A copper tube diameter reducing machining mechanism and machining method

Abstract

This invention relates to the field of copper tube processing technology, and more particularly to a copper tube diameter reduction processing mechanism and method, comprising an inner support unit located inside the copper tube and an outer support mold located outside the copper tube; the inner support unit includes a guide tube, two sealing rings mounted opposite each other on the guide tube, and a guide hole formed on the guide tube between the two sealing rings. This invention effectively solves the problem of copper tube tearing damage caused by uneven stress during traditional diameter reduction processing. By utilizing the contact between fluid and the inner wall of the copper tube to provide uniform pressure, stress concentration can be effectively avoided, resulting in more uniform deformation at different locations on the copper tube, improving the structural integrity and reliability of the finished product, while reducing friction damage to the copper tube and improving its flatness. This frictionless processing method can effectively extend the service life of equipment and facilitate batch processing of copper tubes.

Description

Technical Field

[0001] This invention relates to the field of copper tube processing technology, and in particular to a copper tube diameter changing processing mechanism and processing method. Background Technology

[0002] In many industrial fields such as refrigeration, air conditioning, heat exchangers and fluid transportation, copper tubes are widely used in the connection and construction of various pipeline systems due to their excellent thermal conductivity, corrosion resistance and good processing performance. In the manufacturing and assembly process of these systems, it is often necessary to process the ends of copper tubes by changing their diameter, that is, to change their port diameter through the hole expansion process in order to meet the requirements of socket, welding or sealing connection between different pipe diameters.

[0003] Currently, the conventional technique for expanding the diameter of copper tube ends mainly employs the direct extrusion method using rigid mandrels. This process involves directly pressing a rigid mandrel, pre-machined to a specified diameter, into the end of the copper tube to be processed under axial force. Utilizing the physical property that the outer diameter of the mandrel is larger than the inner diameter of the copper tube, the copper tube wall is forced to undergo plastic deformation, thereby achieving diameter expansion. However, due to the uneven axial distribution of the radial pressure applied to the inner wall of the copper tube by the mandrel during the extrusion process, especially in the initial flaring section and deformation concentration area, the circumferential tensile stress on the material often exceeds its plastic limit. This can easily lead to uneven thinning of the copper tube wall, or even cracks or tearing defects. At the same time, a large area of ​​sliding friction is formed between the mandrel and the inner wall of the copper tube, which can easily aggravate the wear of the inner wall of the copper tube and the mandrel. Moreover, the friction makes the processing process unstable, making it difficult to guarantee the dimensional accuracy and processing quality of products during batch processing. Summary of the Invention

[0004] This invention provides a copper tube diameter changing processing mechanism and processing method, which can effectively solve the problems in the background art.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A copper tube diameter changing processing mechanism includes an inner support unit located inside the copper tube and an outer support mold located outside the copper tube; The inner support unit includes a guide pipe, two sealing rings installed opposite to each other on the guide pipe, and a guide hole opened on the guide pipe and located between the two sealing rings. The two sealing rings separate the internal space of the copper tube. The guide pipe supplies high-pressure fluid to the space between the two sealing rings through the guide hole. The high-pressure fluid is used to expand the diameter of the copper tube externally. The outer support mold is composed of several sub-molds spliced ​​together, and the outer support mold is used to define the shape of the copper tube. Each of the sub-molds has an arc-shaped edge at both ends. Several arc-shaped edges on the same side of the outer support mold form a sizing ring and are fitted onto the outer wall of the copper tube. The sizing ring is used in conjunction with the corresponding sealing ring.

[0006] Furthermore, a negative pressure pipe is connected to the outer support mold, which is used to draw the pressure around the outer wall of the copper tube inside the outer support mold into a negative pressure.

[0007] Furthermore, the guide tube includes a vertically arranged supply tube, a fixed cylinder, a movable cylinder, and a support column. The supply tube is connected to the fixed cylinder, the fixed cylinder and the movable cylinder are coaxially arranged and slide relative to each other, the movable cylinder is connected to the support column, and the two sealing rings are respectively disposed on the supply tube and the support column. The guide hole is a notch arranged along the axis of the movable cylinder. The number of the notches is set to two and they are distributed opposite each other on both sides of the axis of the movable cylinder. The notch extends from one end of the movable cylinder to the middle of the movable cylinder. The end of the movable cylinder is provided with a semi-sealing plate that cooperates with the two notches. A sealing plate is slidably arranged inside the movable cylinder. A partition is provided inside the fixed cylinder along the axis of the fixed cylinder. The partition divides the internal space of the fixed cylinder into an active space and a flow guiding space. The flow guiding space is connected to the supply pipe. The sealing plate is fixed relative to the partition. The end of the active cylinder is slidably inserted into the fixed cylinder, and the partition is slidably inserted into the two notches. The semi-sealing plate is located in the active space.

