A welded structure of a dewar shell and an insulator

Abstract

The utility model relates to a kind of welding structure of dewar shell and insulator, comprising: dewar shell, the sidewall of dewar shell is equipped with multiple round-taipyh's welding hole, and along the first direction is big down small structure, the inner wall of welding hole is equipped with accommodation groove, and accommodation groove coincides with the axis of the welding hole;Insulator, is in the welding hole, welding seam is formed between insulator and the inner wall of welding hole, and the insulator is fixed in the welding hole by solder.The welding hole is set as round-taipyh, so that the welding seam between welding hole and insulator gradually decreases, accommodation groove is set on the inner wall of welding hole, when brazing, the solder of molten assembly platform flows into welding seam, due to the siphon effect of welding seam itself, solder will accelerate to flow into welding seam, fill accommodation groove, realize that insulator is brazed in welding hole, avoid the problem that welding seam gap between welding hole and insulator is difficult to control under the condition of conventional cylindrical welding hole, so that welding yield is low.

Description

Technical Field

[0001] This utility model relates to the field of Dewar technology, and in particular to a welding structure between a Dewar shell and an insulator. Background Technology

[0002] In actual welding processes, the welding hole and insulator are typically assembled, and then the insulator and Dewar shell are placed vertically along the insulator axis, allowing the brazing solder to flow along the weld seam under its own weight. However, the welding hole on a conventional Dewar shell is a standard cylindrical shape, and the solder flows very quickly during welding. If the gap between the insulator and the welding hole, as well as the temperature rise curve, are not properly controlled, the melted solder will rapidly flow downwards along the weld seam. Within the space where the weld seam is about to form, the solder has no significant external resistance. As it flows downwards, the uneven surface roughness of the insulator and the inner wall of the welding hole creates different flow resistances, easily causing voids to form in the gap between the insulator and the inner wall of the welding hole where solder was originally present. This affects the brazing leakage rate and yield. Therefore, a welding structure for the Dewar shell and insulator is proposed. Utility Model Content

[0003] This utility model provides a welding structure for the Dewar shell and the insulator, which solves at least one of the above-mentioned technical problems.

[0004] This utility model provides a welding structure for a Dewar shell and an insulator, comprising:

[0005] The Dewar shell has multiple welding holes on its side wall. The welding holes are frustum-shaped and have a structure that is larger at the top and smaller at the bottom along a first direction. The inner wall of the welding hole has a receiving groove, and the receiving groove coincides with the axis of the welding hole.

[0006] An insulator is disposed within the welding hole, and a weld is formed between the insulator and the inner wall of the welding hole. The insulator is fixed within the welding hole by solder.

[0007] In one embodiment, each of the weld holes has an overflow positioning groove at one end near the outer side wall of the Dewar shell, the overflow positioning groove being used to restrain the solder remaining on the outer surface of the Dewar shell.

[0008] In one embodiment, the angle between the generatrix of the frustum-shaped welding hole and the axis ranges from 5°±2°.

[0009] In one embodiment, the insulator includes a lead wire and a ceramic ring, the ceramic ring being sleeved on the lead wire.

[0010] In one embodiment, the inner diameter of the large end of the welding hole is greater than the diameter of the ceramic ring, and the inner diameter of the small end of the welding hole is equal to the diameter of the ceramic ring, so that the weld is formed between the inner wall of the welding hole and the ceramic ring.

[0011] In one embodiment, the axial cross-section of the receiving groove is triangular, square, rectangular, semi-circular, or arc-shaped.

[0012] In one embodiment, the first direction is the direction perpendicular to the ground after the insulator is placed in the welding hole.

[0013] In one embodiment, the overflow positioning groove coincides with the axis of the welding hole, and the inner diameter of the overflow positioning groove is greater than or equal to the inner diameter of the welding hole.

[0014] In one embodiment, the Dewar shell is cylindrical and has edges at both ends.

[0015] In one embodiment, the surface of the Dewar shell is plated with a dark nickel layer.

[0016] Compared with the prior art, the advantages of this utility model are that the welding hole is set as a frustum shape, so that the weld between the welding hole and the insulator gradually decreases. A receiving groove is set on the inner wall of the welding hole. During brazing, the molten solder flows into the weld. Due to the siphon effect of the weld itself, the solder will accelerate to flow into the weld and gradually fill the receiving groove, thus brazing the insulator into the welding hole. This avoids the problem of low welding yield caused by the difficulty in controlling the weld gap between the welding hole and the insulator in the case of conventional cylindrical welding holes. Attached Figure Description

[0017] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings.

