Patent Publication Number: US-2023150082-A1

Title: Transfer machine

Description:
The present invention refers to the field of transfer machines; in particular, the present invention relates to a transfer machine for cold plastic deformation and/or chip removal processing of at least one tubular profile. Such processed tubular profiles are then intended for the technical automotive sector or the thermo-hydraulic sector. 
     Transfer machines for cold forming of tubular profiles using pneumatically or hydrodynamically actuated work units are known in the prior art. Indeed, the transfer machines of the prior art obtain the necessary thrust forces for the cold plastic deformation of tubular profiles with variable diameter and thickness by using pneumatic or hydrodynamic actuators. 
     Transfer machines that use mixed actuation work units, i.e., partly electromechanical and partly pneumatic/hydrodynamic are also known. Such transfer machines require the electromechanical actuator to be replaced by at least one pneumatic and/or hydrodynamic actuator capable of generating sufficient thrust to deform the tubular profile during the deformation process. 
     The presence of supply circuits for pressurized fluids is still necessary in both of the aforesaid cases, whether the transfer machine is actuated entirely by actuators fed by pressurized fluids or has a mixed actuation integrating electromechanical and pneumatic/hydrodynamic actuators. 
     It is known that the presence of conduits or supply circuits for feeding pressurized fluids complicates the design and assembly of the transfer machine. An example of a transfer machine for mechanical processing according to the prior art is described in WO2018/172952A1. 
     Disadvantageously, a transfer machine comprising circuits for pressurized fluids is not only structurally complex but also dangerous. Indeed, the mechanical components delivering pressurized fluids require higher safety standards, continuous monitoring and frequent maintenance. Compliance with such safety standards results in higher costs to ensure the correct and safe operation of the transfer machine. 
     It is the object of the present invention to suggest a transfer machine for cold plastic deformation and/or chip removal processing capable of avoiding, at least in part, the drawbacks complained above relative to the transfer machines according to the prior art. 
     Said object is achieved by a transfer machine for cold plastic deformation and/or chip removal processing according to claim  1 . The dependent claims describe preferred embodiments of the invention. 
    
    
     
       The features and advantages of the transfer machine according to the invention will be apparent from the following description which illustrates preferred embodiments, given by way of indicative, non-limiting examples, with reference to the accompanying figures, in which: 
         FIG.  1    shows a perspective view of a transfer machine according to the invention; 
         FIG.  2    shows a further perspective view of the transfer machine in  FIG.  1   ; 
         FIG.  3    shows an electromechanical work unit according to a further embodiment; 
         FIG.  4    shows the electromechanical work unit according to a further embodiment; 
         FIG.  5    shows the electromechanical work unit according to a yet further embodiment, and 
         FIG.  6    shows the electromechanical work unit according to a further embodiment. 
     
    
    
     In said drawings, a transfer machine according to the invention is indicated by reference numeral  1  as a whole. 
     In a general embodiment, a transfer machine  1  for cold plastic deformation and/or chip removal processing of at least one tubular profile is suggested. Such a transfer machine comprises a base  11 , a mounting table  12 , a rotary table  13  and a plurality of electromechanical work units  2 ; 3 ; 4 ; 5 . The base  11  allows the resting on a base surface B. The mounting table  12  is fixed and arranged orthogonally to the base plane B. The rotary table  13  faces the mounting table. The electromechanical work units  2 ; 3 ; 4 ; 5  are installed on said mounting table  12 . 
     The rotary table  13  comprises a plurality of work stations  131 , where each work station of said plurality of work stations comprises a vise  132  for clamping the tubular profile. 
     According to an embodiment, the vise  132  comprises a pair of half-jaws, wherein the first half-jaw of said pair of half-jaws is fixed and the second half-jaw is movable. 
     Advantageously, the movable half-jaw adapts to the possible variations of the diameter of the tubular profile to be processed, making the transfer machine flexible relative to the various types of tubular profiles. 
     According to an aspect of the invention, a plurality of housing seats  121  are formed in the mounting table  12  and each housing seat of such a plurality of housing seats  121  faces a respective work station. Each housing seat is further suitable for accommodating an electromechanical work unit of said plurality of electromechanical work units. 
