WO2025196959A1 - Vehicular glass - Google Patents

Abstract

In this vehicular glass, a plurality of heat wires extending in a prescribed direction are routed side by side in a glass plate. The glass plate has a first region and a second region which is adjacent to the first region and to which an on-vehicle device is attached. The plurality of heat wires routed in the first region are collectively guided in the second region where the number of the heat wires is lesser than that in the first region.

Description

Vehicle glass

The present invention relates to vehicle glass.

Window glass, such as the rear window of a car, is equipped with a defogger that removes fogging and frost by passing an electric current through multiple heating wires wired at intervals, causing them to generate heat.

Patent Document 1 discloses that in a vehicle window glass equipped with a defogger, a heating wire is routed around the information-transmitting area of the glass plate where on-board equipment such as a camera or sensor is attached and external information is transmitted.

Japanese Patent Application Publication No. 2023-23392

However, if the heating wire is extended and routed around the information transmission area, as in the window glass described in Patent Document 1, the resistance value of the heating wire increases by the amount of the extended wire length, reducing the current flowing through the routed heating wire and reducing heat generation performance. Furthermore, if the routed heating wire is made thicker so that the resistance value remains the same, the current flowing through the routed heating wire can be made the same current value, but the amount of heat generated per unit length of the routed heating wire decreases by the amount of the extended wire length, again reducing heat generation performance.

As such, simply extending the heating wire and routing it around the information-transmitting area reduces the heating performance of the heating wire, and reduces the defogging performance of removing fogging and frost from the information-transmitting area.

The present invention therefore aims to provide a vehicle window glass that can preferentially heat specific areas to improve defogging performance.

The present invention comprises the following configurations.
A vehicle glass in which a plurality of heating wires extending in a predetermined direction are arranged side by side on a glass plate,
The glass plate is
A first region;
a second area adjacent to the first area, in which an in-vehicle device is mounted;
and
In the second region, the plurality of heating wires arranged in the first region are concentrated and routed to a number smaller than the number in the first region.
Vehicle glass.

The present invention provides a vehicle window glass that can enhance defogging performance by preferentially heating specific areas.

FIG. 1 is a plan view of a vehicle glass according to this embodiment. FIG. 2 is an enlarged view of part A in FIG. FIG. 3 is a schematic wiring diagram of the defogger. FIG. 4 is a circuit diagram of part B in FIG. FIG. 5 is an enlarged view of part A in FIG. 1 for explaining a modified example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a plan view of a vehicle glass 100 according to this embodiment.

As shown in FIG. 1, the vehicle glass 100 according to this embodiment has a glass plate 10 that serves as the window glass of a vehicle such as an automobile, and this glass plate 10 is equipped with a defogger 30. This example illustrates the case where the vehicle glass 100 is used as the rear window glass of a vehicle.

The glass plate 10 is generally rectangular in plan view, with an upper edge 11, a lower edge 13, and left and right side edges 15, 15. The glass plate 10 is not limited to a square or rectangle, and may be any shape, such as a trapezoid or parallelogram, with each side having a curved shape. In this example, the glass plate 10 is generally trapezoidal, with both side edges 15 sloping gradually apart downward. The glass plate 10 has curved edges on both sides of the lower edge 13, and the corners between the upper edge 11 and both side edges 15 are also curved. The first glass plate 10 is not limited to a flat shape, and may have a curved shape that bulges outward toward the exterior of the vehicle. The glass plate 10 may be a single glass plate, or may be laminated glass with an intermediate layer sandwiched between a pair of glass plates.

The glass plate 10 has a light-shielding film 21. This light-shielding film 21 is made of a dark ceramic print, for example, black, and is printed on the interior surface of the glass plate 10. The light-shielding film 21 is provided along the outer edge of the glass plate 10. By providing this light-shielding film 21, the adhesive points of the glass plate 10 to the vehicle window frame are covered by the light-shielding film 21, making them invisible from outside the vehicle.

The glass plate 10 has a wiper mounting portion 17 at the center of its lower part, and the pivot shaft (not shown) of the rear wiper is located at this wiper mounting portion 17. The light-shielding film 21 bulges upward at the center in the vehicle width direction along the lower edge 13 of the glass plate 10, and the wiper mounting portion 17 is located at this bulging portion of the light-shielding film 21.

FIG. 2 is an enlarged view of part A in FIG.
As shown in FIG. 2 , the glass plate 10 has a first region A1 and a second region A2 adjacent to each other. The first region A1 is an area inside the light-shielding film 21. The second region A2 is provided in the upper center of the glass plate 10 and is adjacent to the first region A1. The upper center of the glass plate 10 is covered with the light-shielding film 21, and the second region A2 is provided in the portion covered by this light-shielding film 21. This second region A2 has an area where the light-shielding film 21 has been removed, and this area is designated as a transmissive region At. In other words, the first region A1 is an area inside the light-shielding film 21 on the glass plate 10, and the second region A2 is an area in the upper center of the glass plate 10 covered with the light-shielding film 21, including the transmissive region At.

