A pipe expander

Abstract

The expander comprises a fixed jaw handle, a rotating jaw handle, a top pin axially movably arranged at the upper end of the fixed jaw handle, an expander head sleeved outside the conical part, and an elastic band ring sleeved outside all petals of the expander head to drive the petals to inwardly close. A rotating sleeve is sleeved outside the cylindrical part of the top pin, the end of the rotating sleeve is abutted against the fixed jaw handle, a deflection groove with an inclined section or a spiral section is formed in the rotating sleeve, a protruding column is connected to the outer wall of the cylindrical part and is inserted into the deflection groove, and when the rotating jaw handle drives the top pin to axially move, the top pin is forced to circumferentially rotate through the movement of the protruding column along the deflection groove, so that the petals of the expander head are expanded and the expander head is driven to rotate at the same time, the positions of the inner walls of the pipe ends corresponding to the petals during multiple expansion are changed, the stress of the inner walls of the pipe ends in the circumferential direction is uniform, the leakage risk caused by thinning is avoided, and the roundness of the expanded pipe end is ensured, so that the leakage phenomenon during sleeving is avoided.

Description

Technical Field

[0001] This invention relates to the field of tube expansion technology, and more specifically to a tube expander. Background Technology

[0002] When connecting pipes such as metal pipes and plastic pipes, there is a method of connecting them by expanding the opening at the end of the pipe. The expansion operation in this method is usually achieved by using a pipe expander.

[0003] Traditional tube expanders mostly include structures such as a fixed clamp handle, a rotating clamp handle, a split expander head, and a conical pin. For example, Chinese patent CN202655495U discloses such a tube expander. During the tube expansion process, the split of the expander head always corresponds to the same position on the inner wall of the tube end. During multiple expansion processes, the inner wall of the tube end is repeatedly stretched between adjacent splits, causing its thickness to decrease and creating a risk of leakage. At the same time, the tube end of this type of expander has poor roundness after expansion. When the tubes are connected, the gaps between the inner and outer tubes in the circumferential direction are not uniform, which also easily leads to leakage. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a tube expander with good expansion effect and less leakage.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is to fix the clamp handle; A rotating clamp handle whose upper end is rotatably connected to the upper end of the fixed clamp handle; A pin is axially movable at the upper end of the fixed clamp handle. The pin includes a conical portion and a cylindrical portion connected to the large end of the conical portion. The cylindrical portion is hinged to the rotating clamp handle. An expansion head sleeved on the outside of the conical portion, the expansion head comprising a plurality of flaps radially movable and connected to the fixed clamp handle; An elastic band is attached to the outside of all the lobes to drive them inward and close them; A rotating sleeve is fitted on the outer side of the cylindrical part, and the end of the rotating sleeve abuts against the fixed clamp handle. A deflection groove with an inclined section or a spiral section is opened on the rotating sleeve. A protrusion inserted into the deflection groove is connected to the outer wall of the cylindrical part. When the rotating clamp handle rotates and drives the ejector pin to move axially, the protrusion moves along the deflection groove, forcing the ejector pin to rotate circumferentially, thereby expanding all the flaps of the expansion head and driving the expansion head to rotate.

[0006] Preferably, the outer wall of the conical portion is fitted with an outwardly protruding top bead, which is squeezed between adjacent segments when the segments of the expansion tube head are expanded.

[0007] More preferably, the number of the top beads is less than or equal to the number of the lobes and greater than or equal to half the number of the lobes.

[0008] More preferably, the number of lobes is an even number greater than or equal to four, the number of top beads is half the number of lobes, and all the top beads are evenly distributed along the axis of the conical portion.

[0009] More preferably, the volume of the top bead protruding from the outer wall of the conical portion is at most half of the total volume of the top bead, and the outer wall of the conical portion is provided with a receiving hole for accommodating the top bead, and a first elastic element is provided in the receiving hole to drive the top bead to move outward.

[0010] Preferably, a sleeve is connected to the fixed clamp handle and sleeved on the outside of the rotating sleeve. A limiting member is provided at the end of the sleeve away from the fixed clamp handle. The end of the rotating sleeve away from the fixed clamp handle abuts against the limiting member to achieve abutment against the fixed clamp handle.

[0011] More preferably, the end of the sleeve near the fixed clamp handle is provided with an inwardly extending inner annular flange, and an axially movable connecting post is inserted inside the inner annular flange. One end of the connecting post is connected to the cylindrical part, and the other end is hinged to the rotating clamp handle through an adapter.

