Welding machine for welding terminals of a stator to a busbar for the production of an electric motor and related method

Abstract

Welding machine for welding terminals of a stator to respective seats of a busbar for the production of an electric motor, said machine comprising a plurality of operating stations and at least one movable support configured to hold a stator and to position it within each of the operating stations of the welding machine, wherein said operating stations comprise at least one assembly station configured to assemble the busbar onto the stator, aligning said terminals with the respective seats, a welding station comprising a welding head configured to weld the terminals of the stator to the seats of the busbar, wherein said machine further comprises a rotation member arranged in correspondence of said welding station and configured to rotate said movable support about an axis of the rotation member and a programmable control unit in communication with at least said welding station and configured to receive dimensional data related to said stator and / or said busbar, said welding station being configured to move said welding head along at least one vertical axis and at least one horizontal axis based on the received dimensional data.

Description

[0001] Welding machine for welding terminals of a stator to a busbar for the production of an electric motor and related method DESCRIPTION

[0002] The present invention relates to a welding machine for welding terminals of a stator to a busbar for the production of an electric motor.

[0003] In the technical field of electric motors, it is known to use wiring structures, generally known as busbars, to make electrical connections between the electrical circuits of the stator of the motor.

[0004] Typically, the fixing of the busbar to the stator involves inserting the terminals of the stator in specifical seats made in the busbar and their subsequent welding. Terminal means the aggregate group of conductive terminal wires of an electrical circuit.

[0005] This process can therefore significantly affect the production time of the motor, as well as the machining precision. In fact, the prior art does not provide for solutions capable of sufficiently automating these production steps and allowing for the versatility that, on the contrary, would be desirable to have in the busbar fixing steps.

[0006] The known machines are in fact not suitable for carrying out these steps for the production of the electric motors.

[0007] The Applicant has observed how the known solutions do not allow to make the plurality of welds, placed in predetermined positions, variable according to the type of motor, required for the electrical connection of the terminals of the busbar to the terminal wires, twisted or not, of the stator. The technical problem underlying the present invention is therefore to provide a welding machine and related method that is structurally and functionally conceived to at least partially obviate one or more of the drawbacks complained of with reference to the cited prior art.

[0008] Within the scope of this problem, an object of the present invention is to provide a welding machine and related method that is capable of welding the terminals of a stator to a busbar.

[0009] It is also an object of the invention to provide a welding machine and related method that allows the welding of stators and busbars of different types and sizes.

[0010] Another object is to provide a welding machine and related method that allows to automatically detect the different types and sizes of stator and busbar to be welded and adapt the type and welding positions automatically. Preferably, the detection of the type of stator and busbar arrives as information to the machine via data transmitted with TAG+RFID or via the network, via HOST-PC, or via an affixed DATAMATRIX code (usually laser printed) on the side of the stator itself.

[0011] This problem is solved and one or more of these objects are at least in part achieved by the invention, based on a first aspect, by means of a welding machine for welding terminals of a stator to a busbar for the production of an electric motor comprising a plurality of operating stations.

[0012] According to preferred embodiments, the machine further comprises at least one movable support configured to hold a stator and position it within each of the operating stations of the welding machine.

[0013] In this way, it is the stator the one moving within the machine to be subjected in each operating station to a specific machining step.

[0014] Said operating stations preferably comprise at least one assembly station at which the busbar is assembled on the stator, aligning the terminals with the respective seats.

[0015] According to preferred embodiments, the machine further comprises at least one welding station at which the terminals of a stator are welded to the busbar.

[0016] In this way, the machine is able to operate on more than one stator at the same time as it is possible to perform welding in the welding station, while performing assembly in the assembly station.

[0017] Thanks to these characteristics, it is possible to produce a machine with a high production efficiency.

[0018] In some embodiments, said welding station comprises a welding head configured to weld the terminals of a stator to the busbar.

[0019] In some embodiments, the welding head is configured to perform a resistance welding. Resistance welding is also known in the industry as wire fusing or hot crimping. This resistance welding provides that the welding head comprises two electrodes configured, first, to exert a pressure on a seat of the busbar, obtaining a deformation thereof aimed at crimping the seat of the busbar with the terminal inserted inside, and to transmit thermal energy by Joule effect by closing the electrical circuit through the seat of the busbar and the crimped terminal. The transmission of thermal energy will allow to melt, at least partially, the material of the elements to be mutually welded.

[0020] The welding head used for resistance welding comprises a first welding electrode and a second ground electrode.

[0021] Preferably, the welding head comprises a water cooling device configured to cool the welding electrode.

[0022] Preferably, the welding head is configured to perform spot welding.

[0023] Preferably, the welding head comprises a pneumatic actuator configured to move at least one of the two electrodes so as to exert a pressure on the component to be welded. In particular, said pneumatic actuator comprises a pneumatic cylinder fed by a closed-loop proportional valve and a linear displacement transducer of the inductive type or LVDT (Linear Variable Displacement Transducer). As an alternative to the pneumatic actuator, an electromechanical type linear actuator can be used. Furthermore, some embodiments provide for the use of the pneumatic actuator provided in the preferred form, further combined with an electromechanical actuator, comprising a servomotor, wherein the servomotor is configured for the movement of the welding electrode while the pneumatic actuator is configured for the movement of the ground electrode. In such embodiments, the welding head will further comprise a load cell configured to measure the force exerted by the electromechanical actuator on the component to be welded (seat of the crimped busbar).

[0024] Preferably, the welding head will be connected to an alternating current or direct current generator (inverter). In the embodiments comprising an inverter, it is configured to generate direct current to be applied to the crimped seat through the electrodes in the closed position that momentarily close the electrical circuit.