An information detector (on-board equipment) S is attached to the top center of the glass plate 10. This information detector S is equipped with imaging equipment such as a CCD camera or CMOS camera, or a sensor such as a laser sensor. This information detector S detects information outside the vehicle by passing through the glass plate 10. The information detector S is attached to the inside of the second area A2 of the glass plate 10, and detects information about the rear of the vehicle that passes through the transmission area At of the second area A2. In this example, the information detector S is an imaging device that captures an image of the area behind the vehicle that passes through the transmission area At. The image of the area behind the vehicle captured by the information detector S, which is made up of this imaging equipment, is then displayed on a display installed inside the vehicle and can be viewed by the driver, etc.

The vehicle glass 100 is attached at an angle to the vehicle body so that the upper side is inclined toward the front of the vehicle. For this reason, the transmission area At, which transmits the image of the rear side of the vehicle to the information detector S, gradually widens downward and is trapezoidal in shape with an upper base Ata, a lower base Atb, and a pair of inclined portions Atc, Atc.

The defogger 30 provided on the glass plate 10 is an electric heating device with a defogging function that removes fogging and frost from the glass plate 10 by passing an electric current through a heating wire to generate heat.

FIG. 3 is a schematic wiring diagram of the defogger 30.
1 and 3, the defogger 30 includes a plurality of (in this example, thirteen) heating wires 31A to 31M and a pair of bus bars 33, 33. These heating wires 31A to 31M and the bus bar 33 are conductor patterns formed by printing on the glass sheet 10, and are routed on the surface of the glass sheet 10 facing the interior of the vehicle.

The heating wires 31A to 31M extend in the vehicle width direction relative to the glass plate 10 and are arranged in a line with intervals in the vertical direction. The heating wires 31A to 31M are installed in order from the top side of the glass plate 10.

A pair of bus bars 33, 33 are positioned near both sides 15, 15 of the glass plate 10 in the vehicle width direction, extend vertically, and are positioned within the range of the light-shielding film 21. Both ends of each heating wire 31A to 31M are integrally connected to the bus bar 33.

In the defogger 30, when a voltage is applied to a pair of bus bars 33 by the power supply Ba, a current I flows through each of the heating wires 31A-31M, generating heat. This heats the glass plate 10, removing any fogging or frost from the glass plate 10. The heating wire 31M, located at the bottom, has a wavy portion 31Ma arranged in a wavy pattern on one side in the vehicle width direction (see Figure 1). This wavy portion 31Ma is located in a standby position for the wiper (not shown) attached to the wiper mounting portion 17, and the heat generated by this wavy portion 31Ma prevents the wiper from freezing to the glass plate 10.

Of the heating wires 31A-31M that make up the defogger 30, the upper multiple (two in this example) heating wires 31A, 31B are consolidated into a number fewer than the number of heating wires 31A, 31B (two in this example). In this example, the two heating wires 31A, 31B are consolidated midway to form a single heating wire 35. As a result, heating wire 31A is split on both sides in the vehicle width direction, sandwiched between heating wire 35, to form divided heating wires 31AL, 31AR. Similarly, heating wire 31B is split on both sides in the vehicle width direction, sandwiched between heating wire 35, to form divided heating wires 31BL, 31BR.

The heating wire 35 is located in the center of the vehicle width and is routed in the second area A2. Specifically, the heating wire 35 is drawn from the first area A1 to the second area A2 and routed so as to surround the transparent area At through which the information detector S acquires information.

This heating wire 35 has a pair of lower extending portions 35A, 35A, a pair of inclined extending portions 35B, 35B, and an upper extending portion 35C. The pair of lower extending portions 35A, 35A extend from the connection points 37 with the dividing heating wires 31AL, 31BL and the connection points 37 with the dividing heating wires 31AR, 31BR toward the center (downward) of the glass plate 10 in the vertical direction relative to the transparent region At, and further extend inward in the vehicle width direction and are pulled into the second region A2. The pair of inclined extending portions 35B, 35B extend upward and inward in the vehicle width direction along the inclined portion Atc of the transparent region At from the inner end of the vehicle width direction opposite the connection points 37 of the lower extending portions 35A. The upper extension portion 35C extends in the vehicle width direction so as to connect the upper ends of the pair of inclined extension portions 35B, 35B, and is a portion that fits along the upper bottom portion Ata of the transparent area At.

