Windowpane for vehicles and method for manufacturing windowpane for vehicles

Abstract

This windowpane for vehicles comprises a glass plate for a window of a vehicle, and a defogger that is provided on the glass plate. The defogger comprises: a first bus bar that extends in the vertical direction of the glass plate; a second bus bar that extends in the vertical direction of the glass plate; a first power supply terminal that is connected to the first bus bar; a second power supply terminal that is connected to the second bus bar; a plurality of hot wires that are connected between the first bus bar and the second bus bar and extend in the horizontal direction of the glass plate; and a first conductive member which comprises a first terminal that is connected to the first power supply terminal, a second terminal that is connected to the first bus bar, and a main body part that connects the first terminal and the second terminal to each other while being at a distance from the first bus bar.

Description

Vehicle window glass and method for manufacturing the same

[0001] The present disclosure relates to vehicle window glass and a method for manufacturing the same.

[0002] Conventionally, there has been laminated glass (vehicle window glass) including a pair of glass plates facing each other, an intermediate layer positioned between the pair of glass plates and sandwiched between the pair of glass plates, and a base material positioned between the pair of glass plates and having a conductive heating element (a plurality of heating wires) on at least one main surface. The base material has, in addition to the conductive heating element (a plurality of heating wires), a first bus bar and a second bus bar connected to the conductive heating element. Further, a third bus bar is superimposed and arranged on at least a partial region of at least one of the first bus bar or the second bus bar. The first bus bar and the second bus bar are formed by an etching method such as photolithography or a printing method such as screen printing. The third bus bar is composed of a copper ribbon or a flat-woven copper wire and is directly contacted with the first bus bar or the second bus bar, or joined to the first bus bar or the second bus bar by solder or a conductive adhesive material (conductive adhesive layer) (see, for example, Japanese Unexamined Patent Application Publication No. 2019-167275).

[0003] By the way, in the conventional vehicle window glass, since the entire third bus bar is superposed and joined on the first bus bar or the second bus bar, it is not easy to design for equalizing the power density in the plurality of heating wires, and there is room for improvement in equalizing the power density in the plurality of heating wires.

[0004] In addition, since there is an upper limit temperature for the glass plate, when equalizing the power density in the plurality of heating wires, it is required to suppress the temperature rise of the bus bar with a high heating temperature due to a large current amount.

[0005] Therefore, an aspect of the present disclosure aims to provide a vehicle window glass and a method for manufacturing the same that can achieve both equalization of the power density in a plurality of heating wires and suppression of the temperature rise of the bus bar in a more advanced dimension.

[0006] The vehicle window glass of the embodiment of the present disclosure includes a glass plate for a vehicle window and a defogger provided on the glass plate, the defogger having a first bus bar extending in the vertical direction of the glass plate, a second bus bar extending in the vertical direction of the glass plate, a first power supply terminal connected to the first bus bar, a second power supply terminal connected to the second bus bar, a plurality of heating wires connected between the first bus bar and the second bus bar and extending in the left-right direction of the glass plate, a first terminal connected to the first power supply terminal, a second terminal connected to the first bus bar, and a first conductive member having a main body portion connecting the first terminal and the second terminal and spaced apart from the first bus bar.

[0007] According to this disclosure, it is possible to provide a vehicle window glass and a method for manufacturing a vehicle window glass that can achieve a higher level of compatibility between equalizing the power density in multiple heating elements and suppressing the temperature rise of the busbar.

[0008] This is a plan view showing an example of the configuration of a vehicle window glass according to the embodiment, viewed from the inside of the vehicle. This is a magnified view showing an example of the configuration around the right bypass busbar of the vehicle window glass according to the embodiment. This is a magnified view showing an example of the configuration around the right bypass busbar of the vehicle window glass according to the embodiment. This is a diagram showing an example of the state before the right power supply terminal and bypass busbar are attached to the glass plate of the vehicle window glass according to the embodiment. This is a diagram showing an example of the configuration in the cross section taken along the line A-A in Figure 3. This is a diagram schematically showing an example of the configuration in the cross section taken along the line B-B in Figure 3. This is a diagram showing an example of the current flow in the second busbar of the vehicle window glass according to the embodiment. This is a diagram showing an example of the configuration of the right bypass busbar of a modified vehicle window glass according to the embodiment.

[0009] <Embodiments> Hereinafter, embodiments for implementing this disclosure will be described with reference to the drawings. In each embodiment, deviations in directions such as parallel, perpendicular, horizontal, vertical, up and down, and left and right are permitted to the extent that they do not impair the effects of this disclosure. In addition, unless otherwise specified, the drawings showing glass plates for vehicle windows (hereinafter also referred to as "window glass") are drawings of the glass surface of the window glass viewed from the opposite side, and show the window glass installed in the vehicle from the viewpoint inside the vehicle (in-vehicle view). Furthermore, if the window glass is a windshield installed at the front of the vehicle or a rear glass installed at the rear of the vehicle, the up and down direction in the drawings showing the window glass corresponds to the up and down direction of the vehicle, and the left and right direction corresponds to the width direction of the vehicle. In addition, the window glass is not limited to a windshield or a rear glass, and may be, for example, a side glass installed on the side of the vehicle. In the diagram showing the window glass, the directions parallel to the X-axis (X-axis direction), parallel to the Y-axis (Y-axis direction), and parallel to the Z-axis (Z-axis direction) represent the left-right direction of the glass plate, the up-down direction of the glass plate, and the direction perpendicular to the surface of the glass plate, respectively. The X-axis, Y-axis, and Z-axis directions are mutually orthogonal. Also, a planar view is a view from the XY plane.

[0010] <Vehicle Window Glass 100> Figure 1 is a plan view showing an example of the configuration of a vehicle window glass 100 from the perspective of the inside of the vehicle. As an example, the vehicle window glass 100 has a symmetrical configuration with respect to a straight line (center line C) that passes through the center in the left-right direction in the vertical direction when viewed from above.

[0011] The vehicle window glass 100 shown in Figure 1 is an example of a rear window installed at the rear of a vehicle. The vehicle window glass 100 includes a glass plate 110 for the vehicle window and a defogger 120 provided on the glass plate 110. The defogger 120 has a first bus bar 130L, a second bus bar 130R, power supply terminals 135L and 135R, a plurality of heating elements 140, and bypass bus bars 150L and 150R. The bypass bus bar 150L is an example of a first conductive member, and the bypass bus bar 150R is an example of a second conductive member.

[0012] The first busbar 130L, the second busbar 130R, and the multiple heating elements 140 are formed, for example, by printing a paste containing a conductive metal (e.g., silver paste) onto the main surface 111 on the interior side of the glass plate 110 and then firing it. Methods for printing the conductive metal paste include screen printing, offset printing, gravure printing, flexographic printing, or inkjet printing. Furthermore, the first busbar 130L, the second busbar 130R, and the multiple heating elements 140 are formed from the same conductive material. The thicknesses of the first busbar 130L, the second busbar 130R, and the multiple heating elements 140 formed in this manner are approximately identical. In the following description, it will be assumed that the thicknesses of the first busbar 130L, the second busbar 130R, and the multiple heating elements 140 are identical.

[0013] The thickness of the first busbar 130L, the second busbar 130R, and the multiple heating elements 140 may be between 5 μm and 20 μm. The width (wire width) of the multiple heating elements 140 may be between 0.15 mm and 1.0 mm, or between 0.15 mm and 0.5 mm. In the following, "width of the multiple heating elements 140" refers to the wire width.

[0014] The method for forming the first busbar 130L, the second busbar 130R, and the multiple heating elements 140 is not limited to the method described above. For example, the first busbar 130L, the second busbar 130R, and the multiple heating elements 140 may be formed by providing a linear or foil-like body containing a conductive material such as copper on the main surface 111 on the interior side or the main surface on the exterior side of the glass plate 110. Alternatively, the first busbar 130L, the second busbar 130R, and the multiple heating elements 140 may be attached to the glass plate 110 with an adhesive or the like, or they may be provided inside (inner layer) the glass plate 110 itself.

[0015] Furthermore, the thicknesses of the first busbar 130L, the second busbar 130R, or the multiple heating elements 140 may be different. If the thicknesses of the first busbar 130L and the second busbar 130R are different, the resistance value per unit length should be set taking the thickness into consideration.

