Working assembly of pipe expansion tool and electric hydraulic pipe expansion tool

Abstract

The present invention belongs to the technical field of tube expansion tools, and particularly refers to a working component of a tube expansion tool and an electric hydraulic tube expansion tool, wherein the working component includes a sleeve, a tube expansion mold, and an ejector pin, wherein the ejector pin is inserted into the middle of the sleeve, and the front end of the ejector pin can be extended into the tube expansion mold, so that the tube expansion mold is opened for operation; a curved groove is provided on the peripheral surface of the ejector pin along its length direction, and a rotating component is provided inside the sleeve, and a positioning portion is provided on the inner side of the rotating component, and at least part of the positioning portion is embedded in the curved groove, so that the linear motion of the ejector pin is converted into the circumferential rotation of the rotating component; the front end of the rotating component is connected to the tube expansion mold and drives it to rotate. The purpose of the present invention is to provide a working component of a tube expansion tool, wherein a rotating component is provided between the tube expansion mold and the ejector pin, and the tube expansion mold not only expands under the drive of the ejector pin, but also rotates at a certain angle, so that the tube mouth can be fully stressed during the process of expanding the tube mouth, and the expansion quality of the tube mouth is greatly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of pipe expanding tools, and in particular relates to a working component of a pipe expanding tool and an electric hydraulic pipe expanding tool. Background Art

[0002] Pipe expansion tools are mainly used in pipeline connection and other aspects. When used, it is usually necessary to expand the connection hole at one end of the pipe fitting first, then insert the other pipe fitting into the expanded connection hole, and then use a crimping tool to press the two pipe fittings to complete the pipeline connection. Existing pipe expansion tools such as a hydraulic pipe expander proposed in Chinese utility model patent CN 203944741U, whose pipe expansion mold is directly connected to the outside of the ejector pin, and the pipe expansion mold is composed of multi-petal cone claws, and there is a gap between each cone claw. When working, the cone claw is extended into the pipe fitting connection hole, and the piston located in the pump body is pushed by the oil, thereby pushing the ejector pin, causing the cone claw to open outward to achieve the effect of expanding the pipe fitting hole.

[0003] In the actual working process, the expansion degree of the expansion tool in one work is limited. Usually, the pipe fitting needs to be expanded multiple times to expand the connecting hole to the required size. Although the above technical scheme can achieve the effect of pipe expansion, there is a gap between adjacent cone claws. After being stretched open by the ejector during work, the gap will become larger. Therefore, the side of the cone claw is easy to leave marks on the inner wall of the pipe fitting, and due to the existence of the gap, the outer periphery of the pipe expansion mold is not a perfect circle. After repeated pipe expansion, it is easy to cause the connecting hole on the inside of the pipe fitting to become a polygonal hole or unilateral expansion or irregular pipe mouth, etc. Such situation will cause the sealing of the connection between the pipe mouth and the pipeline to be greatly affected, which will bring more trouble to the installation and construction. Summary of the invention

[0004] The object of the present invention is to provide a working component of a pipe expanding tool, which is provided with a rotating component between a pipe expanding die and an ejector pin. In addition to expanding under the drive of the ejector pin, the pipe expanding die also rotates at a certain angle, so that the pipe mouth can be fully stressed during the process of expanding the pipe mouth, thereby greatly improving the expansion quality of the pipe mouth, and an electric hydraulic pipe expanding tool provided with such a working component.

[0005] The object of the present invention is achieved in that:

[0006] A working component of a tube expansion tool comprises a sleeve body; a tube expansion mold, which is arranged at the front end of the sleeve body; an ejector pin, which is inserted into the middle of the sleeve body, and the front end of the ejector pin can be extended into the tube expansion mold, so that the tube expansion mold is opened for operation; a curved groove is opened on the circumferential surface of the ejector pin along its length direction, a rotating component is arranged inside the sleeve body, a positioning portion is arranged on the inner side of the rotating component, and at least part of the positioning portion is embedded in the curved groove, so that the linear motion of the ejector pin is converted into the circumferential rotation of the rotating component; the front end of the rotating component is connected to the tube expansion mold and drives it to rotate.

[0007] It is further configured that the rotating component is sleeved on the outside of the ejector pin, and a mounting groove is provided on the inside of the rotating component; the positioning part is a steel ball, one side of the steel ball is embedded in the mounting groove, and the other side of the steel ball is embedded in the curved groove.

