AUTOMOTIVE LAMINATE WITH EMBEDDED WIRE CIRCUIT

Abstract

Laminated glazings with embedded wire circuits, have many uses. But, due to the higher cost of manufacture, they are not widely used. This invention provides a process to reduce the cost of production for embedded wire laminated glazing. Rather than embedding the wire one interlayer at a time, several circuits are produced on the same sheet, cut out and then inserted into the interlayer of each separate laminate during assembly, reducing the direct labor and capital investment required.

Claims

1. A process for manufacturing a laminated windshield with embedded circuits; comprising the steps of: embedding conductors for multiple circuits on a sheet of interlayer; cutting and separating said circuits from said sheet; cutting openings in the interlayer for a single laminate sheet; placing said circuits into opening in said single laminate sheet; and applying heat and pressure to said laminate.

2. The process of claim 1 comprising the step of splicing said circuit to said single laminate sheet.

3. The process of claim 1, wherein the circuit is selected from the group consisting of resistive heating circuit, antenna circuit, rain sensing circuit, power supplying circuit, occupant sensing circuit, data transmitting circuit, touch sensitive circuit, lighting circuit and control signal circuit.

4. The process of claim 1, wherein the circuit includes comprising tungsten wire in the range of about 9 microns to about 125 microns.

5. The process of claim 1, wherein the circuit includes tungsten wire in the range of about 9 microns to about 75 microns.

6. The process of claim 1, wherein the circuit includes comprising copper wire in the range of about 20 microns to 250 microns.

7. A laminated glazing comprising at least one circuit produced by the process of claim 1.

8. The laminate glazing of claim 7 comprising a PVB interlayer.

9. A vehicle comprising the laminate glazing of claim 7.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0041] These features and advantages of the present invention will become apparent from the detailed description of the following embodiments in conjunction with the accompanying drawings, wherein:

[0042] FIG. 1A shows a laminated windshield with embedded wire camera area and HWA defrosters.

[0043] FIG. 1B shows an interlayer with embedded wire camera area and HWA defrosters for windshield of FIG. 1A.

[0044] FIG. 2A shows a camera area defroster circuit cross section.

[0045] FIG. 2B shows a camera area defroster circuit.

[0046] FIG. 3 shows an interlayer sheet with multiple camera defroster circuits.

[0047] FIG. 4 shows an interlayer sheet with multiple camera HWA circuits.

[0048] FIG. 5 shows an interlayer sheet with multiple camera HWA circuits.

[0049] FIG. 6A shows an interlayer with embedded cut out for wire camera area and for HWA defrosters for windshield of FIG. 1.

[0050] FIG. 6B an interlayer with embedded cut outs for wire camera area and HWA defrosters for windshield of FIG. 1.

[0051] FIG. 7A shows an interlayer with embedded wire camera area and HWA defrosters for windshield of FIG. 1.

[0052] FIG. 7B shows an interlayer with embedded wire camera area and HWA defrosters for windshield of FIG. 1.

REFERENCE NUMERALS

[0053] 2 Glass

[0054] 4 Interlayer

[0055] 5 Wire

[0056] 8 Heated wiper area defroster

[0057] 10 Camera defroster

[0058] 12 Bus bar

[0059] 14 Cut

DETAILED DESCRIPTION OF THE INVENTION

[0060] The cost of the conventional process of embedding wire is driven by the low throughput and resulting high capital, floor space and labor required.

[0061] In the case of a heated windshield, where substantially all of the surface area must have wire embedded, consuming several hundreds of meters of wire, the one at a time approach is the only way to make the circuit on an XY type machine. Multiple full windshields circuits can be produced on a CNC machine that operates in a manner similar to that of a lathe. The interlayer is wrapped around a large (1.5 m diameter) drum, bus bars are applied to the interlayer, and the wire is embedded as the drum spins. While this works well for these types of circuits, it is not possible to make the more complex circuits required for the camera and HWA.

[0062] On a windshield having both a camera and a HWA, the total heated area is less than 10% of the windshield surface area. The camera area is in the range of 1 to 2 decimeters squared or less than 2% of the typical 1.5 square meter windshield. Only 2-4 meters of wire are needed. The HWA is larger but still only need cover the area from just below the wipers to just about the area heated by the hot air blower system. A large HWA would be in the range of 5-10 square decimeters or 3.5% to 7% of the surface area and uses just 10-20 meters of wire.

[0063] FIG. 1A shows a windshield having both a camera 10 defroster and an HWA 8. FIG. 1B shows the interlayer of the prior art with the embedded wire circuits prior to lamination. Note that the black paint covers and hides the bus bars on each circuit.

