Method for forming return air duct, forming die and return air duct

Abstract

The application relates to the technical field of refrigeration equipment, and provides a forming method of a return air pipe, a forming die and the return air pipe. The forming method of the return air pipe comprises the following steps: controlling a blank to enter a forming cavity, controlling a die core to extrude the blank, making the blank pass through a first die body, and obtaining a first length value of a first formed pipe segment formed through the first die body; determining whether the first length value reaches a first set parameter value, controlling a second die body to extrude part of the first formed pipe segment, making part of the first formed pipe segment be formed into a second formed pipe segment, and obtaining a second length value of the second formed pipe segment; determining whether the second length value reaches a second set parameter value, and controlling the second die body to stop extruding; and controlling a third formed pipe segment formed by the first die body to reach a third set parameter value. The application can continuously extrude multiple pipe segments with different cross-sectional shapes, so that the multiple pipe segments are integrally formed, the welding points between the adjacent two pipe segments are cancelled, and the leakage risk of the return air pipe is reduced.

Description

Technical Field

[0001] This application relates to the field of refrigeration equipment technology, and in particular to a method for forming a return gas pipe, a forming mold, and a return gas pipe. Background Technology

[0002] Heat exchange tubes used in refrigeration equipment typically consist of a return gas tube and a capillary tube. The return gas tube has a circular cross-section and is fixed to the capillary tube for heat exchange via aluminum foil, heat shrink tubing, or similar materials. The return gas tube and capillary tube are in linear contact, resulting in relatively low heat exchange efficiency.

[0003] To improve heat exchange efficiency, capillary tubes are embedded in the return gas pipe. Related technologies add circular cross-section connecting pipes at both ends of the return gas pipe, which connect to the evaporator and compressor.

[0004] Although adding connecting pipes at both ends of the return pipe can connect the return pipe to the evaporator and compressor, the weld between the connecting pipe and the return pipe is prone to leakage at the weld seam, which increases the risk of leakage of the return pipe in the foam layer of the refrigeration equipment, thus affecting the reliability of the refrigeration equipment. Summary of the Invention

[0005] This application aims to at least solve one of the technical problems existing in the related art. To this end, the first aspect of this application provides a method for forming a return gas pipe, which can continuously extrude to form return gas pipes with different cross-sectional shapes, with good cross-sectional consistency, while meeting the heat exchange and connection requirements of the return gas pipe.

[0006] The second aspect of this application provides a molding die.

[0007] The third aspect of this application provides a return gas pipe.

[0008] The method for forming a return gas pipe according to the embodiments of this application includes:

[0009] The blank is controlled to enter the forming cavity, and the mold core is controlled to squeeze the blank so that the blank passes through the first mold body, and the first length value of the first forming tube segment formed by the first mold body is obtained.

[0010] Once the first length value is determined to reach the first set parameter value, the second mold body is controlled to extrude a portion of the first forming tube segment, so that the portion of the first forming tube segment is formed into a second forming tube segment, and the second length value of the second forming tube segment is obtained.

[0011] Once the second length value is determined to reach the second set parameter value, the second mold body is controlled to stop extrusion.

[0012] The third forming tube segment formed by the first mold body is controlled to reach the third set parameter value;

[0013] The cross-sectional shape of the first mold is different from that of the second mold.

[0014] According to the forming method of the return gas pipe according to the embodiments of this application, multiple pipe segments with different cross-sectional shapes can be continuously extruded, thereby forming multiple pipe segments into one piece. This eliminates the weld points between adjacent pipe segments and reduces the risk of leakage in the return gas pipe. It ensures the consistency of the return gas pipe's cross-section while meeting its heat exchange and connection requirements.

[0015] According to one embodiment of this application, in the step of determining that the first length value has reached the first set parameter value, if the starting end of the first formed tube segment is found to have reached the first preset position, then the first length value is determined to have reached the first set parameter value.

[0016] According to one embodiment of this application, in the step of controlling the second mold body to extrude a portion of the first forming tube segment, forming the portion of the first forming tube segment into a second forming tube segment, and obtaining a second length value of the second forming tube segment, if the starting end of the first forming tube segment reaches a second preset position, then it is determined that the second forming tube segment has reached the second set parameter value.

[0017] The first preset position and the second preset position are located in the conveying direction of the first formed pipe section, and the second preset position is located downstream of the first preset position.

[0018] According to one embodiment of this application, in the step of controlling the third forming tube segment of the first mold body to reach the third set parameter value, if the starting end of the first forming tube segment reaches the third preset position, then it is determined that the third forming tube segment has reached the third set parameter value.

[0019] The first preset position and the third preset position are located in the conveying direction of the first formed pipe section, and the third preset position is located downstream of the first preset position.

