Expanding and necking pipeline for preventing capillary tube from being blocked by welding

Abstract

The pipeline comprises a first flaring section, a first reducing section, a necking section, a second reducing section, a second flaring section, a third reducing section and the capillary tube which are sequentially connected from top to bottom in the axial direction. The first flaring section is connected with the first reducing section to form an upper end leading-in opening structure; the lower end of the first reducing section is connected with the necking section, and the inner diameter of the necking section is smaller than the outer diameter of the capillary tube to form a diameter limiting channel; the second reducing section is arranged below the necking section and is used for limiting the insertion depth of the capillary tube and providing a first resistance welding function; the second flaring section is arranged between the second reducing section and the third reducing section, the inner diameter of the second flaring section is larger than the outer diameter of the capillary tube, and the second flaring section can be in clearance fit with the capillary tube and provide a second resistance welding function; and the third reducing section is arranged at the bottom of the expanding and necking pipeline and is used for forming a welding site, receiving the welding flux and providing a third resistance welding function. Through the arrangement, the reliability of pipeline welding is higher.

Description

TECHNICAL FIELD

[0001] The utility model relates to air conditioning equipment manufacturing technical field especially relates to a kind of for capillary tube anti-welding plug expansion and contraction pipe line. BACKGROUND

[0002] Capillary tube is the throttling and shunt element commonly used in heat pump air conditioning refrigeration system. Its pipe diameter is very small, and welding is prone to welding plug, causing poor circulation of refrigerant. Slight welding plug can make system pressure rise, and refrigeration effect becomes poor, and serious welding plug can even lead to air conditioner unable to operate normally.

[0003] The common practice at present is to weld capillary tube with other pipe lines through variable diameter structure, but due to small pipe diameter, difficult insertion and unstable welding, solder is prone to flow into capillary tube, causing welding plug. At the same time, the insertion depth is not easy to control when the worker operates, which can also lead to pipe mouth loosening or welding failure. UTILITY MODEL CONTENT

[0004] In order to solve the problems of the prior art, the utility model aims to provide an expansion and contraction pipe line for preventing capillary tube from welding plug. The device can improve the reliability of expansion and contraction pipe line welding.

[0005] In order to achieve the above purpose, the utility model adopts the following technical scheme:

[0006] An expansion and contraction pipe line for preventing capillary tube from welding plug comprises: a first expansion section, a first variable diameter section, a contraction section, a second variable diameter section, a second expansion section and a capillary tube connected in sequence from top to bottom along the axial direction; the first expansion section is connected with the first variable diameter section to form an upper end inlet structure; the lower end of the first variable diameter section is connected with the contraction section, and the inner diameter of the contraction section is smaller than the outer diameter of the capillary tube to form a diameter limiting channel; the second variable diameter section is arranged below the contraction section to limit the insertion depth of the capillary tube and provide a first welding prevention function; the second expansion section is arranged between the second variable diameter section and the third variable diameter section, and the inner diameter of the second expansion section is greater than the outer diameter of the capillary tube to gap fit with the capillary tube and provide a second welding prevention function; the third variable diameter section is arranged at the bottom of the expansion and contraction pipe line to form a welding site and receive solder, thereby providing a third welding prevention function.

[0007] Further, the outer diameter R4 of the capillary tube satisfies:

[0008] R4=R1×0.04+R2,

[0009] Wherein, R1 is the inner diameter of the first expansion section; R2 is the inner diameter of the contraction section.

[0010] Further, the radial distance between the lower end inner side bottom of the third variable diameter section and the capillary tube is greater than or equal to 0.1 mm and less than or equal to 0.2 mm.

[0011] Furthermore, the difference between the inner diameter R3 of the second flared section and the outer diameter R4 of the capillary is greater than or equal to 0.04 mm and less than or equal to 0.06 mm.

[0012] Furthermore, the difference between the inner diameter R2 of the constricted section and the outer diameter R4 of the capillary is greater than or equal to 0.08 mm and less than or equal to 0.12 mm.

[0013] Furthermore, the length of the second flared section is L1 = 6 - L2; where L2 is the active insertion control length, 0.4mm ≤ L2 ≤ 0.5mm.

[0014] Furthermore, the length of the constricted section L3 = (L4 + L5) / 2, and the length of the constricted section L3 after the capillary is inserted satisfies L3 = L6 - L2; where L4 is the total length of the first flared section and the first variable diameter section, L5 is the total length of the second flared section and the third variable diameter section, and L6 is the total length of the constricted section and the second variable diameter section.

[0015] Furthermore, the length of the constricted section is greater than or equal to the length of the second flared section, and the difference between the two is greater than or equal to 1.2 mm and less than or equal to 2.2 mm.

