Preform rod bending detection device and correction system

Abstract

The utility model relates to a preform rod bending detection device and correction system, the device comprises: a first detection assembly comprising a first laser emitter and a first laser receiver, the first laser emitter emits a first light beam along a first linear direction, the first laser receiver is used for receiving the first light beam, and the first laser receiver is used for receiving the first light beam; the first laser transmitter and the first laser receiver are arranged on the two sides of the reference axis in the radial direction, and the reference axis is perpendicular to the first linear direction and the second linear direction and located in a light path of the first light beam; the second detection assembly comprises a second laser emitter and a second laser receiver, the second laser emitter is used for emitting a second light beam in the second linear direction, the second laser receiver is used for receiving the second light beam, and the second laser emitter and the second laser receiver are arranged on the two sides of the reference axis in the radial direction; the reference axis is located in a light path of the second light beam. According to the invention, accurate detection of the bending direction and the bending degree of the handle bar to be detected can be realized.

Description

Technical Field

[0001] The utility model relates to the field of optical fiber preform processing technology, and particularly relates to a preform handle bending detection device and a correction system. Background Technique

[0002] In the manufacturing process of an optical fiber preform, after undergoing the OVD sintering process for dehydration and high-temperature sintering into a transparent optical fiber preform, operations need to be carried out in the tip processing process, heating and softening the lower part of the preform into a cone shape to facilitate the customer's optical fiber drawing operation.

[0003] In the sintering process, during the shrinkage and transparency process of the preform, the lower handle will bend relative to the preform body. After the preform reaches the tip processing process, when the lower chuck of the tip processing equipment clamps the lower handle with excessive bending, it is easy to cause the lower handle to break.

[0004] Therefore, it is necessary to detect the bending degree of the handle before the lower chuck of the tip processing equipment clamps the handle, so as to carry out correction processing. Content of the Utility Model

[0005] Based on the above description, the utility model provides a preform handle bending detection device and a correction system to detect the bending degree of the handle before the lower chuck of the tip processing equipment clamps the handle, and correct the bent handle.

[0006] The technical solution for the utility model to solve the above technical problems is as follows:

[0007] In the first aspect, the present application provides a preform handle bending detection device, and the technical solution adopted is as follows:

[0008] A preform handle bending detection device includes:

[0009] A first detection component, which includes a first laser emitter and a first laser receiver. The first laser emitter is used to emit a first light beam along a first straight line direction, and the first light beam has a set width in a second straight line direction perpendicular to the first straight line direction. The first laser receiver is used to receive the first light beam. The first laser emitter and the first laser receiver are arranged on both sides of the reference axis in the radial direction. The reference axis is perpendicular to both the first straight line direction and the second straight line direction and is located in the optical path of the first light beam;

[0010] The second detection component, which includes a second laser emitter and a second laser receiver. The second laser emitter is used to emit a second light beam along a second straight line direction, and the second light beam has a set width in a first straight line direction. The second laser receiver is used to receive the second light beam. The second laser emitter and the second laser receiver are arranged on two sides in the radial direction of the reference axis, and the reference axis is located in the optical path of the second light beam;

[0011] Wherein, a standard bar with an axis coinciding with the axis of the preform is located in the optical paths of the first light beam and the second light beam. When the axis of the standard bar coincides with the reference axis, the first light beam and the second light beam are partially blocked by the standard bar. It is suitable to place the bar to be measured in the optical paths of the first light beam and the second light beam, and make the axis of the preform connected to the bar to be measured coincide with the reference axis. According to the comparison result between the width data of the first light beam blocked by the bar to be measured received by the first laser receiver and the corresponding reference parameter, it is judged whether the bar to be measured is bent relative to the preform in the second straight line direction, and according to the comparison result between the width data of the second light beam blocked by the bar to be measured received by the second laser receiver and the corresponding reference parameter, it is judged whether the bar to be measured is bent relative to the preform in the first straight line direction.

[0012] Preferably, the width of the first light beam in the second straight line direction and the width of the second light beam in the first straight line direction are both not less than the diameter of the bar.

