Production system and method for the high-temperature re-forming of glass blanks for producing optical lenses

Abstract

The invention relates to a production system (100) for the high-temperature re-forming of glass blanks (130), preferably glass blanks (130) made of quartz glass, in particular for producing optical lenses, comprising a temperature-control chamber (102) for controlling the temperature of the glass blank below a re-forming temperature, through which the glass blanks can be moved in a horizontal feed direction, also comprising a high-temperature chamber (152) having a heating unit (160) for controlling the temperature of the glass blank to a re-forming temperature, which is preferably greater than 1400°C, wherein the temperature-control chamber (102) and the high-temperature chamber (152) are connected to one another in a fluid-tight manner and have a transfer opening (158), through which the glass blanks can be moved, and further comprising a re-forming device (142), which is set up and designed to move the glass blank (130) by a vertical movement from the temperature-control chamber (102) through the transfer opening (158) into the high-temperature chamber (152) and to re-form the glass blank (130) in the high-temperature chamber (152).

Description

[0001] Manufacturing system and method for high-temperature forming of glass blanks for the production of optical lenses

[0002] The invention relates to a manufacturing system and a method for high-temperature forming of glass blanks, preferably quartz glass blanks, in particular for the production of lenses, preferably optical lenses. Manufacturing systems for high-temperature forming of glass blanks are generally known. Glasses with a high forming temperature cannot be formed using conventional forming methods, or can only be formed to a limited extent, because the temperature resistance of the machine technology is insufficient. Furthermore, the cycle time and tool wear can be excessive. Many glasses can be formed at a forming temperature below 800°C.

[0003] However, there is a demand in industry for products made from glasses with a high forming temperature. Examples of such glasses include high-temperature glasses, such as quartz glass and ceramics. The forming temperature of such glasses is typically in the range between 1,400°C and 1,700°C. Due to the high forming temperatures of such glasses, they are not yet manufactured on an industrial scale by forming, but rather using conventional manufacturing processes. For this purpose, a glass blank is subjected to grinding and polishing processes until it has a predetermined shape and predetermined surface properties. The grinding and polishing processes required for this require complex process kinematics, which is complex, among other things, due to the punctual intervention during processing. The machine tools required for this are cost-intensive and the production time is long.In addition, the individual process steps require intermediate cleaning of the glass.

[0004] One approach to hot forming glass blanks involves the use of single-station glass presses, which are used, for example, for precision molding. One such single-station glass press is disclosed in US5938807A.

[0005] When using single-station glass presses, the glass blank is heated to the forming temperature and then formed within a bell jar. The glass blank, the forming tool, and the bell jar are heated externally by radiation and secondarily by convection. Such a bell jar is made from a high-temperature glass. Since the required forming temperatures of the glass blank can reach or exceed the softening temperature of the bell jar, this approach is not suitable for high-temperature forming, for example, of quartz glass. While the use of cooling systems allows for cooling of the bell jar, this cooling is generally not sufficient to prevent softening of the bell jar at forming temperatures well above 1,000°C. A further disadvantage of single-station glass presses is the time-consuming heating and subsequent cooling required.The cycle time of single-station glass presses is therefore in the range of 20 to 30 minutes, for example. Furthermore, energy efficiency is low due to heating and cooling.

[0006] Another approach to hot forming glass blanks involves the use of so-called batch furnaces. These furnaces have a closed heating zone that is thermally isolated from the environment by thermal insulation. The thermal insulation typically consists of thick insulating layers made of ceramics or flint. These furnaces have a high thermal mass, which leads to a long heating and cooling rate. At the same time, this high thermal mass results in good temperature stability of the furnace, allowing the glass produced to be of high quality.

[0007] The heating elements used in such furnaces are typically made of molybdenum, molybdenum disilicide, tungsten, or graphite. Since the heating elements often have to reach temperatures of more than 1,800°C to provide the required heat output, a controlled atmosphere must be created within the furnace. For this reason, the furnace chamber is usually gas-tight. The entire forming process chain is essentially replicated within the batch furnace. First, the glass blank is moved into the cooled batch furnace and, as a next step, tempered there, thus implementing a preheating process. The glass blank is then heated to the forming temperature and formed. The cooling process then takes place in the batch furnace. Both preheating and cooling must take place within the batch furnace, as a glass blank at a high temperature cannot be moved separately, as this would lead to contamination and possibly deformation.

[0008] Due to the high thermal mass of such a furnace, preheating and cooling lead to a long forming process. The entire forming process typically takes several hours. Despite intensive research, the cycle time has not been significantly reduced. Furthermore, contamination of the forming tools and tool wear are detrimental. A batch furnace is therefore unsuitable for the industrial-scale production of formed glass blanks, especially optical lenses.

[0009] One approach to forming glass blanks at a lower temperature, for example 800°C, is the use of so-called transfer machines, as described, for example, in German patent application 10 2022 130 329.2. However, transfer machines are generally not suitable for

[0010] Suitable for providing high temperatures in the range of over 1,000°C.

[0011] It is therefore an object of the invention to provide a manufacturing system and a method for high-temperature forming of glass blanks that reduce or eliminate one or more of the aforementioned disadvantages. In particular, it is an object of the invention to enable high-temperature forming of glass blanks on an industrial scale.

