JP2019007521A - Heat insulation lid structure - Google Patents

Abstract

To provide a heat insulation lid structure which can exhibit sufficient heat insulation performance, and can be easily manufactured.SOLUTION: A heat insulation lid structure 1 according to the invention includes an inner end plate 2, an outer end plate 3 positioned at an outer side of the inner end plate 2, and a tubular member 8 welded to the inner end plate 2 and the outer end plate 3 and forming a sealed space 5 in a pressure-reduced state together with the inner end plate 2 and the outer end plate 3. The tubular member 8 includes a tubular member 6 welded to an end of the inner end plate 2, a tubular member 7 welded to an end of the outer end plate 3, and a tubular member 4 welded to the tubular member 6 and the tubular member 7. A thickness of the tubular member 4 is thinner than thicknesses of the inner end plate 2, the tubular member 6, the outer end plate 3, and the tubular member 7. The tubular member 6 has a shape having an outside diameter of the tubular member 6 which decreases from a welded position of the tubular member 6 and the tubular member 4 toward a welded position of the tubular member 6 and the inner end plate 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a heat insulating lid structure.

  There is known a heat insulating lid structure in which an end portion of an inner end plate and an end portion of an outer end plate are welded to form a decompressed space in a gap between the inner end plate and the outer end plate. Such a heat insulating lid structure can be used as a lid of a heating furnace, for example.

  Patent Document 1 includes a metal bottomed and cylindrical inner member and a metal bottomed and cylindrical outer member. The inner member and the outer member are joined on the opening side, and the inner member is A double insulated container having a thin wall portion with a thin plate thickness in the vicinity of the joint portion is disclosed.

Japanese Unexamined Patent Publication No. 2017-006598

  FIG. 7 is a cross-sectional view illustrating the configuration of a conventional heat insulating lid structure 100. As shown in FIG. 7, the heat insulating lid structure 100 includes an inner end plate 102, an outer end plate 103, and a tube member 104 (sealing member).

  The inner end plate 102 and the outer end plate 103 are circular curved plates. The inner end plate 102 is disposed on the positive side in the x-axis direction with respect to the outer end plate 103. Further, the inner end plate 102 and the outer end plate 103 have convex surfaces on the minus side in the x-axis direction. The tube member 104 seals a space 105 between the inner end plate 102 and the outer end plate 103. The end of the inner end plate 102 and the pipe member 104 are joined by welding at the welding position 106b. The end of the outer end plate 103 and the pipe member 104 are joined by welding at the welding position 107b.

  Here, when the heat insulating lid structure 100 is used as a lid for a heating furnace, the inner end plate 102 is heated to a high temperature, and heat is transferred from the inner end plate 102 to the outer end plate 103 via the tube member 104. In consideration of this point, in the heat insulating lid structure 100 shown in FIG. 7, the thickness of the tube member 104 is reduced to reduce the heat transmitted from the inner end plate 102 to the outer end plate 103.

  However, when the plate thickness of the tube member 104 is made thinner than the plate thickness of the inner end plate 102 and the outer end plate 103, it is difficult to accurately weld the inner end plate 102 and the tube member 104, and the outer end plate 103 and the tube member 104. There is a problem that. That is, the inner end plate 102 and the outer end plate 103 are heavy because they have a large diameter and a large plate thickness. Therefore, handling is difficult and it is difficult to perform precise welding work.

  This invention is made | formed in view of the above subject, and it aims at providing the heat insulation lid | cover structure which has high heat insulation performance and is easy to produce.

  The heat insulating lid structure according to the present invention is welded to the inner end plate, the outer end plate located outside the inner end plate, the inner end plate and the outer end plate, and the sealed space in a decompressed state together with the inner end plate and the outer end plate. A tubular member. The tubular member includes a first tube member welded to an end portion of the inner end plate, a second tube member welded to an end portion of the outer end plate, the first tube member, and the second tube member. And a third pipe member welded to each other. The thickness of the third tube member is thinner than the thickness of the inner end plate, the first tube member, the outer end plate, and the second tube member. Further, the first pipe member has an outer diameter of the first pipe member from a welding position between the first pipe member and the third pipe member toward a welding position between the first pipe member and the inner end plate. Has a smaller shape.

