Pipe fitting machining method, sleeve preparation method of valve device and valve device
The pipe processing method of steel strip coil rolling and heat treatment solves the problem of uneven wall thickness of metal steel pipes in the vehicle thermal management system, improving product quality and production efficiency.
Patent Information
- Application Number
- CN202410309416.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-19
- Publication Date
- 2025-09-19
AI Technical Summary
In the on-board thermal management circulation system, the metal steel pipes prepared by the stretching process have problems such as uneven wall thickness, increased roughness and possible cracks, which affect product quality and mechanical stability.
The steel strip coiling process is adopted, and the pipe fittings are prepared through welding and pipe rolling processes. Combined with heat treatment and fixed-length cutting, the uniformity of wall thickness is ensured, and burrs are removed through grinding disc polishing, which simplifies the production process and improves the mechanical properties.
The pipe wall thickness is made uniform, the roughness is reduced, the product quality and mechanical properties are improved, the production process is simplified, and the manufacturing cost is reduced.
Smart Images
Figure CN120663070A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of pipe fitting preparation, and in particular to a pipe fitting processing method, a sleeve preparation method for a valve device, and a valve device. Background Art
[0002] In the vehicle-mounted thermal management circulation system, the throttle control valve can distribute the flow and pressure of the pipeline, and the water distribution pipeline connected to the throttle control valve is generally a short metal steel pipe. In the actual production and preparation process, in order to simplify the process steps and save costs, a stretching process can be used to complete the preparation in one go through a mold.
[0003] However, in actual applications, the stretching process requires the use of the material's flow, extension and deformation capabilities, especially for steel structures. During the production process, uneven wall thickness may occur, resulting in increased wall roughness and even cracks, affecting product quality and mechanical stability. Summary of the Invention
[0004] The present application aims to provide a pipe processing method, a sleeve preparation method for a valve device, and a valve device, which can improve the problem of uneven wall thickness in the pipe preparation process.
[0005] The present application provides a method for processing a pipe fitting, wherein the pipe fitting is rolled from a steel strip coil, and the wall thickness at the pipe fitting end is substantially consistent with the wall thickness at the pipe body, comprising the following steps:
[0006] Coiling the tube strip blank and welding it to form a blank tube;
[0007] The billet tube is subjected to at least a tube rolling process to obtain a pipe fitting of a target diameter;
[0008] Wherein, before entering the cold reducing mill to start the tube rolling process, the pipe processing method further includes heat treating the billet tube after coiling.
[0009] The tube strip with a basically flat surface is processed and then welded to form a billet tube with relatively uniform wall thickness. After preheating, the plasticity of the billet tube can be improved and the deformation resistance can be reduced. Then, the diameter of the billet tube is reduced by the tube rolling process. Rolling can refine the material grain through the recrystallization process, thereby achieving a more uniform material structure, so that the billet tube gradually reduces in diameter and wall thickness until the required finished product size is reached. At the same time, the mechanical properties of the material are improved and the roughness of the material is reduced during the tube making process.
[0010] The present application also provides a method for preparing a sleeve of a valve device, comprising the following steps:
[0011] S1: The steel strip is made into a billet tube through the welding process;
[0012] S2: The billet tube is subjected to at least one tube rolling process to obtain a pipe fitting with a target diameter.
[0013] S3: Cut the cross section of the pipe fitting along the vertical center line to a predetermined length to produce multiple short pipes of equal length;
[0014] S4: Then put the short pipes into the grinding disc in batches for magnetic polishing to remove burrs, so as to obtain the sleeve connected to the valve seat.
[0015] Through the processing technology of this application, pipe fittings are formed by welding steel strip coils and then undergo at least one reduction process of pipe rolling. Rolling can refine the material grains through the recrystallization process, making the structure more uniform and improving the uneven wall thickness problem during pipe manufacturing. By cutting the pipe fittings to a fixed length and polishing them in batches, the individual deburring process steps can be relatively simplified, improving the production efficiency of batch production, reducing the interference of the chamfering process at the end for deburring on the pipe fitting end wall thickness, and reducing the impact of the chamfering at the end on welding and pressure strength.
