility when it is brought into close contact with the ring portion 61. Because.

  As such a planar heating element 50, for example, a mesh heater as shown in FIG. 7A is disclosed (for example, see Patent Document 1). The mesh heater 50 is provided with power supply electrodes 53 and 54 in a state of being separated by one end portions 52a and 52b in one direction of a mesh heating element 52 in which a plurality of heater wires 51 are knitted in a mesh shape. ing. The mesh-like heating element 52 is formed by tricot knitting that continuously and planarly passes through the loop in the warp direction. Therefore, as shown in FIG. 7B, the mesh heater 50 is composed of a plurality of electrically independent heater wires 51 arranged in parallel and having both ends 52a and 52b connected by electrodes 53 and 54. is there. Since the heater wires 51 are insulated from each other, a simple parallel circuit can be obtained by solving the mechanical entanglement. The heater wire 51 is made of an alloy wire having a stable resistance so that appropriate heat generation is obtained at a voltage value of 12 volts used as a power source for automobiles and the resistance value does not change with time. Has been.

  Further, when a heater is disposed on the steering wheel, the position of the power feeding electrode and the lead wire drawing position are important. Specifically, as shown in FIG. 6, the position of the steering wheel 60 with a low probability that the driver touches each of the power feeding electrodes 53 and 54, for example, the rotational position of the steering wheel 60 is straight in the traveling direction of the automobile. It arrange | positions in the lower part 60a in the case of. In order to make the lead wires 55 and 56 fixed to the power feeding electrodes 53 and 54 as inconspicuous as possible, the skin portion 64 covering the periphery of the ring portion 61 from the lower portion 60a of the steering wheel 60 is provided. The spoke portion 63 is wired along the inner side, and the spoke portion 63 is wired to the boss portion 62 and connected to a power supply terminal (not shown).

JP 2003-123947 A

  However, in such a mesh heater 50, the positions of the feeding electrodes 53 and 54 are limited to the both ends 52 a and 52 b of the mesh heating element 52, so that the lead wires 55 and 56 are the ring portions 61 of the steering wheel 60. Will be placed. Therefore, the texture of the leather-wrapped steering wheel is impaired, and there is a risk that the driver may see irregularities that can be seen when a heater is disposed on the steering wheel. In order to avoid such difficulties, it is possible to make the ring portion 61 and the two spoke portions 63, 63 grooved or embedded in order to make the lead wires fold, but the manufacturing cost is reduced. It becomes one factor to raise. In addition, since the power feeding electrodes 53 and 54 of the mesh heater 50 substantially cover the outer diameter in the cross-sectional direction of the ring portion 61, there is a difficulty in disposing at the position of the spoke portion 63 in the ring portion 61.

  The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide a steering wheel heater that can freely set the position of a power feeding electrode regardless of the shape of the steering wheel. .

  The principle of the present invention is that a mesh heating element knitted with insulated heater wires is electrically separated into two in a direction perpendicular to the warp knitting direction, and either one of the separated mesh heating elements is used. Are separated in the warp knitting direction, and the two separated ends of one mesh heating element separated in the warp knitting direction are used as power feeding electrodes, so that the position of the power feeding electrode is changed to that of the mesh heating element. It is to be able to set freely in the knitting direction. In such a configuration, since the resistance value of the mesh heating element is always constant even if the position of the electrode changes, the amount of heat generation can also be made constant.

A first aspect of the present invention is a mesh in which a plurality of insulated heater wires are warp knitted and provided with first electrodes in a state of being spaced at both ends in the warp knitting direction, which is a direction in which a loop is bound. In the heater for a steering wheel that is provided so as to cover the entire circumference of the ring portion of the steering wheel, the mesh heating element is electrically connected to the mesh heating element in a direction orthogonal to the warp knitting direction. Any one of the insulating part composed of the two insulated wires and the mesh heating element electrically separated into two by the insulating part is separated in the warp knitting direction. Provided with a second electrode for power feeding, and one mesh heating element and the other separated mesh heating element are electrically connected in series by two first electrodes and two second electrodes. One of the two second electrodes connected In which power from the electrode is supplied.

  According to the steering wheel heater of the present invention, the position of the power feeding electrode can be freely set in the warp knitting direction of the mesh heating element while keeping the resistance value of the mesh heating element constant. Therefore, the position of the power feeding electrode can be freely set regardless of the shape of the steering wheel, so that the lead wire drawing position can be limited to the spoke portion.

  A preferred embodiment to which the steering wheel heater of the present invention is applied will be described below with reference to the drawings.