[0008] Furthermore, a spring connecting the semi-sealing plate and the fixed cylinder is provided within the movable space, and two limiting rings are provided inside the movable cylinder to limit the range of motion of the sealing plate.

[0009] Furthermore, a baffle is provided inside the supply pipe, and the baffle and the inner wall of the supply pipe form an air guiding space. The air guiding space is connected to the active space through an air hole one, and an air hole two is opened on the outer wall of the supply pipe to communicate with the air guiding space. The support column is provided with an air passage that communicates with the movable cylinder.

[0010] Furthermore, the arc-shaped edge at one end of the mold parting is composed of a guide edge and a movable edge that can slide inside the guide edge. The movable edge is connected to the mold parting via a spring, and the movable edge cooperates with the sealing ring on the support column.

[0011] Furthermore, the position of the sealing ring on the supply pipe along the axial direction of the supply pipe can be adjusted.

[0012] Furthermore, the sealing ring includes two ring bodies and a rubber sleeve located between the two ring bodies and forming a sealed space with the two ring bodies. The two ring bodies seal the copper tube through the rubber sleeve. One ring body is fixed relative to the corresponding supply pipe or support column, and the other ring body is slidably disposed on the corresponding supply pipe or support column. The other ring body is used for fluid contact between the two sealing rings.

[0013] Furthermore, the inner wall and outer wall of the rubber sleeve are respectively configured as an inner concave surface and an outer concave surface, and both ends of the rubber sleeve are configured as slopes facing the outer side of the rubber sleeve.

[0014] A method for processing copper tubes with reduced diameter includes the following steps: Adjust the position of the two sealing rings on the guide tube so that the distance between the two sealing rings meets the requirements of the copper tube diameter change length; Insert the guide tube and its two sealing rings into the copper tube. The copper tube between the two sealing rings is the variable diameter area. Assemble several sub-molds on the outer support mold on the outer wall of the copper tube so that the two sizing rings on the outer support mold correspond to the two sealing rings. High-pressure fluid is introduced between the two sealing rings through the supply pipe and the guide hole, and the high-pressure fluid externally expands and changes the diameter of the copper pipe. The gas inside the outer support mold is extracted by using a negative pressure pipe, so that a negative pressure is formed around the outer wall of the copper tube diameter change area. The deformation of the copper tube is controlled by the positive and negative pressure difference between the inside and outside of the copper tube. When the outer wall of the copper tube deforms and comes into contact with the inner wall of the outer support mold, the diameter change of the copper tube is completed; Remove the outer support mold and inner support unit, cut the copper tube at the specified position in the diameter change area, and the copper tube processing is completed.

[0015] The technical solution of this invention can achieve the following technical effects: This method effectively solves the problem of copper tube tearing damage caused by uneven stress during traditional diameter reduction machining. By utilizing the contact between the fluid and the inner wall of the copper tube to provide uniform pressure, stress concentration can be effectively avoided, resulting in more uniform deformation at different locations on the copper tube. This improves the structural integrity and reliability of the finished product, while reducing friction damage and improving the flatness of the copper tube. This frictionless machining method can effectively extend the service life of the equipment and facilitate batch processing of copper tubes. The external support mold restricts the shape of the copper tube, effectively improving the machining accuracy and allowing different locations on the copper tube to withstand internal and external extrusion simultaneously, thus improving the uniformity of deformation. The combined use of two sizing rings and two sealing rings limits the deformation range of the copper tube, preventing gaps between the inner wall of the copper tube and the sealing rings caused by internal pressure, which could lead to fluid leakage and pressure failure.

