An electric pipe expander

Abstract

The utility model relates to electric tool technical field especially relates to a kind of electric pipe expander, including shell, chuck body, eccentric shaft being axially moved in shell and the eccentric head being set on eccentric shaft.This structure also includes drive motor, shaft coupling, fixed nut, screw thread and elastic member;The drive motor is fixed in shell, and its output end is connected with shaft coupling transmission;The fixed nut is fixedly arranged in shell, and screw thread and fixed nut are threadedly matched;Screw thread, shaft coupling and eccentric shaft are coaxially nested from outside to inside in order, and eccentric shaft and screw thread, eccentric shaft and shaft coupling are circumferentially fixed, axially slidably connected;Screw thread is provided with the elastic cavity in the axial direction, and elastic member is accommodated therein and two ends are respectively applied on screw thread and eccentric shaft.This structure abandons complex worm gear and other multistage transmission structure, transmission chain is short, compact structure, transmission is efficient.

Description

Technical Field

[0001] This utility model relates to the field of power tool technology, and in particular to an electric pipe expander. Background Technology

[0002] In fields such as pipeline construction, pipe expanders are frequently used to widen the ends of metal pipes into flared openings for connection. Traditional pipe expanders are mostly manual tools, relying on manual rotation of a screw to advance an eccentric head, resulting in high labor intensity and low efficiency. Therefore, electric pipe expanders have emerged on the market.

[0003] Existing electric pipe expanders mostly use a worm gear mechanism as the core of their transmission. A motor drives the worm to rotate, which in turn drives the meshing worm gear. The worm gear then drives the internal mandrel and eccentric head to rotate and move forward simultaneously, completing the pipe expanding operation, via a key or other structure. While achieving electrification, this transmission scheme has significant drawbacks: First, its "worm-worm gear-key-mandrel" transmission path involves multiple power conversions, resulting in a large number of components and a complex overall structure. Furthermore, the worm gear itself has a large pitch circle diameter, leading to a bulky transmission component and a heavy tool head, affecting operational flexibility in confined spaces. Second, the lengthy transmission chain results in increased mechanical friction and energy loss, leading to relatively low transmission efficiency. Finally, the complex structure also increases assembly difficulty and the risk of malfunction. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the above-mentioned problems and provide an electric pipe expander with a compact structure and high transmission efficiency.

[0005] The technical solution of this utility model is: an electric pipe expander, comprising a housing, a clamp body, an eccentric shaft axially movable within the housing, and an eccentric head disposed on the eccentric shaft for cooperating with the clamp body to expand the pipe, characterized in that: It also includes drive motors, couplings, fixing nuts, threaded sleeves, and elastic components; The drive motor is fixed inside the housing, and its output end is connected to the coupling for transmission. The fixing nut is fixedly installed inside the housing, and the threaded sleeve is threadedly engaged with the fixing nut; The threaded sleeve, the coupling, and the eccentric shaft are coaxially sleeved from the outside to the inside, and the eccentric shaft and the threaded sleeve, as well as the eccentric shaft and the coupling, are connected in a circumferentially fixed and axially sliding manner; the threaded sleeve has an axial elastic cavity, the elastic element is housed in the elastic cavity, and its two ends act on the threaded sleeve and the eccentric shaft respectively.

[0006] This solution constitutes a unique integrated "rotation-propulsion-buffering" working system. The drive motor synchronously transmits power to the threaded feed sleeve and eccentric shaft via a coupling, driving them to rotate synchronously. Simultaneously, the rotating threaded feed sleeve generates axial feed under the action of a fixed nut. This feed force is indirectly and flexibly transmitted to the eccentric shaft through an elastic element, ultimately driving the eccentric head to perform the tube expansion operation. The outstanding advantage of this design is that it achieves the three key functions of complex rotary motion conversion, linear feed, and pressure buffering in a simple and efficient manner through a highly coordinated mechanical structure. This not only fundamentally avoids the structural complexity and energy loss of traditional multi-stage transmissions, but also achieves process self-adaptation and overload protection through built-in elastic elements, enabling the tool to possess high efficiency, high reliability, and high forming quality.

[0007] Preferably, the drive motor is a geared motor, which ensures that a large torque that meets the requirements of tube expansion can be output within a compact space, thus guaranteeing the power performance of the tool.

[0008] Furthermore, the drive motor is a right-angle geared motor, the housing has a U-shaped structure, the axial direction of the drive motor body is perpendicular to the axial direction of the coupling, and the two are respectively arranged on adjacent sides of the U-shaped structure. The cooperation between the right-angle geared motor and the U-shaped housing realizes efficient conversion of power direction and compact layout of the overall structure, significantly improving the tool's maneuverability and ease of operation in confined spaces.

[0009] Preferably, the elastic element is a helical spring, with its two ends abutting against the bottom wall of the elastic cavity of the threaded sleeve and the end face of the eccentric shaft facing the elastic cavity, respectively. The helical spring has linear, stable, and durable force-displacement characteristics, providing predictable and lasting flexible pressure for the tube expansion process, effectively ensuring the stability of the molding quality.