  A steering wheel in which the heater for a steering wheel of the present invention is used, for example, as shown in FIG. 4A, a core material 2 formed in a ring shape, a ring portion 3 in which the core material 2 is covered with a synthetic resin, The boss part 4 is arranged at a substantially central position of the ring part 3, and the spoke part 5 extends from the inner diameter side of the ring part 3 toward the boss part 4 and joins the ring part 3 and the boss part 4. Yes. The steering wheel 6 is for automobiles, and the front wheels can be steered by incorporating the boss portion 4 into a steering shaft (not shown). The steering wheel heater of the present invention is arranged so as to cover the periphery of the boss portion 4.

  For example, as shown in FIGS. 1 and 4B, the steering wheel heater 1 according to the present invention has a plurality of insulated heater wires 11 warped, and both ends 12A in the warp knitting direction V, which is a direction in which a loop is bound. , 12B and the net-like heating element 12 provided with the first electrodes 13A and 13B, and the mesh-like heating element 12 are electrically separated into two in the direction H perpendicular to the warp knitting direction V. Among the two mesh-like heating elements 12a and 12b separated by the insulation part 10, for example, the mesh-like heating element 12a is separated in the warp knitting direction V. Second electrodes 14A and 14B for power feeding are provided. Therefore, for example, when power is supplied from the second electrode 14A, the current flows from the first mesh heating element 12aa → the first electrode 13A → the second mesh heating element 12b → the first electrode 13B → the third. Since the second mesh heating element 12ab and the second electrode 14B flow, the first mesh heating element 12aa, the second mesh heating element 12b, and the third mesh heating element 12ab are the second electrode 14A and the second electrode 14A. The first electrode 13A, the first electrode 13B, and the second electrode 14B are connected in series. The first electrodes 13A and 13B electrically connect all of the plurality of heater wires 11 of the mesh heating element 12, and the second electrodes 14A and 14B are electrically separated of the mesh heating element 12a. All of the plurality of heater wires 11 are electrically connected. The second electrodes 14A and 14B are connected to the connection terminal 16 via lead wires 15, respectively.

  As shown in FIG. 2, the mesh heating element 12 includes a plurality of heater wires 11 having a single wire diameter formed by, for example, tricot knitting. In order to reduce the cost, the heater wire 11 of the mesh-like heating element 12 uses a commercially available enameled wire in which the wire diameter is single and the heater bare wire made of substantially copper is coated with the enamel wire paint. Although the heater bare wire may be a copper alloy containing 1% or more of nickel, or an alloy resistant to corrosion such as a nichrome wire. The selection of the material of the heater wire 11 is set according to the heat generation amount per unit area of the mesh heating element 12.

  The enamel wire paint is applied and baked on the bare bare wire to form an insulating film. As the enamel wire coating material, a material mainly composed of polyvinyl acetal, polyurethane, polyamideimide or polyimide is preferable. The enameled wire paint based on polyvinyl acetal or polyurethane has a heat resistance of 100 to 150 ° C., and can be soldered without peeling off the film. Can consist of time. In addition, the enameled wire paint mainly composed of polyamideimide or polyimide has high heat resistance and good wear resistance, so that tricot knitting is easy. According to such enamel wire paint, (1) insulation can be ensured with a very thin uniform film. For example, in the case of a metal conductor having a wire diameter of 0.07 mm, the minimum film thickness is JIS type 3 enamel wire. The outer diameter of the heater wire does not become larger than necessary, (2) can withstand severe mechanical bending during braiding, and (3) a heat-resistant clade as necessary. It can be selected from a wide range, and except for special ones, it can be selected from 105 to 240 ° C. in the UL standard.

  When the wire diameter of the heater element wire 11 in which the bare heater wire is coated with the enamel wire paint is 0.02 to 0.12 mm, preferably 0.06 to 0.08 mm, the strength and flexibility are improved. Both can be achieved. Accordingly, a heater wire that is thinner and more flexible can be provided. Therefore, if the plurality of heater wires 11 are bound so that the loop is continuous in the warp direction, a mesh-like heat generation that is rich in elasticity and flexibility is provided. The body 12 can be provided.

  As shown in FIGS. 3A and 3B, the first electrodes 13A and 13B and the second electrodes 14A and 14B are planar with the end portions of a predetermined number of heater wires 11 superimposed on the metal foil 17, respectively. The electrode base layer 18 is soldered in a thin state, and the insulating material 19 is adhered to the electrode base layer 18 so as to cover both front and back surfaces.