[0025] Preferably, the current in output from the inverter will have a frequency between 1 kHz and 20 kHz.

[0026] In the embodiments provided with inverters, the machine may advantageously comprise an air cooler configured to cool the inverter.

[0027] Preferably, the welding head comprises a voltage sensor or voltmeter configured to measure the voltage between the welding electrode and the ground electrode.

[0028] Preferably, the welding head comprises an electric current sensor or ammeter configured to measure the electric current in output from the welding electrode.

[0029] The machine preferably comprises a rotation member arranged in correspondence of the welding station and configured to rotate said movable support about an axis of the rotation member.

[0030] The machine preferably comprises a programmable control unit in communication with at least said welding station.

[0031] The welding station is preferably configured to receive dimensional data related to said stator and / or said busbar from said programmable control unit.

[0032] Preferably, the detection of the type of stator and busbar arrives as information to the machine via data transmitted with TAG+RFID. Alternatively, this information can arrive via the network, via HOST-PC, or via an affixed DATAMATRIX code (QR Code) (usually printed with laser marking) on the side of the stator itself.

[0033] Advantageously, said welding station is configured to move said welding head along a vertical axis Z and at least along a horizontal axis X based on the received dimensional data of the stator and busbar. It is specified that the vertical Z and horizontal X axes are perpendicular to each other. The stroke along the horizontal axis X will allow the correct radial positioning of the welding head with respect to the terminal of the stator and respective seat of the busbar to be welded. In the embodiments where resistance welding is provided, once the desired radial position is reached, the electrodes will be moved until the busbar terminal is engaged and a crimping pressure applied. The movement of the electrodes can advantageously be carried out in a radial direction, i.e. substantially parallel to the horizontal axis X.

[0034] Some embodiments provide that the welding head is further configured to move the welding head along a third transverse axis Y. This transverse axis Y is perpendicular to the vertical axis Z and the horizontal axis X. In such embodiments, the vertical Z, horizontal X and transverse Y axes form a three-dimensional Cartesian system X, Y, Z. In such embodiments, when resistance welding is provided, the welding head can be suitably moved along the transverse axis Y. In the embodiments in which resistance welding is provided, the third movement axis will allow to carry out crimping oriented differently from the embodiment in which it is possible to move the welding head on the horizontal plane only along the radial horizontal axis X. By doing so, it will be possible to weld along different axes to the horizontal axis X, for example along two mutually perpendicular axes X, Y.

[0035] Each of these features contributes to creating a machine capable of welding the terminals of a stator to the busbar by automatically reaching the plurality of welding points.

[0036] Thanks to the dimensional data related to said stator and / or said busbar received by the welding station, it is possible to operate on stators and relative busbars of different type and size by performing an automatic format change.

[0037] In some embodiments, the present invention provides that the operating stations further comprise a feeding station upstream of the assembly station and a finishing station downstream of the welding station. In this finishing station it will be possible to perform auxiliary assemblies on the stator, wait for the weld to cool or carry out control actions of the visual type.

[0038] In this way, it is possible to optimize the working cycle of the machine, performing each activity on the stator in a specific dedicated station.

[0039] Thanks to this feature, it is in fact possible to process several stators at the same time and at least one for each operating station.

[0040] In some embodiments, the present invention also refers to a machine comprising a turntable comprising at least one support, and configured to rotate around a central axis of symmetry to bring said at least one support in correspondence with each operating station.

[0041] Thanks to this feature, it is possible to create a machine with a particularly compact layout configuration that allows an optimisation of the space occupied and an optimisation of the operator's working area.

[0042] According to a preferred embodiment, the turntable comprises as many supports as there are operating stations.

[0043] This feature also contributes to the possibility of treating several stators at the same time and at least one for each station.

[0044] Preferably, said supports are arranged equidistant from each other on said turntable along a circumference coaxial to the axis of symmetry.

[0045] This feature makes it possible to perform rotations of the turntable with a pitch equal to the distance between the supports to perform the transfer of each stator to the next operating station.

[0046] In some embodiments, each support is fixed in a rotatable manner to the turntable.

[0047] In this way, it is possible to rotate the stator to facilitate operational and control activities.

[0048] Advantageously, the machine comprises a rotation member arranged in correspondence of the welding station and configured to rotate the support around the axis of the rotation member. This rotation member is also referred to as an "indexer" or angular divider member.

[0049] This permits that the relative position between the stator with said busbar and the welding head can be changed in order to weld said stator and said busbar in a plurality of welding points thereof. In the embodiments in which it is provided for the welding head to be movable along the third transverse axis Y, the use of the rotation member further allows the change of the orientation of the crimping.

[0050] In some embodiments, the feeding station comprises a transfer system adapted to pick up a stator from a conveyor and place it on the support at the feeding station.

[0051] This feature allows carrying out an automated insertion of the stator in the first operating station.

[0052] Preferably, said conveyor is placed outside the turntable.

[0053] This allows to facilitate the interaction of the machine with possible conveyors present in the plant where the machine is installed.

[0054] Advantageously, said machine comprises a reader device configured to read an identification element.

[0055] Said identification element is preferably a TAG+RFID.

[0056] Preferably, said identification element contains the information on the type of stator.

[0057] Preferably, said identification element contains the dimensional data of the stator.

[0058] In some embodiments, said reader device is configured to transmit at least to the welding station by means of the programmable control unit said information, read by the identification element.

