End plug for cladding tube welding
By designing the welding boss, groove, and venting groove structure of the end plug, the problems of burn-through and gas expansion during TIG welding of ultra-thin-walled cladding tubes were solved, achieving efficient and damage-free welding results and improving the reliability and production efficiency of single-rod assemblies.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- CHENGDU CAIC ELECTRONICS CO LTD
- Filing Date
- 2025-06-17
- Publication Date
- 2026-05-29
AI Technical Summary
Existing TIG welding methods are prone to weld burn-through, gas expansion, and difficulty in controlling weld reinforcement when welding ultra-thin wall cladding tubes, which affects assembly and results in low production efficiency.
Design an end plug for welding cladding tubes, including an end plug handle, a welding boss, a tapered cladding tube guide section, and a venting groove. By adjusting the welding angle and position, and utilizing the welding boss and groove structure, direct welding of the cladding tube can be avoided. The venting groove is set to balance the internal and external pressures, thereby achieving effective welding.
It solves the problems of weld burn-through and gas expansion, improves welding efficiency, reduces the risk of post-weld processing damage, ensures that the weld is flat and without protrusions, and improves welding quality and safety.
Smart Images
Figure CN224294911U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of cladding tube welding technology, specifically relating to an end plug for cladding tube welding. Background Technology
[0002] As an indispensable and important component within the reactor, the single rod is mainly constructed by welding together a stainless steel cladding tube and upper and lower end plugs. The main requirements for the welds between the cladding tube and the end plugs are as follows:
[0003] 1. The weld must have reliable sealing performance to avoid leakage that could cause significant damage;
[0004] 2. The weld must have a certain penetration depth, with a penetration depth greater than 90% of the cladding pipe wall thickness; and defects such as cracks, pinholes, and slag inclusions are not allowed in the weld.
[0005] 3. The weld surface should be smooth and flat, and there should be no protrusions;
[0006] Currently, TIG welding is a primary welding method for this single rod. However, when welding ultra-thin walls (≤0.5mm), the weld surface is prone to protrusions, and the weld reinforcement is difficult to control, affecting subsequent assembly of the experimental element. Furthermore, due to the high heat input, the cladding tube is easily burned through during welding, resulting in incomplete weld formation and extremely low production efficiency. Moreover, the traditional weld structure is a closed structure, with welding heat transferred along the cladding tube. Localized thermal expansion of the gas compresses the softened metal, and the gas generated in the gap between the tube wall and the end plug cannot escape, leading to gas expansion problems at the root of the cladding tube and end plug mating area.
[0007] Therefore, it is of great significance to develop a welding structure and welding method suitable for cladding tubes and end plugs. Utility Model Content
[0008] Based on the problems existing in the background technology, this utility model proposes an end plug for welding cladding tubes, which solves the problems of easy burn-through and gas expansion of the weld when welding cladding tubes using the existing TIG welding method.
[0009] The embodiments of this utility model are implemented as follows:
[0010] This utility model provides an end plug for welding a cladding tube, comprising an end plug shank, a welding boss, and a tapered cladding tube guide section coaxially and fixedly connected in sequence. The end plug shank, welding boss, and tapered cladding tube guide section are all of a rotary body structure. The diameter of the end plug shank is smaller than the diameter of the welding boss, and the diameter of the welding boss is larger than the inner diameter of the cladding tube. A welding step is provided on the end face of the welding boss away from the end plug shank. The diameter of the welding step is the same as the outer diameter of the cladding tube. The tapered cladding tube guide section is provided on the end face of the welding step. The large-diameter end of the tapered cladding tube guide section is fixedly connected to the end face of the welding step. The diameter of the large-diameter end of the tapered cladding tube guide section is smaller than the diameter of the welding step, and the diameter of the small-diameter end of the tapered cladding tube guide section is smaller than the inner diameter of the cladding tube.
[0011] A venting groove is provided between the welding step and the guide section of the cladding tube, and the length direction of the venting groove is in the same direction as the axis of the entire end plug.
[0012] Furthermore, a transition section is coaxially provided between the end plug shank and the welding boss.
[0013] Furthermore, a welding groove is provided circumferentially between the transition section and the welding boss.
