Symmetrical bending
阅读说明:本技术 对称弯曲 (Symmetrical bending ) 是由 C.马楚拉 于 2019-04-26 设计创作,主要内容包括:本发明涉及通过重力在铰接骨架上弯曲玻璃板。本发明还涉及一种弯曲装置,以及一种作为实施这种弯曲方法的结果而获得的经弯曲的玻璃板。(The present invention relates to bending glass sheets by gravity on an articulated framework. The invention also relates to a bending device and to a bent glass sheet obtained as a result of the implementation of such a bending method.)
1. A device (1) for the gravity bending of at least one glass sheet (2), comprising a support (3), on which support (3) an articulated frame (4) is mounted, suitable for acting as a support at the periphery of said glass sheet (2), said articulated frame (4) comprising two lateral portions (5) arranged on either side of a central portion (6), each lateral portion (5) being connected to the central portion (6) by means of a set of free pivots (11), said articulated frame (4) being supported by said support (3) and being suitable for autonomous movement between:
-a so-called assembly position, in which the two lateral portions (5) are folded down so that the articulated frame (4) forms a planar point support for receiving the glass panel (2), and
-a so-called nominal position, in which the two lateral portions (5) stand on a higher level than the central portion (6), so that the articulated frame (4) reproduces the periphery of the desired curved window at the end of the bending process,
the device (1) is characterized in that it comprises a synchronization system (7) for synchronizing the two lateral portions (5) with each other.
2. Device (1) according to claim 1, characterized in that said synchronization system (7) comprises guide means (7) for guiding said central portion (6) in a substantially vertical direction.
3. Device (1) according to claim 2, characterized in that the guiding means (7) is a foldable cross (7).
4. Device (1) according to any one of claims 1 to 3, characterized in that each lateral portion (5) is connected to the support (3) by means of a set of free pivots or ball joints.
5. Device (1) according to any one of claims 1 to 4, characterized in that it comprises at least one stop (9) for receiving the articulated frame (4) in the nominal position.
6. Device (1) according to any one of claims 1 to 5, characterized in that each lateral portion (5) is connected to a counterweight that assists the movement of the articulated frame (4) from its assembled position to its nominal position.
7. A bending method (S) for bending at least one glass sheet (2) by gravity, said method using a device (1) comprising a support (3), on which support (3) is mounted an articulated frame (4) suitable for acting as a support at the periphery of said glass sheet (2), said articulated frame (4) comprising two lateral portions (5) arranged on either side of a central portion (6), each lateral portion (5) being connected to the central portion (6) by a set of free pivots (11), said device (1) comprising a synchronization system (7) for mutually synchronizing the two lateral portions (5), said articulated frame (4) being supported by the support (3) and being suitable for autonomous movement between:
-a so-called assembly position, in which the two lateral portions (5) are folded down so that the articulated frame (4) forms a planar point support for receiving the glass panel (2), and
-a so-called nominal position, in which the two lateral portions (5) stand on a horizontal plane higher than the lateral ends of the central portion (6),
the bending method (S) comprises at least the following steps:
-placing (S1) the glass panel (2) on the articulated frame (4) in the assembled position,
-bringing (S2) the glass sheet (2) to its softening temperature,
-during the glass softening process, the articulated frame (4) is moved (S3) from the assembly position to the nominal position by a perfectly vertical relative displacement of the central portion (6) with respect to the lateral portions (5).
8. The method of claim 7, wherein a plurality of glass sheets are stacked and bent simultaneously.
9. A bent glass sheet (2) obtained by carrying out the method of any one of claims 7 and 8.
10. Use of a glass pane (2) according to claim 9 as a windscreen and/or rear window of a motor vehicle.
Technical Field
The present invention relates to bending glass sheets by gravity on an articulated framework. In this case, the term "bending" refers to a method of bending a glass sheet with heat. The invention also relates to a bending device and to a bent glass sheet obtained as a result of the implementation of such a bending method.