[0016] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, specific embodiments of this application are given below. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a copper tube diameter changing processing mechanism. Figure 2 This is a cross-sectional view of the external support mold. Figure 3 for Figure 2 A schematic diagram of the structure when the guide edge and the moving edge are combined; Figure 4 This is a structural schematic diagram of the internal support unit; Figure 5 for Figure 4 Schematic diagram of the central guide tube; Figure 6 for Figure 5 A schematic diagram of the cross-sectional structure; Figure 7 for Figure 5 A schematic diagram of the exploded structure; Figure 8 for Figure 7 A cross-sectional view of the movable cylinder. Figure 9 for Figure 7 A cross-sectional view of the fixed cylinder. Figure 10 for Figure 4 Schematic diagram of the middle sealing ring; Figure 11 for Figure 10 A schematic diagram of the exploded structure; Figure 12 for Figure 11 A magnified view of the structure at point A in the middle; Attached reference numerals: 100, copper pipe; 200. Internal support unit; 201. Guide tube; 202. Air passage; 203. Guide hole; 204. Supply pipe; 205. Fixed cylinder; 206. Movable cylinder; 207. Support column; 208. Semi-sealing plate; 209. Partition plate; 210. Sealing plate; 211. Spring 1; 212. Limiting ring; 213. Baffle plate; 214. Air hole 1; 215. Air hole 2; 300. External support mold; 301. Mold parting; 302. Arc edge; 303. Negative pressure pipe; 304. Guide edge; 305. Movable edge; 306. Spring II; 400. Sealing ring; 401. Ring body; 402. Rubber sleeve; 403. Inner concave surface; 404. Outer concave surface; 405. Slope; 406. Guide channel; 407. Conical air inlet; 408. Air groove; 409. Conical disc; 410. Spring three. Detailed Implementation

[0019] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] like Figures 1 to 4 As shown, this application provides a copper tube diameter changing processing mechanism, including an inner support unit 200 located inside the copper tube 100 and an outer support mold 300 located outside the copper tube 100. The inner support unit 200 includes a flow guide pipe 201, two sealing rings 400 mounted opposite to each other on the flow guide pipe 201, and a flow guide hole 203 opened on the flow guide pipe 201 and located between the two sealing rings 400. The two sealing rings 400 divide the internal space of the copper tube 100. The flow guide pipe 201 supplies high-pressure fluid to the space between the two sealing rings 400 through the flow guide hole 203. The high-pressure fluid is used to expand the diameter of the copper tube 100. The outer support mold 300 is composed of several parting molds 301 spliced ​​together, and the outer support mold 300 is used to define the shape of the copper tube 100. Each parting mold 301 has an arc edge 302 at both ends. Several arc edges 302 on the same side of the outer support mold 300 form a sizing ring and are fitted onto the outer wall of the copper tube 100. The sizing ring is used in conjunction with the corresponding sealing ring 400.

[0022] Specifically, the inner support unit 200 and the outer support mold 300 are at the same height on the copper tube 100. The inner support unit 200 performs external support and diameter reduction processing on the copper tube 100 from the inside, and the outer support mold 300 limits the final size of the deformation of the outer wall of the copper tube 100 from the outside, so that the shape of the diameter reduction area of ​​the copper tube 100 is uniform. The sizing ring on the outer support mold 300 can cooperate with the sealing ring 400 on the inner support unit 200 to compress and limit the outer and inner walls of the copper tube 100, so that this area of ​​the copper tube 100 does not deform, thereby limiting the diameter reduction range of the copper tube 100. This prevents the deformation area of ​​the copper tube 100 from exceeding the sealing ring 400 and causing leakage of the fluid inside the copper tube 100 when the copper tube 100 changes diameter, and facilitates the confinement of the fluid within the deformation area of ​​the copper tube 100.

[0023] The two sealing rings 400 in the inner support unit 200 are distributed opposite each other along the axis of the guide tube 201. One sealing ring 400 is located at the end of the guide tube 201, and the other sealing ring 400 is located in the middle of the guide tube 201. In this way, when the two sealing rings 400 are inserted into the copper tube 100, the two sealing rings 400 can contact the inner wall of the copper tube 100 and separate the area between the two sealing rings 400. This area is the diameter-changing processing area of ​​the copper tube 100. At the same time, the two sealing rings 400 can be used to limit the fluid and prevent the fluid supplied between the two sealing rings 400 from leaking. The pressure of the high-pressure fluid on the inner wall of the copper tube 100 can make the force on different positions in the diameter-changing area of ​​the copper tube 100 uniform, and prevent the copper tube 100 from tearing.

[0024] In use, a portion of the guide tube 201 and two sealing rings 400 are inserted into the copper tube 100. The two sealing rings 400 divide the internal space of the copper tube 100. One sealing ring 400 is located near the end of the copper tube 100, and the other is located deep within the copper tube 100. Several parting molds 301 are assembled on the outer wall of the copper tube 100. The positions of the two sizing rings correspond to the positions of the two sealing rings 400, meaning the sizing rings and sealing rings 400 are at the same height on the copper tube 100. This facilitates the compression and confinement of the inner and outer walls of the copper tube 100 using the sizing rings and sealing rings 400, thereby improving sealing and preventing leakage at this location. The copper tube 100 is deformed; high-pressure fluid is introduced between the two sealing rings 400 through the guide tube 201 and the guide hole 203. The high-pressure fluid can contact the inner wall of the copper tube 100 and expand the copper tube 100, thereby gradually changing the diameter of the copper tube 100. When the outer wall of the copper tube 100 contacts the inner wall of the outer support mold 300, the diameter of the diameter-changing area of ​​the copper tube 100 reaches the specified requirements. The inner support unit 200 and the outer support mold 300 are removed. Since the end of the copper tube 100 has a small area that has not changed diameter, it is cut at the specified position of the diameter-changing area of ​​the copper tube 100 to obtain a copper tube 100 with a larger diameter at the end. At this time, the diameter-changing processing of the copper tube 100 is completed.