[0016] The present application further provides a valve device, which includes a valve seat and a sleeve, wherein the sleeve includes a first end and a second end, the first end is fixedly connected to the valve seat, and the second end is connected to an upper head, the upper head includes a guide portion extending into the interior of the sleeve, and the outer wall of the guide portion is interference fit with the inner wall of the sleeve.
[0017] Since the wall thickness of the pipe fitting is basically uniform, the upper head extends into the sleeve through the guide part, and the circumferential pressure-bearing force after the sleeve inner wall is fixed to the guide part by interference fit is also relatively stable, thereby improving the reliability of the overall assembly of the valve device. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 This is a flow chart of a valve sleeve processing method according to an embodiment of the present application;
[0019] Figure 2 This is a schematic diagram of the valve structure of an embodiment of the present application.
[0020] Reference numerals
[0021] 1-valve seat, 2-sleeve, 3-upper head;
[0022] 21-first end, 22-second end;
[0023] 31 - guide portion, 32 - main body portion, 33 - contact surface. Specific embodiments
[0024] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with the present application. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the present application, as detailed in the appended claims.
[0025] It should be understood that the words "first", "second" and similar terms used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one" or "an" do not indicate a quantitative limitation, but rather indicate the presence of at least one; "several" indicates a quantity of two or more, unless otherwise specified. Directional terms such as up, down, left, right, front, back, inside, outside, top, bottom, etc. mentioned or may be mentioned in the text are defined relative to the structure shown in the corresponding drawings. They are relative concepts and may therefore change accordingly depending on their different positions and different usage states. Therefore, these or other directional terms should not be interpreted as restrictive terms. Words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects.
[0026] The following is combined with Figure 1-2 , the valve device of the exemplary embodiment of the present application is described in detail. In the absence of conflict, the features of the following embodiments and implementations can complement or combine with each other.
[0027] The present application provides a method for processing a pipe fitting. The pipe fitting is formed by rolling a steel strip. The steel strip used to form the pipe fitting is a long strip tube with relatively uniform wall thickness. The wall thickness of the pipe fitting at the end is substantially consistent with the wall thickness of the pipe body. The pipe fitting processing method comprises at least the following steps:
[0028] S1: The steel strip is made into a billet tube through the welding process;
[0029] S2: The blank tube is subjected to at least a tube rolling process to obtain a tube fitting of a target diameter.
[0030] Wherein, before entering the cold reducing mill to start the tube rolling process, the pipe processing method further includes heat treating and straightening the billet tube after coiling.
[0031] Preferably, the steel strip is made into a billet tube by a pipe welding process, including: starting from the end of the steel strip, the left and right sides are symmetrically rolled toward the middle, the two sides are close to each other to form a butt joint, and the butt joint is welded by a welding process to form a billet tube.
[0032] In some embodiments, along the conveying direction of the steel strip, at least a pipe rolling station and a welding station are included. During the transportation process, the steel strip first passes through the pipe rolling station to start rolling, and after rolling, a semi-open pipe roll with a butt seam is formed; then it continues to be conveyed backward to the welding station. The welding station adopts automatic welding, and the welding point of the welding gun is located at the butt seam. The forming direction of the butt seam is consistent with the conveying direction of the steel strip. During the welding process, it can be conveyed with the steel strip to achieve continuous welding of the butt seam.
[0033] Preferably, in the process of rolling the steel strip, it also includes at least rolling the steel strip from the end through multi-stage rollers, and welding along the butt joint gap after the butt joint to obtain a blank tube, and the blank tube includes an inner weld seam and an outer weld seam.
[0034] In some embodiments, the steel strip is gradually bent by a multi-stage roller press, thereby gradually winding the steel strip into a coiled tube through multi-stage contraction. It is understood that the rollers at each stage are arranged to gradually narrow along the conveying direction of the steel strip, gradually bending the steel plate to improve the reliability of the steel strip forming and reduce the impact of stress, deformation and springback on the welding effect of the seam gap width.
[0035] Furthermore, the resulting welded billet tube must be flattened and then subjected to at least one tube rolling process to produce a long tube of the desired target diameter. Flattening can involve first rolling the weld position to round it, followed by finish rolling to adjust the tube wall thickness. It is also understood that the weld position can also be corrected directly by rolling.