[0059] Each of these characteristics contributes to adapting at least the welding station to the characteristics, in particular dimensional ones, of the stator and busbar and carrying out the welding in the correct positions by varying the position of said welding head based on the received dimensional data of the stator and busbar.

[0060] This also makes it possible to carry out a fully automated format change in cases where the external diameter of the stator does not vary. In any case, in cases where the format change is envisaged for the production of stators of different diameters, it will only be necessary to manually replace the laying and the picking gripper.

[0061] In some embodiments, the conveyor is provided with said identification element.

[0062] In this way, it is possible to have only one identification element that is rewritten each time upon the arrival of a new stator entering the machine. In some embodiments of the invention, the welding machine comprises a writing device configured to write on the identification element information relating to the welding carried out in said welding station.

[0063] This is particularly advantageous in the case where the identification element is physically associated with the stator as it also allows the welding information to be made available among the information identifying the stator.

[0064] In a second aspect, the technical problem of the invention is also solved and one or more of the objects are at least in part achieved by the invention by means of a welding method for welding terminals of a stator to respective seats of a busbar for the production of an electric motor by means of a welding head.

[0065] In some embodiments, said method comprises the step of positioning the stator on a movable support.

[0066] Preferably, said step of positioning the stator comprises removably constraining said stator with respect to said support.

[0067] In this way, the stator and support move integrally during the execution of the operating steps.

[0068] According to further preferred embodiments of the invention, said method comprises the step of positioning the movable support with the stator removably constrained thereto at a first station at which the busbar is assembled on the stator with said terminals being arranged in correspondence of the respective seats of the busbar.

[0069] Preferably, said method comprises the step of acquiring dimensional data relating to said stator and / or said busbar by means of a programmable control unit.

[0070] Said method comprises the step of positioning the mobile support with the stator assembled with the busbar and arranged thereon in correspondence with a second station.

[0071] Preferably, said method comprises the step of welding the terminals of a stator to respective seats of the busbar in correspondence with said second station preferably by rotating the stator around its axis of symmetry.

[0072] In some embodiments, the method comprises the step of carrying out said welding by moving a welding head along a vertical axis and at least along a horizontal axis towards / away from said stator, according to the dimensional data of the stator and / or of the busbar received by the welding station, by means of the programmable control unit, in such a way as to adapt the position of the welding head based on the dimensional data received.

[0073] Each of these features contributes to making it possible to create an operating method that allows the stator to be assembled to the busbar automatically reaching the plurality of welding points necessary to weld the terminals of the stator to the relative busbar.

[0074] In addition, thanks to the dimensional data related to said stator and / or said busbar received by the welding station, through the programmable control unit the method makes it possible to operate on stators and relative busbars of different type and size by performing an automatic format change.

[0075] Preferably, said method provides, after welding, a step of performing auxiliary assembly operations.

[0076] Preferably, the step of performing auxiliary assembly operations takes place in a third station operating downstream of the second station.

[0077] Thanks to this feature, the method allows to optimize the operating cycle by dividing the execution times of the steps on different operating stations, so that during the auxiliary assembly operations of a stator and busbar assembly, another stator and busbar assembly can be subjected to the welding step.

[0078] According to a preferred aspect, said method also provides for bringing the stator in correspondence with the operating stations by moving the supports according to a rotary motion around a central axis of symmetry. Preferably, the method provides for performing rotations in steps equal to a portion of circumference that is a function of the number of operating stations. This aspect of the method contributes to the possibility of performing the operating steps simultaneously by positioning a stator in each operating station.

[0079] According to an advantageous aspect, said method provides for rotating the stator around its axis of symmetry.

[0080] This facilitates and speeds up the relative positioning between the stator and the welding head.

[0081] According to an advantageous aspect, said method provides during the welding step, for the step of moving the welding head according to the third transverse axis perpendicular to said vertical axis and said horizontal axis, so as to crimp the seats of the busbar in a direction having a component in the transverse axis.

[0082] According to a preferred embodiment, said method provides for the step of detecting the information on the type of stator by reading an identification element, preferably a TAG+RFID, which contains the information on the type of stator.

[0083] Preferably, these are dimensional data.

[0084] Preferably, said method provides for the step of transmitting said information by means of the programmable control unit to at least the second operating station.

[0085] Each of these characteristics contributes to performing a method that makes it possible to carry out the welding in the correct positions according to the dimensional data acquired of the stator and busbar and allows to carry out a fully automated format change.

[0086] In some embodiments, the method provides, preferably downstream of said welding step, for the step of writing on the identification element information relating to the welding carried out.

[0087] Thanks to this aspect, the information on the welding carried out can be stored directly on the identification element. In particular, for resistance welding, information on the welding process relating to electrical resistance, supply voltage, transmitted electrical current, linear travel of the electrodes, crimping force (pressure) exerted during welding can be transmitted.

[0088] In this way, if the identification element is physically associated with the stator, said stator carries with it, and always makes available, information that identifies it, including that on welding.

[0089] Further preferred aspects of the machine and of the relative method subject-matter of the invention are also defined in the appended claims as well as in the following description.

[0090] The characteristics and advantages of the invention will become clearer from the detailed description of preferred embodiments thereof illustrated, by way of non-limiting example, with reference to the appended drawings wherein:

[0091] - Figure 1 is a perspective view, from the side of the finishing station of a welding machine according to the present invention;

[0092] - Figure 2 is a top view of the welding machine according to the present invention;

[0093] - Figure 3 is a perspective view, in detail, of a welding head and turntable of the welding machine of Figure 1;

[0094] - Figure 4 is a side view, in detail, of a transfer system of the feeding station of the welding machine according to the present invention;

[0095] - Figure 5 is a side view, from the side of the feeding station, of the welding machine according to the present invention;

[0096] - Figure 6a, 6b, 6c are perspective views, in detail, of a stator, of a busbar and stator and busbar assembled.