[0016] <Achieving a higher level of compatibility between equalizing the power density across multiple heating elements 140 and suppressing the temperature rise of the first busbar 130L and the second busbar 130R> In vehicle window glass 100, when the defogger 120 heats up multiple heating elements 140 to remove condensation, equalizing the power density across the multiple heating elements 140 is required in order to heat the glass plate 110 evenly.

[0017] The power density of the multiple heating elements 140 refers to the power density of the entire set of heating elements 140. The power density of the multiple heating elements 140 is calculated for the 17 heating elements 140 provided within the anti-fogging region 113 of the glass plate 110, per unit area (m²) of the anti-fogging region 113. ２ This is the power load (W) per unit area, and the unit is W / m ２ That is the case.

[0018] Furthermore, equalizing the power density across the multiple heating elements 140 is possible by increasing the amount of current supplied to the first busbar 130L and the second busbar 130R. However, since the glass plate 110 has an upper temperature limit, the defogger 120 is provided with an allowable upper limit on its heat generation temperature. The allowable upper limit on the heat generation temperature of the defogger 120 is, in effect, the allowable upper limit on the heat generation temperature of the first busbar 130L and the second busbar 130R, which have the highest current output within the defogger 120.

[0019] The vehicle window glass 100 achieves a higher level of balance between equalizing the power density across the multiple heating elements 140 and suppressing the temperature rise of the first busbar 130L and the second busbar 130R. In other words, the vehicle window glass 100 maintains equalization of power density without lowering the temperature of the multiple heating elements 140, while suppressing the temperature rise of the first busbar 130L and the second busbar 130R. The individual components of the vehicle window glass 100 will be described below.

[0020] <Glass Plate 110> Glass plate 110 is an example of a glass plate for a vehicle window. Glass plate 110 may be either single-pane glass or laminated glass. The following describes a configuration in which glass plate 110 is single-pane glass.

[0021] The outer shape of the glass plate 110 is approximately rectangular. The upper edge 110U represents the upper glass edge of the glass plate 110, and the lower edge 110B represents the lower glass edge of the glass plate 110 (opposite to the upper edge 110U). The left edge 110L represents the left glass edge of the glass plate 110, and the right edge 110R represents the right glass edge of the glass plate 110 (opposite to the left edge 110L). The left edge 110L is the glass edge adjacent to the left of the upper edge 110U and the lower edge 110B, and the right edge 110R is the glass edge adjacent to the right of the upper edge 110U and the lower edge 110B.

[0022] The glass plate 110 has a pair of side edges. The left edge 110L is an example of one of the pair of side edges, and the right edge 110R is an example of the other of the pair of side edges, the second side edge. The connection between the upper edge 110U and the left edge 110L is connected with curvature, but it may also be connected without curvature. The shape of the connections between other edges is similar.

[0023] The glass plate 110 has an anti-fogging region 113 and a shielding layer 115.

[0024] <Anti-fogging area 113> The anti-fogging area 113 is, for example, the area of ​​the glass plate 110 excluding a portion of the upper part. The anti-fogging area 113 of the glass plate 110 is a roughly rectangular area of ​​the glass plate 110 in which multiple heating elements 140 are provided, and it is an anti-fogging area in which fogging is removed by the heat generated by the multiple heating elements 140. The anti-fogging area 113 is shown in Figure 1, but is omitted in other figures.

[0025] The anti-fogging region 113 is a roughly rectangular region that extends vertically from the lower edge 110B of the glass plate 110 to just before the upper edge 110U, and horizontally between the left edge 110L and the right edge 110R. For example, the upper end of the anti-fogging region 113 is located about 1 / 5 of the vertical length of the glass plate 110, just before the upper edge 110U.

[0026] The outer edge of the anti-fogging region 113 is located outside the opening 115A of the shielding layer 115 on the lower edge 110B side, outside the opening 115A of the shielding layer 115 on the left edge 110L side and the right edge 110R side, and inside the opening 115A of the shielding layer 115 on the upper edge 110U side.

[0027] Within the anti-fogging area 113, for example, 17 heating elements 140 extend in the left-right direction. In the following, when describing which of the 17 heating elements 140 is the first from the top, it may simply be referred to as the "nth" element. Also, in the diagram, the number (No.) of each heating element 140 will be distinguished.

[0028] A camera for acquiring images of the outside of the vehicle, or a lamp such as a high-mounted stop lamp, may be provided on the interior side of the vehicle window glass 100, but these are omitted here. Furthermore, a through-hole for the wiper pivot (the rotation axis of the wiper) of the wiper may be provided in the vehicle window glass 100, but this is also omitted here.

[0029] If a camera or lamp is installed, the camera or lamp should be positioned within the anti-fogging area 113. This is to ensure a clear view within the camera's imaging range, or to improve the visibility of the lit lamp from outside the glass plate 110. If a wiper is installed, the wiper's wiping area should be positioned within the anti-fogging area 113. In these cases, the position of the heating element 140 can be appropriately changed to match the position of the camera or lamp, or the wiper's wiping area, thereby appropriately changing the position of the anti-fogging area 113.

[0030] <Shielding layer 115> The shielding layer 115 is a frame-shaped layer provided along the outer edge (upper edge 110U, left edge 110L, lower edge 110B, and right edge 110R) of the glass plate 110. The shielding layer 115 has an opening 115A that exposes almost the entire area inside the outer edge of the glass plate 110. The shielding layer 115 may also be provided with protrusions and openings that project inward from the opening edge of the opening 115A to shield the area around the camera or lamp, and openings to avoid through holes for the wiper pivot (rotation axis of the wiper) of the wiper.

[0031] Specific examples of the shielding layer 115 include ceramics such as a black ceramic layer. The shielding layer 115 is formed by printing a ceramic paste containing black pigment and glass frit onto the main surface 111 on the interior side of the glass plate 110 and firing it. As a printing method for the ceramic paste containing black pigment and glass frit, screen printing, offset printing, gravure printing, flexographic printing, or inkjet printing can be used. When the glass plate 110 is viewed from the outside of the vehicle, the part that overlaps with the shielding layer 115 is not visible from the outside, resulting in a glass plate 110 with an excellent design.

[0032] <Defogger 120> The defogger 120 is an electrically heated conductive pattern that removes condensation from the glass plate 110. Here, in addition to Figure 1, Figures 2 to 6 will be used for explanation. Figures 2 and 3 are enlarged views showing an example of the configuration around the bypass bus bar 150R of the vehicle window glass 100. Figure 4 is a view showing an example of the state before the power supply terminal 135R and the bypass bus bar 150R are attached to the glass plate 110. In Figure 4, the positions where the power supply terminal 135R and the bypass bus bar 150R are provided on the surface of the second bus bar 130R are indicated by dashed lines. Figure 5 is a view showing an example of the configuration of the cross section taken along the line A-A in Figure 3. In Figure 5, the glass plate 110, the shielding layer 115, and the second bus bar 130R are shown in cross section, and the bypass bus bar 150R is shown in side view. Furthermore, in order to show the position of the main surface 111 on the interior side of the glass plate 110, the glass plate 110 is shown to be longer than the shielding layer 115 and the second bus bar 130R. Figure 6 is a diagram showing an example of the configuration of the cross section taken along the line B-B in Figure 3. Figure 6 schematically shows an example of the cross-sectional structure including the terminal 135A1 of the power supply terminal 135R.

[0033] The defogger 120 includes a plurality of heating elements 140 extending in the left-right direction of the glass plate 110, a first busbar 130L and a second busbar 130R that supply power to the plurality of heating elements 140, power supply terminals 135L and 135R, and bypass busbars 150L and 150R. The first busbar 130L and the second busbar 130R form a pair. The bypass busbars 150L and 150R also form a pair.

[0034] In this embodiment, 17 heating wires 140 extending in the left-right direction of the glass plate 110 so as to run parallel to each other, a first bus bar 130L and a second bus bar 130R connected to the 17 heating wires 140, power supply terminals 135L and 135R, and bypass bus bars 150L and 150R are provided on the interior side of the glass plate 110.

[0035] The first busbar 130L is connected to the power supply terminal 135L, and the second busbar 130R is connected to the power supply terminal 135R. When a voltage is applied between the first busbar 130L and the second busbar 130R from the power supply terminals 135L and 135R, the 17 heating wires 140 are energized and generate heat, removing the condensation from the glass plate 110.