[0012] This object is achieved with a manufacturing system and a method according to the features of the independent patent claims. Further advantageous embodiments of these aspects are specified in the respective dependent patent claims. The features disclosed in the patent claims, the description, and the drawings can be combined individually in any technologically expedient manner, with further embodiments of the invention being shown.

[0013] According to a first aspect, the object mentioned at the outset is achieved by a production system for the high-temperature forming of glass blanks, preferably glass blanks made of quartz glass, in particular for the production of lenses, preferably optical lenses, comprising a temperature control chamber for tempering the glass blank below a forming temperature, through which the glass blanks can be moved in a horizontal feed direction, a high-temperature chamber with a heating unit for tempering the glass blank to a forming temperature which is preferably greater than 1,000°C, greater than 1,100°C, greater than 1,200°C, greater than 1,300°C and / or greater than 1.400°C, wherein the tempering chamber and the high-temperature chamber are connected to one another in a fluid-tight manner and have a transfer opening through which the glass blanks can be moved, a forming device which is arranged and designed to move the glass blank from the tempering chamber through the transfer opening into the high-temperature chamber with a vertical movement and to form the glass blank in the high-temperature chamber.

[0014] The invention is based on the finding that a further optimization of batch furnaces with regard to their cycle time and a further optimization of transfer machines with regard to the maximum forming temperature is not effective.

[0015] The invention was further based on the discovery that a clever combination of transfer machine and batch furnace approaches makes high-temperature forming of glass blanks possible on an industrial scale. Within the tempering chamber, in the manner of a transfer machine, efficient preheating of the glass blank and efficient cooling of the formed glass blank are possible. By cleverly coupling the tempering chamber with a high-temperature chamber, in which the glass blanks are heated to the high forming temperature and also formed there, the cycle time can be reduced significantly. The inventors discovered that the glass blank only needs to remain within the high-temperature chamber for a few minutes for tempering and forming. This allows the cycle time to be reduced from several hours to just a few minutes.

[0016] The manufacturing system is designed for high-temperature forming of glass blanks. High-temperature forming is characterized in particular by forming temperatures well above 1,000°C, especially in the range of more than 1,400°C. The glass blanks are, in particular, made of a glass material that requires such a high forming temperature, such as quartz glass or a ceramic material.

[0017] The manufacturing system comprises the tempering chamber for tempering the glass blank below the forming temperature of the glass blank. The glass blanks can be moved through the tempering chamber in a horizontal feed direction. The tempering chamber preferably has one, two, or more preheating stations. Furthermore, it is preferred that the tempering chamber has one, two, or more cooling stations. In the context of glass forming, a cooling station is understood in particular to mean that, although it cools the glass to a lower temperature, it also has heating elements. The preheating and / or cooling stations can, in particular, have heating cartridges, which are operated electrically, for example. The tempering chamber is, in particular, arranged and designed to temper the glass blanks to a temperature of up to 800°C, preferably up to 1,000°C. The tempering chamber can have insulation known from transfer machines.The temperature control chamber is, in particular, designed to be substantially fluid-tight. The temperature control chamber preferably comprises an inlet lock for loading the production system with glass blanks and / or an outlet lock for removing the formed glass blanks from the production system. The formed glass blanks are, in particular, glass products, for example, optical lenses.

[0018] The tempering chamber preferably has transfer means arranged and designed to move the glass blanks in the horizontal feed direction. In particular, the transfer means are arranged and designed to discontinuously move pressing tools from one station to the next station, wherein the pressing tools contain at least one glass blank. A horizontal feed direction is understood, for example, to be a direction that is ideally horizontal and / or inclined to a horizontal, for example inclined by + / - 30°, in particular + / - 20°, further preferably + / - 10°, relative to the horizontal. The inclined horizontal feed direction can, for example, be stepped, wherein a subsequent station is arranged slightly lower than a preceding station, for example less than 10 mm lower.

[0019] The manufacturing system further comprises the high-temperature chamber with the heating unit. The high-temperature chamber and the heating unit are arranged and designed to temper the glass blank to the forming temperature, wherein this forming temperature is in particular more than 1,400°C. The heating unit is therefore in particular arranged and designed to enable such tempering. For this purpose, the heating unit generally comprises heating elements that can be tempered to a higher temperature than the forming temperature so that the glass blank itself can be tempered to the forming temperature. The high-temperature chamber is in particular arranged and designed to be accessible during ongoing operation of the manufacturing system, in particular at a temperature of more than 1,400°C. The heating unit preferably comprises graphite, tungsten, molybdenum and / or molybdenum disilicide, in particular heating elements made of or containing these materials.The heating unit can also be designed to be inductive. The high-temperature chamber is preferably fluid-tight, allowing a predefined atmosphere to be created within the high-temperature chamber. This is particularly necessary, taking into account the temperatures prevailing in the high-temperature chamber, to avoid or reduce unwanted chemical reactions, particularly in the heating unit.

[0020] The high-temperature chamber and the tempering chamber are connected in a fluid-tight manner. This ensures that the high-temperature chamber is not damaged by oxidation, particularly by oxygen ignition, and that the glass blank is not contaminated when the glass blank is moved from the tempering chamber to the high-temperature chamber.

[0021] In particular, it is preferred that the fluid-tight connection between the temperature control chamber and the high-temperature chamber be provided outside of any thermal insulation of the high-temperature chamber and / or the temperature control chamber, so that the fluid-tight seal is exposed to lower temperatures. Thus, conventional sealing elements, for example, designed for temperatures between 20°C and 500°C, can be used.

