Front windshield, manufacturing method therefor, and vehicle

Abstract

A front windshield (200), a manufacturing method therefor, and a vehicle. The front windshield (200) comprises: an outer glass layer (1) having a first surface (11) and a second surface (12) arranged opposite to each other; an inner glass layer (3) having a third surface (31) and a fourth surface (32) arranged opposite to each other; and an intermediate thermoplastic layer (2) sandwiched between the second surface (12) and the third surface (31). The front windshield (200) is provided with a first weakened area (203). An adult headform impactor impacts the first weakened area (203) so that the first weakened area (203) is broken, and the adult headform impactor impacts a dashboard (100) after the first weakened area (203) is broken. The adult headform impactor has a first speed V1 when coming into contact with the first surface (11) of the first weakened area (203), the adult headform impactor has a second speed V2 when the fourth surface (32) of the first weakened area (203) is broken, and V1 and V2 satisfy: V1=11.1±0.2 m / s, and V1-V2=0.3-2.2 m / s.

Description

Front windshield, manufacturing method thereof, and vehicle

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on October 24, 2023, with application number 202311384231.2 and application name “Front windshield and its manufacturing method, vehicle”, all contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of glass technology, and in particular to a front windshield, a manufacturing method thereof, and a vehicle. Background Art

[0003] With the booming economy and the continuous advancement of the automotive industry, collisions between pedestrians and vehicles caused by right-of-way violations are becoming increasingly severe and increasing in number. Pedestrian accidents account for 20% of all traffic accidents, with a mortality rate reaching 30%. The most common injury is caused by pedestrians' heads striking the windshield. However, traditional windshield safety designs primarily focus on protecting the driver and passengers, potentially exposing pedestrians to serious head injuries.

[0004] To this end, windshields are subject to relevant head tests to ensure they can break appropriately, thus protecting pedestrians' heads. However, if the windshield breaks too deeply, the pedestrian's head will strike the vehicle's instrument panel a second time, causing secondary damage that is often greater than the primary damage to the windshield, further increasing the overall damage sustained by the pedestrian and leading to a further increase in the casualty rate.

[0005] Summary of the Invention

[0006] Based on this, it is necessary to provide a front windshield and a manufacturing method thereof, and a vehicle, which can reduce the overall damage suffered by pedestrians after colliding with the front windshield and have better comprehensive safety performance.

[0007] A first aspect of an embodiment of the present application provides a front windshield installed on a vehicle including a dashboard, the front windshield comprising:

[0008] The outer glass has a first surface and a second surface disposed opposite to each other;

[0009] The inner glass has a third surface and a fourth surface disposed opposite to each other;

[0010] and a thermoplastic intermediate layer sandwiched between the second surface and the third surface;

[0011] The front windshield has a first weakened area, and the first weakened area is tested using an adult head-shaped impactor, wherein the adult head-shaped impactor impacts the first weakened area to break the first weakened area, and the adult head-shaped impactor impacts the instrument panel after the first weakened area breaks;

[0012] The adult head-shaped impactor has a first speed V1 when contacting the first surface of the first weakened zone, and has a second speed V2 when the fourth surface of the first weakened zone is broken, and V1 and V2 satisfy: V1 = 11.1 ± 0.2 m / s, V1-V2 = 0.3 ~ 2.2 m / s.

[0013] A second aspect of the embodiments of the present application provides a method for manufacturing the front windshield, comprising the following steps:

[0014] Step 1, providing a curved outer layer of glass and an inner layer of glass, wherein the outer layer of glass has a first surface and a second surface opposite to each other, and the inner layer of glass has a third surface and a fourth surface opposite to each other;

[0015] Step 2: providing a thermoplastic intermediate layer, and sequentially laminating the outer glass, the thermoplastic intermediate layer, and the inner glass to form a laminated glass structure;

[0016] Step 3: heating, evacuating, and / or applying pressure to the laminated glass structure to obtain the front windshield, wherein the front windshield has the first weakened area.

[0017] A third aspect of an embodiment of the present application provides a vehicle, comprising an instrument panel and the front windshield as described above, wherein the instrument panel is arranged at a lower side position close to the front windshield.

[0018] The technical solution of the present application has the following significant beneficial effects: the front windshield, its manufacturing method, and the vehicle described in the present application can reduce the primary damage to the pedestrian's head caused by the front windshield when the pedestrian collides with the vehicle, and reduce the secondary damage to the pedestrian's head caused by the dashboard, so that the total damage value to the pedestrian's head is greatly reduced, and ultimately the overall damage caused by the collision between the pedestrian and the front windshield is reduced, so that the collision protection of the pedestrian and the safety protection of the people in the car can be taken into account, thereby improving the comprehensive safety performance of the windshield.

[0019] The details of one or more embodiments of the present application are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the present application will become apparent from the description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG1 is a schematic structural diagram of the vehicle provided in this application.

[0021] FIG2 is a schematic diagram of the cross-sectional structure of the front windshield provided in this application.

[0022] FIG3 is an impact curve of the impact time and the resultant acceleration obtained by testing a conventional windshield according to the standard GB24550.

[0023] FIG4 is a schematic diagram of the front view structure of a windshield provided in an embodiment of the present application.

[0024] FIG5 is an impact curve of the front windshield provided in the present application obtained by testing the impact time and the synthetic acceleration according to the standard GB24550.

[0025] FIG6 is a schematic front view of the structure of a windshield provided in another embodiment of the present application.

[0026] FIG7 is a schematic diagram of the front view structure of a windshield provided in yet another embodiment of the present application. DETAILED DESCRIPTION

[0027] To facilitate understanding of the present application, a more comprehensive description of the present application will be provided below with reference to the accompanying drawings. The accompanying drawings illustrate preferred embodiments of the present application. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. It should be understood that these embodiments are provided to provide a more thorough and comprehensive understanding of the disclosure of the present application.

[0028] Referring to FIG1 , the present application provides a vehicle, comprising an instrument panel 100 and a front windshield 200, wherein the instrument panel 100 is disposed at a lower position adjacent to the front windshield 200. The vehicle provided in the present application may be, but is not limited to, a sedan, a truck, a pickup truck, a commercial vehicle, a bus, and an off-road vehicle, and the present application does not impose any restrictions thereon. The front windshield 200 is disposed at an angle to the instrument panel 100, and the angle is substantially equal to the loading angle of the front windshield 200. The loading angle of the front windshield 200 is the angle between the front windshield 200 and the horizontal plane when the front windshield 200 is in the loaded state, indicating the degree of inclination of the front windshield 200, and the loading angle is typically 18° to 45°, such as 25°, 30°, 35°, 40°, and the like.

[0029] In some embodiments, a head-up display projector 300 is installed in the instrument panel 100. The head-up display projector 300 can project the required information onto the front windshield 200. The light projected by the head-up display projector 300 is reflected or diffracted by the front windshield 200 and enters the driver's eyes, allowing the driver to view the required driving information, road conditions, and even entertainment information without lowering their heads. In other embodiments, a passenger airbag 400 is installed in the instrument panel 100. The passenger airbag 400 can be deployed from the instrument panel 100 in the event of a vehicle collision, thereby protecting the safety of the vehicle occupants.