[0008] It is further configured that the rotating component includes

[0009] A driving block, which is sleeved on the outer periphery of the ejector pin and is provided with the mounting groove;

[0010] A rotating block, one end of which is provided with a ratchet ring sleeved on the outer circumference of the driving block, and the other end is sleeved on the outer circumference of the ejector pin and connected to the tube expansion mold; a plurality of ratchet teeth are provided on the inner side of the ratchet ring, and a pawl cooperating with the ratchet teeth is provided on the driving block; a spring with one end against one side of the pawl is provided in the driving block.

[0011] It is further configured that the ratchet ring and the rotating block are separately or integrally configured. When they are separately configured, the ratchet ring is fixed to the rotating block by a fixing pin.

[0012] It is further configured that a support ring is provided on the inner side of the rotating component, the support ring forms a first blocking surface on the side facing the installation groove, the inner end of the installation groove forms an inner concave surface, and the steel ball is located between the first blocking surface and the inner concave surface.

[0013] It is further configured to include

[0014] A pump body, which is mounted on the tool body of the pipe expansion tool and connected to the sleeve body;

[0015] A piston rod is movably arranged on the pump body and a first spring is sleeved on its outer circumference;

[0016] A second spring, which is pressed between the rotating component and the pump body;

[0017] A working chamber is provided in the pump body, a piston is movably provided at the inner end of the working chamber, a fixing seat is fixed at the outer end, the inner end of the piston rod is fixed to the piston, and the outer end passes through the fixing seat to connect to the ejector pin, and the first spring is located between the piston and the fixing seat.

[0018] It is further configured that a limiting groove is provided on the circumferential surface of the piston rod along its length direction, a limiting ball is provided in the limiting groove; and a groove for accommodating the limiting ball is provided on the fixing seat.

[0019] It is further configured that a limit retaining ring is provided on the inner side of the fixed seat, and a second blocking surface is formed on the outer side of the limit retaining ring which can be blocked on the inner side of the limit ball; the inner end of the first spring is abutted against the outer end surface of the piston, and the outer end of the first spring extends into the limit retaining ring and abuts against the inner wall of the limit retaining ring.

[0020] It is further configured that a mounting cavity is provided in the sleeve, and the rotating component is located in the mounting cavity;

[0021] A first abutment platform is formed on the rotating component, a second abutment platform is formed inside the installation cavity, and the second abutment platform is blocked on the outer side of the first abutment platform.

[0022] It is further configured that the front end of the sleeve is connected to the tube expansion mold through a locking cap, an annular groove is provided on the inner side of the locking cap, the tube expansion mold includes a mold base, the thickness of the mold base is smaller than the width of the annular groove, and a tightening spring is provided on the circumferential surface of the mold base and between the annular groove.

[0023] An electric hydraulic pipe expansion tool comprises a tool body, one end of which is provided with a motor drive mechanism and an oil bag, and the other end is provided with the above-mentioned working component, and an oil passage is opened in the tool body to transfer the oil in the oil bag to the working component.

[0024] Compared with the prior art, the present invention has the following outstanding and beneficial technical effects:

[0025] 1. The present invention has a curved groove along the length direction of the ejector pin, and a positioning portion is arranged between the curved groove and the rotating component. When working, the ejector pin can not only promote the expansion of the mold, but also drive the rotating component to rotate, thereby driving the tube expansion mold to rotate at a certain angle, so that the tube mouth can be fully stressed during the process of expanding the tube mouth, thereby improving the expansion quality of the tube mouth; the present invention adopts the method of opening a curved groove to realize the rotation of the rotating component, has a simple structure, is easy to process, and has a good effect of driving the rotation.

[0026] 2. The positioning part of the present invention is a steel ball, and a mounting groove is provided on the inner side of the rotating part. One side of the steel ball is embedded in the mounting groove, and the other side of the steel ball is embedded in the curved groove. The rotating part is driven to rotate by the steel ball rolling along the curved groove. The steel ball is smooth and has small resistance, making it easier to drive the rotating part to rotate.

[0027] 3. The rotating component of the present invention is provided with a structure in which ratchet and pawl cooperate with each other between the driving block and the rotating block. The motion mechanism composed of the ratchet and pawl can realize the unidirectional rotation of the rotating component, driving the pipe expansion mold to always rotate in one direction, so that the internal expansion surface of the pipe can be more uniform.

[0028] 4. The present invention provides a spring with one end against one side of the pawl in the driving block. The spring is pressed between the driving block and the pawl to exert a certain pressure on the pawl, so that the pawl can be better clamped on the ratchet teeth.