[0013] Preferably, the reference axis is equidistant from the two side boundaries of the first light beam in the second straight line direction and is equidistant from the two side boundaries of the second light beam in the first straight line direction.

[0014] In a second aspect, the present application provides a preform bar bending correction system, including:

[0015] The preform bar bending detection device as described in the first aspect above, wherein both the first straight line direction and the second straight line direction are horizontal, and the reference axis is vertical;

[0016] A heating device, which is used to heat the bar to soften the bar, and is suitable to make the softened bar return to a vertical axis state through the action of gravity;

[0017] A controller, the first laser receiver, the second laser receiver and the heating device are all connected to the controller. The controller judges whether the bar to be measured is bent relative to the preform in the second straight line direction according to the width data of the first light beam received by the first laser receiver, and judges whether the bar to be measured is bent relative to the preform in the first straight line direction according to the width data of the second light beam received by the second laser receiver. The controller is also used to control the heating device to start or stop.

[0018] Preferably, the controller calculates the angle formed by the axis of the handle rod and the axis of the preform rod according to the width of the first light beam received by the first laser receiver and the corresponding reference parameter, and the width of the second light beam received by the second laser receiver and the corresponding reference parameter, and controls the heating device to start when the angle exceeds a set value.

[0019] Preferably, the heating device heats one end of the handle rod close to the preform rod.

[0020] Preferably, the heating device includes a hydrogen-oxygen flame heating device.

[0021] In a third aspect, the present application provides a method for correcting the bending of a handle rod of a preform, which is corrected by using the preform handle rod bending correction system described in the second aspect above.

[0022] Compared with the prior art, the technical solution of the present application has at least the following beneficial technical effects:

[0023] 1. By setting the first detection component and the second detection component in the detection device of the present application, in the first detection component, the first laser emitter emits a first light beam with a set width. For a standard handle rod, its axis is coaxial with the axis of the preform rod. When the standard handle rod is placed in the optical path of the first light beam and its axis coincides with the reference axis, the first light beam is partially blocked by the standard handle rod. At this time, the first laser receiver receives a part of the first light beam, and uses the width of this part of the first light beam as the reference parameter; when detecting the handle rod to be measured, if the width of the part of the first light beam received by the first laser receiver changes, it indicates that the handle rod to be measured is offset in the second straight line direction compared with the standard handle rod, that is, the handle rod to be measured is bent relative to the preform rod in the second straight line direction. Thus, it can be judged whether the handle rod to be measured is bent in the second straight line direction, and according to whether the width of the first light beam received by the first laser receiver increases or decreases, the specific bending direction of the handle rod to be measured in the second straight line direction can be judged. Similarly, through the second detection component, it can be judged whether the handle rod to be measured is bent in the first straight line direction, and the specific bending direction of the handle rod to be measured in the first straight line direction can be judged, so as to realize the judgment of whether the handle rod of the preform is bent. At the same time, according to the width of the first light beam received by the first laser receiver and the corresponding reference parameter, the width of the second light beam received by the second laser receiver and the corresponding reference parameter, and the distances between the first light beam and the second light beam and the preform rod in the axial direction of the reference axis, the angle formed by the axis of the handle rod and the axis of the preform rod can be calculated, as well as the specific bending direction, so as to realize the accurate detection of the bending direction and bending degree of the handle rod to be measured.

[0024] 2. The detection device of the present application ensures that the width of the first light beam in the second linear direction and the width of the second light beam in the first linear direction are both not less than the diameter of the rod blank. The reference axis is equidistant from the two side boundaries of the first light beam in the second linear direction and equidistant from the two side boundaries of the second light beam in the first linear direction. When the first light beam is blocked by the rod blank to be measured, two discontinuous first light beams in the second linear direction are received by the first laser receiver. By comparing the widths of the two first light beams with the corresponding width reference values, the bending degree and bending direction of the rod blank to be measured in the second linear direction can be judged more precisely. Similarly, by comparing the widths of the two second light beams received by the second laser receiver with the corresponding width reference values, the bending degree and bending direction of the rod blank to be measured in the first linear direction can be judged more precisely.