[0010] Preferably, the threaded sleeve has a first axial groove, the coupling has a second axial groove, and the eccentric shaft has a protruding limiting pin, which is simultaneously slidably disposed within both the first and second grooves. This synergistic design of the limiting pin and the double grooves is key to achieving decoupling of power transmission and axial buffering. The structure is simple, with few parts, ensuring lossless torque transmission while providing precise guidance for the independent axial movement of each component, resulting in smooth and reliable operation.

[0011] Furthermore, the eccentric shaft is provided with a pin hole, and the limiting pin is fixedly inserted into the pin hole. This structure, which involves separate machining and reassembly of the limiting pin and the pin hole, reduces the machining difficulty and manufacturing cost of the eccentric shaft itself. It also facilitates the individual selection and replacement of easily worn limiting pins, improving the maintainability and economy of the parts.

[0012] Preferably, the eccentric head is rotatably connected to one end of the eccentric shaft via a bearing.

[0013] Preferably, the housing comprises a first housing and a second housing that are joined together. The modular housing design significantly simplifies the assembly process of the internal structure and subsequent maintenance.

[0014] Preferably, the outer side of the housing is provided with a battery pack mounting base, which realizes the integration and portability of the power source.

[0015] The beneficial effects of this utility model are: 1. This utility model eliminates the complex multi-stage transmission structure of worm gears, flat keys, and transmission nuts. It directly and synchronously transmits the rotational power to the threaded screw sleeve and eccentric shaft through a coupling. The rotational motion is converted into axial feed of the threaded screw sleeve by the threaded pair formed by the threaded screw sleeve and the fixed nut. Finally, the feed force is transmitted through the elastic element, realizing the integration of transmission, feed and buffer functions. The transmission chain is short, the structure is compact and the number of parts is small. This not only reduces the manufacturing cost and assembly difficulty, but also significantly improves the transmission efficiency and reliability.

[0016] 2. This utility model achieves automatic switching from rigid propulsion to flexible pressure through a built-in elastic element. When the tube expansion resistance increases, the elastic element is compressed, which can effectively prevent tube damage, ensure full flaring of the tube opening, avoid rigid locking of the system, protect the motor from stalling and burning out, and significantly improve the reliability of the tool and the quality of tube expansion.

[0017] 3. This utility model achieves simultaneous circumferential linkage of the three components through the cooperation of a single limiting pin, a threaded screw-in sleeve, and a sliding groove on the coupling, with a simple structure. It also allows the axial feed of the threaded screw-in sleeve and the buffered movement of the eccentric shaft to proceed without interference, cleverly decoupling power transmission from axial displacement. This design boasts high integration and reliable operation. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0019] Figure 2 This is a schematic diagram of the structure of this utility model after the first shell has been removed.

[0020] Figure 3 This is a cross-sectional view of the present invention.

[0021] Figure 4 This is an exploded view of a partial structure of the present invention. Detailed Implementation

[0022] See Figures 1-4The electric pipe expander provided in this embodiment includes a housing 1, a clamp body 2, an eccentric shaft 3, an eccentric head 4, a fixing nut 5, a threaded screw sleeve 6, a coupling 7, a helical spring 8, a drive motor 9, and a limit pin 10.

[0023] The housing 1 is a U-shaped structure that is detachably assembled from a first housing and a second housing by screws. Its outer side is provided with a battery pack mounting base 11 for installing a rechargeable battery pack, providing portable power for the entire tool.

[0024] The drive motor 9 serves as the power source in this embodiment, and is preferably a right-angle geared motor. The output shaft of the drive motor 9 is directly connected to the coupling 7 to drive its rotation. The axial direction of the drive motor 9 is perpendicular to the axial direction of the coupling 7, and the two are respectively arranged on adjacent sides of the U-shaped structure of the housing 1. The fixing nut 5 is fixedly installed inside the housing 1, and the threaded sleeve 6 is fitted into the inner hole of the fixing nut 5. The two are engaged by threads (not shown in the figure).

[0025] The threaded sleeve 6, the coupling 7, and the eccentric shaft 3 are coaxially sleeved from the outside to the inside, and the eccentric shaft 3 and the threaded sleeve 6, as well as the eccentric shaft 3 and the coupling 7, are connected in a circumferentially fixed and axially sliding manner.

[0026] Specifically, this embodiment achieves the above connection through a limiting pin 10 structure: a U-shaped first groove 62 is provided at one axial end of the threaded sleeve 6, and a U-shaped second groove 71 is provided at the other axial end of the coupling 7. The U-shaped openings of the first groove 62 and the second groove 71 are in opposite directions. A radial pin hole is machined on the eccentric shaft 3, and the limiting pin 10 is pressed into and fixed in the pin hole, thus protruding from the eccentric shaft 3. The limiting pin 10 passes through and slides within both the first groove 62 and the second groove 71. In this way, when the motor 9 drives the coupling 7 to rotate, the torque is synchronously transmitted to the threaded sleeve 6 and the eccentric shaft 3 through the limiting pin 10. Since the threaded sleeve 6 engages with the fixing nut 5, it will move axially while rotating, advancing towards the chuck body 2.