[0020] According to one embodiment of this application, in the step of controlling the second mold body to extrude a portion of the first forming tube segment, so that the portion of the first forming tube segment is formed into a second forming tube segment, and obtaining a second length value of the second forming tube segment,

[0021] Once the second mold body is located in the mold closing position, the first forming tube segment is controlled to move at a preset speed for a preset time, and the second length value is obtained based on the preset speed and the preset time.

[0022] According to the molding die provided in this application, a molding method for performing the return pipe as described in any of the above claims is provided, comprising a mold core, a first mold body and a second mold body, wherein a molding cavity is formed between the mold core and the first mold body;

[0023] The second mold body is located on the discharge end side of the first mold body. The second mold body includes a first sub-mold body and a second sub-mold body located on one side of the first sub-mold body. The first sub-mold body or the second sub-mold body is provided with a protrusion, and the protrusion faces the center of the second mold body.

[0024] According to one embodiment of this application, at least one of a first position sensor, a second position sensor, and a third position sensor is provided on the side of the second mold body facing away from the first mold body;

[0025] The first position sensor is used to detect that the starting end of the first formed tube segment reaches a first preset position; the second position sensor is used to detect that the starting end of the first formed tube segment reaches a second preset position; and the third position sensor is used to detect that the starting end of the first formed tube segment reaches a third preset position.

[0026] According to one embodiment of this application, the protrusion is disposed on the first sub-mold body, and a driving mechanism is connected to the first sub-mold body; the driving mechanism adapts the first sub-mold body to switch between a first position and a second position.

[0027] At the first position, the first sub-mold body is separated from the second sub-mold body, and there is a set distance between the first sub-mold body and the second sub-mold body;

[0028] In the second position, the first sub-mold body and the second sub-mold body are joined together.

[0029] According to one embodiment of this application, a fourth position sensor and a fifth position sensor are provided on the moving path of the drive mechanism;

[0030] The fourth position sensor is used to detect that the first sub-mold body is located at the position where it is closed with the second sub-mold body;

[0031] The fifth position sensor is used to detect that the first sub-mold body is located at a position separated from the second sub-mold body.

[0032] According to the molding die provided in the embodiments of this application, return air pipes with different cross-sectional shapes can be continuously extruded to meet the production requirements of continuous extrusion of return air pipes; at the same time, the formed return air pipes have stable dimensions, good cross-sectional consistency, simple molding process, and convenient operation.

[0033] The return pipe provided in this application includes a first pipe segment, a second pipe segment, and a third pipe segment formed by extrusion molding. The second pipe segment is located between the first pipe segment and the second pipe segment. The second pipe segment is configured with a receiving portion, which is recessed toward the center of the second pipe segment and extends along the axial direction of the second pipe segment.

[0034] According to the return gas pipe provided in this application, the first pipe section, the second pipe section and the third pipe section are integrally formed, and the second pipe section is constructed with a receiving part, which not only increases the contact area between the return gas pipe and the capillary tube and improves the heat exchange efficiency, but also facilitates the connection of the return gas pipe, eliminates the welding point between two adjacent formed pipe sections, and reduces the leakage risk of the return gas pipe.

[0035] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0036] To more clearly illustrate the technical solutions in the embodiments or related technologies of this application, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0037] Figure 1 This is a schematic flowchart of the method for forming a return air pipe provided in an embodiment of this application;

[0038] Figure 2 This is a schematic flowchart of the method for forming a return air pipe provided in an embodiment of this application;

[0039] Figure 3 This is one of the cross-sectional views of the molding die provided in the embodiments of this application;

[0040] Figure 4 yes Figure 3 A view along direction A;

[0041] Figure 5 This is a second cross-sectional view of the molding die provided in the embodiments of this application;

[0042] Figure 6 yes Figure 5 A view along direction B in the middle;

[0043] Figure 7 This is one of the forming schematic diagrams of the forming method of the return air pipe provided in the embodiments of this application;

[0044] Figure 8 This is a second schematic diagram of the forming method of the return pipe provided in the embodiments of this application;

[0045] Figure 9 This is a schematic diagram of the return air pipe provided in the embodiment of this application.

[0046] Figure label:

[0047] 10. Return pipe; 11. First pipe section; 12. Second pipe section; 13. Gradient pipe section; 14. Third pipe section;

[0048] 20. Molding mold; 21. First mold body; 211. First sub-mold body; 212. Second sub-mold body; 213. First mold cavity; 22. Second mold body; 221. Third sub-mold body; 222. Fourth sub-mold body; 223. Protrusion; 224. Second mold cavity; 23. Mold core; 231. Molding part; 232. Recessed part; 24. Drive mechanism; 25. Drive assembly; 26. Blank. Detailed Implementation

[0049] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but should not be used to limit the scope of this application.

