TUBE EXPANDER

20260061477 · 2026-03-05

Assignee

Zhejiang Prulde Electric Appliance Co., Ltd. (Jinhua, CN)

Inventors

Cpc classification

International classification

Abstract

Disposed is a tube expander, which relates to a power tool, including an expansion die, an ejector pin, a drive element, and an indexing assembly, the expansion die including jaws, the indexing assembly including a rotary member rotatably disposed, an energy storage member connected to the rotary member, and an indexing member driving the jaws to rotate, the indexing member being disposed between the rotary member and the jaws and operable to transmit an intermittent rotational action, the rotary member and the indexing member being operable to drivingly engage or drivingly disengage with respect to each other; the ejector pin moving forward drives the rotary member to rotate forward, the rotary member rotating forward drives the energy storage member to be elastically deformed for the latter to accumulate energy, the rotary member rotating forward being drivingly disengaged from the indexing member; the energy storage member recovers from the elastic deformation during rearward movement of the ejector pin driving the rotary member to rotate reversely, the rotary member rotating reversely being drivingly engaged with the indexing member to push the jaws to rotate. The load of the electric motor does not increase instantaneously when the jaws stall, i.e., the driving load the electric motor is stable, which helps ensure operational stability of the electric motor.

Claims

1. A tube expander, comprising: an expansion die comprising a plurality of jaws which are distributed circumferentially and operable to close and separate; an ejector pin movable in an anteroposterior direction, wherein the ejector pin moving forward forces the jaws to separate, and the ejector pin moving rearward releases the jaws so that the jaws close; a drive element configurable to drive the ejector pin to move; and an indexing assembly configurable to drive the separated jaws to rotate; wherein the indexing assembly comprises a rotary member configured to be rotatable, an energy storage member connected to the rotary member, and an indexing member configured to drive the jaws to rotate, the indexing member being disposed between the rotary member and the jaws and configured to transmit an intermittent rotational action, the rotary member and the indexing member being operable to drivingly engage or drivingly disengage with respect to each other; the ejector pin moving forward drives the rotary member to rotate forward, the rotary member rotating forward drives the energy storage member to be elastically deformed to accumulate energy, and the rotary member rotating forward is drivingly disengaged from the indexing member; and while the ejector pin is moving rearward, the energy storage member recovers from elastic deformation driving the rotary member to rotate reversely, the rotary member rotating reversely being drivingly engaged with the indexing member to push the jaws to rotate.

2. The tube expander according to claim 1, wherein the rotary member is sleeved on an outer periphery of the ejector pin, one of an outer circumferential wall of the ejector pin and an inner circumferential wall of the rotary member being provided with an interlocking groove, the other one thereof being provided with an interlocking block, at least a local portion of groove wall of the interlocking groove being twisted or inclined relative to a central axis of the ejector pin, the interlocking block being inserted in the interlocking groove, and the ejector pin moving forward drives, via fit between the interlocking groove and the interlocking block, the rotary member to rotate forward.

3. The tube expander according to claim 1, wherein the tube expander comprises a supporting sleeve which is fixedly arranged, the indexing member being rotatably disposed inside or outside the supporting sleeve, one end of the energy storage member being connected to the rotary member, an opposite end thereof being connected to the supporting sleeve.

4. The tube expander according to claim 3, wherein the rotary member is provided with a locating block, one end of the energy storage member being provided with a first connecting pin in hook connection with the locating block; and/or, the supporting sleeve is provided with a securing block, the opposite end of the energy storage member being provided with a second connection pin in hook connection with the securing block.

5. The tube expander according to claim 3, wherein one of the rotary member and the supporting sleeve is provided with a limiting block, and the other one thereof is provided with a limiting groove extending circumferentially, the limiting block being inserted in the limiting groove to limit a rotating angle of the rotary member.

6. The tube expander according to claim 1, wherein the energy storage member is disposed on an outer periphery of the rotary member, and the energy storage member is limited in the anteroposterior direction.

7. The tube expander according to claim 1, wherein the indexing member is sleeved on an outer periphery of the ejector pin, a convex tooth is provided on an inner circumferential wall of the indexing member, and a swingable ratchet is provided on the rotary member; wherein when the rotary member rotates forward, the ratchet slips relative to the convex tooth disposing the rotary member and the indexing member to be in a drivingly disengaged state, and when the rotary member rotates reversely, the ratchet abuts against the convex tooth disposing the rotary member and the indexing member to be in a drivingly engaged state.

8. The tube expander according to claim 7, wherein the indexing member is provided with an elastic member, one end of the elastic member being positionally retained, an opposite end thereof being in contact with the ratchet, the elastic member biasing the ratchet toward the convex tooth.

9. The tube expander according to claim 7, wherein the ratchet is provided on a front side of the indexing member, and the convex tooth is provided on an inner circumferential wall of a rear end of the indexing member.

10. The tube expander according to claim 1, wherein the tube expander further comprises a connecting sleeve which is fixedly arranged, the connecting sleeve being located outside the indexing member; and the expansion die further comprises an annular seat, rear ends of the respective jaws being connected to the annular seat, the expansion die being connected to the connecting sleeve via the annular seat so that the jaws mesh with the indexing member.

11. The tube expander according to claim 1, wherein the ejector pin has a cycle of movement; the tube expander is provided with a control panel, a detector, and a switch; the detector is electrically connected to the control panel and configured to directly or indirectly detect a position of the ejector pin; the switch is electrically connected to the control panel and configured to start/stop the cycle of movement; and in a case that the switch's state has changed before a predetermined node of the cycle of movement, the control panel commands, at the predetermined node, the drive element to stop driving the ejector pin.

12. The tube expander according to claim 11, wherein the tube expander is provided with a trigger maintaining synchronization with the ejector pin; and at the predetermined node of the cycle of movement, the trigger triggers the detector to detect a position of the ejector pin.

