Tube expander

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.

I/We claim: 
     
         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.