[0050] In the description of the embodiments of this application, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application based on the specific circumstances.

[0052] In the embodiments of this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0053] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0054] See details Figures 3 to 6 One aspect of this application provides a molding die, including a mold core 23, a first mold body 21 and a second mold body 22, wherein a molding cavity is formed between the mold core 23 and the first mold body 21.

[0055] like Figure 4 and Figure 6 As shown, in order to facilitate the processing of the first mold body 21, the first mold body 21 can be configured as a split structure, that is, the first mold body 21 includes a first sub-mold body 211 and a second sub-mold body 212. After the first sub-mold body 211 and the second sub-mold body 212 are joined together, they are used for the initial extrusion molding of the tube.

[0056] The second mold body 22 is located on the discharge end side of the first mold body 21. The second mold body 22 includes a third sub-mold body 221 and a fourth sub-mold body 222 located on one side of the third sub-mold body 221. The third sub-mold body 221 or the fourth sub-mold body 222 is provided with a protrusion 223. The protrusion 223 is arranged towards the center of the second mold body 22. After the third sub-mold body 221 and the fourth sub-mold body 222 are closed, at least one depression can be formed on the surface of the tube that has been squeezed by the second mold body 22.

[0057] It can be understood that the first mold body 21 is used to form the entire return air pipe 10, and the second mold body 22 is located at the rear end of the first mold body 21. That is, the second mold body 22 is located on the side where the pipe section formed by the first mold body 21 extends. On the entire pipe body formed by the first mold body 21, a recess is formed in a local part of the pipe body, that is, an irregular cross-sectional structure. It is equivalent to the second mold body 22 being formed again on the basis of the first mold body 21.

[0058] In some embodiments of this application, such as Figure 4 and Figure 6 As shown, a protrusion 223 is provided on the side of the second mold body 22 facing the blank 26. Specifically, the protrusion 223 can be formed on either the third sub-mold body 221 or the fourth sub-mold body 222, that is, either the third sub-mold body 221 or the fourth sub-mold body 222 has a protrusion 223 corresponding to the recessed structure facing the center of the second mold body 22.

[0059] When the protrusion 223 is provided on the third sub-mold body 221, the corresponding drive mechanism 24 is connected to the third sub-mold body 221; when the protrusion 223 is provided on the fourth sub-mold body 222, the corresponding drive mechanism 24 is connected to the fourth sub-mold body 222; when the protrusion 223 is provided on both the third sub-mold body 221 and the fourth sub-mold body 222, the corresponding drive mechanisms 24 are connected to the third sub-mold body 221 and the fourth sub-mold body 222 respectively.

[0060] In some embodiments of this application, the drive mechanism 24 may include a cylinder and its connecting pipe, or the drive mechanism 24 may include an oil cylinder and its connecting pipe, etc. Any drive component that can achieve linear reciprocating movement to control the third sub-mold body 221 to close with the fourth sub-mold body 222 and to separate from the fourth sub-mold body 222 is acceptable.

[0061] In some embodiments of this application, preferably, the drive mechanism 24 and the protrusion 223 are disposed on the same component, that is, the drive mechanism 24 is connected to the third sub-mold body 221. Under the action of the drive mechanism 24, the third sub-mold body 221 can move relative to the fourth sub-mold body 222 and is suitable for switching between the first position W1 and the second position W2.

[0062] At the first position W1, as Figure 6As shown, the third sub-mold body 221 and the fourth sub-mold body 222 are closed, that is, the third sub-mold body 221 moves downward relative to the fourth sub-mold body 222 to the position of the fourth sub-mold body 222. At this time, the billet 26 is extruded by the first mold body 21 to form a tube with a circular cross section, and then extruded by the second mold body 22 to form a receiving part with an embedded capillary, which is the second formed tube segment with an irregular cross section. At this time, the first mold body 21 and the second mold body 22 cooperate with the extrusion equipment to continuously extrude the circular cross section tube segment and the irregular cross section tube segment.

[0063] At the second position W2, as Figure 4 As shown, the third sub-mold body 221 separates from the fourth sub-mold body 222, that is, the third sub-mold body 221 moves upward relative to the fourth sub-mold body 222 to a set distance. This set distance can be an interval value, that is, as long as the third sub-mold body 221 does not interfere with the blank 26 being extruded into a tube with a circular cross-section; the set distance can also be a fixed value, at which the third sub-mold body 221 does not interfere with the blank 26 being extruded into a tube with a circular cross-section.