[0025] It should be noted that the subsequent cutting of the copper tube 100 can be accomplished using external cutting blades, laser cutting machines, or other equipment. When high-pressure fluid is introduced between the two sealing rings 400, since there is gas between the two sealing rings 400, a separate gas path can be set up in the guide pipe 201 to expel this gas or retain it between the two sealing rings 400. Since the diameter reduction processing of the copper tube 100 mainly utilizes high-pressure external support from the inside out, air pressure can also achieve the same effect without affecting the normal use of the structure. The high-pressure fluid can be hydraulic oil, nitrogen, etc.

[0026] The technical solution of this invention effectively solves the problem of tearing damage to the copper tube 100 caused by uneven stress during traditional diameter reduction processing. By utilizing the contact between the fluid and the inner wall of the copper tube 100 to provide uniform pressure, stress concentration can be effectively avoided, making the deformation of different positions on the copper tube 100 more uniform, improving the structural integrity and reliability of the finished product, while reducing friction damage to the copper tube 100 and improving its flatness. This frictionless processing method can effectively extend the service life of the equipment and facilitate the batch processing of copper tubes 100. By using the external support mold 300 to limit the shape of the copper tube 100, the processing accuracy of the copper tube 100 can be effectively improved, allowing different positions on the copper tube 100 to withstand internal and external extrusion simultaneously, improving the uniformity of deformation of the copper tube 100. By using the cooperation of two sizing rings and two sealing rings 400, the deformation range of the copper tube 100 can be limited, avoiding the formation of gaps between the inner wall of the copper tube 100 and the sealing rings 400 due to internal pressure, which could lead to fluid leakage and pressure failure.

[0027] Furthermore, such as Figure 2 As shown, a negative pressure pipe 303 is connected to the outer support mold 300. The negative pressure pipe 303 is used to draw the pressure around the outer wall of the copper pipe 100 inside the outer support mold 300 into a negative pressure.

[0028] The negative pressure pipe 303 is connected to an external air pump. When the copper tube 100 is being processed to reduce its diameter, the air inside the outer support mold 300 is extracted through the negative pressure pipe 303, creating a negative pressure near the outer wall of the copper tube 100. This increases the pressure difference between the inside and outside of the copper tube 100, increases the deformation speed of the copper tube 100, and facilitates the equalization of pressure at different positions on the inside and outside of the copper tube 100, thereby improving the processing quality of the copper tube 100. Moreover, this method can relatively reduce the pressure value of the fluid inside the copper tube 100, thereby reducing processing requirements and difficulty.

[0029] In some embodiments, hydraulic oil or other fluids can also be stored inside the outer support mold 300. By using the negative pressure pipe 303 to extract the fluid, a negative pressure state is formed on the outer wall of the copper tube 100. Due to the incompressibility of fluids such as hydraulic oil, the impact of gas volume changes on the diameter change processing of the copper tube 100 when using gas can be reduced.

[0030] Furthermore, such as Figures 5 to 9 As shown, the guide pipe 201 includes a vertically arranged supply pipe 204, a fixed cylinder 205, a movable cylinder 206, and a support column 207. The supply pipe 204 is connected to the fixed cylinder 205. The fixed cylinder 205 and the movable cylinder 206 are coaxially arranged and slide relative to each other. The movable cylinder 206 is connected to the support column 207. Two sealing rings 400 are respectively arranged on the supply pipe 204 and the support column 207. The guide hole 203 is a notch arranged along the axis of the movable cylinder 206. The number of notches is set to two and they are relatively distributed on both sides of the axis of the movable cylinder 206. The notch extends from one end of the movable cylinder 206 to the middle of the movable cylinder 206. The end of the movable cylinder 206 is provided with a semi-sealing plate 208 that cooperates with the two notches. A sealing plate 210 is slidably arranged inside the movable cylinder 206. A partition 209 is provided inside the fixed cylinder 205 along the axis of the fixed cylinder 205. The partition 209 divides the internal space of the fixed cylinder 205 into an active space and a flow guiding space. The flow guiding space is connected to the supply pipe 204. The sealing plate 210 is fixed relative to the partition 209. The end of the active cylinder 206 is slidably inserted into the fixed cylinder 205, and the partition 209 is slidably inserted into the two notches. The semi-sealing plate 208 is located in the active space.