[0097] - Figure 7 is a schematic view of the electrodes of the welding head in an operating position.

[0098] Figure 8 is a schematic view of the electrodes of the welding head in an operating position in which they crimp the seat and the respective terminal allocated inside, with the respective mechanical deformation contextual to resistance welding.

[0099] With reference initially to Figure 1, a welding machine is indicated as a whole with the reference numeral 100.

[0100] The welding machine 100 is advantageously of the type adapted to weld terminals wl, w2, w3, w4, w5, w6, of a stator 201 to a busbar 202 for the production of an electric motor 200. It should be reminded that terminal means the aggregate group of conductive terminal wires.

[0101] The stator 201 advantageously has an axially symmetrical shape, generally substantially cylindrical, which develops around an axis of symmetry 203, as depicted in Figure 6a.

[0102] By way of example, Figure 6a depicts in detail a stator 201 comprising 6 terminals wl, w2, w3, w4, w5, w6, and Figure 6b depicts a busbar 202 with respective 6 seats wl', w2', w3', w4', w5', w6' configured to engage with said terminals wl, w2, w3, w4, w5, w6, to carry out the assembly of Figure 6c.

[0103] For this purpose, the machine 100 may comprise a plurality of operating stations 11, 12, 13, 14 as can be observed for example from Figure 2. According to a preferred aspect of the invention, the machine 100 comprises at least one movable support 21, 22, 23, 24 configured to receive and hold a stator 201 and bring it in correspondence with each operating station 11, 12, 13, 14 of the machine 100.

[0104] Preferably, the support 21, 22, 23, 24 that holds the stator 201 defines a removable type constraint therewith.

[0105] For this purpose, each support 21, 22, 23, 24, may comprise locking elements 25 that engage on the stator 201 to hold it integrally, as depicted in Figure 3. Said locking elements 25 can be movable between an engagement position and a disengagement position. Preferably said locking elements 25 can be configured to translate towards / away from each other to engage / disengage with the stator 201 positioned on the support 21, 22, 23, 24.

[0106] Said translation towards / away from the locking elements 25 preferably takes place in a radial direction with respect to the axis of symmetry 203 of the stator positioned on the support 21, 22, 23, 24.

[0107] In preferred embodiments, the welding machine 100 comprises a turntable 10 on which the at least one support 21, 22, 23, 24 is installed. The turntable 10 is configured to rotate about a central axis of symmetry

[0108] I.

[0109] The turntable 10, during rotation, brings each support 21, 22, 23, 24 in correspondence with each operating station 11, 12, 13, 14.

[0110] According to one aspect of the invention, the turntable 10 comprises as many supports 21, 22, 23, 24 as the number of the operating stations 11, 12, 13, 14.

[0111] Preferably said supports 21, 22, 23, 24 are arranged equidistant from each other on said turntable 10 along a circumference coaxial to the axis of symmetry I.

[0112] The turntable 10 can perform step rotations, in which at each step the supports 21, 22, 23, 24 pass simultaneously from one operating station

[0113] II, 12, 13, 14 to the next.

[0114] As described, the movable support 21, 22, 23, 24 receives a stator 201 and brings it in correspondence with each operating station 11, 12, 13, 14. These operating stations 11, 12, 13, 14 may comprise at least one assembly station 12 and a welding station 13, the characteristics of which will be described further below.

[0115] In the assembly station 12 the busbar 202 is assembled on the stator 201. Preferably, said operation provides for aligning the terminals wl, w2, w3, w4, w5, w6, of the stator 201 with the corresponding seats wl', w2', w3', w4', w5', w6'. The operation can be carried out manually by an operator, or automatically by automatic means, not depicted in the figures.

[0116] Some embodiments provide that, following the operation of inserting the terminals wl, w2, w3, w4, w5, w6 in the corresponding seats wl', w2', w3', w4', w5', w6', there is a recession of the excess sections of the terminals wl, w2, w3, w4, w5, w6 so that the latter do not protrude excessively from the respective seats wl', w2', w3', w4', w5', w6' of the busbar 202 to which they must be welded later.

[0117] In the embodiments in which the assembly station 12 is configured to be used by an operator, said assembly station may advantageously comprise a graphical interface device 41 comprising specific instructions for the operator based on the product to be made. Such a graphical interface device 41 (Human-Machine Interface) is preferably a monitor or screen.

[0118] Some embodiments provide that the assembly station 12 further comprises a busbar 16 magazine near the turntable 10. This magazine 16 may house one or more types of busbars 202. In this way, the operator or alternative automatic device (e.g. a robotic arm) will be able to efficiently pick up the busbar 202 corresponding to the type of stator 201 being produced. In cases where the operator is in charge of the assembly operations of the busbar 202, he / she may advantageously verify through the graphical interface device 41 the location of the type of busbar 202 to be picked up in the magazine 16, as well as the precautions necessary to carry out a correct assembly of said busbar 202.

[0119] The welding station 13 is advantageously configured to weld the terminals wl, w2, w3, w4, w5, w6 of the stator 201 to the busbar 202, in particular to the corresponding seats wl', w2', w3', w4', w5', w6'.

[0120] In preferred embodiments, the welding station 13 comprises a welding head 130 configured to weld the terminals of the stator 201 to the busbar 202.

