JP2006032137A - Lighting fixture for vehicle and manufacturing method of lighting fixture for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain appearance and performance of a thin-film heater in good order by preventing a conductive heating element from being deformed or cut off by fluid pressure at injection of a material resin of a lens, or from being stuck to a die or being oxidized. <P>SOLUTION: The manufacturing method of a lighting fixture for a vehicle 10, integrally forming a thin-film heater 40 on a lens 30 covering the front face of a lighting room 22 with a light source 4, comprises a process of forming a thin-film heater by pinching the conductive heating element 41 with two resin sheets 42, 43, and a process of molding the lens by injecting the material resin into a cavity 71 of the die 70 with the above thin-film heater positioned in the cavity and integrating the thin-film heater with the lens. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a novel vehicle lamp and a method for manufacturing a vehicle lamp. More specifically, the present invention relates to a technique for improving the moldability of a heater-integrated lens and maintaining the appearance and performance of the heater in a vehicular lamp in which a heater is integrally provided on a lens for snow melting and anti-fogging.

  For example, Patent Document 1 discloses a vehicular lamp in which a heater is integrated with a lens for the purpose of melting snow adhering to the lens or eliminating fogging of the lens.

  In the vehicular lamp of Patent Document 1, an FPC heater formed by forming a conductive foil pattern on a resin base film by a printing method is inserted into a cavity of a lens molding die. The lens material resin is injected, and the FPC heater is integrated with the lens simultaneously with the molding of the lens.

Japanese Patent Laid-Open No. 10-109587

  By the way, in the vehicular lamp shown in Patent Document 1 described above, when the material resin of the lens is injected into the cavity, the material resin flows along the conductive foil pattern of the FPC heater, Since the flow pressure is considerable, there is a problem that the conductive foil is peeled off from the base film and the pattern is deformed, or in the worst case, the conductive foil is cut.

  In order to prevent peeling or cutting of the conductive foil of the FPC heater due to the flow pressure of the lens material resin described above, when inserting the FPC heater into the cavity, the conductive foil is not a flow side of the material resin but a mold. Although it is conceivable to arrange in a direction in contact with the surface, there is a problem that the conductive foil of the FPC heater is pressed against the mold surface by the flow pressure of the material resin and damages the mold surface. Further, since the mold surface becomes high temperature, the conductive foil may stick to the mold surface. And when attached to the lamp, the conductive foil oxidizes to touch the outside air and the resistance value changes, or the color of the conductive foil changes, it loses the desired color, and it looks bad There's a problem.

  Therefore, the present invention improves the appearance and performance of the thin film heater by preventing the conductive heating element from being deformed or cut by the flow pressure at the time of injection of the lens material resin, or sticking to the mold or oxidizing. The problem is to keep it good.

  In order to solve the above-described problems, a method for manufacturing a vehicular lamp according to the present invention includes a step of forming a thin film heater by sandwiching a conductive heating element between two resin sheets, and the thin film heater as a cavity of a mold. A step of injecting a material resin into the cavity in a state of being positioned inside, forming a lens, and integrating the thin film heater with the lens.

  In order to solve the above-described problems, the vehicle lamp according to the present invention is provided with a thin film heater integrally with the lens, and the thin film heater sandwiches a conductive heating element between two resin sheets. It consists of

  Therefore, in the present invention, since the conductive heating element is sandwiched between the two resin sheets, it does not directly receive the flow pressure of the lens material resin.

  The method for manufacturing a vehicular lamp according to the present invention is a vehicular lamp manufacturing method in which a thin film heater is integrally formed on a lens that covers a front surface of a lamp chamber in which a light source is disposed, and the conductive heating element is formed of two resin sheets. Forming a thin film heater by sandwiching them, and injecting a material resin into the cavity in a state where the thin film heater is positioned in the cavity of the mold, forming a lens, and forming the thin film heater on the lens It is characterized by comprising a step of integrating the above.

  Further, the vehicle lamp according to the present invention is a vehicle lamp provided with a resin lens that covers a front surface of a lamp chamber in which a light source is disposed, and the thin film heater is integrally provided on the lens. The conductive heating element is sandwiched between two resin sheets.

  Therefore, in the present invention, since the conductive heating element is sandwiched between the two resin sheets, it does not directly receive the flow pressure of the lens material resin. Therefore, when the lens material resin is injected, the conductive heating element is not deformed or disconnected, and the conductive heating element is not in direct contact with the mold surface. Even when mounted on the lamp, the conductive heating element does not oxidize by touching the outside air. Therefore, the conductive heating element keeps the pattern as it is formed as a thin film heater, and the resistance value does not change and the appearance does not deteriorate. Therefore, the appearance and performance of the thin film heater are kept good.

  In the invention described in claim 2 and claim 5, since the thin film heater has a terminal extending from the conductive heating element to the outside of the resin sheet, a process such as holding to a mold during the injection molding of the lens is performed. It becomes unnecessary and the process of injection molding of the lens is simplified.