[0064] At this time, the billet 26 is extruded by the first mold body 21 to form a tube with a circular cross section. The fourth sub-mold body 222 in the second mold body 22 is only used for support. Therefore, the first mold body 21 and the second mold body 22 work together with the extrusion equipment to extrude a tube segment with a circular cross section. This is equivalent to the second mold body 22 retaining the tube structure formed by the first mold body 21.

[0065] During the switching from the second position W2 to the first position W1, the drive mechanism 24 controls the third sub-mold body 221 to gradually move closer to the fourth sub-mold body 222, so that a gradient pipe section 13 connecting two pipe sections with different cross-sectional shapes is formed on the return pipe 10.

[0066] like Figure 7 and Figure 8 As shown in some embodiments of this application, at least one of a first position sensor, a second position sensor, and a third position sensor is provided at intervals at the rear end of the molding die 20. That is, the first position sensor, the second position sensor, and the third position sensor are provided at intervals on the side of the second mold body 22 facing away from the first mold body 21. The second position sensor can be arranged between the first position sensor and the third position sensor.

[0067] The first position sensor is used to detect that the starting end of the return air pipe 10 has reached the first preset position and outputs a signal to the control system to control the second mold body 22 to move closer to the blank 26 and start the extrusion operation.

[0068] That is, such as Figure 8 and Figure 9As shown, on one side of the protruding forming mold 20, along the conveying path of the return air pipe 10, according to the length design requirements of the return air pipe 10, a first position sensor is set at the corresponding position of the first set parameter value L1. When the starting end of the return air pipe 10 reaches the position of the first position sensor, it indicates that the length of the circular cross-section pipe segment meets the requirements of the first set parameter value L1. The first position sensor transmits a signal to the control system. After receiving the signal, the control system causes the second mold body 22 to gradually approach the blank 26 until the blank 26 is squeezed to form an irregular cross-section pipe segment.

[0069] The second position sensor is used to detect that the starting end of the return air pipe 10 has reached the second preset position, and outputs a signal to the control system to control the second mold body 22 to move away from the blank 26 and stop the extrusion operation.

[0070] That is, along the conveying path of the return air pipe 10, downstream of the first position sensor, according to the length design requirements of the return air pipe 10, the second position sensor is set at the corresponding position of the second set parameter value L2. When the starting end of the return air pipe 10 reaches the position of the second position sensor, it means that the length of the irregular cross-section pipe segment meets the requirements of the second set parameter value L2. The second position sensor transmits a signal to the control system. After receiving the signal, the control system makes the second mold body 22 gradually move away from the blank 26.

[0071] The third position sensor is used to detect when the starting end of the return air pipe 10 reaches the third preset position, completing one cycle of the return air pipe 10 forming process. At this time, it is equivalent to the ending end of the return air pipe 10 being located at the first preset position.

[0072] That is, along the conveying path of the return air pipe 10, according to the length design requirements of the return air pipe 10, a third position sensor is set at the corresponding position of the third set parameter value L3. When the starting end of the return air pipe 10 reaches the position of the third position sensor, it means that the length of the circular cross-section pipe segment meets the requirements of the third set parameter value L3. The third position sensor transmits a signal to the control system to complete the forming of the return air pipe 10 in one cycle.

[0073] In some embodiments of this application, the first mold body 21 may also be an integral structure, and the first mold body 21 is disposed on the extrusion equipment. The ingot is divided into several streams of metal under pressure in the extrusion equipment (which may be a metal extruder), enters the welding chamber through the diversion hole, converges in the welding chamber, and is re-welded under high temperature, high pressure, and high vacuum environment, and finally flows out through the gap between the first mold body 21 and the mold core 23 to extrude and form a tube with a circular cross section.

[0074] In some embodiments of this application, such as Figure 4 and Figure 6As shown, in order to improve the forming accuracy of the irregular cross-section pipe segment, a driving component 25 is connected to the mold core 23 to drive the mold core 23 to translate so that part of the mold core 23 enters the second mold cavity 224. At the same time, the mold core 23 has a forming part 231 and a recessed part 232. The forming part 231 cooperates with the first mold body 21 to extrude the first mold body 21 to form a pipe segment with a circular cross-section. The recessed part 232 is nested with the protrusion 223 on the second mold body 22 to improve the accuracy of the extrusion forming and make it easier to assemble with the capillary.

[0075] like Figure 4 and Figure 6 As shown, the inlet of the first mold cavity 213 is shaped like an "eight" and can guide the blank 26 so that the blank 26 flows into the gap between the first mold body 21 and the mold core 23.