[0031] The supply pipe 204, fixed cylinder 205, movable cylinder 206, and support column 207 are arranged from bottom to top and are coaxially positioned. Fluid flows upward from the supply pipe 204. The supply pipe 204 and fixed cylinder 205 are a single unit, and the movable cylinder 206 and support column 207 are a single unit. The movable cylinder 206 can slide relative to the fixed cylinder 205, thereby allowing the two units to move relative to each other. Since two sealing rings 400 are respectively provided on the supply pipe 204 and support column 207, the relative movement of the two units helps the copper pipe 100 to move between the two sealing rings 400 during diameter reduction processing. The reduced length of the copper tube 100 facilitates the addition of some material to its increased outer diameter, preventing the copper tube 100 from having a reduced wall thickness due to diameter changes when its length remains constant, which would affect its strength and service life. The supply tube 204 can be used as a fixed end, allowing the movable cylinder 206 and the support column 207 to move relative to the supply tube 204, thereby allowing the sealing ring 400 located deep within the copper tube 100 to move. Alternatively, the movable cylinder 206 and the support column 207 can be used as fixed ends, allowing the supply tube 204 to move relative to each other, in which case the sealing ring 400 at the end of the copper tube 100 can move.

[0032] like Figure 5As shown, the guide hole 203 is a notch extending upward from the bottom of the movable cylinder 206. Part of this notch can be used to introduce high-pressure fluid between the two sealing rings 400, and the other part is used to cooperate with the partition 209. That is, when the bottom of the movable cylinder 206 is slidably inserted into the fixed cylinder 205, the partition 209 is inserted into the two notches in the opposite direction, thereby dividing part of the space inside the movable cylinder 206. The side of the bottom of the movable cylinder 206 with the semi-sealing plate 208 is located in the movable space, and the other side of the bottom of the movable cylinder 206 is located in the guide space. The space above the semi-sealing plate 208 can be connected to the guide space through the space between the sealing plate 210 and the partition 209. The sealing plate 210 and the partition 209 are connected by a connecting rod, that is, the space between the sealing plate 210 and the partition 209 is the space on both sides of the connecting rod.

[0033] In use, external high-pressure fluid can be introduced into the guide space through the supply pipe 204. The fluid in the guide space can enter the right side of the movable cylinder 206 and flow to the semi-sealing plate 208 through the space between the partition plate 209 and the sealing plate 210. At this time, the fluid exerts downward pressure on the semi-sealing plate 208, and the semi-sealing plate 208 moves down and drives the movable cylinder 206, the support column 207 and the sealing ring 400 on it to move synchronously. This changes the length of the copper pipe 100 between the two sealing rings 400. When the movable cylinder 206 moves, it will generate relative movement with the sealing plate 210. The sealing plate 210 is mainly set to make the fluid exert downward force on the semi-sealing plate 208 without exerting upward force on the movable cylinder 206 or the support column 207, thereby allowing the movable cylinder 206 to generate movement opposite to the fluid flow direction under the action of the fluid. Some of the fluid in the movable cylinder 206 can enter between the two sealing rings 400 through the notch, thereby providing power for the deformation of the copper pipe 100.

[0034] In the vertical direction or along the direction of movement of the movable cylinder 206, the area of ​​the fluid acting on the semi-sealing plate 208 needs to be greater than the area of ​​the fluid acting on the movable cylinder 206 and the upper sealing ring 400, so that the entire movable cylinder 206 is subjected to downward force.

[0035] Furthermore, such as Figure 6 and Figure 8 As shown, a spring 211 is provided in the movable space to connect the semi-sealing plate 208 and the fixed cylinder 205, and two limiting rings 212 are provided in the movable cylinder 206 to limit the range of motion of the sealing plate 210.

[0036] When the movable cylinder 206 and the semi-sealing plate 208 are subjected to fluid and move, the spring 211 undergoes elastic deformation. When the fluid pressure decreases, the spring 211 can push the movable cylinder 206 and the semi-sealing plate 208 back to their original positions. The two limiting rings 212 can limit the movement area of ​​the sealing plate 210 within the movable cylinder 206, thereby limiting the relative movement range of the two sealing rings 400.

