Expansion head and pipe expander
By providing a first exhaust hole that penetrates the axially in the guide part of the expansion head, the problem of the smooth inner wall copper tube prone to burst during the expansion tube is solved, and the effect of improving the quality and safety of the expansion tube is achieved.
Patent Information
- Application Number
- CN202421410694.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-19
- Publication Date
- 2025-03-21
- Estimated Expiration
- 2034-06-19
AI Technical Summary
Copper pipes with smooth inner walls are prone to burst during the expansion process, resulting in safety accidents and increased production costs.
An expansion head is designed, including a guide portion and an expansion tube portion, and the guide portion is provided with a first exhaust hole that penetrates the axially to lead out the gas inside the copper tube to avoid bursting caused by gas compression.
By exporting the gas inside the copper tube, gas compression and burst accidents are avoided, and the quality and safety of the expansion tube process are improved.
Smart Images
Figure CN222643048U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of copper tube expansion, in particular to an expansion head and a tube expanding machine. Background Art
[0002] The heat exchanger (evaporator, condenser) of the air conditioner is the core component of the air conditioner. In order to tightly connect the copper tube of the heat exchanger with the corresponding heat exchange structure, the expansion process is used. The copper tube is combined with the corresponding heat exchange structure by expanding the diameter of the copper tube. When expanding the tube, an expansion head with a diameter larger than the inner diameter of the copper tube is inserted into the copper tube, and the expansion head is moved along the axial direction of the copper tube to expand the copper tube outward.
[0003] In order to prevent the copper tube from bursting due to internal gas compression during the expansion process, a tooth-shaped structure is usually provided on the inner wall of the copper tube in the past, so that the gas inside the copper tube can be discharged through the gaps between the teeth.
[0004] In the related art, in order to reduce the material cost of the copper tube, the toothed structure on the inner wall of the copper tube is omitted, which makes the copper tube prone to bursting when the expansion head is used to expand the tube, which may cause safety accidents. Utility Model Content
[0005] The utility model provides an expansion head and a tube expansion machine, which are used to solve the problem that a copper tube with a smooth inner wall is easy to burst during tube expansion.
[0006] In the first aspect, the utility model provides an expansion head, comprising: a tube expander, the tube expander comprising an axially connected guide portion and an expansion portion, the maximum outer diameter of the guide portion is smaller than the inner diameter of the tube to be processed, and the maximum outer diameter of the expansion portion is larger than the inner diameter of the tube to be processed; and a connecting piece for connecting the expansion rod, the connecting piece is connected to the expansion portion, and the connecting piece is coaxially arranged with the tube expander; wherein the guide portion is provided with a first exhaust hole which penetrates the tube expander along the axial direction, and the projection of the first exhaust hole in the axial direction is located on the outside of the connecting piece.
[0007] In one embodiment, the number of the first exhaust holes is at least two.
[0008] In one embodiment, the first exhaust holes are arranged at equal intervals along the circumference of the pipe expansion member.
[0009] In one embodiment, the diameter of the first exhaust hole is less than 0.5 mm.
[0010] In one embodiment, the guide portion is provided with a first hole extending in the radial direction, and the expansion head is further provided with a second hole extending from the connecting member to the guide portion, the second hole extends in the axial direction and passes through the connecting member, and the first hole is communicated with the second hole.
[0011] In one embodiment, the pore size of the first pore is larger than the pore size of the second pore.
[0012] In one embodiment, the outer surfaces of the expansion member are all polished surfaces.
[0013] In one embodiment, the expansion portion is provided with an exit guide surface at one end away from the guide portion, and the radial dimension of the exit guide surface decreases in a direction away from the guide portion.
[0014] In a second aspect, an embodiment of the utility model further provides a tube expander, which includes: a driving device; an expansion rod, which is installed on the driving device; and the above-mentioned expansion head, wherein a connecting piece of the expansion head is detachably connected to the expansion rod.
[0015] In one embodiment, the connecting piece is provided with an external thread, the expansion rod is a hollow structure, and the connecting piece is inserted into the expansion rod and is threadedly connected to the expansion rod.
[0016] Compared with the prior art, the advantage of the utility model is that, by providing a guide portion whose outer diameter is smaller than the inner diameter of the tube to be processed and an expansion portion whose outer diameter is larger than the inner diameter of the tube to be processed, the expansion work of the tube to be processed can be completed in the process of moving the expansion head. A first exhaust hole axially penetrating the expansion piece is provided on the guide portion, and the projection of the first exhaust hole in the axial direction is located outside the connector. The gas inside the tube to be processed can be introduced into the first exhaust hole, and the blocking of the first exhaust hole by the connector and the expansion rod can be avoided, and the gas in the tube to be processed can be guided out by the expansion piece. The formation of compressed gas inside the tube to be processed can be avoided, which can not only improve the processing quality of the expansion process, but also avoid the accident of bursting of the tube to be processed, and improve the safety of the expansion process. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings.