Furthermore, among the heating elements 31A-31M that make up the defogger 30, the heating element 31C (another heating element) that is adjacent to the center (below) of the glass plate 10 in the vertical direction relative to the transmission area At has a bulging portion 31Ca in its central portion in the vehicle width direction that bulges upward toward the second area A2. This bulging portion 31Ca is positioned along the lower bottom portion Atb of the transmission area At of the second area A2.

FIG. 4 is a circuit diagram of part B in FIG.
As shown in Figure 4, if the resistance value of the divided heating wires 31AL, 31AR, 31BL, and 31BR arranged in the first area A1 of the two upper heating wires 31A and 31B is Ra, and the resistance value of the single heating wire 35 formed by combining the two upper heating wires 31A and 31B is Rb, the combined resistance value R of the two heating wires 31A and 31B is given by equation (1).

R=Ra/2+Rb+Ra/2
=Ra+Rb...(1)

Furthermore, in the two heating wires 31A, 31B on the upper side of the combined resistance value R, when a current I flows through each of the heating wire segments 31AL, 31AR, 31BL, and 31BR, twice the current, 2I, flows through heating wire 35. As a result, if the thickness (cross-sectional area) of heating wire 35 is the same as the thickness (cross-sectional area) of heating wire segments 31AL, 31AR, 31BL, and 31BR, the heat generation amount Ws within the routing range L of heating wire 35 is given by the following equation (2).

Ws=Rb(2I) ² ...(2)

In contrast, if the two heating wires 31A, 31B are not combined, the heat generation amount Wn per heating wire in the same area as the routing range L of the heating wire 35 is expressed by the following formula (3):

Wn=( ^RbI2 )/2...(3)

In other words, the heat generation amount Ws within the routing range L of the heating wire 35 increases as the square of the current I compared to the heat generation amount Wn per wire when not bundled.

Therefore, as in this example, by consolidating the multiple heating wires 31A, 31B routed in the first area A1 and routing them to the second area A2, the amount of heat generated in the heating wire 35 routed to the second area A2 can be easily increased, preferentially heating the second area A2 and improving defogging performance to remove fogging and frost.

Here, if the length of the heating wire 35 increases by routing it in the second area A2, the resistance value Rb of the heating wire 35 increases. Therefore, in order to maintain the total power consumption Wt by setting the combined resistance value R of the two heating wires 31A, 31B to half the resistance value of each of the other heating wires 31C-31M, it is necessary to increase the thickness (cross-sectional area) of the heating wire 35, for example, to reduce the resistance value per unit length. In this way, even if the resistance value per unit length of the heating wire 35 is reduced, in this example, the current I flowing through the heating wire 35 can be doubled, significantly increasing the heat generation amount Ws in the routing range L (see Figure 4), resulting in sufficient, even, and good heating of the second area A2.

As explained above, with the vehicle glass 100 according to this embodiment, the heating wires 31A, 31B routed in the first area A1 are combined into one and routed to the second area A2, which makes it possible to easily increase the current to the heating wire 35 routed to the second area A2 and increase the amount of heat generated, thereby improving defogging performance by preferentially heating the second area A2 and removing fogging and frost.

As a result, the heat wire 35 is arranged to surround the periphery of the transmission area At from which the information detector S acquires information, and the heat from this heat wire 35 can efficiently remove fogging and frost from the transmission area At.

Furthermore, since the heating wire 35 is routed vertically and laterally in the second area A2, fogging and frost in the second area A2 can be removed evenly.

Furthermore, the information detector S is attached and positioned at the top center of the glass plate 10, and the heating wire 35, which is an aggregate of multiple heating wires 31A, 31B, has a pair of lower extensions 35A, 35A routed toward the vertical center (bottom) of the glass plate 10. In this way, by providing the heating wire 35 extending from the connection point 37 with lower extensions 35A, 35A that are routed downward on both sides of the transmission area At and then routed toward the vertical center of the glass plate 10, it is possible to efficiently heat the vertical center of the glass plate 10, where it is desired to actively remove fogging and frost in order to ensure visibility.

Furthermore, another heating wire, heating wire 31C, is drawn from the first area A1 to the second area A2 and routed near the transparent area At, so the heat from this heating wire 31C can heat the transparent area and efficiently remove frost and fogging.

In the above embodiment, the heating wires 31A-31M that make up the defogger 30 may be of the same thickness, or may have different thicknesses depending on the routing location. For example, within the desired range of active heating, the thickness of the heating wires 31A-31M may be made thinner to increase the resistance per unit length.

Furthermore, the number of heating wires concentrated in the second area A2 is not limited to two, but may be three or more.

Here, a modified example in which three heat rays are concentrated in the second area A2 will be described.
FIG. 5 is an enlarged view of part A in FIG. 1 for explaining a modified example.
5, in this modification, of the heating wires 31A to 31M that make up the defogger 30, the upper three heating wires 31A, 31B, and 31C are joined at a connection point 37 to form a single heating wire 35. As a result, the heating wire 31C is also split into split heating wires 31CL and 31CR on both sides of the heating wire 35 in the vehicle width direction.