  In the heat insulating lid structure according to the present invention, the first tube member welded to the end portion of the inner end plate, the second tube member welded to the end portion of the outer end plate, the first tube member and the second tube member, And a third pipe member welded to each other to form a tubular member. The thickness of the third tube member is made thinner than the thickness of the inner end plate, the first tube member, the outer end plate, and the second tube member. Therefore, the heat insulation performance of the heat insulation lid structure can be improved. In addition, since the thick first tube member and the inner end plate are welded and the thick second tube member and the outer end plate are welded, the inner end plate, the outer end plate, and the tubular member are welded with high accuracy. Can do. Therefore, it is possible to provide a heat insulating lid structure having high heat insulating performance and easy to manufacture.

  Further, in the heat insulating lid structure according to the present invention, the outer diameter of the first pipe member decreases from the welding position of the first pipe member and the third pipe member toward the welding position of the first pipe member and the inner end plate. In addition, the first pipe member is configured. When the inner end plate and the first tube member are expanded radially outward, the third tube member is stressed by the first tube member because the third tube member is joined to the first tube member. At this time, since the third pipe member and the first pipe member do not have corners at the portions where they are in contact with each other, the stress is unlikely to concentrate at one place. Therefore, damage to the third pipe member due to stress can be suppressed. Therefore, it is possible to provide a heat insulating lid structure in which the third tube member is not easily damaged during thermal expansion of the inner end plate.

  ADVANTAGE OF THE INVENTION According to this invention, it can provide the heat insulation lid | cover structure which has high heat insulation performance and is easy to produce.

It is sectional drawing which shows the heat insulation lid | cover structure concerning embodiment. It is sectional drawing which follows the II-II line | wire of FIG. It is sectional drawing which follows the III-III line of FIG. It is sectional drawing which shows the state which the inner side end plate is thermally expanding in the heat insulation lid structure concerning embodiment. It is sectional drawing which shows the heat insulation lid | cover structure of a structure where a pipe member is not provided with a curved surface part. FIG. 6 is a cross-sectional view showing a state in which the inner end plate is thermally expanded in the heat insulating lid structure shown in FIG. 5. It is a schematic diagram which shows the conventional heat insulation lid | cover structure.

Embodiments of the present invention will be described below with reference to the drawings.
Drawing 1 is a sectional view explaining the composition of heat insulation lid structure 1 concerning an embodiment. FIG. 2 is a cross-sectional view of the heat insulating lid structure 1 taken along line II-II in FIG. FIG. 3 is a cross-sectional view of the heat insulating lid structure 1 taken along the line III-III in FIG. As shown in FIG. 1, the heat insulating lid structure 1 includes an inner end plate 2, an outer end plate 3, and a tubular member 8.

  The inner end plate 2 and the outer end plate 3 are end plates that are circular and have a convex surface. More specifically, the inner end plate 2 is a disk-like structure that is convex in the x-axis minus direction.

  The outer end plate 3 is disposed on the outer side (x-axis minus direction) than the inner end plate 2. The outer end plate 3 is a disk-like structure that is convex in the negative direction of the x-axis, like the inner end plate 2.

  The inner end plate 2 and the outer end plate 3 can be formed using, for example, stainless steel or steel. The materials constituting the inner end plate 2 and the outer end plate 3 may be the same or different.

  The tubular member 8 seals the space 5 formed by the inner end plate 2 and the outer end plate 3 from the outside air. The tubular member 8 is joined to the inner end plate 2 at the welding position 6c. Further, the outer end plate 3 is joined at the welding position 7c. A space 5 formed by the inner end plate 2, the outer end plate 3, and the tubular member 8 is a sealed space in a reduced pressure state. For example, the space 5 is made a reduced pressure space by welding the tubular member 8 to the inner end plate 2 and the outer end plate 3 under reduced pressure conditions. Alternatively, a vacuum port (not shown) may be provided in advance on the outer end plate 3 or the like, and after the inner end plate 2 and the outer end plate 3 are welded to the tubular member 8, the pressure may be reduced by a vacuum pump via the vacuum port.