[0029] 5. The present invention provides a limiting groove on the circumference of the piston rod along its length direction, a limiting ball is provided in the limiting groove, and a groove for accommodating the limiting ball is provided on the fixed seat. The setting of the limiting ball and the limiting groove has a limiting effect on the piston rod, preventing the piston rod from rotating with the rotating parts and the tube expansion mold, thereby enhancing the stability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a structural schematic diagram of the electric hydraulic pipe expanding tool of the present invention.

[0031] Figure 2 It is a simplified structural diagram of the working components of the present invention.

[0032] Figure 3 It is a structural schematic diagram of the connection structure between the rotating part of the working assembly and the ejector pin of the present invention.

[0033] Figure 4 It is a cross-sectional view of the working component of the present invention.

[0034] Figure 5 yes Figure 4 A partial enlarged view of point A.

[0035] Figure 6 yes Figure 4 A partial enlarged view of point B.

[0036] Figure 7 It is a cross-sectional view of the connection structure between the rotating part of the working assembly and the ejector pin of the present invention.

[0037] Figure markings: 1-pump body; 11-working chamber; 2-tool body; 3-piston rod; 31-thimble; 32-curved groove; 33-steel ball; 34-piston; 35-fixed seat; 351-groove; 36-limiting groove; 37-limiting ball; 38-limiting retaining ring; 381-second blocking surface; 41-first spring; 42-second spring; 43-tightening tension spring; 5-tube expansion mold; 51-mold base; 61-driving block; 611-installing groove; 612-inner concave surface; 62-rotating block; 63-ratchet ring; 631-ratchet; 64-pawl; 65-spring; 66-support ring; 661-first blocking surface; 71-fixing pin; 72-fixing pin; 8-sleeve; 81-installing chamber; 9-locking cap; 91-annular groove. DETAILED DESCRIPTION

[0038] The present invention will be further described below with reference to specific embodiments of the present invention. Figure 1-Figure 7 ,

[0039] An electrohydraulic pipe expansion tool, such as Figure 1As shown, it includes a tool body 2, one end of which is provided with a motor drive mechanism 21 and an oil bag 22, and the other end is provided with a working component. Oil passages are opened in the working component and the tool body. After power is turned on, the motor drive mechanism 21 starts to operate, pumps the oil in the oil bag 22 into the oil passage in the tool body, and gradually pushes the working component to work.

[0040] like Figure 1-3 As shown, the working assembly includes a pump body 1 mounted on a tool body 2, a piston rod 3 movably arranged on the pump body 1 and having a first spring 41 sleeved on the outer circumference, an ejector pin 31 fixed to the front end of the piston rod 3, and a tube expansion mold 5. The tube expansion mold 5 is connected to the ejector pin 31 through a rotating component. The circumference of the ejector pin 31 is provided with a curved groove 32 along its length direction. Figure 3 As shown, the curved groove 32 is arranged in a curved manner, the rotating component is sleeved on the outer side of the ejector pin 31 and is provided with a positioning portion at least part of which can be embedded in the curved groove 32 on the inner side. Since the curved groove 32 is arranged in a curved manner, the head end and the tail end of the curved groove 32 are not in a straight line. When the ejector pin 31 performs a forward and backward linear motion, the curved groove 32 moves forward or backward relative to the positioning portion and the rotating component, and the rotating component rotates relatively along the curved groove 32, that is, the linear motion of the ejector pin can be converted into a circumferential rotation of the rotating component.

[0041] A second spring 42 is provided between the rotating component and the pump body 1 , and the second spring 42 provides a supporting force for the rotating component to prevent the rotating component from moving backward when the ejector pin 31 is reset.

[0042] like Figure 3 As shown, a mounting groove 611 is provided inside the rotating component; the positioning part is a steel ball 33, one side of the steel ball 33 is embedded in the mounting groove 611, and the other side of the steel ball 33 is embedded in the curved groove 32. The rotating component includes a driving block 61 and a rotating block 62 sleeved on the outer periphery of the ejector pin 31, and the inner periphery of the driving block 61 is provided with a mounting groove 611 for accommodating the steel ball 33.

