JP2016141320A - Vehicular window glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique which suppresses the rising of thermal stress in the neighborhood of an edge part of a glass plate even when a thermal line part is separated from the edge part of the glass plate.SOLUTION: A vehicular window glass is provided with a conductive filament part which is formed with a glass plate and a conductive material and is arranged on any surface of the glass plate. Therein, the conductive filament part includes a thermal line part which is separated from an end part of the glass plate and is arranged and has a prescribed pattern so as to heat a predetermined area of the glass plate and a power feeding part which is extended from the neighborhood of the end part of the glass plate, is connected to the thermal line part and feeds power to the thermal line part, and the power feeding part is partially narrowed.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a window glass for a vehicle.

  On the surface of a window glass for a vehicle attached to an automobile or the like, there is a conductive wire portion provided with a heat wire portion for removing condensation or melting ice and a power feed portion for supplying power to the heat wire portion. May be provided. The conductive line portion is formed by printing and baking a conductive paste such as silver on the surface of the window glass.

  As an example of the window glass having such a conductive line portion, for example, in Patent Document 1, the heating wire provided on each of the lower end side and the side end side of the glass plate, and the lower end of the glass plate, There has been proposed a windshield including a conductor pattern having a power supply electrode for supplying power to a heating wire. In this windshield, a heating wire is arranged in a region where a wiper is operated to push out water droplets, ice, snow, frost and the like. And the heat etc. of the heat generating filament can melt the ice adhering to this area | region.

JP2012-140086

  In the window glass as described above, when the hot wire portion is heated, a region heated by the hot wire portion and a region not so formed are generated, and therefore there is a large temperature difference around the region where the hot wire portion is arranged in the glass plate. Arise. As in Patent Document 1, when the heat ray part is arranged near the end part such as the lower end part, the side end part, etc. of the glass plate, when the heat ray part is brought close to the end part of the glass plate, the region where the large temperature difference occurs is also made of glass. It approaches the edge of the board. If it does so, the big temperature difference which arises around this heat ray part will have influence, and the thermal stress which acts on the edge part of a glass plate will become large. Since large thermal stress causes cracks at the edge of the glass plate, the hot wire part is separated from the edge of the glass plate, that is, the region where the large temperature difference occurs is not too close to the edge of the glass plate, Reduction of the thermal stress which acts on the edge part of a glass plate is performed.

  However, the inventor of the present invention has found that the following problems may occur by separating the hot wire portion from the end portion of the glass plate in this way. That is, if the hot wire portion is separated too far from the end portion of the glass plate, the length of the power feeding portion extending from the end portion of the glass plate is increased in order to feed power to the hot wire portion. When heating the hot wire portion, since the current flowing through the hot wire portion also flows through the power feeding portion, the power feeding portion also generates heat. When the length of the power feeding unit is increased, the region heated by the power feeding unit is widened. The inventor of the present invention has found that the thermal stress acting on the vicinity of the end portion of the glass plate provided with the power feeding portion increases due to this influence.

  In one aspect, the present invention has been made in view of such circumstances, and the purpose thereof is to increase the thermal stress in the vicinity of the end portion of the glass plate even if the heat ray portion is separated from the end portion of the glass plate. It is to provide technology to suppress.

  The present invention employs the following configuration in order to solve the above-described problems.

  That is, the window glass according to one aspect of the present invention is a window glass for a vehicle that is formed of a glass plate and a conductive material and includes a conductive line portion disposed on any surface of the glass plate. The conductive line portion is disposed away from the end portion of the glass plate, and has a heat line portion having a predetermined pattern so as to heat a predetermined region of the glass plate, and from the vicinity of the end portion of the glass plate. A power supply unit that extends and is connected to the heat line unit and supplies power to the heat line unit. The power feeding unit is partially thinned.

  According to this configuration, the power feeding unit is partially thinned. That is, the power supply part has a partially narrowed line width. When the line width is narrowed, the resistance value at that portion increases, so that generally the amount of heat generated at the portion where the line width is narrowed becomes large. On the other hand, in the whole power feeding part, the area | region which heats a glass plate becomes narrow, in other words, the area | region which thermally radiates the heat | fever of a power feeding part becomes wide. Therefore, even if the heat generation amount partially increases in the power feeding unit, it is possible to dissipate heat more than the increase in the heat generation amount. Therefore, according to the configuration, even if the length of the power feeding unit is increased by separating the heat ray part from the end of the glass plate, the amount of heat generated in the entire power feeding unit can be suppressed. An increase in thermal stress in the vicinity of the end can be suppressed.

  It should be noted that the predetermined pattern of the heat ray portion can be appropriately determined according to the embodiment. Moreover, silver, gold | metal | money, platinum etc. may be sufficient as an electroconductive material, for example, and if the said use of an electroconductive wire | line part can be achieved, it may be suitably selected according to embodiment. Further, the vicinity of the end of the glass plate may be in a state of being in contact with the end of the glass plate, or in a state of being separated from the end of the glass plate to such an extent that wiring from the power source of the vehicle can be connected. There may be. The region near the end of the glass plate includes a region where the thermal stress generated at the end of the glass plate can increase due to heat generated by the power feeding unit.

  Moreover, as another form of the window glass according to the one side surface, the power feeding portion includes a base portion disposed near an end portion of the glass plate, a thin wire portion having a line width narrower than the base portion and extending from the base portion, You may have. According to the said structure, the electric power feeding part becomes thin at the front end side, and can suppress the quantity of the heat | fever generate | occur | produced around the part. Thereby, an increase in thermal stress in the vicinity of the end of the glass plate can be suppressed.

  Further, as another form of the window glass according to the one aspect, a plurality of the thin wire portions may be provided, the plurality of thin wire portions may be separated from each other, and the heat ray portion may be any of the plurality of thin wire portions. You may be comprised so that it may be electrically fed by connecting to. According to the said structure, the connection with the heat ray part of various aspects becomes easy, and the freedom degree of design of an electroconductive wire | line part can be raised.

  Moreover, as another form of the window glass according to the one aspect, the heat ray portion may be divided and connected to each of the plurality of thin wire portions. Of the conductive filament parts, the hot wire part is a region having a high calorific value. According to the said structure, this heat ray part is divided | segmented and connected in a some thin wire | line part. Here, since the plurality of thin wire portions are separated from each other, the connecting portion between the heat wire portion and each thin wire portion can be separated. That is, since the region where the heat generation amount is high can be separated, according to the configuration, the amount of heat generated in the vicinity of the power feeding unit can be suppressed, thereby increasing the thermal stress in the vicinity of the end of the glass plate. Can be suppressed.