  As shown in FIG. 1, the tubular member 8 includes a tube member 6 (first tube member), a tube member 7 (second tube member), and a tube member 4 (third tube member). The pipe member 6, the pipe member 7, and the pipe member 4 are annular (see FIGS. 2 and 3). The plate thickness of the tube member 4 is thinner than the plate thickness of the tube member 6, the tube member 7, the inner end plate 2, and the outer end plate 3.

  The pipe member 4 is joined to the pipe member 6 at the end (welding position 6b) on the plus side in the x-axis direction of the pipe member 4. The tube member 4 is joined to the tube member 7 at the end (weld position 7b) on the minus side in the x-axis direction of the tube member 4. The tube member 6 and the tube member 7 are lighter in weight than the inner end plate 2 and the outer end plate 3. For example, the weight of a stainless steel end plate having a diameter of 2 m and a plate thickness of 4 mm is about 100 kg, whereas the weight of a stainless steel tube member having a diameter of 2 m, a plate thickness of 10 mm and a length of 20 mm is about 10 kg. Therefore, since handling at the time of welding becomes easy, the pipe member 4 can be welded to the pipe member 6 and the pipe member 7 with high accuracy.

  Moreover, when manufacturing the heat insulation lid structure 1 concerning this Embodiment, the pipe member 4 is joined to the pipe member 6 and the pipe member 7, and the tubular member 8 is formed previously. Thereafter, the inner end plate 2 and the tube member 6 are joined at the welding position 6c, and the outer end plate 3 and the tube member 7 are joined at the welding position 7c.

  When the tubular member 8 (tube member 6) and the inner end plate 2 are joined at the welding position 6c, since the inner end plate 2 and the tube member 6 are both thick, welding is facilitated. Therefore, the inner end plate 2 can be easily joined to the tubular member 8. Further, when the tubular member 8 (tube member 7) and the outer end plate 3 are joined at the welding position 7c, the outer end plate 3 and the tube member 7 are both thick, so that welding is facilitated. Therefore, the outer end plate 3 can be easily joined to the tubular member 8.

  The pipe member 6, the pipe member 7, and the pipe member 4 can be configured using, for example, stainless steel or steel. The material which comprises the pipe member 6, the pipe member 7, and the pipe member 4 may be the same, and may differ.

  The heat insulating lid structure 1 according to the present embodiment is used as a lid of a heating furnace by providing a heating furnace on the positive side in the x-axis direction, for example. For this reason, the inner side end plate 2 and the pipe member 6 become high temperature. Here, in the heat insulating lid structure 1 according to the present embodiment, as shown in FIG. 1, since the plate member 4 is thin, the amount of heat transferred from the tube member 6 to the tube member 7 via the tube member 4 is reduced. Few. That is, heat insulation between the inner end plate 2 and the outer end plate 3 can be ensured.

  Next, the behavior of the heat insulating lid structure 1 according to the present embodiment during heating expansion will be described with reference to FIG. FIG. 4 is a cross-sectional view illustrating a state of the heat insulating lid structure 1 according to the present embodiment when heated and expanded.

  As shown in FIG. 4, for example, when a heating furnace provided on the x-axis plus side with respect to the tube member 6 is heated, the heat of the heating furnace is transmitted to the inner end plate 2 and the tube member 6, and the inner end plate 2 and the tube member 6 thermally expands radially outward. In FIG. 4, the states of the inner end plate 2 and the tube member 6 before heating are indicated by broken lines. On the other hand, since the tube member 7 is in contact with the tube member 6 via the tube member 4 having a thin plate thickness, almost no heat is transmitted to the outer end plate 3 and the tube member 7. Therefore, even if the inner end plate 2 and the tube member 6 are thermally expanded, the outer end plate 3 and the tube member 7 hardly thermally expand. At this time, since the tube member 4 is joined to the tube member 6 and the tube member 7, the end on the x-axis plus side of the tube member 4 expands radially outward with the thermal expansion of the tube member 6.