[0022] The transfer opening, through which the glass blanks can be moved, is located between the tempering chamber and the high-temperature chamber. In particular, the transfer opening is dimensioned such that pressing tools can be moved through it.

[0023] The manufacturing system further comprises the forming device, which is arranged and configured to move the glass blank from the tempering chamber through the transfer opening into the high-temperature chamber with a vertical movement. For this purpose, the forming device can, for example, have a lower punch whose arrangement surface is located essentially on the same plane as the arrangement surfaces of the stations in the tempering chamber, at least in an initial situation. After the glass blank has been arranged, in particular with a pressing tool, on the arrangement surface of the forming device or punch, it can be moved upwards in a vertical direction and thus moved through the transfer opening into the high-temperature chamber.

[0024] Furthermore, the forming device is arranged and configured to form the glass blank in the high-temperature chamber. This forming takes place, in particular, after the glass blank has been tempered to the forming temperature, in particular more than 1,400°C. The forming device is arranged and configured, in particular, to move the glass blank back into the tempering chamber with a vertical movement after the forming process.

[0025] The vertical movement can ideally be vertical or inclined to a vertical line. This inclination can be, for example, + / - 30°, + / - 20°, or + / - 10°. In particular, a vertical movement is understood to mean a movement that encloses an angle with the horizontal feed direction, in particular a 90° angle. This ensures that the glass blank is temporarily separated from the main movement of the glass blanks in the tempering chamber into the high-temperature chamber. Depending on the orientation of the entire production system, the vertical movement can also be horizontal, but encloses an angle of, for example, 90° with the horizontal feed direction.

[0026] It is particularly preferred that the forming device has a pressing axis and the vertical movement is aligned parallel, in particular coaxially, with the pressing axis.

[0027] It is particularly preferred that the glass blank is arranged within a pressing tool and that the glass blank is moved with the pressing tool through the tempering chamber, into the high-temperature chamber and formed in the high-temperature chamber.

[0028] In a preferred embodiment of the production system, it is provided that the glass blank is movable with a main movement from an inlet to an outlet through the tempering chamber, the tempering chamber has a preheating section adjacent to the inlet, a cooling section adjacent to the outlet and a transfer section provided between the preheating section and the cooling section, and the forming device is arranged and designed to move the glass blank from the transfer section into the high-temperature chamber.

[0029] The preheating section and the cooling section preferably each have at least one preheating station and one cooling station. At these stations, the glass blank is arranged on an arrangement surface, in particular by means of the pressing tool. Preferably, the forming device in the transfer section also has an arrangement surface. In particular, these surfaces are arranged in one plane.

[0030] The main movement with which the glass blanks are moved through the tempering chamber is preferably discontinuous. With the discontinuous main movement, for example, the glass blank is first transferred to a first preheating station, remains there for a predetermined period of time, and is then transferred to the next station, such as the transfer section. From there, the glass blank is moved into the high-temperature chamber, where it is further tempered, formed, and moved back to the transfer section and transferred to the subsequent cooling station. These processes are preferably synchronized so that a discontinuous main movement can be determined for all glass blanks arranged within the production system.

[0031] The inlet lock mentioned above is located specifically at the inlet. The outlet lock mentioned above is located specifically at the outlet. In contrast to the batch furnaces described above, the arrangement of the glass blanks in the tempering chamber is significantly simpler than in high-temperature chambers, since the temperature here is many times lower.

[0032] The preheating section preferably has one, two or more preheating stations, which further preferably have heating blocks with heating cartridges. Thus, sequential temperature control takes place, with the temperature increasing from station to station. The cooling section preferably has one, two or more cooling stations, which further preferably have heating blocks with heating cartridges. With more than one cooling station, the temperature decreases from station to station. In a further preferred embodiment of the production system, it is provided that the transfer section is thermally decoupled from the preheating section and / or the cooling section, such that heat transfer from the high-temperature chamber and / or the transfer section to the preheating section and / or the cooling section is reduced.

[0033] The thermal decoupling of the transfer section from the preheating section and / or the cooling section can be achieved, in particular, by means of a lock, in particular a convection lock. Since heat transfer from the high-temperature chamber to the tempering chamber occurs during the movement of the glass blank between the tempering chamber and the high-temperature chamber, it is preferable to thermally decouple the transfer section provided below the high-temperature chamber from the preheating section and the cooling section, so that heat does not reach the preheating section and the cooling section. This increases the energy efficiency of the production system, and the preheating section and the cooling section enable defined temperature control.

[0034] A preferred development of the production system is further characterized in that the high-temperature chamber is arranged vertically above the tempering chamber and preferably vertically above the transfer section, and the tempering chamber and the high-temperature chamber are mounted to one another in a floating manner, in particular in the horizontal direction.

[0035] Due to the high temperatures of the high-temperature chamber and the temperature control chamber, thermally induced expansion is to be expected. The high-temperature chamber, in particular, will exhibit thermal expansion in the range of more than 1 cm with regard to the high-temperature elements, such as the thermal insulation. Floating mounting of the temperature control chamber and the high-temperature chamber can thus further lead to good insulation and, in particular, fluid tightness. The floating mounting prevents damage to the components due to thermal expansion. A further preferred embodiment of the production system is characterized in that the forming device is arranged and designed to partially close the transfer opening during the vertical movement, so that a gap is formed between the chambers to compensate for thermal expansion and / or to reduce heat loss.