  Moreover, as another form of the window glass according to the one side surface, a distance separating the plurality of thin wire portions from each other may be longer than a line width of each of the plurality of thin wire portions. According to the said structure, the width | variety of the area | region between adjacent thin wire | line parts is comprised longer than the line width of each thin wire | line part. Therefore, it is possible to sufficiently secure the size of the region between adjacent thin wire portions, and the heat generated in each thin wire portion can be sufficiently radiated by this region. Therefore, according to the said structure, the temperature rise of the whole electric power feeding part can be suppressed, and, thereby, the raise of the thermal stress in the edge part vicinity of a glass plate can fully be suppressed.

  Moreover, as another form of the window glass according to the one side surface, the base portion of the power feeding unit may be disposed so as to be in contact with an end portion of the glass plate. The base part of the power feeding unit is a part having a large line width, and is connected to a wiring from the power source of the vehicle. According to the said structure, since this base is arrange | positioned so that the edge part of a glass plate may be contacted, the connection of the wiring from the power supply of a vehicle becomes easy.

  Moreover, as another form of the window glass according to the one aspect, the conductive material may include silver. Silver has high conductivity, is relatively easily available, and is inexpensive. Therefore, according to the said structure, a good quality conductive filament part can be formed at low cost.

  Moreover, the said window glass may be utilized as a windshield of a motor vehicle as another form of the window glass which concerns on the said one side surface. Glass plates used for automotive windshields are generally not tempered. When the glass plate is not strengthened, the glass plate is relatively easily cracked by the thermal stress generated at the end of the glass plate. On the other hand, according to the said structure, the raise of the thermal stress in the edge part vicinity of a glass plate can be suppressed. Therefore, even if the glass plate is not tempered, the possibility of cracking can be reduced. Strengthening means, for example, by heating the glass plate to about 700 ° C. and then rapidly cooling the glass plate to give a compression layer on the surface of the glass plate, so that the strength of the glass plate is about 3 to 5 times. Is to increase.

  According to the present invention, an increase in thermal stress in the vicinity of the end portion of the glass plate can be suppressed even if the hot wire portion is separated from the end portion of the glass plate.

FIG. 1 is a plan view schematically illustrating a window glass according to the embodiment. FIG. 2 is a partial enlarged view schematically illustrating the power feeding unit according to the embodiment. FIG. 3 schematically illustrates a window glass manufacturing process according to the embodiment. FIG. 4 is a partially enlarged view schematically illustrating a power feeding unit according to another embodiment. FIG. 5 is a partial enlarged view schematically illustrating a power feeding unit according to another embodiment. FIG. 6 is a plan view schematically illustrating a heat ray portion according to another embodiment. FIG. 7 shows a temperature distribution in the vicinity of the power feeding part when the hot wire part of the window glass according to the reference example is heated. FIG. 8 shows a thermal stress distribution in the vicinity of the power feeding part when the hot wire part of the window glass according to the reference example is heated. FIG. 9 shows a temperature distribution in the vicinity of the power feeding part when the hot wire part of the window glass according to the comparative example is heated. FIG. 10 shows a thermal stress distribution in the vicinity of the power feeding portion when the hot wire portion of the window glass according to the comparative example is heated. FIG. 11 shows a temperature distribution in the vicinity of the power feeding part when the hot wire part of the window glass according to the example is heated. FIG. 12 shows a thermal stress distribution in the vicinity of the power feeding portion when the hot wire portion of the window glass according to the example is heated.

  Hereinafter, an embodiment according to an aspect of the present invention (hereinafter, also referred to as “this embodiment”) will be described with reference to the drawings. However, this embodiment described below is only an illustration of the present invention in all respects. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. That is, in implementing the present invention, a specific configuration according to the embodiment may be adopted as appropriate.

§1 Configuration example First, the window glass 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a plan view schematically illustrating a window glass 1 according to this embodiment. For convenience of explanation, the up and down direction in FIG. 1 is referred to as “up and down”, and the left and right direction in FIG. 1 is referred to as “left and right”. FIG. 1 illustrates a window glass 1 viewed from the inside of the vehicle. That is, the back side of the sheet of FIG. 1 is the outside of the vehicle, and the front side of the sheet of FIG. 1 is the inside of the vehicle.

  The window glass 1 according to the present embodiment is a window glass for a vehicle attached to an automobile, and specifically, a windshield of the automobile. As illustrated in FIG. 1, the window glass 1 includes a glass plate 10 having a substantially rectangular shape, and is attached to an automobile with a slight inclination from the vertical. The glass plate 10 includes an upper end 11 extending in the left-right direction, a lower end 12 facing the upper end 11 and slightly curved, a right end 13 connecting the right ends of the upper end 11 and the lower end 12, and an upper end. And left end 14 connecting the left ends of portion 11 and lower end 12.

  On the inner surface of the glass plate 10, a shielding layer 3 that shields the field of view from the outside of the vehicle is provided along the peripheral portion of the glass plate 10. On the shielding layer 3, the conductive line portion 2 having a predetermined pattern is formed from the lower end portion 12 to the left end portion 14. Hereinafter, each of these components will be described.

<Glass plate>
First, the glass plate 10 will be described. The glass plate 10 which concerns on this embodiment is utilized as a window glass of a motor vehicle, and is comprised by the shape according to the window frame of the motor vehicle attached. In the present embodiment, the glass plate 10 has a substantially rectangular shape in plan view, and in side view, the inner surface is concave and the outer surface is convex from the periphery to the center. It is formed in a curved shape.

  Such a glass plate 10 can have various configurations according to the embodiment. As the glass plate 10, a known glass plate for automobiles can be used. For example, the glass plate 10 may be heat ray absorbing glass, general clear glass or green glass, or UV green glass. However, such a glass plate 10 needs to realize visible light transmittance in accordance with the safety standards of the country where the automobile is used. For example, the solar radiation absorptivity and visible light transmittance can be adjusted to satisfy safety standards. Below, an example of a composition of clear glass and an example of a heat ray absorption glass composition are shown.

(Clear glass)
SiO ₂ : 70 to 73% by mass
Al ₂ O ₃ : 0.6 to 2.4% by mass
CaO: 7 to 12% by mass
MgO: 1.0 to 4.5 mass%
R ₂ O: 13 to 15% by mass (R is an alkali metal)
Fe total iron oxide in terms of _{2 O 3 (T-Fe 2} O 3): 0.08~0.14 wt%

(Heat ray absorbing glass)
The composition of the heat-absorbing glass, for example, based on the composition of the clear glass, the proportion of the total iron oxide in terms of _{Fe 2 O 3 (T-Fe} 2 O 3) and 0.4 to 1.3 wt%, CeO ₂ ratio as 0-2 mass%, the proportion of TiO ₂ and 0 to 0.5 wt%, framework component of the glass (mainly, SiO ₂ and Al ₂ O ₃₎ to T-Fe ₂ O _3, CeO _The composition can be reduced by an increase of ₂ and TiO ₂ .

  In addition, the kind of glass plate 10 is not restricted to clear glass, heat ray absorption glass, etc., According to embodiment, it can select suitably. For example, the glass plate 10 may be an acrylic or polycarbonate resin window.