[0036] <First busbar 130L and second busbar 130R> The first busbar 130L and the second busbar 130R are conductor patterns that extend vertically along the left edge 110L and the right edge 110R of the glass plate 110, respectively. As an example, the first to seventeenth heating wires 140 are connected between the first busbar 130L and the second busbar 130R. The first busbar 130L and the second busbar 130R are located outside the opening 115A of the shielding layer 115 and overlap with the shielding layer 115.

[0037] The first busbar 130L has an upper end 131L and a lower end 132L, and extends vertically between the upper end 131L and the lower end 132L. The second busbar 130R has an upper end 131R and a lower end 132R, and extends vertically between the upper end 131R and the lower end 132R.

[0038] The first busbar 130L and the second busbar 130R, for example, have a shape that is symmetrical with respect to the center line C as the axis of symmetry. The first busbar 130L and the second busbar 130R are connected to power supply terminals 135L and 135R, respectively, at a position slightly above the center in the vertical direction. DC power is supplied to the first busbar 130L and the second busbar 130R from a DC power supply of the vehicle (not shown) via the power supply terminals 135L and 135R.

[0039] <Power supply terminals 135L, 135R> Power supply terminals 135L and 135R are metal members provided along the left edge 110L and right edge 110R of the glass plate 110, respectively. Power supply terminals 135L and 135R are manufactured, for example, by bending sheet metal. Examples of sheet metal materials include copper, copper alloy, aluminum, aluminum alloy, stainless steel, etc. Copper is oxygen-free copper with tin plating on the surface. Alternatively, power supply terminals 135L and 135R may be cast, for example. Examples of metal materials used in casting include copper (oxygen-free copper + tin plating), copper alloy, aluminum, aluminum alloy, etc. Here, as an example, a form in which power supply terminals 135L and 135R are manufactured from sheet metal will be described.

[0040] The power supply terminals 135L and 135R have, for example, identical configurations. Power supply terminal 135L is attached to the surface of the first busbar 130L on the +Z side, and power supply terminal 135R is attached to the surface of the second busbar 130R on the +Z side. Here, the configuration of power supply terminal 135R, shown in enlarged view in Figures 3 to 5, will be described. In the following, each component of power supply terminal 135R, shown in enlarged view in Figures 3 to 5, may be described as also existing for power supply terminal 135L.

[0041] The power supply terminal 135R has a base portion 135A and a terminal 135B. The power supply terminal 135R is manufactured, for example, by bending sheet metal. More specifically, as shown in Figure 5 as an example, a roughly C-shaped shape extending from terminal 135A2 of the base portion 135A to the tip of terminal 135B and an L-shaped shape extending from terminal 135A1 of the base portion 135A to the base of terminal 135B are manufactured from a single sheet of metal. The roughly C-shaped shape extending from terminal 135A2 of the base portion 135A to the tip of terminal 135B and the L-shaped shape extending from terminal 135A1 of the base portion 135A to the base of terminal 135B may each be manufactured from separate sheet metals. In this case, the two sheet metals constituting the power supply terminal 135R may be mechanically joined by welding or screwing.

[0042] The base portion 135A is a plate-like portion attached to the surface of the second bus bar 130R, and terminals 135A1 and 135A2 are provided at both ends. In a state where the power supply terminal 135R is attached to the surface of the second bus bar 130R, the terminal 135A1 is located at the end on the +Y direction side of the base portion 135A, and the terminal 135A2 is located at the end on the -Y direction side of the base portion 135A. The terminals 135A1 and 135A2 are located at the tips of leg portions bent in the -Z direction side (the surface side of the second bus bar 130R) with respect to the base portion 135A.

[0043] The terminals 135A1 and 135A2 are configured substantially parallel to the XY plane so as to fit on the surface of the second bus bar 130R. The power supply terminal 135R is attached to the surface on the +Z direction side of the second bus bar 130R by joining the terminals 135A1 and 135A2 of the base portion 135A to the surface of the second bus bar 130R with solder or a conductive adhesive. As an example, as shown in FIG. 6, the terminal 135A1 is connected to the surface on the +Z direction side of the second bus bar 130R by solder 137.

[0044] As an example, the solder can be solder containing Sn (tin) and Pb (lead), or lead-free solder containing Sn and Ag (silver). The conductive adhesive is formed, for example, by printing a paste containing a conductive metal (such as silver paste, etc.) on the terminals 135A1 and 135A2 and baking it.

[0045] The terminal 135B stands up from between the terminals 135A1 and 135A2 of the base portion 135A in the +Z direction, and the tip is bent, for example, toward the -Y direction. A connector at the tip of a power cable connected to a DC power supply (not shown) of the vehicle is connected to the terminal 135B.

[0046] As an example, the terminal 135B of the power supply terminal 135R is connected to one terminal (for example, the positive polarity terminal) of the DC power supply of the vehicle, and the terminal 135B of the power supply terminal 135L is connected to the other terminal (for example, the negative polarity terminal) of the DC power supply of the vehicle.

[0047] DC current is supplied to the power supply terminals 135L and 135R from a DC power supply (not shown) of the vehicle. This DC current is supplied from the power supply terminals 135L and 135R to the 17 heating elements 140 via the first busbar 130L and the second busbar 130R. At this time, a portion of the DC current flows from the power supply terminals 135L and 135R through the bypass busbars 150L and 150R to the first busbar 130L and the second busbar 130R, and is supplied to some of the 17 heating elements 140. Details of this will be described later.

[0048] Since terminals 135A1 and 135A2 of the base 135A are connected to the second busbar 130R, the DC current supplied from the vehicle's DC power supply is supplied to the second busbar 130R via terminals 135A1 and 135A2. Therefore, the part of the second busbar 130R where terminals 135A1 and 135A2 are connected becomes the power supply point.

[0049] The power supply terminals 135L and 135R are attached to the surfaces of the first busbar 130L and the second busbar 130R on the +Z side, at a position slightly above the center of the first busbar 130L and the second busbar 130R in the vertical direction. The positions of the power supply terminals 135L and 135R in the vertical direction of the glass plate 110 are determined by the structure of the vehicle, etc. Here, as an example, a configuration in which the power supply terminals 135L and 135R are provided at the positions shown in Figure 1 will be described.

[0050] Furthermore, although this description focuses on a configuration in which the base 135A of the power supply terminal 135R has two terminals 135A1 and 135A2, the base 135A may have only one terminal (for example, one of terminals 135A1 and 135A2). Alternatively, the base 135A of the power supply terminal 135R may have three or more terminals, and these three or more terminals may be joined to the surface of the second busbar 130R on the +Z direction side.

[0051] Next, before explaining the heating element 140, we will explain the bypass busbars 150L and 150R.

[0052] <Bypass bus bars 150L, ​​150R> Bypass bus bars 150L and 150R are metal members provided on the -Y direction side (lower side) of the power supply terminals 135L and 135R, and on the +Z direction surface of the first bus bar 130L and the second bus bar 130R, respectively. Bypass bus bars 150L and 150R extend along the left edge 110L and the right edge 110R of the glass plate 110.

[0053] Bypass busbars 150L and 150R are manufactured, for example, by bending sheet metal. Examples of sheet metal materials include copper, copper alloys, aluminum, aluminum alloys, and stainless steel. The copper used is oxygen-free copper with a tin plating. Alternatively, bypass busbars 150L and 150R may be manufactured as castings. Examples of metal materials used in casting include copper (oxygen-free copper + tin plating), copper alloys, aluminum, and aluminum alloys. Here, we will describe an example of a bypass busbar 150L and 150R manufactured from sheet metal.

[0054] Bypass busbars 150L and 150R have, for example, identical configurations. Here, the configuration of bypass busbar 150R, shown in enlarged view in Figures 3 to 5, will be described. In the following, each component of bypass busbar 150R, shown in enlarged view in Figures 3 to 5, may be described as also existing for bypass busbar 150L.

[0055] The bypass busbar 150R has a main body 151 and terminals 152A and 152B. In the bypass busbar 150R, which is an example of a second conductive member, the main body 151 is an example of a second main body, terminal 152A is an example of a third terminal, and terminal 152B is an example of a fourth terminal. In the bypass busbar 150L (an example of a first conductive member) which has the same configuration as the bypass busbar 150R, the main body 151 is an example of a first main body, terminal 152A is an example of a first terminal, and terminal 152B is an example of a second terminal.