13. The tube expander according to claim 11, wherein the tube expander is provided with a manipulator arranged in correspondence with the switch; the switch enters an on state when the manipulator is pressed and enters an off state when the manipulator is released; if the switch switches from the on state to the off state before the predetermined node of the cycle of movement, the control panel commands, at the predetermined node, the drive element to stop driving the ejector pin; and/or, the cycle of movement of the ejector pin has an initial position corresponding to the closed jaws, and the predetermined node of the cycle of movement is the initial position of the ejector pin.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] FIG. 1 is an overall structural view of a tube expander according to a first implementation;

[0032] FIG. 2 is an internal structural view of the tube expander according to the first implementation;

[0033] FIG. 3 is a local internal structural view of the tube expander according to the first implementation;

[0034] FIG. 4 is a structure view of an expansion die in the tube expander according to the first implementation;

[0035] FIG. 5 is an axial sectional view of the expansion die in the tube expander according to the first implementation;

[0036] FIG. 6 is an exploded view of a transmission structure, an ejector pin, an indexing assembly, a supporting sleeve, and a connecting sleeve in the tube expander according to the first implementation;

[0037] FIG. 7 is a structural schematic diagram of a cam in the tube expander according to the first implementation;

[0038] FIG. 8 is a structural view of fit between a rotary member, an energy storage member, and the supporting sleeve in the tube expander according to the first implementation;

[0039] FIG. 9 is a structural view of the rotary member in the tube expander according to the first implementation;

[0040] FIG. 10 is a structural view of the rotary member in the tube expander from another perspective according to the first implementation;

[0041] FIG. 11 is an axial sectional view of the rotary member in the tube expander according to the first implementation;

[0042] FIG. 12 is a structural view of the energy storage member in the rotary member of the tube expander according to the first implementation;

[0043] FIG. 13 is a structural view of the supporting sleeve of the tube expander according to the first implementation;

[0044] FIG. 14 is a structural view of a rachet, an elastic member, and an indexing member in the tube expander according to the first implementation;

[0045] FIG. 15 is a structural view of the rachet in the tube expander according to the first implementation;

[0046] FIG. 16 is a structural view of the indexing member in the tube expander according to the first implementation;

[0047] FIG. 17 is an axial sectional view of the tube expander when the ejector pin is disposed at an initial position and the respective jaws are in a closed state according to the first implementation;

[0048] FIG. 18 is an axial sectional view of the tube expander when the ejector pin is disposed at an ejected position and the respective jaws are in a separated state according to the first implementation;

[0049] FIG. 19 is an overall structural view of a tube expander according to a second implementation;

[0050] FIG. 20 is an internal structural view of the tube expander according to the second implementation;

[0051] FIG. 21 is a local internal structural view of the tube expander according to the second implementation.

[0052] In the drawings: 100expansion die; 110jaw; 111arcshaped flange; 112second engaging block; 120annular seat; 121annular recess; 130closing spring; [0053] 200ejector pin; 210ejection rod; 211rod body; 212rear plate; 213lug; 220tapered head; 230roller; 240pin rod; 250pin stud; [0054] 300drive element; 310electric motor; 320reduction gear mechanism; [0055] 400indexing assembly; 410rotary member; 411central bore; 412locating block; 413recessed region; 414locating groove; 420energy storage member; 420atension spring; 421first connecting pin; 422second connecting pin; 430indexing member; 431first engaging block; 441interlocking groove; 441afirst groove wall; 441bsecond groove wall; 442interlocking block; 451limiting block; 452limiting groove; 461convex tooth; 462rachet; 463pin; 464elastic member; 464acompression spring; 465protrusion; 470baffle plate; 480engaging structure; [0056] 500transmission structure; 510rotary shaft; 520cam; 521push surface; 522avoidance surface; 523transition surface; [0057] 600housing; 610handle; [0058] 710reset spring; 720supporting sleeve; 721flange; 722extended portion; 723sliding groove; 724securing block; 725boss; 730connecting sleeve; [0059] 810control panel; 820switch; 830detector; 840trigger; 850manipulator.

DETAILED DESCRIPTION OF EMBODIMENTS

[0060] Hereinafter, the present disclosure will be further illustrated through example implementations with reference to the accompanying drawings. It would be understood that the orientational or positional relationships indicated by the terms upper, lower, left, right, longitudinal, transverse, inner, outer, vertical, horizontal, top, bottom, and etc. are orientational and positional relationships based on the drawings, which are intended only for facilitating description of the disclosure and simplifying relevant illustrations, not for indicating or implying that the devices or elements compulsorily possess those specific orientations and are compulsorily configured and operated with those specific orientations; therefore, such terms shall not be construed as limitations to the disclosure.

First Implementation

[0061] FIGS. 1 to 18 illustrate a tube expander 10 according to a first implementation of the present disclosure, comprising: [0062] an expansion die 100 comprising a plurality of jaws 110 distributed circumferentially and operable to close and separate; [0063] an ejector pin 200 movable in an anteroposterior direction, the ejector pin 200 moving forward to force the jaws 110 to separate, the ejector pin 200 moving rearward so that the jaws 110 close; [0064] a drive element 300 configurable to drive the ejector pin 200 to move; [0065] and an indexing assembly 400 configurable to drive the separated jaws 110 to rotate; [0066] the indexing assembly 400 comprises a rotary member 410 configured to be rotatable, an energy storage member 420 connected to the rotary member 410, and an indexing member 430 operable to drive the jaws 110 to rotate, the indexing member 430 being disposed between the rotary member 410 and the jaws 110 and configured to transmit an intermittent rotational action, the rotary member 410 and the indexing member 430 being drivingly engaged or drivingly disengaged; [0067] the ejector pin 200 moving forward drives the rotary member 410 to rotate forward, the rotary member 410 rotating forward drives the energy storage member 420 to be elastically deformed so that the energy storage member 420 accumulates energy, and the rotary member 410 rotating forward is drivingly disengaged from the indexing member 430; [0068] and the energy storage member 420 recovers from elastic deformation driving the rotary member 410 to rotate reversely while the ejector pin 200 is moving rearward, the rotary member 410 rotating reversely being drivingly engaged with the indexing member 430 to push the jaws 110 to rotate.

