Thin-wall metal pipe necking die and thin-wall metal pipe necking device

Abstract

The utility model discloses a thin-wall metal pipe necking die and a thin-wall metal pipe necking device adopting the same, the thin-wall metal pipe necking die comprises a rotary lifting mechanism, a thin-wall metal pipe necking die and a clamp, the thin-wall metal pipe necking die comprises a sleeve, a necking assembly and a lubricating assembly, the necking assembly comprises a necking mandrel and a necking threading die, and the lubricating assembly is arranged on the sleeve. When the thin-wall metal pipe is necked down, the clamp clamps the lower end of the thin-wall metal pipe, the rotary lifting mechanism drives the necking die to rotate and move downwards, the upper end of the thin-wall metal pipe enters a gap between the threading die forming part and the mandrel forming part, the upper end of the thin-wall metal pipe is deformed and the pipe diameter is reduced under the rotary extrusion action of the necking die, and a necking part is formed and becomes a reducer pipe. The necked thin-wall metal pipe belongs to the same component and is free of welding seams, the reducing requirement in a pipeline system can be met without introducing a new reducing pipe, welding seams of the pipeline system are effectively reduced, the phenomena of running, emitting, dripping and leaking of the pipeline system are reduced, and the stability and reliability of the pipeline system are improved.

Description

Technical Field

[0001] This utility model relates to the field of tube necking technology, specifically to a thin-walled metal tube necking mold and a thin-walled metal tube necking device using the thin-walled metal tube necking mold. Background Technology

[0002] In hydraulic, refrigeration, and pressurized piping systems, the metal pipes used are typically thin-walled (with a thickness ranging from 0.6mm to 4.0mm). Socket brazing is often required between thin-walled pipes of different diameters, especially for connections between non-standard sizes. For example, in refrigeration unit production, connections between thin-walled copper pipes of different diameters are frequently encountered. The copper pipe diameter at the compressor exhaust pipe interface is smaller than that of the exhaust pipe. The common practice is to first insert a reducer (a type of pipe fitting used to connect two pipes of different diameters, commonly known as a "reducer," which can be concentric or eccentric) into the pipe end, and then braze the two together. The drawback is that the use of the reducer adds a new weld seam. This additional weld seam reduces production efficiency and increases the unreliability of the piping system, leading to leaks and reduced system stability. Summary of the Invention

[0003] In view of this, the technical problem to be solved by this utility model is to provide a thin-walled metal tube necking mold and a thin-walled metal tube necking device using the thin-walled metal tube necking mold, which can neck the end of the thin-walled metal tube without the need to weld the reducing pipe to meet the diameter change requirements, reduce welds, reduce the running, dripping and leaking phenomena of the pipeline system, and improve the system stability.

[0004] To solve the aforementioned technical problems regarding necking dies for thin-walled metal tubes, the technical solution of this utility model is: a necking die for thin-walled metal tubes, comprising: a sleeve, a necking assembly, and a lubrication assembly; the necking assembly is disposed within the sleeve and includes a necking mandrel and a necking die, the necking die being located in the lower part of the sleeve and fixed to the sleeve, and the inner wall surface of the necking die being provided with a die forming portion for forming the outer wall surface of the neck of the thin-walled metal tube; the necking mandrel is a stepped shaft, including a shoulder, a lower section of the mandrel located below the shoulder, and a section located on the... The upper section of the mandrel above the shoulder has a mandrel forming part on its outer peripheral surface for forming the inner wall of the necked-off metal tube. The mandrel forming part corresponds to the die forming part, and there is a gap between them. The lubrication assembly includes an oil seal and a lubricating oil groove. The oil seal is sleeved on the lower section of the mandrel and clamped between the bottom surface of the shoulder and the top of the necked-off die. The lubricating oil groove is fixed to the outside of the sleeve and forms a lubricating oil pool between the sleeve and the sleeve. The sleeve is provided with a connecting oil passage that connects the lubricating oil pool to the inside of the sleeve.

[0005] The die forming part includes a plurality of internal teeth spaced apart, with a groove between adjacent internal teeth, both ends of the internal teeth being arc-shaped guide sections, a straight section between two arc-shaped guide sections, and the working surface of the internal teeth being a smooth surface.