  Moreover, the thickness of the glass plate 10 which concerns on this embodiment does not need to be specifically limited. However, from the viewpoint of weight reduction, the thickness of the glass plate 10 may be set in the range of 2.2 to 5.1 mm, or may be set in the range of 2.4 to 3.8 mm. You may set in the range of 7-3.2 mm. Furthermore, the thickness of the glass plate 10 may be set to be 3.1 mm or less.

<Shielding layer>
Next, the shielding layer 3 will be described. As illustrated in FIG. 1, in the present embodiment, the shielding layer 3 is formed on the peripheral edge portion of the inner surface of the glass plate 10. The shielding layer 3 is provided so that the attachment portion of the glass plate 10 and the like cannot be seen from the outside of the vehicle. Therefore, the region where the shielding layer 3 is provided can be appropriately selected and set according to the embodiment.

  As long as the field of view from the outside of the vehicle can be shielded, the material of the shielding layer 3 may be appropriately selected according to the embodiment, and a dark ceramic such as black, brown, gray, or dark blue may be used. . For example, a black ceramic is laminated on the inner surface of the glass plate 10 by screen printing or the like, and the laminated ceramic together with the glass plate 10 is heated. Thereby, the shielding layer 3 having a single layer structure can be formed on the peripheral edge of the window glass 1. Note that various materials can be used for the ceramic used for the shielding layer 3. For example, a ceramic having the following composition can be used for the shielding layer 3.

* 1, Main component: Copper oxide, Chromium oxide, Iron oxide and Manganese oxide * 2, Main component: Bismuth borosilicate, Zinc borosilicate

  The thickness of the shielding layer 3 can be set as appropriate. For example, the thickness of the shielding layer 3 can be set in the range of 10 μm to 20 μm. In addition to shielding the field of view from the outside of the vehicle, the shielding layer 3 can prevent deterioration of the adhesive for attaching the glass plate 10 to the vehicle body by cutting ultraviolet rays.

<Conductive wire section>
Next, the conductive filament 2 will be described with reference to FIG. FIG. 2 is a partial enlarged view illustrating the power feeding portions 23 to 25 of the conductive linear portion 2. As illustrated in FIG. 1 and FIG. 2, the conductive linear portion 2 according to the present embodiment is disposed on the inner surface of the glass plate 10 via the shielding layer 3. And this electroconductive wire | line part 2 is electrically fed to two hot wire parts (21, 22) which have a predetermined pattern, and each hot wire part (21, 22) so that the predetermined area | region of the glass plate 10 may be heated. For this purpose, three power supply units 23 to 25 are provided.

  The hot wire portion 21 is disposed away from the lower end portion 12 and is provided along the lower end portion 12 from a slightly right side of the center of the glass plate 10 to the vicinity of the right end portion 13. Further, the heat ray portion 22 is arranged away from the lower end portion 12 and extends along the lower end portion 12 from the slightly right side of the center of the glass plate 10 to the vicinity of the left end portion 14, and then from the vicinity of the lower end portion 12 to the upper end portion. 11 extends to the vicinity of 11 along the left end 14. The region where each heat ray portion (21, 22) is provided corresponds to a standby position and a reverse position of a wiper (not shown). Such a pattern of each heat ray part (21, 22) can be appropriately changed according to the embodiment.

  On the other hand, in order to supply electric power to the respective heat ray portions (21, 22), the respective electric power supply portions 23 to 25 extend upward from the lower end portion 12 of the glass plate 10 and are connected to the respective heat ray portions (21, 22). The power feeding units 23 and 25 are positive electrodes, and the power feeding unit 24 is a negative electrode. Therefore, the power supply unit 23 is connected to the heat wire unit 21, and the power supply unit 25 is connected to the heat wire unit 22. Moreover, the electric power feeding part 24 is connected with both hot-wire parts (21, 22).

  A harness 4 having three terminal portions is attached to each of the power supply units 23 to 25 by soldering or the like, and wiring (not shown) from the power source of the automobile is connected to each of the power supply units 23 to 25 through this harness. The Therefore, the driver of the automobile can supply electricity to the conductive wire portion 2 by operating an operation panel (not shown).

  When electricity is supplied to the conductive wire portion 2, current is generated in each heat wire portion (21, 22) via each power feeding portion 23 to 25. If it does so, each heat ray part (21, 22) will be heated by the energy of the electricity which flows, and the glass plate 10 will be warmed in the area | region in which this each heat ray part (21, 22) was formed. As a result, the frozen wiper can be warmed, and the ice and the like adhering to this area can be melted.

  However, each heat ray part (21, 22) is provided apart from the lower end part 12 of the glass plate 10 in which the electric power feeding parts 23-25 are arrange | positioned. Therefore, when each heat ray part (21, 22) is separated too much from the lower end part 12, the length of each electric power feeding parts 23-25 will become long. Then, as described above, the thermal stress in the vicinity of the end portions of the respective power feeding portions 23 to 25, that is, in the vicinity of the region where the power feeding portions 23 to 25 are provided in the lower end portion 12 of the glass plate 10 increases. This may cause cracks. On the other hand, in this embodiment, the calorific value of each electric power feeding part 23-25 is suppressed by subdividing each electric power feeding part 23-25. This suppresses an increase in thermal stress in the vicinity of this region and reduces the possibility of cracking. Hereinafter, each configuration will be described in detail.

(Power supply unit)
First, each of the power feeding units 23 to 25 will be described. Each electric power feeding part 23-25 is arrange | positioned in the lower end part 12 vicinity of the glass plate 10, is extended in a surface direction inner side, and is connected with each heat ray part (21, 22). Each of the power supply units 23 to 25 is partially thinned. Specifically, the power supply unit 23 includes a rectangular base 230 having a wide and rectangular shape that is disposed near the lower end 12 of the glass plate 10, and extends upward from the base 230 and has a narrower line width than the base 230. And a thin wire portion 231.

  The power feeding unit 24 includes a base 240 similar to the base 230, and four thin line portions 241 to 244 that extend upward from the end of the base 240 and have a narrower line width than the base 240. Each thin wire | line part 241-244 is formed in the rectangular shape, and is mutually spaced apart and arrange | positioned in the left-right direction.

  However, the thin line portion 244 is configured to have a larger line width than the other thin line portions 241 to 243, bends to the right in the vicinity of the base portion 240, and then extends upward. The fine wire portion 243 is connected to the bent portion of the fine wire portion 244. As described above, the thin line portion may branch in the middle of extension.

  The power supply unit 25 includes a base portion 250 similar to the base portion 230 and the base portion 240, and three thin wire portions 251 to 253 each extending upward from an end portion of the base portion 250 and having a line width narrower than that of the base portion 250. ing. Each thin wire | line part 251-253 is formed in the rectangular shape, and is mutually spaced apart and arrange | positioned in the left-right direction. Among such thin wire portions 251 to 253, the thin wire portion 251 is configured to have a larger line width than the other thin wire portions (252, 253).

