JP6938366B2 - Windshield - Google Patents

Description

The present invention relates to a windshield and a method for producing the same.

The windshield in which the head-up display device is used is generally formed in a wedge shape in order to prevent a double image. As described above, there are various methods for forming the windshield into a wedge shape. For example, in Patent Document 1, the thickness of the interlayer film and the inner glass plate is made constant, and the outer glass plate is formed into a wedge shape. Is disclosed.

JP-A-2017-105665

By the way, as described above, when at least one of the outer glass plate and the inner glass plate is wedge-shaped, the shape of the end face becomes a problem. Generally, the end faces of the outer glass plate and the inner glass plate are polished in an arc shape, but the contact position with the interlayer film differs between the outer glass plate and the inner glass plate depending on the shape of the polished arc. There is a problem that it becomes unattractive and looks bad. Such a problem cannot occur when both glass plates are flat plates. The present invention has been made to solve this problem, and provides a windshield and a method for manufacturing the same, which can improve the appearance of the end face when at least one of the two glass plates is wedge-shaped. The purpose is.

Item 1. A first glass plate having a first surface and a second surface and a first surface and a second surface are arranged so that the first surface and the second surface of the first glass plate face each other. 2 glass plates and
An interlayer film sandwiched between the first glass plate and the second glass plate,
With
The first glass plate has a first end portion and a second end portion facing the first end portion, and is formed so that the thickness decreases from the first end portion to the second end portion.
The end face connecting the first surface and the second surface of the first glass plate is formed in an arc shape in cross section.
The end face connecting the first surface and the second surface of the second glass plate is formed in an arc shape in cross section.
A windshield configured such that an edge on the second surface side of the end surface of the first glass plate and an edge on the first surface side of the end surface of the second glass plate face each other.

Item 2. The second glass plate has a first end portion and a second end portion corresponding to the first end portion and the second end portion of the first glass plate.
Item 2. The windshield according to Item 1, wherein the second glass plate is formed so that the thickness decreases from the first end portion to the second end portion.

Item 3. The first glass plate and the second glass plate have different concentrations of tin oxide on the first surface and the second surface, respectively.
Item 1 or 2, wherein the first glass plate and the second glass plate are arranged such that the surfaces having a high tin oxide concentration or the surfaces having a low tin oxide concentration face each other. Windshield.

Item 4. Item 3. The windshield according to Item 3, wherein the first glass plate and the second glass plate are arranged so that the surfaces having a high concentration of tin oxide face each other.

Item 5. Item 2. The windshield according to Item 1, wherein the second glass plate is formed of a flat plate having a substantially constant thickness.

Item 6. The first glass plate and the second glass plate have different concentrations of tin oxide on the first surface and the second surface, respectively.
The surface of the first glass plate having a low concentration of tin oxide and the surface of the second glass plate having a low concentration of tin oxide are arranged so as to face each other.
Item 5. The windshield according to Item 5, wherein at least one of a shielding layer and an antenna is laminated on the second surface of the second glass plate.

Item 7. The first glass plate has streaks formed on it.
Item 2. The windshield according to any one of Items 1 to 6, wherein the second glass plate is formed with streaks orthogonal to the streaks of the first glass plate.

Item 8. At the first end portion, the angle formed by the tangent line passing through the boundary between the second surface and the end surface of the first glass plate and in contact with the end surface and the second surface is θ1,
At the second end, the angle formed by the tangent line that passes through the boundary between the second surface and the end surface of the first glass plate and is in contact with the end surface and the second surface is θ2.
When stipulated
Item 4. The windshield according to any one of Items 1 to 7, which satisfies θ1 = θ2.

Item 9. It has a first surface and a second surface, and also has a first end portion and a second end portion facing the first end portion, so that the thickness decreases from the first end portion to the second end portion. Steps to prepare the first glass plate formed in
A step of preparing a second glass plate having a first surface and a second surface,
A step of preparing a grindstone that is a cylindrical grindstone rotatably supported around an axis and in which the cross-sectional shape of the outer peripheral surface in the axial direction is formed in an arc shape that is convex inward in the radial direction.
In the first glass plate, a step of polishing an end surface connecting the first surface and the second surface, in which the second surface and the end surface are arranged so as to be orthogonal to each other, and the grindstone is rotated. A step of arranging the grindstone so that the shaft and the end face are parallel to each other, and then polishing the end face in an arc shape over the entire circumference by the grindstone.
In the second glass plate, a step of polishing an end surface connecting the first surface and the second surface, in which the first surface and the end surface are arranged so as to be orthogonal to each other, and the grindstone is rotated. A step of arranging the grindstone so that the shaft and the end face are parallel to each other, and then polishing the end face in an arc shape over the entire circumference by the grindstone.
A step of arranging an interlayer film between the second surface of the first glass plate and the first surface of the second glass plate and applying pressure to integrate them.
How to make a windshield.

According to the present invention, even if at least one of the two glass plates is wedge-shaped, the appearance of the end face can be improved.

It is a front view which shows one Embodiment of the windshield which concerns on this invention. FIG. 1 is a cross-sectional view taken along the line AA of FIG. It is sectional drawing near the end face of the windshield of FIG. It is a figure explaining an example of the manufacturing method of a float glass plate. It is sectional drawing explaining the method of cutting out a glass plate. It is sectional drawing of the float glass plate. It is sectional drawing of the windshield of FIG. It is a front view explaining the line of the windshield of FIG. It is a figure which shows the polishing of a glass plate. It is a figure which shows the polishing of a glass plate. It is sectional drawing of the glass plate after polishing. It is a top view of the molding mold of a glass plate. It is a side view of the furnace through which the molding die of FIG. 12 passes. It is the schematic of the head-up display device. It is sectional drawing which shows the vicinity of the end face of the windshield which contrasts with this invention. It is sectional drawing near the end face of another windshield of this invention. It is sectional drawing near the end face of another windshield of this invention. It is sectional drawing near the end face of another windshield of this invention. It is sectional drawing near the end face of another windshield of this invention.