The heating wire 35 is located in the center of the vehicle width direction, and is routed from the first area A1 to the second area A2, surrounding the periphery of the transmission area At.

In this heating wire 35, a pair of lower extensions 35A, 35A extending from the connection point 37 toward the inside in the vehicle width direction are pulled in below the lower bottom portion Atb, which is located toward the center (below) of the glass plate 10 in the vertical direction relative to the transparent region At. The lower extensions 35A are then folded back at the center of the lower bottom portion Atb of the transparent region At in the vehicle width direction and connected to the inclined extensions 35B.

In this modified example, the heating wire 35 routed around the transparent area At is configured by aggregating three heating wires 31A, 31B, and 31C. This increases the amount of heat generated by the heating wire 35, enabling more efficient removal of fogging and frost from the transparent area At. In particular, because the transparent area At is surrounded almost entirely by heating wires 35 with a high heating value, the transparent area At can be heated in a balanced manner, allowing for even removal of fogging and frost.

As such, the present invention is not limited to the above-described embodiments, and the invention also contemplates the mutual combination of the various components of the embodiments, as well as modifications and applications by those skilled in the art based on the disclosures in the specification and well-known technology, and these modifications and applications are within the scope of the protection sought.

As described above, the present specification discloses the following:
(1) A vehicle glass in which a plurality of heating wires extending in a predetermined direction are arranged side by side on a glass plate,
The glass plate is
A first region;
a second area adjacent to the first area, in which an in-vehicle device is mounted;
and
In the second region, the plurality of heating wires arranged in the first region are concentrated and routed to a number less than the number in the first region.
With this vehicle glass, by consolidating the multiple heating wires routed in the first region into a smaller number than in the first region and routing them to the second region, the current to the heating wires routed to the second region can be easily increased to increase the amount of heat generated, and the defogging performance can be improved by preferentially heating the second region to remove fogging and frost.

(2) The vehicle glass according to (1), wherein the heat rays extend in the vertical direction and the vehicle width direction in the second region.
According to this vehicle glass, the heat rays are routed in the vertical direction and the vehicle width direction in the second region, so that fogging and frost in the second region can be removed evenly.

(3) The on-board device is an information detector that detects outside information through the glass plate,
The vehicle glass according to (1) or (2), wherein in the second region, the heating wire is arranged so as to surround a periphery of a transmission region in the glass plate through which the information detector acquires information.
According to this vehicle glass, the heat of the heating wires arranged so as to surround the periphery of the transmission area through which the information detector acquires information can efficiently remove the fogging and frost from the transmission area.

(4) The information detector is disposed above the glass plate,
The vehicle glass according to (3), wherein the concentrated heat rays have a portion routed toward the center of the glass plate in the up-down direction.
With this vehicle glass, by providing a heating wire that aggregates multiple heating wires with a section that is routed and arranged toward the center of the glass plate in the vertical direction, it is possible to efficiently heat the center of the glass plate in the vertical direction, where it is desired to actively remove fogging and frost in order to ensure visibility.

(5) The vehicle glass according to (3) or (4), wherein the other heating wires routed in the first region are drawn into the second region and routed in the vicinity of the transmission region.
According to this vehicle glass, the transmission area is heated by the heat of another heating wire that is drawn from the first area to the second area and routed in the vicinity of the transmission area, thereby making it possible to efficiently remove fogging and frost.

10 Glass plate 31A to 31M Heat ray 35 Heat ray 100 Vehicle glass A1 First area A2 Second area At Transmitting area S Information detector (on-vehicle device)

Claims (5)

A vehicle glass in which a plurality of heating wires extending in a predetermined direction are arranged side by side on a glass plate,
The glass plate is
A first region;
a second area adjacent to the first area, in which an in-vehicle device is mounted;
and
In the second region, the plurality of heating wires arranged in the first region are concentrated and routed to a number smaller than the number in the first region.
Vehicle glass. In the second region, the heating wire extends in the vertical direction and the vehicle width direction.
The vehicle glass according to claim 1 . the on-board device is an information detector that detects outside-vehicle information through the glass plate,
In the second region, the heat wire is arranged so as to surround a periphery of a transmission region in the glass plate through which the information detector acquires information.
The vehicle glass according to claim 1 or 2. the information detector is disposed above the glass plate;
The concentrated heat wires have a portion that is routed toward the center of the glass plate in the up-down direction.
The vehicle glass according to claim 3. The other heating wires routed in the first region are drawn into the second region and routed in the vicinity of the transmission region.
The vehicle glass according to claim 3 or 4.