  Each terminal part of the harness 4 is attached to each base part (230, 240, 250) of each electric power feeding part 23-25. Therefore, each base (230, 240, 250) is configured to have a certain line width so as to withstand a large current from the power source of the automobile.

  For example, from the viewpoint of connectivity with the harness 4, the width of each base portion (230, 240, 250) of each of the power feeding portions 23 to 25 is preferably set in the range of 10 mm to 20 mm. However, the width of each base part (230, 240, 250) may not be limited to such a range, and can be appropriately selected according to the embodiment.

  Moreover, it is preferable to arrange | position each base part (230, 240, 250) so that the harness 4 may be adhere | attached so that the edge part (this embodiment lower end part 12) of the glass plate 10 may be contact | connected. However, each base (230, 240, 250) may be slightly separated from the end of the glass plate 10 as long as the harness 4 can be bonded. That is, the vicinity of the end portion of the glass plate 10 may be in a state of being in contact with the end portion of the glass plate 10, and the glass plate 10 may be connected to a wiring (harness 4) from a vehicle power source. The state separated from the edge part may be sufficient. The region in the vicinity of the end portion of the glass plate 10 includes a region in which the thermal stress generated at the end portion of the glass plate 10 can increase due to the heat generated by the power feeding units 23 to 25.

  On the other hand, since each thin line part (231, 241-244, 251 to 253) does not have a request like the above-mentioned each base part (230, 240, 250), the line width can be reduced. However, since the resistance value increases as the line width is reduced, the amount of heat generation generally increases. On the other hand, since the region that cannot be heated by each of the power supply units 23 to 25 is widened, the region that radiates the generated heat is widened. In the present embodiment, by narrowing the line width of each thin wire portion (231, 241-244, 251-253) of each power feeding portion 23-25, it is possible to make use of the fact that such a heat dissipating region widens, The amount of heat generated by the power feeding units 23 to 25 is suppressed.

  For example, from the viewpoint of suppressing the amount of heat generated in each of the power supply units 23 to 25 while supplying an appropriate amount of current to each of the hot wire units (21, 22), each of the thin wire units (231, 241, 244, 251 to 253) The width is preferably set in the range of 1 mm to 10 mm. Furthermore, it is more preferable that the width of each thin line portion (231, 241-244, 251-253) is set to 5 mm or less. However, the width of each thin line part (231, 241-244, 251-253) does not need to be limited to such a range, and can be appropriately selected according to the embodiment.

  In addition, you may comprise the distance which each thin wire | line part (231, 241-244, 251-253) mutually separates, ie, the distance between adjacent thin wire | line parts, longer than the line | wire width of each thin wire | line part. According to the said structure, the width | variety of the area | region between adjacent thin wire | line parts is comprised longer than the line width of each thin wire | line part (231, 241-244, 251-253). Therefore, it is possible to sufficiently secure the size of the region between adjacent thin wire portions, and the heat generated in each thin wire portion (231, 241-244, 251 to 253) can be sufficiently dissipated by this region. . Therefore, it is possible to suppress an increase in the temperature of the entire power supply units 23 to 25, and thereby sufficiently suppress an increase in thermal stress in the vicinity of the region where the respective power supply units 23 to 25 are provided at the lower end portion 12 of the glass plate 10. Can do.

(Heat wire part)
Next, each heat ray part (21, 22) is demonstrated. In this embodiment, the heat ray part 21 is comprised by two elongate filaments (211 and 212). Each of the filaments (211 and 212) extends along the lower end portion 12 from the vicinity of the upper end of the thin wire portion 231 of the power supply portion 23 toward the right end portion 13 and then turns back once near the right end portion 13 toward the power supply portion 23. Come back. Each of the filaments (211 and 212) is further folded back in the vicinity of the upper portion of the power supply unit 23 and extends along the lower end portion 12 toward the right end portion 13 again. Each of the filaments (211, 212) is folded back again near the right end portion 13, returned toward the power feeding unit 24, and connected to the upper end of the thin wire portion 244 of the power feeding unit 24.

  Moreover, the heat ray part 22 is comprised by the five elongate filaments 221-225. Of these, the three filaments 221 to 223 extend from the vicinity of the upper ends of the thin wire portions 251 to 253 of the power supply portion 25 toward the left end portion 14 along the lower end portion 12 and are folded back in the vicinity of the left end portion 14. Then, the power supply unit 24 returns to the vicinity of the upper ends of the thin wire portions 241 to 243 of the power supply unit 24. On the other hand, the two filaments (224, 225) located on the outside are connected to the lower side of the narrow wire portion 251 of the power feeding unit 25 from the position where the wire strip 221 is connected, and toward the left end 14. It extends along the lower end 12. Each of the filaments (224, 225) is bent near the left end 14 and extends toward the upper end 11 along the left end 14. Then, each of the filaments (224, 225) is folded back near the upper end portion 11, returned again to the vicinity of the lower end portion 12, and further bent near the lower end portion 12 to return toward the power feeding portion 24. It is connected near the upper end of 244.

  In addition, in order to obtain an appropriate calorific value in each heat ray part (21, 22), the line width of each filament (211, 212, 221 to 225) of each heat ray part (21, 22) is 0.5 mm to It is preferable to set in the range of 10 mm. Moreover, as for the line | wire width of each filament (211,212,221-225) of each heat ray part (21,22), it is more preferable to set to 3 mm or less. However, the line width of each filament (211, 212, 221 to 225) of each hot wire part (21, 22) may not be limited to these ranges, and can be appropriately selected according to the embodiment.

(Other)
In the present embodiment, the conductive wire portion 2 is constituted by the heat wire portions (21, 22) and the power feeding portions 23 to 25. Such a conductive filament part 2 is formed by laminating | stacking the electroconductive material which has electroconductivity on the inner surface of the glass plate 10, more specifically on the shielding layer 3. FIG. The material of the conductive filament part 2 should just have electroconductivity, and can be suitably selected for embodiment. As an example of the material of the conductive filament part 2, silver, gold, platinum, etc. can be mentioned. For example, the conductive line portion 2 can be formed by printing and baking a conductive silver paste containing silver powder, glass frit and the like on the shielding layer 3. Silver is highly conductive, relatively easily available, and inexpensive. Therefore, in order to form the conductive line portion 2 with good quality at low cost, the conductive material preferably contains silver.

§2 Manufacturing method Next, the manufacturing method of the window glass 1 which concerns on this embodiment is demonstrated using FIG. FIG. 3 schematically illustrates a shaping process of the glass plate 10 according to the present embodiment. In addition, the manufacturing process of the window glass 1 demonstrated below is only an example, and each manufacturing process may be changed as much as possible. Further, in the manufacturing process described below, steps can be omitted, replaced, and added as appropriate according to the embodiment.