<1. Overview of Windshield>
Hereinafter, an embodiment of an automobile windshield according to the present invention will be described with reference to the drawings. The windshield according to the present embodiment is used for displaying information by projecting the emitted light by the head-up display device.

FIG. 1 is a front view of the windshield according to the present embodiment, and FIG. 2 is a cross-sectional view taken along the line AA of FIG. As shown in FIGS. 1 and 2, the windshield according to the present embodiment includes an outer glass plate 1, an inner glass plate 2, and an interlayer film 3 arranged between the glass plates 1 and 2. ing. A shielding layer 4 is laminated on this windshield. Hereinafter, each member will be described.

<2. Outer glass plate and inner glass plate>
First, the outer glass plate 1 and the inner glass plate 2 will be described. As the outer glass plate 1 and the inner glass plate 2, known glass plates can be used, and the outer glass plate 1 and the inner glass plate 2 can be formed of heat ray absorbing glass, general clear glass or green glass, or UV green glass. However, these glass plates 1 and 2 need to realize visible light transmittance in accordance with the safety standards of the country in which the automobile is used. For example, the outer glass plate 1 can secure the required solar radiation absorption rate, and the inner glass plate 2 can adjust the visible light transmittance so as to satisfy the safety standard. An example of clear glass, heat ray absorbing glass, and soda lime glass is shown below.

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

(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 the amount of increase in 2 and TiO _2.

(Soda lime glass)
SiO ₂ : 65-80% by mass
Al ₂ O ₃ : 0-5% by mass
CaO: 5 to 15% by mass
MgO: 2% by mass or more NaO: 10 to 18% by mass
K ₂ O: 0 to 5% by mass
MgO + CaO: 5 to 15% by mass
Na ₂ O + K ₂ O: 10 to 20% by mass
SO ₃ : 0.05 to 0.3% by mass
B ₂ O ₃ : 0 to 5% by mass
Total iron oxide converted to Fe ₂ O _{3 (T-Fe 2} O ₃ ): 0.02 to 0.03% by mass

The outer glass plate 1 is formed in a trapezoidal shape and has an upper side (first end portion) 11, a lower side (second end portion) 12, a right side side 13, and a left side side 14. Further, the outer glass plate has a first surface 101 facing the outside of the vehicle and a second surface 102 facing the inside of the vehicle, and has an end surface connecting the first surface and the second surface. Further, the outer glass plate 1 is formed in a wedge shape so that the thickness decreases from the upper side 11 to the lower side 12. Similarly, the inner glass plate 2 is also formed in a trapezoidal shape, and has an upper side 21, a lower side 22, a right side 23, and a left side 24. Further, the inner glass plate also has a first surface 201 facing the outside of the vehicle and a second surface 202 facing the inside of the vehicle, and has an end surface connecting the first surface 201 and the second surface 202. However, unlike the outer glass plate 1, the inner glass plate 2 is formed of a flat plate having a constant thickness.

Then, the above-mentioned interlayer film 3 is arranged between the second surface 102 of the outer glass plate 1 and the first surface 201 of the inner glass plate 2.

Next, the shapes of the end faces of the outer glass plate 1 and the inner glass plate 2 will be described with reference to FIG. As shown in FIG. 3, the end surface 15 of the outer glass plate 1 is polished so that the cross section has an arc shape. On the other hand, the inner glass plate 2 is polished so that the end face 25 thereof has an arcuate cross section, similarly to the outer glass plate 1.

Further, the edge S11 on the second surface 102 side of the end surface of the outer glass plate and the edge S21 on the first surface 201 side of the end surface 25 of the inner glass plate 2 face each other. That is, these edge edges S11 and S21 are formed so that the distance X from the outermost end surface 25 of the inner glass plate 2 is the same in the surface direction of the inner glass plate 2.

The thickness of the windshield according to the present embodiment is not particularly limited, but from the viewpoint of weight reduction, the total thickness of the outer glass plate 1 and the inner glass plate 2 is preferably 2.4 to 5.0 mm. It is more preferably 2.6 to 4.6 mm, and particularly preferably 2.7 to 3.2 mm. As described above, in order to reduce the weight, it is necessary to reduce the total thickness of the outer glass plate 1 and the inner glass plate 2, so that the respective thicknesses of the glass plates 1 and 2 are particularly limited. However, for example, the thicknesses of the outer glass plate 1 and the inner glass plate 2 can be determined as follows. The thickness of the glass plates 1 and 2 can be measured with a micrometer.

The outer glass plate 1 is mainly required to have durability against external obstacles and impact resistance, and is required to have impact resistance against flying objects such as pebbles. On the other hand, the larger the thickness, the heavier the weight, which is not preferable. From this viewpoint, the thickness of the outer glass plate 1 is preferably 1.8 to 2.3 mm, more preferably 1.9 to 2.1 mm. Which thickness to use can be determined according to the application of the glass. However, since the upper side 11 is thicker than the lower side 12, for example, the thickness of the upper side 11 is 2.5 to 5.0 mm, the thickness of the lower side 12 is 2.6 to 6.7 mm, and the thickness of the upper side 11 and the lower side 12 is increased. The difference can be 0.1 to 1.7 mm.