[0030] 2 , the front windshield 200 provided in the present application adopts a laminated glass structure, which specifically includes an outer layer of glass 1, a thermoplastic interlayer 2, and an inner layer of glass 3; the outer layer of glass 1 has a first surface 11 and a second surface 12 opposite to each other, the inner layer of glass 3 has a third surface 31 and a fourth surface 32 opposite to each other, and the thermoplastic interlayer 2 is sandwiched between the second surface 12 and the third surface 31.

[0031] The outer glass 1 is transparent glass or tinted glass, has a thickness of 0.7 mm to 4 mm, and has a visible light transmittance greater than 70%. The inner glass 3 is transparent glass or tinted glass, has a thickness of 0.7 mm to 4 mm, and has a visible light transmittance greater than 70%. The total iron content (calculated as Fe2O3) of the transparent glass is less than or equal to 0.1%, even less than or equal to 0.05%, and further less than or equal to 0.01%, and the visible light transmittance of the transparent glass is 80% to 95%; the total iron content (calculated as Fe2O3) of the tinted glass is 0.1% to 0.8%, even 0.1% to 0.5%, and the visible light transmittance of the tinted glass is 75% to 90%. For example, the outer glass 1 can be a transparent glass with a thickness of 2.1 mm and a visible light transmittance of 89%, and the inner glass 3 can be a green glass with a thickness of 1.6 mm and a visible light transmittance of 83%, or a green glass with a thickness of 2.1 mm and a visible light transmittance of 80%.

[0032] The thermoplastic interlayer 2 is a transparent thermoplastic polymer film or a colored thermoplastic polymer film, and has a thickness of 0.38 mm to 2.28 mm. For example, the thickness of the thermoplastic interlayer 2 may be, but is not limited to, 0.38 mm, 0.76 mm, 1.14 mm, 1.52 mm, 1.9 mm, 2.28 mm, or other values ​​between 0.38 mm and 2.28 mm. The material of the thermoplastic polymer film may be selected from at least one of polyvinyl butyral (PVB), polyurethane (PU), ethylene-vinyl acetate copolymer (EVA), and ionomer (SGP). When the thermoplastic interlayer 2 is a transparent thermoplastic polymer, the visible light transmittance of the transparent thermoplastic polymer is greater than or equal to 80%. For example, the visible light transmittance of the thermoplastic interlayer 2 may be, but is not limited to, 80%, 85%, 90%, or 95%. When the thermoplastic intermediate layer 2 is a colored thermoplastic polymer film, the visible light transmittance of the colored thermoplastic polymer film is greater than 70%. For example, the visible light transmittance of the thermoplastic intermediate layer 2 may be, but is not limited to, 75%, 80%, 85%, or 90%. The colored thermoplastic polymer film may be a gray thermoplastic polymer film, a green thermoplastic polymer film, or a blue thermoplastic polymer film.

[0033] The outer glass 1, thermoplastic interlayer 2, and inner glass 3 are processed through an automotive glass production process to form a laminated glass windshield 200. The windshield 200 meets the requirements of the Chinese standard GB9656, as well as the requirements of automotive glass standards in Europe, the United States, and other countries. When the windshield 200 is installed on a vehicle, the outer glass 1 is located on the outside of the vehicle, and the first surface 11 is the outer surface of the windshield 200 exposed to the outside of the vehicle. The inner glass 3 is located on the inside of the vehicle, and the fourth surface 32 is the inner surface of the windshield 200 exposed to the inside of the vehicle. When a pedestrian collides with the windshield 200, the pedestrian's head first contacts the first surface 11 of the outer glass 1. If the windshield 200 does not break, the pedestrian's head will be subjected to a significant impact from the windshield 200. If the windshield 200 breaks, the pedestrian's head will partially or completely pass through the fourth surface 32 of the inner glass 3.

[0034] Regarding the safety requirements for the front windshield 200, in addition to meeting the traditional basic requirements of protecting the safety of the occupants of the vehicle, it must not only prevent the occupants from passing through the vehicle during a collision, but also be able to not easily break when colliding with flying objects such as flying rocks from outside the vehicle, and have impact resistance to flying objects such as flying rocks from outside the vehicle. These safety requirements must be met by traditional windshields, but more and more countries require that the front windshield also protect pedestrians who collide with the vehicle and minimize the damage to the pedestrian's head caused by the windshield in the event of a collision. According to the provisions of the Chinese standard GB24550, the head injury index (HIC) is used to evaluate the degree of damage to the pedestrian's head caused by the windshield in the event of a collision. The head injury index (HIC) is calculated according to the following formula:

[0035] Where a is the measured composite acceleration in g (1 g = 9.81 m / s 2 );

[0036] t1 and t2 are two moments in the impact process (in seconds), representing a certain time interval between the start and end of recording. During this time interval, HIC takes the maximum value (t2-t1≤15ms).

[0037] According to the applicant's research, after a pedestrian's head collides with the front windshield 200, if the front windshield 200 does not break, the HIC of the front windshield 200 must be greater than 1000, or even greater than 1700. The pedestrian's head will be subjected to a huge impact from the front windshield 200, causing serious primary injury to the pedestrian's head; if the front windshield 200 breaks, the HIC of the front windshield 200 may be greater than 1000 or less than 1000; in order to better protect the pedestrian's head, the HIC of the front windshield 200 provided in this application is less than 1000, so as to minimize the primary injury to the pedestrian's head.

[0038] According to the applicant's further research, the applicant surprisingly found that if a front windshield 200 with an HIC of less than 1000 is provided, after a pedestrian's head collides with the front windshield 200, the front windshield 200 will break, and the pedestrian's head will partially or completely pass through the fourth surface 32 of the inner layer of glass 3. Due to the structural design of the vehicle and the angle of the pedestrian's collision with the vehicle, the pedestrian's head will usually directly hit the lower half of the front windshield 200, or even the area near the bottom edge of the front windshield 200. After passing through or passing through the fourth surface 32, the pedestrian's head will further hit the dashboard 100 below the front windshield 200, causing secondary damage to the pedestrian's head from the dashboard 100. In particular, when the dashboard 100 is installed with a head-up display projector 300, a passenger airbag 400, or other hard and sharp decorative components, the secondary damage caused to the pedestrian's head by the dashboard 100 may be more serious than the primary damage caused to the pedestrian's head by the front windshield 200.

[0039] Referring to Figure 3, multiple conventional windshields were tested using an adult head-shaped impactor according to standard GB24550, simulating the process of a pedestrian's head impacting the front windshield 200 after a collision with a vehicle. An accelerometer and a data acquisition device were used to obtain impact curves representing impact time and resultant acceleration. Figure 3 shows five sets of impact curves, with the abscissa representing the impact time t (Time) in milliseconds (ms) and the ordinate representing the resultant acceleration a (acceleration) in g. In this application, the adult head-shaped impactor sequentially impacts the windshield and instrument panel 100, then experiences resistance and decelerates. For ease of illustration and description, the resultant acceleration a is taken as an absolute value.