[0018] Figure 1 It is a schematic diagram of the three-dimensional structure of the expansion head in the related art;
[0019] Figure 2 It is a schematic diagram of the main structure of the expansion head in the related art;
[0020] Figure 3 It is a schematic diagram of the main structure when the expansion head is inserted into the tube to be processed in the related art;
[0021] Figure 4 This is a schematic diagram of the main structure of a bulging head provided by an embodiment of the utility model;
[0022] Figure 5 It is a schematic diagram of the main structure of the expansion head provided by the embodiment of the utility model when the guide part is partially extended into the tube to be processed;
[0023] Figure 6This is a schematic diagram of the main structure when the guide part provided by the embodiment of the utility model is fully inserted into the tube to be processed;
[0024] Figure 7 It is a schematic diagram of the main structure when the pipe expansion part provided by the embodiment of the utility model is inserted into the pipe to be processed;
[0025] Figure 8 This is a schematic diagram of the main structure of a bulging head provided by an embodiment of the utility model;
[0026] Fig. 9 This is a schematic diagram of the main structure of a bulging head provided by an embodiment of the utility model;
[0027] Fig.10 It is a schematic diagram of the main structure of the tube expander provided by the embodiment of the utility model;
[0028] Fig.11 It is a schematic diagram of the main structure of the tube expander provided by the embodiment of the utility model when the expansion head is initially inserted into the tube to be processed;
[0029] Fig.12 It is a schematic diagram of the main structure of the tube expander provided by an embodiment of the utility model when the expansion head is fully inserted into the tube to be processed.
[0030] Reference numerals:
[0031] 100, swollen head;
[0032] 110, expansion member; 111, guide portion; 112, expansion portion; 113, first exhaust hole; 114, first hole; 115, second hole; 116, exit guide surface; 117, dividing line;
[0033] 120. Connectors;
[0034] 200, expansion rod;
[0035] 300, driving device;
[0036] 400, expansion device; 410, expansion device; 420, expansion seat; 430, first positioning sleeve;
[0037] 510, die-removing seat; 520, second positioning sleeve;
[0038] 600, balance cylinder;
[0039] 910, pipe to be processed; 920, side plate. DETAILED DESCRIPTION
[0040] The utility model will be further described below in conjunction with the accompanying drawings.
[0041] refer to Figure 1-Figure 3As shown, in the related art, the expansion member 110 of the expansion head 100 is an integrally formed solid structure. When the expansion head 100 is inserted into the tube 910 to be processed, the maximum outer diameter of the expansion head 100 is greater than the inner diameter of the tube 910 to be processed, so as to achieve the expansion of the tube 910 to be processed. However, when the expansion head 100 is inserted into the tube 910 to be processed, the cavity of the tube 910 to be processed is blocked. As the expansion head 100 moves inside the tube 910 to be processed, the gas inside the tube 910 to be processed is compressed. When the gas pressure inside the tube 910 to be processed increases to a certain extent, the tube 910 to be processed is deformed. In severe cases, the tube 910 to be processed may burst, causing a production accident.
[0042] In the past, in order to avoid compression of the gas inside the tube 910 to be processed, a toothed structure is provided on the inner wall of the tube 910 to be processed, and the gaps between the toothed structures are used to guide the gas inside the tube 910 to be processed. However, the cost of providing the toothed structure inside the tube 910 to be processed is high. In order to reduce the cost, some manufacturers hope to provide an expansion head 100 that can adapt to the expansion of a smooth tube.
[0043] See also Figure 4 As shown, an expansion head 100 provided in an embodiment of the utility model is used to expand a tube 910 to be processed.
[0044] The expansion head 100 includes a tube expander 110 and a connector 120, and the tube expander 110 includes a guide portion 111 and a tube expander 112. In this embodiment, the guide portion 111 and the tube expander 112 are integrally formed, and the guide portion 111 and the tube expander 112 are separated by a dividing line 117. The outer diameter of the tube expander 110 at the dividing line 117 is equal to the inner diameter of the tube 910 to be processed. The dividing line 117 here is only used to assist in distinguishing the guide portion 111 from the tube expander 112, and the dividing line 117 may not be designed on the actual expansion head 100.