     Each electromechanical work unit  2 ; 3 ; 4 ; 5  comprises a first advance group  21 ; 31 ; 41 ; 51 . Such a first advance group comprises, in turn, a first advance motor  22 ; 32 ; 42 ; 52 , a first advance recirculating ball screw  23 ; 33 ; 43 ; 53 , a first advance nut  24 ; 34 ; 44 ; 54  and a first tubular stem  25 ; 35 ; 45 ; 55 . 
     According to an embodiment, the first advance motor  22 ; 32 ; 42 ; 52  is electric. 
     According to an aspect of the invention, the first advance recirculating ball screw  23 ; 33 ; 43 ; 53  is moved by the first advance motor and extends along a first advance screw axis V′ which is substantially orthogonal to the mounting table  12 . The first advance nut  24 ; 34 ; 44 ; 54  is engaged by the first advance recirculating ball screw and is translable along the first advance screw axis V′. The first tubular stem  25 ; 35 ; 45 ; 55  extends between a first stem proximal end  25 ′; 35 ′; 45 ′; 55 ′ and a first stem distal end  25 ″; 35 ″; 45 ″; 55 ″. The first stem proximal end is engaged to the first advance nut and made integral therewith while the first stem distal end is suitable for defining the advancement and/or positioning of a first tool holder element  36 ; 46 ; 56 . 
     In the present discussion, the term “proximal” identifies an element which is close to, or that stretches towards a generic motor member. Conversely, the term “distal” identifies an element which is far, or distanced, from the generic motor member. 
     According to an embodiment, the at least one tubular profile is made of a material belonging to the steel or aluminum alloy family. 
     According to an embodiment shown in the accompanying  FIGS.  3 ,  4  and  6   , the first advance motor  22 ; 32 ; 52 , the first advance recirculating ball screw  23 ; 33 ; 53 , the first advance nut  24 ; 34 ; 54  and the first tubular stem  25 ; 35 ; 55  are coaxial. 
     According to the embodiment shown in  FIG.  3   , the electromechanical work unit  2  has a maximum linear stroke of 150 mm. 
     According to an embodiment shown in the accompanying  FIGS.  4  and  5   , the at least one electromechanical work unit  3 ; 4  further comprises a rotation group  311 ; 411 . Said rotation group  311 ; 411  comprises a rotation motor  321 ; 421 , a first tool holder element  36 ; 46  and a rotation motion transmission system  323 ; 423 . The rotation motor  321 ;  421  comprises, in turn, a rotation motor shaft  322 ; 422  which extends along a rotation motor axis M″ parallel to the first advance screw axis V′. The first tool holder element  36 ; 46  is provided with a tool holder element hub  327 ; 427 . The rotation motion transmission system  323 ; 423  comprises transmission means suitable for connecting the rotation motor  321 ; 421  to the tool holder element hub  327 ; 427 . In particular, the tool holder element hub  327 ; 427  defines the rotation of the first tool holder element  36 ; 46  about a tool holder element rotation axis R which is either parallel or coaxial to the first advance screw axis V′. 
     According to the accompanying  FIGS.  4  and  5   , the transmission means comprise a rotation driving pulley  324 ; 424 , a rotation driven pulley  325 ; 425 , and a rotation transmission belt  326 ; 426 . The rotation driving pulley  324 ; 424  is engaged to the rotation driving shaft  322 ; 422 . The rotation transmission belt  326 ; 426  allows the transmission of rotation motion from the rotation driving pulley  324 ; 424  to the rotation driven pulley  325 ; 425 . In detail, the tool holder element hub  327 ;  427  is engaged to the rotation driven pulley  325 ; 425  and made integral therewith. 
     According to the embodiment shown in  FIG.  4   , the electromechanical work unit  3  is suitable for generating a rototranslational motion. In particular, the first advance motor  32  generates an axial thrust motion with a maximum stroke of 150 mm, while the rotation motor  321  defines the rotation of the first tool holder element  36 . The tool holder element hub  327  is further keyed onto the first tool holder element  36  to define the rotation of said first tool holder element  36  about the tool holder element rotation axis R. 