[0040] In FIG3 , dashed box 2000 shows an impact curve of the impact time and resultant acceleration from the time an adult head impactor contacts the first surface of windshield 200 until the windshield 200 breaks, typically completing the impact within 5 ms. Dashed box 3000 shows an impact curve of the impact time and resultant acceleration within 15 ms from the time windshield 200 breaks until the impact with instrument panel 100. Based on the curves within dashed boxes 2000 and 3000 and the head injury criteria (HIC) calculation formula, two HICs can be calculated. For the five sets of impact curves for the traditional windshield shown in Figure 3, the resultant acceleration within the dotted box 3000 is significantly greater than the resultant acceleration within the dotted box 2000, and the HIC calculated based on the curve within the dotted box 3000 is also significantly greater than the HIC calculated based on the curve within the dotted box 2000. In fact, the HIC calculated based on the curve within the dotted box 3000 is greater than 1000, which means that the dashboard 100 causes more serious secondary damage to the pedestrian's head and even fails to meet the standard requirement of HIC less than 1000.

[0041] Based on this, the present application further optimizes the front windshield 200 with an HIC of less than 1000. Referring to Figure 4, a first weakened area 203 is set on the front windshield 200 in an area corresponding to the instrument panel 100, and the first weakened area 203 is tested using an adult head-shaped impactor. The adult head-shaped impactor impacts the first weakened area 203 to break the first weakened area 203. After the first weakened area 203 is broken, the adult head-shaped impactor impacts the instrument panel 100; the adult head-shaped impactor has a first velocity V1 when contacting the first surface 11 of the first weakened area 203, and has a second velocity V2 when the fourth surface 32 of the first weakened area 203 is broken, and V1 and V2 satisfy the following: V1 = 11.1 ± 0.2 m / s, V1 - V2 = 0.3 m / s to 2.2 m / s. The above-mentioned head injury index (HIC) formula shows that the magnitude of the HIC is directly related to the resultant acceleration a and the time interval t2-t1 during the impact. The larger the velocity difference V1-V2, the greater the deceleration resistance generated by the front windshield 200 to the adult head impactor, that is, the greater the resultant acceleration a; or the front windshield 200 is less likely to break, that is, the longer the collision time between the adult head impactor and the front windshield 200; thus, the HIC of the front windshield 200 is greater than 1000, or even greater than 200. 0, the front windshield 200 causes very serious primary damage to the pedestrian's head; on the other hand, the smaller the speed difference V1-V2, the easier it is for the front windshield 200 to break, that is, the easier it is for an adult head-shaped impactor to penetrate the front windshield 200, and even the adult head-shaped impactor penetrates the front windshield 200 at the moment of collision, impacting the instrument panel 100 at a very high speed, thereby causing the HIC of the instrument panel 100 to be greater than 1000, or even greater than 2000, causing very serious secondary damage to the pedestrian's head by the instrument panel 100. In the present application, by providing the first weakened area 203 on the front windshield 200, under the premise that the speed of V1 is basically fixed, the speed difference between V1 and V2 is controlled to be maintained within 0.3m / s to 2.2m / s, and specific examples include 0.3m / s, 0.4m / s, 0.5m / s, 0.6m / s, 0.7m / s, 0.8m / s, 0.9m / s, 1.0m / s, 1.1m / s, 1.2m / s, 1.3m / s, 1.4m / s, 1.5m / s, 1.6m / s, 1.7m / s, 1.8m / s, 1.9m / s, 2.0m / s, 2.1m / s, 2.2m / s, etc., so that the HIC values ​​of the front windshield 200 and the instrument panel 100 can be effectively controlled on the basis of meeting the basic requirements of protecting the safety of people in the car. This will not only reduce the primary damage to the pedestrian's head caused by the front windshield 200, but also reduce the secondary damage to the pedestrian's head caused by the instrument panel 100, thereby greatly reducing the total damage value to the pedestrian's head.It is understood that the testing of the first weakened area 203 using an adult headform impactor can be conducted in accordance with Chinese standard GB24550, or can be conducted using EU regulation ECEUNR127, the European New Car Assessment Program (E-NCAP), the China New Car Assessment Program (C-NCAP), or the China Insurance Automobile Safety Index (C-IASI). In the present application, the testing is preferably conducted in accordance with Chinese standard GB24550, and the adult headform impactor is selected from the one specified in Chinese standard GB24550.

[0042] Referring to FIG. 5 , multiple front windshields 200 further optimized according to the present application were tested using an adult headform impactor according to standard GB 24550, simulating the process of a pedestrian's head impacting the front windshield 200 after a collision with a vehicle. An acceleration sensor and a data acquisition device were used to obtain impact curves of impact time and resultant acceleration. The dashed box 2001 represents the impact curve of the time and resultant acceleration from the time the adult headform impactor contacts the first surface of the windshield 200 until the windshield 200 breaks. The dashed box 3001 represents the impact curve of the time and resultant acceleration within 15 milliseconds from the time the windshield 200 breaks until it impacts the instrument panel 100. The adult headform impactor exhibits a first maximum resultant acceleration a5 within 0 to 5 milliseconds after impacting the first weakened zone, with a5 being less than or equal to 180 g. The adult head impactor exhibits a second maximum resultant acceleration a15 within 5 to 15 milliseconds after impacting the first weakened zone 203, and a5 is generally greater than a15. This further reduces secondary damage to the pedestrian's head caused by the instrument panel 100, meets the standard requirement of an HIC of less than 1000, and significantly reduces the total damage to the pedestrian's head. The front windshield 200 can provide both collision protection for pedestrians and safety protection for vehicle occupants, resulting in improved overall safety performance.

[0043] In some embodiments, V1-V2=0.6m / s to 2.0m / s. The speed of V1 is essentially fixed according to testing standards such as Chinese standard GB24550. Maintaining the speed difference between V1 and V2 within a range of 0.6m / s to 2.0m / s allows the resultant acceleration a during impact and the rupture time of the front windshield 200 to fall within a more reasonable range, thereby more effectively controlling the HIC value. This reduces both primary head damage from the front windshield 200 and secondary head damage from the instrument panel 100, significantly reducing the total head damage to the pedestrian while meeting the standard requirement of an HIC of less than 1000.

[0044] In some embodiments, after an adult headform impactor strikes the front windshield 200, the time it takes for the front windshield 200 to rupture is shortened to less than 3 ms. Specifically, the time it takes for the adult headform impactor to impact the first weakened zone 203 and rupture the first weakened zone 203 is less than or equal to 3 ms, thereby further reducing the primary injury caused by the front windshield 200 to a pedestrian's head. During the rupture process of the front windshield 200, the outer glass 1 exhibits an external maximum composite acceleration aO with respect to the adult headform impactor, while the inner glass 3 exhibits an internal maximum composite acceleration a1 with respect to the adult headform impactor. Specifically, the adult headform impactor exhibits two peaks within 0 to 5 ms after impacting the first weakened zone 203, specifically corresponding to the two peaks in the dashed box 2001. Typically, the inner glass 3 ruptures earlier than the outer glass 1, and the external maximum composite acceleration aO is greater than the internal maximum composite acceleration a1. In other embodiments, the external maximum composite acceleration aO is less than the internal maximum composite acceleration a1. In some further embodiments, the adult headform impactor has only one peak within the first 0 to 5 ms after impacting the first weakened area 203 .