[0076] In the use of the forming mold 20 of the return air pipe 10 provided in this application embodiment, the driving mechanism 24 is controlled by the main program of the extrusion equipment. When the length of the pipe segment with a circular cross-section extruded by the first mold body 21 is determined, the driving mechanism 24 drives the third sub-mold body 221 to move downward and close with the fourth sub-mold body 222, extruding the pipe segment with a circular cross-section formed by the extrusion of the first mold body 21, so that a depression is formed on the extruded part of the pipe segment. After the length of the depression is determined, the driving mechanism 24 drives the third sub-mold body 221 to move upward and separate from the fourth sub-mold body 222, so that the pipe segment with a circular cross-section extruded by the first mold body 21 is retained.

[0077] In some embodiments of this application, a fourth position sensor and a fifth position sensor are provided on the moving path of the drive mechanism 24;

[0078] The fourth position sensor is used to detect that the third sub-mold body 221 of the drive mechanism 24 is in the position where it is closed with the fourth sub-mold body 222, so as to ensure that the drive mechanism 24 drives the third sub-mold body 221 to move into place and avoid the poor forming of the recessed structure.

[0079] The fifth position sensor is used to detect the drive mechanism 24. The third sub-mold body 221 is located at a position separated from the fourth sub-mold body 222 and has a set distance between them, ensuring that the third sub-mold body 221 leaves the end of the second forming tube section.

[0080] In some embodiments of this application, the first, second, third, fourth, and fifth position sensors described above can all include contact sensors and proximity sensors.

[0081] Contact sensors include microswitches. When the formed tube segment moves and encounters a microswitch, its internal contacts will activate, thereby outputting a signal.

[0082] Proximity sensors include electromagnetic sensors, photoelectric sensors, differential transformer sensors, eddy current sensors, capacitive sensors, reed switch sensors, Hall effect sensors, etc. Preferably, this embodiment uses a photoelectric sensor, which outputs a signal when the starting end of each formed tube segment approaches a set distance.

[0083] According to the molding die 20 of the present application embodiment, it can continuously extrude and form return air pipes 10 with different cross-sectional shapes to meet the production requirements of continuous extrusion of return air pipes 10; at the same time, the dimensions of return air pipes 10 are stable, the cross-sectional consistency is good, the molding die 20 is simple to control and easy to operate.

[0084] See details Figure 1 and Figure 2 Based on the above-mentioned molding die 20, the molding method of the return air pipe 10 provided in this application includes the following steps:

[0085] Step S101: Control the blank 26 to enter the forming cavity, and control the mold core to squeeze the blank 26 so that the blank 26 passes through the first mold body, and obtain the first length value of the first forming tube segment formed by the first mold body;

[0086] That is, the blank 26 is fed into the gap between the first mold body 21 and the mold core 23, and the mold core 23 is moved in the first mold cavity 213 of the first mold body 21 through a certain extrusion stroke to extrude the blank 26, forcing the blank 26 to undergo directional plastic deformation and be extruded from the first mold body 21 or continuously extruded from the first mold body 21 to the second mold body 22.

[0087] Step S102: Determine that the first length value reaches the first set parameter value L1, control the second mold body 22 to extrude part of the first forming tube segment, so that part of the first forming tube segment is formed into the second forming tube segment, and obtain the second length value of the second forming tube segment.

[0088] In some embodiments of this application, such as Figure 2 As shown, in the step of determining that the first length value has reached the first set parameter value L1, if the starting end of the first formed tube segment is found to have reached the first preset position, it can be determined that the first length value has reached the first set parameter value L1.

[0089] That is, such as Figure 7 As shown, the position of the starting end of the first forming tube segment extruded from the first mold body 21 is detected by the first position sensor, and the second mold body 22 is controlled to start the extrusion operation, and the second forming tube segment is formed by continuous extrusion at the rear end of the first forming tube segment.

[0090] The first length value is the actual length of the first forming tube segment extruded through the first mold body 21. The cross-sectional shape of the first forming tube segment is circular. A position sensor (photoelectric sensor or micro switch) can be set according to the length requirement of the circular cross-section tube segment. When the starting segment of the extruded circular cross-section tube segment reaches the position of the position sensor, it is determined that the length of the circular cross-section tube segment meets the requirements.

[0091] Then, the drive mechanism 24 is controlled to push the third sub-mold body 221 closer to the fourth sub-mold body 222 and close with it. To ensure a better forming effect for the formed tube segment, the drive mechanism 24 descends slowly, thus continuously forming a gradient tube segment 13 on a portion of the first formed tube segment. After the third sub-mold body 221 and the fourth sub-mold body 222 close, the forming of the irregular cross-section tube segment, i.e., the forming of the second formed tube segment, begins.

[0092] Step S103: Determine that the second length value has reached the second set parameter value L2, and control the second mold body 22 to stop extrusion.