[0045] When expanding the tube, the end of the tube expander 110 away from the connector 120 is inserted into the tube to be processed 910 (i.e., the guide portion 111 of the tube expander 110 is inserted into the copper tube). Since the maximum outer diameter of the guide portion 111 is smaller than the inner diameter of the tube to be processed 910 (i.e., the copper tube), the tube expander 110 can be easily inserted into the copper tube. When the expansion head 100 is moved axially, the copper tube will be guided by the guide portion 111 to abut against the outer side of the expansion portion.
[0046] Since the maximum outer diameter of the expansion part is larger than the inner diameter of the tube 910 to be processed, the inner wall of the copper tube will expand outwards under the action of the expansion part to complete the expansion work.
[0047] According to the above working process, since the tooth structure of the copper tube is eliminated, the inner wall of the copper tube will be close to the outer wall of the expansion part during the expansion process, so that the gas in the copper tube cannot pass through the expansion head 100. During the movement of the expansion head 100, the gas in the copper tube will be gradually compressed, and the compressed gas may cause the copper tube to deform, and in severe cases, it may cause the copper tube to burst, which not only reduces the production yield, but also may cause safety accidents.
[0048] In order to solve the above problems, in the embodiment of the present application, a first exhaust hole 113 is provided at the guide portion 111, which penetrates the expansion member 110 in the axial direction. Since the maximum outer diameter of the guide portion 111 is smaller than the inner diameter of the tube 910 to be processed, there is a gap between the guide portion 111 and the tube 910 to be processed, and the first exhaust hole 113 penetrating the expansion member 110 can connect the internal air of the copper tube with the external air. When the expansion member 110 is moved, the internal air of the copper tube can be pressed out from the first exhaust hole 113, so as to avoid the copper tube from bursting due to excessive internal air pressure.
[0049] In this embodiment, the first exhaust hole 113 is axially extended, and the first exhaust hole 113 is opened in the guide part 111 whose outer diameter is smaller than the inner diameter of the copper tube. The distance between the two openings of the first exhaust hole 113 and the axis of the expansion member 110 is smaller than the radius of the copper tube. When the copper tube is expanded by the expansion head 100, the two openings of the first exhaust hole 113 will not collide with the inner wall of the copper tube. The connectivity between the gas inside the copper tube and the external gas during expansion is ensured, the formation of compressed gas inside the tube 910 to be processed is avoided, the yield rate of the tube 910 to be processed is improved, and safety accidents in the production process are reduced.
[0050] like Figure 5 and Figure 6 As shown, when the guide portion 111 is partially inserted into the interior of the tube 910 to be processed, and the expansion portion 112 has not yet been inserted into the interior of the tube 910 to be processed, since the maximum outer diameter of the guide portion 111 is smaller than the inner diameter of the tube 910 to be processed, a gap is left between the outer wall of the guide portion 111 and the inner wall of the tube 910 to be processed, so that the gas inside the tube 910 to be processed can flow to the outside through the gap, and at this stage, no compressed gas will be formed inside the tube 910 to be processed. At the same time, the first exhaust hole 113 provided in the guide portion 111 has extended into the interior of the tube 910 to be processed, and the internal cavity of the tube 910 to be processed is connected to the side of the expansion portion 112 away from the guide portion 111 (the right side in the figure) through the first exhaust hole 113.
[0051] refer to Figure 7As shown, when the expansion part 112 extends into the tube 910 to be processed, the inner wall of the tube 910 to be processed will be in close contact with the outer wall of the expansion part 112, and the gas in the tube 910 to be processed will not flow out from the outside of the expansion head 100. Since the outer diameter of the guide part 111 is smaller than the inner diameter of the tube 910 to be processed, and the first exhaust hole 113 is provided at the guide part 111, the tube 910 to be processed is separated from the outer wall of the guide part 111, and the gas in the tube 910 to be processed can flow out from the first exhaust hole 113, thereby avoiding the generation of compressed gas inside the tube 910 to be processed. The processing quality of the tube 910 to be processed is improved, and the occurrence of explosion accidents is avoided, thereby improving the safety of production.
[0052] Moreover, the axial projection of the first exhaust hole 113 is located outside the connecting member 120 (the stud in this embodiment), that is, the distance between the hole wall of the first exhaust hole 113 and the axis of the expansion member 110 is greater than the radius of the stud. The first exhaust hole 113 extends only on the expansion member 110, and there is no need to punch holes in the connecting member 120, which reduces the difficulty of punching holes. Since the first exhaust hole 113 extends only on the expansion member 110, the hole length of the first exhaust hole 113 is less than the axial length of the expansion member 110, the punching length is short, and it is easier to punch holes. Furthermore, since the airflow path of the first exhaust hole 113 is short, even if the first exhaust hole 113 is blocked, the first exhaust hole 113 can be easily cleaned.