[0036] In some embodiments, the welded billet tube includes an inner weld seam and an outer weld seam. Specifically, before rolling the billet tube, the billet tube is also leveled. By grinding and polishing the inner weld seam and the outer weld seam, the surface welding slag on the billet tube is removed, the flatness of the welding surface is improved, and the interference of the weld seam on the uniformity of the wall thickness after the tube is rolled is reduced.
[0037] Preferably, the tube rolling process includes a mandrel inserted into the inside of the blank tube and a forming die located outside the blank tube. The mandrel and the forming die synchronously clamp the inner and outer sides of the tube wall for rolling. The forming dies with different inner diameters are adjusted or selected, and a long tube with a target diameter is obtained through multiple rolling.
[0038] The pipe rolling process includes primary rolling and secondary rolling, and the pipe fittings of the target diameter are obtained through the primary rolling and secondary rolling in sequence. The first processing amount of the target diameter obtained by the primary rolling is D1, and the second processing amount of the target diameter obtained by the secondary rolling is D2. The second processing amount D2 is less than the first processing amount D1.
[0039] As can be understood, a raw steel strip with a width of 42.8 mm and a thickness of 0.7 mm is provided, and formed and welded through a pipe welding process to produce a billet pipe with a diameter of approximately 14 mm and a wall thickness of 0.7 mm. This billet pipe is then rolled through a pipe rolling process to obtain a long pipe with a target diameter of approximately 11 mm and a wall thickness of approximately 0.5 mm. The rolling process can be performed directly through a single finishing rolling step, or can be performed by first completing a first processing step (D1) to achieve the target pipe diameter, and then completing a second processing step (D2) to achieve the target pipe diameter through a secondary rolling step.
[0040] In some embodiments, the rolling process specifically includes three rolling processes, wherein the processing volume per rolling process is respectively D1 for the first rolling process, D2 for the second rolling process, and D3 for the third rolling process, wherein D1 < D2 < D3. It is understood that after the raw steel strip is coiled and welded, the billet tube has a diameter of approximately 14 mm and a wall thickness of 0.7 mm. The billet tube is deburred at the tube end and subjected to heat treatment before rolling. After the first rolling process, the diameter is reduced to approximately 12 mm and the wall thickness is 0.6 mm. After the second rolling process, the diameter is reduced to approximately 11.5 mm and the wall thickness is 0.53 mm. After the third rolling process, the diameter is reduced to approximately 11 mm and the wall thickness is 0.5 mm.
[0041] Furthermore, the tube rolling process also includes heat treatment and straightening of the tubes before each rolling process. Preferably, the rolled tubes are degreased before heat treatment and then sent to a high-temperature furnace for heat treatment. The heat treatment temperature parameters and tube transport parameters are adjusted accordingly to control the forming quality.
[0042] In some embodiments, the high-temperature furnace temperature is controlled between 900°C and 1050°C, with multiple temperature zones corresponding to the locations of different pipe sections. It is understood that the high-temperature furnace includes an inlet and an outlet, and from the outside of the outlet, at least Zone 1 (900°C), Zone 2 (980°C), Zone 3 (1020°C), and Zones 4-5-6 (1050°C) are included. Long pipes pass through multiple temperature zones from the inlet to the outlet. After heat treatment, the rough-rolled pipe is straightened and then subjected to finish rolling to obtain pipes of the target diameter.
[0043] In addition, the pipe rolling process also includes controlling the pipe to perform primary rolling and secondary rolling at different linear speeds, wherein the linear speed of the primary rolling during the heat treatment process is v1, and the linear speed of the secondary rolling during the heat treatment process is v2, and v1<v2.
[0044] During an operation, the gas flow rate of the high-temperature furnace can be controlled at 10-30m3 / h to ensure that the temperature of each temperature zone is maintained within the preset range. By adjusting the heat treatment line speed during rolling to 32-48HZ, the mechanical properties are achieved to meet the requirements of tensile strength Rm ≥ 550MPa, yield strength Rp0.2: 220-320Mpa, elongation A: ≥ 52%, and hardness: 170-210HV.