[0036] Such a forming device reduces heat transfer through the gap between the high-temperature chamber and the tempering chamber. This enables a more constant and / or homogeneous temperature distribution in the high-temperature chamber. At the same time, the remaining gap between the high-temperature chamber and the tempering chamber allows for thermal expansion as well as chemical and physical processes. The gap preferably has a cross-section that is many times smaller than the cross-sectional area of ​​the transfer opening. In order to at least partially close the transfer opening during the vertical movement and in particular during the forming process, the forming device preferably has a collar on the punch and / or shielding plates.

[0037] In a further preferred embodiment of the manufacturing system, it is provided that the high-temperature chamber is surrounded by thermal insulation which is arranged and designed to thermally insulate the high-temperature chamber from an environment, and the thermal insulation is surrounded by a fluid-tight housing which is arranged and designed to reduce or prevent fluid exchange between the high-temperature chamber and the environment.

[0038] The thermal insulation is preferably multi-layered. The layers of the multi-layer insulation are preferably arranged so that they can move relative to one another. It is particularly preferred that the multi-layer insulation be shaded in the area of ​​the transfer opening. The multi-layer insulation preferably does not completely surround the high-temperature chamber in order to keep the transfer opening clear.

[0039] The thermal insulation is designed to prevent or reduce heat transfer from the high-temperature chamber to the surroundings of the high-temperature chamber. To ensure a defined atmosphere in the high-temperature chamber and / or the temperature control chamber, the high-temperature chamber has a fluid-tight housing. The fluid-tight housing is, in particular, designed to be gas-tight. Fluid-tight or gas-tight means, in particular, that they are essentially fluid-tight or gas-tight, respectively, since 100 percent fluid-tightness is not possible at the temperatures prevailing here.

[0040] In a further preferred embodiment of the production system, it is provided that the thermal insulation has an insulation opening on an upper side of the high-temperature chamber, which is arranged and designed to guide the forming device, in particular an upper forming unit, through, wherein the insulation opening is closed with an insulation cover consisting of or comprising insulation material, preferably the same insulation material as the thermal insulation, wherein the insulation cover preferably has an insulation passage which is arranged and designed to guide a punch of the upper forming unit through.

[0041] In a preferred embodiment of the manufacturing system, it is arranged and configured to create a protective gas atmosphere within the temperature control chamber and / or the high-temperature chamber. For this purpose, the temperature control chamber and / or the high-temperature chamber have corresponding locks at the inlets and outlets. The housings of the high-temperature chamber and / or the temperature control chamber are designed to be substantially fluid-tight. Preferably, the temperature control chamber and / or the high-temperature chamber have a protective gas supply. The protective gas can, in particular, be argon.

[0042] A further preferred embodiment of the manufacturing system comprises a protective gas unit arranged and configured to fill the tempering chamber and / or the high-temperature chamber with a protective gas. A protective gas atmosphere created by the protective gas in the tempering chamber and / or the high-temperature chamber has an overpressure, so that fluid ingress from the environment into the tempering chamber and / or the high-temperature chamber is reduced or prevented in order to avoid contamination of the glass blank and to prevent undesired chemical processes in the high-temperature chamber. Oxidation of the heating elements and other components such as the pressing tools must be avoided in particular. Otherwise, graphite, for example, can self-ignite in oxygen above approximately 600°C.

[0043] It is preferred that the manufacturing system has one, two or more pressure relief valves for the controlled discharge of the protective gas, in particular to specifically cool and / or to specifically adjust an overpressure in the tempering chamber and / or the high-temperature chamber. It is preferred that the protective gas unit is arranged and designed to provide a protective gas supply on an upper side of the high-temperature chamber. Furthermore, it is preferred that the pressure relief valve(s) are arranged on an underside of the tempering chamber, in particular of the transfer section. Furthermore, it may be preferred that the protective gas supply is set up by means of the forming device, so that the forming device is additionally cooled by means of the protective gas. Furthermore, the pressing tool and / or the glass blank can thus be cooled if necessary.

[0044] It is further preferred that the upper and / or lower forming unit, described in more detail below, be cooled. This cooling can be achieved, in particular, by means of the protective gas. Since the upper forming unit constantly remains in the high-temperature chamber and the lower forming unit is moved in and out of the high-temperature chamber, separate cooling of the upper and lower forming units may be advisable in order to cool them as required.

[0045] In a further preferred embodiment, the protective gas is preheated, in particular by means of the protective gas unit. Furthermore, the protective gas can be preheated by using the protective gas in the preheating section. Furthermore, the hot protective gas from the high-temperature chamber can be used in the cooling area.

[0046] In a further preferred embodiment, it is provided that the forming device has a lower forming unit and an upper forming unit, the lower forming unit is arranged and designed to carry out the vertical movement, in particular to move the glass blank from the transfer section into the high-temperature chamber.

[0047] It is preferred that the upper forming unit is arranged and configured to perform a second vertical movement which can be oriented opposite to the vertical movement.

[0048] The lower forming unit and the upper forming unit each have distal ends that protrude into the high-temperature chamber or are movable into the high-temperature chamber. At the distal ends, the lower forming unit and / or the upper forming unit has a flange that is particularly arranged and configured to cooperate with a pressing tool. The second vertical movement is preferably directed vertically downward. The second vertical movement is preferably directed vertically upward.