[0053] In some embodiments, the guide portion 111 is provided with at least two first exhaust holes 113. The multiple first exhaust holes 113 can increase the gas flow rate, and the compressed gas inside the copper tube can be discharged more quickly to prevent the copper tube from bursting. In this embodiment, the guide portion 111 is provided with two first exhaust holes 113. In other embodiments, the number of the first exhaust holes 113 can be increased or decreased according to the inner diameter of the copper tube and the length of the copper tube. For example, when the inner diameter of the copper tube is large or the length of the copper tube is long, the number of the first exhaust holes 113 can be increased to discharge the compressed gas inside the copper tube more quickly to adapt to the copper tube with a larger internal space.
[0054] In some implementations, the first exhaust holes 113 are evenly spaced around the axis of the expansion member 110. By evenly spaced around the axis, the gas in each area of the copper tube can be discharged to the outside atmosphere at a substantially equal flow rate. And because the first exhaust holes 113 are evenly distributed around the axis, the wind resistance borne by each part of the expansion member 110 is substantially the same, which can prevent the expansion member 110 from being unevenly stressed during the expansion process and causing the axis to deflect or completely rotate.
[0055] See also Figure 4As shown, in some embodiments, the guide portion 111 is provided with two first exhaust holes 113, the two first exhaust holes 113 are spaced 180° apart along the circumference of the guide portion 111, and the two first exhaust holes 113 are spaced equidistant from the axis of the guide portion 111. When the tube is expanded, part of the gas in the copper tube will flow out from the upper first exhaust hole 113, and the other part of the gas will flow out from the lower first exhaust hole 113. It can be understood that the airflow flowing out of the first exhaust hole 113 will generate wind resistance along the axial direction, and since the first exhaust hole 113 is not coaxially arranged with the expansion member 110, the wind resistance will generate a bending moment, which may cause the expansion head 100 to deflect after long-term use. By evenly distributing the first exhaust holes 113 around the axis, the bending moments generated at each first exhaust hole 113 can be balanced with each other, thereby avoiding the deflection of the expansion head 100 and extending the service life of the expansion head 100.
[0056] In some implementations, the diameter of the first exhaust hole 113 is less than 0.5 mm. By setting the diameter of the first exhaust hole 113 to be smaller, it is possible to prevent iron filings from entering the first exhaust hole 113 and blocking the first exhaust hole 113 during the pipe blocking process. In this embodiment, the diameter of the first exhaust hole 113 is 0.3 mm. In other embodiments, the diameter of the first exhaust hole 113 can also be selected to be 0.4 mm or 0.5 mm.
[0057] Continue to refer Figure 7 As shown, in some implementations, the distance between the first exhaust hole 113 and the axis of the expansion member 110 is 2.65 mm, and the diameter of the first exhaust hole 113 is 0.3 mm. The size of the copper tube is Φ7X0.25, that is, the outer diameter of the copper tube is 7 mm, the wall thickness of the copper tube is 0.25 mm, and the inner diameter of the copper tube is 6.5 mm. When the guide portion 111 is inserted into the copper tube, since the maximum distance between the hole wall of the first exhaust hole 113 and the axis of the expansion member 110 is 2.8 mm, which is less than the radius of the copper tube of 3.15 mm, the first exhaust hole 113 will communicate with the internal cavity of the copper tube. The first exhaust hole 113 can guide the internal gas of the copper tube to the end of the expansion portion away from the guide portion 111, thereby avoiding the copper tube from bursting during the expansion process.
[0058] Since the maximum outer diameter of the guide portion 111 is smaller than the inner diameter of the tube 910 to be processed, the copper tube is mainly expanded by the tube expansion portion during the tube expansion process. The first vent hole 113 axially penetrates the tube expansion member 110 from the guide portion 111, and the first vent hole 113 does not affect the outer surface of the tube expansion portion, and the outer surface of the tube expansion portion can be set to a smooth surface, so as to prevent the tube expansion portion from scratching the inner wall of the copper tube during the tube expansion process.
[0059] In some embodiments, Figure 8As shown, the first exhaust hole 113 is a through hole with a constant diameter. In other implementations, the first exhaust hole 113 can also be set as a stepped hole or a tapered hole, wherein the aperture of one end of the guide portion 111 is smaller than the aperture of one end of the expansion portion 112, so that even if foreign matter enters the first exhaust hole 113 through the guide portion 111, the probability of the foreign matter blocking the rear section of the first exhaust hole 113 is also small due to the larger aperture of the rear section of the first exhaust hole 113.