[0093] When detecting the second length value of the second forming tube segment after being extruded by the second mold body 22, it can be carried out in the following manner:

[0094] The first implementation method, such as Figure 2 As shown, in the step of controlling the second mold body 22 to extrude part of the first forming tube segment, so that part of the first forming tube segment is formed into the second forming tube segment, and obtaining the second length value of the second forming tube segment, if the starting end of the first forming tube segment is found to have reached the second preset position, then it is determined that the second forming tube segment has reached the second set parameter value L2.

[0095] The first preset position and the second preset position are located in the conveying direction of the first formed pipe section, and the second preset position is located downstream of the first preset position.

[0096] That is, by detecting the position of the starting end of the second forming tube segment extruded by the second mold body 22 through the second position sensor, it can be determined that when the second length value reaches the second set parameter value L2, the second mold body 22 stops extruding and the first mold body 21 continues to extrude. At this time, the tube structure with a circular cross section formed by the extrusion of the first mold body 21 is maintained, so that the rear end of the second forming tube segment is continuously extruded to form the third forming tube segment.

[0097] like Figure 8As shown, at least one position sensor is installed along the transport path of the return air pipe 10. In this embodiment, a first position sensor can be installed at point a on the transport path of the return air pipe 10, corresponding to the starting end of the return air pipe 10; a second position sensor can be installed at point b on the transport path of the return air pipe 10, corresponding to the starting end of the second forming pipe segment in the return air pipe 10; and a third position sensor can be installed at point c on the transport path of the return air pipe 10, corresponding to both the starting and ending ends of the return air pipe 10. By collecting the position information of each point, the forming length of each forming pipe segment is determined.

[0098] Alternatively, six position points can be set along the exit length of the forming pipe segment along the movement path of the return air pipe 10 to obtain six corresponding position signals: the starting end of the first forming pipe segment, the ending end of the first forming pipe segment, the starting end of the second forming pipe segment, the ending end of the second forming pipe segment, the starting end of the third forming pipe segment, and the ending end of the third forming pipe segment. By collecting the position information of each point, the forming length of each forming pipe segment can be determined.

[0099] In the second embodiment, in the step of controlling the second mold body 22 to extrude part of the first forming tube segment, so that part of the first forming tube segment is formed into the second forming tube segment, and obtaining the second length value of the second forming tube segment, if the second mold body is found to be in the mold closing position, the first forming tube segment is controlled to move at a preset speed for a preset time, and the second length value is obtained based on the preset speed and the preset time.

[0100] That is, by detecting the starting end of the first forming tube segment through the first position sensor, the drive mechanism 24 is controlled to push the third sub-mold body 221 closer to the fourth sub-mold body 222 and close the mold with the fourth sub-mold body 222. The closing of the mold between the third sub-mold body 221 and the fourth sub-mold body 222 is detected by the fourth position sensor set on the moving path of the drive mechanism 24. At this time, the timer can be used to count to a set time, which is determined according to the target length of the second forming tube segment and the feeding speed. After the set time is reached, the drive mechanism 24 is driven back to separate the third sub-mold body 221 and the fourth sub-mold body 222, and the second length value can also be obtained.

[0101] like Figure 4 and Figure 6As shown, during the process of forming the second forming tube segment, there are two position signals on the movement path of the drive mechanism 24: one confirming that the third sub-mold body 221 has penetrated to position W1, and the other confirming that the third sub-mold body 221 has withdrawn to position W2. Timing begins when the third sub-mold body 221 gradually penetrates to position W1. After the time is determined according to the length requirement of the irregular cross-section tube segment, the third sub-mold body 221 is controlled to gradually withdraw to position W2, ending the forming of the second forming tube segment (irregular cross-section tube segment) and entering the forming of the circular cross-section tube segment.

[0102] Step S104: Control the third forming tube segment of the first mold body to reach the third set parameter value L3;

[0103] In some embodiments of this application, such as Figure 2 As shown, in the step of controlling the third forming tube segment formed by the first mold body 21 to reach the third set parameter value L3, if it is obtained that the starting end of the first forming tube segment reaches the third preset position, then it is determined that the third forming tube segment has reached the third set parameter value L3; wherein, the first preset position and the third preset position are located in the conveying direction of the first forming tube segment, and the third preset position is located downstream of the first preset position.

[0104] That is, such as Figure 8 As shown, the first mold body 21 stops extrusion and cuts off the formed return air pipe 10 after the third position sensor detects that the starting end of the first forming pipe segment has reached its position. Alternatively, the first mold body 21 can continue to work after the formed return air pipe 10 has been cut off.

[0105] The cross-sectional shape of the first mold is different from that of the second mold. This cross-section refers to the longitudinal cross-sectional shape of the first mold body and the second mold body, that is, the cross-sectional shape perpendicular to the axis of the return air pipe.