[0069] Since the rotating action of the jaws 110 occurs during rearward movement and reset process of the ejector pin 200, no additional wait time needs to be set for the tube expander 10 for the jaws 110 to complete the rotating action, whereby work efficiency of the tube expander 10 can be enhanced. Additionally, since rotation of the jaws 110 is driven by the indexing member 430 drivingly engaged with the rotary member 410 and reverse rotation of the indexing member 430 is driven by the energy storage member 420 recovering from the elastic deformation, the action force driving the jaws 110 to rotate is not directly originated from an electric motor 310, so that upon stalling of the jaws 110, the driving load of the electric motor 310 does not increase instantaneously, i.e., the electric motor 310 is contributed with a stable driving load, which ensures operational stability of the electric motor 310.

[0070] In this implementation, the direction in which the ejector pin 200 moves toward the expansion die 100 to drive the respective jaws 110 to separate is defined as anterior (front), and the direction in which the ejector pin 200 moves away from the expansion die 100 to drive the rejective jaws to close is defined as posterior (rear).

[0071] Referring to FIGS. 4 and 5, in this implementation, the expansion die 100 further comprises an annular seat 120, rear ends of the respective jaws 110 being connected to the annular seat 120. Specifically, six jaws 110 are provided, the six jaws 110 being arranged in tandem into a circle along the circumferential direction of the annular seat 120. A circle of annular recess 121 is formed on an inner wall of a front end of the annular seat 120, rear ends of the respective jaws 110 projecting into the front end of the annular seat 120. Moreover, an arc-shaped flange 111 protruding outward is formed at the rear end of each jaw 110, the arc-shaped flange 111 being inserted in the annular recess 121 to connect the jaw 110 to the annular seat 120. The jaws 110 are also axially limited by the fit between the arc-shaped flanges 111 and the annular recess 121. An inwardly recessed groove is formed on an outer wall of each arc-shaped flange 111. A closing spring 130 fitted with the arc-shaped flange 111 to clamp the corresponding jaw 110 is provided at the rear end of the jaw 110, the closing spring 130 being inserted in the groove on the arc-shaped flange 111 and meanwhile rested in the annular recess 121 of the annular seat 120. The closing spring 130 has a ring shape. The closing spring 130 applies a preload against the jaw 110 corresponding thereto, disposing the jaw 110 in a normally closed state. The respective jaws 110 in the closed state tightly gather together. The front ends of the respective jaws 110 in the closed state gather to form a tapered head with a maximum outer diameter D1. When the ejector pin 200 moves forward forcing the respective jaws 110 to switch from the closed state to the separated state, a certain gap being created between two adjacent jaws 110 with the closing springs 130 being compressed to deform, the overall outer diameter of the jaws 110 turning to D2, D2>D1. When the ejector pin 200 moves rearward to release the respective jaws 100, the closing springs 130 recovering from deformation drive the respective jaws 110 to reset from the separated state to the closed state. As an example solution of this implementation, the tube expander 10 may be configured with various specifications of expansion dies 100, the jaws 100 of which have different maximum outer diameters in the closed state so that the tube expander may be applied to expand tubes with various diameters. It may be understood that, the number of jaws 110 in the expansion die 100 is not limited to six, which may also be set to three, four, five, seven, eight, or any other reasonable number. It may be understood that, a plurality of circles of recessed grooves spaced apart in the anteroposterior direction may be arranged on the outer wall of each jaw 110.

[0072] Referring to FIGS. 2 and 3, in this implementation, the drive element 300 drives, via a transmission structure 500, the ejector pin 200 to move forward. Specifically, the drive element 300 comprises the electric motor 310 and a reduction gear mechanism 320, and the transmission structure 500 comprises a rotary shaft 510 and a cam 520. A power shaft of the electric motor 310 is drivingly connected to an input shaft of the reduction gear mechanism 320, and the rotary shaft 510 is drivingly connected to an output shaft of the reduction gear mechanism 320; of course, the output shaft of the reduction gear mechanism 320 may also directly serve as the rotary shaft 510. The cam 520 is fixedly sleeved on the rotary shaft 510, the rotary shaft 510 being rotatably mounted via a bearing; and the rotary shaft 510 and the cam 520 may rotate about central axis C of the rotary shaft 510 as the rotational centerline. Specifically in this implementation, the electric motor 310 drives, via the reduction gear mechanism 320, the rotary shaft 510 to rotate unidirectionally in a direction indicated by , and the rotating rotary shaft 510 drives the cam 520 to rotate synchronously in the direction indicated by . It may be understood that, the reduction gear mechanism 320 may adopt a speed reduction transmission structure such as a multi-stage planetary gear structure satisfying speed reduction transmission requirements.

[0073] Referring to FIG. 1, in this implementation, the tube expander 10 further comprises a housing 600. To appropriately reduce the overall anteroposterior size of the tube expander, the central axis of the electric motor 310 substantially overlaps with the central axis of the rotary shaft 510; in addition, the axial direction of the rotary shaft 510 is exemplarily set perpendicular to the axial direction of the ejector pin 200, i.e., the ejector pin 200 is set perpendicular to the rotary shaft 510 and the electric motor 310; by disposing the electric motor 310 and the reduction gear mechanism 320 in a handle 610 formed by the housing 600 and disposing the components including the cam 520, the ejector pin 200, and the indexing assembly 400 in a main cavity of the housing 600, the overall profile of the tube expander is substantially pistol-shaped. The tube expander 10 in this implementation may be powered by a battery pack or mains electricity. The other structures of the tube expander may refer to conventional technologies, e.g., setting a start/stop switch on the housing 600, or setting a control panel in the housing 600, or mounting the rotary shaft 510 rotatably in the housing 600 via a bearing, etc., which are not detailed here. Of course, the electric motor 310 and the rotary shaft 510 may also be distributed in other patterns, e.g., the axial direction of the rotary shaft 510 and that of the electric motor 310 may be set at an angle or perpendicular to each other; the overall profile of the tube expander may also be set with another reasonable profile dependent on layout of the respective components therein.