[0025] 3. The preform rod blank bending correction system of the present application detects whether the rod blank to be measured is bent through the detection device and the controller, and controls the heating device to start or operate through the controller. When the heating device starts, the rod blank is heated to make it soft. Since the axis of the preform is vertical, the rod blank will return to the vertical axis state under the action of gravity after being heated and softened, thereby realizing the correction of the bent rod blank. The operator can control whether to start heating through the controller according to the detection result of the rod blank bending by the cooperation of the controller and the detection device, so as to start the heating device to correct the rod blank when the rod blank is bent, so that it can be clamped by the lower chuck of the tip processing equipment and avoid breaking the rod blank. Description of the Drawings

[0026] Figure 1 is a schematic structural diagram of the preform rod blank bending detection device provided by an embodiment of the present invention;

[0027] Figure 2 is a schematic diagram when the preform rod blank bending detection device provided by an embodiment of the present invention detects the rod blank to be measured;

[0028] Figure 3 is a schematic structural diagram of the preform rod blank bending correction system provided by an embodiment of the present invention.

[0029] Description of the Reference Numerals:

[0030] 1. First laser emitter; 2. First laser receiver; 3. Second laser emitter; 4. Second laser receiver; 5. Heating device; 6. Controller; 7. Preform; 8. Tip processing furnace; 9. Chuck. Detailed Embodiments

[0031] To facilitate the understanding of the present application, the present application will be described more comprehensively hereinafter with reference to the relevant drawings. Embodiments of the present application are shown in the drawings. However, the present application may be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided so that the disclosure of the present application is thorough and comprehensive.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application.

[0033] It can be understood that spatial relationship terms such as "under", "below", "beneath", "underneath", "above", "over" etc. can be used herein to describe the relationship of one element or feature shown in the figure with other elements or features. It should be understood that in addition to the orientation shown in the figure, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, an element or feature described as "under other elements" or "beneath it" or "under it" will be oriented "above" other elements or features. Therefore, the exemplary terms "under" and "below" can include both the upper and lower orientations. In addition, the device can also include other orientations (such as rotating 90 degrees or other orientations), and the spatial descriptions used herein are accordingly interpreted.

[0034] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element or connected to the other element through an intermediate element. In the following embodiments, "connection", if there is an electrical signal or data transmission between the connected circuits, modules, units, etc., should be understood as "electrical connection", "communication connection", etc.

[0035] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprise / include" or "have" etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof.

[0036] Refer to Figure 1-2 As shown, an optical fiber preform bar bending detection device is provided in an embodiment of the present application, which includes a first detection component and a second detection component.

[0037] Refer to Figure 1-2As shown in the figure, the first detection component includes a first laser emitter 1 and a first laser receiver 2. The first laser emitter 1 is used to emit a first light beam along a first straight line direction, and the first light beam has a set width in a second straight line direction perpendicular to the first straight line direction. The first laser receiver 2 is used to receive the first light beam. The first laser emitter 1 and the first laser receiver 2 are arranged on both sides of the reference axis in the radial direction. The reference axis is perpendicular to both the first straight line direction and the second straight line direction and is located in the optical path of the first light beam.

[0038] Referring to Figure 1-2 As shown in the figure, the second detection component includes a second laser emitter 3 and a second laser receiver 4. The second laser emitter 3 is used to emit a second light beam along the second straight line direction, and the second light beam has a set width in the first straight line direction. The second laser receiver 4 is used to receive the second light beam. The second laser emitter 3 and the second laser receiver 4 are arranged on both sides of the reference axis in the radial direction. The reference axis is located in the optical path of the second light beam.

[0039] Among them, when setting the position of the reference axis and the widths of the first light beam and the second light beam, a standard bar whose axis coincides with the axis of the preform 7 is located in the optical paths of the first light beam and the second light beam. When the axis of the standard bar coincides with the reference axis, the first light beam and the second light beam are partially blocked by the standard bar. During the detection, the bar to be measured is placed in the optical paths of the first light beam and the second light beam, and the axis of the preform 7 connected to the bar to be measured is made to coincide with the reference axis. According to the comparison result between the width data of the first light beam blocked by the bar to be measured received by the first laser receiver 2 and the corresponding reference parameter, it is judged whether the bar to be measured is bent relative to the preform 7 in the second straight line direction. According to the comparison result between the width data of the second light beam blocked by the bar to be measured received by the second laser receiver 4 and the corresponding reference parameter, it is judged whether the bar to be measured is bent relative to the preform 7 in the first straight line direction.