The thickness of the inner glass plate 2 can be made equal to that of the outer glass plate 1, but for example, the thickness can be made smaller than that of the outer glass plate 1 in order to reduce the weight of the windshield. Specifically, considering the strength of the glass, it is preferably 0.6 to 2.3 mm, preferably 0.8 to 2.0 mm, and particularly 1.0 to 1.4 mm. preferable. Further, it is preferably 0.8 to 1.3 mm. As for the inner glass plate 2, which thickness should be adopted can be determined according to the use of the glass.

Further, the shapes of the outer glass plate 1 and the inner glass plate 2 according to the present embodiment are curved shapes. When the windshield has a curved shape, it is said that the sound insulation performance deteriorates as the amount of doubling increases. The amount of doubling is an amount indicating the bending of the windshield. For example, when a straight line connecting the center of the upper side and the center of the lower side of the windshield is set, the largest distance between this straight line and the windshield is set. Defined as the amount of duplication.

Here, an example of a method for measuring the thickness of the windshield 1 will be described. First, the measurement positions are two points above and below the center line extending vertically along the center of the windshield in the left-right direction. The measuring device is not particularly limited, but for example, a thickness gauge such as SM-112 manufactured by TECLOCK Co., Ltd. can be used. At the time of measurement, the curved surface of the windshield is placed on a flat surface, and the end of the windshield is sandwiched between the thickness gauges for measurement.

<3. Manufacturing method of outer glass plate and inner glass plate>
Next, an example of a method for manufacturing the outer glass plate 1 and the inner glass plate 2 will be described with reference to FIG. As an example, the outer glass plate 1 and the inner glass plate 2 can be a float glass plate manufactured by the float method.

FIG. 4 is a diagram showing a method of manufacturing a float glass plate. In FIG. 4, the vertical direction of the paper surface is the flow direction of the molten glass 55, and the left-right direction is the width direction of the molten glass 55. In FIG. 4, the change in the thickness of the molten glass 55 is exaggerated.

In the float method, the molten glass 55 is continuously supplied on the molten metal 54 such as molten tin, and the supplied molten glass 55 is made to flow on the molten metal 54 to form a strip. The glass thus formed is referred to as a glass ribbon 55.

Then, in order to suppress the shrinkage of the glass ribbon 55 in the width direction, both ends of the glass ribbon 55 in the width direction are pressed by a pair of rollers 56, respectively. A plurality of these pair of rollers 56 are provided at intervals in the flow direction of the glass ribbon 55. The rotation of the plurality of pairs of rollers 16 causes the glass ribbon 55 to move to the downstream side.

The glass ribbon 55 is cooled toward the downstream side, cooled and solidified, and then pulled up from the molten metal 54. Then, after being slowly cooled, it is cut. In this way, a float glass plate is obtained. Here, in the float glass plate, the surface in contact with the molten metal 54 is referred to as a bottom surface, and the surface opposite to the bottom surface is referred to as a top surface. The bottom surface and the top surface may be unpolished. Since the bottom surface was in contact with the molten metal 54, when the molten metal 54 was tin, the concentration of tin oxide contained in the bottom surface was higher than the concentration of tin oxide contained in the top surface. Become.

In FIG. 4, the pair of rollers 56 pulls the glass ribbon 55 in the width direction, so that the thickness of the glass ribbon 55 increases from both ends in the width direction toward the center. When the glass ribbon 55 thus formed is solidified and then cut, the outer glass plate 1 is obtained. At this time, there are two ways to cut out the outer glass plate, as shown in FIG. First, as shown on the right side of FIG. 5, the glass ribbon 55 is cut so that the cut surfaces K1 and K2 extend in the vertical direction. These cut surfaces K1 and K2 extend in parallel, and in the outer glass plate 1A thus obtained, the cut surfaces K1 and K2 and the bottom surface are orthogonal to each other. In another method, as shown on the left side of FIG. 5, the glass ribbon 55 is cut so that the cut surfaces K3 and K4 perpendicular to the top surface are formed. These cut surfaces K3 and K4 extend in parallel, and in the outer glass plate 1B thus obtained, the cut surfaces K3 and K4 and the top surface are orthogonal to each other. Which cutting method is adopted depends on the performance required for the wind seed obtained as described later. In any case, the outer glass plate 1 is cut out so that the thickness of the upper side 11 is large and the thickness of the lower side 12 is small.

On the other hand, the inner glass plate 2 is also formed by the float method like the outer glass plate 1, but is formed by a known method that does not use the rollers described above. Therefore, the thickness of the inner glass plate 2 is formed to be substantially constant.

Further, since the glass ribbon 55 flows on the molten metal 54, a plurality of streaks extending in the flow direction are formed on the surface thereof. Then, this streak is also formed on the surface of the cooled float glass plate. Then, as shown in FIG. 6, wavy irregularities are formed on the surface of the inner glass plate 2 by the streaks in the direction of the streaks. Note that FIG. 6 has the same cross section as that of FIG. 4, and shows a cross section orthogonal to the flow direction of the glass plate. Similar irregularities are also formed on the outer glass plate 1. However, in each of the glass plates 1 and 2, the unevenness of the bottom surface that was in contact with the molten metal 54 is smaller than the unevenness of the top surface. Here, the term "small unevenness" means that the difference between the deepest part and the uppermost part of the unevenness is small. Further, on the surface of the glass plate formed by the float method, in addition to the above-mentioned streaks, swells extending in a direction orthogonal to the streaks are also formed. This swell has a pitch larger than the pitch of the streaks, and the size is smaller than the unevenness of the streaks.