[0074] Referring to FIG. 6, as an example solution of this implementation, the ejector pin 200 comprises an ejection rod 210 and a tapered head 220, the ejection rod 210 comprising a rod body 211 extending in the anteroposterior direction, the tapered head 220 being connected to a front end of the rod body 211, the tapered head 220 having a tapered profile that widens progressively from front to rear, an outer diameter of a rear end of the tapered head 220 being greater than that of the rod body 211. To reduce friction between the cam 520 driving the ejector pin 200 to move forward and the ejector pin 200, a rotatable roller 230 is provided at a rear end of the ejector pin 200, an outer peripheral surface of the cam 520 abutting against the roller 230; the rotating cam 520 applies a force against the ejector pin 200 via the roller 230 to drive the ejector pin 200 to move forward. In this implementation, a disc-shaped rear plate 212 is provided at a rear end of the rod body 211, the rear plate 212 being provided with two lugs 213 which protrude rearward and are oppositely arranged, the roller 230 being rotatably mounted between the two lugs 213 via a pin rod 240, two ends of the pin rod 240 being inserted in the holes on the two lugs 213, respectively. The axial direction of the pin rod 240 is exemplarily set parallel to the axial direction of the rotary shaft 510; in addition, the axial direction of the pin rod 240 is exemplarily set perpendicular to the axial direction of the ejector pin 200. Since the roller 230 may rotate circumferentially relative to the pin rod 240, the roller 230 may effectively reduce the contact friction between the cam 520 and the ejector pin 200, so that the cam 520 may smoothly drive the ejector pin 200 to move forward. In this implementation, the tapered head 220 and the rod body 211 are securely fixed together via thread-fitting; of course, the tapered head 220 and the rod body 211 may also be fixed together by other means; or, the tapered head 220 and the rod body 211 may be unitarily formed.

[0075] Referring to FIG. 7, a push surface 521, an avoidance surface 522, and a transition surface 523, which are circumferentially distributed in sequence, are provided on an outer circumferential wall of the cam 520. In FIG. 7, point E represents an end point of a proximal end of the push surface 521, point F represents an end point of a distal end of the push surface 521, and the push surface 521 extends from point E to point F along an involute, i.e., the push surface 521 is substantially a curved surface with an involute profile; point C represents the central axis of the rotary shaft 510, D represents a circle with point C as the center and the distance between point C and point F as the radius, and the radial distance between the push surface 521 and the circular outline represented by D is reduced progressively from point E to point F. In FIG. 7, point G represents a dividing point between the avoidance surface 522 and the transition surface 523, one end of the avoidance surface 522 being smoothly connected to a distal end of the push surface 521, an opposite end of the avoidance surface 522 being smoothly connected to the transition surface 523, two ends of the transition surface 523 being smoothly connected to the proximal ends of the avoidance surface 522 and the push surface 521, respectively, distances between respective points on the avoidance surface 522 and point C being all smaller than the distance between point F and point C, distances between respective points on the transition surface 523 and point C increasing progressively from point G to point E. When the tube expander is operating, the drive element 300 drives, via the rotary shaft 510, the cam 520 to rotate in the direction indicated by in FIG. 7; when the push surface 521 of the cam 520 abuts against the roller 230, the cam 520 drives, via abutment fit between the push surface 521 and the roller 230, the ejector pin 200 to move forward, and the ejector pin 200 moving forward actuates the respective jaws 110 to switch from the closed state to the separated state. When the cam 520 rotates till the avoidance surface 522 abuts against the roller 230, the cam 520 releases the roller 230, so that the ejection rod 210 may move rearward to reset and release the respective jaws 110; under the action of the closing springs 130, the respective jaws 110 may switch from the separated state to the closed state.

[0076] To allow for the ejector pin 200 released by the cam 520 to move rearward timely and smoothly to reset, a reset spring 710 is sleeved outside the ejector pin 200. Specifically in this implementation, the reset spring 710 is sleeved outside the rod body 211, a front end of the reset spring 710 being positionally retained, a rear end of the reset spring 710 abutting against the rear plate 212 of the ejection rod 210. When the ejector pin 200 is driven by the cam 520 to move forward, the reset spring 710 is compressed to be elastically deformed. When the push surface 521 of the cam 520 migrates from the roller 230, the cam 520 releases the ejector pin 200; now, the reset spring 710 recovering from deformation forces the ejector pin 200 to move rearward to reset. When the ejector pin 200 moves rearward to reset in place, the push surface 521 of the cam 520 abuts against the roller 230 again to drive, via the roller 230, the ejector pin 200 to move forward.

[0077] When the avoidance surface 522 on the cam 520 engages the roller 230, the ejector pin 200 is biased by the reset spring 710 so as to be disposed at a rear initial position; now, the respective jaws 110 are in a fully closed state. When the cam 520 moves till point F on the push surface 521 to substantially engage the roller 230, the ejector pin 200 is disposed at a front ejected position; now, the respective jaws 110 are in a fully separated state.