[0043] The first implementation of the mounting groove 611 is as follows: Figure 3 and Figure 5 As shown in FIG. , a countersunk hole is opened along the axial direction of the driving block 61 (i.e., the outer side and the lower side of the mounting groove 611 are both open designs). At this time, in order to ensure that the steel ball 33 always rolls only in the mounting groove (if the steel ball rolls out of the mounting groove, the rotating part cannot be driven to rotate, or the rotation effect is poor), an annular support ring 66 needs to be added to the inner side of the driving block 61, as shown in FIG. Figure 4 and Figure 5As shown, the support ring 66 forms a first blocking surface 661 on one side facing the mounting groove 611 , and an inner concave surface 612 is formed at the inner end of the mounting groove 611 . The steel ball 33 is located between the first blocking surface 661 and the inner concave surface 612 .

[0044] The second embodiment of the mounting groove 611 can be a countersunk hole opened along the radial direction of the driving block 61, that is, the mounting groove is opened toward one side of the curved groove 32, and the front and rear ends of the mounting groove 611 toward the axial direction of the driving block 61 are closed. At this time, since both ends are closed, the steel ball 33 can only roll in the mounting groove 611, so there is no need to set the support ring 66. Compared with the first embodiment, this method can save the support ring, but it needs to make a radial opening on the inner side of the driving block, and the processing technology is cumbersome.

[0045] like Figure 3 and Figure 7 As shown, the inner end of the rotating block 62 is provided with a ratchet ring 63 sleeved on the outer circumference of the driving block 61, and the outer end of the rotating block 62 is sleeved on the outer circumference of the ejector pin 31 and is used to connect the tube expansion mold 5. A plurality of ratchet teeth 631 are provided on the inner side of the ratchet ring 63, and a pawl 64 cooperating with the ratchet teeth 631 is provided on the driving block 61. A first mounting hole 613 is provided on the inner side of the driving block 61, and the pawl 64 is installed in the first mounting hole 613 through a fixing pin 72. A second mounting hole 614 is provided on the side wall of the first mounting hole 613 on the inner side of the driving block 61, and a spring 65 with one end against one side of the pawl 64 is provided in the second mounting hole 614.

[0046] The ratchet ring 63 and the rotating block 62 are arranged separately or integrally. Figure 3 As shown, when the ratchet ring 63 and the rotating block 62 are separately provided, the ratchet ring 63 is fixed to the rotating block 62 by a fixing pin 71 .

[0047] The working principle of the rotating part is as follows:

[0048] See also Figure 3 and Figure 7 When expanding the tube, the tube expanding mold 5 is inserted into the tube fitting, and the ejector pin 31 moves forward, gradually expanding the tube expanding mold 5 to achieve the purpose of expanding the tube fitting; the steel ball 33 gradually moves relatively from the original outer end of the curved groove 32 to the inner end of the curved groove 32. Since the head end and the end end of the curved groove 32 are not in a straight line, the driving block 61 will be prompted to rotate clockwise. At this time, since the tube expanding mold 5 is stretched and close to the inner wall of the tube fitting, it will be subject to resistance from the tube fitting, and the tube expanding mold and the rotating block will not rotate with the driving block 61; the ratchet 64 overcomes the elastic force of the spring 65 in this process, and produces relative sliding rotation with the ratchet 631.

[0049] When one tube expansion is completed and the ejector pin 31 moves backward to reset, the steel ball 33 gradually moves relatively from the inner end of the curved groove 32 to the outer end of the curved groove 32. Since the head and the end of the curved groove 32 are not in a straight line, the driving block 61 and the pawl 64 are prompted to rotate counterclockwise. The pawl 64 abuts against the ratchet teeth 631 of the ratchet ring 63. At this time, the tube expansion mold 5 is gradually closing and separating from the inner wall of the pipe fitting, and the resistance of the pipe fitting is reduced. Driven by the driving block 61 and the pawl 64, the ratchet ring 63 and the rotating block 62 also drive the tube expansion mold 5 to rotate counterclockwise.

[0050] The above process is repeated, and the driving block 61 keeps rotating repeatedly clockwise and counterclockwise during the forward and backward movement of the ejector pin 31; and the ratchet ring 63, the rotating block 62 and the tube expansion mold 5 only rotate counterclockwise following the driving block 61 during the backward movement and resetting process of the ejector pin 31, thereby ensuring the unidirectional rotation of the tube expansion mold and promoting more uniform tube expansion.