  Here, the pipe member 6 has a curved surface portion 6d in which the outer diameter of the pipe member 6 decreases from the welding position 6b toward the welding position 6c. In the heat insulating lid structure 1 according to the present embodiment, when the inner end plate 2 and the tube member 6 are thermally expanded and the inner end plate 2 and the tube member 6 expand radially outward as shown in FIG. Since the end on the x-axis plus side of 4 is in contact with the curved surface portion 6d of the tube member 6, it is possible to suppress the stress acting on the tube member 4 from the tube member 6 from being concentrated on one point. Therefore, it is possible to prevent the tube member 4 from being damaged when the inner end plate 2 and the tube member 6 are thermally expanded.

  FIG. 5 is a cross-sectional view showing a heat insulating lid structure having a configuration in which the tube member does not have a curved surface portion. FIG. 6 is a cross-sectional view showing a state of the heat insulating lid structure 10 shown in FIG. As shown in FIG. 5, the heat insulating lid structure 10 includes an inner end plate 2, an outer end plate 3, and a tubular member 18.

  As shown in FIG. 5, the tubular member 18 includes a tube member 16, a tube member 7, and a tube member 4. In the heat insulation lid structure 10 shown in FIGS. 5 and 6, the heat insulation lid shown in FIG. 1 except that the pipe member 16 has a corner 16e (in other words, the curved surface portion 6d (see FIG. 1) is not provided). Since it is the same as that of the structure 1, a duplicate description is omitted. The tube member 16 is an annular member having an inner diameter and an outer diameter that are constant in the x-axis direction, that is, a plate thickness in the radial direction is constant.

  As shown in FIG. 6, when the inner end plate 2 and the tube member 16 are thermally expanded, the tube member 4 is joined to the tube member 16 and the tube member 7. The tube member 16 expands outward in the radial direction as the tube member 16 expands. At this time, the corner 16 e of the pipe member 16 hits the inner peripheral surface of the pipe member 4. As a result, a large stress acts on a part of the pipe member 4. Therefore, in the heat insulation lid structure 10 shown in FIG. 5, FIG. 6, there exists a possibility that the pipe member 4 may be damaged at the time of thermal expansion.

  On the other hand, in the heat insulating lid structure 1 shown in FIGS. 1 and 4, since the curved surface portion 6d is formed on the tube member 6, one point of stress acting on the tube member 4 from the tube member 6 at the time of thermal expansion. It is possible to suppress concentration on the screen. Therefore, it is possible to prevent the tube member 4 from being damaged when the inner end plate 2 and the tube member 6 are thermally expanded.

  With the invention according to the present embodiment described above, a heat insulating lid structure having high heat insulating performance and easy to manufacture can be provided.

  Note that the present invention is not limited to the above-described embodiment, and can be changed as appropriate without departing from the spirit of the present invention. For example, the case where the present invention is applied to a lid for a heating furnace that maintains the internal temperature has been described above. However, the present invention can be applied to any technique as long as the heat insulating member maintains the internal temperature.

  Although the present invention has been described with reference to the above embodiment, the present invention is not limited only to the configuration of the above embodiment, and within the scope of the invention of the claims of the present application. It goes without saying that various modifications, corrections, and combinations that can be made by those skilled in the art are included.

1, 10, 100 Thermal insulation cover structure 2, 102 Inner end plate 3, 103 Outer end plate 4, 104 Tube member 5 Space 6, 16 Tube member 6b, 106b Welding position 6c Welding position 6d Curved portion 16e Angle 7 Tube member 7b, 107b Welding position 7c Welding position 8, 18 Tubular member

Claims (1)

The inner end plate,
An outer end plate located outside the inner end plate;
A tubular member that is welded to the inner end plate and the outer end plate and forms a sealed space in a decompressed state together with the inner end plate and the outer end plate;
The tubular member is
A first pipe member welded to an end of the inner end plate;
A second pipe member welded to an end of the outer end plate;
A third pipe member welded to the first pipe member and the second pipe member,
The thickness of the third tube member is thinner than the thickness of the inner end plate, the first tube member, the outer end plate, and the second tube member,
In the first pipe member, the outer diameter of the first pipe member decreases from the welding position between the first pipe member and the third pipe member toward the welding position between the first pipe member and the inner end plate. Having a shape,
Thermal insulation lid structure.

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