  As illustrated in FIG. 3, in this production line, a heating furnace 901 and a molding device 902 are arranged in this order from upstream to downstream. And the roller conveyor 903 is arrange | positioned from the heating furnace 901 to the shaping | molding apparatus 902 and its downstream, The glass plate 10 used as a process target is conveyed by this roller conveyor 903.

  The glass plate 10 is formed in a flat plate shape before being carried into the heating furnace 901. And a black ceramic is laminated | stacked on the peripheral part of the surface inside the vehicle which concerns on the glass plate 10 by screen printing etc., and calcining for about 20 minutes is performed at about 200 degreeC. Thereby, the shielding layer 3 is formed on the peripheral edge of the flat glass plate 10. In addition, after the shielding layer 3 is formed, a conductive silver paste containing silver powder, glass frit and the like is printed on the shielding layer 3 so as to form the pattern of the conductive line portion 2. Thereafter, the glass plate 10 is carried into the heating furnace 901.

  The heating furnace 901 can have various configurations. For example, the heating furnace 901 can be an electric heating furnace. The heating furnace 901 includes a rectangular tube-shaped furnace main body whose upstream and downstream ends are open, and a roller conveyor 903 is disposed in the interior from upstream to downstream. Heaters (not shown) are disposed on the upper surface, the lower surface, and the pair of side surfaces of the inner wall surface of the furnace body, respectively, and the temperature at which the glass plate 10 passing through the heating furnace 901 can be formed, for example, the softening point of glass. Heat to near. For example, the heating furnace 901 heats the glass plate 10 at about 650 ° C. As a result, the glass plate 10 can be molded, and the silver paste is baked to form the conductive line portion 2.

  The forming apparatus 902 is configured to press a glass plate with an upper die 921 and a lower die 922 to form a predetermined shape. The upper die 921 has a downwardly convex curved shape that covers the entire upper surface of the glass plate 10 and is configured to be movable up and down. The lower mold 922 is formed in a frame shape corresponding to the peripheral edge of the glass plate 10, and the upper surface thereof has a curved shape so as to correspond to the upper mold 921. With this configuration, the glass plate 10 is press-formed between the upper die 921 and the lower die 922, and formed into a final curved shape. A roller conveyor 903 is disposed in the frame of the lower mold 922, and the roller conveyor 903 can move up and down so as to pass through the frame of the lower mold 922. And although illustration is abbreviate | omitted, the slow cooling apparatus (illustration omitted) is arrange | positioned in the downstream of the shaping | molding apparatus 902, and the shape | molded glass plate 10 is cooled. Thereby, the window glass 1 is produced.

[Feature]
In the window glass 1 which concerns on this embodiment, each electric power feeding parts 23-25 are thinned. Specifically, each of the power supply units 23 to 25 has a narrow line width on the tip side by the thin line portions (231, 241 to 244, 251 to 253). When the line width becomes narrower, the resistance value at that portion increases, so that generally the amount of heat generated at each thin line portion (231, 241-244, 251-253) increases. On the other hand, a gap is provided between the thin wire portions (231, 2241 to 244, 251 to 253), that is, the region heated by each of the power feeding portions 23 to 25 becomes narrow, and the region that dissipates the generated heat is wide. Become. Therefore, according to the present embodiment, even if the amount of heat generation partially increases in each thin wire portion (231, 241-244, 251 to 253), heat is dissipated in each gap more than the amount of increase in the amount of heat generation. Is possible. Therefore, according to the said structure, even if each heat ray part (21, 22) is pulled away from the lower end part 12 of the glass plate 10, and the length of each electric power feeding parts 23-25 becomes long, in each electric power feeding part 23-25 whole. The amount of heat generated can be suppressed. As a result, an increase in thermal stress in the vicinity of the region where the power feeding portions 23 to 25 are provided in the lower end portion 12 of the glass plate 10 can be suppressed.

  In the present embodiment, a plurality of thin line portions (231, 2241 to 244, 251 to 253) are provided. Therefore, various connection with each filament (211, 212, 221 to 225) of each heat wire part (21, 22) and each thin wire part (231, 241 to 244, 251 to 253) becomes possible, and the conductive wire The degree of freedom in designing the strip 2 can be increased.

  Moreover, in this embodiment, each filament (211 and 212, 221 to 225) of each hot wire part (21 and 22) is divided into a plurality of thin wire parts (231, 241 to 244, 251 to 253) and connected. . Among the regions of the conductive wire portion 2, each heat wire portion (21, 22) is a region having a high calorific value, and in particular, each wire (211, 212, 221 to 225) and each thin wire portion (231, 241 to 21). 244, 251-253), the amount of heat generation becomes large. On the other hand, according to the said structure, since each thin wire | line part (231, 241-244, 251-253) is spaced apart, each filament (211, 212, 221-225) and each thin wire | line part (231, 241 to 244 and 251 to 253) can be separated from each other. Thereby, since the area | region where the emitted-heat amount is high can be pulled apart, according to this embodiment, the quantity of the heat | fever generate | occur | produced around each electric power feeding parts 23-25 can be suppressed, and, thereby, the edge part of the glass plate 10 An increase in thermal stress in the vicinity of (lower end portion 12) can be suppressed.

§3 Modifications As described above, the embodiments of the present invention have been described in detail. However, the above description is merely an illustration of the present invention in all respects. It goes without saying that various improvements and modifications can be made without departing from the scope of the present invention. In the following description, the same components as those in the above embodiment are denoted by the same reference numerals, and the description thereof is omitted as appropriate.

(Window glass)
For example, in the said embodiment, the window glass 1 is a windshield for motor vehicles. However, the window glass to which the present invention can be applied is not limited to the windshield of an automobile, and can be appropriately selected according to the embodiment.

  In addition, the glass plate utilized for the windshield for motor vehicles is generally not strengthened. When the glass plate is not strengthened, the glass plate is relatively easily cracked by the thermal stress generated at the end of the glass plate.

  On the other hand, according to the said embodiment, the raise of the thermal stress of the area | region in which the electric power feeding parts 23-25 were provided in the edge part (lower end part 12) of the glass plate 10 can be suppressed. Therefore, even if it is the glass plate 10 which is not strengthened, possibility that a crack will arise can be reduced.

  Strengthening means, for example, by heating the glass plate to about 700 ° C. and then rapidly cooling the glass plate to give a compression layer on the surface of the glass plate, so that the strength of the glass plate is about 3 to 5 times. Is to increase.

(Glass plate)
Further, for example, regarding the specific configuration of the glass plate 10, omission, change, replacement, and addition of components may be appropriately performed according to the embodiment. For example, the glass plate 10 has a shape curved forward, but may be a flat shape. The glass plate 10 is formed in a substantially rectangular shape. However, the shape of the glass plate 10 is not limited to the above embodiment, and can be appropriately selected according to the embodiment.

  The glass plate 10 is composed of a single glass plate. However, the glass plate 10 may be made of laminated glass in which an outer glass plate and an inner glass plate are bonded to each other through an intermediate film. In this case, the conductive line portion 2 may be laminated on the inner surface of the outer glass plate. Moreover, according to this, a notch may be provided in a part of area | region corresponding to the electric power feeding parts 23-25 of an inner side glass plate so that the harness 4 can be attached to the electric power feeding parts 23-25. .