[0106] In the above steps, the first length value, the second length value, and the third length value are the actual lengths of the corresponding formed pipe segments of the return pipe measured during the processing; the first set parameter value L1, the second set parameter value L2, and the third set parameter value L3 are the forming lengths of the corresponding formed pipe segments, that is, the first set parameter value L1, the second set parameter value L2, and the third set parameter value L3 are the target lengths of each formed pipe segment in the return pipe 10 according to the design drawings, that is, the reference lengths of each formed pipe segment in the actual production process.

[0107] This molding method can be understood as continuously extruding multiple pipe segments with different cross-sectional shapes, thus forming multiple pipe segments into a single piece. This eliminates the weld points between adjacent pipe segments and reduces the risk of leakage in the return gas pipe. It ensures the consistency of the return gas pipe's cross-section while meeting its heat exchange and connection requirements.

[0108] like Figure 9 As shown, one aspect of this application also provides a return air pipe 10, including a first pipe section 11, a second pipe section 12, a tapered pipe section 13 and a third pipe section 14 formed by extrusion molding. The second pipe section 12 is located between the first pipe section 11 and the third pipe section 14. The two ends of the second pipe section 12 are respectively connected to the first pipe section 11 and the third pipe section 14 through the tapered pipe section 13. The second pipe section 12 is constructed with a receiving portion, which is recessed toward the center of the second pipe section 12 and extends along the axial direction of the second pipe section 12.

[0109] Wherein, the first pipe segment 11 and the gradient pipe segment 13 correspond to the starting end of the first formed pipe segment to the starting end of the second formed pipe segment, the second pipe segment 12 corresponds to the second formed pipe segment, and the third pipe segment 14 and the gradient pipe segment 13 correspond to the ending end of the second formed pipe segment and the ending end of the third formed pipe segment.

[0110] The first pipe section 11 and the third pipe section 14 are adapted to be connected to the connecting pipes provided in the evaporator and the compressor, respectively, and the second pipe section 12 is formed with a receiving portion for embedding the capillary tube.

[0111] Essentially, the first pipe section 11 and the third pipe section 14 are used to connect the connecting pipes located in the evaporator and the compressor, respectively; the capillary tube is wrapped in the receiving part, which can increase the contact area between the capillary tube and the return pipe 10; all pipe sections are integrally formed, and there are no welding points between two adjacent pipe sections, which can ensure the sealing of the entire return pipe 10 and effectively prevent leakage of the return pipe 10.

[0112] It is understood that the return gas pipe 10 provided in this application is integrally formed with all pipe sections, and a receiving part for embedding the capillary is formed in the second pipe section 12. This not only increases the contact area between the return gas pipe 10 and the capillary to improve heat exchange efficiency, but also facilitates the connection between the return gas pipe 10 and the connecting pipe, eliminates the welding point between two adjacent pipe sections, and reduces the leakage risk of the return gas pipe 10.

[0113] Currently, the heat exchange tubes used in the refrigeration systems of refrigerators or freezers are generally aluminum return pipes 10 and copper capillary tubes, with the aluminum return pipe 10 having a circular cross-section. The return pipe 10 is fixed to the capillary tube by aluminum foil, heat shrink tubing, etc. After being fixed in this way, the return pipe 10 and the capillary tube are in linear contact, with a small contact area and low thermal efficiency.

[0114] To address this, related technologies extend the length of the return pipe 10 to increase the contact area between the return pipe 10 and the capillary tube, thereby improving heat exchange efficiency. However, this significantly increases the material and manufacturing costs of the return pipe 10, increases system costs, and reduces market competitiveness.

[0115] Therefore, in some related technologies, the capillary tube is fully or partially buried inside the return gas pipe 10 to increase the contact area between the return gas pipe 10 and the capillary tube, thereby improving the heat exchange efficiency. Since the two ends of the return gas pipe 10 with its irregular cross-section structure cannot be directly connected to the evaporator and compressor, in related technologies, circular cross-section connecting pipes are welded to both ends of the irregular cross-section structure and then connected to the evaporator and compressor.

[0116] The above-mentioned arrangement adds two solder joints (brazing or resistance soldering) at the connection between the return gas pipe 10 and the evaporator and compressor, which increases the risk of leakage of the return gas pipe 10 within the foam layer and reduces the reliability of the system.