The glass sheet obtained using this bending method can be used for being arranged on a vehicle, in particular a motor vehicle, and integrated into, for example, a windshield or a rear window.
Background
Gravity bending of glass sheets is well known. Such bending can be produced on a simple support of the frame or skeleton type, the geometry of which does not change during the bending process. Such a frame may optionally be continuous.
It should be noted, however, that automobile manufacturers and designers are increasingly trying to achieve large, complex shapes for modern windows. The purpose of these trends is, inter alia, to enlarge the field of view of the vehicle interior. They also cause a significant increase in the brightness in the passenger compartment and thus create a feeling of spaciousness.
Forming these windows to include both large dimensions and high curvature presents new problems and new technologies are therefore needed. One technical problem arises in particular in the production of panoramic windows, i.e. windows comprising lateral portions bent inwards to a high degree with respect to the central portion of these windows. This difficulty is due in particular to the fact that, over the entire height of the window, at a distance from the edge, a small-radius curved portion is obtained, which is also coupled with a second curved portion lateral with respect to the small-radius curved portion. The combination of these curved portions requires special care to avoid unacceptable deformation.
In order to obtain such windows, it is known to effect bending on a support, the geometry of which varies during the bending process.
Thus, and as shown in fig. 1, it is known to use a
Such an articulated
The articulated
a so-called assembly position, in which the two
A so-called nominal position, in which the two
In other words, the articulated
It should be noted that the position of the lateral portions is described relative to the position of the central portion. Thus, the relative raising of the lateral portions during the change from the fitting position to the nominal position can take three different forms, namely:
only the central portion descends and the lateral portions remain at their original level;
-erecting the lateral portions, the central portion remaining fixed;
the lowering of the central portion is combined with the raising of the lateral portions.
In practice, the
At the beginning of the bending process, the articulated
The first of these zones is a preheating zone in which the glass sheet is heated to a glass temperature substantially near the softening point.
The next zone is the bending zone where the glass sheets, having a temperature up to about 600 c, will gradually bend due to gravity to match the shape of the articulated
The displacement of the various moving elements of the frame represents a change in the shape of the contact surface of the
The movement of the
When the
Once bent, the
It should be noted that although the
In this technique, it is understood that the movement of the
In this case, it has been observed that in the case of asymmetrical heating of the
Disclosure of Invention
The invention makes it possible to overcome this drawback. More specifically, in at least one embodiment, the proposed technology relates to a device for the gravity bending of at least one glass sheet, comprising a support on which is mounted an articulated frame suitable for acting as a support at the periphery of said glass sheet, said articulated frame comprising two lateral portions arranged on either side of a central portion, each lateral portion being connected to the central portion by a set of free pivots, said articulated frame being supported by the support and being suitable for autonomous movement between:
a so-called assembly position in which the two lateral portions are folded down so that the articulated frame forms a planar point support for receiving the glass panel, an
A so-called nominal position, in which the two lateral portions stand on a higher level than the central portion, so that the hinged frame reproduces the periphery of the desired curved window at the end of the bending process,
said device is characterized in that it comprises a synchronization system for synchronizing the two lateral portions with each other.
In this case, the invention is based on a novel and inventive concept of synchronizing two lateral portions of an articulated frame on either side of a central portion. In other words, this includes equalizing its displacement speed and matching its phase.
Thus, if during bending the relative speed at which one of the lateral portions stands up is small, the device slows down and/or stops itself, taking into account that the temperature of the glass sheet portion covering that lateral portion is too low, and only continues to travel when the glass has sufficient ductility on both sides of the central portion.
The result of implementing such a synchronization system is to maintain the central portion in a horizontal orientation throughout the bending process. Thus, the practice of the invention makes it possible to reduce the forming defects of the glass sheet and to improve the performance and repeatability of the bending process.
According to a particular embodiment, the synchronization system comprises guiding means for guiding the central portion in a substantially vertical direction.
Thus, such a guiding means allows a lateral/horizontal fixation of the central portion so that it does not become deflected. The central portion is then translated vertically.