[0027] An axial elastic cavity 61 is recessed at the end of the threaded sleeve 6 facing the chuck body 2. The helical spring 8 is housed within this elastic cavity 61. One end of the helical spring 8 directly abuts against the bottom wall of the elastic cavity 61, and the other end directly abuts against the end face of the eccentric shaft 3 facing the elastic cavity 61. When the threaded sleeve 6 moves forward, it pushes the eccentric shaft 3 forward along with it via the helical spring 8. The eccentric head 4 is rotatably connected to the front end of the eccentric shaft 3 via a bearing. At the end of the pipe expansion operation, when the eccentric head 4 and the chuck body 2 completely tighten the pipe fitting and the resistance increases sharply, the motor 9 still drives the threaded sleeve 6 to rotate forward. At this time, the helical spring 8 is compressed, thereby absorbing the overload axial force. This avoids transmission mechanism jamming and motor stalling, and ensures that the eccentric head 4 can continue to rotate under constant pressure, completing the final plastic forming of the pipe end, significantly improving the quality of pipe expansion.

[0028] Working process: The drive motor 9 starts, driving the threaded insert sleeve 6 and eccentric shaft 3 to rotate synchronously via coupling 7. The rotating threaded insert sleeve 6, constrained by the fixing nut 5, advances forward, pushing the eccentric shaft 3 and eccentric head 4 to rotate and move forward simultaneously via the helical spring 8. The eccentric head 4 gradually squeezes into the pipe end within the clamp body 2, beginning pipe expansion. When the expansion force reaches its peak, the helical spring 8 is compressed, acting as a buffer. The feed force of the threaded insert sleeve 6 is converted into the spring force, acting continuously and stably on the pipe. Simultaneously, the eccentric head 4 continues to rotate, rolling the pipe end into a smooth, uniform flared opening, completing high-quality pipe expansion. After the operation is completed, the motor 9 reverses, the entire transmission chain moves in the opposite direction, the threaded insert sleeve 6 retracts, and under the action of the spring's restoring force, the eccentric shaft 3 and eccentric head 4 also return to their original positions, awaiting the next operation.

[0029] The specific embodiments described herein are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model are still covered by the claims of this utility model.

Claims

1. An electric pipe expander, comprising a housing, a clamping body, an eccentric shaft axially movable within the housing, and an eccentric head disposed on the eccentric shaft for cooperating with the clamping body to expand a pipe fitting, characterized in that: It also includes drive motors, couplings, fixing nuts, threaded sleeves, and elastic components; The drive motor is fixed inside the housing, and its output end is connected to the coupling for transmission. The fixing nut is fixedly installed inside the housing, and the threaded sleeve is threadedly engaged with the fixing nut; The threaded sleeve, the coupling, and the eccentric shaft are coaxially sleeved from the outside to the inside, and the eccentric shaft and the threaded sleeve, as well as the eccentric shaft and the coupling, are connected in a circumferentially fixed and axially sliding manner; the threaded sleeve has an axial elastic cavity, the elastic element is housed in the elastic cavity, and its two ends act on the threaded sleeve and the eccentric shaft respectively.

2. The electric pipe expander according to claim 1, characterized in that: The drive motor is a geared motor.

3. The electric pipe expander according to claim 2, characterized in that: The drive motor is a right-angle geared motor, the housing has a U-shaped structure, the axial direction of the drive motor body is perpendicular to the axial direction of the coupling, and the two are respectively arranged on adjacent sides of the U-shaped structure.

4. The electric pipe expander according to claim 1, characterized in that: The elastic element is a helical spring, with its two ends abutting against the bottom wall of the elastic cavity of the threaded sleeve and the end face of the eccentric shaft facing the elastic cavity, respectively.

5. The electric pipe expander according to claim 1, characterized in that: The threaded sleeve has a first groove along the axial direction, the coupling has a second groove along the axial direction, and the eccentric shaft has a limiting pin protruding from it. The limiting pin is simultaneously slidably disposed in the first groove and the second groove.

6. The electric tube expander according to claim 5, characterized in that: The eccentric shaft is provided with a pin hole, and the limiting pin is fixedly inserted into the pin hole.

7. The electric pipe expander according to claim 1, characterized in that: The eccentric head is rotatably connected to one end of the eccentric shaft via a bearing.

8. The electric pipe expander according to claim 1, characterized in that: The housing comprises a first housing and a second housing that are joined together.

9. The electric pipe expander according to claim 1, characterized in that: A battery pack mounting bracket is provided on the outside of the housing.

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