[0006] The lower section of the mandrel has several longitudinal oil channels spaced apart on its outer circumferential surface. The upper end of each longitudinal oil channel passes through the lower part of the shoulder to form an oil passage notch in the shoulder. The mandrel forming part is located between adjacent longitudinal oil channels. An internal oil cavity is formed between the outer circumferential surface of the shoulder and the inner wall of the sleeve. The oil passage notch in the shoulder connects the internal oil cavity with the longitudinal oil channels.

[0007] The bottom surface of the shoulder is recessed with a chamfered cutting edge for removing burrs from the end of the thin-walled metal pipe, and the chamfered cutting edge is located between two adjacent oil passage notches of the shoulder.

[0008] The mandrel forming part is provided with grooves.

[0009] The necking die and the sleeve are fixedly connected by a set screw.

[0010] The sleeve is provided with a threaded through hole, the outer wall of the necked die is provided with a tapered hole, the set screw is connected to the threaded through hole of the sleeve, the tip of the set screw abuts against the tapered hole of the die, and the center line of the tapered hole of the die is lower than the center line of the set screw.

[0011] The thin-walled metal tube necking die also includes a die handle, which is hollow at least at the bottom. The lower end of the die handle is provided with an internal thread and an external thread. The upper section of the mandrel is provided with a stud section, and the internal thread of the die handle is threadedly connected to the upper section of the mandrel. The upper inner wall surface of the sleeve is provided with an internal thread, and the external thread of the die handle is connected to the internal thread of the sleeve.

[0012] The mold handle has a limiting groove on its outer circumferential surface and a square upper end.

[0013] To solve the aforementioned technical problems regarding the necking device for thin-walled metal tubes, the technical solution of this utility model is: a necking device for thin-walled metal tubes, comprising: a rotary lifting mechanism, wherein the bottom of the rotary lifting mechanism is provided with the aforementioned thin-walled metal tube necking mold, and a clamp is provided below the thin-walled metal tube necking mold; the rotary lifting mechanism is a rotary lifting mechanism of a bench drill, machining center, or CNC machine tool.

[0014] After adopting the above technical solution, the beneficial technical effects achieved by this utility model are as follows:

[0015] The thin-walled metal tube necking device of this utility model includes a rotary lifting mechanism, a thin-walled metal tube necking mold, and a clamp. The thin-walled metal tube necking mold includes a sleeve, a necking assembly, and a lubrication assembly. The necking assembly includes a necking mandrel and a necking die disposed in the sleeve. When the thin-walled metal tube is necked at the end using the thin-walled metal tube necking device, the clamp holds the lower end of the thin-walled metal tube, and the rotary lifting mechanism drives the thin-walled metal tube necking mold to rotate downward. The upper end of the thin-walled metal tube enters the gap between the die forming part and the mandrel forming part. Under the rotational extrusion action of the thin-walled metal tube necking mold, the upper end of the thin-walled metal tube deforms and the tube diameter decreases, forming a neck and becoming a reducing pipe. Since the necked thin-walled metal tube belongs to the same component and has no weld seam, there is no need to use a new reducing pipe to meet the diameter requirement in the pipeline system. This effectively reduces the weld seams in the pipeline system, helps to reduce the running, leaking, dripping, and seeping phenomena in the pipeline system, and improves the stability and reliability of the pipeline system. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the external structure of the thin-walled metal tube necking mold according to an embodiment of the present invention;

[0017] Figure 2 This is a cross-sectional schematic diagram of the thin-walled metal tube necking die according to an embodiment of the present invention (in the state of rotating and extruding the thin-walled metal tube);

[0018] Figure 3 This is a schematic diagram of the thin-walled metal tube necking device according to an embodiment of the present invention for necking a thin-walled metal tube;

[0019] Figure 4 yes Figure 2 A schematic diagram showing the assembly of the sleeve, necked mandrel, oil seal, and lubricating oil groove.

[0020] Figure 5 yes Figure 2 A schematic diagram of the necked mandrel structure in the diagram;

[0021] Figure 6 yes Figure 5 Enlarged diagram of point A in the diagram;

[0022] Figure 7 yes Figure 2 A schematic diagram showing the positional relationship between the necking die, oil seal, and necking mandrel in the diagram.

[0023] Figure 8 yes Figure 2 A top view of the necked-out tooth;

[0024] Figure 9 yes Figure 2 A schematic diagram of the mold handle structure;

[0025] Figure 10 This is a schematic diagram of a thin-walled metal tube before necking.