[0045] In some embodiments, the first maximum resultant acceleration a5 is typically less than or equal to 180g, and the second maximum resultant acceleration a15 is typically less than or equal to 100g, thereby further reducing primary injury to the pedestrian's head caused by the front windshield 200 and secondary injury to the pedestrian's head caused by the instrument panel 100. Preferably, the first maximum resultant acceleration a5 is less than or equal to 150g, and the second maximum resultant acceleration a15 is less than or equal to 80g.

[0046] In some embodiments, the adult head impactor has a first head injury index HIC1 within 0-5 ms after impacting the first weakened zone 203, and a second head injury index HIC2 within 5-15 ms, wherein 100≤HIC1≤650, and HIC2<1000. By providing the first weakened zone 203 on the front windshield 200 and controlling the velocity difference between V1 and V2 to remain within a certain range, the HIC value is controlled to meet 100≤HIC1≤650, and HIC2<1000. This not only meets the basic requirements for protecting the safety of vehicle occupants, but also reduces both primary head injury caused by the front windshield 200 and secondary head injury caused by the instrument panel 100, thereby meeting the standard requirement of HIC less than 1000.

[0047] In some embodiments, the second head injury index HIC2 ≤ 650, HIC2 is less than HIC1, which is more conducive to reducing the secondary damage caused by the instrument panel 100 to the pedestrian's head. According to the applicant's research, if HIC1 is too small, it will cause the adult head impactor to directly penetrate the front windshield 200. Although the primary damage caused by the front windshield 200 to the pedestrian's head is relatively small, the secondary damage caused by the instrument panel 100 to the pedestrian's head is very large, making HIC2 significantly greater than 1000, and it is difficult to meet the impact resistance requirements for flying objects such as flying stones outside the vehicle. Therefore, after the adult head impactor impacts the first weakened area 203, the first weakened area 203 is preferably broken but not completely penetrated. The first head injury index HIC1 can be cited as Examples are 100, 150, 180, 200, 220, 250, 280, 300, 320, 350, 370, 400, 430, 450, 480, 500, 550, 600, 650; the first head injury index HIC1 can be 100, 150, 180, 200, 220, 250, 280, 300, 320, 350, 370, 400, 430, 450, 480, 500, 550, 600, 650; preferably, 200≤HIC1≤500, HIC2≤500.

[0048] In some embodiments, to further reduce the risk of primary injury to pedestrians' heads from the front windshield 200, the front windshield 200 further comprises a second weakened area 204, which is also located within the transparent area 201. When the second weakened area 204 is tested using an adult head impactor, the adult head impactor exhibits a third head injury index (HIC3) within 0 to 15 milliseconds after impacting the second weakened area 204, where HIC3 is less than 1000. Preferably, 100 ≤ HIC3 ≤ 900, and specific examples include 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, and the like. In the present application, the first weakened zone 203 is mainly used to protect the pedestrian's head, and can reduce the primary damage to the pedestrian's head caused by the front windshield 200 and reduce the secondary damage to the pedestrian's head caused by the instrument panel 100; the second weakened zone 204 is mainly used to protect the occupants of the vehicle, while taking into account the protection of the pedestrian's head, and can reduce the primary damage to the pedestrian's head caused by the front windshield 200; HIC1 and HIC3 preferably satisfy HIC3 greater than HIC1, 200≤HIC3≤800.

[0049] In some embodiments, the front windshield 200 has a transparent area 201 and a shielding area 202 surrounded by the transparent area 201. The transparent area 201 is located in the central area of ​​the front windshield 200 and has a high visible light transmittance that meets safety standards. The visible light transmittance of the transparent area 201 is greater than or equal to 70%.

[0050] The shielding area 202 is disposed around the perimeter of the front windshield 200. The shielding area 202 has a low visible light transmittance, less than or equal to 10%. The shielding area 202 is used to shield and protect the vehicle's interior components, preventing them from aging and damage due to direct sunlight, thereby increasing the service life of the vehicle's interior components. The shielding area 202 also shields the vehicle's interior components to ensure an overall aesthetic appearance when viewed from the outside. Preferably, the visible light transmittance of the shielding area 202 is less than or equal to 5%, more preferably less than or equal to 1%, and even more preferably less than or equal to 0.5%. The visible light transmittance of the shielding area 202 is substantially zero, i.e., the shielding area 202 is completely opaque.

[0051] The shielding area 202 may be formed by at least one of a dark-colored printed layer, a dark-colored polymer film, and a dimming element.

[0052] The dark printed layer 4 can be made of ceramic ink or UV ink. The ceramic ink or UV ink is printed on the second surface 12 via a process such as screen printing or inkjet printing, and then cured or sintered at high temperature to form the dark printed layer 4. The dark printed layer is preferably black, brown, or tan in color. The dark printed layer 4 surrounds the peripheral edge of the second surface 12. It is understood that the dark printed layer 4 can also be located only on the third surface 31, only on the fourth surface 32, on both the second surface 12 and the fourth surface 32, on both the second surface 12 and the third surface 31, on both the third surface 31 and the fourth surface 32, or on all three surfaces.

[0053] The dark polymer film can be a polymer film with body coloring, and the material of the polymer film is a thermoplastic resin, such as polyvinyl butyral (PVB), polyethylene terephthalate (PET), polyvinyl chloride (PVC), ethylene-vinyl acetate copolymer (EVA), thermoplastic polyurethane elastomer (TPU), polyolefin elastomer (POE), polyurethane (PU) or ionomeric polymer film (SGP), etc., preferably PET or PVB. For example, a coloring component is added during the manufacturing process of the polymer film to achieve body coloring to obtain a black or brown polymer film, etc.; the dark polymer film can also be a polymer film with pigment printed on the surface, for example, black or brown pigment or paint is printed on the surface of the polymer film, etc.

[0054] The dimming element can be a polymer dispersed liquid crystal film (PDLC), a suspended particle film (SPD), an electrochromic film (EC), a dye liquid crystal film (LC), etc. The minimum visible light transmittance of the dimming element is less than or equal to 5%, such as 3%, 2%, 1%, 0.5%, or 0%. The maximum visible light transmittance of the dimming element is set as needed, such as 10%, 20%, 30%, 50%, 70%, or 80%. For example, the visible light transmittance of the dimming element can be adjusted between 0% and 20%, or between 0.5% and 50%, or between 0% and 70%, etc., so as to meet the visible light transmittance requirements in multiple scenarios.

[0055] In some embodiments, the first weakened area 203 and the second weakened area 204 are both located within the transparent area.