Then, in the windshield according to the present embodiment, as shown in FIG. 7, both the second surface 102 of the outer glass plate 1 and the first surface 201 of the inner glass plate 2 are the top surfaces. As a result, the unevenness of the first surface 101 of the outer glass plate 1, the second surface 202 of the inner glass plate 2, that is, the surface facing the outside of the windshield is reduced.

Further, in the present embodiment, as shown in FIG. 8, the streaks of the outer glass plate 1 and the streaks of the inner glass plate 2 are orthogonal to each other. That is, the streaks 150 of the outer glass plate 1 extend in parallel with the upper side 11 and the lower side 12 by the method described above. On the other hand, since the inner glass plate 2 has a constant thickness, the direction of the streaks can be adjusted. Therefore, the inner glass plate 2 is cut out from the glass ribbon so that the streaks 250 extend from the upper side 21 to the lower side 22. In this way, the windshield is formed so that the streaks 150 of the outer glass plate 1 and the streaks 250 of the inner glass plate 2 are orthogonal to each other.

In the production of the outer glass plate 1, if the molding conditions are adjusted, the thickness is increased from both ends in the width direction toward the center, or from one end to the other end in the width direction. It can also be made thicker. The thickness of the glass ribbon 55 can be adjusted by the tension of the roller 56, the peripheral speed of the roller 56, and the like.

Next, polishing of the end faces of the outer glass plate 1 and the inner glass plate 2 will be described. The end faces of the glass plates 1 and 2 are formed by polishing with a grindstone. First, as shown in FIG. 5, the outer glass plate 1 is cut out from the glass ribbon 55 so that the second surface 102 and the end surface 15 are orthogonal to each other. Then, the grindstone 7 is brought into contact with the outer glass plate 1 to polish the end face. The grindstone 7 is formed in a cylindrical shape and is rotatably supported around its axis 71. Further, the cross section of the outer peripheral surface 72 of the grindstone 7 in the axial direction is formed in an arc shape that is convex inward in the radial direction. That is, the grindstone 7 is formed so that the diameters at both ends in the axial direction are large and the diameter near the center in the axial direction is the smallest.

Then, the outer glass plate 1 is supported so that the second surface 102 is horizontal, and while rotating the grindstone 7, the grindstone 7 is spread over the entire circumference of the end surface 15 of the outer glass plate 1 as shown in FIG. To move. At this time, the height of the grindstone 7 in the vertical direction is constant. Further, the depth of cut Z of the grindstone 7 is the same over the entire circumference of the outer glass plate. Here, the depth of cut Z is a distance obtained by moving the grindstone from the position where the edge of the second surface 102 of the outer glass plate 1 comes into contact with the grindstone in the surface direction of the second surface 102 for polishing.

In this way, the end surface 15 of the outer glass plate 1 is polished in an arc shape. At this time, the outer glass plate 1 is supported so that the second surface 102 extends horizontally, but the first surface 101 is supported so as to incline downward from the upper side 11 to the lower side 12. As shown in FIG. 11, the angle formed by the end surface 15 and the first surface 101 and the second surface 102 is formed as follows.

Here, it is defined as follows.
At the upper side 11, the angle formed by the tangent line Z1 passing through the boundary S11 between the second surface 102 and the end surface 15 and tangent to the end surface 15 and the second surface 102 is θ1.
At the lower side 12, the angle formed by the tangent line Z2 passing through the boundary S12 between the second surface 102 and the end surface 15 and tangent to the end surface 15 and the second surface 102 is θ2.
At the upper side 11, the angle formed by the tangent line Z3 that passes through the boundary S13 between the first surface 101 and the end surface 15 and is in contact with the end surface 15 and the first surface 101 is θ3.
At the lower side 12, the angle formed by the tangent line Z4 that passes through the boundary S14 between the first surface 101 and the end surface 15 and is in contact with the end surface 15 and the first surface 101 is θ4.

At this time, of θ1 to θ4, θ1 and θ2 satisfy the following equation (1).
θ1 = θ2 (1)
This is because the position of the grindstone 7 in the axial direction with respect to the second surface 102 is fixed, and then the outer glass plate 1 is polished over the entire circumference. Further, as a result, the outermost ends of the end faces of both the glass plates 1 and 2 can be positioned at the same position in the plane direction.

Further, the end face of the inner glass plate 2 is also polished by the above-mentioned grindstone 7 in the same manner. That is, the end faces of the outer glass plate 1 and the inner glass plate 2 are polished by the grindstone 7 having the same radius of curvature. At this time, the cutting amount of the inner glass plate 2 by the grindstone 7 is the same as that of the outer glass plate 1. The depth of cut is a distance obtained by moving the grindstone 7 in the direction of the surface of the first surface 201 for polishing from the position where the end surface 25 of the first surface 201 of the inner glass plate 2 and the grindstone are in contact with each other. Further, the position of the grindstone 7 in the axial direction with respect to the thickness direction of the inner glass plate 2 is also adjusted. In this way, the outer glass plate 1 and the inner glass plate 2 adjust the axial position of the grindstone 7 while making the depth of cut of the grindstone 7 the same. Therefore, as described above, the outer glass plate 1 The edge S1 on the second surface 102 side of the end surface of the glass plate 2 and the edge S2 on the first surface 201 side of the end surface 25 of the inner glass plate 2 face each other.