  In addition, when the conductive filament part 2 is laminated | stacked on the vehicle inner surface of an outer side glass plate in this way, if each electric power feeding part 23-25 leaves | separates in the surface direction inner side from the edge part vicinity of an outer side glass plate, inner side glass will be carried out. The notch provided in the area | region corresponding to the electric power feeding parts 23-25 of a board will become large only by that distance.

  In order to prevent the notch provided in the inner glass plate from becoming large, a method of reducing the radius of curvature of the notch can be considered, but it is technically necessary to provide such a notch with a small radius of curvature in the inner glass plate. It is difficult to. Therefore, it is difficult to avoid an increase in the notch provided in the inner glass plate when each of the power feeding units 23 to 25 is separated from the vicinity of the end of the outer glass plate inward in the surface direction.

  And when a notch becomes large, the intensity | strength of an inner side glass plate will fall, and the whole glass plate will become easy to break. In addition, a sealing material is applied to the periphery of the notch in order to maintain airtightness. However, if the notch becomes large, the amount of the sealing material used increases and the manufacturing cost increases. End up.

  Therefore, for these reasons, when the glass plate 10 is used as a windshield and the glass plate 10 is made of laminated glass, each power supply is separated from the end portion of the outer glass plate inward in the plane direction. Providing the parts 23 to 25 is avoided. That is, each of the power feeding units 23 to 25 is provided in the vicinity of the end of the outer glass plate, in particular, in contact with or near the end of the outer glass plate.

(Shielding layer)
For example, in the said embodiment, the shielding layer 3 is provided so that the peripheral part of the window glass 1 may be followed. However, the region where the shielding layer 3 is provided can be set as appropriate according to the embodiment. However, if the shielding layer 3 overlaps with the driver's visual field range, the driver's field of view is obstructed by the shielding layer 3 during driving. Therefore, it is preferable to set the region of the shielding layer 3 so as not to overlap the driver's visual field range. The shielding layer 3 may be omitted. In this case, the conductive line portion 2 is directly laminated on the surface of the glass plate 10.

  Further, for example, in the above embodiment, the shielding layer 3 has a single layer structure. However, the shielding layer 3 can have a multilayer structure. For example, the first ceramic layer is formed by laminating ceramics on the inner surface of the glass plate 10. Next, a silver layer is formed by laminating silver on the first ceramic layer. Furthermore, a second ceramic layer is formed by laminating a ceramic on the silver layer. As a result, the shielding layer 3 having a three-layer structure can be formed. The three-layer shielding layer 3 can shield electromagnetic waves by a silver layer. In addition, the material of the composition shown in the following Table 2 can be utilized for this silver layer.

* 1, Main component: Bismuth borosilicate, Zinc borosilicate

  Further, for example, in the above embodiment, the shielding layer 3 is laminated on the inner surface of the glass plate 10. However, the surface on which the shielding layer 3 is laminated may not be limited to the vehicle inner surface, but may be the vehicle outer surface. Moreover, when the glass plate 10 is comprised with a several glass plate, the 1 or several surface which laminates | stacks the shielding layer 3 may be suitably selected from the surface of a several glass plate.

  In addition, the adhesiveness at the time of attaching the window glass 1 to a motor vehicle can be improved by laminating | stacking a ceramic on the surface inside the vehicle of the glass plate 10. FIG. Moreover, it can prevent that the window glass 1 becomes easy to be broken in an attachment part by this shielding layer 3 becoming a cushion between the glass plate 10 and the attachment part of a motor vehicle.

(Conductive wire)
In addition, regarding the above-described specific configuration of the conductive linear portion 2, the components may be appropriately omitted, changed, replaced, and added according to the embodiment. For example, the arrangement of the hot wire part, the number of the filaments constituting the hot wire part, the arrangement of each filament, the shape of each filament, the number of fine wire parts, the number of power feeding parts, etc. may be appropriately selected according to the embodiment. .

  If an example is given, each heat ray part (21, 22) should just be formed so that it may have a predetermined pattern so that the predetermined area | region of the glass plate 10 may be heated, and arrangement | positioning of each heat ray part (21, 22) The region to be set can be appropriately selected according to the embodiment. In addition, the conductive line portion 2 may be formed on the surface of the glass plate 10 on the vehicle outer side.

  Moreover, as illustrated in FIG. 4, the number of thin line portions extending from each base portion (230, 240, 250) may be appropriately selected according to the embodiment. FIG. 4 illustrates a conductive filament portion 5 according to another embodiment. The conductive wire portion 5 illustrated in FIG. 4 includes two heat wire portions (51, 52) and three power feeding portions 53 to 55.

  The power feeding portion 53 that is a positive electrode includes a base portion 530 and one thin wire portion 531 having a narrower line width than the base portion 530. Similarly, the power feeding unit 55 that is a positive electrode includes a base 550 and one thin line portion 551 having a line width narrower than that of the base 550. On the other hand, the power feeding unit 54 that is a negative electrode has a base 540 and two thin wire portions (541, 542) each having a narrower line width than the base 540.

  On the other hand, the three filaments 511 to 513 of the hot wire portion 51 extend from the vicinity of the upper end of the thin wire portion 531 of the power feeding portion 53, fold back, and return to the vicinity of the upper end of the thin wire portion 541 on the right side of the power feeding portion 54. ing. Further, of the four filaments 521 to 524 of the hot wire part 52, the two filaments (521, 522) arranged on the outside extend from the middle of the thin wire part 551 of the power feeding part 55, bend back, It returns to the vicinity of the upper end of the thin line portion 542 on the left side of the power feeding portion 54. On the other hand, the two filaments (523, 524) arranged on the inner side are repeatedly folded in the same manner as the respective heat wire portions (211, 212), and finally the thin wire portion 542 on the left side of the power feeding unit 54. It is back near the top of

  The number of filaments in such a hot wire part and the correspondence between the fine wire part and the hot wire part (strip) can be appropriately selected according to the embodiment. Further, the correspondence relationship between the positive electrode and the negative electrode of the power feeding unit may be reversed.

  Further, as illustrated in FIG. 5, the number of power feeding units is not limited to three, and the number of heat ray units is not limited to two. It can be appropriately selected depending on the form. FIG. 5 illustrates a conductive line portion 6 according to another embodiment. The conductive wire portion 6 illustrated in FIG. 5 includes one heat wire portion 61 and two power feeding portions (62, 63).

  The power feeding unit 62 that is a positive electrode includes a base 620 and two thin wire portions (621, 622) having a line width narrower than that of the base 620. Note that the fine line portion 622 arranged on the inner side has a larger line width than the fine line portion 621 arranged on the outer side.