The complete vertical displacement of the central part makes it possible to synchronize the movements of the two lateral parts by means of free pivot sets connecting the central part of the frame to the lateral parts.
According to a particular embodiment, the guiding means is a foldable spider.
In this context, the term "spider" refers to a mechanical system having a deformable parallelogram in the form of a foldable spider, comprising at least two shafts, the central portions of which pivot relative to each other, each shaft sharing a pivot joint at a first end and a sliding pivot joint at a second end. Such a system allows the central portion to be laterally fixed without hindering its vertical displacement. Thus, the central portion maintains the same lateral position throughout the bending process, regardless of its height.
According to a particular embodiment, each lateral portion is connected to the support by a set of free pivots or a set of ball joints.
According to a particular embodiment, the device comprises at least one stop for receiving the articulated frame in the nominal position.
Such a stop, which acts as a support for the articulated frame in the nominal position, makes it possible to relieve the articulated frame from the stresses associated with the weight of the glass sheet and the weight of the frame.
According to a particular embodiment, each lateral portion is connected to a counterweight that assists the movement of the articulated frame from its assembled position to its nominal position.
Although the implementation of these counterweights is not necessary to solve the general problem of the invention, the counterweights, in combination with the weight of the articulated
The invention also relates to a bending method for bending at least one glass sheet by gravity, using a device comprising a support on which is mounted an articulated frame suitable for acting as a support at the periphery of said glass sheet, said articulated frame comprising two lateral portions arranged on either side of a central portion, each lateral portion being connected to the central portion by a set of free pivots, said device comprising a synchronization system for mutually synchronizing the two lateral portions, said articulated frame being supported by the support and being suitable for autonomous movement between:
a so-called assembly position in which the two lateral portions are folded down so that the articulated frame forms a planar point support for receiving the glass panel, an
A so-called nominal position, in which the two lateral portions stand on a horizontal plane higher than the lateral ends of the central portion,
the bending method comprises at least the following steps:
-placing the glass panel on the articulated frame in the assembled position,
bringing the glass sheet to its softening temperature,
during the glass softening process, the articulated frame is moved from the fitting position to the nominal position by a relative, purely vertical displacement of the central portion with respect to the lateral portions.
According to a specific embodiment, several glass sheets are stacked and bent simultaneously.
The invention also relates to a bent glass sheet obtained by implementing the above method.
The invention also relates to the use of such a glass pane as a windscreen and/or rear window of a motor vehicle.
Drawings
Other characteristics and advantages of the invention will appear on reading the following description of specific embodiments, given as a simple illustrative and non-limiting example and with reference to the accompanying drawings, in which:
figure 1 is a schematic lateral view of a known bending device in an assembled position,
figure 2 is a schematic lateral view of the known bending device in the nominal position,
figure 3 is a lateral schematic view of a known bending device during asymmetric bending,
figure 4 is a schematic side view of a bending device according to a first particular embodiment of the invention,
figure 5 is a schematic side view of a bending device according to a second particular embodiment of the invention,
fig. 6 is a flow chart illustrating the steps for implementing the bending method according to a specific embodiment of the invention.
Detailed Description
The various elements shown in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the general operation of the invention. In this case, the same reference numerals denote similar or identical elements, unless otherwise specified.
Several specific embodiments of the present invention are given below. It is to be understood that the invention is in no way limited to specific embodiments and that other embodiments may well be practiced.
As shown in fig. 4, the
Such an articulated
According to a second embodiment, shown in figure 5, the articulated
The
a so-called assembly position, in which the two
A so-called nominal position, in which the
It should be noted that according to both embodiments of the invention, the articulated
As shown in fig. 4 and 5, the
Furthermore, the two
The result of implementing such a synchronization system is that the
As shown in fig. 6, a bending method according to an embodiment of the present invention includes the steps of:
placing (step S1) the
bringing (step S2) the
during the glass softening process, the articulated
Once bent, the
According to a specific embodiment of the present invention, a plurality of