<4. Intermediate membrane>
The interlayer film 3 has a substantially constant thickness and is formed of at least one layer. As an example, as shown in the enlarged view of FIG. 2, the soft core layer 31 can be composed of three layers sandwiched between outer layers 32 that are harder than this. However, the configuration is not limited to this, and it may be formed by a plurality of layers having a core layer 31 and at least one outer layer 32 arranged on the outer glass plate 1 side. For example, a two-layer interlayer film 3 including a core layer 31 and one outer layer 32 arranged on the outer glass plate 1 side, or an even number of outer layers 32 having two or more layers on both sides of the core layer 31 as a center. The arranged interlayer film 3 or the intermediate film 3 in which an odd number of outer layers 32 are arranged on one side and an even number of outer layers 32 are arranged on the other side of the core layer 31 may be used. When only one outer layer 32 is provided, it is provided on the outer glass plate 1 side as described above, in order to improve the damage resistance performance against external force from outside the vehicle or outdoors. Further, when the number of outer layers 32 is large, the sound insulation performance is also high.

As long as the core layer 31 is softer than the outer layer 32, its hardness is not particularly limited. The material constituting each of the layers 31 and 32 is not particularly limited, but for example, the outer layer 32 can be made of, for example, polyvinyl butyral resin (PVB). Polyvinyl butyral resin is preferable because it has excellent adhesiveness and penetration resistance to each glass plate. On the other hand, the core layer 31 can be made of, for example, ethylene vinyl acetate resin (EVA) or polyvinyl acetal resin which is softer than the polyvinyl butyral resin constituting the outer layer. By sandwiching the soft core layer between them, the sound insulation performance can be greatly improved while maintaining the same adhesiveness and penetration resistance as the single-layer resin interlayer film.

Generally, the hardness of a polyvinyl acetal resin is controlled by (a) the degree of polymerization of polyvinyl alcohol as a starting material, (b) the degree of acetalization, (c) the type of plasticizer, (d) the addition ratio of the plasticizer, and the like. Can be done. Therefore, by appropriately adjusting at least one selected from these conditions, even if the same polyvinyl butyral resin is used, the hard polyvinyl butyral resin used for the outer layer 32 and the soft polyvinyl butyral resin used for the core layer 31 are used. It is possible to make it separately from. Further, the hardness of the polyvinyl acetal resin can also be controlled by the type of aldehyde used for acetalization, co-acetalization with a plurality of types of aldehydes, or pure acetalization with a single type of aldehyde. Although it cannot be said unconditionally, the polyvinyl acetal resin obtained by using an aldehyde having a large number of carbon atoms tends to be softer. Therefore, for example, when the outer layer 32 is made of polyvinyl butyral resin, the core layer 31 has an aldehyde having 5 or more carbon atoms (for example, n-hexyl aldehyde, 2-ethylbutyl aldehyde, n-heptyl aldehyde, etc.). A polyvinyl acetal resin obtained by acetalizing n-octylaldehyde) with polyvinyl alcohol can be used. If a predetermined Young's modulus can be obtained, it is not limited to the above resins and the like.

The total thickness of the interlayer film 3 is not particularly specified, but is preferably 0.3 to 6.0 mm, more preferably 0.5 to 4.0 mm, and 0.6 to 2.0 mm. It is particularly preferable to have. The thickness of the core layer 31 is preferably 0.1 to 2.0 mm, more preferably 0.1 to 0.6 mm. On the other hand, the thickness of each outer layer 32 is preferably 0.1 to 2.0 mm, more preferably 0.1 to 1.0 mm. In addition, the total thickness of the interlayer film 3 can be kept constant, and the thickness of the core layer 31 can be adjusted.

The thicknesses of the core layer 31 and the outer layer 32 can be measured, for example, as follows. First, the cross section of the windshield is magnified 175 times and displayed by a microscope (for example, VH-5500 manufactured by KEYENCE CORPORATION). Then, the thicknesses of the core layer 31 and the outer layer 32 are visually specified and measured. At this time, in order to eliminate visual variations, the number of measurements is set to 5, and the average value is taken as the thickness of the core layer 31 and the outer layer 32.

The total thickness of the interlayer film 3 is not particularly specified, but is preferably 0.3 to 6.0 mm, more preferably 0.5 to 4.0 mm, and 0.6 to 2.0 mm. It is particularly preferable to have. The thickness of the core layer 31 is preferably 0.1 to 2.0 mm, more preferably 0.1 to 0.6 mm. On the other hand, the thickness of each outer layer 32 is preferably larger than the thickness of the core layer 31, specifically, preferably 0.1 to 2.0 mm, and preferably 0.1 to 1.0 mm. Is even more preferable. In addition, the total thickness of the interlayer film 3 can be kept constant, and the thickness of the core layer 31 can be adjusted.

The thicknesses of the core layer 31 and the outer layer 32 can be measured, for example, as follows. First, the cross section of the windshield is magnified 175 times and displayed by a microscope (for example, VH-5500 manufactured by KEYENCE CORPORATION). Then, the thicknesses of the core layer 31 and the outer layer 32 are visually specified and measured. At this time, in order to eliminate visual variations, the number of measurements is set to 5, and the average value is taken as the thickness of the core layer 31 and the outer layer 32. For example, an enlarged photograph of the windshield is taken, and the core layer and the outer layer 32 are identified and the thickness is measured.

The method for producing the interlayer film 3 is not particularly limited, but for example, a resin component such as the above-mentioned polyvinyl acetal resin, a plasticizer, and other additives as necessary are blended and kneaded uniformly, and then each layer is collectively kneaded. Examples thereof include a method of extrusion molding with the above method, and a method of laminating two or more resin films produced by this method by a pressing method, a laminating method, or the like. The resin film before lamination used in the laminating method by a pressing method, a laminating method, or the like may have a single-layer structure or a multi-layer structure. Further, the interlayer film 3 can be formed by one layer in addition to being formed by a plurality of layers as described above.

<5. Shielding layer>
As shown in FIG. 1, a shielding layer 2 is laminated on a dark ceramic such as black on the peripheral edge of the windshield. The shielding layer 4 shields the field of view from the inside or the outside of the vehicle, and is laminated along the four sides of the windshield.