[0078] In this implementation, the tube expander 10 further comprises a supporting sleeve 720 fixedly disposed in the housing 600, the supporting sleeve 720 being sleeved outside the ejector pin 200, a central axis of the supporting sleeve 720 exemplarily substantially overlapping with a central axis of the ejector pin 200. An inner diameter of the supporting sleeve 720 is greater than an outer diameter of the ejector pin 200, and a certain radial interstice is arranged between an outer circumferential wall of the ejector pin 200 and an inner circumferential wall of the supporting sleeve 720. Referring to FIG. 13, a circle of flange 721 protruding toward the center is provided at a front end of the supporting sleeve 720, the reset spring 710 being disposed inside the supporting sleeve 720, a front end of the reset spring 710 abutting against the flange 721 so as to be positionally retained, a rear end of the reset spring 710 abutting on a front surface of the rear plate 212 to engage the ejector pin 200. Two extended portions 722 which are oppositely arranged and extend rearward are provided at the rear end of the supporting sleeve 720, a sliding groove 723 extending in the anteroposterior direction being formed on each extended portion 722, the two ends of the pin rod 240 protruding outward from the lugs 213 to be inserted into the corresponding sliding grooves 723, respectively; when the ejector pin 200 moves relative to the supporting sleeve 720 in the anteroposterior direction, the end portions of the pin rod 240 slide in the sliding grooves 723 in the anteroposterior direction; the ejector pin 200 is circumferentially retained via fit between the pin rod 240 and the sliding grooves 723, preventing the ejector pin 200 from rotating circumferentially during its movement in the anteroposterior direction.

[0079] Referring to FIGS. 8, 9, and 10, in this implementation, the rotary member 410 has a hollow disc shape, the rotary member 410 being sleeved on an outer periphery of the ejector pin 200, one of the outer circumferential wall of the ejector pin 200 and the inner circumferential wall of the rotary member 410 being provided with an interlocking groove 441, the other one thereof being provided with an interlocking block 442, at least a local portion of the groove wall of the interlocking groove 441 being twisted or inclined relative to the central axis of the ejector pin 200, the interlocking block 442 being inserted in the interlocking groove 441; the ejector pin 200 moving forward drives the rotary member 410 to rotate forward via fit between the interlocking groove 441 and the interlocking block 442. Specifically, the rotary member 410 is disposed outside and in front of the supporting sleeve 720, the rotary member 410 being sleeved on the outer periphery of the rod body 211; a central bore 411 is formed at the center of the rotary member 410, a bore diameter of the central bore 411 being slightly greater than the outer diameter of rod body 211; the rotary member 410 may rotate about the central axis indicated by straight line H in FIG. 8 as the rotational centerline. A pin stud 250 is fixed on the rod body 211 of the ejector pin 200, the pin stud 250 being set perpendicular to the rod body 211. Two ends of the pin stud 250 project out of the rod body 211 to form interlocking blocks 442 located on the outer circumferential wall of the ejector pin 200, respectively, the two interlocking blocks 442 being provided and distributed uniformly along the circumferential direction of the rod body 211. Interlocking grooves 441 are provided on a bore wall of the central bore 411. Two interlocking grooves 441 are provided and distributed uniformly along the circumferential direction of the central bore 411, the two interlocking blocks 442 being inserted into the two interlocking grooves 441, respectively. Referring to FIG. 11, each interlocking groove 411 has a first groove wall 441a and a second groove wall 441b which are oppositely arranged, the first groove wall 441a being disposed parallel to the central axis of the rotary member 410 indicated by the straight line H, the second groove wall 441b being twisted relative to the central axis of the rotary member 410 indicated by the straight line H. During forward movement of the ejector pin 200, the interlocking blocks 442 abut against the second groove walls 441b of the interlocking grooves 441 to force the rotary member 410 to rotate forward in the direction indicated by y in FIG. 8. As an optional solution of this implementation, the second groove wall 441b is twisted entirely or partially relative to the central axis of the rotary member 410 indicated by the straight line H, or the second groove wall 441b is inclined entirely or partially relative to the central axis of the rotary member 410 indicated by the straight line H. As an alternative solution of this implementation, the interlocking grooves 441 and the interlocking blocks 442 may swap their positions, i.e., the interlocking grooves 441 are disposed on the outer circumferential wall of the rod body 211, while the interlocking blocks 442 are disposed on the inner circumferential wall of the rotary member 410.

[0080] Referring to FIG. 12, in this implementation, one end of the energy storage member 420 is connected to the rotary member 410, and an opposite end thereof is connected to the supporting sleeve 720; when the rotary member 410 rotates forward, the energy storage member 420 is forced to be deformed. Specifically, the energy storage member 420 exemplarily adopts a tension spring 420a, one end of the energy storage member 420 being provided with a first connecting pin 421 of a hook shape, an opposite end thereof being provided with a second connecting pin 422 of a hook shape. The tension spring 420a as the energy storage member 420 is disposed on an outer periphery of the rotary member 410; moreover, the energy storage member 420 engages the outer circumferential wall of the rotary member 410 so that the energy storage member 420 receives a certain support. The rotary member 410 is provided with a locating block 412 protruding radially outward from its own outer circumferential wall, a hole for the first connecting pin 421 to insert being provided on the locating block 412, the first connecting pin 421 being inserted in the hole on the locating block 412 so that the first connecting pin 421 is in hook connection with the locating block 412; in this way, one end of the energy storage member 420 is connected to the rotary member 410. The supporting sleeve 720 is provided with a securing block 724 protruding forward from the front end surface, and the securing block 724 is located at a circumferential outer portion of the rotary member 410, the securing block 724 and a limiting block 451 being distributed in a spaced apart manner along the circumferential direction of the rotary member 410; a hole for the second connecting pin 422 to insert is provided on the securing block 724, the second connecting pin 422 being inserted in the hole on the securing block 724 so that the second connecting pin 422 is in hook connection with the securing block 724; in this way, the opposite end of the energy storage member 420 is connected to the supporting sleeve 720 to realize positional retainment. When the rotary member 410 rotates forward in the direction indicated by yin FIG. 8, the distance between the limiting block 451 and the securing block 724 increases progressively, so that the tension spring 420a as the energy storage member 420 is stretched to be elastically deformed. When the reset spring 710 drives the ejector pin 200 to move rearward, the energy storage member 420 recovering from deformation imposes a force against the rotary member 410 so that the rotary member 410 rotates reversely in the direction indicated by-y in FIG. 8.