[0056] 4 , the first weakened area 203 is located within the transparent area 201 . The adult head impactor will continue to impact the instrument panel 100 after breaking the first weakened area 203 . Therefore, the first weakened area 203 is also referred to as an instrument panel weakened area or an IP weakened area.

[0057] The shielding area 202 includes a top shielding area 205, a left shielding area 206, a right shielding area 207 and a bottom shielding area 208. The top shielding area 205 is located in the top area of ​​the front windshield 200, the left shielding area 206 is located in the left area of ​​the front windshield 200, the right shielding area 207 is located in the right area of ​​the front windshield 200, and the bottom shielding area 208 is located in the bottom area of ​​the front windshield 200.

[0058] Specifically, the distance between the lower boundary of the first weakened zone 203 and the bottom shielding zone 208 is x, the distance between the left boundary of the first weakened zone 203 and the left shielding zone 206 is m, the distance between the right boundary of the first weakened zone 203 and the right shielding zone 207 is n, and the distance between the upper boundary and the lower boundary of the first weakened zone 203 is h, x is less than or equal to 15 mm, m is less than or equal to 50 mm, n is less than or equal to 50 mm, and h is equal to 100 mm to 300 mm. Specifically, x can be 15mm, 10mm, 5mm, 1mm, etc., m can be 50mm, 45mm, 40mm, 35mm, 30mm, 25mm, 20mm, 15mm, 10mm, 5mm, etc., n can be 50mm, 45mm, 40mm, 35mm, 30mm, 25mm, 20mm, 15mm, 10mm, 5mm, etc., and h can be 100mm, 120mm, 150mm, 180mm, 200mm, 230mm, 250mm, 280mm, 300mm, etc.

[0059] 4 , the second weakened area 204 is located within the transparent area 201. Specifically, the second weakened area 204 is located between the first weakened area 203 and the top shielding area 205. The distance between the upper boundary of the second weakened area 204 and the top shielding area 205 is y, the distance between the left boundary of the second weakened area 204 and the left shielding area 206 is m, and the distance between the right boundary of the second weakened area 204 and the right shielding area 207 is n. y is less than or equal to 100 mm, and examples of y include 5 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, etc.

[0060] In some embodiments, the ratio of the area of ​​the first weakened zone 203 to the area of ​​the transparent zone 201 is less than or equal to 1 / 3, the ratio of the area of ​​the second weakened zone 204 to the area of ​​the transparent zone 201 is less than or equal to 2 / 3, and the area of ​​the first weakened zone 203 is smaller than the area of ​​the second weakened zone 204.

[0061] 4 and 7 , the first weakened area 203 is adjacent to the second weakened area 204 .

[0062] To achieve the front windshield 200 having a first weakened zone 203 and a second weakened zone 204, the present application implements zoned weakening of the windshield to achieve different HIC zone control. For the first weakened zone 203, the peak value of the second maximum resultant acceleration a15 is further advanced and reduced, making a15 less than a5, significantly optimizing the overall impact curve.

[0063] In other embodiments, referring to Figure 6, a transition weakened zone 209 can be set between the lower boundary of the second weakened zone 204 and the upper boundary of the first weakened zone 203, and the area of ​​the transition weakened zone 209 is smaller than the area of ​​the first weakened zone 203. The transition weakened zone is tested using an adult head-shaped impactor. The adult head-shaped impactor has a fourth head injury index HIC4 within 0 to 15 ms after impacting the transition weakened zone, and HIC4 is greater than HIC1, and HIC4 is less than HIC3.

[0064] In some embodiments, when weakening the front windshield 200, other safety requirements must also be met. For example, the passenger airbag 400 will directly impact the inner layer of glass 3 after detonation. In order to protect the people in the car, it is preferred that the strength of the inner layer of glass 3 is greater than the strength of the outer layer of glass 1, the bending strength of the third surface 31 is greater than the bending strength of the second surface 12, and / or the bending strength of the fourth surface 32 is greater than the bending strength of the second surface 12.

[0065] The thickness of the thermoplastic interlayer 2 of a conventional front windshield 200 ranges from 0.76 mm to 1.52 mm. In some embodiments of the present application, the thickness of the thermoplastic interlayer 2 located in the first weakened zone 203 ranges from 0.38 mm to 0.6 mm, specifically 0.38 mm, 0.5 mm, 0.6 mm, etc., to better achieve the first weakened zone 203. Furthermore, to ensure the overall strength of the second weakened zone 204, the thickness of the thermoplastic interlayer 2 in the second weakened zone 204 is preferably at least 0.76 mm.

[0066] According to the applicant's research, the moisture content of the thermoplastic interlayer 2 affects the bond strength between the thermoplastic interlayer 2 and the outer glass 1 and inner glass 3. The moisture content of the thermoplastic interlayer 2 of a conventional windshield 200 is 0.45% to 0.55%, which can provide better bond strength and result in a higher HIC value for the windshield 200. In some embodiments of the present application, to achieve the first weakened zone 203 and the second weakened zone 204, the moisture content of the thermoplastic interlayer 2 described in the present application is 0.3%-0.4%, specifically 0.3%, 0.32%, 0.35%, 0.38%, 0.4%, etc.; or 0.6%-0.7%, specifically 0.6%, 0.61%, 0.63%, 0.65%, 0.68%, 0.7%, etc., thereby effectively controlling the HIC value.

[0067] One of the second surface 12 and the third surface 31 of the conventional front windshield 200 is an air surface and the other is a tin surface, so as to improve the bonding strength between them and the thermoplastic interlayer 2. In some embodiments of the present application, the outer layer of glass 1 and the inner layer of glass 3 are both float glass. Float glass is formed with an air surface and a tin surface during the production process, and the concentration of tin oxide on the tin surface is greater than that on the air surface.

[0068] Specifically, the second surface 12 and the third surface 31 are both tin surfaces or both are air surfaces. The second surface 12 and the third surface 31 are both tin surfaces, i.e., the concentration of tin oxide on the second surface 12 is greater than the concentration of tin oxide on the first surface 11, and the concentration of tin oxide on the third surface 31 is greater than the concentration of tin oxide on the fourth surface 32. Alternatively, the second surface 12 and the third surface 31 are both air surfaces, i.e., the concentration of tin oxide on the second surface 12 is less than the concentration of tin oxide on the first surface 11, and the concentration of tin oxide on the third surface 31 is less than the concentration of tin oxide on the fourth surface 32.

[0069] The conventional front windshield 200 has an outer glass 1 with a thickness of 2.1 mm and an inner glass 3 with a thickness of 2.1 mm, or an outer glass 1 with a thickness of 3.0 mm and an inner glass 3 with a thickness of 1.1 mm. This results in a break time of approximately 5 ms, or even approximately 6.5 ms, after an impact on the conventional front windshield 200. In the present application, it is preferred that the ratio of the thickness of the outer glass 1 to the thickness of the inner glass 3 be greater than or equal to 0.75 and less than 1, such as 0.75, 0.8, 0.85, 0.9, 0.95, 0.96, 0.97, 0.98, 0.99, etc. This allows the inner glass 3 and the outer glass 1 to break simultaneously or nearly simultaneously, thereby shortening the break time of the front windshield 200 after an impact to less than 3 ms. Specifically, for example, the thickness of the outer glass 1 is 1.6 mm and the thickness of the inner glass 3 is 2.1 mm, or the thickness of the outer glass 1 is 1.8 mm and the thickness of the inner glass 3 is 2 mm.