[0064] When processing interlayers for parts with camera 10 and/or HWA 8 circuits, one sheet at a time, up to 90% of the cycle time is taken up by placing and locating the sheet of interlayer 4 on the machine and then removing and stacking off after the wire has been embedded. Part to this is due to the large size and the soft, limp composition of the interlayer 4 which makes them difficult to handle.

[0065] If both an HWA 8 and a camera 10 defroster are needed a tool change over must be made. Due to the differences between the sizes of the two circuits, they will rarely be able to use the same wire and sometimes not even the same bus bar.

[0066] By producing multiple copies of each circuit on separate sheets of interlayer, and then combining the circuits with the larger sheet during assembly of the laminate just prior to the autoclave, these disadvantages are greatly reduced. This method also enables the use of less expensive machines with smaller beds.

[0067] It should be noted that the embedded wire circuit could have functionalities as the followings: a resistive heating circuit, an antenna circuit, rain sensing circuit, power supplying circuit, occupant sensing circuit, data transmitting circuit, touch sensitive circuit, lighting circuit, control signal circuit among others.

DESCRIPTION OF EMBODIMENTS

[0068] Referring to FIG. 1A, in an embodiment of the invention, a 1.4 m1.2 m windshield, has a camera 10 defroster comprised of two 3 mm100 mm bus bars and 3 meters of 45 micron diameter tungsten wire, and a HWA 8 with two 6 mm100 mm bus bars and 18 meters of 80 micron copper wire. To meet demand for the laminate, a production line runs this part 24/7 at an average rate of 1 every 60 seconds for two weeks every month.

[0069] Processing one sheet at a time, a machine having an envelope of at least 1.4 m1.2 m can produce sixteen interlayers per hour as shown in Table 1. Therefore four machines are needed and must have a utilization rate of 96% to meet the demand.

[0070] Sixty of the camera 10 defroster circuits cans be embedded on a 1 square meter interlayer in 1,522 seconds and a rate of 142 per hour (see Table 2 and FIG. 3). Ten HWA 8 circuits (FIG. 4) can fit on a 1 meter sheet and can be produced at a rate of 70 per hour (Table 3). Two machines, with an envelope of 1 m1 m are needed and must have a utilization rate of just 64%.

[0071] The circuits are cut 14 and separated from the interlayer 4 sheet and then inserted into the individual laminate interlayer sheet into openings cut to fit the circuits. The assembled laminate is then processed in the same as a standard laminate with heat and pressure applied in an autoclave.

[0072] With a larger machine, 1 m1.2 m, the HWA 8 along with the entire bottom portion of the interlayer 4 can be produced and then spliced to the shorter interlayer sheet at assembly. This is advantageous when a more expensive performance (wedge, solar control, sound deadening, etc.) interlayer 4 required. There is no need for the performance interlayer 4 in the areas of the laminate that are obscured by black paint and the splice is also obscured.

[0073] Eight HWA circuits can fit on a 1 m1.2 m sheet of interlayer 4 as shown in FIG. 5. They can be produced at a rate of 66 per hour (Table 4). Two machines must be operated at a utilization rate of 67%.

[0074] In both cases, the capital investment is reduced by replacing four larger machines with two smaller machines. Clean room floor space is saved by reducing the foot print by using fewer and smaller machines as is the storage space required for work in process embedded wire interlayers. One additional person is required during assembly to splice the interlayer but this added labor is offset by the reduction in labor in the wire embedding process.

TABLE-US-00001 TABLE 1 Operation Meters Seconds Load 60 Tool Change 20 Camera Bus bars 0.2 10 Tool Change 20 HWA Bus bars 0.2 10 Tool Change 20 Camera Wire 3.0 13 Tool Change 20 HWA Wire 18.0 28 Unload 30 Total 231 #/hour 16

TABLE-US-00002 TABLE 2 Per Sheet 60 Operation Meters Seconds Seconds Load 60 Tool Change 20 20 Camera Bus bars 0.2 10.2 612 Tool Change 20 20 Camera Wire 3 13 780 Unload 30 30 Cycle Time 1,522 Each 25 #/hour 142

TABLE-US-00003 TABLE 3 Per Sheet 10 Operation Meters Seconds Seconds Load 60 Tool Change 20 20 HWA Bus bars 0.2 10.2 102 Tool Change 20 20 HWA Wire 18 28 280 Unload 30 30 Cycle Time 512 Each 51 #/hour 70

TABLE-US-00004 TABLE 4 Per Sheet 8 Operators Meters Seconds Seconds Load 60 Tool Change 20 20 HWA Bus bars 0.2 10.2 82 Tool Change 20 20 HWA Wire 18 28 224 Unload 30 30 Cycle Time 436 Each 54 #/hour 66