[0121] The operating stations 11, 12, 13, 14 may further comprise a feeding station 11 upstream of the assembly station 12.

[0122] Said feeding station 11 preferably comprises a transfer system 110 adapted to pick up a stator 200 and place it on the support 21, 22, 23, 24 at the feeding station 11.

[0123] As depicted in Figure 4, the transfer system 110 can pick up the stator 201 from a conveyor 15.

[0124] Advantageously, the conveyor 15 can be placed outside the turntable 10. Figures 1 and 2 depict a possible embodiment, not limiting, in which the conveyor 15 is linear and arranged parallel to a direction tangent to the turntable 10.

[0125] The conveyor 15 may comprise a pallet 151 movable along a longitudinal axis of the conveyor 15 and configured to support a stator 201 and bring it in correspondence with the transfer system 110. Preferably the transfer system 110 comprises a gripping head 111 in turn comprising a plurality of gripping elements 115 configured to engage / disengage with the stator 201.

[0126] The gripping elements 115, as depicted in Figure 4, can be configured to translate towards / away from each other and engage / disengage with the stator 201.

[0127] The translation towards / away from the gripping elements 115 preferably takes place in a radial direction with respect to the axis of symmetry 203 of the stator 201 to be picked up.

[0128] Optionally, the gripping head 111 can be configured to rotate around a vertical axis of rotation, coinciding with the axis of symmetry 203 of the gripping stator 201. In this way it is possible to orient the stator 201 before placing it in the feeding station 11.

[0129] Figure 4 depicts a transfer system 110 of the Cartesian type, which comprises at least one translator 112 and a lifter 113 for moving the gripping head 111 between the conveyor 15 and the support 21, 22, 23, 24 located at the feeding station 11.

[0130] Preferably, the translator 112 and / or the lifter 113 each move along a linear trajectory.

[0131] The translator 112 and / or the lifter 113 can be activated by means of various type such as an electric motor, or pneumatic piston, etc.

[0132] According to a preferred aspect, the operating stations 11, 12, 13, 14 further comprise a finishing station 14 downstream of the welding station

[0133] 13.

[0134] Said finishing station 14 allows the stator 201 and busbar 202, once welded, to perform auxiliary assemblies on the stator 201, wait for the weld to cool or carry out control actions of the visual type.

[0135] Note that in the embodiment depicted in the figures, the machine 100 comprises a support 21, 22, 23, 24 for each operating station 11, 12, 13, Therefore, the waiting in the finishing station 14 does not affect the production rate, as at the same time the machine can perform operations in the other operating stations 11, 12, 13.

[0136] The finishing station 14 can also be used to carry out a verification of the correct assembly between stator 201 and busbar 202, by means of vision instruments, or by means of the intervention of the operator.

[0137] In general, it should be noted that a possible embodiment of the welding machine 100 is depicted in the figures, which comprises four operating stations 11, 12, 13, 14, which, as previously illustrated, in sequence are respectively a feeding station 11, an assembly station 12, a welding station 13 and a finishing station 14.

[0138] Furthermore, the machine 100 shown in the figures comprises four supports 21, 22, 23, 24. Consequently, in such embodiments the turntable 10 can advantageously perform rotations in 90° steps with which it transfers each support 21, 22, 23, 24 to the next operating station 11, 12, 13, 14.

[0139] After the finishing station 14, the machine 100 may comprise one or more accumulation stations, not depicted in the figures, to create a buffer adapted to compensate for any stops of the upstream operating stations 11, 12, 13.

[0140] Furthermore, after the finishing station 14, the machine 100 may comprise an unloading station.

[0141] The unloading station may also coincide with the feeding station 11, as in the example illustrated in the figures.

[0142] Thanks to this solution a 100 machine with a very compact layout is obtained.

[0143] In fact, after welding and auxiliary assembly operations, the machine 100 depicted in the figures, is configured to rotate the table 10 and bring the support on which the stator 201 with busbar 202 is positioned, from the finishing station 14, to the feeding station 11. The stator 201 welded with the busbar 202, can then be picked up by means of the transfer system 110, from the feeding station 11 and transferred to the outside of the machine 100.

[0144] Preferably the stator 201, welded with the busbar 202, is placed on the conveyor 15, in particular on the pallet 151.

[0145] At this point, the stator 201 welded with the busbar 202 is evacuated and a new stator 201 to be assembled is positioned on the conveyor 15 in particular on the pallet 151 and introduced into the feeding station 11, by means of the transfer system 110.

[0146] This is just one of the possible embodiments of the machine 100 that can also comprise more than one operating station 11, 12, 13, 14 for each type, allowing machines 100 to be made with greater production rates.

[0147] According to a preferred aspect, the machine 100 further comprises a programmable control unit 40 communicating at least with said welding station 13.

[0148] Advantageously, the programmable control unit 40 communicates with one or more of the other operating stations 11, 12, 14 and preferably also with the turntable 10.

[0149] Preferably, the welding station 13 is also configured to receive dimensional data related to the stator 201 and / or the busbar 202 from said programmable control unit 40.

[0150] In preferred embodiments, depending on the received dimensional data of the stator 201 and busbar 202, the welding station 13 is also configured to move the welding head 130 along a vertical axis Z and at least along a horizontal axis X.

[0151] In this way all the welding points can be reached.

[0152] In the embodiments where the assembly station 12 comprises a graphical interface device 41, such graphical interface device 41 may be suitably connected to the programmable control unit 40.