[0016] The aforementioned expansion and contraction pipe adopts a multi-segment expansion and contraction structure design, including a first expansion segment, a diameter-changing segment, a contraction segment, a second expansion segment, and a third diameter-changing segment. This makes the insertion between the capillary tube and the pipe more stable and the positioning more accurate. At the same time, it forms a multi-layered weld resistance structure, thereby effectively preventing the capillary tube from being blocked by solder flowing upwards, and improving the reliability and production efficiency of the refrigeration system welding. Attached Figure Description

[0017] Figure 1 This is a structural schematic diagram of the expansion and contraction pipe provided by this utility model;

[0018] Figure 2 This is a cross-sectional view of the expansion and contraction pipe provided by this utility model. Detailed Implementation

[0019] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0020] like Figure 1 and Figure 2As shown, this application provides a flared and constricted pipe for capillary anti-weld plugging, comprising: a first flared section 1, a first variable diameter section 2, a constricted section 3, a second variable diameter section 4, a second flared section 51, a third variable diameter section 6, and a capillary tube 7 connected sequentially from top to bottom along the axial direction.

[0021] Specifically, the first flared section 1 is connected to the first variable diameter section 2 to form an upper inlet structure; the lower end of the first variable diameter section 2 is connected to the constricted section 3, the inner diameter of the constricted section 3 being smaller than the outer diameter of the capillary tube 7, forming a diameter-limiting channel; the second variable diameter section 4 is located below the constricted section 3 to limit the insertion depth of the capillary tube 7 and provide a first weld resistance function; the second flared section 51 is located between the second variable diameter section 4 and the third variable diameter section 6, its inner diameter being larger than the outer diameter of the capillary tube 7, which can be clearance-fitted with the capillary tube 7 and provide a second weld resistance function; the third variable diameter section 6 is located at the bottom of the flared and constricted pipe to form a welding point and receive the solder, providing a third weld resistance function.

[0022] Through the above-described setup, guidance, positioning, and depth control of the capillary tube 7 insertion process are achieved, while a triple weld barrier is established, significantly reducing the risk of weld blockage caused by solder overflow. The structural design optimizes the connection method between the capillary tube 7 and other pipelines, improving the stability and operability of the welding process. Especially in conditions with small pipe diameters and limited welding space, this solution can significantly improve assembly efficiency and welding yield, thereby enhancing the overall operational reliability of the heat pump air conditioning system.

[0023] The outer diameter R4 of capillary tube 7 satisfies:

[0024] R4 = R1 × 0.04 + R2,

[0025] Wherein, R1 is the inner diameter of the first flared section 1; R2 is the inner diameter of the constricted section 3.

[0026] The above settings allow for a more rational connection between the capillary tube 7 and the expansion / contraction pipe, improving overall assembly accuracy and effectively avoiding problems such as poor insertion, welding misalignment, or weld failure caused by mismatched gaps. This enhances the adaptability and consistency of the structure and facilitates standardized welding procedures. Furthermore, this calculation formula can reduce process fluctuations caused by dimensional errors, enhancing the welding reliability and repeatability of the refrigeration system.

[0027] The radial distance between the inner bottom of the lower port of the third reducing section 6 and the capillary tube 7 is greater than or equal to 0.1 mm and less than or equal to 0.2 mm. This is to prevent the solder from flowing in easily due to excessive gaps in the pipe fittings or to make welding difficult due to insufficient gaps, thereby further improving welding consistency and weld quality.

[0028] The difference between the inner diameter R3 of the second flared section 51 and the outer diameter R4 of the capillary tube 7 is greater than or equal to 0.04 mm and less than or equal to 0.06 mm. This structure provides a second layer of solder resist protection, improving the accuracy and stability of solder flow control during welding. The appropriate gap design ensures the solder resist function while avoiding insertion difficulties caused by assembly errors, thus improving production consistency.

[0029] The difference between the inner diameter R2 of the constricted section 3 and the outer diameter R4 of the capillary tube 7 is greater than or equal to 0.08 mm and less than or equal to 0.12 mm. This gap setting enhances the constriction capability of the constricted section 3 in limiting the capillary tube 7 and provides the primary solder barrier function against solder migration. Controlling the gap within the range of 0.08 mm to 0.12 mm provides sufficient insertion force support and, through the adhesion to the hole wall, forms a liquid blocking boundary, enhancing the anti-solder plugging effect.

[0030] The length of the second flared section 51 is L1 = 6 - L2; where L2 is the active insertion control length, 0.4mm ≤ L2 ≤ 0.5mm. The length of the second flared section 51 must meet the requirements for smooth insertion with the capillary tube 7. This setting helps to prevent assembly damage and the accumulation of process errors.