[0037] Furthermore, such as Figure 9 As shown, a baffle 213 is provided inside the supply pipe 204. The baffle 213 and the inner wall of the supply pipe 204 form an air guiding space. The air guiding space is connected to the activity space through an air hole 214. An air hole 215 connected to the air guiding space is provided on the outer wall of the supply pipe 204. The support column 207 is provided with an air passage 202 that communicates with the movable cylinder 206.

[0038] When the semi-sealing plate 208 is subjected to fluid and moves, the moving space decreases. At this time, the gas in the moving space can be discharged through the first air hole 214, the air guiding space and the second air hole 215. This structure is used to keep the internal pressure of the moving space constant, so as to avoid the air pressure change caused by the change of space size and affect the normal movement of the moving cylinder 206.

[0039] Furthermore, the arc-shaped edge 302 at one end of the mold parting 301 is composed of a guide edge 304 and a movable edge 305 that can slide inside the guide edge 304. The movable edge 305 is connected to the mold parting 301 by a spring 306, and the movable edge 305 is used in conjunction with the sealing ring 400 on the support column 207.

[0040] Since the distance between the two sealing rings 400 changes when the copper tube 100 changes diameter, the distance between the two sizing rings needs to change synchronously; otherwise, the friction between the sizing rings and the outer wall of the copper tube 100 will affect the normal movement of the two sealing rings 400.

[0041] like Figure 2 and Figure 3 As shown, the sizing ring formed by several arc-shaped edges 302 on the lower side cooperates with the lower sealing ring 400 and is in a fixed state, while the sizing ring formed by several arc-shaped edges 302 on the upper side is allowed to move. Specifically, the spring 306 pushes the movable edge 305 so that the movable edge 305 is initially higher than the parting mold 301. At this time, the movable edge 305 corresponds to the upper sealing ring 400. When the upper sealing ring 400 moves downward, the length of the copper tube 100 between the two sealing rings 400 decreases. At this time, the copper tube 100 can use friction to drive the movable edge 305 to slide on the guide edge 304, so that the movable edge 305 is completely combined with the inner wall of the parting mold 301. At this time, the spring 306 undergoes elastic deformation.

[0042] To limit the position of the movable edge 305, an outer edge can be provided at the top of the movable edge 305. When the outer edge contacts the top of the guide edge 304, the movable edge 305 will no longer move.

[0043] Furthermore, the position of the sealing ring 400 on the supply pipe 204 along the axial direction of the supply pipe 204 can be adjusted.

[0044] When different diameter lengths need to be processed, the distance between the two sealing rings 400 can be adjusted in the initial state. That is, the initial positioning of the two sealing rings 400 can be achieved by adjusting the position of the sealing rings 400 on the supply pipe 204. Specifically, the sealing rings 400 can be fixed to the supply pipe 204 by sealing rings, pressure strips, and bolts. When adjusting the position of the sealing rings 400, simply loosen the bolts and move the sealing rings 400.

[0045] Furthermore, such as Figures 10 to 11 As shown, the sealing ring 400 includes two ring bodies 401 and a rubber sleeve 402 located between the two ring bodies 401 and forming a sealed space with the two ring bodies 401. The two ring bodies 401 seal the copper tube 100 through the rubber sleeve 402. One ring body 401 is fixed relative to the corresponding supply pipe 204 or support column 207, and the other ring body 401 is slidably disposed on the corresponding supply pipe 204 or support column 207. The ring body 401 is used for fluid contact between the two sealing rings 400.

[0046] Since the movable ring 401 needs to be in contact with the fluid, the two movable rings 401 of the two sealing rings 400 are located on the inner side, and the two fixed rings 401 are located on the outer side. The two ends of the rubber sleeve 402 are respectively installed on the outer circumference of the two rings 401. When the high-pressure fluid between the two sealing rings 400 exerts a squeezing force on the inner ring 401, the two rings 401 approach each other, and their internal space is compressed. The air pressure generated during the compression of the space pushes the rubber sleeve 402 to adhere tightly to the inner wall of the copper tube 100. At the same time, the shortening of the distance between the two rings 401 can squeeze the rubber sleeve 402 outward, thereby further improving the adhesion between the rubber sleeve 402 and the inner wall of the copper tube 100 and improving the sealing performance between the sealing rings 400 and the copper tube 100.

[0047] Furthermore, such as Figure 11 As shown, the inner wall and outer wall of the rubber sleeve 402 are respectively configured as an inner concave surface 403 and an outer concave surface 404, and both ends of the rubber sleeve 402 are configured as slopes 405 facing the outside of the rubber sleeve 402.