[0049] The upper and lower forming units are particularly arranged and configured such that their pressing axes are aligned parallel, preferably coaxially. The second vertical movement allows the vertical position of the glass blank within the temperature chamber to be changed during forming. Since vertically adjacent temperature zones can be formed in the high-temperature chamber, the temperature can be varied during forming, thereby achieving advantageous physical and / or chemical effects during forming.

[0050] In a further preferred embodiment of the production system, it is provided that the high-temperature chamber and the heating unit are arranged and designed to maintain a constant temperature within the high-temperature chamber during normal operation.

[0051] A constant temperature is understood in particular to mean that there is no deliberate heating up and / or down, for example, to carry out preheating and / or cooling processes. Naturally, the temperature within the high-temperature chamber will fluctuate within certain ranges due to the regular movement of the glass blank in and out.

[0052] A constant temperature is understood, in particular, to be a temperature that remains constant over time. Maintaining a constant temperature within the high-temperature chamber, and in particular avoiding regular heating and cooling cycles, increases the energy efficiency of the production system. A constant temperature can also be achieved in high-temperature chambers that, for example, have two or more temperature layers, as explained below.

[0053] In a further preferred embodiment of the production system, it is provided that the heating unit is arranged and designed to form a temperature profile in the high-temperature chamber, so that the glass blank can be tempered depending on a position in the high-temperature chamber in order to set a predetermined temperature profile in the glass blank by means of an entry speed of the forming device.

[0054] The temperature profile preferably has two or more vertically adjacent temperature layers. In particular, it is preferred that the temperature layer adjacent to the transfer opening has a lower temperature than the temperature layers provided above this temperature layer. Thus, by slowly moving the glass blank into the high-temperature chamber, a lower temperature can initially be applied to the glass blank, while this temperature is increased by further vertical movement into the high-temperature chamber. This allows an initially lower heating rate and / or a lower temperature gradient to be set.

[0055] In a further preferred embodiment of the production system, the heating unit forms two or more heating zones within the high-temperature chamber, wherein the heating zones are formed by separate heating elements. It is preferred that each heating element forms a heating zone. Furthermore, it may be preferred that two or more heating elements form a heating zone.

[0056] It is further preferred that two or more heating zones are formed vertically adjacent to one another. Two or more heating zones, in particular two or more vertically adjacent heating zones, create an advantageous temperature profile in the high-temperature chamber. It is further preferred that the heating elements are arranged offset from one another in the horizontal direction. It is particularly preferred that the heating elements extend further into the high-temperature chamber in an upper region than in a lower region of the high-temperature chamber. Thus, the heating elements radiate less from one another, and wear is reduced.

[0057] In a further preferred embodiment of the manufacturing system, it is provided that it comprises a control unit arranged and configured to control the movement and / or speed and / or forming force of the forming device, wherein the vertical movement is preferably controlled such that the glass blank is tempered according to a predefined temperature curve. The high-temperature chamber preferably has a lower temperature in a lower region, so that by slowly moving it in, heating is initially carried out at a lower temperature than in the middle or upper region.

[0058] In a further preferred embodiment, the control unit is configured to adjust the vertical position of the glass blank during forming according to a predefined movement pattern by controlling the forming device, preferably the upper and lower forming units. Thus, the temperature can be adjusted during forming, thereby achieving positive physical and / or chemical effects.

[0059] In a further preferred embodiment of the manufacturing system, the control unit is configured to control the heating unit such that the temperature within the high-temperature chamber remains constant. A control unit configured in this way may, but need not, have the functions described above for controlling the forming, movement, and / or speed.

[0060] According to a further aspect, the object mentioned at the outset is achieved by a method for the high-temperature forming of glass blanks, preferably glass blanks made of quartz glass, in particular for the production of lenses, preferably with a production system according to one of the embodiments described above, in particular optical lenses, comprising the steps of: tempering the glass blank below a forming temperature within a tempering chamber through which the glass blank is moved in a horizontal feed direction, in particular a discontinuous feed direction, vertically moving the glass blank from the tempering chamber into a high-temperature chamber which is fluid-tightly connected to the tempering chamber and tempering the glass blank to a forming temperature and forming the glass blank within the high-temperature chamber.

[0061] The vertical movement of the glass blank from the tempering chamber into a high-temperature chamber fluid-tightly connected to the tempering chamber occurs, in particular, during a time period in which the other glass blanks within the tempering chamber are not moving. For example, these additional glass blanks can be arranged in a preheating section and / or a cooling section on a preheating station and / or a cooling station.

[0062] In a preferred embodiment of the method, it is provided that it comprises the step or steps: vertically moving the formed glass from the high-temperature chamber into the tempering chamber and preferably horizontally moving the formed glass into a cooling section.

[0063] In a further preferred embodiment of the method, it is provided that it comprises the step or steps: setting a constant temperature within the high-temperature chamber, and / or setting local temperature gradients, in particular along a vertical axis within the high-temperature chamber.

[0064] For further advantages, design variants and details of the individual aspects and their possible further training, please refer to the description of the other aspects, the corresponding features and further training.

[0065] Preferred embodiments are explained by way of example with reference to the accompanying figures. Figures 1 to 3 show schematic, two-dimensional views of an exemplary embodiment of a manufacturing system in various states of the forming device;

[0066] Figures 4 to 9: schematic, two-dimensional views of exemplary embodiments of

[0067] high-temperature chambers;

[0068] Figure 10: a schematic, two-dimensional detailed view of a temperature chamber and a high-temperature chamber; and

[0069] Figure 11 : a schematic view of an exemplary method.