[0056] The main body portion 151 is an elongated plate-shaped part that connects terminals 152A and 152B. The length between terminals 152A and 152B of a bypass busbar 150R having such a main body portion 151 is, for example, 15 mm or more and 200 mm or less. For ease of installation, 150 mm or less is more preferable, and 100 mm or less is even more preferable.

[0057] Terminal 152A is located at the +Y direction end of the main body 151. For example, there is no step between terminal 152A and the main body 151, and terminal 152A is located on the extension of the main body 151. Terminal 152A of the bypass busbar 150R is connected to terminal 135A2 of the power supply terminal 135R by solder or conductive adhesive, with the terminal 152A overlapping the terminal 135A2 on the +Z direction side of terminal 135A2. For example, solder containing Sn (tin) and Pb (lead), or lead-free solder containing Sn and Ag (silver) can be used. For example, conductive adhesive is formed by printing a paste containing a conductive metal (e.g., silver paste) onto terminal 152A and baking it.

[0058] Furthermore, terminal 152A of the bypass busbar 150R and terminal 135A2 of the power supply terminal 135R may be joined by a mechanically connected joint. The mechanical joint is, for example, a joining structure that utilizes crimping, fitting, or screw fastening. In this case, the joining structure that joins terminal 152A and terminal 135A2 by crimping, fitting, or screw fastening may be present on terminal 152A, on terminal 135A2, or on both terminal 152A and terminal 135A2.

[0059] Terminal 152B is located at the -Y direction end of the main body 151. As an example, a bent portion 153 is provided between terminal 152B and the main body 151. Terminal 152B of the bypass busbar 150R is connected to the connection point 133R of the second busbar 130R by solder or conductive adhesive. The same solder or conductive adhesive used to connect terminal 152A to terminal 135A2 of the power supply terminal 135R may be used.

[0060] The bent portion 153 is provided to absorb the height difference between the terminal 135A2 to which the terminal 152A is connected and the surface of the second busbar 130R on the +Z direction, thereby keeping the distance between the main body 151 and the second busbar 130R in the Z direction constant in the Y direction. The bent portion 153 is a portion bent toward the second busbar 130R at the -Y direction end of the main body 151. The tip of the bent portion 153 is parallel to the XY plane. With the bent portion 153 provided, there is a step between the portion of the tip of the bent portion 153 that is parallel to the XY plane and the main body 151. Note that the distance between the main body 151 and the second busbar 130R in the Z direction does not have to be constant in the Y direction. In this case, the bypass busbar 150R does not have to have the bent portion 153.

[0061] The bypass busbar 150R, having the configuration described above, connects terminal 135A2 of the power supply terminal 135R to connection point 133R (see Figure 1) of the second busbar 130R. The bypass busbar 150R is spaced apart from the second busbar 130R in the +Z direction between terminal 135A2 of the power supply terminal 135R and connection point 133R (see Figure 1) of the second busbar 130R, and is not connected to any other conductive members. Therefore, the bypass busbar 150R transmits DC current between terminal 135A2 of the power supply terminal 135R and connection point 133R (see Figure 1) of the second busbar 130R.

[0062] Similarly, the bypass busbar 150L connects terminal 135A2 of the power supply terminal 135L to connection point 133L of the first busbar 130L (see Figure 1). The bypass busbar 150L is spaced apart from the first busbar 130L in the +Z direction between terminal 135A2 of the power supply terminal 135L and connection point 133L of the first busbar 130L (see Figure 1), and is not connected to any other conductive members. Therefore, the bypass busbar 150L transmits DC current between terminal 135A2 of the power supply terminal 135L and connection point 133L of the first busbar 130L (see Figure 1).

[0063] In the thickness direction (Z direction) of the first bus bar 130L, the distance at which the bypass bus bar 150L separates from the first bus bar 130L is preferably 0.5 mm or more and 3.0 mm or less, and more preferably 1.0 mm or more and 2.0 mm or less. The same applies to the distance at which the bypass bus bar 150R separates from the second bus bar 130R.

[0064] Furthermore, the thickness of the bypass busbars 150L and 150R is preferably, for example, 0.5 mm or more and 1.1 mm or less, and more preferably 0.7 mm or more and 1.0 mm or less.

[0065] The bypass busbars 150L and 150R are made of sheet metal and possess sufficient strength, so they maintain their position separated in the Z direction from the first busbar 130L and second busbar 130R without deformation. This is also true when the bypass busbars 150L and 150R are made of cast metal.

[0066] The thickness of the bypass busbars 150L and 150R is at least 25 times thicker than the thickness of the first busbar 130L and second busbar 130R (5 μm to 20 μm), and the width in the X direction is, for example, about half. Furthermore, because the bypass busbars 150L and 150R are made of sheet metal, their resistivity per unit length is lower than that of the first busbar 130L and second busbar 130R, which are made of silver paste or the like.

[0067] For these reasons, the resistance between terminals 152A and 152B of the bypass busbar 150L is significantly lower than the resistance between the portion of the first busbar 130L to which terminal 135A2 of the power supply terminal 135L is connected and the connection point 133L. Similarly, the resistance between terminals 152A and 152B of the bypass busbar 150R is significantly lower than the resistance between the portion of the second busbar 130R to which terminal 135A2 of the power supply terminal 135R is connected and the connection point 133R.

[0068] Therefore, when the positive polarity terminal of the vehicle's DC power supply is connected to terminal 135B of the power supply terminal 135R, current flows from terminal 135A2 of the power supply terminal 135R to the connection point 133R via the bypass bus bar 150R. Since the resistance of the bypass bus bar 150R is very small, the potential difference between terminal 135A2 and the connection point 133R becomes negligibly small.

[0069] Furthermore, when the negative terminal of the vehicle's DC power supply is connected to terminal 135B of the power supply terminal 135L, current will flow from the connection point 133R to terminal 135A2 via the bypass bus bar 150L between terminal 135A2 of the power supply terminal 135L and the connection point 133L of the first bus bar 130L. Since the resistance of the bypass bus bar 150L is very small, the potential difference between the connection point 133L and terminal 135A2 becomes negligibly small.

[0070] Because this current flow is obtained, in the second bus bar 130R, the three points where terminals 135A1 and 135A2 of the power supply terminal 135R and terminal 152B of the bypass bus bar 150R are connected become power supply points. Similarly, in the first bus bar 130L, the three points where terminals 135A1 and 135A2 of the power supply terminal 135L and terminal 152B of the bypass bus bar 150L are connected become power supply points.

[0071] Thus, the first busbar 130L and the second busbar 130R each have three feed points in the vertical direction. In the following, when distinguishing between the three feed points, they will be referred to as the first feed point, the second feed point, and the third feed point, from top to bottom.

[0072] For the first busbar 130L, the first power supply point is the point to which terminal 135A1 of power supply terminal 135L is connected. The second power supply point is the point to which terminal 135A2 of power supply terminal 135L is connected. The third power supply point is the point to which terminal 152B of bypass busbar 150L is connected.

[0073] Similarly, for the second busbar 130R, the first power supply point is the point to which terminal 135A1 of power supply terminal 135R is connected. The second power supply point is the point to which terminal 135A2 of power supply terminal 135R is connected. The third power supply point is the point to which terminal 152B of bypass busbar 150R is connected.

[0074] In the following, when describing the first, second, and third power supply points, terminals 135A1, 135A2, and 152B may be indicated in parentheses.

[0075] The current flow between terminal 135A2 and connection point 133R, and the current flow between connection point 133L and terminal 135A2 will be described later using Figure 7. Before that, the heating element 140 will be explained.

[0076] <Heating Wires 140> In explaining the configuration of the 17 heating wires 140 and the flow of current, Figure 7 will be used in addition to Figures 1 to 6. Figure 7 is a diagram showing an example of the flow of current in the second busbar 130R of the vehicle window glass 100.

[0077] The 17 heating wires 140 are a conductor pattern connected between the first busbar 130L and the second busbar 130R. Here, as an example, we will explain assuming that the current flows from the second busbar 130R on the right to the first busbar 130L on the left. Also, the width of the heating wires 140 refers to the line width.