[0070] As shown in FIG2 , the present application further provides a weakening coating 5 on at least one of the second surface 12 , the third surface 31 , and the fourth surface 32 . The weakening coating 5 covers at least the first weakened area 203 , and preferably covers at least the first weakened area 203 and the second weakened area 204 . Further, the weakening coating 5 covers at least the transparent area 201 . During the manufacturing process of the front windshield 200 , the weakening coating 5 undergoes a heating and softening step, a bending and forming step, and an annealing step together with the outer layer of glass 1 or the inner layer of glass 3 . Since the weakening coating 5 has different heating and annealing rates from the outer layer of glass 1 or the inner layer of glass 3 , the glass surface where the weakening coating 5 is located generates mechanical stress on the interior of the glass, causing the tensile stress inside the glass to increase, while the compressive stress on the glass surface where the weakening coating 5 is located increases, thereby reducing the stress on the glass surface where the weakening coating 5 is not provided, thereby achieving the effect of making 100≤HIC1≤650 and HIC2<1000. The weakening coating 5 can be deposited on at least one of the second surface 12, the third surface 31, and the fourth surface 32 via physical vapor deposition (PVD) or a sol-gel method. The physical vapor deposition (PVD) method is preferably a magnetron sputtering process. It is understood that the weakening coating 5 not only weakens the windshield 200 but also provides the windshield 200 with its own functions, such as heat insulation, UV protection, electric heating for defrosting and defogging, increased P-polarized light reflectivity for HUD implementation, reduced visible light reflectivity, fog prevention, water repellency, and anti-glare.

[0071] In some embodiments, the weakened coating 5 includes at least one infrared reflective functional layer, which can be a metal layer, a metal alloy layer, or a transparent conductive oxide layer (TCO layer). The number of infrared reflective functional layers in the weakened coating 5 can be one, two, three, four, or even five. Taking into account the complexity of design, production difficulty, and manufacturing cost, the number of infrared reflective functional layers is preferably 2-4. It is understood that the weakened coating 5 also includes at least two dielectric layers, each infrared reflective functional layer being located between two adjacent dielectric layers. The dielectric layer has the function of protecting the infrared reflective functional layer from oxidation or corrosion on the one hand, and can also adjust the optical properties, mechanical properties, and reflection color of the weakened coating 5 on the other hand.

[0072] The metal layer can be made of gold (Au), silver (Ag), copper (Cu), or aluminum (Al). The metal alloy layer can be made of a silver alloy with a silver content greater than or equal to 90%, such as a silver-copper alloy, a silver-indium alloy, or a silver-aluminum alloy. The thickness of the metal layer or metal alloy layer is 5 nm to 20 nm. When the infrared reflective functional layer is a metal layer or a metal alloy layer, the weakening coating 5 is disposed on the second surface 12 or the third surface 31.

[0073] The infrared reflective functional layer may also be a transparent conductive oxide layer. The material of the transparent conductive oxide layer may be selected from at least one of ITO (indium tin oxide), NiCrOx, FTO (fluorine-doped tin oxide), ZnSnOx, and doped zinc oxide. The doping element in the doped zinc oxide may be at least one of aluminum, tungsten, hafnium, gallium, yttrium, niobium, and neodymium. Examples include AZO (aluminum-doped zinc oxide) and HAZO (AZO doped with hafnium and aluminum). In some embodiments, the thickness of the transparent conductive oxide layer is 50 nm to 300 nm. When the infrared reflective functional layer is a transparent conductive oxide layer, the weakening coating 5 is disposed on the second surface 12, the third surface 31, or the fourth surface 32.

[0074] In other embodiments, the weakened coating 5 comprises at least one laminated structure of a "high refractive index layer / low refractive index layer", the refractive index of the high refractive index layer is not less than 1.8, and the refractive index of the low refractive index layer is not higher than 1.7; the weakened coating 5 is used to reduce the visible light reflectivity of the front windshield 200, or to increase the P-polarized light reflectivity of the front windshield 200. Specifically, the weakened coating 5 may include 1-4 of the stacked structures, for example, the weakened coating 5 includes a stacked structure of a high refractive index layer / low refractive index layer, the high refractive index layer is directly arranged on the second surface 12, the third surface 31 or the fourth surface 32, and the low refractive index layer is arranged on the high refractive index layer; the weakened coating 5 includes a stacked structure of two high refractive index layers / low refractive index layers, that is, deposited outwardly in sequence as a first high refractive index layer, a first low refractive index layer, a second high refractive index layer and a second low refractive index layer, the first high refractive index layer is directly arranged on the second surface 12, the third surface 31 or the fourth surface 32; the weakened coating 5 includes a stacked structure of three high refractive index layers / low refractive index layers, that is, deposited outwardly in sequence as a first high refractive index layer, a first low refractive index layer, a second high refractive index layer, a second low refractive index layer, a third high refractive index layer and a third low refractive index layer, the first high refractive index layer is directly arranged on the second surface 12, the third surface 31 or the fourth surface 32.

[0075] The present application also provides a method for manufacturing the front windshield 200, comprising the following steps:

[0076] Step 1: providing a curved outer glass 1 and an inner glass 3 , wherein the outer glass 1 has a first surface 11 and a second surface 12 opposite to each other, and the inner glass 3 has a third surface 31 and a fourth surface 32 opposite to each other.

[0077] Step 2: providing a thermoplastic intermediate layer 2, and sequentially laminating the outer glass 1, the thermoplastic intermediate layer 2 and the inner glass 3 to form a laminated glass structure.

[0078] Step 3: heating, vacuuming and / or applying pressure to the laminated glass structure to obtain the front windshield 200 , wherein the front windshield 200 has the first weakened area 203 .

[0079] In some embodiments, the front windshield 200 has at least one weakening structure. The weakening structure is formed by at least one of the following weakening methods:

[0080] (1) Introducing an internal defect between the first surface and the second surface using a laser weakening method.

[0081] (2) Introducing internal defects between the third surface and the fourth surface using a laser weakening method.

[0082] (3) Microcracks are formed on the second surface using a physical friction weakening method.

[0083] (4) A chemical etching weakening method is used to form fracture lines on the second surface.

[0084] The weakened structure may be located in the first weakened area 203 . In addition, when the front windshield 200 has the second weakened area 204 , the weakened structure may be located in the second weakened area 204 .

[0085] It should be noted that, in the present application, the weakening structure may be located only in the first weakening zone 203, or multiple weakening structures may be located in the first weakening zone 203 and the second weakening zone 204 respectively. The weakening structure in the first weakening zone 203 may be the same as or different from the weakening structure in the second weakening zone 204, which shall be subject to the specific design.