[0060] See also Fig. 9 As shown, in some implementations, the guide portion 111 is provided with a first hole 114 extending in the radial direction, and the expansion head 100 is also provided with a second hole 115 extending from the connecting member 120 (a stud in this embodiment) to the guide portion 111, the second hole 115 extends in the axial direction and passes through the stud, and the first hole 114 is connected to the second hole 115.
[0061] When processing the expansion head 100 , the expansion piece 110 can be welded to the stud first, and then a radially extending first hole 114 is opened at the guide portion 111 , and an axially extending second hole 115 is opened at the end of the stud, and the second hole 115 is connected to the first hole 114 .
[0062] The compressed gas in the copper tube can be guided to the second hole 115 through the first hole 114 opened in the guide portion 111, and flows out of the expansion head 100 from the end of the stud, thereby guiding the gas in the copper tube to avoid the copper tube bursting during the expansion process. For the convenience of subsequent description, the exhaust passage formed by the connection between the first hole 114 and the second hole 115 is called the second exhaust passage.
[0063] When the first exhaust hole 113 is provided, another air flow channel is provided to avoid the difficulty in draining the compressed gas in the copper tube when the first exhaust hole 113 is blocked. In addition, the gas flow rate can be increased through multiple air flow channels, which can better adapt to the work of high-speed tube expansion.
[0064] In this embodiment, the second exhaust passage is in a normally open state, and the first exhaust hole 113 and the second exhaust passage can simultaneously realize exhaust work. In other embodiments, a solenoid valve can be provided at the first hole 114, and the second exhaust passage is set to a normally closed state, and the solenoid valve is opened only when the first exhaust hole 113 is blocked. When the second exhaust passage is opened, an alarm signal is issued to indicate the blockage failure of the first exhaust hole 113.
[0065] Since an electromagnetic valve is provided to prevent the first exhaust hole 113 and the second exhaust passage from being opened at the same time, it is possible to prevent the two exhaust paths from being blocked at the same time, and the second exhaust passage is set to a normally closed state, so that the structure that is blocked first is the first exhaust hole 113 with a shorter path and easier to clean, thereby reducing the difficulty of clearing the blockage.
[0066] In order to discharge the gas in the second hole 115 , a hollow expansion rod 200 may be connected to the connecting piece 120 , so that the gas in the second hole 115 flows into the hollow cavity of the expansion rod 200 and is discharged.
[0067] Since the first hole 114 extends radially to the axis of the guide portion 111 , the second hole 115 can be arranged along the axis of the guide portion 111 to reduce the difficulty of connecting the second hole 115 with the first hole 114 and avoid the first hole 114 and the second hole 115 from being staggered in the radial direction.
[0068] In some implementations, the connector 120 is a stud with external threads, which can be threaded to securely connect the connector 120 to the expansion rod 200. Moreover, the connector 120 can be separated from the expansion rod 200 by rotating the connector 120 in the opposite direction, so that when the expansion head 100 is damaged and needs to be replaced, the expansion head 100 can be easily replaced.
[0069] Since the stud and the expansion member 110 are coaxially arranged, the axis of the stud is colinear with the axis of the guide portion 111. When the second hole 115 extending along the axis of the guide portion 111 actually also extends along the axis of the stud, the difficulty of drilling is relatively low, and the wall thickness of the stud is relatively uniform after drilling, which has little effect on the strength of the external thread of the stud.
[0070] It is understandable that the connector 120 can not only adopt a stud structure with external threads, but also be connected to the expansion rod 200 through a latch structure, or be connected to the expansion rod 200 using a snap-on structure. The specific structure of the connector 120 is not limited here, as long as it can be tightly connected to the expansion rod 200.
[0071] In some implementations, since the first hole 114 extends radially, when the expansion head 100 is installed in the expansion rod 200, a pin can be inserted into the first hole 114 to extend the rotation arm of the expansion head 100, and the expansion head 100 can be tightly threadedly connected to the expansion rod 200 with a smaller tightening force. In other words, the first hole 114 can not only be used to guide the gas, but also can be used to insert a pin-like part to reduce the difficulty of tightening.
[0072] In some implementations, the first hole 114 is a through hole that penetrates the guide portion 111. Compared with setting the first hole 114 as a blind hole, the first hole 114 of the through hole can be better connected with the second hole 115 to avoid the small connection area between the first hole 114 and the second hole 115 due to insufficient depth of the blind hole. In addition, the first hole 114 with a through hole structure can facilitate the insertion of the pin shaft, thereby making it easier to connect or separate the expansion head 100 and the expansion rod 200.