[0081] In this implementation, to limit the rotating angle of forward/reverse rotation of the rotary member 410, one of the rotary member 410 and the supporting sleeve 720 is provided with the limiting block 451, and the other one thereof is provided with a limiting groove 452 extending circumferentially, the limiting block 451 being inserted in the limiting groove 452 to limit the rotating angle of the rotary member 410. Specifically, the rotary member 410 is provided with a limiting block 451 protruding radially outward from its outer circumferential wall, and the supporting sleeve 720 is provided with a boss 725 protruding forward from its front end surface, the boss 725 and the securing block 724 being spaced apart by a certain distance along the circumferential direction of the supporting sleeve 720, a space between the boss 725 and the securing block 724 defining the limiting groove 452, the limiting block 451 being inserted in the limiting groove 452, a rotating angle of the rotary member 410 being limited by fit between the limiting block 451 and the limiting groove 452. When the rotary member 410 rotates forward till the limiting block 451 abuts against the securing block 724, the rotary member 410 rotates in place and cannot rotate further. When the rotary member 410 rotates reversely till the limiting block 451 engages the boss 725, the rotary member 410 rotates in place and cannot rotate further. As an alternative solution of this implementation, the limiting block 451 and the limiting groove 452 may swap their positions.

[0082] Referring to FIGS. 16 and 17, in this implementation, the indexing member 430 has a sleeve shape which progressively widens from front to rear; the indexing member 430 is sleeved outside the ejector pin 200, the indexing member 430 being clearance-fitted with the tapered head 220 of the ejector pin 200, the indexing member 430 being disposed between the rotary member 410 and the jaws 110 in the anteroposterior direction. A rear end surface of the indexing member 430 is spaced by a certain distance from a front end surface of the supporting sleeve 720 in the anteroposterior direction, and the energy storage member 420 is disposed between the rear end surface of the indexing member 430 and the front end surface of the supporting sleeve 720 in the anteroposterior direction; by limiting the energy storage member 420 in the anteroposterior direction via the rear end surface of the energy storage member 420 and the front end surface of the supporting sleeve 720, structural stability of the energy storage member 420 is enhanced. As an optional solution of this implementation, in a case that the rotary member 410 has a large thickness, a groove for receiving the energy storage member 420 may also be formed on an outer circumferential wall of the rotary member 410; by disposing the energy storage member 420 in the groove on the outer circumferential wall of the rotary member 410, the energy storage member 420 is limited in the anteroposterior direction.

[0083] Referring to FIG. 14, in this implementation, the rear end of the indexing member 430 is sleeved on the outer periphery of a front portion of the rotary member 410, a convex tooth 461 is provided on the inner circumferential wall of the rear end of the indexing member 430, and a swingable ratchet 462 is provided on the rotary member 410; when the rotary member 410 rotates forward, the ratchet 462 slips relative to the convex tooth 461 so that the rotary member 410 and the indexing member 430 are drivingly disengaged; when the rotary member 410 rotates reversely, the ratchet 462 abuts against the convex tooth 461 so that the rotary member 410 and the indexing member 430 are drivingly engaged. Specifically, a circle of convex teeth 461 distributed circumferentially at even intervals are arranged on an inner circumferential wall of the rear end of the indexing member 430, and the ratchet 462 is swingably disposed at the front side of the rotary member 410 via a pin 463. The indexing member 430 is further provided with an elastic member 464, one end of the elastic member 464 being positionally retained, an opposite end thereof engaging the ratchet 462; the elastic member 464 forces the ratchet 462 to abut against the convex tooth 461; the elastic member 464 exemplarily adopts a compression spring 464a. When the rotary member 410 rotates forward in the direction indicated by in FIG. 14, the ratchet 462, under the abutment action imposed by the convex tooth 461, overcomes the preload of the compression spring 464a to swing toward the center of the rotary member 410, so that the ratchet 462 slips relative to the convex tooth 461; now, the indexing member 430 and the rotary member 410 rotating forward are in a drivingly disengaged state, so that the rotary member 410 rotating forward cannot drive the indexing member 430 to rotate. When the rotary member 410 rotates reversely in the direction indicated by in FIG. 14, the ratchet 462, under the preload of the compression spring 464a, is in stable abutment against the convex tooth 461; now, the indexing member 430 and the rotary member 410 rotating reversely are in a drivingly engaged state, so that the rotary member 410 rotating reversely may drive the indexing member 430 to rotate in a same direction via fit between the ratchet 462 and the convex tooth 461.

[0084] Referring to FIG. 9, in this implementation, a recessed region 413 is formed on a front side of the rotary member 410, the recessed region 413 being recessed rearward from a front surface of the rotary member 410, the ratchet 462 being swingably disposed in the recessed region 413 via the pin 463; the thickness of the ratchet 462 in the anteroposterior direction is slightly smaller than the depth of the recessed region 413 in the anteroposterior direction so that the ratchet 462 can be completely received in the recessed region 413, preventing the front surface of the ratchet 462 from protruding forward from the front surface of the rotary member 410. Exemplarily, the indexing assembly 400 further comprises a baffle plate 470 held between the front surface of the rotary member 410 and a stepped surface on an inner wall of the indexing member 430, the ratchet 462 being positionally retained by the baffle plate 470 into the recessed region 413, an outer diameter of the baffle plate 470 being substantially equal to or slightly smaller than an outer diameter of the rotary member 410, and a sharp end of the ratchet 462 may project circumferentially out of the recessed region 413 to abut against the convex tooth 461.