[0014] Furthermore, the length of the welding step is L4, where L4 = 0.3 mm to 0.4 mm.
[0015] Furthermore, the diameter of the welding boss is D3, where D3 = D2 + 0.4 mm to 0.5 mm, and D2 is the diameter of the welding step or the outer diameter of the cladding tube; the length of the welding boss is L3, where L3 = 0.3 to 0.4 mm.
[0016] Furthermore, the diameter of the welding groove is D4, and the range of D4 is 0 < D4 ≤ D2 - 0.4 mm, where D2 is the diameter of the welding step or the outer diameter of the cladding tube; the length of the welding groove is L2, and L2 = 0.3 mm to 0.4 mm.
[0017] Furthermore, the length of the ventilation groove is L5, L5 = 1m ~ 2mm; the width of the ventilation groove is H1, H1 = 0.5mm ~ 0.8mm; and the height of the ventilation groove is H2, H2 = 0.3mm ~ 0.5mm.
[0018] Furthermore, the difference between the large-diameter end and the small-diameter end of the tapered cladding tube guide section is greater than 0.5 mm.
[0019] The welding method for the end plug used in welding the cladding tube provided by this utility model is as follows:
[0020] Step 1: Clean the casing tube and the entire end plug with anhydrous ethanol to ensure that there is no oil or other residue at the welding location.
[0021] Step 2: Place the cladding tube through the tapered cladding tube guide section to tightly fit the end face of the cladding tube against the stepped surface of the welding step;
[0022] Step 3: Horizontally clamp the assembled end plug and casing tube onto the rotary positioner;
[0023] Step 4: Align the tungsten electrode of the TIG welding torch with the welding step of the cladding tube, with the tungsten electrode at an angle of 80°-85° to the horizontal.
[0024] Step 5: Start the positioner to rotate. When the tungsten electrode is aligned with the edge of the venting groove, start the arc welding and finish the welding by using the venting groove as the arc termination point.
[0025] In the above welding method, aligning the tungsten electrode of the welding torch with the welding boss solves the burn-through problem that easily occurs during the welding of the cladding tube. By aligning the tungsten electrode with the welding boss instead of the traditional weld gap, the problem of the welding arc directly targeting the cladding tube and causing burn-through is avoided. After melting, the welding boss, welding groove, transition section, and cladding tube form the weld. The venting groove connects the cladding tube to the external environment, thus ensuring the pressure inside and outside the cladding tube during welding and preventing defects such as gas expansion.
[0026] The beneficial effects of this utility model are as follows: The end plug for welding cladding tubes provided by this utility model solves the problem of cladding tubes being prone to burn-through due to the large heat input of TIG welding by designing a welding boss. The design of the welding groove avoids weld protrusion, solving the problem of weld seam not forming properly after welding and affecting assembly. Furthermore, no further grinding is required after welding, reducing the probability of damage to the cladding tube due to grinding and thus greatly reducing the risk of failure during the use of the cladding tube. The venting groove balances the air pressure inside and outside the cladding tube at the weld seam position during welding, solving the problem of easy air expansion defects. Attached Figure Description
[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The above and other objects, features, and advantages of this utility model will become clearer through the drawings. The same reference numerals indicate the same parts in all the drawings. The drawings are not intentionally drawn to scale to actual dimensions; the focus is on illustrating the main idea of this utility model.
[0028] Figure 1 This is a cross-sectional schematic diagram of an end plug for welding a casing tube.
[0029] Figure 2This is a schematic diagram showing the dimensions and structure of an end plug for welding a cladding tube.
[0030] Figure 3 for Figure 1 A magnified structural diagram of point A in the middle.
[0031] Figure 4 This is a schematic diagram of the assembly structure of the casing tube and the end plug.
[0032] Figure 5 for Figure 4 A magnified structural diagram at point B in the middle.
[0033] Figure 6 for Figure 4 A magnified structural diagram at point C.
[0034] Among them, 1. tapered cladding tube guide section; 2. welding step; 3. welding boss; 4. welding groove; 5. transition section; 6. end plug handle; 7. vent groove; 8. cladding tube. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0036] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0037] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0038] Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.