[0073] In addition, since the first hole 114 is a through hole that penetrates the guide portion 111, and the first hole 114 is arranged perpendicular to the second hole 115, when foreign matter such as debris enters the first hole 114, there is a greater probability that the foreign matter will directly escape from the other end of the first hole 114, thereby reducing the probability that the foreign matter enters the second hole 115 and completely blocks the airflow channel.
[0074] See also Fig. 9 As shown, in some implementations, the diameter of the first hole 114 is larger than the diameter of the second hole 115. It is understandable that the diameter of the connecting member 120 is relatively small, and for the sake of connection strength, it is not convenient to use a second hole 115 with a large diameter. By setting the diameter of the first hole 114 to be larger than the diameter of the second hole 115, even if the first hole 114 and the second hole 115 are slightly deviated in the radial direction, the first hole 114 and the second hole 115 can be connected.
[0075] In addition, since the aperture of the first hole 114 is larger than that of the second hole 115 , even if debris enters the first hole 114 , the debris will be prevented from entering due to the smaller aperture of the second hole 115 , thereby reducing the probability of debris being blocked in the second hole 115 .
[0076] In some implementations, the diameter of the first hole 114 is 1.5 mm, and the diameter of the second hole 115 is 1.2 mm. In other implementations, the diameters of the first hole 114 and the second hole 115 can be adjusted according to the inner diameter of the copper tube.
[0077] In some implementations, the expansion member 110 is made of cemented carbide, which has a series of excellent properties such as high hardness, good wear resistance, high strength, and a long service life. Among them, YG8 cemented carbide can be selected.
[0078] In some implementations, the outer surface of the expansion member 110 is a polished surface. By polishing the outer surface of the expansion member 110, the outer burrs of the expansion member 110 are eliminated, and the expansion member 110 will not scratch the inner wall of the copper tube during the expansion process, thereby reducing the production defects of the copper tube. The surface roughness of the polished surface should not exceed Ra3.2μm, and the preferred surface roughness should not exceed Ra0.4μm-Ra0.8μm.
[0079] In some implementations, the expansion member 110 is welded to the connector 120. Specifically, the expansion member 110 and the connector 120 may be welded by projection welding. Resistance welding or drawn arc welding may also be used to weld the expansion member 110 and the connector 120. The specific welding process is not limited here.
[0080] It is understandable that the expansion piece 110 can be connected to the connector 120 not only by welding, but also by integrally forming the expansion piece 110 with the connector 120 (such as integrally casting), which can ensure the connection strength between the expansion piece 110 and the connector 120, and can avoid the axis deviation between the expansion piece 110 and the connector 120 caused by welding error, thereby improving the coaxiality between the expansion piece 110 and the connector 120. Of course, in addition to integrally forming and welding, there are various ways to connect the expansion piece 110 and the connector 120, such as pin connection, plug connection, riveting, etc., as long as the connection strength between the expansion piece 110 and the connector 120 is ensured.
[0081] refer to Figure 8 As shown, the expansion part is provided with an exit guide surface 116 at one end away from the guide portion 111, and the radial dimension of the exit guide surface 116 decreases in the direction away from the guide portion 111. Specifically, the outer diameter of the expansion part 112 is Figure 8 The maximum outer diameter of the expansion part 112 is the first diameter. The diameter of the expansion member 110 gradually decreases in the direction away from the first section, so that an exit guide surface 116 is formed between the first section and the first end surface, wherein the first end surface refers to the end surface of the expansion part 112 away from the guide part 111.
[0082] That is, the radius of the exit guide surface 116 gradually decreases in the direction close to the first end surface, and when the copper tube moves to the exit guide surface 116, the inner wall of the copper tube will separate from the exit guide surface 116 due to the expansion of the inner diameter of the copper tube, so that there is a gap between the inner wall of the copper tube and the exit guide surface 116. Since the exit guide surface 116 is provided, the copper tube can be guided when the expansion head 100 is reversely withdrawn after the tube is removed, so as to avoid scratching the inner wall of the tube 910 to be processed when the expansion head 100 is withdrawn from the tube 910.
[0083] In this embodiment, the outer diameter of the expanded tube portion 112 at the first end face is 6 mm, which is approximately 1 mm smaller than the maximum outer diameter 6.92 mm of the expanded tube portion 112. In other embodiments, the maximum outer diameter of the expanded tube portion 112 and the outer diameter at the first end face can be adjusted according to the inner diameter of the copper tube.
[0084] refer to Fig. 9 As shown, the coaxiality of the expanded tube portion 112 relative to the connector 120 should be less than 0.01 mm. That is, the distance between the axis of the expanded tube portion 112 and the axis of the connector 120 should be within 0.01 mm. This enables the expanded copper tube to be substantially coaxial with the axis of the connector 120.