[0018] Figure 1 This is a cross-sectional view of the insulator and Dewar housing installation in the prior art;

[0019] Figure 2 This is a schematic diagram of the overall structure of this utility model;

[0020] Figure 3 This is a cross-sectional view of the overall structure of this utility model;

[0021] Figure 4 This is a cross-sectional view of the Dewar shell;

[0022] Figure 5 yes Figure 3 A schematic diagram of part A;

[0023] Figure 6 yes Figure 4A schematic diagram of Part B;

[0024] Figure 7 This is a schematic diagram of the solder ring and the insulator;

[0025] Figure 8 yes Figure 2 Side view;

[0026] Figure label:

[0027] 1. Dewar shell; 101. Edge; 2. Insulator; 201. Lead wire; 202. Ceramic ring; 3. Overflow positioning groove; 4. Welding hole; 5. Retention groove; 6. Solder ring; 7. Weld. Detailed Implementation

[0028] The present invention will be further described below with reference to the accompanying drawings.

[0029] When brazing insulators to the Dewar flask shell, a precise match is required between the insulator's ceramic ring and the welding hole. The clearance between the ceramic ring and the welding hole must be precisely controlled to ensure that the solder flows smoothly through this clearance and forms a brazed weld. This process presents a high level of difficulty in matching the insulator and the welding hole. Conventional welding holes on Dewar flask shells are cylindrical, such as... Figure 1 As shown, Figure 1 a is a cross-sectional view of the insulator after it has been installed with a conventional Dewar housing. Figure 1 b is a cross-sectional view of a standard Dewar assemblies. In this case, the solder flows quickly, and the uneven surface roughness between the outer surface of the insulator's ceramic ring and the inner wall of the welding hole causes different solder flow resistances. This easily leads to voids forming in the weld between the insulator's ceramic ring and the welding hole, affecting the brazing leak rate and yield. If the voids are too large, the leak rate will be unacceptable. If the voids are too small, even if the leak rate is acceptable for a short time after brazing, smaller voids can easily form new leakage points as the ambient temperature changes, increasing the risk of leak failure of the Dewar assembly.

[0030] Meanwhile, during brazing of the upper insulator, the solder ring is placed on the outer surface of the Dewar shell. During welding, the melting solder forms irregular weld spots on the outer surface, affecting the appearance quality. Furthermore, during welding of the lower insulator, the solder flows downwards due to gravity, reaching the outer surface of the Dewar shell and forming irregular weld spots due to overflow. This consumes some solder, resulting in insufficient solder flowing to the weld seam, further exacerbating the poor solder flow at the weld seam and leading to a low welding yield. Therefore, an overflow positioning groove is set at one end of the welding hole located on the outer surface of the Dewar shell. This ensures that the solder remains within the overflow positioning groove, forming regular circular weld spots, which is aesthetically pleasing and prevents the solder from flowing freely on the outer surface of the Dewar shell.

[0031] Please refer to Figures 2 to 8This utility model provides a welding structure for a Dewar shell and an insulator, comprising: a Dewar shell 1 and an insulator 2. The surface of the Dewar shell 1 is plated with a dark nickel layer. Multiple welding holes 4 are provided on the sidewall of the Dewar shell 1. The welding holes 4 are frustoconical and have a structure that is larger at the top and smaller at the bottom along a first direction. During brazing, the end with the larger opening diameter faces upwards. Multiple accommodating grooves 5 are provided on the inner wall of the welding holes 4, and the accommodating grooves 5 coincide with the axis of the welding holes 4. When the solder melts and flows downwards along the weld seam 7, it preferentially flows along the interior of the accommodating groove 5, forming an annular solder-filled area. Simultaneously, the solder continues to flow downwards until a complete weld seam 7 is formed. The solder-filled area formed by the accommodating groove 5 has a better leakage rate index, effectively improving the welding leakage rate technology level. The insulator 2 is disposed within the welding holes 4 and fixed within the welding holes 4 by solder.

[0032] To better implement this utility model, refer to Figures 3 to 6 In one embodiment, each welding hole 4 is provided with an overflow positioning groove 3 at one end near the outer side wall of the Dewar housing 1. The overflow positioning groove 3 is used to constrain the solder remaining on the outer surface of the Dewar housing 1.

[0033] To better implement this utility model, refer to Figure 6 In one embodiment, the angle between the generatrix of the frustum-shaped welding hole 4 and the axis is 5°±2°, that is, the angle α is 3°≤α≤7°. In this embodiment, the angle is preferably 5°.

[0034] To better implement this utility model, refer to Figure 7 In one embodiment, Figure 7 In section b, insulator 2 includes lead wire 201 and ceramic ring 202. The outer surface of ceramic ring 202 is coated with a paste, usually nickel-coated, mainly for brazing. Ceramic ring 202 is fitted onto lead wire 201. The inner diameter of the large end of welding hole 4 is larger than the diameter of ceramic ring 202, and the inner diameter of the small end of welding hole 4 is equal to the diameter of ceramic ring 202, so that a weld 7 is formed between the inner wall of welding hole 4 and ceramic ring 202.

[0035] To better implement this utility model, refer to Figure 6 In one embodiment, the axial cross-section of the receiving groove 5 is triangular, square, rectangular, semi-circular, or arc-shaped. In this embodiment, a triangular shape is preferred.

[0036] To better implement this utility model, refer to Figure 2 and Figure 8 In one embodiment, the first direction is the direction perpendicular to the ground after the insulator 2 is disposed in the welding hole 4.