[0153] The welding points are at the seats wl', w2', w3', w4', w5', w6' of the busbar 202 where the terminals wl, w2, w3, w4, w5, w6, of the stator 201 engage. Figure 6b depicts a preferred embodiment of the busbar 202, wherein each seat wl', w2', w3', w4', w5', w6' comprises a through cavity for receiving therein a respective terminal wl, w2, w3, w4, w5, w6.

[0154] Preferably, the welding head 130 is configured to weld along an axis parallel to the horizontal axis X at the stator 201 and busbar 202 welding points.

[0155] In fact, the welding points are preferably at the lateral surface of the seats wl', w2', w3', w4', w5', w6' of the busbar 202 from which the terminals wl, w2, w3, w4, w5, w6, of the stator 201 actually emerge.

[0156] The welding points are generally coplanar, arranged on the same horizontal plane.

[0157] The displacement in vertical axis Z allows the welding head 130 to be positioned on the horizontal plane on which the welding points are located. The displacement in horizontal axis X allows the welding head 130 to reach all the coplanar welding points.

[0158] The welding station 13 may comprise a horizontal movement device 134, and a vertical movement device 135 which are configured to translate the welding head 130 respectively along the horizontal axis X and along the vertical axis Z. The welding station 13 may comprise a transverse movement device 136 configured to translate along the transverse axis Y perpendicular to the horizontal X and vertical Z axis.

[0159] According to an optional aspect, each support 21, 22, 23, 24 is rotatably fixed to the turntable 10.

[0160] Furthermore, the welding machine 100 may comprise, as depicted in Figure 3, a rotation member 131 arranged in correspondence of the welding station 13 and configured to rotate the support 21, 22, 23, 24 around an axis 132 of the rotation member 131.

[0161] This permits that the relative position between the stator 201 with said busbar 202 and the welding head 130 can be changed in order to weld said stator 201 and said busbar 202 in a plurality of welding points thereof. Preferably said axis 132 of the rotation member coincides with the axis of symmetry 203 of the stator 201. Preferably, the horizontal axis X of translation of the welding head 130 is radial with respect to the rotation support 21, 22, 23, 24 arranged in correspondence of the welding station 13, wherein the horizontal axis X passes through the axis 132 of the rotation member.

[0162] By combining the rotation of the stator 201 and busbar 202, by means of the rotation member 131 for the rotation of the support 21, 22, 23, 24, with the translation of the welding head 130 along the radial horizontal axis X passing through the axis 132, it is possible to reach all the coplanar welding points.

[0163] The rotation member 131, depicted in the figure, is driven in rotation by an electric motor 133, but said representation is only a non-limiting example.

[0164] Preferably, the motor 133 is controlled by the programmable control unit 40.

[0165] Therefore, by means of the programmable control unit 40, the rotation of the support 21, 22, 23, 24 and the horizontal X and vertical Z translation of the welding head 130 are combined to reach all the welding points.

[0166] An advantageous embodiment of the invention provides that said welding machine 100 further comprises a reader device 17 configured to read an identification element, preferably a TAG+RFID.

[0167] Said identification element, not depicted in the figures, may contain information on the type of stator 201, preferably dimensional data.

[0168] The reader device 17 is preferably configured to transmit the information at least to the welding station 13, by means of the programmable control unit 40.

[0169] Therefore, the dimensional data received by the welding station 13, to move said welding head 130, can be information provided to the programmable control unit 40 by the reader device 17, which detects them from the identification element.

[0170] In the event that the reader device 17 is not present, the information can be provided to the programmable control unit 40 by the operator him- / herself who enters the dimensional data, for example, through an editable interface of said programmable control unit 40.

[0171] Alternatively, said information can be entered into an archive of said programmable control unit 40, as predefined recipes or selections, which can be activated by means of special activation elements.

[0172] An optional aspect provides that the identification element is provided on the conveyor 15.

[0173] In this case the identification element must be rewritten each time the stator 201 is picked up by the transfer system 110 and a new stator 201 is positioned on the conveyor 15.

[0174] Advantageously, the identification element can be integral with the mobile pallet 151 on which the stator 201 is positioned.

[0175] In the event that the conveyor 15 is provided with the identification element, the reader device 17 can be arranged in correspondence with the feeding station 11.

[0176] An alternative embodiment may provide that the identification element is directly arranged on the stator 201. It is evident that in this way the stator 201 carries with it all the information necessary for its identification.

[0177] In this case, the reader device 17 can be arranged in correspondence with the feeding station 11, or in correspondence with the assembly station 12 or the welding station 13, or in any case in any position where it can be read before welding.

[0178] The welding machine 100 may also comprise a writing device 18 configured to write on the identification element information relating to the welding carried out in said welding station 13. This type of operation can be done in various ways by associating this information with the TAG + RFID. Alternatively, in cases where the stator has been marked with a DATAMATRIX code (QR code) it will be possible to associate this welding information with the DATAMATRIX code.

[0179] This solution is particularly suitable in the event that the identification element is directly installed on the stator 201, because it allows all the identification information, including those related to welding, to be kept associated with the stator 201.

[0180] The method for welding terminals wl, w2, w3, w4, w5, w6 of a stator 201 to a busbar 202 for the production of an electric motor 200 is also an object of the invention.

[0181] The method is advantageously performed by means of the welding machine 100 of the present invention.

[0182] The method initially provides for the step of arranging the stator 201 on a movable support 21, 22, 23, 24, removably constraining the stator 201 respect to the support 21, 22, 23, 24.

[0183] The movable support 21, 22, 23, 24 with the stator 201 removably constrained thereto is then positioned at a first station 12 at which the busbar 202 is assembled on the stator 201 with said terminals wl, w2, w3, w4, w5, w6 being arranged in correspondence of the respective seats wl', w2', w3', w4', w5', w6' of the busbar 202.