  The power feeding unit 63 that is a negative electrode includes a base 630 and two thin wire portions (631 and 632) having a line width narrower than that of the base 630. Similarly to the power feeding unit 62, also in the power feeding unit 63, the fine line portion 631 arranged on the inner side is thicker than the thin line portion 632 arranged on the outer side. The line width of such a thin line portion can be changed as appropriate.

  On the other hand, the hot wire part 61 has the five filaments 611-615. Of these, the two filaments (611, 612) are connected to the fine wire portion 621 and the fine wire portion 632 having a narrower line width. On the other hand, the three filaments 613 to 615 are connected to the fine line portion 622 and the fine line portion 631 having a larger line width. Thus, you may change the line | wire width of a thin wire | line part according to the number of the filaments of a heat ray | wire part.

  Further, the line width of the thin wire portion of the power feeding portion may be the same as the line width of the heat ray portion. In other words, the thin wire portion of the power feeding portion may have a shape integrated with the filament of the heat wire portion.

  Furthermore, in the said embodiment, the heat ray part 21 and the heat ray part 22 are extended from the lower end part 12 side of the glass plate 10. FIG. Moreover, the heat ray part 21 and the heat ray part 22 are formed with the same material. However, the arrangement and material of the heat ray portion may be appropriately selected according to the embodiment. For example, you may comprise a heat ray | wire part so that it may illustrate in FIG.

  Drawing 6 illustrates window glass 1A provided with heat ray part 71 concerning other forms. In this window glass 1A, the glass plate 10 is formed in a trapezoidal shape. And this window glass 1A is equipped with the heat ray part 71 and the two electric power feeding parts (72, 73) for supplying electricity to this heat ray part 71, and comprises what is called a wire-heated windshield.

  Specifically, the heat ray portion 71 connects the bus bar portion 711 extending along the upper end portion 11 and the left end portion 14, the bus bar portion 712 extending along the lower end portion 12, and the bus bar portions (711, 712). The line 713 is provided. Here, each bus-bar part (711,712) may be formed with a copper film tape. On the other hand, each filament 713 may be formed of a conductive metal wire or the like. For example, a tungsten wire can be used for each filament 713. Thus, the material of each part of the heat ray part 71 can be suitably selected according to embodiment.

  Each power feeding section (72, 73) has a base section (721, 731) disposed so as to be in contact with the lower end section 12 and a thin wire section (722, 732) extending from each base section (721, 731). doing. The thin wire portion 722 of the power supply portion 72 is connected to the bus bar portion 712 of the heat wire portion 71, and the thin wire portion 732 of the power supply portion 73 is connected to the bus bar portion 711 of the heat wire portion 71. And the wiring from the power supply from a motor vehicle is connected with each electric power feeding part (72, 73). Thereby, electricity can be supplied to the heat ray part 71 via each electric power feeding part (72, 73). Note that, as in this modified example, the bus bar portion may be handled as one region of the heat ray portion. Moreover, when the wiring from a motor vehicle is connected to a bus-bar part, a bus-bar part may be handled as one area | region of an electric power feeding part.

  Moreover, in the said embodiment, each base (230,240,250) is arrange | positioned in the lower end part 12 vicinity of the glass plate 10, and each thin wire | line part (231,241-244,251-253) is each base (230,240). , 250) on the inner side of the glass plate 10 in the plane direction. However, the positional relationship between each base portion and each thin line portion may not be limited to such an example, and may be set as appropriate according to the embodiment. That is, in each power feeding unit, the region to be thinned may be appropriately set according to the embodiment.

(Molding equipment)
For example, in the above embodiment, the molding apparatus 902 that press-molds the glass plate 10 has been described. However, the method of forming the glass plate 10 of the window glass 1 is not limited to such an example, and may be formed by, for example, a self-weight bending method in which the glass plate 10 is bent by its own weight. In the self-weight bending method, the molding apparatus has, for example, a ring-shaped (frame-shaped) mold. The molding die is disposed on the transport table, and the flat glass plate 10 is placed on the molding die. In this state, the conveyance table sequentially passes through the heating furnace and the slow cooling furnace. Since the shaping | molding die is ring shape at this time, the glass plate 10 passes a heating furnace in the state in which only the peripheral part was supported. And if it heats to softening point temperature vicinity in a heating furnace, the inner side will curve below the peripheral part by dead weight, and the glass plate 10 will be shape | molded in a curved surface shape.

  Examples of the present invention will be described below. However, the present invention is not limited to this embodiment.

<1>
First, in order to verify how much the thermal stress acting near the region where the power supply unit is provided at the end of the glass plate increases when the power supply unit arranged at the end of the glass plate is lengthened, the following Such a simulation was performed. That is, the window glass which has the structure substantially the same as the said embodiment except the shape of the electric power feeding part was assumed as the window glass which concerns on a reference example. In the reference example, the three power feeding units are not subdivided and have a simple rectangular shape. The glass plate in this reference example was a laminated glass in which an interlayer film of 0.76 mm was disposed between an outer glass plate having a thickness of 2.0 mm and an inner glass plate having a thickness of 1.8 mm. Moreover, the conductive material which forms a conductive filament part was made into the silver paste. The pattern of the hot wire part is as shown in FIG. 1, the line width of each filament (211, 212, 221 to 223) is 1.0 mm to 2.0 mm, and the line width of each filament (224, 225) is 3 It was set to 0.0 mm to 7.0 mm. The heating value in each filament is 2000 W / m ² , the total resistance value of the entire circuit is 1.16 Ω to 1.56 Ω, and the sheet resistance value of each hot wire portion is 5.0 mΩ / sqr to 7.0 mΩ / sqr. did. Furthermore, the heat ray part shall be 40 mm away from the lower end part of the glass plate in the vicinity of the power supply part, and each power supply part was not provided with the base part and the fine wire part, and was assumed to be rectangular. In addition, the length of each electric power feeding part was 50 mm, 80 mm, and 42 mm. In addition, the width of each power feeding unit was set to 20 mm in common.

  On the other hand, a comparative example of a window glass having the same configuration as this reference example, in which the heat ray portion is further 40 mm away from the lower end of the glass plate in the vicinity of the feeding portion, and the length of each feeding portion is 88 mm, 110 mm, and 75 mm. It was. That is, in the comparative example, the heat ray part was assumed to be 85 mm away from the lower end part of the glass plate in the vicinity of the power feeding part. In the window glass according to the reference example and the comparative example, the heat generation of the conductive filament portion is performed under the conditions of the atmospheric temperature of 20 to 25 ° C., the energization voltage of 12 V, and the energization time of 25 minutes or more (when the current is stable). And the analysis software (Abaqus) capable of calculating the thermal stress in the glass plate, the temperature change and the thermal stress change generated in the window glass according to the reference example and the comparative example were simulated. The results are shown in FIGS.