[0040] For a standard bar located in the optical paths of the first light beam and the second light beam, the first laser receiver 2 and the second laser receiver 4 respectively receive the first light beam and the second light beam blocked by the standard bar, and the widths of the light beams received by the first laser receiver 2 and the second laser receiver 4 are used as reference parameters. For the bar under test located in the optical paths of the first light beam and the second light beam, if it is bent relative to the preform 7, the axis of the bar under test will be offset relative to the axis of the standard bar. At this time, the width of the first light beam blocked by the bar under test received by the first laser receiver 2 changes relative to the reference parameter, and / or the width of the second light beam blocked by the bar under test received by the second laser receiver 4 changes relative to the reference parameter. Therefore, by comparing the width data of the first light beam blocked by the bar under test received by the first laser receiver 2 with the corresponding reference parameter, it can be determined whether the bar under test is bent relative to the preform 7 in the second linear direction. By comparing the width data of the second light beam blocked by the bar under test received by the second laser receiver 4 with the corresponding reference data, it can be determined whether the bar under test is bent relative to the preform 7 in the first linear direction.

[0041] Referring to Figure 1-2 As shown, to more accurately determine the bending direction and bending angle of the bar under test relative to the preform 7, the width of the first light beam in the second linear direction and the width of the second light beam in the first linear direction are both not less than the diameter of the bar. At the same time, the reference axis is equidistant from the two side boundaries of the first light beam in the second linear direction and equidistant from the two side boundaries of the second light beam in the first linear direction.

[0042] With this setting, for the standard bar located in the optical paths of the first beam and the second beam, after the first beam and the second beam are blocked by the standard bar, the first laser receiver 2 receives two discontinuous first beams in the second linear direction. The widths of the two first beams are the same and serve as reference parameters. The second laser receiver 4 receives two discontinuous second beams in the first linear direction. The widths of the two second beams are the same and serve as reference parameters. When detecting the bar to be measured, the bar to be measured is located in the optical paths of the first beam and the second beam. If it is bent relative to the preform 7, the axis of the bar to be measured will be offset relative to the axis of the standard bar. At this time, the widths of the two first beams blocked by the bar to be measured received by the first laser receiver 2 change relative to the reference parameters, and / or the widths of the two second beams blocked by the bar to be measured received by the second laser receiver 4 change relative to the reference parameters. According to the specific changes of the two first beams relative to the reference parameters, the specific bending direction and bending degree of the bar to be measured in the second linear direction can be judged. According to the specific changes of the two second beams relative to the reference parameters, the specific bending direction and bending degree of the bar to be measured in the first linear direction can be judged. Thus, the bending degree and bending direction of the bar to be measured in the first linear direction and the second linear direction can be judged more accurately.

[0043] In this embodiment, the first beam and the second beam are located in a plane perpendicular to the reference axis. During actual detection, the distances between the first beam and the second beam in the axial direction of the reference axis and the preform 7 connected to the bar to be measured are known parameters. By establishing a spatial coordinate system with the first linear direction and the second linear direction as the X-axis and the Y-axis respectively, and the reference axis as the Z-axis, the bending direction of the axis of the bar to be measured relative to the axis of the preform 7, and the included angle formed by the axis of the bar to be measured and the axis of the preform 7 can be calculated according to the detection data, and then the specific bending degree of the bar to be measured can be calculated. The operator can judge whether correction is needed according to the specific bending degree of the bar to be measured.

[0044] Referring to Figure 1-3 As shown, the embodiment of the present application further provides a preform bar bending correction system, including the preform bar bending detection device, the heating device 5 and the controller 6 as described above.

[0045] Referring to Figure 1-3 As shown, wherein, both the first linear direction and the second linear direction are horizontal, and the reference axis is vertical. At this time, when the axis of the preform 7 connected to the bar to be measured coincides with the reference axis, it is in the axis vertical state, and when the bar to be measured is bent, it is relative to the vertical axis. The heating device 5 is provided to heat the bar to soften the bar, and through the action of gravity, the softened bar is restored to the axis vertical state.