[0184] Dimensional data relating to the stator 201 and / or the busbar 202 can also be received by means of the programmable control unit 40.

[0185] The movable support 21, 22, 23, 24 with the stator 201 and the busbar 202 arranged thereon are positioned in correspondence with a second station 13 at which the terminals of the stator 201 are welded to the busbar 202.

[0186] The welding step advantageously takes place by moving the welding head 130 along a vertical axis Z and at least along a horizontal axis X towards / away from said stator 201 according to the dimensional data of the stator 201 and / or of the busbar 202 received from the programmable control unit 40, to adapt the position of the welding head 130 according to the received dimensional data.

[0187] The positioning of the busbar 202 on the stator 201, at the first station 12, can be carried out manually by the operator. Preferably the operator can further arrange the terminals wl, w2, w3, w4, w5, w6 in the seats wl', w2', w3', w4', w5', w6', cut the excess wires and declare the end of the manual processing, by means of an editable interface of the programmable control unit.

[0188] The positioning of the busbar and the other operations described above can also be performed by automated means.

[0189] Preferably, the method further provides for bringing the stator 201 in correspondence with the operating stations 11, 12, 13, 14 by moving the supports 21, 22, 23, 24 according to a rotary motion around a central axis of symmetry I, preferably performing rotations in steps equal to a portion of circumference that is a function of the number of operating stations 11, 12, 13, 14.

[0190] In some embodiments, the method may provide, during the welding step, for rotating the stator 201 around its axis of symmetry 203.

[0191] Preferably, it provides for rotating the stator 201 in combination with an adjustment of the position of the welding head 130 as a function of information provided by the programmable control unit 40.

[0192] By rotating the stator 201 and moving the welding head 130 along a vertical axis Z and a horizontal axis X, the method can thus allow reaching all the welding points provided for fixing the stator 201 to the busbar 202. Preferably, as previously illustrated, the horizontal axis X is directed radially with respect to the axis of rotation of the stator 201 which coincides with its axis of symmetry 203.

[0193] According to a preferred aspect, a step of performing auxiliary assembly operations may be provided, after the welding step, preferably in the third operating station 14 downstream of the second station 13.

[0194] After the auxiliary assembly operations, the stators 201 welded with the busbar 202 can be advantageously accumulated, to create a buffer adapted to compensate for any stops of the upstream operating stations 12, 13, 14.

[0195] Generally, after the step of performing auxiliary assembly and / or accumulation operations, the stator 201 with welded busbar 202 can be unloaded from the machine 100 to continue with other machining on other machines. According to a preferred aspect, the unloading step takes place by returning the stator 201 with the welded busbar 202 in the feeding station 11, i.e. the station through which the stator 201 to be welded was initially introduced, located upstream of the first station 12.

[0196] A particularly advantageous aspect of the method consists in the step of detecting the information relating to the type of stator 201 by reading an identification element, preferably a TAG+RFID, which contains the information on the type of stator 201, preferably dimensional.

[0197] Preferably said information, once detected, is transmitted to the programmable control unit 40 and advantageously transmitted, by means of the programmable control unit 40, to at least the second operating station 13 or to one or more other operating stations.

[0198] Optionally, the aforementioned information can be detected by reading an identification element associated with means 15 adapted to introduce the stator 201 into the machine 100 or associated with the stator 201 itself.

[0199] The information on the type of stator 201 can be detected by reading the identification element before performing the welding step.

[0200] Downstream of said welding step, there may also be foreseen the step of writing on the identification element information relating to the welding carried out.

[0201] The invention thus achieves the proposed objects, also achieving numerous advantages with respect to the prior art of reference, including the possibility of welding stators and busbars in particular by making a plurality of welds arranged on a horizontal plane at a variable distance from the axis of symmetry of the stator and at a variable height and with the possibility of automatically adapting to different types and sizes of stator and busbar.

Claims

CLAIMS1. Welding machine (100) for welding terminals (wl, w2, w3, w4, w5, w6) of a stator (201) to respective seats (wl', w2', w3', w4', w5', w6') of a busbar (202) for the production of an electric motor (200), said machine (100) comprising- a plurality of operating stations (11, 12, 13, 14) and- at least one movable support (21, 22, 23, 24) configured to hold the stator (201) and to position it within each of the operating stations (11, 12, 13, 14) of the welding machine (100),Wherein said operating stations (11, 12, 13, 14) comprise at least: an assembly station (12) configured to assemble the busbar (202) onto the stator (201), aligning said terminals (wl, w2, w3, w4, w5, w6) with the corresponding seats (wl', w2', w3', w4', w5', w6'), a welding station (13) comprising a welding head (130) configured to weld the terminals (wl, w2, w3, w4, w5, w6) of the stator (201) to the seats (wl', w2', w3', w4', w5', w6') of the busbar (202), wherein said machine (100) further comprises:- a rotation member (131) arranged in correspondence of said welding station (13) and configured to rotate said movable support (21, 22, 23, 24) about the axis (132) of said rotation member (131); and- a programmable control unit (40) in communication with at least said welding station (13) and configured to receive dimensional data related to said stator (201) and / or said busbar (202); said welding station (13) being configured to move said welding head (130) along at least one vertical axis (Z) and at least one horizontal axis (X) based on the received dimensional data.