  In the invention described in claim 3, since the conductive heating element is formed by laying a metal wire on the resin sheet, it is possible to apply the conductive heating element to the resin sheet with a simple device. I can do it.

  The best mode for carrying out the vehicular lamp and the vehicular lamp manufacturing method of the present invention will be described below with reference to the accompanying drawings. In the illustrated embodiment, the present invention is applied to an automotive headlamp.

  The automotive headlamp 10 is not shown in a lamp chamber 22 defined by the lamp body 20 and the lens 30, with the front opening of the lamp body 20 having a recess 21 opening toward the front covered by the lens 30. A light source 24 is attached to a reflector 23 that can be tilted by a support mechanism. As the light source 24, a cold light source such as a metal halide (HID) lamp or a light emitting diode (LED) is used, but an incandescent bulb such as a halogen bulb may be used.

  A thin film heater 40 is integrally formed on the inner surface of the lens 30. The thin film heater 40 is formed by sandwiching a conductive heating element 41 between two resin sheets 42 and 43. The resin sheets 42 and 43 have a heat resistant temperature of about 70 ° C. and may be any transparent resin sheet. For example, PC (polycarbonate) or acrylic resin sheets are suitable. The conductive heating element 41 may be any wire that generates heat when energized. For example, tungsten (W), molybdenum (Mo), nickel chromium (80Ni—Cr20, etc.), copper wire, enameled wire, etc. are used. Is preferably 0.02 mm to 0.08 mm. If the conductive heating element 41 has such a wire diameter, the conductive heating element 41 is not visually recognized in the use state of the automotive headlamp 10, and the presence of the conductive heating element 41 may impair the function of the automotive headlamp 10. Absent.

  Conductive end portions 44 and 44 (only one is shown in FIG. 2) are exposed at one end portion of the thin film heater 40. The conductive end portions 44 and 44 have one end portions 44 a and 44 a respectively connected to both end portions of the conductive heating element 41, and the other end portions 44 b and 44 b are exposed to the outside of the resin sheet 43.

  The base ends of the terminal pins 45 and 45 (only one is shown in FIG. 2) are connected to the conductive ends 44 and 44 of the thin film heater 40 by soldering or the like, and a power supply cord is connected to the terminal pins 45 and 45. A connector 47 connected to a power source is connected via 46 and 46, and power is supplied to the conductive heating element 41 via the connector 47. Instead of using the connector 47, the power supply cords 46, 46 may be directly connected to the terminal pins 45, 45 by soldering or the like.

  The power supply to the thin film heater 40 can be performed not only by the method shown in FIG. 2, but also by a method as shown in FIGS.

  In FIG. 3, L-shaped terminal pins 48 and 48 are connected to the conductive end portions 44 and 44 by soldering or the like, and a connector 47 is connected to the terminal pins 48 and 48.

  4, the terminal pins 45, 45 are projected from the end of the seal leg 31 of the lens 30, and when the seal leg 31 is fitted into the seal groove 25 of the lamp body 20, The terminal pins 45, 45 are inserted through insertion holes 25a, 25a formed in the bottom of the seal groove 25 so as to protrude outside, and the connector 47 is connected to the terminal pins 45, 45 protruding outside. It is. According to the structure shown in FIG. 4, it is not necessary to draw the connector 47 and the power supply cord into the lamp chamber 22, and the connector 47 can be connected to the terminal pins 45, 45 from the outside of the lamp chamber.

  In FIG. 5, instead of the power supply cords 46 and 46 and the connector 47, a conductor portion is printed on a resin film with a conductive foil, and the conductor portion is covered with an overlay film and an FPC cord 49. A connector 49 a connected to the end of the FPC cord 49 is used, and the connector 49 a is connected to the terminal pins 45, 45 of the thin film heater 40.

  Next, a method for manufacturing the thin film heater 40 will be described.

  First, a resin sheet 42 serving as a base is prepared, an adhesive layer 42a is formed on the resin sheet 42, and a conductive heating element 41 is wired in a predetermined pattern on the adhesive layer 42a (see FIG. 6). . The wiring of the conductive heating element 41 is performed using, for example, a wiring device 50 as shown in FIG. In the wiring device 50, the conductive heating element 41 is continuously supplied to the wiring head 52 supported on the XY table 51 by the wire material supply unit 53, and the conductive heating element 41 is connected to the tip 52a of the wiring head 52. The X-direction movable portion 51a and the Y-direction movable portion 51b of the XY table 51 are individually moved in a desired direction, so that the cloth is fed. The leading end 52a of the wire head 52 is moved so as to draw a desired pattern, and at the same time, the conductive heating element 41 is sent from the leading end 52a of the wiring head 52 so that the conductive heating element 41 draws a desired pattern. Will be laid out.