[0046] During tip processing, the preform 7 is usually clamped and moved by the spindle moving unit, and the preform 7 is kept in a state where its axis is vertical. The lower part of the rod passes through the tip processing furnace 8 from top to bottom and is clamped and fixed by the chuck 9. Therefore, in this application, the preform rod bending detection device and the heating device 5 are set according to the state of the preform 7 when it enters the tip processing equipment. When the preform 7 enters the tip processing equipment and the lower rod has not been clamped by the chuck 9 of the tip processing equipment, the preform rod bending detection device is used to detect whether the rod is bent, and when it is bent, the heating device 5 is started to correct the rod to ensure that the chuck 9 can safely clamp the lower rod.

[0047] Referring to Figure 1-3 As shown, the first laser receiver 2, the second laser receiver 4, and the heating device 5 are all connected to the controller 6. The controller 6 judges whether the measured rod is bent relative to the preform 7 in the second straight line direction according to the width data of the first light beam received by the first laser receiver 2, and judges whether the measured rod is bent relative to the preform 7 in the first straight line direction according to the width data of the second light beam received by the second laser receiver 4. The controller 6 is also used to control the heating device 5 to start or stop.

[0048] Referring to Figure 1-3 As shown, specifically, when the measured rod reaches the set position of the tip processing equipment and has not been clamped by the chuck 9, the first laser receiver 2 and the second laser receiver 4 respectively receive the first light beam and the second light beam blocked by the measured rod, and obtain the width data of the received first light beam and the second light beam. The data is transmitted to the controller 6. The controller 6 has a built-in program algorithm and database, compares the width data of the first light beam received by the first laser receiver 2 with the reference data, and compares the width data of the second light beam received by the second laser receiver 4 with the reference data, so as to judge whether the measured rod is bent relative to the preform 7 in the first straight line direction and the second straight line direction. The controller 6 decides whether to start the heating device 5 according to the comparison result. When the measured rod is bent relative to the preform 7, the controller 6 controls the heating device 5 to start to heat the measured rod to make it soften, so that the measured rod returns to the state where its axis is vertical under the action of gravity. The bending detection and correction of the measured rod can be automatically completed while performing the normal processing procedure of the preform 7 entering the tip processing equipment, without separately performing the bending detection and correction of the measured rod, thereby improving the production efficiency.

[0049] Further, for the case where the bending degree of the to-be-tested handle rod is small, the chuck 9 is not likely to cause breakage when clamping the to-be-tested handle rod. In this case, the to-be-tested handle rod does not need to be corrected. Therefore, the controller 6 is set to calculate the angle formed by the axis of the handle rod and the axis of the preform rod 7 according to the width of the first light beam received by the first laser receiver 2 and the corresponding reference parameters, and the width of the second light beam received by the second laser receiver 4 and the corresponding reference parameters, and control the heating device 5 to start when the angle exceeds the set value. Specifically, the distances between the first light beam and the second light beam in the axial direction of the reference axis and the preform rod 7 connected to the to-be-tested handle rod are known parameters. The controller 6 calculates the angle formed by the axis of the to-be-tested handle rod and the axis of the preform rod 7 according to the width of the first light beam received by the first laser receiver 2 and the corresponding reference parameters, and the width of the second light beam received by the second laser receiver 4 and the corresponding reference parameters through the built-in software algorithm, so as to judge the bending degree of the to-be-tested handle rod. When the angle formed by the axis of the to-be-tested handle rod and the axis of the preform rod 7 exceeds the set value, the controller 6 controls the heating device 5 to start to heat and correct the to-be-tested handle rod. It is possible not to correct the to-be-tested handle rod when its bending degree is small, reducing the process and improving the production efficiency.

[0050] Referring to Figure 3 As shown, further, the heating device 5 adopts a hydrogen-oxygen flame heating device 5. When setting the heating device 5, since the handle rod bends relative to the preform rod 7 at the end close to the preform rod 7 when bending, the heating device 5 is set at the end of the handle rod close to the preform rod 7. By heating the end of the handle rod close to the preform rod 7 with the heating device 5 to soften it, the handle rod can be restored to the vertical axis state under the action of gravity.