[0085] To ensure the strength of driving engagement between the rotary member 410 and the indexing member 430, in this implementation, two ratchets 462 distributed uniformly along the axial direction of the rotary member 410 are provided; correspondingly, two compression springs 464a are also provided in one-to-one correspondence with the ratchets 462. To ensure structural stability of the compression spring 464a, in this implementation, a locating groove 414 is provided on an inner wall of the recessed region 413 facing the sharp end of the ratchet 462; referring to FIG. 15, the ratchet 462 is provided with a protrusion 465 protruding toward the locating groove 414, one end of the compression spring 464a being inserted in the locating groove 414 and abutting against the rotary member 410 so as to be positionally retained, an opposite end of the compression spring 464a being sleeved outside the protrusion 465 and abutting against the ratchet 462. The locating groove 414 and the protrusion 465 play a certain role of positionally retaining the two ends of the compression spring 464a, ensuring that the compression spring 464a may impose a stable action force against the ratchet 462. It may be understood that, the numbers of the ratchets 462 and the compression springs 464a may also be set to one, three, four, or another reasonable number, which are not limited here.

[0086] Referring to FIGS. 4 and 16, an engaging structure 480 is provided between a front end of the indexing member 430 and rear ends of the jaws 110; the rotary member 410 rotating drives, via the engaging structure 480, the jaws 110 to rotate. Specifically, a plurality of first engaging blocks 431 distributed circumferentially at intervals are provided on a front end surface of the indexing member 430, and a plurality of second engaging blocks 112 distributed circumferentially at intervals are provided on a circular rear end surface jointly defined by the jaws 110. In a case that the expansion die 100 is mounted at the front end of the tube expander, the first engaging blocks 431 and the second engaging blocks 112 mesh with each other to constitute the engaging structure 480, so that the rotary member 410 drives, via fit between the rachet 462 and the convex tooth 461, the indexing member 430 to rotate, while the indexing member 430 rotates to drive, via the engaging structure 480, the jaws 110 to rotate synchronously.

[0087] In this implementation, the tube expander further comprises a connecting sleeve 730, the connecting sleeve 730 being secured in the housing 600, a front end of the connecting sleeve 730 projecting forward out of the housing 600, the connecting sleeve 730 being sleeved on an outer periphery of a front portion of the indexing member 430 to limit the indexing member 430 axially; a certain gap is arranged between the connecting sleeve 730 and the indexing member 430, preventing the connecting sleeve 730 from interfering with rotating of the indexing member 430. An outer thread is provided on an outer circumferential wall of the connecting sleeve 730, and an inner thread is provided on an inner circumferential wall of a rear end of the annular seat 120 in the expansion die 100, the annular seat 120 being detachably secured to the front end of the connecting sleeve 730 via fit between the inner thread and the outer thread; the respective jaws 110 are driven to separate by the ejector pin 200 and may be driven to rotate by the indexing member 430.

[0088] Referring to FIGS. 17 and 18, to expand a tube, an expansion die 100 of an appropriate size is selected based on the inner diameter of the tube and mounted on the front end of the tube expander via fitting with the connecting sleeve 730. When the tube expander is operating, the electric motor 310 drives, via the reduction gear mechanism 320, the rotary shaft 510 to rotate in the direction indicated by , the rotary shaft 510 drives the cam 520 to rotate synchronously, the rotating cam 520 drives, via abutment fit with the roller 230, the ejector pin 200 to overcome the preload of the reset spring 710 to move forward, the ejector pin 200 moving forward compresses the reset spring 710 and forces the respective jaws 110 to separate outward, and the separated jaws 110 force the end portion of the tube to expand. Meanwhile, the ejector pin 200 moving forward drives, via fit between the interlocking blocks 442 and the interlocking grooves 441, the rotary member 410 to rotate forward in the direction indicated by Y, and the rotary member 410 rotating forward stretches the tension spring 420a as the energy storage member 420; in addition, when the rotary member 410 rotates forward, the ratchet 462 slips relative to the convex tooth 461; since the indexing member 430 and the rotary member 410 rotating forward are in a drivingly disengaged state, the indexing member 430 will not be driven to rotate by the rotary member 410; as such, the respective jaws 110 will not rotate circumferentially when performing an expansion action.

[0089] After the ejector pin 200 moves forward in place, the cam 520 releases the ejector pin 200, the respective jaws 110 then stop separating, and the reset spring 710 recovering from deformation drives the ejector pin 200 to move rearward to reset; the ejector pin 200 moving rearward releases the respective jaws 110 which close progressively under the action of the closing spring 130. During the process of the reset spring 710 driving the ejector pin 200 to move rearward to reset, the interlocking blocks 442 move rearward relative to the interlocking grooves 441, and the tension spring 420a recovering from deformation imposes a force against the rotary member 410 driving the rotary member 410 to rotate reversely in the direction indicated by ; now, under the action of the compression spring 464a, the ratchet 462 abuts against the convex tooth 461, disposing the indexing member 430 and the reversely rotating rotary member 410 to be in a drivingly engaged state, so that the reversely rotating rotary member 410 drives, via fit between the ratchet 462 and the convex tooth 461, the indexing member 430 to rotate in a same direction, while the rotating indexing member 430 drives, via the engaging structure 480, the respective jaws 110 to rotate by an angle relative to the expanded tube during the closing process. After the ejector pin 200 moves rearward in place, the cam 520 may drive the ejector pin 200 to move forward again forcing the respective jaws 110 to separate for tube expansion.