  When the wiring of the conductive heating element 41 is completed, the conductive metal foil, for example, the one end portions 44a, 44a of the copper foils 44, 44 are brought into contact with both ends of the conductive heating element 41, and the remaining copper foils 44, 44 are further removed. The portion is folded outward from the end of the resin sheet 42, and in this state, another resin sheet 43 is attached to the resin sheet 42 with the conductive heating element 41 sandwiched between the resin sheet 42 (see FIG. 7). . As a result, the copper foils 44 and 44 become the conductive end portions described above.

  In the above description, the conductive heating element 41 is attached to the resin sheet 42 by the adhesive layer 42a. However, without providing the adhesive layer 42a, wiring is performed while applying heat to the conductive heating element 41. Simultaneously with the wiring, the conductive heating element 41 may be pushed into the resin sheet 42.

  Next, a sheet in which the conductive heating element 41 is sandwiched between the two resin sheets 42 and 43 is preformed into a shape that can be inserted into a lens molding die. For example, this preform heats and softens the resin sheets 42 and 43 and sucks them by a vacuum and presses them against the mold 60 (see FIG. 8), or presses them against the molds by compressed air pressure. It is carried out by so-called thermoforming that compresses between.

  The thin film heater 40 preformed by thermoforming is inserted into the cavity 71 of the mold 70 for injection molding of the lens 30 (see FIG. 9), and in this state, the material resin of the lens 30 is injected into the cavity 71. As a result, the lens 30 is molded, and at the same time, the thin film heater 40 inserted in the mold 70 is integrated with the inner surface of the lens 30.

  Then, the terminal pins 45 and 45 are connected to the conductive end portions 44 and 44 of the thin film heater 40 integrated on the inner surface of the lens 30 by soldering or the like, thereby completing the lens 30 in which the thin film heater 40 is integrated.

  In the present invention, in the thin film heater 40 inserted into the molding die 70 of the lens 30, the conductive heating element 41 is sandwiched between the two resin sheets 42 and 43. Therefore, the material resin of the lens 30 is used. Therefore, the conductive heating element 41 is not deformed or disconnected by the injection pressure of the material resin. Further, since the conductive heating element 41 and the mold surface are not in direct contact with each other, the mold surface is not damaged, and the conductive heating element 41 is exposed to the outside air when it is mounted on the lamp. Since there is nothing, it will not oxidize or discolor.

  It should be noted that the shapes and structures of the respective parts shown in the above-described embodiments are merely examples of implementations in carrying out the present invention, and these limit the technical scope of the present invention. It cannot be interpreted in a general way.

  It is suitable when a vehicle lamp, particularly a vehicle lamp equipped with a cold light source, requires snow melting and anti-fogging.

FIG. 2 shows an embodiment of the vehicular lamp according to the present invention together with FIG. 2, and is a schematic front view. It is an expanded sectional view which follows the II-II line of FIG. It is sectional drawing of the principal part which shows an example of the electric power feeding method to a thin film heater. It is sectional drawing of the principal part which shows another example of the electric power feeding method to a thin film heater. It is sectional drawing of the principal part which shows another example of the electric power feeding method to a thin film heater. It is a schematic perspective view which shows the wiring process to the resin sheet of an electroconductive heat generating body. It is a schematic sectional drawing which shows the state which pinched | interposed the electroconductive heat generating body between the two resin sheets. It is a schematic sectional drawing which shows the preform process of a thin film heater. It is a schematic sectional drawing which shows the state which inserted the preformed thin film heater in the metal mold for lens shaping | molding.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Automotive headlamp (vehicle lamp), 22 ... Light chamber, 24 ... Light source, 30 ... Lens, 40 ... Thin film heater, 41 ... Conductive heating element, 42 ... Resin sheet, 43 ... Resin sheet, 45 ... Terminal Pin (terminal), 48 ... terminal pin (terminal), 70 ... mold, 71 ... cavity,

Claims (5)

A method for manufacturing a vehicular lamp in which a thin film heater is integrally formed on a lens that covers a front surface of a lamp chamber in which a light source is disposed,
Forming a thin film heater by sandwiching a conductive heating element between two resin sheets;
A vehicle comprising: a step of injecting a material resin into the cavity in a state where the thin film heater is positioned in the cavity of the mold, and forming a lens and integrating the thin film heater with the lens. A method for manufacturing a lamp. The method for manufacturing a vehicular lamp according to claim 1, wherein a terminal extending from the conductive heating element to the outside of the resin sheet is provided in the step of sandwiching the conductive heating element between the two resin sheets. The method for manufacturing a vehicular lamp according to claim 1, wherein the conductive heating element is formed by arranging a metal wire on a resin sheet. In a vehicular lamp provided with a resin lens that covers the front surface of a lamp chamber in which a light source is arranged,
A thin film heater is integrally provided on the lens,
The thin film heater includes a conductive heating element sandwiched between two resin sheets. The vehicle lamp according to claim 4, wherein the thin film heater has a terminal extending from the conductive heating element to the outside of the resin sheet.

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