[0026] Figure 11 This is a schematic diagram of a thin-walled metal tube after necking.

[0027] In the diagram: I. Thin-walled metal tube necking die; II. Rotary lifting mechanism; III. Fixture;

[0028] 1. Necked mandrel; 11. Shoulder; 111. Chamfered cutting edge; 12. Lower section of mandrel; 121. Longitudinal oil passage; 1211. Oil passage notch in shoulder; 122. Mandrel forming part; 1221. Groove; 13. Upper section of mandrel;

[0029] 2. Oil seal;

[0030] 3. Necked die; 31. Die forming part; 311. Internal tooth; 3111. Arc-shaped guide section; 3112. Straight section; 32. Groove; 33. Die tapered hole;

[0031] 4. Sleeve; 41. Connecting oil passage; 42. Sleeve threaded through hole; 4a. Lubricating oil sump; 4b. Internal oil cavity;

[0032] 5. Lubricating oil tank;

[0033] 6. Mold shank; 61. Upper end of mold shank; 62. Limiting groove; 63. Mold shank shoulder; 64. Internal thread of mold shank; 65. External thread of mold shank;

[0034] 7. Set screw;

[0035] 8. Thin-walled metal tube; 81. Neck constriction. Detailed Implementation

[0036] It should be noted that, in this description, unless otherwise specified or limited, the terms “connected,” “linked,” “interconnected,” etc., should be interpreted broadly, and can refer to a direct connection between two components or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0037] The embodiments of this utility model will now be described in further detail and without limitation, with reference to the accompanying drawings.

[0038] Example 1

[0039] like Figure 1 , Figure 2 , Figures 4 to 9 As shown in the figure, the thin-walled metal tube necking mold of this utility model includes: a sleeve 4, a necking assembly, and a lubrication assembly. The necking assembly is disposed inside the sleeve 4 and includes a necking mandrel 1 and a necking die 3. The necking die 3 is located in the lower part of the sleeve 4 and is fixed to the sleeve 4. A die forming part 31 for forming the outer wall surface of the neck of the thin-walled metal tube is provided on the inner wall surface of the necking part. The necking mandrel 1 is a stepped shaft, including a shoulder 11, a lower mandrel section 12 located below the shoulder 11, and an upper mandrel section 13 located above the shoulder 11. A mandrel forming part 122 for forming the inner wall surface of the neck of the thin-walled metal tube is provided on the outer peripheral surface of the lower mandrel section 12. The mandrel forming part 122 and the die forming part 31 are positioned correspondingly, and there is a gap between them. The lubrication assembly includes an oil seal 2 and a lubricating oil groove 5. The oil seal 2 is sleeved on the outer periphery of the lower section 12 of the spindle and there is a gap between it and the lower section 12 of the spindle. The oil seal 2 is clamped between the bottom surface of the shoulder 11 and the top of the necked die 3. The lubricating oil groove 5 is fixed to the outside of the sleeve 4 and forms a lubricating oil pool 4a between it and the sleeve 4. A connecting oil passage 41 is provided on the sleeve 4 to connect the lubricating oil pool 4a with the inside of the sleeve 4. The connecting oil passage 41 is optimized to be an inclined oil passage.

[0040] like Figure 7 and Figure 8 As shown, the die forming part 31 includes a plurality of spaced-apart internal teeth 311, with grooves 32 between adjacent internal teeth. Both ends of the internal teeth are provided with arc-shaped guide sections 3111, and a straight section 3112 is formed between two arc-shaped guide sections 3111. The working surface of the internal teeth is a smooth surface and is not threaded. This differs from the working surface of a conventional die, which is provided with working threads.

[0041] like Figure 4 and Figure 5As shown, a number of longitudinal oil channels 121 are provided at intervals on the outer peripheral surface of the lower section 12 of the mandrel. The upper end of the longitudinal oil channel 121 passes through the lower part of the shoulder 11 to form an oil passage notch 1211 in the shoulder. The mandrel forming part 122 is located between adjacent longitudinal oil channels 121. An internal oil cavity 4b is formed between the outer peripheral surface of the shoulder 11 and the inner wall surface of the sleeve 4. The oil passage notch 1211 in the shoulder connects the internal oil cavity 4b with the longitudinal oil channel 121.