[0070] In the figures, identical or essentially functionally identical or similar elements are designated by the same reference numerals.

[0071] The exemplary embodiments explained below are preferred embodiments of the invention. In the exemplary embodiments, the described components of the embodiments each represent individual, independently considered features of the invention, which also further develop the invention independently of one another and are also to be considered as components of the invention, either individually or in a combination other than that shown. Furthermore, the described embodiments can also be supplemented by further features of the invention already described.

[0072] Figures 1 to 3 show a manufacturing system 100 for high-temperature forming of glass blanks 130, wherein the glass blank 130 consists, for example, of quartz glass.

[0073] The manufacturing system 100 comprises a tempering chamber 102 and a high-temperature chamber 152. The tempering chamber 102 is enclosed by a tempering housing 103. The tempering chamber 102 extends from an inlet 104 to an outlet 106. An inlet lock 108 is provided at the inlet 104, and an outlet lock 110 is provided at the outlet 106, through which the blanks 130 can be moved into and out of the manufacturing system 100. Between the inlet 104 and the outlet 106, the glass blanks 130 are moved with a discontinuous main movement 112. The tempering chamber 102 has a total of five stations. Adjacent to the inlet 104 is a preheating section 114, in which two preheating stations are arranged for preheating the glass blanks 130. The structure of a station is described using preheating station 120 as a representative example of the other stations.

[0074] The heating station 120 has an upper heating unit 122 and a lower heating unit 124, between which a forming tool 128 can be arranged, with the glass blank 130 arranged within the forming tool 128. The heating units 122, 124 have a plurality of electric heating cartridges 126 with which the heating units 122, 124 are heated and can thus heat the forming tool 128 and the glass blank 130.

[0075] Adjacent to the outlet 106 is a cooling section 118 with two cooling stations. A transfer section 116 is provided between the cooling section 118 and the preheating section 114. The transfer section 116 is thermally and / or fluidically separated from the cooling section 118 and the preheating section 114 by locks 140. At each of the five stations, a forming tool 128, 132-138, each with a glass blank 130, is arranged. According to a discontinuous movement, after a certain time, each of the forming tools 128, 132-138 is moved one station further in the main movement direction 112.

[0076] The forming device 142 operates in the transfer section 116. However, in contrast to known devices, no forming takes place within the tempering chamber 102. The forming device 142 has a lower forming unit 144 and an upper forming unit 148. The lower forming unit 144 has a lower forming flange 146 at its distal end, and the upper forming unit 148 has an upper forming flange 150 at its distal end. The lower forming unit 144 is arranged and configured to move the glass blank 130, here with the forming tool 134, from the tempering chamber 102, i.e., here from the transfer section 116, through the transfer opening 158 into the high-temperature chamber 152. This movement occurs with a vertical movement 143. The forming tool 134 arranged on the lower forming flange 146 is moved upwards by the vertical movement 143.The forming tool 134 is thus first moved through the transfer opening 158 and then into the interior 153 of the high-temperature chamber 152.

[0077] Within the high-temperature chamber 152, a significantly higher temperature is reached than in the tempering chamber 102. This is achieved by means of the heating unit 160 and a correspondingly coordinated thermal insulation 156. The heating unit 160 has heating elements 162 designed to enable high-temperature forming within the high-temperature chamber 152. In particular, the glass blank 130 is to be heated in the high-temperature chamber 152 to a temperature of more than 1,400°C.

[0078] The high-temperature chamber 152 is further surrounded by a housing 154, which separates the high-temperature chamber 152 and, in particular, the interior 153 from the environment of the manufacturing system 100. Thus, a defined atmosphere, for example, made of argon, can be established within the temperature control chamber 102 and the high-temperature chamber 152, in particular with a slight overpressure compared to the environment.

[0079] Figure 1 shows the state of the manufacturing system 100 in which the forming tools 128, 132-138 have just been moved from one station to the next. In this state, the lower forming unit 144 is in a lower position in which the forming tool 134 is movable onto the lower forming flange 146. In particular, the surface of the lower forming flange 146 is substantially flush with the other assembly surfaces in the preheating section 114 and the cooling section 118.

[0080] In Figure 2, the vertical movement 143 is performed, whereby the forming tool 134 is moved through the transfer opening 158.

[0081] Figure 3 shows that the forming tool 134 with the glass blank 130 is arranged within the high-temperature chamber 152 or the interior space 153.

[0082] Figure 4 shows that, due to physical effects, vertically adjacent temperature ranges 164, 166, 168, 170 are formed in the interior 153 of the high-temperature chamber 152. As a result, the heating element 162 of the heating unit 160 is generally heated to a higher temperature than the forming temperature of the glass blank 130, which can be achieved in the fourth temperature range 170.

[0083] Figure 5 shows a multi-layer thermal insulation 156. The thermal insulation 156 comprises an outer insulation 172, a middle insulation 174, and an inner insulation 176. The insulations 172, 174, 176 are arranged so as to be movable relative to one another, so that thermal expansion can be compensated. Furthermore, the insulations 172, 174, 176 adjacent to the transfer opening 158 are designed such that the transfer opening 158 widens toward the temperature control chamber 102. For this purpose, the inner insulation 176 forms an inner opening diameter 178, the middle insulation 174 forms a middle opening diameter 180, and the outer insulation 172 forms an outer opening diameter 182. The inner opening diameter 178 is smaller than the middle opening diameter 180, which in turn is smaller than the outer opening diameter 182.