     According to an embodiment, the first tubular stem  35  comprises a first stem first portion and a first stem second portion. The first stem first portion extends from the first stem proximal end  35 ′ and the first stem second portion terminates with the first stem distal end  35 ″. The cross-section dimensions of the first stem first portion are different from the cross-section dimensions of the second stem second portion. Furthermore, the first stem first portion is connected to the first stem second portion by a stem connection flange. 
     According to the embodiment shown in  FIG.  5   , the electromechanical work unit  4  is suitable for generating a rototranslational motion. In particular, the first advance motor  42  generates an axial position motion with a maximum stroke of 100 mm, while the rotation motor  421  defines the rotation of the first tool holder element  46 . The tool holder element hub  427  is further keyed onto the first tool holder element  46  to define the rotation of said first tool holder element  46  about the tool holder element rotation axis R. 
     According to the embodiment shown in  FIG.  6   , the at least one electromechanical work unit  5  further comprises a second advance group  511 . Said second advance group  511  comprises a second advance motor  521 , a second advance recirculating ball screw  531 , a second advance nut  541 , a second advance flange  542  and a second tubular stem  551 . 
     The second advance recirculating ball screw  531  extends along a second advance screw axis V″ which is parallel to the first advance screw axis V′. Furthermore, such a second advance recirculating ball screw is moved by the second advance motor  521 . The second advance nut  541  is engaged by the second advance recirculating ball screw  531  and is translable along the second advance screw axis V″. The second advance flange  542  is engaged to the second advance nut  541  and made integral therewith. The second tubular stem  551  extends between a second stem proximal end  551 ′ and a second stem distal end  551 ″. The second stem proximal end is engaged to the second advancement flange  542  and made integral therewith while the second stem distal end is suitable for defining the advancement and/or positioning of a second tool holder element. In particular, the second tubular stem  551  is coaxial to the first tubular stem  55 . 
     The electromechanical work unit  5  shown in  FIG.  6    is suitable for generating two mutually independent axial motions. In detail, the first axial thrust motion is generated by means of the first tubular stem  55  while the second axial thrust motion is generated by the second tubular stem  551 . It is worth noting that the order of performance of the two axial motions is reversible, i.e., the thrust of the first tubular stem  55  may precede that of the second tubular stem  551  or vice versa. 
     According to the embodiment shown in  FIG.  6   , the electromechanical work unit  5  is suitable for generating two independent axial motions to perform two different deformation processes on the tubular profile, e.g. an external deformation and an internal deformation of the tubular profile. In detail, the stroke of the first tubular stem  55  and/or second tubular stem  551  varies from a minimum of 49 mm to a maximum of 160 mm. 
     According to an embodiment, the first advance nut  24 ; 34 ; 44 ; 54  is substantially a hollow cylinder which extends between an advance nut proximal end  24 ′; 34 ′; 44 ′; 54 ′ and a first advance nut distal end  24 ″; 34 ″; 44 ″; 54 ″. The first advance nut  24 ; 34 ; 44 ; 54  is further provided with a first collar  240 ; 340 ; 440 ; 540  which protrudes radially outwards and is formed at the first advance nut proximal end ( FIGS.  3  and  5   ) or the first advance nut distal end ( FIGS.  4  and  6   ). In other words, when the first collar protrudes from the first advance nut distal end, the first advance nut is substantially reverse mounted. 
     Advantageously, it is possible to reduce the axial dimensions of the electromechanical work unit when the first advance nut is mounted upside down. 
     Furthermore, the first collar  240 ; 340 ; 440 ; 540  defines an engagement surface for the first stem proximal end  25 ′ or for a first advance flange  350 ; 450 ; 550  which is engaged to both the first advance nut  24 ; 34 ; 44 ; 54  and the first stem proximal end  35 ′; 45 ′; 55 ′ and made integral therewith. 
     According to an embodiment shown in  FIGS.  4  and  6   , the first advance flange  350 ; 550  is axially symmetrical. In particular, a first flange hole  3500 ; 5500  is engaged by the first advance recirculating ball screw  33 ; 53  is centrally formed in the first advance flange  350 ; 550 . Said first flange hole  3500 ; 5500  comprises a stepped chamfer  3501 ; 5501  suitable for engaging the first advance flange  350 ; 550  to the first advance nut  34 ; 54  and make it integral therewith. The first advance flange  350 ; 550  is further delimited by a first flange perimeter region  3502 ; 5502  suitable for engaging the first advance flange  350 ; 550  to the first stem proximal end  35 ′; 55 ′ and make it integral therewith. 