  FIG. 7 shows a temperature distribution (simulation result) in the vicinity of the feeding portion of the window glass in the reference example. FIG. 8 shows a thermal stress distribution (simulation result) in the vicinity of the feeding portion of the window glass according to the reference example. On the other hand, FIG. 9 shows a temperature distribution (simulation result) in the vicinity of the feeding portion of the window glass in the comparative example. FIG. 10 shows a thermal stress distribution (simulation result) in the vicinity of the feeding portion of the window glass according to the comparative example.

  In the reference example, the thermal stress in the region where the power feeding unit is provided at the lower end of the glass plate (hereinafter, also referred to as “the root of the power feeding unit”), that is, the portion indicated by the arrow P1 in FIG. On the other hand, in the comparative example, the thermal stress in the portion indicated by the arrow P2 in FIG. 10 is 18 MPa, and it was found that the thermal stress generated in this portion becomes very large when the power feeding portion is lengthened.

  The cause of this was estimated as follows. That is, as can be seen from a comparison between the arrow H1 in FIG. 7 and the arrow H2 in FIG. 9, the region where the temperature is high is widened in the region where the power supply unit is arranged by increasing the power supply unit. Then, as indicated by the arrow C1 in FIG. 8 and the arrow C2 in FIG. 10, the region where the stress acts in the compression direction becomes wide. In the window glass according to the comparative example, a large thermal stress (tensile) acts on the root of the power feeding portion (the portion indicated by the arrow P2) in order to balance the stress in the region where the stress acts in the compression direction. It was estimated that

  Here, from the comparison between the reference example and the comparative example, the region in which the stress acts in the compression direction is also widened in correspondence with the wide temperature region. Therefore, by narrowing the high temperature region, that is, by lowering the temperature of the region where the power feeding unit is provided, the region where the stress acts in the compression direction is also narrowed, and the thermal stress acting on the root of the power feeding unit is also reduced. It was estimated. Accordingly, the present inventor has come up with the present invention in which the front end side of the power feeding portion is partially narrowed.

<2>
Next, in order to verify how much the thermal stress generated in the glass plate can be reduced by subdividing the power feeding portion, the following simulation was performed. That is, the window glass which has the same electric power feeding part as the said embodiment was assumed as the window glass which concerns on an Example. The width of each base was 20 mm and the length was 20 mm. Moreover, the length of the thin wire | line part corresponding to the thin wire | line part 231 was 65 mm, and the line width was 8 mm. The lengths of the thin wire portions corresponding to the thin wire portions 241 to 243 were 56 mm, 62 mm, and 55 mm, respectively, and the line width was 3 mm in common. The length of the fine wire portion corresponding to the fine wire portion 244 was 70 mm, and the line width was 8 mm. The length of the fine wire portion corresponding to the fine wire portion 251 was 40 mm, and the line width was 8 mm. The lengths of the thin wire portions corresponding to the thin wire portions (252 and 253) were 46 mm and 51 mm, respectively, and the line width was 3 mm in common. And the other conditions of the window glass which concerns on an Example were made the same as a comparative example. That is, the arrangement of the heat ray portions in the examples was the same as that in the comparative example.

  In the window glass in such an example, the temperature change and the thermal stress change generated in the window glass according to the example were simulated using the analysis software (Abaqus) under the same conditions as described above. The results are shown in FIGS. FIG. 11 shows a temperature distribution (simulation result) in the vicinity of the feeding portion of the window glass in the example. Moreover, Z11 shows the thermal stress distribution (simulation result) near the electric power feeding part of the window glass in an Example.

  Referring to FIGS. 9 and 11, the temperature of the region where the power feeding unit is provided is slightly lowered in the example as compared with the comparative example. Accordingly, the region where the stress acts in the compression direction indicated by the arrow C3 is also narrowed, and the thermal stress acting on the portion indicated by the arrow P3 is also reduced to 14.5 MPa. Therefore, it was shown that the thermal stress acting on the base of the power feeding part can be sufficiently reduced by subdividing the power feeding part.

1 ... Window glass
DESCRIPTION OF SYMBOLS 10 ... Glass plate, 11 ... Upper end part, 12 ... Lower end part, 13 ... Right side edge part, 14 ... Left side edge part,
2 ... Conductive filament part,
21 ... heat wire part, 211 ... strip, 212 ... strip,
22 ... hot wire part, 221-225 ... filament,
23 ... Power feeding unit, 230 ... Base, 231 ... Narrow wire part,
24 ... power feeding unit, 240 ... base, 241 to 244 ... thin wire portion,
25 ... Power feeding unit, 250 ... Base, 251-253 ... Narrow wire part,
3 ... shielding layer,
4 ... Harness,
5 ... Conductive filament part,
51 ... hot wire part, 511-513 ... filament,
52 ... hot wire part, 521-524 ... filament,
53 ... Power feeding part, 530 ... Base part, 531 ... Narrow wire part,
54 ... Power feeding part, 540 ... Base part, 541 and 542 ... Narrow wire part,
55 ... power feeding unit, 550 ... base, 551 ... thin wire portion,
6 ... Conductive filaments,
61 ... hot wire part, 611-615 ... filament,
62 ... Power feeding unit, 620 ... Base, 621 and 622 ... Fine wire part,
63 ... Power feeding unit, 630 ... Base, 631 and 632 ... Fine wire part,
71 ... Heat wire part, 711, 712 ... Bus bar part, 713 ... Line,
72 ... Power feeding unit, 721 ... Base, 722 ... Fine wire part,
73 ... Power feeding part, 731 ... Base part, 732 ... Narrow wire part,
901 ... Heating furnace, 902 ... Molding device, 921 ... Upper mold, 922 ... Lower mold,
903 ... Roller conveyor, 931 ... Roller

Claims (8)

A window glass for a vehicle that is formed of a glass plate and a conductive material and includes a conductive line portion disposed on any surface of the glass plate,
The conductive filament is
A hot wire portion that is disposed away from an end of the glass plate and has a predetermined pattern so as to heat a predetermined region of the glass plate;
A power feeding unit that extends from the vicinity of the end of the glass plate and is connected to the hot wire part, and feeds power to the hot wire part,
With
The power feeding part is partially thinned,
Window glass. The power feeding unit includes a base disposed in the vicinity of the end of the glass plate, and a thin line portion having a line width narrower than the base and extending from the base.
The window glass according to claim 1. A plurality of the thin wire portions are provided,
The plurality of thin line portions are separated from each other,
The hot wire portion is fed by being connected to any of the plurality of thin wire portions,
The window glass according to claim 2. The heat ray part is divided and connected to each of the plurality of fine line parts.
The window glass according to claim 3. The distance separating the plurality of thin wire portions from each other is configured to be longer than the line width of each of the plurality of thin wire portions.
The window glass according to claim 3 or 4. The base of the power feeding unit is disposed so as to contact the end of the glass plate.
The window glass of any one of Claim 2 to 5. The conductive material includes silver;
The window glass of any one of Claim 1 to 6. The window glass is used as a windshield for automobiles,
The window glass of any one of Claim 1 to 7.