[0039] Please refer to Figures 1-6As shown, this utility model provides an end plug for welding a cladding tube, comprising an end plug handle 6, a welding boss 3, and a tapered cladding tube guide section 1, which are coaxially and fixedly connected in sequence. The end plug handle 6, welding boss 3, and tapered cladding tube guide section 1 all have a rotary structure. The diameter of the end plug handle 6 is smaller than the diameter of the welding boss 3, and the diameter of the welding boss 3 is larger than the inner diameter of the cladding tube 8. A welding step 2 is provided on the end face of the welding boss 3 away from the end plug handle 6, and the diameter of the welding step 2 is equal to the diameter of the cladding tube. The outer diameters of the two end plugs are the same. The tapered cladding tube guide section 1 is provided on the end face of the welding step 2. The large diameter end of the tapered cladding tube guide section 1 is fixedly connected to the end face of the welding step 2. The diameter of the large diameter end of the tapered cladding tube guide section 1 is smaller than the diameter of the welding step 2. The diameter of the small diameter end of the tapered cladding tube guide section 1 is smaller than the inner diameter of the cladding tube 8. A venting groove 7 is provided between the welding step 2 and the tapered cladding tube guide section 1. The length direction of the venting groove 7 is in the same direction as the axis of the entire end plug.
[0040] Furthermore, a transition section 5 is coaxially provided between the end plug shank 6 and the welding boss 3, and the length of the transition section 5 is L1, where L1≥0mm.
[0041] Furthermore, a welding groove 4 is provided circumferentially between the transition section 5 and the welding boss 3.
[0042] Furthermore, the length of the welding step 2 is L4, where L4 = 0.3 mm to 0.4 mm.
[0043] Furthermore, the diameter of the welding boss 3 is D3, where D3 = D2 + 0.4 mm to 0.5 mm, and D2 is the diameter of the welding step 2 or the outer diameter of the casing tube 8; the length of the welding boss 3 is L3, where L3 = 0.3 to 0.4 mm.
[0044] Furthermore, the diameter of the welding groove 4 is D4, and the range of D4 is 0 < D4 ≤ D2 - 0.4 mm, where D2 is the diameter of the welding step 2 or the outer diameter of the casing tube 8; the length of the welding groove 4 is L2, and L2 = 0.3 mm to 0.4 mm.
[0045] Furthermore, the length of the ventilation groove 7 is L5, L5 = 1m ~ 2mm; the width of the ventilation groove 7 is H1, H1 = 0.5mm ~ 0.8mm; and the height of the ventilation groove 7 is H2, H2 = 0.3mm ~ 0.5mm.
[0046] Furthermore, the difference between the large-diameter end and the small-diameter end of the tapered cladding tube guide section 1 is greater than 0.5 mm.
[0047] Specifically, as a specific configuration of the entire end plug, when the material of the entire end plug is 06Cr17Ni12Mo2 and the specification of the cladding tube 8 is φ8.17×0.2,
[0048] The length of welding step 2 is 0.35 mm. The circumferential diameter of welding boss 3 is 8.6 mm; the circumferential diameter of welding groove 4 is 6.2 mm; the length of welding groove 4 is 0.35 mm; the diameter of transition section 5 is inconsistent with the circumferential diameter of welding step 2, and the diameter of transition section 5 is the same as the circumferential diameter of groove; the circumferential diameter of welding step 2 is consistent with the outer diameter of cladding tube 8, the diameter of welding step 2 is 8.17 mm, the length of transition section 5 is 0 mm, the length of venting groove 7 is 2 mm, the width of venting groove 7 is 0.6 mm, and the height of venting groove 7 is 0.4 mm; the difference between the large-diameter end diameter D2 and the small-diameter end diameter D1 of the tapered cladding tube guide section 1 is greater than 0.5 mm.
[0049] The welding method for the end plug used in welding the cladding tube provided by this utility model is as follows:
[0050] Step 1: Clean the casing tube 8 and the entire end plug with anhydrous ethanol to ensure that there is no oil or other residue at the welding location.
[0051] Step 2: The end face of the cladding tube 8 is pressed tightly against the stepped surface of the welding step 2 by passing it through the tapered cladding tube guide section 1;
[0052] Step 3: Horizontally clamp the assembled end plug and the casing tube 8 onto the rotary positioner;
[0053] Step 4: Align the tungsten electrode of the TIG welding torch with the welding step 2, with the tungsten electrode at an angle of 80°-85° to the horizontal.