[0048] The concave surface 403 makes it easier to bend the rubber sleeve 402 when the two rings 401 approach each other, facilitating the outward compression of the rubber sleeve 402 and making it easier to bend. The concave surface 404 increases the interface area between the rubber sleeve 402 and the inner wall of the copper tube 100 when the rubber sleeve 402 is compressed and bent, thereby improving the sealing performance. The slope 405 can utilize the pressure of the fluid to make the edge of the rubber sleeve 402 fit more tightly with the inner wall of the copper tube 100, improving the sealing performance.

[0049] like Figure 11 and Figure 12As shown, a guide channel 406 is provided on the outer ring 401 of the sealing ring 400, and a conical air port 407 is provided at the end of the guide channel 406 facing the outer side of the sealing ring 400. Several air grooves 408 are provided on the inner wall of the guide channel 406. A conical disc 409 is slidably disposed in the guide channel 406. The conical disc 409 cooperates with the conical air port 407. At the same time, the conical disc 409 is connected to the inner ring 401 by a spring 410. In its natural state... When the conical disc 409 separates from the conical air port 407, the space between the two rings 401 can be connected to the outside through the air groove 408. When one ring 401 is squeezed by the fluid and moves, the spring 410 and the conical disc 409 move synchronously. The conical disc 409 and the conical air port 407 come into contact and block the guide channel 406. At this time, the space between the two rings 401 is isolated from the outside. The gas between the two rings 401 is squeezed and the pressure is transmitted to the rubber sleeve 402.

[0050] Using the above structure, the space between the two rings 401 can be kept closed during operation and can be connected to the outside when idle, thereby avoiding the need to seal the gas in a sealed chamber and preventing the sealed chamber from leaking and affecting the normal use of the equipment.

[0051] A method for processing copper tubes with reduced diameter includes the following steps: Adjust the position of the two sealing rings 400 on the guide tube 201 so that the distance between the two sealing rings 400 meets the requirements of the variable diameter length of the copper tube 100; Insert the guide tube 201 and its two sealing rings 400 into the copper tube 100. The copper tube 100 between the two sealing rings 400 is a variable diameter area. Several parting molds 301 on the outer support mold 300 are assembled on the outer wall of the copper tube 100 so that the two sizing rings on the outer support mold 300 correspond to the positions of the two sealing rings 400. High-pressure fluid is introduced between the two sealing rings 400 through the supply pipe 204 and the guide hole 203, and the high-pressure fluid externally expands and changes the diameter of the copper pipe 100. The gas inside the outer support mold 300 is extracted by the negative pressure pipe 303, so that a negative pressure is formed around the outer wall of the diameter change area of ​​the copper tube 100. The deformation of the copper tube 100 is controlled by the positive and negative pressure difference between the inner and outer sides of the copper tube 100. When the outer wall of the copper tube 100 deforms and comes into contact with the inner wall of the outer support mold 300, the diameter change of the copper tube 100 is completed. Remove the outer support mold 300 and the inner support unit 200, cut the copper pipe 100 at the specified position in the diameter change area, and the copper pipe 100 processing is completed.

[0052] This method uses high-pressure fluid as the internal support medium to ensure uniform stress on the inner wall of the copper tube 100, fundamentally avoiding the local stress concentration and tearing problems that are easily caused by traditional rigid core extrusion. At the same time, it eliminates sliding friction and ensures the quality of the inner wall. By drawing negative pressure on the outside to form an internal and external pressure difference, it can both improve the forming efficiency in conjunction with the internal pressure and reduce the demand for internal pressure, making the process easier to control. Finally, the outer diameter is precisely defined by the outer support mold 300, ensuring the dimensional accuracy and shape consistency of the variable diameter area. This method has stable process, high yield, and regular end after processing, which is convenient for subsequent assembly and connection.

[0053] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of the application as defined herein, and are to be considered as covering any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from its scope. Thus, if such modifications and modifications fall within the scope of this application and its equivalents, this application intends to include such modifications and modifications.

Claims

1. A copper tube diameter changing processing mechanism, characterized in that, It includes an inner support unit located inside the copper tube and an outer support mold located outside the copper tube; The inner support unit includes a guide pipe, two sealing rings installed opposite to each other on the guide pipe, and a guide hole opened on the guide pipe and located between the two sealing rings. The two sealing rings separate the internal space of the copper tube. The guide pipe supplies high-pressure fluid to the space between the two sealing rings through the guide hole. The high-pressure fluid is used to expand the diameter of the copper tube externally. The outer support mold is composed of several sub-molds spliced ​​together, and the outer support mold is used to define the shape of the copper tube. Each of the sub-molds has an arc-shaped edge at both ends. Several arc-shaped edges on the same side of the outer support mold form a sizing ring and are fitted onto the outer wall of the copper tube. The sizing ring is used in conjunction with the corresponding sealing ring.