[0042] like Figure 5 and Figure 6 As shown, the bottom surface of the shoulder portion 11 is recessed with a chamfered cutting edge 111 for removing burrs from the end of the thin-walled metal pipe, and the chamfered cutting edge 111 is located between two adjacent oil passage notches 1211 of the shoulder portion.

[0043] The mandrel forming part is provided with a groove 1221, which can reduce the force and friction of the necked mandrel during processing.

[0044] like Figure 2 , Figure 4 and Figure 7 As shown, the necked die 3 and the sleeve 4 are fixedly connected by a set screw 7 (preferably a flat-end set screw). Specifically, the sleeve 4 is provided with a sleeve threaded through hole 42, and the outer wall surface of the necked die 3 is provided with a die tapered hole 33. The set screw 7 is connected to the sleeve threaded through hole 42, and the tip of the set screw 7 abuts against the die tapered hole 33. The center line of the die tapered hole 33 is slightly lower than the center line of the set screw 7, ensuring that the die tapered hole 33 is always subjected to an upward force after being tightened by the set screw 7, thus ensuring the sealing of the overlapping end faces of each component.

[0045] like Figure 2 and Figure 9 As shown, the thin-walled metal tube necking die also includes a die shank 6. The die shank 6 is designed with a hollow structure at least at its lower part. The die shank 6 is generally cylindrical in shape. A die shank shoulder 63 is provided on the outer periphery of the die shank 6. An external die shank thread 65 is provided on the outer periphery of the die shank 6 below the die shank shoulder 63. An internal die shank thread 64 is provided inside the die shank 6. The upper section 13 of the mandrel is set as a stud section, and the internal die shank thread 64 is threadedly connected to the upper section 13 of the mandrel. An internal sleeve thread is provided on the upper inner wall surface of the sleeve 4, and the external die shank thread 65 is connected to the internal sleeve thread. A limiting groove 62 is provided on the outer periphery of the die shank to facilitate quick clamping with the drill shank of the rotary lifting mechanism described below. The upper end 61 of the die shank is set as a square structure to avoid relative rotation with the drill shank of the rotary lifting mechanism.

[0046] When assembling a thin-walled metal tube necking die, the upper section 13 of the necking mandrel 1 is fastened to the inner thread 64 of the die shank 6 via a right-hand thread; the sleeve 4 is fastened to the necking die drill shank via a right-hand thread ...

[0047] Example 2

[0048] like Figure 3 As shown, and with reference Figure 2 , Figure 10 , Figure 11 The thin-walled metal tube necking device of this utility model embodiment can be installed on equipment such as a bench drill, machining center, or CNC machine tool, and includes: a rotary lifting mechanism II, which is the rotary lifting mechanism of the bench drill, machining center, or CNC machine tool. A thin-walled metal tube necking mold I as described above is provided at the bottom of the rotary lifting mechanism II, and a clamp III is provided below the thin-walled metal tube necking mold I for clamping the tube.

[0049] Taking a bench drill as an example, when necking pipe fittings, Figure 10 The lower end of the thin-walled metal tube 8 shown is clamped and fixed by clamp III. The bench drill is started, and the drill chuck drives the thin-walled metal tube necking die I to rotate. The drill handle is cranked, causing the thin-walled metal tube necking die I to move slowly downwards. The upper end of the thin-walled metal tube 8 enters the gap between the mandrel forming part 122 and the die forming part 31. Under the action of rotational extrusion, the upper end of the thin-walled metal tube 8 deforms, the tube diameter decreases, forming a neck 81. Figure 11 As shown, a reducing pipe is manufactured. During the processing, the lubricating oil in the lubricating oil pool 4a enters the internal oil cavity 4b through the connecting oil passage 41, and enters the longitudinal oil passage 121 through the oil passage notch 1211 on the shoulder, lubricating the inner and outer walls of the metal pipe to be necked, providing good lubrication and cooling during the necking process. During the processing, when the upper end of the necked neck 81 reaches the chamfered cutting edge 111 recessed on the bottom surface of the shoulder 11 of the necking mandrel 1 through the gap between the oil seal 2 and the lower section 12 of the mandrel, the chamfered cutting edge 111 can effectively remove the burrs at the upper end of the necked neck 81. When the reducing pipe is used in a pipeline system, it can prevent leakage and improve the connection quality.