     According to an embodiment, the first tool holder seat  25 ″; 35 ″; 45 ″ is obtained at the first stem distal end  260 ; 360 ; 460 . 
     According to the accompanying  FIGS.  3   , the first tool holder seat  260  is suitable for housing a plastic deformation unit or a chip removal unit. For example, the plastic deformation unit is a rolling unit, or a heading, rounding or facing unit. 
     According to the accompanying  FIGS.  4  and  5   , the first tool holder seat  360 ; 460  is suitable for housing the first tool holder element  36 ; 46 . Such a first tool holder element  36 ; 46  is suitable for being removably equippable with at least one tool for cold plastic deformation or for chip removal of the tubular profile. 
     According to the embodiment shown in  FIGS.  4  and  5   , the first tool holder element  36 ; 46  is a shaft in which a tool seat  361 ; 461  is centrally formed suitable for housing a forming unit or a chip removal unit. 
     According to the embodiment in  FIG.  6   , the first tool holder element  56  forms releasable coupling means  561 , e.g. a shape coupling, by interference or bolted with the deformation unit. 
     According to the embodiment shown in  FIG.  6   , the first stem distal end  55 ″ is engaged to an advance flange tool holder element  543  and made integral therewith. A blind tool holder element  5430  housing the first tool holder element  56  is obtained in the advance flange of tool holder element  543 . 
     Advantageously, the tool element seat  5430  promotes the centering of the first tool element  56  relative to the tool holder element advance flange  543 . 
     The tool holder element advance flange  543  is further integral with the first tool holder element  56  and is provided with a centering tang  5431  which protrudes proximally towards the first advance motor  52  along the first advance screw axis V′. Said centering tang  5431  is at least partially housed in a recess  530  obtained in the first advancement recirculating ball screw  53 . Said recess  530  is circumferentially delimited by a recess wall and the centering tang  5431  is never in contact with said recess wall. In other words, the recess  530  is simply a notch for housing the centering tang  5431  and there is no contact between the centering tang  5431  and the recess wall. 
     According to the embodiment shown in  FIG.  6   , the second advance motor  521  is engaged to the second advance recirculating ball screw  531  by means of a bellows joint  571 . 
     Advantageously, the bellows joint allows the correction of possible misalignments between the second advance motor and the second advance recirculating ball screw. Therefore, the bellows joint facilitates the assembly of the electromechanical work unit. 
     According to a further advantageous aspect, the bellows joint improves the torsional resistance at the interface between the second advance motor and the second advance recirculating ball screw. 
     According to the accompanying  FIG.  6   , the second advance nut  541  is provided with a second collar  5410  suitable for engaging the second advance nut  541  and make it integral with the second advance flange  542 . 
     According to an embodiment shown in  FIG.  6   , a second tool holder seat  560  suitable for housing the second tool holder element is obtained at the second stem distal end  551 ″. Such a second tool holder element is removably equippable with at least one tool for plastic deformation or for chip removal of the tubular profile. 
     According to an embodiment shown in  FIG.  5   , the transfer machine further comprises a first rotation motion transmission system  413 . Such a first rotation motion transmission system  413  comprises a first rotation driving pulley  414 , a first rotation driven pulley  415  and a first rotation transmission belt  416 . The first rotation driving pulley  414  is engaged to a first rotation driving shaft  411  of the first advance motor  42 . The first rotation transmission belt  416  transmits the motion from the first rotation driving pulley  414  to the first rotation driven pulley  415 . Furthermore, the first rotation driven pulley  415  is engaged to the first advancement recirculating ball screw  43  and made integral therewith. The first rotation driving shaft  411  extends along a first advance motor axis M′ which is either parallel to or coincident with the first advance screw axis V′. 
     According to the embodiment shown in the accompanying  FIG.  4   , the first tool holder element  36  is provided with a first centering tang  3431  protruding proximally towards the first advance motor  32  along the first advance screw axis V′. Said first centering tang  3431  is at least partially housed in a first recess  330  obtained in the first advancement recirculating ball screw  33 . Said first recess  330  is circumferentially delimited by a first recess wall and the first centering tang  3431  is never in contact with said first recess wall. In other words, the first recess  330  is simply a notch for housing the first centering tang  3431  and there is no contact between the first centering tang  3431  and the first recess wall. 