[0031] The length L3 of the constricted section 3 is L3 = (L4 + L5) / 2. Considering the springback effect after thermal expansion and contraction of the pipeline, the length L3 of the constricted section 3 after the capillary tube 7 is inserted satisfies L3 = L6 - L2; where L4 is the total length of the first flared section 1 and the first diameter-changing section 2, L5 is the total length of the second flared section 51 and the third diameter-changing section 6, and L6 is the total length of the constricted section 3 and the second diameter-changing section 4. By balancing the dimensions of the upper and lower pipe sections, it is beneficial to achieve uniform heat distribution and stress balance during the welding process. Combined with the insertion control parameter L2 to set the length difference, the precise matching between the welding point position and the insertion depth of the capillary tube 7 can be further optimized. This parameter system based on global structural coordination improves structural consistency, process stability, and reliability of later maintenance.

[0032] The length of the constricted section 3 is greater than or equal to the length of the second flared section 51, and the difference between the two is greater than or equal to 1.2 mm and less than or equal to 2.2 mm. Appropriately lengthening the constricted section 3 can improve the limiting performance, enhance the rigid support of the capillary tube 7 insertion, and prevent loosening caused by insertion tilt or vibration; at the same time, the shorter second flared section 51 maintains good guide and solder blocking transition space, improving the overall welding reliability and process stability.

[0033] The above description of embodiments of the present invention, through which those skilled in the art are able to implement or use the present invention, will be readily apparent to those skilled in the art. Various modifications to these embodiments will be readily apparent to those skilled in the art. The general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein.

Claims

1. An expanding and reducing ported line for capillary tube solder stop, characterized by, The application relates to a capillary tube welding device. The first flared section (1) is connected with the first reducing section (2) to form an upper end guide inlet structure. The lower end of the first reducing section (2) is connected with the necked section (3), the inner diameter of the necked section (3) is smaller than the outer diameter of the capillary tube (7), and a diameter-limited channel is formed. The second reducing section (4) is arranged below the necked section (3) and is used for limiting the insertion depth of the capillary tube (7). The second flared section (5) is arranged between the second reducing section (4) and the third reducing section (6), the inner diameter of the second flared section (5) is larger than the outer diameter of the capillary tube (7), and the second flared section (5) can be matched with the capillary tube (7) in a gap mode. The lower end of the third reducing section (6) is arranged at the bottom of the flared and necked pipe and is used for forming a welding site and receiving welding material. The outer diameter R4 of the capillary tube (7) satisfies the following formula:

2. The flare and reducer line for capillary non-weld block as claimed in claim 1, characterized in that, R4 = R1 * 0.04 + R2, wherein R1 is the inner diameter of the first flared section (1), and R2 is the inner diameter of the necked section (3). The radial distance D between the lower end of the third reducing section (6) and the capillary tube (7) is greater than or equal to 0.1 mm and smaller than or equal to 0.2 mm.

3. The flare and reducer line for capillary non-weld block as claimed in claim 1, wherein, The difference between the inner diameter R3 of the second flared section (5) and the outer diameter R4 of the capillary tube (7) is greater than or equal to 0.04 mm and smaller than or equal to 0.06 mm.

4. The bell and spigot pipe for capillary non-welded joint according to claim 1, wherein The difference between the inner diameter R2 of the necked section (3) and the outer diameter R4 of the capillary tube (7) is greater than or equal to 0.08 mm and smaller than or equal to 0.12 mm.

5. The bell and spigot pipe for capillary tube solder stop according to claim 1, wherein The length L1 of the second flared section (5) is 6 mm-L2, wherein L2 is an active insertion control length, 0.4 mm<=L2<=0.5 mm.

6. The bell and spigot pipe for capillary tube solder stop according to claim 1, wherein The length L3 of the necked section (3) is (L4+L5) / 2, and the length of the necked section (3) after the capillary tube (7) is inserted satisfies L3=L6-L2; wherein L4 is the total length of the first flared section (1) and the first reducing section (2), L5 is the total length of the second flared section (5) and the third reducing section (6), and L6 is the total length of the necked section (3) and the second reducing section (4).

7. The bell and spigot pipe for capillary non-welded joints according to claim 6, characterized in that, The length of the necked section (3) is greater than or equal to the length of the second flared section (5), and the difference between the length of the necked section (3) and the length of the second flared section (5) is greater than or equal to 1.2 mm and smaller than or equal to 2.2 mm.

8. The bell and spigot pipe for capillary non-welded joints according to claim 7, characterized in that, ​

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