[0086] In some embodiments, the curved outer glass 1 and inner glass 3 are obtained by subjecting flat glass to a heating and softening step, a bending and forming step, and an annealing step. Different process conditions are set for the heating and softening step, the bending and forming step, and the annealing step, thereby further adjusting the stress of the outer glass 1 and inner glass 3 and the HIC of the front windshield 200. The heating and softening step involves using a heating element to raise the temperature of the flat glass to a softening temperature. The bending and forming step involves bending the flat glass using a bending mold, which may include at least one of a solid male mold, a solid female mold, an annular male mold, and an annular female mold. The annealing step involves using a blowing device to lower the temperature of the curved outer glass 1 and inner glass 3 to room temperature.

[0087] In the present application, it is preferred that the heating and softening step, the bending and forming step, and the annealing step meet at least one of the following conditions:

[0088] (1) The heating temperature in the heating and softening step is 660°C to 750°C.

[0089] (2) The heating and softening step uses a convection heating method to soften the flat glass.

[0090] (3) The heating and softening step uses a convection heating method and a radiation heating method to soften the flat glass.

[0091] (4) In the heating and softening step, the surface of the flat glass having a lower tin oxide concentration faces the heating element.

[0092] (5) In the heating and softening step, the heating and softening time of the outer glass 1 is greater than the heating and softening time of the inner glass 3.

[0093] (6) In the bending step, the temperature of the bending mold for bending the flat glass is greater than or equal to 500°C.

[0094] (7) In the annealing step, the blowing pressure of the outer glass 1 is lower than the blowing pressure of the inner glass 3 .

[0095] (8) In the annealing step, the annealing time of the outer glass 1 is greater than the annealing time of the inner glass 3.

[0096] Examples 1-18 and Comparative Examples 1-6

[0097] A plurality of float glasses with thicknesses of 2.1 mm and 1.8 mm were prepared, and subjected to a heating and softening step, a bending and forming step, and an annealing step to obtain a curved outer glass 1 and an inner glass 3. The outer glass 1 had a thickness of 2.1 mm, and the inner glass 3 had a thickness of 1.8 mm. A 0.76 mm thick PVB was used as a thermoplastic interlayer 2. The thermoplastic interlayer 2 was laminated with the curved outer glass 1 and the inner glass 3 according to the manufacturing method described in the present application to form a laminated glass structure. The laminated glass structure was heated, vacuumed, and / or pressurized to obtain the front windshield 200 of Examples 1-18 and Comparative Examples 1-6.

[0098] The front windshield 200 of Comparative Examples 1-2 has been weakened and optimized, and has a first weakened area 203, but V2-V1 is less than 0.3 m / s; the front windshield 200 of Comparative Examples 3-4 has been weakened and optimized, and has a first weakened area 203, but V2-V1 is greater than 2.2 m / s; the front windshield 200 of Comparative Examples 5-6 has not been weakened and optimized, and does not have a first weakened area 203. The front windshield 200 of Example 1-18 has been weakened and optimized, and has a first weakened area 203, and satisfies 0.3 m / s≤V2-V1≤2.2 m / s.

[0099] The front windshields 200 of Examples 1-18 and Comparative Examples 1-6 were tested using an adult headform impactor according to standard GB24550. The adult headform impactor was used to impact the first weakened area 203 to rupture the first weakened area 203. After the first weakened area 203 ruptured, the adult headform impactor was used to impact the instrument panel 100. An acceleration sensor and a data acquisition device were used to obtain an impact curve regarding the impact time and the resultant acceleration. The cracking phenomenon of the front windshield 200 was observed or calculated, and the test results are recorded in Table 1.

[0100] Atypical rupture: with at least one of the phenomena (1)-(2);

[0101] (1) When an adult head impactor impacts the first weakened area, the integrity of the front windshield remains unchanged for more than 1ms;

[0102] (2) The first maximum resultant acceleration a5 is greater than 180g during the period from 0 to 5ms in the shock curve;

[0103] Typical rupture: 100≤HIC1≤650 and HIC2<1000, and there is no atypical rupture.

[0104] Table 1: Test results of the front windshield 200 of Examples 1-18 and Comparative Examples 1-6

[0105] Table 1 shows that for Comparative Examples 1 and 2, V2-V1 was less than 0.3 m / s, and the first maximum resultant acceleration a5 was less than 50 g, resulting in HIC1 values ​​less than 100. The front windshield 200 was completely penetrated during the test, resulting in HIC2 values ​​greater than 1000. While the windshield 200 caused minimal primary head injury to the pedestrian, the instrument panel caused severe secondary head injury. For Comparative Examples 3-6, V2-V1 was greater than 2.2 m / s, resulting in HIC1 values ​​greater than 850, or even greater than 1000. The windshield 200 suffered minor cracking during the test, and while HIC2 values ​​were relatively low, they still caused severe primary head injury to the pedestrian.

[0106] The V2-V1 of Example 1-18 satisfies 0.3m / s≤V2-V1≤2.2m / s, preferably 0.6m / s≤V2-V1≤2.0m / s, and more preferably 0.8m / s≤V2-V1≤1.81m / s, which can cause the outer glass 1 and the inner glass 3 of the front windshield 200 to break simultaneously or almost simultaneously after being impacted, and the specific rupture time is shortened to within 3ms, so that the first weakened zone 203 of the front windshield 200 satisfies 100≤HIC1≤650 and HIC2<1000, and there is no atypical rupture phenomenon, which is more conducive to reducing the primary damage caused by the front windshield 200 to the pedestrian's head. On the basis of meeting the basic requirements of protecting the safety of people in the car, it can also reduce the primary damage caused by the front windshield 200 to the pedestrian's head and reduce the secondary damage caused by the dashboard to the pedestrian's head, and ultimately reduce the overall damage suffered by the pedestrian when colliding with the front windshield 200. Among them, the first maximum composite acceleration a5 satisfies 50g≤a5<180g, preferably satisfies 80g≤a5≤170g, and more preferably satisfies 100g≤a5≤150g, which is beneficial to reduce both the primary damage caused by the front windshield 200 to the pedestrian's head and the secondary damage caused by the instrument panel to the pedestrian's head, thereby greatly reducing the total damage value to the pedestrian's head.

[0107] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0108] The above-described embodiments merely represent several implementation methods of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that a person of ordinary skill in the art may make a number of variations and improvements without departing from the concept of the present application, and these variations and improvements fall within the scope of protection of the present application. Therefore, the scope of protection of the patent application shall be based on the appended claims, and the description and drawings may be used to interpret the content of the claims.

Claims

1. A front windshield installed on a vehicle including an instrument panel, the front windshield comprising: The outer layer of glass has a first surface and a second surface disposed opposite to each other; The inner glass has a third surface and a fourth surface which are arranged opposite to each other; and a thermoplastic intermediate layer sandwiched between the second surface and the third surface; The front windshield has a first weakened area, and the first weakened area is tested by using an adult head-shaped impactor, the adult head-shaped impactor impacts the first weakened area to break the first weakened area, and the adult head-shaped impactor impacts the instrument panel after the first weakened area breaks; The adult head-shaped impactor has a first speed V1 when contacting the first surface of the first weakened zone, and has a second speed V2 when the fourth surface of the first weakened zone is broken, and V1 and V2 satisfy: V1=11.1±0.2m / s, V1-V2=0.3~2.2m / s.