＊１，主成分：酸化銅、酸化クロム、酸化鉄及び酸化マンガン
＊２，主成分：ホウケイ酸ビスマス、ホウケイ酸亜鉛 The shielding layer 4 can have various aspects such as, for example, only the inner surface of the outer glass plate 1, only the inner surface of the inner glass plate 2, or the inner surface of the outer glass plate 1 and the inner surface of the inner glass plate 2. Further, it can be formed of ceramic or various materials, and for example, it can have the following composition.

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

The ceramic can be formed by a screen printing method, but it can also be produced by transferring a baking transfer film to a glass plate and firing it. When screen printing is adopted, for example, polyester screen: 355 mesh, coat thickness: 20 μm, tension: 20 Nm, squeegee hardness: 80 degrees, mounting angle: 75 °, printing speed: 300 mm / s can be set, and a drying oven. The ceramic can be formed by drying at 150 ° C. for 10 minutes.

The ceramic easily adheres to the bottom surface of the glass ribbon 55 described above. This is because the concentration of tin oxide on the bottom surface is high. Therefore, when the shielding layer 4 is formed of ceramic, it is preferably formed in the bottom layer. Therefore, for example, when forming the windshield as shown in FIG. 7, the shielding layer 4 can be formed on the second surface 202 of the inner glass plate 2. The shielding layer 4 can be formed by laminating ceramics or by attaching a shielding film made of a dark resin.

<6. Windshield manufacturing method>
Next, a method of manufacturing the windshield will be described. First, the glass plate production line will be described.

Here, the molding mold will be described in more detail with reference to FIG. FIG. 12 is a plan view of the molding die. As shown in FIG. 12, the molding mold 800 includes a frame-shaped mold main body 810 that substantially matches the outer shape of both the glass plates 1 and 2. Since the mold body 810 is formed in a frame shape, it has an internal space 820 that penetrates in the vertical direction inside. Then, the peripheral edges of the flat glass plates 1 and 2 are placed on the upper surface of the mold body 810. Therefore, heat is applied to the glass plates 1 and 2 from a heater (not shown) arranged on the lower side through the internal space. As a result, both the glass plates 1 and 2 are softened by heating and are curved downward due to their own weight. A shielding plate 840 for shielding heat may be arranged on the inner peripheral edge of the mold body 810, whereby the heat received by the glass plates 1 and 2 can be adjusted. Further, the heater can be provided not only below the mold 800 but also above the mold 800.

Next, the molding method will be described with reference to FIG. FIG. 13 is a side view of the furnace through which the molding die passes. First, the above-mentioned shielding layer 2 is laminated on the outer glass plate 1 and the inner glass plate 2 before bending. Next, the outer glass plate 1 and the inner glass plate 2 are overlapped and passed through the heating furnace 802 as shown in FIG. 13 in a state of being supported by the molding mold 800. When heated to near the softening point temperature in the heating furnace 802, both glass plates 1 and 2 are curved downward from the peripheral edge due to their own weight, and are formed into a curved surface. Subsequently, both the glass plates 1 and 2 are carried into the slow cooling furnace 803 from the heating furnace 802, and the slow cooling treatment is performed. After that, both the glass plates 1 and 2 are carried out from the slow cooling furnace 803 and allowed to cool.

When the outer glass plate 1 and the inner glass plate 2 are formed in this way, the interlayer film 3 is subsequently sandwiched between the outer glass plate 1 and the inner glass plate 2. The interlayer film 3 has a shape slightly larger than that of the outer glass plate 1 and the inner glass plate 2. As a result, the outer edge of the intermediate layer 3 is in a state of protruding from the outer glass plate 1 and the inner glass plate 2.

Next, the laminate in which both the glass plates 1 and 2 and the interlayer film 3 are laminated is placed in a rubber bag and pre-bonded at about 70 to 110 ° C. while sucking under reduced pressure. The method of pre-adhesion can be other than this, and the following method can also be adopted. For example, the laminate is heated in an oven at 45-65 ° C. Next, the laminate is pressed with a roll at 0.45 to 0.55 MPa. Subsequently, the laminate is heated again in the oven at 80 to 105 ° C. and then pressed again with a roll at 0.45 to 0.55 MPa. In this way, the pre-adhesion is completed.

Next, the main bonding is performed. The pre-bonded laminate is main-bonded by an autoclave, for example, at 8 to 15 atm and at 100 to 150 ° C. Specifically, for example, the main bonding can be performed at 14 atm and 135 ° C. Through the above pre-adhesion and main adhesion, the interlayer film 3 is adhered to each of the glass plates 1 and 2. Finally, by cutting the interlayer film 3 protruding from the outer glass plate 1 and the inner glass plate 2, a windshield having a cross section as shown in FIG. 3 is manufactured. It should be noted that a curved windshield can also be manufactured by another method, for example, press working.

<7. Head-up display device>
Next, the head-up display device will be described. The head-up display device (referred to as a HUD device) projects information such as vehicle speed on the windshield. However, it is known that when this HUD device is used, a double image is formed by the light projected on the windshield. That is, since the image that is visually recognized by being reflected by the inner surface of the windshield and the image that is visually recognized by being reflected by the outer surface of the windshield are visually recognized separately, the image is duplicated.