  The metal foil 17 forming the electrode base layer 18 is a rectangular shape having a predetermined width and length, and has a thickness of 0.01 mm to 0.5 mm, and has conductivity and corrosion resistance, such as tin and solder. Alternatively, a non-ferrous metal such as gold is preferably subjected to a film treatment such as plating. The same effect can be obtained even if the metal foil itself is made of a non-ferrous metal such as gold, silver or nickel having conductivity and corrosion resistance. Soldering is performed on a planar heating element 12 stacked on the metal foil 17 with a heated soldering iron in a planar state thinner than the thickness of the metal foil 17 on one surface of the metal foil 17. The thickness of this solder is preferably 5 μm to 30 μm. As such solder that can be soldered, a solder with a high flux content, good high temperature characteristics, and excellent wettability is preferable. The solder is preferably lead-free solder such as tin-silver-copper or tin-silver-bismuth from the viewpoint of environmental protection.

  The insulating material 19 is preferably a non-woven fabric such as a polyester-based fiber that has been subjected to a flame retardant treatment, is rich in elasticity, and has flexibility, such as heat-resistant polyester fibers. Moreover, as an adhesive for adhering the insulating material 19 to the electrode base layer 18, silicon, flame retardant acrylic, thermosetting rubber, or the like is preferable from the viewpoint of flame retardancy and heat resistance. Moreover, as an insulating material other than the nonwoven fabric, a flame retardant nomex adhesive tape, a flame retardant cloth adhesive tape, a polyimide tape, a fluororesin tape, and the like are suitable. Furthermore, the electrode base layer 18 is sealed with a waterproof polymer film and then covered with the insulating material 19, whereby a highly waterproof electrode structure can be obtained.

  Although not shown in the drawings, the stitches formed at both ends in the other direction of the mesh-like heating element not provided with electrodes are bordered by heat-resistant synthetic fiber yarns so that they cannot be unwound. It is overburdened. Thereby, since the expansion and contraction more than necessary in the warp direction V, which is the direction in which the loop of the mesh-like heating element 12 is bound, can be prevented, the deformation of the mesh-like heating element 12 can be prevented.

  As shown in FIG. 4C, the steering wheel heater 1 is disposed so as to cover the entire circumference of the ring portion 3 of the steering wheel 8. At this time, the heater 1 is fixed to the ring portion 3 with a double-sided tape or an adhesive. And since the heater 1 fixed in the state which covered the ring part 3 is covered with leather, and this leather becomes the skin part 7, it becomes a leather-wrapped steering wheel which raises a high-class feeling. Further, each lead wire 15 connected to the second electrodes 14A and 14B is built in the spoke portion 5 without turning on the circumference of the ring portion 3, and the connection terminal 16 connected to each lead wire 15 is connected to the power source. Connected to a terminal (not shown).

  As shown in FIG. 1, the mesh heating element 12 includes at least one heater element wire 11 ′ (in the drawing) at a position where the mesh heating element 12 is electrically separated. The insulating portion 10 may be obtained by changing the color of the broken line) from the color of the other heater wire 11. Since the insulating portion 10 must be composed of an insulated wire, the heater element wire 11 'becomes an insulated wire by not being connected to any electrode in order to electrically isolate the mesh heating element 12. Thereby, since the division | segmentation position of a mesh-shaped heat generating body can be visually recognized easily, it becomes easy to fix a division | segmentation electrode. That is, it becomes a standard for separating a plurality of heater wires, and an operational error can be prevented.

  Further, as shown in FIG. 1, the mesh heating element 12 includes at least one heater element wire 11 ′ (in the drawing) at a position where the mesh heating element 12 is electrically separated. The insulating portion 10 may be made of an insulating wire by using an insulating material for the broken line. As a result, the wires with voltage applied do not directly contact each other, and the risk of electrical breakdown (short circuit) is reduced. Since the heater wire 11 'is an insulating material, it is not energized even if it is connected to the electrode. Note that the number of insulating materials is limited within a predetermined error range of the resistance value. Considering the usage environment of the mesh heating element, the insulating material may be a fiber having heat resistance of about 100 ° C., such as polyester, nylon, kevlar, cotton thread, hemp, and the like.