[0085] The expansion head 100 provided in this embodiment can not only expand the diameter of the tube 910 to be processed so that the tube 910 to be processed can be tightly combined with related components, but also can discharge the gas inside the tube 910 to be processed from the first exhaust hole 113 when the tube 910 to be processed is expanded, so as to avoid the tube 910 to be processed ruptured due to the compression of the gas inside the tube 910.
[0086] See also Fig.10 , Fig.11 and Fig.12 As shown, the utility model further provides a tube expander, which comprises: a driving device 300, an expansion rod 200 and the expansion head 100 in the above embodiment. The expansion rod 200 is installed on the driving device 300, and the connecting piece 120 of the expansion head 100 is detachably connected to the expansion rod 200.
[0087] The driving device 300 can drive the expansion rod 200 to move linearly, so that the expansion head 100 can move along the axis of the tube 910 to be processed, and the expansion work of the tube 910 to be processed is realized. Since the expansion member 110 of the expansion head 100 is provided with a first exhaust hole 113 penetrating therethrough, the gas inside the tube 910 to be processed can be discharged, thereby preventing the tube 910 to be processed from bursting during the expansion process, thereby improving the safety of the expansion process.
[0088] See also Fig.10 As shown, before the tube 910 to be processed (i.e., the copper tube) is expanded, the copper tube is inserted into the hole of the heat exchanger side plate 920. After the expansion, the outer wall of the copper tube can be expanded outward, thereby achieving an interference fit between the side plate 920 and the copper tube.
[0089] Among them, the driving device 300 can use a linear driving component such as a hydraulic cylinder or an electric cylinder to drive the expansion rod 200 to be inserted linearly into the copper tube. Among them, the hydraulic cylinder can not only drive the expansion rod 200 to move linearly, but also provide a large clamping force, so that the expansion head 100 can expand the copper tube more easily. It can be understood that the driving device 300 is not limited to the hydraulic cylinder and electric cylinder mentioned above. In some implementations, the driving device 300 can also be a crank slider movement, and the linear movement of the expansion rod 200 is achieved through a linearly moving slider, or a driving method such as a screw drive is adopted. Other linear driving components that can drive the expansion rod 200 to move linearly are also possible.
[0090] Since the expansion head 100 and the expansion rod 200 are detachably connected, the expansion head 100 can be replaced to complete the subsequent tube expansion work when the expansion head 100 is damaged, which reduces the cost of replacement and maintenance compared to replacing the expansion head 100 and the expansion rod 200. The expansion head 100 and the expansion tube can be connected by threads or pins.
[0091] In some implementations, the tube expander further includes an expansion device 400. After the expansion head 100 is used to expand the copper tube, the expansion device 400 can be used to expand the end opening of the copper tube so that the end of the copper tube is more closely matched with the side plate 920 of the heat exchanger. In this embodiment, the expansion device 400 includes an expansion seat 420, a first positioning sleeve and an expander 410.
[0092] See also Fig.10 As shown, the expander 410 is a sleeve-like structure, which is sleeved outside the expansion rod 200 when in use, and the expander 410 is movably connected to the expansion rod 200. During the expansion process, the expander 410 is first inserted into the copper tube at the bottom, and as the driving device 300 moves further downward, the expander 410 and the expander 410 sleeve above it will bear the downward pressure of the driving device 300. Under the downward pressure of the driving device 300, the expander 410 is driven downward to expand the copper tube.
[0093] See also Fig.10 As shown, the expander 410 is composed of a small head straight pipe section, a tapered expansion section and a large head straight pipe section from low to high, wherein the maximum outer diameter of the expansion head 100 is between the outer diameter of the small head straight pipe section and the outer diameter of the large head straight pipe section. When the expansion head 100 is inserted into the copper tube, the small head straight pipe section will fall into the copper tube. Under the downward pressure of the driving device 300, the expander 410 moves further downward to expand the inner wall of the copper tube outward, and the expansion of the copper tube is achieved during the insertion of the tapered expansion section. Prevent the copper tube from detaching from the side plate 920 of the heat exchanger.
[0094] See also Fig.10 and Fig.11 As shown, when the expansion head 100 enters the interior of the tube 910 to be processed, the tube expander will be separated from the expansion head 100 due to being pressed against the top of the tube 910 to be processed, thereby preventing the tube expander from blocking the first exhaust hole 113 .