[0045] Preferably, the linear speed v1 during the first rolling heat treatment process is 36HZ, and the pipe fittings are straightened after the hardness is 170-190HV. The linear speed v2 during the second rolling heat treatment process is 45HZ, and the pipe fittings are straightened after the hardness is 190-210HV. After repeated internal and external rolling, the problem of material uniformity can be effectively solved, ensuring the uniformity of the wall thickness of the entire pipe fitting. The material grains are refined through the rolling combined with the heat treatment recrystallization process, making its structure more uniform, thereby improving the mechanical properties of the material and reducing the roughness of the material.
[0046] In one process operation, the pipe rolling process sequentially undergoes primary rolling, secondary rolling, and tertiary rolling to reduce the pipe diameter. The pipe fitting processing method further includes: straightening before each rolling to reduce the pipe diameter, and / or degreasing after each rolling to reduce the pipe diameter. Preferably, the pipe making process sequentially comprises: steel strip coiling, forming and welding, pipe end deburring, heat treatment, straightening, flaw detection, primary rolling, degreasing, heat treatment, straightening, secondary rolling, degreasing, heat treatment, straightening, tertiary rolling, degreasing, laser cutting, magnetic polishing, inspection and packaging.
[0047] Cutting the long tube to length also includes: cutting the middle section of the long tube using a laser cutting process, and then cutting the middle section into equal sections to produce multiple short tubes of equal length. In some embodiments, the ends of the long tube are first cut using a laser cutting process, and then the short tubes are cut to length. This ensures the consistency of the end cuts of the short tubes, facilitating the uniform placement of the short tubes on a grinding wheel, and then performing magnetic polishing to deburr the ends, thereby producing a pipe fitting for connection to the valve seat.
[0048] It can be understood that compared with the traditional drawing process, there is no need to cut off the tube mouth of each short tube separately, which can not only simplify the preparation process during mass production, but also effectively reduce material loss, improve product utilization and reduce manufacturing costs.
[0049] The pipe fittings prepared by the process of the present application can be used as the valve device of the electronic expansion valve, and the valve device includes a valve seat 1 and a sleeve 2 connected to the valve seat 1, and the sleeve 2 includes a first end 21 and a second end 22, wherein the first end 21 is fixedly connected to the valve seat 1, and the second end 22 is connected to the upper head 3.
[0050] The present application also provides a method for preparing a sleeve of a valve device, comprising the following steps:
[0051] S1: The steel strip is made into a billet tube through the welding process;
[0052] S2: The billet tube is subjected to at least one tube rolling process to obtain a pipe fitting with a target diameter.
[0053] S3: Cut the cross section of the pipe fitting along the vertical center line to a predetermined length to produce multiple short pipes of equal length;
[0054] S4: Then put the short pipes into the grinding disc in batches for magnetic polishing to remove burrs, so as to obtain the sleeve connected to the valve seat.
[0055] In some embodiments, a through hole connecting to the valve cavity is provided on the valve seat 1, and the inner diameter of the through hole is close to the outer diameter of the sleeve 2. By plugging and assembling the first end 21 of the sleeve 2 with the through hole, a welding ring is sleeved on the sleeve 2 and fixed by a furnace welding process. After part of the solder is melted, it will fill the assembly gap between the two to achieve a sealed connection.
[0056] The upper head 3 includes a guide portion 31 that extends into the sleeve 2 for interference fit and a main body portion 32 located outside the sleeve 2. The connection between the main body portion 32 and the guide portion 31 forms an abutment surface 33 that abuts against the port of the second end 22. The abutment surface 33 is sealed to the top wall of the second end 22 by laser welding.
[0057] In some embodiments, the sleeve 2 is formed by rolling and finishing a steel strip, which not only ensures uniform wall thickness throughout the entire tube, but also eliminates the need for separate deburring of the ends of the sleeve 2. This reduces the effect of deburring and chamfering on the wall thickness of the tube end, thereby improving the pressure-bearing performance of the sleeve 2. Furthermore, the guide portion 31 guides assembly, thereby reducing the difficulty of assembly alignment, reducing the upper head 3's reliance on the chamfer of the tube end for guidance, simplifying the production process of the sleeve 2, and improving the wall thickness uniformity and pressure-bearing strength of the sleeve 2.