[0078] Each of the 17 heating elements 140 has a left end connected to the left first busbar 130L and a right end connected to the right second busbar 130R. The left end of each heating element 140 is the connection point between the left first busbar 130L and the heating element 140, and the right end of each heating element 140 is the connection point between the right second busbar 130R and the heating element 140. The left and right ends of the 17 heating elements 140 overlap with the shielding layer 115.

[0079] Each of the 17 heating elements 140 is required to be relatively narrow in width so as not to obstruct the view. The width of each heating element 140 is preferably 1 mm or less, and 1 mm or less is one standard for the width of the heating elements 140.

[0080] <The first to seventh heating elements 140> Of the 17 heating elements 140, the upper seven (the first to seventh) are connected to the upper part of the first busbar 130L and the second busbar 130R above the first power supply point (terminal 135A1). Therefore, current is supplied from the first power supply point (terminal 135A1) of the first busbar 130L and the second busbar 130R. More specifically, the first to seventh heating elements 140 are supplied with current from the first power supply point (terminal 135A1) of the second busbar 130R, and the current that passes through the first to seventh heating elements 140 flows towards the first power supply point (terminal 135A1) of the first busbar 130L.

[0081] <The 8th heating element 140> Of the 17 heating elements 140, the 8th heating element 140 from the top is the heating element 140 closest to the second power supply point (terminal 135A2) of the first busbar 130L and the second busbar 130R. Therefore, current is supplied to the 8th heating element 140 from the second power supply point (terminal 135A2) of the first busbar 130L and the second busbar 130R. More specifically, current is supplied to the 8th heating element 140 from the second power supply point (terminal 135A2) of the second busbar 130R, and the current that passes through the 8th heating element 140 flows toward the second power supply point (terminal 135A2) of the first busbar 130L.

[0082] <The 9th and 10th heating elements 140> Of the 17 heating elements 140, the 9th and 10th heating elements 140 from the top are connected to the portion between the second power supply point (terminal 135A2) and the third power supply point (terminal 152B) of the first busbar 130L and the second busbar 130R. Therefore, as shown in Figure 7, current is supplied to the 9th and 10th heating elements 140 from the second power supply point (terminal 135A2) and the third power supply point (terminal 152B) of the second busbar 130R, as indicated by the arrows.

[0083] More specifically, the ninth heating element 140 is supplied with current from the second power supply point (terminal 135A2) of the second busbar 130R, as indicated by the downward arrow, and the current that passes through the ninth heating element 140 flows upward toward the second power supply point (terminal 135A2) of the first busbar 130L.

[0084] Furthermore, the tenth heating element 140 is supplied with current from the third power supply point (terminal 152B) of the second busbar 130R, as indicated by the upward-pointing arrow, and the current that passes through the tenth heating element 140 flows downward toward the third power supply point (terminal 152B) of the first busbar 130L.

[0085] Strictly speaking, there may be cases where the ninth heating element 140 has a current component supplied from the third power supply point (terminal 152B) of the first busbar 130L and the second busbar 130R. Also, there may be cases where the tenth heating element 140 has a current component supplied from the second power supply point (terminal 135A2) of the first busbar 130L and the second busbar 130R. However, these are very small and can be ignored, so here we will explain assuming that the ninth heating element 140 is supplied with current from the second power supply point (terminal 135A2) and the tenth heating element 140 is supplied with current from the third power supply point (terminal 152B).

[0086] The reason why current flows between the first busbar 130L and the second busbar 130R to the ninth and tenth heating elements 140 in this manner is that there is almost no potential difference between the second power supply point (terminal 135A2) and the third power supply point (152B) at each of the first busbar 130L and the second busbar 130R. This is because the second power supply point (terminal 135A2) and the third power supply point (152B) are connected by bypass busbars 150L and 150R, which have very low resistance values.

[0087] <The 11th heating element 140> Of the 17 heating elements 140, the 11th heating element 140 from the top is the heating element 140 closest to the third power supply point (terminal 152B) of the first bus bar 130L and the second bus bar 130R. Therefore, current is supplied to the 11th heating element 140 from the third power supply point (terminal 152B) of the first bus bar 130L and the second bus bar 130R. More specifically, current is supplied to the 11th heating element 140 from the third power supply point (terminal 152B) of the second bus bar 130R, and the current that passes through the 11th heating element 140 flows toward the third power supply point (terminal 152B) of the first bus bar 130L.

[0088] <The 12th to 17th heating elements 140> The lower six heating elements 140 (the 12th to 17th) of the 17 heating elements 140 are connected to the lower part of the first busbar 130L and the second busbar 130R below the third power supply point (terminal 152B), and therefore current is supplied from the third power supply point (terminal 152B) of the first busbar 130L and the second busbar 130R. More specifically, current is supplied to the 12th to 17th heating elements 140 from the third power supply point (terminal 152B) of the second busbar 130R, and the current that passes through the 12th to 17th heating elements 140 flows toward the third power supply point (terminal 152B) of the first busbar 130L.

[0089] <Equalization of power density and suppression of temperature rise in the first busbar 130L and second busbar 130R> Current flows between the first busbar 130L and the second busbar 130R in the first to seventeenth heating elements 140, as described above.

[0090] Here, we consider the current flow in a comparative vehicle window glass in which the defogger 120 does not have bypass busbars 150L and 150R. In the comparative vehicle window glass, the first busbar 130L and the second busbar 130R have a first power supply point (terminal 135A1) and a second power supply point (terminal 135A2), but there is no third power supply point (terminal 152B). In this case, current flows through the first to seventh heating elements 140 as described above, but current is supplied to the eighth to seventeenth heating elements 140 from the second power supply point (terminal 135A2).

[0091] The eighth heating element 140 receives current almost directly from the second power supply point (terminal 135A2), but the ninth to seventeenth heating elements 140 are located below the second power supply point (terminal 135A2), and therefore receive current via the portion of the second busbar 130R that is below the second power supply point (terminal 135A2).

[0092] Designing the first busbar 130L, the second busbar 130R, and the 17 heating elements 140 to equalize the power density across the 17 heating elements 140, with more than half (9) of the heating elements 140 connected below the second power supply point (terminal 135A2), is not easy due to the large number of factors that must be considered.

[0093] Furthermore, because more than half (9) of the heating wires 140 are connected below the second power supply point (terminal 135A2), current concentrates in the portion of the second busbar 130R below the second power supply point (terminal 135A2), causing the temperature of the second busbar 130R to rise. The second power supply point (terminal 135A2) has the most heating wires 140 connected to it among the vehicle window glass used for comparison, so the temperature of the second busbar 130R rises the most at this point. The same is true for the first busbar 130L.

[0094] In contrast, in the vehicle window glass 100, the defogger 120 has bypass busbars 150L and 150R, which adds a third power supply point (terminal 152B) to the first busbar 130L and the second busbar 130R. The third power supply point (terminal 152B) is at approximately the same potential as the second power supply point (terminal 135A2).

[0095] Therefore, of the ninth and tenth heating elements 140 connected to the first busbar 130L and the second busbar 130R between the second power supply point (terminal 135A2) and the third power supply point (terminal 152B), a current can be supplied to the tenth heating element 140, which is closer to the third power supply point (terminal 152B), moving upward from the third power supply point (terminal 152B). Such a current flow does not occur in the comparative vehicle window glass.

[0096] Furthermore, the eleventh heating element 140 receives current almost directly from the third power supply point (terminal 152B). This is similar to how the eighth heating element 140 in the comparative vehicle window glass receives current almost directly from the second power supply point (terminal 135A2).

[0097] Furthermore, the presence of bypass busbars 150L and 150R allows the lowest power supply points of the first busbar 130L and the second busbar 130R to be positioned lower compared to the window glass used for comparison with a vehicle.

[0098] Therefore, the number of heating elements 140 that receive current downward from the lowest power supply points of the first busbar 130L and the second busbar 130R can be reduced. In the comparative vehicle window glass, current is supplied downward from the second power supply point (terminal 135A2) to nine heating elements 140 (from the 9th to the 17th), but in the vehicle window glass 100, the heating elements 140 that receive current downward from the third power supply point (terminal 152B) are six heating elements 140, from the 12th to the 17th.