2. The front windshield according to claim 1, wherein: V1-V2=0.6m / s~2.0m / s.

3. The front windshield according to claim 1, wherein: The adult head-shaped impactor has a first maximum synthetic acceleration a5 within 0 to 5 ms after impacting the first weakened area, and a5 is less than or equal to 180 g.

4. The front windshield according to claim 1, wherein: The adult head impactor has a first head injury index HIC1 within 0 to 5 ms after impacting the first weakened area and a second head injury index HIC2 within 5 to 15 ms, 100≤HIC1≤650, HIC2<1000.

5. The front windshield according to claim 4, wherein: The front windshield also has a second weakened area, and the second weakened area is tested using an adult head-shaped impactor. The adult head-shaped impactor has a third head injury index HIC3 within 0 to 15 ms after impacting the second weakened area, and HIC3 is less than 1000.

6. The front windshield according to claim 5, wherein: The front windshield includes a transparent area and a shielding area surrounded by the transparent area, the visible light transmittance of the transparent area is greater than or equal to 70%, the visible light transmittance of the shielding area is less than or equal to 10%, and the first weakened area and the second weakened area are both located in the transparent area.

7. The front windshield according to claim 6, wherein: The shielding area includes a top shielding area, a left shielding area, a bottom shielding area and a right shielding area; The distance between the lower boundary of the first weakened area and the bottom shielding area is x, and the distance between the left boundary of the first weakened area and the bottom shielding area is x. The distance between the left shielding area is m, the distance between the right boundary of the first weakened area and the right shielding area is n, the distance between the upper boundary and the lower boundary of the first weakened area is h, x is less than or equal to 15 mm, m is less than or equal to 50 mm, n is less than or equal to 50 mm, and h is equal to 100 mm to 300 mm; The distance between the upper boundary of the second weakened zone and the top shielding zone is y, the distance between the left boundary of the second weakened zone and the left shielding zone is equal to m, the distance between the right boundary of the second weakened zone and the right shielding zone is equal to n, and y is less than or equal to 100 mm.

8. The front windshield according to claim 7, wherein: A transition weakened zone is set between the lower boundary of the second weakened zone and the upper boundary of the first weakened zone, and the area of ​​the transition weakened zone is smaller than the area of ​​the first weakened zone. The transition weakened zone is tested using an adult head-shaped impactor. The adult head-shaped impactor has a fourth head injury index HIC4 within 0 to 15 ms after impacting the transition weakened zone, and HIC4 is greater than HIC1, and HIC4 is less than HIC3.

9. The front windshield according to claim 6, wherein: The ratio of the area of ​​the first weakened zone to the area of ​​the transparent zone is less than or equal to 1 / 3, the ratio of the area of ​​the second weakened zone to the area of ​​the transparent zone is less than or equal to 2 / 3, and the area of ​​the first weakened zone is smaller than the area of ​​the second weakened zone.

10. The front windshield according to claim 1, wherein: The time it takes for the adult head-shaped impactor to impact the first weakened area and cause the first weakened area to rupture is less than or equal to 3 ms.

11. The front windshield according to any one of claims 1 to 10, wherein: The bending strength of the third surface is greater than the bending strength of the second surface, and / or the bending strength of the fourth surface is greater than the bending strength of the second surface.

12. The front windshield according to any one of claims 1 to 10, wherein: The thickness of the thermoplastic intermediate layer located in the first weakened zone is 0.38 mm to 0.6 mm.

13. The front windshield according to any one of claims 1 to 10, wherein: The moisture content of the thermoplastic intermediate layer is 0.3%-0.4% or 0.6%-0.7%.

14. The front windshield according to any one of claims 1 to 10, wherein: The concentration of tin oxide on the second surface is greater than the concentration of tin oxide on the first surface, and the concentration of tin oxide on the third surface is greater than the concentration of tin oxide on the fourth surface; Alternatively, the concentration of tin oxide on the second surface is lower than the concentration of tin oxide on the first surface, and the concentration of tin oxide on the third surface is lower than the concentration of tin oxide on the fourth surface.

15. The front windshield according to any one of claims 1 to 10, wherein: The ratio of the thickness of the outer layer of glass to the thickness of the inner layer of glass is greater than or equal to 0.75 and less than 1.

16. The front windshield according to any one of claims 1 to 10, wherein: A weakened coating is further provided on at least one of the second surface, the third surface and the fourth surface, and the weakened coating at least covers the first weakened area.

17. A method for manufacturing a front windshield according to any one of claims 1 to 16, comprising the following steps: Step 1, providing a curved outer layer of glass and an inner layer of glass, wherein the outer layer of glass has a first surface and a second surface opposite to each other, and the inner layer of glass has a third surface and a fourth surface opposite to each other; Step 2, providing a thermoplastic intermediate layer, and sequentially laminating the outer glass, the thermoplastic intermediate layer and the inner glass to form a laminated glass structure; Step 3: heating, evacuating and / or applying pressure to the laminated glass structure to obtain the front windshield, wherein the front windshield has the first weakened area.

18. The method for manufacturing a front windshield according to claim 17, wherein: The front windshield has at least one weakening structure, the weakening structure is at least located in the first weakening area, and the weakening structure is formed by at least one of the following weakening methods: (1) introducing an internal defect between the first surface and the second surface by using a laser weakening method; (2) introducing an internal defect between the third surface and the fourth surface by using a laser weakening method; (3) forming microcracks on the second surface by a physical friction weakening method; (4) A chemical etching weakening method is used to form fracture lines on the second surface.

19. The method for manufacturing a front windshield according to claim 17, wherein: The bent outer glass and inner glass are obtained by subjecting the flat glass to a heating and softening step, a bending and forming step, and an annealing step, wherein the heating and softening step, the bending and forming step, and the annealing step satisfy at least one of the following conditions: (1) The heating temperature of the heating and softening step is 660° C. to 750° C.; (2) the heating and softening step uses a convection heating method to soften the flat glass; (3) The heating and softening step uses a convection heating method and a radiation heating method to soften the flat glass; (4) in the heating and softening step, the surface of the flat glass having a lower tin oxide concentration faces the heating element; (5) In the heating and softening step, the heating and softening time of the outer layer of glass is greater than the heating and softening time of the inner layer of glass; (6) In the bending step, the temperature of the bending mold for bending the flat glass is greater than or equal to 500° C.; (7) In the annealing step, the blowing pressure of the outer glass is lower than the blowing pressure of the inner glass; (8) In the annealing step, the annealing time of the outer layer of glass is greater than the annealing time of the inner layer of glass.

20. A vehicle, comprising an instrument panel and a front windshield according to any one of claims 1 to 16, wherein the instrument panel is arranged at a lower side close to the front windshield.

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