     According to an embodiment, each electromechanical work unit  2 ; 3 ; 4 ; 5  comprises an external covering frame  200 ; 300 ; 400 ; 500  made of anodized aluminum, e.g. aluminum of the  7000  series. In particular, the external covering frame is made of hard-anodized aluminum. The hard anodizing process makes it possible to obtain a hardened surface layer with a depth comprised between 20 and 35 microns. 
     Advantageously, the external covering frame, being made of aluminum, allows obtaining an electromechanical work unit, which is light enough to be installed cantilevered in the housing of the mounting table. 
     According to a further advantageous aspect, the external covering frame, being made of anodized aluminum, allows obtaining a good compromise between superficial hardness and lightness. 
     According to an embodiment shown in the accompanying  FIGS.  3 ,  4  and  6   , the first advance motor  22 ; 32 ; 52  is a hollow shaft motor. 
     According to an embodiment, each electromechanical work unit  2 ; 3 ; 4 ; 5  comprises an external covering frame  200 ; 300 ; 400 ; 500  which extends between a proximal frame portion  200 ′; 300 ′; 400 ′; 500 ′ and a distal frame portion  200 ″; 300 ″; 400 ″; 500 ″. The distal frame portion  200 ″; 300 ″; 400 ″; 500 ″ comprises an external cylindrical surface  201 ; 301 ; 401 ; 501  proximally delimited by a shoulder  210 ; 310 ; 410 ; 510 , or a spacer, and distally delimited by a locking ring nut  220 ; 320 ; 420 ; 520 . The space region extending between the shoulder  210 ; 310 ; 410 ; 510 , or the spacer, and the locking ring nut  220 ; 320 ; 420 ; 520  is suitable for being housed in one of the plurality of housing seats  121  of the mounting table  12 . In particular, the locking ring nut  220 ; 320 ; 420 ; 520  is screwed onto the external cylindrical surface  201 ; 301 ; 401 ; 501  until it comes into contact with the surface of the mounting table  12  facing the rotary table  13 . Instead, the shoulder  210 ; 310 ; 410 ; 510  abuts onto the surface of the mounting table  12  opposite to the surface facing the rotary table  13 . In this manner, each electromechanical work unit is installed and locked in one of the plurality of housing seats  121 . 
     Innovatively, the transfer machine according to the present invention complies with the intended purpose; indeed, it comprises fully electromechanical work units which do not suffer from the disadvantages due to the presence of pneumatic or hydrodynamic actuators discussed above. In other words, the transfer machine according to the present invention is suitable for plastically deforming a tubular profile by means of electromechanically actuated work units without the need for pneumatically or hydrodynamically actuated actuators. The force generated by the electromechanical work units is sufficient to eliminate the presence of pressurized fluid and the respective control unit. 
     Furthermore, the transfer machine is safe, because it comprises only electromechanical work units capable of generating sufficient thrust force to deform the tubular profile. In other words, the electromechanical work units do not require the additional presence of pneumatic/hydrodynamic actuators or, in any case, of components subjected to the action of pressurized fluid. 
     The second advantage is that the transfer machine allows a reduction in costs due to the fact that the work units are completely electromechanical. The structure of the transfer machine is simplified because the electromechanical work units are not equipped with oil or fluid pressure tanks, control units or oil/fluid recovery systems. A further cost reduction is attributable to the fact that there is no need to dispose of the waste oil produced by the use of electromechanical work units and that the transfer machine requires less monitoring and maintenance than a transfer machine with completely pneumatic or hydrodynamic actuation. 
     In a further advantageous aspect, the electromechanical work unit is suitable for generating a deformation thrust of up to 7000 kg. 
     A person skilled in the art may make changes and adaptations to the embodiments of the transfer machine according to the invention or can replace elements with others which are functionally equivalent to satisfy contingent needs without departing from the scope of protection of the following claims. All the features described above as belonging to one possible embodiment may be implemented independently from the other described embodiments.