[0084] Figure 6 shows a specific embodiment of the heating unit 160, namely with three heating elements 184, 186, 188 arranged vertically one above the other. Three heating zones arranged one above the other are to be formed with the heating elements 184, 186, 188. For example, it may be preferable for the heating zone created by the heating element 188 to have a lower temperature than the heating zones created by the heating element 186 and the heating element 184. Thus, the tool 134 can move slowly into the high-temperature chamber 152 and is thus exposed to a lower temperature.

[0085] Figure 7 shows that the heating elements 184-188 can be arranged offset from one another in the horizontal direction. The heating element 184 in the upper region faces further toward a central axis of the high-temperature chamber 152 than the lower heating elements 186, 188. Thus, the heating elements 184, 186, 188 are partially shielded from one another, so that their mutual influence is less.

[0086] Figure 8 shows that the housing 154 of the high-temperature chamber 152 is arranged at a distance from the thermal insulation 156 and is further sealed from the temperature control housing 103 by a seal 192. Furthermore, a cooling channel 190 is shown in the housing 154. Figure 9 shows that an insulation opening 194 is provided in the ceiling region of the thermal insulation 156, wherein the insulation opening 194 has a cross-section such that the upper forming flange 150 can be passed through this insulation opening 194. In order to keep thermal losses as low as possible, the insulation opening 194 is essentially closed by means of an insulation cover 196 after the upper forming flange 150 has been passed through. The insulation cover 196 has an insulation passage 198 through which the punch of the upper forming unit 148 is passed.This provides a good mounting option for the high-temperature chamber 152 without causing significant losses in the upper region of the thermal insulation 156.

[0087] Figure 10 shows that a guide groove 200, in which the thermal insulation 156 is arranged, can be provided in the temperature control housing 103 of the temperature control chamber 102. The housing 154 is provided next to the guide groove 200. Upon thermal expansion of the thermal insulation 156, it is advantageously guided within the guide groove 200.

[0088] Figure 11 shows an exemplary method. In step 300, the glass blank 130 is tempered below a forming temperature within the tempering chamber 102. In step 302, the glass blank 130 is moved vertically from the tempering chamber 102 into the high-temperature chamber 152. In step 304, a local temperature gradient is established along a vertical axis within the high-temperature chamber 152 so that the glass blank 130 is advantageously tempered. In step 306, the glass blank 130 is moved vertically from the high-temperature chamber 152 into the tempering chamber 102.

[0089] In step 308, the glass blank 130 is tempered to the forming temperature. Subsequently, in step 310, the formed glass blank 130 is moved vertically back from the high-temperature chamber 152 into the tempering chamber 102 and then moved horizontally into a cooling section 118.

[0090] The manufacturing system 100 described above and the corresponding method enable high-temperature forming of glass blanks 130, particularly quartz glass, on an industrial scale. A cycle time of just a few minutes enables the production of formed glass blanks 130 from high-temperature glass with a short cycle time. The concepts of the transfer machine and the batch furnace are cleverly combined to utilize the advantages and, in particular, eliminate the existing disadvantages.

[0091] REFERENCE SYMBOL

[0092] 100 manufacturing system

[0093] 102 Temperature chamber

[0094] 103 Temperature control housing

[0095] 104 Entrance

[0096] 106 Outlet

[0097] 108 Inlet lock

[0098] 110 Outlet lock

[0099] 112 Main movement

[0100] 114 Preheating section

[0101] 116 transfer section

[0102] 118 Cooling section

[0103] 120 heating station

[0104] 122 upper heating unit

[0105] 124 lower heating unit

[0106] 126 electric heating cartridge

[0107] 128 forming tool

[0108] 130 glass blanks

[0109] 132 Forming tool

[0110] 134 Forming tool

[0111] 136 Forming tool

[0112] 138 Forming tool

[0113] 140 Lock

[0114] 142 forming device 143 vertical movement

[0115] 144 lower forming unit

[0116] 146 lower forming flange

[0117] 148 upper forming unit

[0118] 150 upper forming flange

[0119] 152 High-temperature chamber

[0120] 153 Interior

[0121] 154 housings

[0122] 156 thermal insulation

[0123] 158 Transfer opening

[0124] 160 heating unit

[0125] 162 Heating element

[0126] 164 first temperature range

[0127] 166 second temperature range

[0128] 168 third temperature range

[0129] 170 fourth temperature range

[0130] 172 external insulation

[0131] 174 medium insulation

[0132] 176 internal insulation

[0133] 178 inner opening diameter

[0134] 180 average opening diameter

[0135] 182 outer opening diameter

[0136] 184 Heating element

[0137] 186 Heating element 188 Heating element

[0138] 190 cooling channel

[0139] 192 Seal

[0140] 194 Insulation opening 196 Insulation cover

[0141] 198 Insulation penetration

[0142] 200 guide groove

Claims

CLAIMS 1. A manufacturing system (100) for the high-temperature forming of glass blanks (130), preferably glass blanks (130) made of quartz glass, in particular for the production of optical lenses, comprising a tempering chamber (102) for tempering the glass blank (130) below a forming temperature, through which the glass blanks (130) can be moved in a horizontal feed direction (112), a high-temperature chamber (152) with a heating unit (160) for tempering the glass blank (130) to a forming temperature, which is preferably greater than 1,400°C, - wherein the tempering chamber (102) and the high-temperature chamber (152) are connected to one another in a fluid-tight manner and have a transfer opening (158) through which the glass blanks (130) can be moved, a forming device (142) which is arranged and designed to move the glass blank (130) from the tempering chamber (102) through the transfer opening (158) into the high-temperature chamber (152) with a vertical movement (143) and to form the glass blank (130) in the high-temperature chamber (152).