[0058] It should be noted that the above embodiments are only used to illustrate the present invention and are not intended to limit the technical solutions described in the present invention. Although this specification has described the present invention in detail with reference to the above embodiments, it should be understood by those skilled in the art that the present invention can still be modified or replaced by equivalents, and all technical solutions and improvements thereof that do not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.
Claims
1. A pipe processing method, characterized in that: The pipe fitting processing method comprises the following steps: Coiling the tube strip blank and welding it to form a blank tube; The billet tube is subjected to at least a tube rolling process to obtain a pipe fitting of a target diameter; Wherein, before entering the cold reducing mill to start the tube rolling process, the pipe processing method further includes heat treating the billet tube after coiling.
2. The pipe processing method according to claim 1, characterized in that: The method of curling the tube strip blank and welding it into a blank tube comprises: The steel strip is rolled from the end by multi-stage rollers, and after butting, the steel strip is welded along the butt joint gap to produce a billet tube. The billet tube includes an inner weld seam and an outer weld seam. The tube rolling process includes rolling and leveling the inner weld seam and the outer weld seam inside and outside.
3. The pipe processing method according to claim 1, characterized in that: The tube rolling process includes at least one rolling and two rollings. The heat treatment feeding line speed before the one rolling is v1, and the heat treatment feeding line speed before the two rolling is v2, wherein v1<v2.
4. The pipe processing method according to any one of claims 1 to 3, characterized in that: The pipe rolling process sequentially produces a pipe fitting of a target diameter through a primary rolling process and a secondary rolling process. The first processing amount of the target pipe diameter produced by the primary rolling process is D1, and the second processing amount of the target pipe diameter produced by the secondary rolling process is D2. The second processing amount D2 is less than the first processing amount D1.
5. The pipe processing method according to claim 4, characterized in that: The pipe rolling process further includes three rolling steps, wherein the third processing amount of the pipe diameter reducing rolling by the three rolling steps is D3, and the third processing amount D3 is less than the second processing amount D2. After the pipe rolling process is completed, the pipe fitting with the target diameter is obtained.
6. The pipe processing method according to any one of claims 1 to 5, characterized in that: The pipe rolling process sequentially reduces the pipe diameter through primary rolling, secondary rolling and tertiary rolling during the rolling process. The pipe processing method further includes: performing a straightening treatment before each rolling to reduce the pipe diameter, and / or performing a degreasing treatment after each rolling to reduce the pipe diameter.
7. A method for preparing a sleeve of a valve device, characterized in that: The pipe fitting processing process according to any one of claims 1 to 6, wherein the sleeve preparation method comprises: Coiling the tube strip blank and welding it to form a blank tube; The billet tube is subjected to at least a tube rolling process to obtain a pipe fitting of a target diameter; Cutting the cross section of the pipe along the vertical center line to a predetermined length to obtain a plurality of short pipes of equal length; Then, the short pipes are put into the grinding disc in batches for magnetic polishing to remove burrs, thereby obtaining a sleeve connected to the valve seat.
8. The method for preparing a sleeve according to claim 7, wherein: The cutting of the pipe to a predetermined length further includes: cutting a middle section of the pipe by a laser cutting process, and cutting the middle section into equal parts and predetermined lengths.
9. A valve device, characterized in that: The valve device includes a valve seat and a sleeve, and the sleeve is prepared by the preparation method described in any one of claims 1 to 8. The pipe fitting includes a first end and a second end, the first end is fixedly connected to the valve seat, and the second end is connected to an upper head, and the upper head includes a guide portion extending into the interior of the pipe fitting, and the outer wall of the guide portion is interference fit with the inner wall of the pipe fitting.
10. The valve device according to claim 9, characterized in that The upper head also includes a main body portion located outside the pipe fitting, the main body portion extends radially outward relative to the guide portion to form an abutment surface, and the abutment surface is sealed and connected to the second end top wall by laser welding.