[0090] In a case that the jaws 110 are stuck so that they cannot be driven by the indexing member 430 to rotate smoothly, the indexing member 430 and the rotary member 410 cannot perform a circumferential rotation either when the ejector pin 200 moves rearward; in this case, since the interlocking groove 441 extends in the anteroposterior direction, the interlocking block 442 and the rotary member 410 cannot get stuck, so that the ejector pin 200 driven by the reset spring 710 can still move rearward to reset, the rearward moving ejector pin 200 forces the tapered head 220 to release the jaws 110, and the released jaws 110 can close progressively under the action of the closing spring 130, which automatically eliminates a possible situation where the jaws 110 get stuck and cannot rotate.

[0091] In this implementation, since the rotary member 410 is driven to rotate under the action of the tension spring 420a recovering from deformation, the power to drive the rotary member 410 is not directly originated from the electric motor 310, so that stalling of the rotary member 410 will not cause increase of the load of the electric motor 310, which helps ensure service life of the electric motor 310.

Second Implementation

[0092] Referring to FIGS. 19, 20, and 21, the tube expander 10 is provided with a control panel 810 disposed in the housing 600 and a switch 820; the electric motor 310 of the drive element 300 is controlled by the control panel 810; the switch 820 is electrically connected to the control panel 810 and operable to start/stop the electric motor 310. The ejector pin 200 is driven by the electric motor 310 to move back and forth between the initial position and the ejected position; the process of the ejector pin 200 moving forward from the initial position to the ejected position and then moving rearward from the ejected position to the initial position constitutes a cycle of movement of the ejector pin 200, and the switch 820 operable to start/stop the electric motor 310 may indirectly start/stop the cycle of movement of the ejector pin 200.

[0093] On this basis, the tube expander 10 is further provided with a detector 830, the detector 830 being electrically connected to the control panel 810 and operable to directly or indirectly detect a position of the ejector pin 200. In this implementation, to allow for the detector 830 to successfully detect a position of the ejector pin 200, the tube expander 10 further comprises a trigger 840 maintaining synchronization with the ejector pin 200; at a predetermined node of the cycle of movement, the trigger 840 moves till corresponding to the detector 830 to trigger the detector 830, whereby the trigger 830 detects the position of the ejector pin 200. Specifically, synchronization between the trigger 840 and the ejector pin 200 refers to movement consistency therebetween during the cycle of movement of the ejector pin 200, so that the trigger 840 can directly or indirectly indicate the position of the ejector pin 200. For example, the trigger 840 may be disposed on the ejector pin 200 to directly indicate the position of the ejector pin 200; the trigger 840 may also be disposed on the pin 240 or the cam 520 to indirectly indicate the position of the ejector pin 200; the trigger 840 may also be disposed on a planetary gear of the reduction gear mechanism 320 or a planetary carrier of the reduction gear mechanism 320 or the rotary member of the electric motor 310 to indirectly indicate the position of the ejector pin 200; this implementation has no specific limitation to the position of the trigger 840. In a specific solution of this implementation, the detector 830 may adopt a magnetic sensor such as a Hall sensor and a reed switch, in which case the trigger 840 is configured as a magnet. The detector 830 may also adopt a photoelectrical sensor, in which case the trigger 840 can be configured as a light blocking plate that blocks light or a reflective part that reflects light or a hole for light to pass through dependent on a specific type of the photoelectrical sensor. The detector 830 may also adopt a microswitch, in which case the trigger 840 is configured as a boss or a pin operable to press an elastic plate of the microswitch. This implementation has no specific limitation to the type of the detector 830, and the trigger 840 may be reasonably set as per the type of the detector 830.

[0094] In this implementation, a handle 610 is provided thereon with a manipulator 850 corresponding to the switch 820, the manipulator 850 being manipulated by a user. The switch 820 is normally in an off state; when the user presses the manipulator 850, the switch 820 is triggered to switch from an off state to an on state. When the user releases the manipulator 850, the manipulator 850 releases the switch 820 so that the switch 820 switches from the on state to the off state. In a specific solution of this implementation, the switch 820 may adopt a microswitch, in which case the manipulator 850 is configured as a trigger or a button or the like operable to trigger the microswitch; the switch 820 may also adopt a touch-screen switch, in which case the manipulator 850 is not provided; of course, the switch 820 may also adopt another type, and the manipulator is configured as per the type of the switch, only required to satisfy a purpose of triggering the switch.

[0095] When the user presses the manipulator 850 so that the switch 820 switches from the off state to the on state, the control panel 810 commands the electric motor 310 to be energized to operate according to an on signal of the switch 820, whereby the electric motor 310 drives, via the reduction gear mechanism 320 and the transmission structure 500, the ejector pin 200 to move, and then the cycle of movement of the ejector pin 200 starts. To allow for the respective jaws 110 to close after each operation of the user, when the user releases the manipulator 850 before the ejector pin 200 returns to the initial position, the switch 820 switches from the on state to the off state; now, the electric motor 310 is still in an energized and operating state till the ejector pin 200 returns to the initial position where the trigger 840 corresponds to the detector 830 so that the detector 830 is triggered by the trigger 840; then, the control panel 810 determines, based on the trigger signal from the detector 830, that the ejector pin 200 is located at the initial position and the jaws 110 are in the closed state, i.e., the ejector pin 200 reaches the predetermined node of the cycle of movement; on this basis, the control panel 810 commands the electric motor 310 to shut down and stop driving; as such, the ejector pin 200 would stop at the initial position after each operation of the user, allowing for the jaws 110 of the expansion die 100 to be disposed in the closed state after each operation of the user, facilitating the user to remove the expansion die 100 off the tube.

[0096] Of course, the predetermined node of the cycle of movement of the ejector pin 200 is not limited to the initial position of the ejector pin 200, which may also be set at any other position than the ejected position.

[0097] The other structures and/or contents of the second implementation are identical to those of the first implementation, which are not detailed here.

[0098] In addition to the example implementations described supra, the present disclosure also has other implementations. Those skilled in the art may make various changes and modifications to the present disclosure, and all such modifications and changes without departing from the spirits of the present disclosure shall fall within the scope of protection limited in the claims appended hereto.