In order to prevent this, a windshield having a wedge-shaped outer glass plate 1 as in the present embodiment is used. That is, as shown in FIG. 14, in the windshield, at least in the display region where the light is projected from the HUD device 500, the windshield is formed so as to become smaller as the thickness decreases. As a result, the light reflected by the inner surface of the windshield (second surface 202 of the inner glass plate 2) and incident on the inside of the vehicle is reflected by the outer surface of the windshield (first surface 101 of the outer glass plate 1) and then inside the vehicle. Since the light incident on the above is almost the same, the double image is eliminated. The wedge angle α of the windshield 1 at this time, that is, the angle formed by the first surface 101 and the second surface 101 of the outer glass plate 1 depends on the installation angle of the windshield 1, but is, for example, 0.01. It can be ~ 0.04 degrees (0.2 ~ 0.7 mrad).

<8. Features>
According to the windshield according to the present embodiment, the following effects can be obtained.
(1) As shown in FIG. 3, in the present embodiment, the end surface S11 on the second surface 102 side of the end surface 15 of the outer glass plate 1 and the second end surface 25 of the inner glass plate 2 formed in an arc shape. The edge S21 on the side 201 on one surface faces the edge S21. Therefore, when the interlayer film 3 is sandwiched between them, the position where the interlayer film 3 and the outer glass plate 1 are in contact (edge edge S11) and the position where the intermediate film 3 and the inner glass plate 2 are in contact with each other (edge edge S21). And can be in the same position from the end face of the windshield. This makes it look good. On the other hand, for example, as shown in FIG. 15, if the positions of the edge edges S11 and S21 are different, the appearance will be poor.

In particular, when the interlayer film 3 absorbs moisture and swells, if the positions of the edge S11 and S21 are different, the amount of swelling toward the outer glass plate 1 and the inner glass in the vicinity of the edge S11 and S21 The amount of swelling toward the plate 2 side will be different, and the appearance will be worse.

Further, since the axial position of the grindstone 7 with respect to the second surface 102 is fixed when the end surface 15 of the outer glass plate 1 is polished, the positions of the edge S11 and S12 of the end surface 15 on the second surface 102 side are set. It can be the same over the entire circumference of the outer glass plate 1. As a result, the edge S11 and S12 can be easily made to face the edge S21 of the end surface 25 on the first surface 201 side of the inner glass plate 2.

(2) In the above embodiment, the bottom surface having small irregularities due to the streaks is used as the outer surface of the windshield. That is, since the two outer surfaces of the windshield have small irregularities, it is possible to reduce the fluoroscopic distortion when the object outside the vehicle is viewed from the inside of the vehicle through the windshield.

(3) In the above embodiment, both the glass plates 1 and 2 are arranged so that the streaks 150 of the outer glass plate 1 and the streaks 250 of the inner glass plate 2 are orthogonal to each other. On the other hand, for example, when the lines 150 and 250 of both glass plates 1 and 2 extend in the same direction, the lines on the outer surface of the windshield and the lines on the outer surface of the vehicle are combined, and the entire windshield There is a possibility that the change in thickness will be large. This may increase fluoroscopic distortion. Therefore, in the present embodiment, since the streaks 150 and 250 of both the glass plates 1 and 2 are orthogonal to each other, it is possible to prevent the unevenness from increasing and thereby suppress the fluoroscopic distortion.

<9. Modification example>
Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. Then, the plurality of modifications shown below can be combined as appropriate.

<9-1>
In the above embodiment, the end face 15 and the second surface 102 are orthogonal to each other with respect to the outer glass plate 1 before polishing the end face. For example, as shown in FIG. 16, the end face 15 and the second surface 102 are before polishing. It is also possible to polish the end face 15 so that the one surface 101 is orthogonal to each other and the edge edges S11 and S21 face each other.

<9-2>
In the above embodiment, the inner glass plate 2 is made into a flat plate, but as shown in FIG. 17, the inner glass plate 2 can also be formed in a wedge shape like the outer glass plate 1. Also in this case, the edge edges S11 and S21 are arranged so as to face each other. Further, the inner glass plate 2 may be formed into a wedge shape and the outer glass plate 1 may be formed into a flat plate shape.

<9-3>
Further, as shown in FIG. 18, the outermost outermost edges 15 and 25 of the outer glass plate 1 and the inner glass plate 2 do not necessarily have to coincide with each other, and may be offset from each other. Even if they are displaced in this way, if the edge edges S11 and S21 face each other, the same effect as that of the above embodiment can be obtained.

<9-4>
In the above embodiment, the entire end face of each glass plate is formed in an arcuate cross section so that the cross section of the end face is only a curved line, but the present invention is not limited to this. That is, it is also possible to polish only the corners of the first surface and the second surface and the end surface of each glass plate in an arc shape, and form a linear portion between the corners in the cross section of the end surface. Therefore, not only when the entire end face is formed into an arc shape, but also when only the corner portion is formed into an arc shape or when the corner portion is chamfered as described above, the "end face is formed into an arc shape" in the present invention. It is a concept included in "is", and even in such a form, if the edges are opposed to each other, the effect of improving the appearance can be obtained as in the above embodiment. Further, the arc shape is formed by arcs having the same radius of curvature, and also includes a case where arcs having a plurality of radii of curvature are combined. Further, the "edge" according to the present invention means a position where bending is started.

<9-5>
In the above embodiment, the outer glass plate 1 and the inner glass plate 2 are arranged so that the top surfaces face each other, but the present invention is not limited to this. For example, the bottom surfaces may be arranged so as to face each other. Further, the top surface and the bottom surface may be arranged so as to face each other.

As described above, when the bottom surface is the outer surface of the windshield, there is an advantage that the fluoroscopic distortion can be suppressed, but the bottom surface is advantageous for laminating the ceramic shielding layer 4. Therefore, it is sufficient to consider which surface faces each other according to the application. In addition to the shielding layer 4, such a bottom surface is also suitable for laminating antenna elements such as copper and silver by printing or the like.