2. The welding machine (100) according to claim 1, characterized in that said welding head (130) comprises at least one welding electrode (137) and a ground electrode (138), said welding head (130) being configured to reciprocally move the electrodes (137, 138) between an open position, in which both electrodes (137, 138)are external to the seats (wl', w2', w3', w4', w5', w6') of the busbar (202) and a closed position in which at least the welding electrode (137) engages one of the seats (wl', w2', w3', w4', w5', w6') of the busbar (202) by exerting a crimping pressure, wherein said welding head (130) is configured to apply an electric welding current to the crimped seat (wl', w2', w3', w4', w5', w6').

3. The welding machine (100) according to claim 2, characterized in that said welding station (13) is further configured to translate said welding head (130) along a third transverse axis (Y) perpendicular to said vertical axis (Z) and said horizontal axis (X), so as to crimp the seats (wl', w2', w3', w4', w5', w6') of the busbar (202) in a direction having a component in the transverse axis (Y).

4. The welding machine (100) according to any of the preceding claims, characterized in that the operating stations (11, 12, 13, 14) further comprise a feeding station (11) upstream of the assembly station (12) and a finishing station (14) downstream of the welding station (13).

5. The welding machine (100) according to any of the preceding claims, characterized in that it comprises a turntable (10) on which the at least one support (21, 22, 23, 24) is installed, said turntable (10) being configured to rotate around a central axis of symmetry (I) to bring said at least one support (21, 22, 23, 24) in correspondence with each operating station (11, 12, 13, 14).

6. The welding machine (100) according to claim 5, characterized in that the turntable (10) comprises as many supports (21, 22, 23, 24) installed thereon as the number of operating stations (11, 12, 13, 14) of the welding machine, wherein said supports (21, 22, 23, 24) are preferably arranged equidistant from each other on said turntable (10) along a circumference coaxial to the axis of symmetry (I).

7. The welding machine (100) according to claim 5 or 6, characterized in that each support (21, 22, 23, 24) is fixed in a rotatable mannerto the turntable (10).

8. The welding machine (100) according to any of claims 5 to 7, characterized in that the feeding station (11) comprises a transfer system (110) for picking up a stator (200) from a conveyor (15) located external with respect to the turntable (10), and placing it on the support (21, 22, 23, 24) at the feeding operating station (11).

9. The welding machine (100) according to any of the preceding claims, characterized in that it further comprises a reader device (17) configured to read an identification element, preferably a TAG+RFID, which contains information on the type of stator (201), preferably dimensional information, and in that said reader device (17) is configured to transmit said information at least to the welding operating station (13) by means of the programmable control unit (40).

10. The welding machine (100) according to claim 9, characterized in that said conveyor (15) is provided with said identification element.

11. The welding machine (100) according to claim 9 or 10, characterized in that it further comprises a writing device (18) configured to write on the identification element information relating to the welding operation carried out in said welding operating station (13).

12. Method for welding terminals (wl, w2, w3, w4, w5, w6) of a stator(201) to respective seats (wl', w2', w3', w4', w5', w6') of a busbar(202) for the production of an electric motor (200) by means of a welding head (130), said method comprising the steps of:- arranging the stator (201) on a movable support (21, 22, 23, 24), wherein said step of arranging comprises removably constraining said stator (201) to said support (21, 22, 23, 24),- positioning the movable support (21, 22, 23, 24) with the stator (201) removably constrained thereto at a first station (12) at which the busbar (202) is assembled on the stator (201) with said terminals (wl, w2, w3, w4, w5, w6) being arranged incorrespondence of the respective seats (wl', w2', w3', w4', w5', w6') of the busbar (202),- acquiring dimensional information relating to said stator (201) and / or said busbar (202) by means of a programmable control unit (40);- positioning the mobile support (21, 22, 23, 24) with the stator (201) assembled with the busbar (202) and arranged thereon in correspondence with a second station (13);- welding each of the terminals (wl, w2, w3, w4, w5, w6) of the stator (201) to the respective seat (wl', w2', w3', w4', w5', w6') of the busbar (202) in correspondence with said second station (13) by rotating the stator (201) around its axis of symmetry (203) and by moving the welding head (130) in a vertical axis (Z) and at least in a horizontal axis (X) towards / away from said stator (201) according to the dimensional information of the stator (201) and / or of the busbar (202) acquired by the programmable control unit (40), to adapt the position of the welding head (130) according to the acquired dimensional information.

13. The method according to claim 12, further comprising a step of performing auxiliary assembly operations, after welding, preferably in a third station (14) operating downstream of the second station (13).

14. The method according to claim 12 or 13, wherein said method comprises bringing the stator (201) in correspondence with the operating stations (11, 12, 13, 14) by moving the supports (21, 22, 23, 24) according to a rotary motion around a central axis of symmetry (I), preferably performing rotations in steps equal to a portion of circumference that is a function of the number of operating stations (11, 12, 13, 14).

15. The method according to anyone of claims 12 to 14, comprising, during the step of welding, a step of moving the welding head (130) along a third transverse axis (Y) perpendicular to said vertical axis(Z) and said horizontal axis (X), so as to crimp the seats (wl', w2', w3', w4', w5', w6') of the busbar (202) in a direction having a component in the transverse axis (Y).

16. The method according to anyone of claims 12 to 15, comprising a step of detecting information on the type of stator (201) by reading an identification element, preferably a TAG+RFID, which contains the information on the type of stator (201), preferably dimensional information, and a step of transmitting said information by means of the programmable control unit (40) to at least the second operating station (13).

17. The method according to anyone of claims 13 to 16, comprising, downstream of said welding step, a step of writing information relating to the already carried out welding operation on the identification element.

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