2. The copper tube diameter changing processing mechanism according to claim 1, characterized in that, A negative pressure pipe is connected to the outer support mold, which is used to draw the pressure around the outer wall of the copper tube inside the outer support mold into a negative pressure.

3. The copper tube diameter changing processing mechanism according to claim 1, characterized in that, The guide tube includes a vertically arranged supply tube, a fixed cylinder, a movable cylinder, and a support column. The supply tube is connected to the fixed cylinder, the fixed cylinder and the movable cylinder are coaxially arranged and slide relative to each other, the movable cylinder is connected to the support column, and the two sealing rings are respectively arranged on the supply tube and the support column. The guide hole is a notch arranged along the axis of the movable cylinder. The number of the notches is set to two and they are distributed opposite each other on both sides of the axis of the movable cylinder. The notch extends from one end of the movable cylinder to the middle of the movable cylinder. The end of the movable cylinder is provided with a semi-sealing plate that cooperates with the two notches. A sealing plate is slidably arranged inside the movable cylinder. A partition is provided inside the fixed cylinder along the axis of the fixed cylinder. The partition divides the internal space of the fixed cylinder into an active space and a flow guiding space. The flow guiding space is connected to the supply pipe. The sealing plate is fixed relative to the partition. The end of the active cylinder is slidably inserted into the fixed cylinder, and the partition is slidably inserted into the two notches. The semi-sealing plate is located in the active space.

4. The copper tube diameter changing processing mechanism according to claim 3, characterized in that, A spring is provided within the movable space to connect the semi-sealing plate and the fixed cylinder, and two limiting rings are provided inside the movable cylinder to limit the range of motion of the sealing plate.

5. The copper tube diameter changing processing mechanism according to claim 4, characterized in that, A baffle is provided inside the supply pipe. The baffle and the inner wall of the supply pipe form an air guiding space. The air guiding space is connected to the active space through an air hole one. An air hole two is provided on the outer wall of the supply pipe, which is connected to the air guiding space. The support column is provided with an air passage that communicates with the movable cylinder.

6. The copper tube diameter changing processing mechanism according to claim 3, characterized in that, The arc-shaped edge at one end of the mold parting consists of a guide edge and a movable edge that can slide inside the guide edge. The movable edge is connected to the mold parting by a spring, and the movable edge cooperates with the sealing ring on the support column.

7. The copper tube diameter changing processing mechanism according to claim 3, characterized in that, The position of the sealing ring on the supply pipe along the axis of the supply pipe can be adjusted.

8. The copper tube diameter changing processing mechanism according to claim 3, characterized in that, The sealing ring includes two ring bodies and a rubber sleeve located between the two ring bodies and forming a sealed space with the two ring bodies. The two ring bodies seal the copper tube through the rubber sleeve. One ring body is fixed relative to the corresponding supply pipe or support column, and the other ring body is slidably disposed on the corresponding supply pipe or support column. The other ring body is used for fluid contact between the two sealing rings.

9. A copper tube diameter changing processing mechanism according to claim 8, characterized in that, The inner and outer walls of the rubber sleeve are respectively configured as concave inner and concave outer surfaces, and both ends of the rubber sleeve are configured as slopes facing the outer side of the rubber sleeve.

10. A method for processing copper tubes with varying diameters, employing a copper tube diameter-changing processing mechanism as described in any one of claims 1-9, characterized in that, Includes the following steps: Adjust the position of the two sealing rings on the guide tube so that the distance between the two sealing rings meets the requirements of the copper tube diameter change length; Insert the guide tube and its two sealing rings into the copper tube. The copper tube between the two sealing rings is the variable diameter area. Assemble several sub-molds on the outer support mold on the outer wall of the copper tube so that the two sizing rings on the outer support mold correspond to the two sealing rings. High-pressure fluid is introduced between the two sealing rings through the supply pipe and the guide hole, and the high-pressure fluid externally expands and changes the diameter of the copper pipe. The gas inside the outer support mold is extracted by using a negative pressure pipe, so that a negative pressure is formed around the outer wall of the copper tube diameter change area. The deformation of the copper tube is controlled by the positive and negative pressure difference between the inside and outside of the copper tube. When the outer wall of the copper tube deforms and comes into contact with the inner wall of the outer support mold, the diameter change of the copper tube is completed; Remove the outer support mold and inner support unit, cut the copper tube at the specified position in the diameter change area, and the copper tube processing is completed.

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