[0012] More preferably, the end of the sleeve away from the fixed clamp handle is fitted with an end cap, the inner wall of the end cap is provided with an annular groove, and the end of the flap is provided with an outwardly protruding skirt, the skirt being radially movable and embedded in the annular groove.

[0013] Preferably, the deflection groove further has a straight section extending axially along the rotating sleeve, the straight section being located on the side of the rotating sleeve near the fixed clamp handle and penetrating the end face of the rotating sleeve near the fixed clamp handle.

[0014] Preferably, the end face of the protruding post is lower than or flush with the edge of the deflection groove.

[0015] Due to the application of the above-mentioned technical solution, the present invention has the following advantages compared with the prior art: The tube expander provided by this invention includes: a fixed clamp handle, a rotating clamp handle whose upper end is rotatably connected to the upper end of the fixed clamp handle, a pin axially movable at the upper end of the fixed clamp handle, an expander head sleeved on the outside of the conical portion, and an elastic band clamped on the outside of all the segments of the expander head to drive them to close inward. By sleeved on the outside of the cylindrical portion of the pin, the end of the rotating sleeve is pressed against the fixed clamp handle. A deflection groove with an inclined or spiral section is formed on the rotating sleeve, which runs through the wall thickness direction. A protrusion inserted in the deflection groove is connected to the outer wall of the cylindrical portion. When the rotating clamp handle rotates and drives the pin to move axially, the movement of the protrusion along the deflection groove forces the pin to rotate circumferentially. This causes the expander head to rotate while expanding all the segments, changing the position of the inner wall of the tube end corresponding to each segment during multiple expansions. This makes the inner wall of the tube end subjected to uniform force in the circumferential direction, avoiding the risk of leakage caused by thinning, and ensuring the roundness of the expanded tube end, thereby avoiding leakage during sleeve connection. Attached Figure Description

[0016] Figure 1 This is a left-side view of a preferred embodiment of the present invention.

[0017] Figure 2 yes Figure 1 Front view diagram.

[0018] Figure 3 yes Figure 1 A three-dimensional schematic diagram with the fixing clamp handle, sleeve, and end cap removed.

[0019] Figure 4 yes Figure 3 A schematic diagram showing the assembly and disassembly of the expansion tube head and ejector pin.

[0020] Figure 5 yes Figure 2 The cross-sectional view along the AA direction is shown, omitting the fixed clamp handle, rotating clamp handle, and rotating plate.

[0021] Wherein: 10. Fixed clamp handle; 11. Sleeve; 12. Limiting element; 13. Inner annular flange; 131. Connecting post; 14. End cap; 141. Annular groove; 20. Rotating clamp handle; 30. Ejector pin; 31. Conical part; 311. Ejector ball; 312. Receiving hole; 313. First elastic element; 32. Cylindrical part; 321. Protruding post; 33. Rotating plate; 40. Expanding head; 41. Flange; 411. Skirt; 51. First elastic band; 52. Second elastic band; 60. Rotating sleeve; 61. Deflection groove; 611. Inclined section; 612. Straight section; 62. Outer annular flange; 63. Second elastic element. Detailed Implementation

[0022] like Figures 1 to 5As shown, the tube expander provided by the present invention includes: a fixed clamp handle 10, a rotating clamp handle 20, a pin 30, an expander head 40, an elastic retainer, and a rotating sleeve 60; wherein, the upper end of the rotating clamp handle 20 is rotatably connected to the upper end of the fixed clamp handle 10; the pin 30 is axially movable and disposed at the upper end of the fixed clamp handle 10, the pin 30 including a conical portion 31 with the small end facing forward and the large end facing backward and a cylindrical portion 32 connected to the large end of the conical portion 31, the cylindrical portion 32 being hinged to the rotating clamp handle 20; the expander head 40 is sleeved on the outside of the conical portion 31, the expander head 40 including a plurality of flaps 41 that are radially movable and connected to the fixed clamp handle 10; the elastic retainer is clamped on the outside of all the flaps 41 to drive these flaps 41 to close inward; the rotating sleeve 60 is sleeved on the outside of the cylindrical portion 32, and the end of the rotating sleeve 60 abuts against the fixed clamp handle 10. Relative fixation is achieved through the friction of the mating surfaces. The rotating sleeve 60 has a deflection groove 61 that extends along the wall thickness direction and has an inclined section 611. The extension direction of the inclined section 611 is at an angle to the axial direction of the rotating sleeve 60. The outer wall of the cylindrical part 32 is connected to a protrusion 321 inserted in the deflection groove 61. When the rotating clamp 20 rotates and the ejector pin 30 moves axially through the rotating plate 33, the protrusion 321 moves along the deflection groove 61. Under the action of the inclined section 611, the ejector pin 30 is forced to rotate circumferentially. This causes the expansion head 40 to rotate while expanding all the petals 41 of the expansion head 40, thereby changing the position of the inner wall of the tube end corresponding to each petal 41 during multiple expansions. This makes the inner wall of the tube end uniformly stressed in the circumferential direction, avoids the risk of leakage caused by thinning, and ensures the roundness of the tube end after expansion, thus avoiding leakage during sleeve connection.