  When the overall length of the steering wheel heater 1 is L, the mesh heating elements 12a (12aa, 12ab) and 12b are connected in series. Therefore, the two mesh heating elements 12a and 12b are connected to each other. The total length is 2L. Therefore, since the total length is L regardless of where the separation position is provided in the warp knitting direction V in the mesh-like heating element 12a, the combined resistance value of the two mesh-like heating elements 12a and 12b also depends on where the separation position is in the warp knitting direction V. Even if it is provided, it will be the same. In addition, since the net-like heating element 12a is separated in the warp knitting direction V, the total length is slightly shorter than that of the mesh-like heating element 12b.

  Further, as shown in FIG. 5, a second electrode 14C is provided at the other end without separating the mesh-like heating element 12b provided with the first electrode 13A at one end, and the second electrode 14C and the first electrode Even if the electrode 13B is used as a power feeding electrode, the entire length of the mesh heating element 12a can be made L. Therefore, the total length of the two mesh heating elements 12a and 12b is 2L. In this case, for example, when power is supplied from the second electrode 14C, the current flows in the order of the first mesh heating element 12a → the first electrode 13A → the second mesh heating element 12b → the first electrode 13B. Therefore, the first mesh heating element 12a and the second mesh heating element 12b are connected in series by the second electrode 14C, the first electrode 13A, and the first electrode 13B.

  As described above, in the steering wheel heater according to the present invention, the positions of the two electrodes for power feeding can be freely set, so that the lead wire drawing position can also be freely set. Therefore, there are two types of spoke portions of the steering wheel, three or four, and the spoke position is often different for each steering wheel, but the same applies to any steering wheel. Even if the mesh heating element is used and the positions of the two electrodes for power feeding are freely set, the resistance value of the entire mesh heating element can always be stabilized.

  Although the present invention has been described with the specific embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and is known so far as long as the effects of the present invention are achieved. It goes without saying that any configuration can be adopted.

It is explanatory drawing which shows the example of preferable embodiment in the heater for steering wheels of this invention. The pattern figure in case the mesh-like heat generating body which is a component of the heater for steering wheels of this invention is a tricot knitting. It is a figure which shows the electrode which is a component of the heater for steering wheels of this invention, (A) is explanatory drawing of soldering, (B) is sectional drawing of an electrode. It is a figure which shows the application state of the heater for steering wheels of this invention, (A) is a top view of a steering wheel, (B) is a top view of a heater, (C) is explanatory drawing of the state with which the heater was mounted | worn to the steering wheel. is there. It is explanatory drawing which shows other preferable embodiment of the heater for steering wheels of this invention. It is explanatory drawing of the state which mounted | wore the steering wheel with the conventional heater for steering wheels. It is a figure of the knitted mesh heater, (A) is a block diagram, (B) is explanatory drawing which shows that a mesh heater is a parallel circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Heater for steering wheels 11 ... Heater strand 11 '... Heater strand used as an insulating wire 12 ... Mesh heating element 12a, 12b ... Mesh heating element 13A, 13B separated into two ... ... 1st electrode 14A, 14B, 14C ... 2nd electrode 17 ... Metal foil 18 ... Electrode base layer 19 ... Insulating material

Claims (5)

A mesh-like heating element in which a plurality of insulated heater wires are warp knitted and spaced apart at both ends in the warp knitting direction, which is the direction in which the loop is bound, provided with the first electrodes (13A, 13B) ( 12), and a steering wheel heater arranged to cover the entire circumference of the ring portion (3) of the steering wheel (6),
The mesh heating element is
An insulating portion (10) comprising an insulating wire that electrically separates the mesh-like heating element into two in a direction (H) orthogonal to the warp knitting direction (V);
Any one of the mesh-like heating elements (12a, 12b) electrically separated by the insulating portion is separated in the warp knitting direction, and the power supply for power supply provided at each of the two separated ends is provided. A second electrode (14A, 14B),
The one mesh heating element (12b) and the other separated mesh heating element (12aa, 12ab) are electrically connected in series by the two first electrodes and the two second electrodes. And a power supply for supplying power from one of the two second electrodes .   2. The heater for a steering wheel according to claim 1, wherein the mesh-like heating element is formed by tricot knitting in which the plurality of heater wires are continuously and planarly bound in the warp direction. 3.   The heater for a steering wheel according to claim 1 or 2, wherein the insulated wire is different in color from the heater wire.   The steering wheel heater according to any one of claims 1 to 3, wherein the insulating wire is a heat-resistant fiber.   The electrode is bonded to an electrode base layer that is soldered in a thin and flat state by overlapping a predetermined number of ends of the heater wires on a rectangular metal foil, and covering both front and back surfaces of the electrode base layer. The steering wheel heater according to any one of claims 1 to 4, wherein the heater is made of a flexible insulating material.

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