[0054] Step 5: Start the positioner to rotate. When the tungsten electrode is aligned with the edge of the venting groove 7, start the arc welding and finish the welding with the venting groove 7 as the arc termination point.
[0055] In the above welding method, the tungsten electrode of the welding torch is aligned with the welding boss 3, which solves the problem of burn-through that easily occurs during the welding of the cladding tube 8. By aligning the tungsten electrode with the welding boss 3 instead of the traditional weld gap, the problem of the welding arc directly aligning with the cladding tube 8, which would cause burn-through, is avoided. After welding melting, the welding boss 3, welding groove 4, transition section 5, and cladding tube 8 form a weld. The venting groove 7 connects the cladding tube 8 to the external environment, thus ensuring the internal and external pressure of the cladding tube 8 during welding and preventing defects such as gas expansion.
[0056] The beneficial effects of this utility model are as follows: The end plug for welding a cladding tube provided by this utility model solves the problem of the cladding tube being prone to burn-through due to the large heat input of TIG welding by designing the welding boss 3. The design of the welding groove 4 avoids weld protrusion, solving the problem that the weld is not easy to form after welding and affects assembly. Therefore, no further grinding is required after welding, reducing the probability of damage to the cladding tube 8 due to grinding and processing, and thus greatly reducing the risk of failure of the cladding tube 8 during use. The vent groove 7 balances the internal and external air pressure of the cladding tube 8 at the weld position during welding, solving the problem of easy air expansion defects.
[0057] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. An end plug for welding a cladding tube, characterized in that, The device includes an end plug shank, a welding boss, and a tapered cladding tube guide section that are coaxially and fixedly connected in sequence. The end plug shank, welding boss, and tapered cladding tube guide section are all rotary structures. The diameter of the end plug shank is smaller than the diameter of the welding boss, and the diameter of the welding boss is larger than the inner diameter of the cladding tube. A welding step is provided on the end face of the welding boss away from the end plug shank. The diameter of the welding step is the same as the outer diameter of the cladding tube. The tapered cladding tube guide section is provided on the end face of the welding step. The large-diameter end of the tapered cladding tube guide section is fixedly connected to the end face of the welding step. The diameter of the large-diameter end of the tapered cladding tube guide section is smaller than the diameter of the welding step, and the diameter of the small-diameter end of the tapered cladding tube guide section is smaller than the inner diameter of the cladding tube. A venting groove is provided between the welding step and the guide section of the cladding tube, and the length direction of the venting groove is in the same direction as the axis of the entire end plug.
2. The end plug for welding a cladding tube according to claim 1, characterized in that, A transition section is coaxially provided between the end plug shank and the welding boss.
3. The end plug for welding a cladding tube according to claim 2, characterized in that, A welding groove is provided circumferentially between the transition section and the welding boss.
4. The end plug for welding a cladding tube according to claim 3, characterized in that, The length of the welding step is L4, where L4 = 0.3 mm to 0.4 mm.
5. The end plug for welding a cladding tube according to claim 4, characterized in that, The diameter of the welding boss is D3, where D3 = D2 + 0.4 mm to 0.5 mm, and D2 is the diameter of the welding step or the outer diameter of the cladding tube; the length of the welding boss is L3, where L3 = 0.3 to 0.4 mm.
6. The end plug for welding a cladding tube according to claim 5, characterized in that, The diameter of the welding groove is D4, and the range of D4 is 0 < D4 ≤ D2 - 0.4 mm, where D2 is the diameter of the welding step or the outer diameter of the cladding tube; the length of the welding groove is L2, and L2 = 0.3 mm to 0.4 mm.
7. The end plug for welding a cladding tube according to claim 6, characterized in that, The length of the ventilation groove is L5, L5 = 1m ~ 2mm; the width of the ventilation groove is H1, H1 = 0.5mm ~ 0.8mm; and the height of the ventilation groove is H2, H2 = 0.3mm ~ 0.5mm.
8. The end plug for welding a cladding tube according to claim 7, characterized in that, The difference between the large-diameter end and the small-diameter end of the tapered cladding tube guide section is greater than 0.5 mm.