[0023] To enhance the rotation effect of the ejector pin 30 on each petal 41, a protruding ejector bead 311 is further embedded in the outer wall of the conical portion 31. The volume of the ejector bead 311 protruding from the outer wall of the conical portion 31 is at most half of the total volume of the ejector bead 311. The ejector bead 311 is a retractable elastic ejector bead. Specifically, a receiving hole 312 is provided in the outer wall of the conical portion 31 to accommodate the ejector bead 311. A first elastic element 313 is provided in the receiving hole 312 to drive the ejector bead 311 to move outward. When the petals 41 of the expansion tube head 40 are expanded, the ejector bead 311 follows the forward movement and circumferential rotation of the conical portion 31, squeezes into the gap between adjacent petals 41, and thus gets stuck between adjacent petals 41, forcing the petals 41 to rotate circumferentially. To facilitate the installation of the ejector bead 311, a ball screw is further connected to the receiving hole 312. The steel ball of the ball screw constitutes the ejector bead 311, and the spring in the ball screw constitutes the first elastic element 313.

[0024] The number of top beads 311 needs to match the number of lobes 41 to ensure that the force pushing each lobe 41 in the circumferential direction is approximately equal. When the number of lobes 41 is two or three, the number of top beads 311 should be two or three. When the number of lobes 41 is four, six, or eight, the number of top beads 311 can be four, six, or eight, or two, three, or four. When the number of lobes 41 is five, seven, or nine, the number of top beads 311 is preferably equal to the number of lobes 41, or it can be less than the number of lobes 41, preferably not less than half the number of lobes 41. It should be noted that all lobes 41 are of equal size and are evenly distributed along the axis of the expansion tube head 40. At the same time, all top beads 311 are evenly distributed around the axis of the conical part 31. Specifically, in this embodiment, there are six lobes 41 and three top beads 311, with each pair of lobes 41 forming a group, and each top bead 311 squeezed between two adjacent groups of lobes 41.

[0025] In this embodiment, a sleeve 11 is connected to the fixed clamp handle 10 and sleeved on the outside of the rotating sleeve 60. A limiting member 12 is provided at the end of the sleeve 11 away from the fixed clamp handle 10 (front end). The limiting member 12 is an inner retaining spring that is locked in a groove on the inner wall of the sleeve 11. The end of the rotating sleeve 60 away from the fixed clamp handle 10 (front end) abuts against the limiting member 12, achieving abutment against the fixed clamp handle 10. Simultaneously, the end of the sleeve 11 near the fixed clamp handle 10 (rear end) has an inwardly extending inner annular flange 13, and the end of the rotating sleeve 60 away from the fixed clamp handle 10 (front end) also has an outwardly extending... The outer annular flange 62 and the rotating sleeve 60 are also fitted with a second elastic element 63. The two ends of the second elastic element 63 abut against the inner annular flange 13 and the outer annular flange 62 respectively, so that the front end of the rotating sleeve 60 is kept in a tight abutment with the limiting element 12. When the tube end fails and the petal 41 cannot rotate, the rotating sleeve 60 can follow the rotation to adapt, avoiding damage to the petal 41 and the tube end caused by forcibly rotating the petal 41. In order to avoid interference between the protrusion 321 and the second elastic element 63 when the protrusion 321 moves along the deflection groove 61, the end face of the protrusion 321 is flush with the groove edge of the deflection groove 61.

[0026] To facilitate the rotation of the ejector pin 30, an axially movable connecting post 131 is further provided inside the inner annular flange 13. The front end of the connecting post 131 is connected to the cylindrical part 32, and the rear end is hinged to the rotating clamp handle 20 through an adapter. In this embodiment, the adapter is a rotating plate 33. Specifically, the rear end of the connecting post 131 is hinged to the front end of the rotating plate 33, and the rear end of the rotating plate 33 is hinged to the upper end of the rotating clamp handle 20.