[0051] This embodiment also provides a method for correcting the bending of the preform handle rod, which is corrected by using the preform handle rod bending correction system as described above.

[0052] The method for correcting the bending of the preform handle rod described here is as described in the above embodiment. For the sake of brevity, it will not be repeated here.

[0053] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preform bar bending detection device, characterized in that, Comprising: A first detection component, which includes a first laser emitter (1) and a first laser receiver (2). The first laser emitter (1) is used to emit a first light beam along a first straight line direction, and the first light beam has a set width in a second straight line direction perpendicular to the first straight line direction. The first laser receiver (2) is used to receive the first light beam. The first laser emitter (1) and the first laser receiver (2) are arranged on both sides in the radial direction of a reference axis. The reference axis is perpendicular to both the first straight line direction and the second straight line direction and is located in the optical path of the first light beam; A second detection component, which includes a second laser emitter (3) and a second laser receiver (4). The second laser emitter (3) is used to emit a second light beam along the second straight line direction, and the second light beam has a set width in the first straight line direction. The second laser receiver (4) is used to receive the second light beam. The second laser emitter (3) and the second laser receiver (4) are arranged on both sides in the radial direction of the reference axis. The reference axis is located in the optical path of the second light beam; Wherein, a standard bar with an axis coinciding with the axis of the preform (7) is located in the optical paths of the first light beam and the second light beam. When the axis of the standard bar coincides with the reference axis, the first light beam and the second light beam are partially blocked by the standard bar. It is suitable to place the bar to be measured in the optical paths of the first light beam and the second light beam, and make the axis of the preform (7) connected to the bar to be measured coincide with the reference axis. According to the comparison result between the width data of the first light beam blocked by the bar to be measured received by the first laser receiver (2) and the corresponding reference parameter, it is judged whether the bar to be measured is bent relative to the preform (7) in the second straight line direction. And according to the comparison result between the width data of the second light beam blocked by the bar to be measured received by the second laser receiver (4) and the corresponding reference parameter, it is judged whether the bar to be measured is bent relative to the preform (7) in the first straight line direction.

2. The preform bar bending detection device according to claim 1, characterized in that: The width of the first light beam in the second straight line direction and the width of the second light beam in the first straight line direction are both not less than the diameter of the bar.

3. The preform bar bending detection device according to claim 2, wherein: The reference axis is equidistant from the two side boundaries of the first light beam in the second straight line direction, and is equidistant from the two side boundaries of the second light beam in the first straight line direction.

4. A preform rod bending and correcting system, characterized in that Comprising: The preform bar bending detection device according to any one of claims 1-3, wherein both the first straight line direction and the second straight line direction are horizontal, and the reference axis is vertical; A heating device (5), which is used to heat the bar to soften the bar, so as to make the softened bar return to a vertical axis state under the action of gravity; A controller (6), wherein the first laser receiver (2), the second laser receiver (4) and the heating device (5) are all connected to the controller (6). The controller (6) determines whether the measured rod is bent relative to the preform (7) in the second linear direction according to the width data of the first light beam received by the first laser receiver (2), and determines whether the measured rod is bent relative to the preform (7) in the first linear direction according to the width data of the second light beam received by the second laser receiver (4). The controller (6) is further configured to control the heating device (5) to start or stop.

5. The preform rod bending and straightening system according to claim 4, characterized in that: The controller (6) calculates the angle formed by the axis of the rod and the axis of the preform (7) according to the width of the first light beam received by the first laser receiver (2) and the corresponding reference parameter, and the width of the second light beam received by the second laser receiver (4) and the corresponding reference parameter, and controls the heating device (5) to start when the angle exceeds a set value.

6. The preform rod bending and straightening correction system according to claim 4, characterized in that: The heating device (5) heats one end of the rod close to the preform (7).

7. The preform rod bending and straightening system according to claim 4, wherein: The heating device (5) includes a hydrogen-oxygen flame heating device (5).

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