[0051] like Figure 4 and Figure 6 As shown, a working chamber 11 is provided in the pump body 1, a piston 34 is movably provided at the inner end of the working chamber 11, and a fixing seat 35 is fixed at the outer end, the inner end of the piston rod 3 is fixed to the piston 34, and the outer end passes through the fixing seat 35 to connect the ejector pin 31, and the first spring 41 is located between the piston 34 and the fixing seat 35. The inner end of the working chamber 11 is connected to the oil passage, and the oil can push the piston to drive the piston rod and the ejector pin to move forward, and the first spring 41 is used to reset the piston rod.

[0052] Since the ejector pin is directly fixedly connected to the piston rod, in order to prevent the piston rod from being rotated by the rotating parts, a limiting groove 36 is provided on the circumference of the piston rod 3 along its length direction, and a limiting ball 37 is provided in the limiting groove 36; a groove 351 for accommodating the limiting ball 37 is provided on the fixing seat 35. In order to ensure that the limiting ball 37 rolls only in the groove 351, the groove 351 is provided in the same manner as the above-mentioned installation groove 611. When the groove 351 is a groove with openings on the front side and the bottom side, as shown in FIG. Figure 4 and Figure 6 As shown, a stop ring 38 needs to be arranged inside the fixing seat 35, and a second blocking surface 381 is formed outside the stop ring 38, which can be blocked inside the stop ball 37; the inner end of the first spring 41 is against the outer end surface of the piston 34, and the outer end of the first spring 41 extends into the stop ring 38 and is against the inner wall of the stop ring 38. When the groove 351 is a countersunk hole with only a bottom opening, the blocking structure of the stop ring 38 can be eliminated.

[0053] like Figure 1 and Figure 4As shown, a sleeve 8 is threadedly connected to one side of the pump body 1, and a mounting cavity 81 is provided in the sleeve 8. The rotating component and the second spring 42 are located in the mounting cavity 81. A first abutment platform 621 is formed on the rotating component (the first abutment platform 621 is formed on the rotating block 62 in this embodiment), and a second abutment platform 82 is formed in the mounting cavity 81. The second abutment platform 82 is blocked on the outside of the first abutment platform 621 to prevent the rotating component from following the ejector pin to move outward and affect its rotation. A support ring 66 is provided at the inner end of the rotating component, and the second spring 42 is abutted between the end face of the pump body 1 and the support ring 66. The second spring 42 provides a supporting force for the rotating component to prevent the ejector pin 31 from moving backward with the rotating component when the ejector pin 31 is reset (when a structure without a support ring 66 is adopted, the second spring 42 is directly abutted on the inner end face of the driving block 61).

[0054] The front end of the sleeve 8 is connected to the tube expansion mold 5 through a locking cap 9, and the locking cap 9 is threadedly connected to the sleeve 8. An annular groove 91 is provided on the inner side of the locking cap 9. The tube expansion mold 5 includes a mold base 51. The thickness of the mold base 51 is smaller than the width of the annular groove 91, and a tightening tension spring 43 is provided on the circumferential surface of the mold base 51 and between the annular groove 91, so that the mold base 51 of the tube expansion mold 5 can rotate in the annular groove 91 and expand outward to achieve the expansion effect on the pipe fitting.

[0055] Working principle of the present invention:

[0056] The tube expansion mold 5 of the present invention is composed of a plurality of cone claws 52. When the piston 34 is pushed by the oil, the piston rod 3 and the ejector pin 31 are driven to move forward. During the forward movement of the ejector pin, the cone claws 52 are gradually opened, thereby expanding the inner hole of the pipe fitting. Since a curved groove 32 is provided on the outer periphery of the ejector pin 31, and a steel ball 33 is provided in the rotating component, the forward linear motion of the ejector pin is converted into the rotation of the rotating component under the interaction of the steel ball and the curved groove, thereby driving the tube expansion mold 5 to rotate when the ejector pin 31 moves backward and resets (for the specific rotation principle, please refer to the "working principle of the rotating component" mentioned above).

[0057] After the ejector pin is reset, it continues to be pushed forward by the oil to expand the pipe fitting. After multiple reciprocating movements, the expansion and rotation of the pipe expansion mold 5 can make the inner circle of the pipe fitting evenly stressed, making the expanded connection hole closer to a perfect circle, making it easier to connect the pipes and enhancing the tightness of the pipe connection.

[0058] In addition, since the limiting groove 36 and the limiting ball 37 are provided on the piston rod 3, the piston rod 3 can only perform linear motion and will not rotate due to the influence of the rotating parts, so that the structure of the piston rod and the ejector movement is more stable.