[0027] In this embodiment, the deflection groove 61 also has a straight section 612 extending along the axial direction of the rotating sleeve 60. The straight section 612 is located on the side of the rotating sleeve 60 near the fixed clamp 10 and passes through the end face of the rotating sleeve 60 near the fixed clamp 10. That is, the straight section 612 is connected to the rear end of the inclined section 611 and together with the inclined section 611, forms the deflection groove 61.

[0028] In this embodiment, the end cap 14 is sleeved on the end of the sleeve 11 away from the fixed clamp handle 10 (front end). The inner wall of the end cap 14 is provided with an annular groove 141, and the rear end of the flap 41 is provided with an outwardly protruding skirt 411. The skirt 411 is radially movable and embedded in the annular groove 141.

[0029] In this embodiment, the elastic band includes a first elastic band 51 clamped in the middle of all the petals 41 and a second elastic band 52 clamped on the skirt 411 of all the petals 41. The second elastic band 52 is located in the annular groove 141. The first elastic band 51 and the second elastic band 52 are annular rings formed by springs. Of course, the material and structure of the first elastic band 51 and the second elastic band 52 can also be implemented with reference to the prior art.

[0030] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A tube expander, comprising: Fix the clamp handle; A rotating clamp handle whose upper end is rotatably connected to the upper end of the fixed clamp handle; A pin is axially movable at the upper end of the fixed clamp handle. The pin includes a conical portion and a cylindrical portion connected to the large end of the conical portion. The cylindrical portion is hinged to the rotating clamp handle. An expansion head sleeved on the outside of the conical portion, the expansion head comprising a plurality of flaps radially movable and connected to the fixed clamp handle; An elastic band is attached to the outside of all the lobes to drive them inward and close them; Its features are: A rotating sleeve is fitted on the outer side of the cylindrical part, and the end of the rotating sleeve abuts against the fixed clamp handle. The rotating sleeve has a deflection groove that runs through the wall thickness and has an inclined section or a spiral section. A protrusion inserted into the deflection groove is connected to the outer wall of the cylindrical part. When the rotating clamp handle rotates and drives the ejector pin to move axially, the protrusion moves along the deflection groove, forcing the ejector pin to rotate circumferentially, thereby expanding all the petals and driving the expansion tube head to rotate.

2. The tube expander according to claim 1, characterized in that: The outer wall of the conical portion is fitted with an outwardly protruding top bead, which is squeezed between adjacent lobes when the lobes are expanded.

3. The tube expander according to claim 2, characterized in that: The number of the top beads is less than or equal to the number of the lobes and greater than or equal to half the number of the lobes.

4. The tube expander according to claim 2, characterized in that: The volume of the top bead protruding from the outer wall of the conical portion is at most half the total volume of the top bead. The outer wall of the conical portion is provided with a receiving hole for accommodating the top bead. A first elastic element is provided in the receiving hole to drive the top bead to move outward.

5. The tube expander according to claim 1, characterized in that: A sleeve is connected to the fixed clamp handle and fitted onto the outside of the rotating sleeve. A limiting member is provided at the end of the sleeve away from the fixed clamp handle. The end of the rotating sleeve away from the fixed clamp handle abuts against the limiting member, thereby achieving abutment against the fixed clamp handle.

6. The tube expander according to claim 5, characterized in that: The end of the sleeve near the fixed clamp handle is provided with an inwardly extending inner annular flange. An axially movable connecting post is inserted inside the inner annular flange. One end of the connecting post is connected to the cylindrical part, and the other end is hinged to the rotating clamp handle through an adapter.

7. The tube expander according to claim 6, characterized in that: The rotating sleeve has an outwardly extending outer annular flange at the end away from the fixed clamp handle. A second elastic element is also fitted on the rotating sleeve, with the two ends of the second elastic element respectively abutting against the inner annular flange and the outer annular flange.

8. The tube expander according to claim 5, characterized in that: The end of the sleeve away from the fixed clamp handle is fitted with an end cap, the inner wall of the end cap is provided with an annular groove, the end of the petal is provided with an outwardly protruding skirt, the skirt is radially movable and embedded in the annular groove, the elastic band includes a first elastic band clamped in the middle of all the petals and a second elastic band clamped on the skirt of all the petals.

9. The tube expander according to claim 1, characterized in that: The deflection groove also has a straight section extending axially along the rotating sleeve, the straight section being located on the side of the rotating sleeve near the fixed clamp and penetrating the end face of the rotating sleeve near the fixed clamp.

10. The tube expander according to claim 1, characterized in that: The end face of the protruding post is lower than or flush with the edge of the deflection groove.

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