2. Manufacturing system (100) according to claim 1, wherein the glass blank (130) is movable with a main movement from an inlet (104) to an outlet (106) through the tempering chamber (102), the tempering chamber (102) has a preheating section (114) adjacent to the inlet (104), a cooling section (118) adjacent to the outlet (106) and a transfer section (116) provided between the preheating section (114) and the cooling section (118), and the forming device (142) is arranged and designed to move the glass blank (130) from the transfer section (116) into the high-temperature chamber (152).

3. Manufacturing system (100) according to one of the preceding claims, wherein the transfer section (116) is thermally decoupled from the preheating section (114) and / or the cooling section (118) such that heat transfer from the high-temperature chamber (152) and / or the transfer section (116) to the preheating section (114) and / or the cooling section (118) is reduced.

4. Manufacturing system (100) according to one of the preceding claims, wherein the high-temperature chamber (152) is arranged vertically above the tempering chamber (102) and preferably vertically above the transfer section (116), and the tempering chamber (102) and the high-temperature chamber (152) are mounted to one another in a floating manner, in particular in a horizontal direction.

5. Manufacturing system (100) according to one of the preceding claims, wherein the forming device (142) is arranged and designed to partially close the transfer opening (158) during the vertical movement (143) so that a gap is formed between the chambers (102, 152) in order to compensate for thermal expansion.

6. Manufacturing system (100) according to one of the preceding claims, wherein the high-temperature chamber (152) is surrounded by a thermal insulation (156) arranged and configured to High-temperature chamber (152) to be thermally insulated from an environment, and the thermal insulation (156) is surrounded by a fluid-tight housing (154) which is arranged and designed to reduce fluid exchange between the high-temperature chamber (152) and the environment.

7. Manufacturing system (100) according to one of the preceding claims, wherein the forming device (142) has a lower forming unit (144) and an upper forming unit (148), the lower forming unit (144) is arranged and designed to carry out the vertical movement (143), in particular to move the glass blank (130) from the transfer section (116) into the high-temperature chamber (152), and - preferably the upper forming unit (148) is arranged and designed to carry out a second vertical movement which is oriented opposite to the vertical movement (143).

8. Manufacturing system (100) according to one of the preceding claims, wherein the high-temperature chamber (152) and the heating unit (160) are arranged and designed to maintain a constant temperature within the high-temperature chamber (152) during normal operation.

9. Manufacturing system (100) according to one of the preceding claims, wherein the heating unit (160) is arranged and designed to form a temperature profile in the high-temperature chamber (152) such that the glass blank (130) can be tempered depending on a position in the high-temperature chamber (152) in order to set a predetermined temperature profile in the glass blank (130) by means of a retraction speed of the forming device (142).

10. Manufacturing system (100) according to one of the preceding claims, wherein the heating unit (160) forms two or more heating zones within the high-temperature chamber (152), the heating zones being formed by means of separate heating elements (184, 186, 188), - preferably the two or more heating zones are formed vertically adjacent to each other, and - preferably the heating elements (184, 186, 188) are arranged offset from one another in the horizontal direction.

11. Manufacturing system (100) according to one of the preceding claims, comprising a control unit arranged and designed to control the movement and / or speed of the forming device (142), - wherein preferably the vertical movement (143) is controlled such that based on the speed of the glass blank (130) is tempered with a predefined temperature curve.

12. Manufacturing system (100) according to one of the preceding claims, wherein the control unit is designed to adjust a vertical position of the glass blank (130) during the forming according to a predefined movement pattern by controlling the forming device (142), preferably the upper and lower forming unit.

13. Manufacturing system (100) according to one of the preceding claims, wherein the control unit is designed to control the heating unit (160) such that the temperature within the high-temperature chamber (152) is constant.

14. A method for high-temperature forming of glass blanks (130), preferably glass blanks (130) made of quartz glass, in particular for producing optical lenses, preferably with a production system according to one of the preceding claims 1-13, comprising the steps: - tempering the glass blank below a forming temperature within a tempering chamber (102) through which the glass blank (130) is moved in a horizontal feed direction, - Vertically moving the glass blank from the tempering chamber (102) into a high-temperature chamber (152) fluid-tightly connected to the tempering chamber (102), and - Tempering the glass blank to a forming temperature and forming the glass blank within the high-temperature chamber (152).

15. Method according to the preceding claim 14, comprising the step or steps: - Vertically moving the formed glass from the high-temperature chamber (152) into the tempering chamber (102), and - preferably horizontal movement of the formed glass into a cooling section.

16. A method according to any one of the preceding claims 14-15, comprising the step or steps: Setting a constant temperature within the high-temperature chamber (152), and / or Setting local temperature gradients, in particular along a vertical axis, within the high-temperature chamber (152).

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