[0095] In order to allow the gas in the copper tube to be discharged smoothly, the expander 410 is a hollow structure, and a large gap is left between the expander 410 and the expansion rod 200. In order to avoid the axis of the expander 410 from being offset, resulting in expansion failure of the copper tube. The tube expander also includes an expansion seat 420, on which a first positioning sleeve 430 for positioning the axis of the expander 410 is installed. The side of the expander 410 away from the small head straight tube section is inserted into the first positioning sleeve 430, and the first positioning sleeve 430 is used to position the axis of the expander 410.
[0096] like Fig.10 and Fig.11As shown, the tube expander also includes a die stripping seat 510, on which a second positioning sleeve 520 is installed. When the tube is expanded, the expanded tube and the expansion head 100 are both inserted into the second positioning sleeve 520 on the die stripping seat 510. When the tube expander completes the tube expansion and expansion work, the bottom of the second positioning sleeve 520 is supported on the side plate 920, so that a gap is left between the die stripping seat 510 and the side plate 920, which is convenient for subsequent die stripping.
[0097] refer to Fig.10 and Fig.12 As shown, in some implementations, the tube expander further includes a balancing cylinder 600, which supports the ejection seat 510 and the flaring seat 420 above the ejection seat 510 during tube expansion. The balancing cylinder 600 provides support force to the ejection seat 510 and the flaring seat 420 to prevent the ejection seat 510 from directly pressing down the side plate 920 connected to the tube 910 to be processed. In some implementations, the tube expander is provided with two balancing cylinders 600 to respectively support the opposite ends of the ejection seat 510. Compared with supporting one end of the ejection seat 510 by a single balancing cylinder 600, the opposite ends of the ejection seat 510 can be prevented from being different in height, so that the ejection seat 510 remains horizontal.
[0098] refer to Fig.10 As shown, in some implementations, the driving device 300 is connected to two expansion rods 200, and each expansion rod 200 is correspondingly connected to an expansion head 100. By driving the two expansion heads 100 to move linearly at the same time by the driving device 300, the expansion work of the two tubes 910 to be processed can be realized synchronously, thereby improving the working efficiency of the expansion. The two tubes 910 to be processed processed by the two expansion heads 100 of the two tube expanders in the figure are connected to the same side plate 920, and the expansion of multiple tubes 910 to be processed on the side plate 920 can be completed at one time. Compared with processing different tubes 910 to be processed in steps, synchronously processing multiple tubes 910 to be processed on the side plate 920 can improve the position accuracy between different tubes 910 to be processed on the side plate 920, thereby improving the assembly quality of the heat exchanger.
[0099] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A bulging head, characterized in that: It includes: A pipe expander, the pipe expander comprising an axially connected guide portion and a pipe expansion portion, the maximum outer diameter of the guide portion is smaller than the inner diameter of the pipe to be processed, and the maximum outer diameter of the pipe expansion portion is larger than the inner diameter of the pipe to be processed; as well as A connecting piece for connecting the expansion rod, the connecting piece is connected to the tube expansion part, and the connecting piece is coaxially arranged with the tube expansion piece; The guide portion is provided with a first exhaust hole which penetrates the expansion member in the axial direction, and the projection of the first exhaust hole in the axial direction is located outside the connecting member.
2. The expansion head according to claim 1, characterized in that: The number of the first exhaust holes is at least two.
3. The expansion head according to claim 1 or 2, characterized in that: The first exhaust holes are arranged at equal intervals along the circumference of the pipe expansion member.
4. The expansion head according to claim 1 or 2, characterized in that: The diameter of the first exhaust hole is less than 0.5 mm.
5. The expansion head according to claim 1 or 2, characterized in that: The guide portion is provided with a first hole extending in a radial direction, and the expansion head is further provided with a second hole extending from the connecting member to the guide portion, the second hole extending in an axial direction and penetrating the connecting member, and the first hole is communicated with the second hole.
6. The expansion head according to claim 5, characterized in that: The aperture of the first hole is larger than the aperture of the second hole.
7. The expansion head according to claim 1, characterized in that: The outer surfaces of the expansion pieces are all polished surfaces.
8. The expansion head according to claim 1, characterized in that: The expansion tube portion is provided with an exit guide surface at one end away from the guide portion, and the radial dimension of the exit guide surface decreases in a direction away from the guide portion.
9. A tube expander, characterized in that: It includes: Drive device; An expansion rod, which is mounted on the driving device; as well as The expansion head according to any one of claims 1 to 8, wherein the connecting piece of the expansion head is detachably connected to the expansion rod.
10. The tube expander according to claim 9, characterized in that ； The connecting piece is provided with an external thread, the expansion rod is a hollow structure, and the connecting piece is inserted into the expansion rod and is threadedly connected with the expansion rod.