[0117] Therefore, the return gas pipe 10 provided in this application has a first section with a circular cross-section at the beginning, a second section with an irregular cross-section in the middle, and a first section with a circular cross-section at the end. That is, the cross-sectional shape of the return gas pipe 10 changes from circular to irregular and then back to circular. This structure not only increases the contact area between the return gas pipe 10 and the capillary tube, improving heat exchange efficiency, but also facilitates the connection between the return gas pipe 10 and the connecting pipe, thereby eliminating weld points on the return gas pipe 10, reducing the risk of system leakage, and improving system reliability. Furthermore, this structural design reduces the material and manufacturing costs of the return gas pipe 10, enhancing the pipe's market competitiveness.

[0118] Finally, it should be noted that the above embodiments are only used to illustrate this application and are not intended to limit this application. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application and should be covered within the scope of the claims of this application.

Claims

1. A method for forming a return air pipe, characterized in that, include: The blank is controlled to enter the forming cavity, and the die core is controlled to squeeze the blank, so that the blank passes through the first die body, and the first length value of the first forming tube segment formed by the first die body is obtained; the blank is conveyed into the gap between the first die body and the die core, and the die core is moved in the first die cavity of the first die body through a certain extrusion stroke to squeeze the blank, forcing the blank to produce directional plastic deformation and be extruded from the first die body, and the first length value is the actual length of the first forming tube segment extruded by the first die body; Once the first length value is determined to reach the first preset parameter value, the second mold body is controlled to extrude a portion of the first forming tube segment, so that the portion of the first forming tube segment is formed into a second forming tube segment, and the second length value of the second forming tube segment is obtained; once the second mold body is determined to be in the mold closing position, the first forming tube segment is controlled to move at a preset speed for a preset time, and the second length value is obtained based on the preset speed and the preset time; Once the second length value is determined to reach the second set parameter value, the second mold body is controlled to stop extruding, while the first mold body continues to extrude, maintaining the tube structure with a circular cross-section formed by the extrusion of the first mold body, so that the rear end of the second formed tube segment is continuously extruded to form the third formed tube segment; The third forming tube segment formed by the first mold body is controlled to reach the third set parameter value; The cross-sectional shape of the first mold is different from that of the second mold.

2. The method for forming a return air pipe according to claim 1, characterized in that, In the step of determining that the first length value reaches the first set parameter value... If the starting end of the first formed tube segment reaches the first preset position, then the first length value is determined to have reached the first set parameter value.

3. The method for forming a return air pipe according to claim 2, characterized in that, In the step of controlling the second mold body to extrude a portion of the first forming tube segment, so that the portion of the first forming tube segment is formed into a second forming tube segment, and obtaining the second length value of the second forming tube segment, If the starting end of the first formed pipe segment reaches the second preset position, then it is determined that the second formed pipe segment has reached the second set parameter value; The first preset position and the second preset position are located in the conveying direction of the first formed pipe section, and the second preset position is located downstream of the first preset position.

4. The method for forming a return air pipe according to claim 2, characterized in that, In the step of controlling the third forming tube segment of the first mold body to reach the third set parameter value... If the starting end of the first formed pipe segment reaches the third preset position, then it is determined that the third formed pipe segment has reached the third preset parameter value. The first preset position and the third preset position are located in the conveying direction of the first formed pipe section, and the third preset position is located downstream of the first preset position.

5. A molding die, characterized in that, A method for forming a return air pipe according to any one of claims 1 to 4 includes a mold core, a first mold body, and a second mold body, wherein a forming cavity is formed between the mold core and the first mold body; The second mold body is located on the discharge end side of the first mold body. The second mold body includes a third sub-mold body and a fourth sub-mold body located on one side of the third sub-mold body. The third sub-mold body or the fourth sub-mold body is provided with a protrusion, which faces the center of the second mold body.

6. The molding die according to claim 5, characterized in that, At least one of a first position sensor, a second position sensor, and a third position sensor is provided on the side of the second mold body facing away from the first mold body; The first position sensor is used to detect that the starting end of the first formed tube segment reaches a first preset position; the second position sensor is used to detect that the starting end of the first formed tube segment reaches a second preset position; and the third position sensor is used to detect that the starting end of the first formed tube segment reaches a third preset position.

7. The molding die according to claim 5, characterized in that, The protrusion is provided on the third sub-mold body, and a driving mechanism is connected to the third sub-mold body; the driving mechanism makes the third sub-mold body suitable for switching between a first position and a second position. At the first position, the third sub-mold body is separated from the fourth sub-mold body, and there is a set distance between them; In the second position, the third sub-mold body and the fourth sub-mold body are joined together.

8. The molding die according to claim 7, characterized in that, A fourth position sensor and a fifth position sensor are provided on the moving path of the drive mechanism; The fourth position sensor is used to detect that the third sub-mold body is located at the position where it is closed with the fourth sub-mold body; The fifth position sensor is used to detect that the third sub-mold body is located at a position separated from the fourth sub-mold body.

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