[0099] Thus, there are six heating elements 140 that supply current downward from the third power supply point (terminal 152B), which is about one-third of all heating elements 140. This is a significant reduction compared to a vehicle window glass used for comparison, where more than half (nine) of the heating elements 140 are connected below the second power supply point (terminal 135A2), which is the lowest power supply point. As a result, the temperature rise of the first busbar 130L and the second busbar 130R can be suppressed.

[0100] Furthermore, by positioning the lowest power supply points of the first busbar 130L and the second busbar 130R further down, the lowest power supply points of the first busbar 130L and the second busbar 130R can be brought closer to the lowest 17th heating element 140, making it easier to supply current to the 17th heating element 140, which is furthest from the power supply point.

[0101] For the reasons stated above, the vehicle window glass 100 can significantly reduce the number of factors that need to be considered during the design phase to equalize the power density of the 17 heating elements 140 compared to a comparative vehicle window glass. Therefore, power density equalization can be easily achieved with the vehicle window glass 100. In addition, by providing bypass busbars 150L and 150R in the vehicle window glass 100, the number of heating elements 140 that receive current downward from the third power supply point (terminal 152B) can be reduced, thereby suppressing the temperature rise of the first busbar 130L and the second busbar 130R.

[0102] Therefore, it is possible to achieve both equalization of power density in the multiple heating elements 140 and suppression of temperature rise in the first busbar 130L and the second busbar 130R at a more advanced level.

[0103] In this description, we have explained a configuration in which the ninth and tenth heating elements 140 are connected to the portion between the second power supply point (terminal 135A2) and the third power supply point (terminal 152B) of the first busbar 130L and the second busbar 130R. In this configuration, as shown in Figure 7, a downward current flows from the second power supply point (terminal 135A2) towards the ninth heating element 140 in the second busbar 130R, and an upward current flows from the third power supply point (terminal 152B) towards the tenth heating element 140. This reduces the amount of current in the second busbar 130R below the third power supply point (terminal 152B).

[0104] The heating element 140 connected to the portion of the first busbar 130L and the second busbar 130R between the second power supply point (terminal 135A2) and the third power supply point (terminal 152B) may be three or more. This is because, as with the case of two heating elements, the current flow through the second busbar 130R can be reduced below the third power supply point (terminal 152B).

[0105] Therefore, if N is the number of heating wires 140 connected to the portion between the second power supply point (terminal 135A2) and the third power supply point (terminal 152B) of the first busbar 130L and the second busbar 130R, then N can be an integer of 2 or more.

[0106] In Figure 7, in order to increase the number N of heating elements 140, the position of the third power supply point (terminal 152B) should be shifted downwards (towards the -Y direction). More specifically, the position of terminal 152B of the bypass busbars 150L and 150R should be shifted below the position of the twelfth heating element 140.

[0107] The number N of heating wires 140 connected to the portion of the first busbar 130L and the second busbar 130R between the second power supply point (terminal 135A2) and the third power supply point (terminal 152B) should be determined by considering the balance between the amount of current between the second power supply point (terminal 135A2) and the third power supply point (terminal 152B) of the second busbar 130R and the amount of current below the third power supply point (terminal 152B), etc.

[0108] <Calculation results in the simulation> The maximum temperature of the second busbar 130R was calculated in a simulation for vehicle window glass 100 and a comparison vehicle window glass, and the following results were obtained.

[0109] In the vehicle window glass 100 and a comparison vehicle window glass, a voltage of 12V was applied to terminal 135B of the power supply terminal 135R, the temperature of the glass plate 110 before heating by the defogger 120 was 23°C, the length of the heating element 140 was 1100mm to 1200mm, and the power density was 375W / m ２ ~450W / m ２ Assuming it was within that range, the maximum temperature of the second busbar 130R was calculated.

[0110] In the comparative vehicle window glass, calculations were performed for the 9th to 17th heating elements 140. The maximum temperature of the second busbar 130R was 91°C at the second power supply point (terminal 135A2), and the current value was 11.8 [A]. The 9th to 17th heating elements 140 are the heating elements 140 connected below the lowest power supply point (second power supply point) of the second busbar 130R in the comparative vehicle window glass. If the upper limit temperature of the glass plate 110 is 70°C, then in the comparative vehicle window glass, the upper limit temperature of the glass plate 110 may be exceeded near the second power supply point.

[0111] In contrast, when calculations were performed for the 12th to 17th heating elements 140 of the vehicle window glass 100, the maximum temperature of the second busbar 130R was 60°C at the third power supply point (terminal 152B), and the current value was 7.94 [A]. The 12th to 17th heating elements 140 are heating elements 140 that are connected to the vehicle window glass 100 below the power supply point (third power supply point) located at the lowest part of the second busbar 130R. Assuming that the upper limit temperature of the glass plate 110 is 70°C, it is considered that the vehicle window glass 100 will not exceed the upper limit temperature of the glass plate 110.

[0112] From the above calculation results, it was confirmed that the vehicle window glass 100 can significantly reduce the maximum temperature of the second busbar 130R while achieving the same level of power density equalization as the comparative vehicle window glass.

[0113] <Method for manufacturing vehicle window glass 100> The method for manufacturing vehicle window glass 100 includes, as an example, a glass plate 110 for a vehicle window and a defogger 120 provided on the glass plate 110.

[0114] When assembling the defogger 120 to the glass plate 110, a first busbar 130L and a second busbar 130R extending in the vertical direction of the glass plate 110, and a plurality of heating wires 140 connected between the first busbar 130L and the second busbar 130R and extending in the left-right direction of the glass plate 110 are formed by printing or etching.

[0115] Next, power supply terminals 135L and 135R are connected to the first busbar 130L and the second busbar 130R, respectively. Furthermore, with the main body 151 of the bypass busbar 150L, ​​which includes a first terminal 152A, a second terminal 152B, and a main body 151 connecting the first terminal 152A and the second terminal 152B, separated from the first busbar 130L, the first terminal 152A and the second terminal 152B are connected to the power supply terminals 135L and the first busbar 130L, respectively. With these steps completed, the vehicle window glass 100 is finished.

[0116] In the above description, the power supply terminals 135L and 135R are located above the vertical center of the first busbar 130L and the second busbar 130R, and therefore, a configuration in which bypass busbars 150L and 150R are provided below the power supply terminals 135L and 135R has been described. However, if the power supply terminals 135L and 135R are located below the vertical center of the first busbar 130L and the second busbar 130R, then bypass busbars 150L and 150R should be provided above the power supply terminals 135L and 135R.

[0117] Furthermore, the above describes a configuration in which the bypass busbars 150L and 150R are connected to the first busbar 130L and the second busbar 130R, respectively. However, as an example, if the glass plate 110 is asymmetrical on the left and right sides, and the vertical length on one side is longer than the vertical length on the other side, a bypass busbar may be provided only on the side with the longer vertical length.

[0118] Furthermore, the above description has focused on a configuration in which the first busbar 130L and the second busbar 130R are arranged on the left and right sides of the glass plate 110, respectively, and the multiple heating elements 140 extend in the left-right direction of the glass plate 110. However, as an example, the first busbar and the second busbar may be provided on either the left or right side of the glass plate 110, on the upper and lower sides, respectively. In this case, the multiple heating elements 140 extend in a U-shape between the first busbar and the second busbar, connecting them. In this case, the two bypass busbars can be provided on the first busbar and the second busbar, similar to the bypass busbars 150L and 150R for the first busbar 130L and the second busbar 130R.

[0119] <Modification> Figure 8 shows an example of the configuration of a bypass bus bar 150M of a vehicle window glass 100M of a modification of the embodiment. The vehicle window glass 100M includes a defogger 120M instead of the defogger 120 of the vehicle window glass 100 described using Figures 1 to 7. The defogger 120M has a bypass bus bar 150M instead of the bypass bus bars 150L and 150R described using Figures 1 to 7.

[0120] In other words, the vehicle window glass 100M has a configuration in which the bypass bus bars 150L and 150R of the vehicle window glass 100 are replaced with the bypass bus bar 150M shown in Figure 8. The vehicle window glass 100M uses the bypass bus bar 150M as the left and right bypass bus bars. Figure 8 shows the right-side power supply terminal 135R and bypass bus bar 150M, so the differences from the bypass bus bar 150R will be explained.