[0050] The above description is an example of a preferred embodiment of the present utility model. All parts not described in detail are known technologies in the art. The protection scope of the present utility model is determined by the content of the claims. Any equivalent transformations based on the technical teachings of the present utility model are within the protection scope of the present utility model.

Claims

1. A necking die for a thin-walled metal tube, characterized in that, The thin-walled metal tube necking die includes: a sleeve, a necking assembly, and a lubrication assembly; The necking assembly is disposed within the sleeve and includes a necking mandrel and a necking die. The necking die is located in the lower part of the sleeve and is fixed to the sleeve. The inner wall surface of the necking die is provided with a die forming part for forming the outer wall surface of the neck of the thin-walled metal tube. The necking mandrel is a stepped shaft, including a shoulder, a lower mandrel section located below the shoulder, and an upper mandrel section located above the shoulder. The outer circumferential surface of the lower mandrel section is provided with a mandrel forming part for forming the inner wall surface of the neck of the thin-walled metal tube. The mandrel forming part and the die forming part are positioned correspondingly, and there is a gap between them. The lubrication assembly includes an oil seal and a lubricating oil groove. The oil seal is sleeved on the lower section of the mandrel and clamped between the bottom surface of the shoulder and the top of the necked die. The lubricating oil groove is fixed to the outside of the sleeve and forms a lubricating oil pool between the sleeve and the sleeve. The sleeve is provided with a connecting oil passage that connects the lubricating oil pool to the inside of the sleeve.

2. The thin-walled metal tube necking die as described in claim 1, characterized in that, The die forming part includes a plurality of internal teeth spaced apart, with a groove between adjacent internal teeth, both ends of the internal teeth being arc-shaped guide sections, a straight section between two arc-shaped guide sections, and the working surface of the internal teeth being a smooth surface.

3. The thin-walled metal tube necking die as described in claim 1, characterized in that, The lower section of the mandrel has several longitudinal oil channels spaced apart on its outer circumferential surface. The upper end of each longitudinal oil channel passes through the lower part of the shoulder to form an oil passage notch in the shoulder. The mandrel forming part is located between adjacent longitudinal oil channels. An internal oil cavity is formed between the outer circumferential surface of the shoulder and the inner wall of the sleeve. The oil passage notch in the shoulder connects the internal oil cavity with the longitudinal oil channels.

4. The thin-walled metal tube necking die as described in claim 3, characterized in that, The bottom surface of the shoulder is recessed with a chamfered cutting edge for removing burrs from the end of the thin-walled metal pipe. The chamfered cutting edge is located between two adjacent oil passage notches on the shoulder.

5. The thin-walled metal tube necking die as described in claim 3, characterized in that, The mandrel forming part is provided with grooves.

6. The thin-walled metal tube necking die as described in claim 1, characterized in that, The necked die and the sleeve are fixedly connected by set screws.

7. The thin-walled metal tube necking die as described in claim 6, characterized in that, The sleeve is provided with a sleeve threaded through hole, and the outer wall surface of the necked die is provided with a die tapered hole. The set screw is connected to the sleeve threaded through hole, the tip of the set screw abuts against the die tapered hole, and the center line of the die tapered hole is lower than the center line of the set screw.

8. The thin-walled metal tube necking die as described in claim 1, characterized in that, The thin-walled metal tube necking die also includes a die handle, which is hollow at least at the bottom. The lower end of the die handle is provided with an internal thread and an external thread. The upper section of the mandrel is provided with a stud section, and the internal thread of the die handle is threadedly connected to the upper section of the mandrel. The upper inner wall surface of the sleeve is provided with an internal thread, and the external thread of the die handle is connected to the internal thread of the sleeve.

9. The thin-walled metal tube necking die as described in claim 8, characterized in that, The outer circumferential surface of the mold handle is provided with a limiting groove, and the upper end of the mold handle is square.

10. A necking device for a thin-walled metal tube, characterized in that, The thin-walled metal tube necking device includes: a rotary lifting mechanism, wherein the bottom of the rotary lifting mechanism is provided with a thin-walled metal tube necking mold as described in any one of claims 1 to 9, and a clamp is provided below the thin-walled metal tube necking mold; the rotary lifting mechanism is a rotary lifting mechanism of a bench drill, machining center or CNC machine tool.

Images