<9-6>
In the above embodiment, the streaks of the outer glass plate 1 and the inner glass plate 2 are orthogonal to each other, but they can also be parallel to each other.

<9-7>
The shape of the shielding layer 4 is not particularly limited, and various shapes are possible. For example, it is possible to form a shielding layer provided with a window so that light can be irradiated by a sensor or an external image can be taken by a camera.

<9-8>
The method of forming the outer glass plate 1 and the inner glass plate 2 in a wedge shape is not particularly limited, and methods other than those described above are also possible.

<9-9>
In the above embodiment, the edge of the interlayer film 3 is cut so as to substantially coincide with the outermost side of the outer glass plate 1 and the inner glass plate 2, but as shown in FIG. 19, the outer glass plate 1 and the inner side are cut. It is also possible to cut the interlayer film 3 inside the outermost side of the glass plate 2, for example, in the vicinity of the edge S11 and S21 described above.

1 Outer glass plate (first glass plate)
2 Inner glass plate (second glass plate)
3 Intermediate membrane

Claims (13)

A first glass plate having a first surface and a second surface and a first surface and a second surface are arranged so that the first surface and the second surface of the first glass plate face each other. 2 glass plates and
An interlayer film sandwiched between the first glass plate and the second glass plate,
With
The first glass plate has a first end portion and a second end portion facing the first end portion, and is formed so that the thickness decreases from the first end portion to the second end portion.
The end face connecting the first surface and the second surface of the first glass plate is formed in an arc shape in cross section.
The end face connecting the first surface and the second surface of the second glass plate is formed in an arc shape in cross section.
The end surface of the first glass plate on the second surface side and the end surface of the second glass plate on the first surface side are configured to face each other.
A windshield in which the outermost side of the end face of the first glass plate and the outermost side of the end face of the second glass plate substantially coincide with each other in the plane direction of the interlayer film . The second glass plate has a first end portion and a second end portion corresponding to the first end portion and the second end portion of the first glass plate.
The windshield according to claim 1, wherein the second glass plate is formed so that the thickness decreases from the first end portion to the second end portion. The first glass plate and the second glass plate have different concentrations of tin oxide on the first surface and the second surface, respectively.
The first glass plate and the second glass plate are arranged so that the surfaces having a high concentration of tin oxide or the surfaces having a low concentration of tin oxide face each other, according to claim 1 or 2. Windshield. The windshield according to claim 3, wherein the first glass plate and the second glass plate are arranged so that the surfaces having a high concentration of tin oxide face each other. The windshield according to claim 1, which is formed of a flat plate having a substantially constant thickness of the second glass plate. The first glass plate and the second glass plate have different concentrations of tin oxide on the first surface and the second surface, respectively.
The surface of the first glass plate having a low tin oxide concentration and the surface of the second glass plate having a low tin oxide concentration are arranged so as to face each other.
The windshield according to claim 5, wherein at least one of a shielding layer and an antenna is laminated on the second surface of the second glass plate. The first glass plate has streaks formed on it.
The windshield according to any one of claims 1 to 6, wherein the second glass plate is formed with streaks orthogonal to the streaks of the first glass plate. At the first end portion, the angle formed by the tangent line passing through the boundary between the second surface and the end surface of the first glass plate and in contact with the end surface and the second surface is θ1,
At the second end, the angle formed by the tangent line that passes through the boundary between the second surface and the end surface of the first glass plate and is in contact with the end surface and the second surface is θ2.
When stipulated
The windshield according to any one of claims 1 to 7, which satisfies θ1 = θ2. The windshield according to any one of claims 1 to 8, wherein the angle formed by the first surface and the second surface of the outer glass plate is 0.2 to 0.7 mrad. The windshield according to any one of claims 1 to 9, wherein the edge of the interlayer film is located at a position substantially coincident with the outermost side of the end face of the first glass plate and the second glass plate. The windshield according to any one of claims 1 to 9, wherein the edge of the interlayer film is inside the outermost end faces of the first glass plate and the second glass plate. The edge of the interlayer film is located at a position that substantially coincides with the edge of the first glass plate on the second surface side and the edge of the second glass plate on the first surface side. The windshield according to any one of claims 1 to 9. It has a first surface and a second surface, and also has a first end portion and a second end portion facing the first end portion, so that the thickness decreases from the first end portion to the second end portion. Steps to prepare the first glass plate formed in
A step of preparing a second glass plate having a first surface and a second surface,
A step of preparing a grindstone that is a cylindrical grindstone rotatably supported around an axis and in which the cross-sectional shape of the outer peripheral surface in the axial direction is formed in an arc shape that is convex inward in the radial direction.
In the first glass plate, a step of polishing an end surface connecting the first surface and the second surface, in which the second surface and the end surface are arranged so as to be orthogonal to each other, and the grindstone is rotated. A step of arranging the grindstone so that the shaft and the end face are parallel to each other, and then polishing the end face in an arc shape over the entire circumference by the grindstone.
In the second glass plate, a step of polishing an end surface connecting the first surface and the second surface, in which the first surface and the end surface are arranged so as to be orthogonal to each other, and the grindstone is rotated. in terms of a shaft and the end face is arranged the grinding wheel so as to be parallel, comprising the steps of polishing in an arc over the end face the entire circumference by the grinding stone, cut in the polishing of the second glass plate In the step, the amount is made substantially the same as the amount of cut in the polishing of the first glass plate .
An interlayer film is arranged between the second surface of the first glass plate and the first surface of the second glass plate, and the outermost positions of the end faces of the first and second glass plates are the same in the plane direction. on you, the steps of integrated by applying a pressure,
How to make a windshield.

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