[0037] To better implement this utility model, refer to Figure 5 As shown, in one embodiment, the overflow positioning groove 3 coincides with the axis of the welding hole 4, and the inner diameter of the overflow positioning groove 3 is greater than or equal to the inner diameter of the welding hole 4.

[0038] To better implement this utility model, refer to Figure 3 and Figure 4 In one embodiment, the Dewar shell 1 is cylindrical and has edges 101 at both ends.

[0039] The Dewar outer shell 1 may have one welding hole 4 or two welding holes 4, depending on the actual situation.

[0040] When only one welding hole 4 is provided on the Dewar outer shell 1, during the brazing of the Dewar outer shell 1 and the insulator 2, the lead wire 201 of the insulator 2 inside the welding hole 4 is vertically oriented towards the first direction. At this time, the end of the welding hole 4 with a larger diameter is close to the outer wall of the Dewar outer shell 1, and the end with a smaller diameter is close to the inner wall of the Dewar outer shell 1. Figure 7 The solder ring 6 shown in Figure a is... Figure 2 The solder ring 6 is placed on the overflow positioning groove 3 for welding. The melted solder ring 6 flows into the weld seam 7 between the inner wall of the welding hole 4 and the ceramic ring 202 of the insulator 2, filling the receiving groove 5 until the weld seam 7 is completely filled. During the process of the solder flowing into the weld seam 7, due to the siphon effect of the weld seam 7 itself, the liquid solder will preferentially accelerate into the weld seam 7. The excess completely melted solder will not flow directly downward with gravity on the outer surface of the Dewar shell 1 due to the effect of the overflow positioning groove 3, ensuring that the solder flows towards the weld seam 7. After the brazing is completed, a circular weld spot with the same shape as the overflow positioning groove 3 is finally formed on the outer surface of the Dewar shell 1.

[0041] When the Dewar outer shell 1 has two welding holes 4, the axial positions of the two welding holes 4 are the same. During brazing, one welding hole 4 is on top and the other welding hole 4 is on the bottom, as shown below. Figure 2 As shown, the diameters of both welding holes 4 gradually decrease from top to bottom, meaning that the two welding holes 4 face the same direction. Welding is performed simultaneously on both welding holes 4. During welding, the solder ring 6 of the lower welding hole 4 is positioned on the surface of the end with the larger diameter, i.e., inside the Dewar shell 1. During brazing, the molten solder will flow along the weld seam 7 formed between the ceramic ring 202 of the insulator 2 and the inner wall of the welding hole 4, filling the receiving groove 5, and ultimately forming a circular weld spot on the outer surface of the Dewar shell 1 that matches the shape of the overflow positioning groove 3.

[0042] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A welded structure for a Dewar shell and an insulator, characterized in that, include: The Dewar shell has multiple welding holes on its side wall. The welding holes are frustum-shaped and have a structure that is larger at the top and smaller at the bottom along a first direction. The inner wall of the welding hole has a receiving groove, and the receiving groove coincides with the axis of the welding hole. An insulator is disposed within the welding hole, and a weld is formed between the insulator and the inner wall of the welding hole. The insulator is fixed within the welding hole by solder.

2. The welding structure of the Dewar shell and the insulator according to claim 1, characterized in that, Each of the weld holes has an overflow positioning groove at one end near the outer side wall of the Dewar shell, the overflow positioning groove being used to restrain the solder remaining on the outer surface of the Dewar shell.

3. The welding structure of the Dewar shell and the insulator according to claim 1 or 2, characterized in that, The angle between the generatrix of the frustum-shaped welding hole and the axis is within the range of 5°±2°.

4. The welding structure of the Dewar shell and the insulator according to claim 1, characterized in that, The insulator includes a lead wire and a ceramic ring, with the ceramic ring sleeved on the lead wire.

5. The welding structure of the Dewar shell and the insulator according to claim 4, characterized in that, The inner diameter of the larger end of the welding hole is greater than the diameter of the ceramic ring, and the inner diameter of the smaller end of the welding hole is equal to the diameter of the ceramic ring, so that the weld is formed between the inner wall of the welding hole and the ceramic ring.

6. The welding structure of the Dewar shell and the insulator according to claim 1, characterized in that, The axial cross-section of the accommodating groove is triangular, square, rectangular, semi-circular, or arc-shaped.

7. The welding structure of the Dewar shell and the insulator according to claim 1, characterized in that, The first direction is the direction perpendicular to the ground after the insulator is installed in the welding hole.

8. The welding structure of the Dewar shell and the insulator according to claim 2, characterized in that, The overflow positioning groove coincides with the axis of the welding hole, and the inner diameter of the overflow positioning groove is greater than or equal to the inner diameter of the welding hole.

9. The welding structure of the Dewar shell and the insulator according to claim 1, characterized in that, The Dewar shell is cylindrical and has edges at both ends.

10. The welding structure of the Dewar shell and the insulator according to claim 4, characterized in that, The surface of the Dewar shell is plated with a dark nickel layer.

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