[0121] The bypass busbar 150M is integrally formed with the power supply terminal 135R shown in Figure 3. The portion of the bypass busbar 150M corresponding to terminal 152A of the bypass busbar 150R shown in Figure 3 is integrated with terminal 135A2 of the power supply terminal 135R. The bypass busbar 150M can be manufactured, for example, by bending sheet metal. Alternatively, the bypass busbar 150M may be made of casting.

[0122] Thus, the boundary between the integrated power supply terminal 135R and the bypass bus bar 150M is located at the +Y direction end of the bypass bus bar 150M, spaced apart from the second bus bar 130R in the +Z direction.

[0123] A terminal 152B is provided at the -Y direction end of the bypass busbar 150M, and is connected to the connection point 133R of the second busbar 130R.

[0124] The current flow in the vehicle window glass 100M, including such a bypass busbar 150M, is the same as the current flow described for the vehicle window glass 100 using Figure 7.

[0125] <Effects> The vehicle window glass 100 of the present disclosure includes a glass plate 110 for a vehicle window and a defogger 120 provided on the glass plate 110, the defogger 120 includes a first bus bar 130L extending in the vertical direction of the glass plate 110, a second bus bar 130R extending in the vertical direction of the glass plate 110, a power supply terminal 135L connected to the first bus bar 130L, a power supply terminal 135R connected to the second bus bar 130R, and the first bus bar - The first conductive member (bypass busbar 150L) comprises a plurality of heating wires 140 connected between the first busbar 130L and the second busbar 130R and extending in the left-right direction of the glass plate 110, a first terminal 152A connected to the power supply terminal 135L, a second terminal 152B connected to the first busbar 130L, and a first main body portion 151 connecting the first terminal 152A and the second terminal 152B and spaced apart from the first busbar 130L. As a result, the number of power supply points supplying power to the first busbar 130L increases, making it easier to equalize the power density of the plurality of heating wires 140. In addition, since the number of heating wires 140 receiving power downward from the added power supply point (terminal 152B) can be reduced, the temperature rise of the first busbar 130L can be suppressed.

[0126] Therefore, it is possible to provide a vehicle window glass 100 that can achieve both equalization of power density in multiple heating elements 140 and suppression of temperature rise in the busbar (first busbar 130L) at a more advanced level.

[0127] Furthermore, since it is possible to manufacture the device simply by adding a first conductive member (bypass busbar 150L) without changing the line width or thickness of the first busbar 130L, the configuration is simple and easy to manufacture.

[0128] Furthermore, the vehicle window glass 100 is simple in structure because it can be realized simply by providing a first conductive member (bypass busbar 150L). For example, there is a busbar manufacturing method (two-stage printing method) in which the busbar is made thicker by printing a paste containing a conductive metal on top of a busbar made by printing a paste containing a conductive metal, thereby reducing the resistance value of the busbar. However, the two-stage printing method increases manufacturing costs due to a significant increase in the manufacturing process. In contrast, the vehicle window glass 100 including the first conductive member (bypass busbar 150L) has the advantage of being easy to manufacture and reducing manufacturing costs.

[0129] Furthermore, the power supply terminal 135L is provided overlapping the first busbar 130L, and the first conductive member (bypass busbar 150L) may be made of sheet metal or casting with the first terminal 152A and the second terminal 152B at both ends. By providing the power supply terminal 135L overlapping the first busbar 130L, the power supply terminal 135L can be positioned as close to the first busbar 130L as possible, enabling an electrically stable arrangement. Also, because the power supply terminal 135L is located in the shadow of the first busbar 130L, the glass plate 110 becomes less noticeable when viewed from the outside of the vehicle, resulting in a better appearance. In addition, the first conductive member (bypass busbar 150L) made of sheet metal or casting can be easily manufactured. Furthermore, by constructing the first conductive member (bypass busbar 150L) from sheet metal or casting, the first conductive member (bypass busbar 150L) is less prone to deformation, enabling stable operation over a long period of time and improving electrical reliability.

[0130] Furthermore, the first conductive member (bypass busbar 150L) may be provided in a position that overlaps with the first busbar 130L in a plan view. By providing the first conductive member (bypass busbar 150L) on top of the first busbar 130L, the first conductive member (bypass busbar 150L) can be positioned as close to the first busbar 130L as possible, enabling an electrically stable arrangement. In addition, because the first conductive member (bypass busbar 150L) is located in the shadow of the first busbar 130L, the glass plate 110 becomes less noticeable when viewed from the outside of the vehicle, resulting in a better appearance.

[0131] Furthermore, the first conductive member (bypass busbar 150L) may have a bent portion 153 on the second terminal 152B side that is bent toward the first busbar 130L. When the heights of the first terminal 152A and the second terminal 152B are different, the height of the first conductive member (bypass busbar 150L) can be adjusted, and a stable configuration can be obtained.

[0132] Furthermore, the distance at which the first conductive member (bypass busbar 150L) separates from the first busbar 130L in the thickness direction of the first busbar 130L may be 0.5 mm or more and 3.0 mm or less. A stable configuration can be obtained by having the height of the first conductive member (bypass busbar 150L) relative to the first busbar 130L be at an appropriate height.

[0133] Furthermore, the distance between the first terminal 152A and the second terminal 152B of the first conductive member (bypass busbar 150L) may be 15 mm or more and 200 mm or less. A stable configuration can be obtained by having an appropriate length for the first conductive member (bypass busbar 150L).

[0134] Furthermore, the power supply terminal 135L and the first conductive member (bypass busbar 150L) may be integrally formed and made of sheet metal or casting. By making the power supply terminal 135L and the first conductive member (bypass busbar 150L) integrally formed from sheet metal or casting, a stable configuration with a reduced number of parts can be achieved at a higher level, while simultaneously equalizing the power density in the multiple heating elements 140 and suppressing the temperature rise of the busbar (first busbar 130L).

[0135] Furthermore, N (where N is an integer of 2 or more) of the multiple heating elements 140 may be connected to the first busbar 130L between the power supply terminal 135L and the connection point 133L where the second terminal 152B is connected to the first busbar 130L. By connecting N (where N is an integer of 2 or more) heating elements 140 in the portion between the second power supply point (terminal 135A2) and the third power supply point (terminal 152B), the amount of current in the first busbar 130L below the third power supply point (terminal 152B) can be reduced, thereby achieving a higher level of suppression of the temperature rise of the busbar (first busbar 130L).

[0136] Furthermore, the first terminal 152A of the first conductive member (bypass busbar 150L) may be connected to the power supply terminal 135L by solder or conductive adhesive. Soldering or conductive adhesive allows for a stable connection of the first terminal 152A to the power supply terminal 135L.

[0137] Furthermore, the second terminal 152B of the first conductive member (bypass busbar 150L) may be connected to the first busbar 130L by solder or conductive adhesive. Soldering or conductive adhesive allows for a stable connection of the second terminal 152B to the first busbar 130L.

[0138] Furthermore, the first terminal 152A or the power supply terminal 135L of the first conductive member (bypass busbar 150L) may have a mechanical joint that mechanically connects the first terminal 152A and the power supply terminal 135L. This allows for a stable connection between the first terminal 152A and the power supply terminal 135L.

[0139] Furthermore, the defogger 120 may further include a second conductive member (bypass busbar 150R) comprising a third terminal 152A connected to the power supply terminal 135R, a fourth terminal 152B connected to the second busbar 130R, and a second main body portion 151 connecting the third terminal 152A and the fourth terminal 152B and spaced apart from the second busbar 130R. This makes it easier to equalize the power density across the multiple heating elements 140, and enables a higher level of suppression of temperature rise in the first busbar 130L and the second busbar 130R.

[0140] The present disclosure is a method for manufacturing a vehicle window glass 100, comprising a glass plate 110 for a vehicle window and a defogger 120 provided on the glass plate 110, wherein when assembling the defogger 120 to the glass plate 110, a first bus bar 130L and a second bus bar 130R extending in the vertical direction of the glass plate 110, and a plurality of heating wires 140 connected between the first bus bar 130L and the second bus bar 130R and extending in the left-right direction of the glass plate 110, A conductive member is formed by printing or etching, and power supply terminals 135L and 135R are connected to the first busbar 130L and the second busbar 130R, respectively. The main body 151 of the conductive member, which includes a first terminal 152A, a second terminal 152B, and a main body 151 connecting the first terminal 152A and the second terminal 152B, is separated from the first busbar 130L, and the first terminal 152A and the second terminal 152B are connected to the power supply terminals 135L and the first busbar 130L, respectively. As a result, the number of power supply points that supply power to the first busbar 130L increases, making it easier to equalize the power density of the multiple heating elements 140. In addition, since the number of heating elements 140 that receive power downward from the added power supply points (terminals 152B) can be reduced, the temperature rise of the first busbar 130L can be suppressed.