[0059] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A working assembly of a pipe expansion tool, characterized in that: include: A sleeve body (8); A tube expansion die (5) is arranged at the front end of the sleeve (8); an ejector pin (31) is inserted through the middle of the sleeve (8); the front end of the ejector pin (31) can extend into the tube expansion die (5), so that the tube expansion die (5) is opened for operation; A curved groove (32) is formed on the peripheral surface of the ejector pin (31) along its length direction, and the beginning and the end of the curved groove (32) are not in a straight line; A rotating component is provided inside the sleeve (8), a positioning portion is provided inside the rotating component, and at least part of the positioning portion is embedded in the curved groove (32), so that the linear motion of the ejector pin is converted into circumferential rotation of the rotating component; The front end of the rotating component is connected to the tube expansion mold and drives it to rotate; The rotating component comprises: a driving block (61) which is sleeved on the outer circumference of the ejector pin (31) and is provided with a mounting groove (611); a rotating block (62) having one end provided with a ratchet ring (63) sleeved on the outer circumference of the driving block (61), and the other end sleeved on the outer circumference of the ejector pin (31) and connected to the tube expansion mold (5); a plurality of ratchet teeth (631) are provided on the inner side of the ratchet ring (63), and a ratchet pawl (64) which cooperates with the ratchet teeth (631) is provided on the driving block (61); a spring (65) is provided in the driving block (61) and one end of the spring abuts against one side of the ratchet pawl (64); One side of the positioning portion is embedded in the installation groove (611), and the other side is embedded in the curved groove (32).

2. The working assembly of the pipe expansion tool according to claim 1, characterized in that: The positioning portion is a steel ball (33).

3. The working assembly of the pipe expansion tool according to claim 1, characterized in that: The ratchet ring (63) and the rotating block (62) are arranged separately or integrally. When arranged separately, the ratchet ring (63) is fixed to the rotating block (62) via a fixing pin (71).

4. The working assembly of the pipe expansion tool according to claim 2, characterized in that: A support ring (66) is provided on the inner side of the rotating component, and a first blocking surface (661) is formed on the side of the support ring (66) facing the mounting groove (611). An inner concave surface (612) is formed at the inner end of the mounting groove (611), and the steel ball (33) is located between the first blocking surface (661) and the concave surface (612).

5. The working assembly of the pipe expansion tool according to any one of claims 1 to 3, characterized in that: Also includes: A pump body (1) is mounted on a tool body (2) of the pipe expansion tool and is connected to the sleeve body (8); A piston rod (3) which is movably arranged on the pump body (1) and has a first spring (41) sleeved on its outer circumference; a second spring (42) which is pressed between the rotating component and the pump body (1); The pump body (1) is provided with a working chamber (11), the inner end of the working chamber (11) is movably provided with a piston (34), and the outer end is fixedly provided with a fixing seat (35), the inner end of the piston rod (3) is fixed to the piston (34), and the outer end passes through the fixing seat (35) to connect with the ejector pin (31), and the first spring (41) is located between the piston (34) and the fixing seat (35).

6. The working assembly of the pipe expansion tool according to claim 5, characterized in that: A limiting groove (36) is provided on the circumferential surface of the piston rod (3) along its length direction, and a limiting ball (37) is arranged in the limiting groove (36); and a groove (351) for accommodating the limiting ball (37) is provided on the fixing seat (35).

7. The working assembly of the pipe expansion tool according to claim 6, characterized in that: A limit retaining ring (38) is provided on the inner side of the fixing seat (35), and a second retaining surface (381) capable of being retained on the inner side of the limit retaining ring (38) is formed on the outer side of the limit retaining ring (38); the inner end of the first spring (41) is abutted against the outer end surface of the piston (34), and the outer end of the first spring (41) extends into the limit retaining ring (38) and abuts against the inner wall of the limit retaining ring (38).

8. The working assembly of the pipe expansion tool according to any one of claims 1 to 3, characterized in that: The sleeve body (8) is provided with a mounting cavity (81), and the rotating component is located in the mounting cavity (81); A first abutment platform (621) is formed on the rotating component, a second abutment platform (82) is formed inside the installation cavity (81), and the second abutment platform (82) is arranged outside the first abutment platform (621).

9. An electric hydraulic pipe expansion tool, comprising a tool body (2), characterized in that: The tool body (2) is provided with a motor drive mechanism (21) and an oil bag (22) at one end, and with a working component according to any one of claims 1 to 8 at the other end. An oil passage is provided in the tool body (2) for transferring the oil in the oil bag to the working component.

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