[0141] Therefore, it is possible to provide a method for manufacturing vehicle window glass 100 that can achieve both equalization of power density in multiple heating elements 140 and suppression of temperature rise in the busbar (first busbar 130L) at a more advanced level.

[0142] Although exemplary vehicle window glass and methods for manufacturing vehicle window glass have been described above, this disclosure is not limited to the specifically disclosed embodiments, and various modifications and changes are possible without departing from the scope of the claims.

[0143] The following additional information is disclosed regarding the above embodiments. (Addendum 1) A vehicle window glass comprising a glass plate for a vehicle window and a defogger provided on the glass plate, wherein the defogger has a first bus bar extending in the vertical direction of the glass plate, a second bus bar extending in the vertical direction of the glass plate, a first power supply terminal connected to the first bus bar, a second power supply terminal connected to the second bus bar, a plurality of heating wires connected between the first bus bar and the second bus bar and extending in the left-right direction of the glass plate, a first terminal connected to the first power supply terminal, a second terminal connected to the first bus bar, and a first conductive member having a main body portion connecting the first terminal and the second terminal and spaced apart from the first bus bar. (Note 2) The vehicle window glass according to Note 1, wherein the first power supply terminal is provided overlapping the first busbar, and the first conductive member is made of sheet metal or casting with the first terminal and the second terminal at both ends. (Note 3) The vehicle window glass according to Note 2, wherein the first conductive member is provided in a position that overlaps the first busbar in a plan view. (Note 4) The vehicle window glass according to Note 2 or 3, wherein the first conductive member has a bent portion on the second terminal side that is bent toward the first busbar. (Note 5) The vehicle window glass according to any one of Notes 1 to 4, wherein the distance at which the first conductive member is separated from the first busbar in the thickness direction of the first busbar is 0.5 mm or more and 3.0 mm or less. (Note 6) The vehicle window glass according to any one of Notes 1 to 5, wherein the length between the first terminal and the second terminal of the first conductive member is 15 mm or more and 200 mm or less. (Note 7) The vehicle window glass according to any one of Notes 1 to 6, wherein the first power supply terminal and the first conductive member are integrally formed and made of sheet metal or casting. (Note 8) The vehicle window glass according to any one of Notes 1 to 7, wherein N (N is an integer of 2 or more) of the plurality of heating wires are connected to the first busbar between the first power supply terminal and the connection point where the second terminal is connected to the first busbar.(Note 9) The vehicle window glass according to any one of Notes 1 to 8, wherein the first terminal of the first conductive member is connected to the first power supply terminal by solder or conductive adhesive. (Note 10) The vehicle window glass according to any one of Notes 1 to 9, wherein the second terminal of the first conductive member is connected to the first bus bar by solder or conductive adhesive. (Note 11) The vehicle window glass according to any one of Notes 1 to 8, wherein the first terminal of the first conductive member, or the first power supply terminal, has a mechanical joint that mechanically joins the first terminal and the first power supply terminal. (Note 12) The vehicle window glass according to any one of Notes 1 to 11, further comprising a second conductive member having a third terminal connected to the second power supply terminal, a fourth terminal connected to the second bus bar, and a second main body portion connecting the third terminal and the fourth terminal and spaced apart from the second bus bar. (Note 13) A method for manufacturing a vehicle window glass, comprising a glass plate for a vehicle window and a defogger provided on the glass plate, wherein when assembling the defogger to the glass plate, a first bus bar and a second bus bar extending in the vertical direction of the glass plate, and a plurality of heating wires connected between the first bus bar and the second bus bar and extending in the left-right direction of the glass plate are formed by printing or etching; a first power supply terminal and a second power supply terminal are connected to the first bus bar and the second bus bar, respectively; and the first terminal and the second terminal are connected to the first power supply terminal and the first bus bar, respectively, with the main body of a conductive member having a first terminal, a second terminal, and a main body connecting the first terminal and the second terminal separated from the first bus bar.

[0144] Furthermore, the disclosure of Japanese Patent Application No. 2024-167335, filed on 26 September 2024, is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually described as being incorporated by reference.

[0145] 100 Vehicle window glass 110 Glass plate 110B Lower edge 110L Left edge 110R Right edge 110U Upper edge 111 Main surface 113 Anti-fogging area 115 Shielding layer 115A Opening 120 Defogger 130L First bus bar 130R Second bus bar 131L, 131R Upper end 132L, 132R Lower end 135L, 135R Power supply terminal 140 Heating element 150L Bypass bus bar (example of first conductive member) 150R Bypass bus bar (example of second conductive member) 151 Main body (example of first and second main body) 152A Terminal (example of first and third terminal) 152B Terminal (example of second and fourth terminal)

Claims

1. A vehicle window glass comprising a glass plate for a vehicle window and a defogger provided on the glass plate, wherein the defogger has a first bus bar extending vertically across the glass plate, a second bus bar extending vertically across the glass plate, a first power supply terminal connected to the first bus bar, a second power supply terminal connected to the second bus bar, a plurality of heating wires connected between the first bus bar and the second bus bar and extending horizontally across the glass plate, a first terminal connected to the first power supply terminal, a second terminal connected to the first bus bar, and a first conductive member comprising a first main body portion connecting the first terminal and the second terminal and spaced apart from the first bus bar.

2. The vehicle window glass according to claim 1, wherein the first power supply terminal is provided superimposed on the first busbar, and the first conductive member is made of sheet metal or casting with the first terminal and the second terminal at both ends.

3. The vehicle window glass according to claim 2, wherein the first conductive member is provided in a position that overlaps with the first busbar in a plan view.

4. The vehicle window glass according to claim 2, wherein the first conductive member has a bent portion on the second terminal side that is bent toward the first busbar.

5. The vehicle window glass according to claim 1, wherein the distance at which the first conductive member separates from the first busbar in the thickness direction of the first busbar is 0.5 mm or more and 3.0 mm or less.

6. The vehicle window glass according to claim 1, wherein the length between the first terminal and the second terminal of the first conductive member is 15 mm or more and 200 mm or less.

7. The vehicle window glass according to claim 1, wherein the first power supply terminal and the first conductive member are integrally formed and made of sheet metal or casting.

8. A vehicle window glass according to any one of claims 1 to 7, wherein N (where N is an integer of 2 or more) of the plurality of heating elements are connected to the first bus bar between the first power supply terminal and the connection point where the second terminal is connected to the first bus bar.

9. The first terminal of the first conductive member is connected to the first power supply terminal by solder or conductive adhesive, as described in claim 1.

10. The vehicle window glass according to claim 1, wherein the second terminal of the first conductive member is connected to the first bus bar by solder or conductive adhesive.

11. The vehicle window glass according to claim 1, wherein the first terminal of the first conductive member, or the first power supply terminal, has a mechanical joint portion that mechanically joins the first terminal and the first power supply terminal.

12. The vehicle window glass according to any one of claims 1 to 7, wherein the defogger further comprises a second conductive member having a third terminal connected to the second power supply terminal, a fourth terminal connected to the second busbar, and a second main body portion connecting the third terminal and the fourth terminal and spaced apart from the second busbar.

13. A method for manufacturing a vehicle window glass, comprising a glass plate for a vehicle window and a defogger provided on the glass plate, wherein when assembling the defogger to the glass plate, a first busbar and a second busbar extending in the vertical direction of the glass plate, and a plurality of heating wires connected between the first busbar and the second busbar and extending in the left-right direction of the glass plate are formed by printing or etching; a first power supply terminal and a second power supply terminal are connected to the first busbar and the second busbar, respectively; and the first terminal and the second terminal are connected to the first power supply terminal and the first busbar, respectively, with the first main body of a conductive member having a first terminal, a second terminal, and a first main body connecting the first terminal and the second terminal separated from the first busbar.

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