IT202000013009A1 - SCREWING APPARATUS - Google Patents

Description

DESCRIPTION

[0001] The present invention relates to a screwing apparatus for a plant for the automated screwing of screws on mechanical pieces. Furthermore, the same system for the automated tightening of screws on mechanical pieces comprising said tightening apparatus ? object of the present invention.

[0002] In particular, the present invention relates to the industrial mechanics sector, with particular reference to screw tightening apparatuses suitable for assembling screws in an automated manner. With particular reference to known screwing apparatuses, it is emphasized that these perform said operations with self-tapping trefoil screws, preferably on aluminum or zamak mechanical parts.

[0003] Known screwing apparatuses include specific screwing devices specifically designed to engage and guide the screws in rotation as well as other specific handling devices purposely provided for carrying out the movements which accompany said screwing devices along the screwing axis; in this way, the coordinated movement of said devices involves screwing the screw to the mechanical component.

[0004] Typical problem of known tightening apparatuses? linked to the modalities? in accordance with which said operations are performed: in some cases, in fact, these are complex to control and it happens that they end before the completion of the tightening, or do they continue even when the screw? already arrived at bat; There? involves problems and even breakages, obviously unwanted, of the screw and/or of the mechanical component on which the screw is attached? screwed.

[0005] A further problem, which occurs particularly in situations in which the screws also perform the tapping of the mechanical component, is linked to the modalities? in which ? the transmission torque necessary to carry out said tapping is transmitted to the screw; in known screwing apparatuses said transmission torque ? typically entrusted to a pneumatic system that preloads the? tightening tool on the screw to transmit the torque, and therefore usually? oversized. In addition, some known screwing apparatuses undergo passively, and in some cases even break, the action of said torque deriving from the thrust.

[0006] And? therefore the need to make available a tightening assembly which performs the tightening operations solving the aforementioned problems is strongly felt.

[0007] The purpose of the present invention? that of supplying a screwing apparatus suitable for carrying out screwing and in particular tapping operations efficiently and reliably over time, obviating any possible that breakages or ?seizings? of the threads, on the screws and/or on the mechanical parts on which these screws are mounted, and/or on the tightening apparatus itself.

[0008] This purpose? achieved by means of the screwing apparatus claimed in claim 1. Furthermore, this aim is also achieved by the plant for automated tightening comprising said tightening apparatus according to claim 16. The dependent claims seek protection for further characteristics and entail further technical advantages.

[0009] Further characteristics and advantages of the invention will appear from the following description of preferred embodiments thereof, given by way of non-limiting example, with reference to the attached figures in which:

[00010] ? the figures 1? and 1? show two perspective views of the automated screwing system according to a preferred embodiment;

[00011] ? figures 1a and 1b show two side views of the plant for automated tightening according to the present invention, respectively in which the tightening apparatus is configured in a lower operating configuration and ? configured in a higher operating configuration, i.e. two distinct configurations in which to perform the tightening operations at different heights;

[00012] ? figures 2a and 2b show two perspective views of the tightening apparatus object of the present invention, in a preferred embodiment;

[00013] ? figures 3 and 3? respectively show a side view and a front view of the tightening apparatus shown in figures 2a and 2b, configured in a lower operating configuration, with the tightening device raised, in the starting position;

[00014] ? figures 4 and 4? respectively represent a side view and a front view of the tightening apparatus shown in figures 2a and 2b, configured in a lower operating configuration, with the tightening device lowered, in the tightening position;

[00015] ? figures 5 and 5? respectively represent a side view and a front view of the tightening apparatus shown in figures 2a and 2b, configured in an upper operating configuration, with the tightening device raised, in the starting position;

[00016] ? figures 6 and 6? respectively represent a side view and a front view of the tightening apparatus shown in figures 2a and 2b, configured in an upper operating configuration, with the tightening device lowered, in the tightening position;

[00017] ? figure 7a ? a sectional view of the tightening apparatus of Figure 4;

[00018] ? figure 7b ? a sectional view of the tightening apparatus shown in figure 5.

[00019] With reference to the attached figures, with the number 1 ? indicated a screwing apparatus in accordance with the present invention.

[00020] In particular, the tightening apparatus 1? suitable for being part of an automated screwing system 900, which in turn is the object of the present invention.

[00021] Said tightening system 900 comprises an industrial robot 910 and a support apparatus 920. As shown by way of example, in the attached images, the industrial robot 910 ? a manipulator with a plurality? of segments and a working head. The present invention is not limited to particular embodiments of the support apparatus 920. The present invention is not limited to particular embodiments of the support apparatus 920.

[00022] Preferably, the support apparatus 920 is mobile and controllable in a plurality? of spatial locations. Preferably, the 910 industrial robot ? suitable to operate in said different spatial positions.

[00023] In other words, support apparatus 920 and industrial robot 1 allow the handling and execution of the operations described below in a variety of ways. of locations. That is to say that the 900? screwing system? suitable for performing the operations described below in a multiplicity? of positions, guaranteeing high flexibility, even on mechanical pieces with particular shapes.

[00024] In accordance with the present invention, the screwing apparatus 1? mountable on the support apparatus 920 and is, as extensively described below, operatively engageable by the industrial robot 910.

[00025] In accordance with the present invention, with screws we refer to ?classical? screws, but also to ?trefoil? suitable for performing a tapping operation of the mechanical piece during its insertion operations.

[00026] Preferably, in the present invention, the mechanical pieces on which said screwing (and tapping) operations are performed are aluminum or zamak pieces, plastically modifiable by the screw during the screwing operations.

[00027] According to the present invention, the screwing apparatus 1 extends along a Z-Z axis.

[00028] Preferably, said Z-Z axis corresponds to the screwing axis.

[00029] In accordance with the present invention, the rotational movements described below of the screw and other components occur around said Z-Z axis. In addition, in accordance with the present invention, the described axial movements occur along or parallel to said Z-Z axis.

[00030] In accordance with the present invention, the screwing apparatus 1 comprises a screwing device 2 specially adapted to rotate a screw, a screw feeding device 3 suitable to supply screws to the screwing device 2, a support structure 4 for supporting said devices, and further handling devices 5.

[00031] In particular, the screwing ? obtained by means of the screwing device 2, where some of its components are driven in rotation and some of its components are driven in axial translation.

[00032] In particular, the handling devices 5 are suitable for allowing the handling and axial positioning of some certain components, while the aforementioned axial handling of the components of the screwing device 2, ?, as described below, obtained by the 910 industrial robot.

[00033] According to the present invention, the screwing device 2 comprises, along the Z-Z axis, a screw gripper 20 for supporting and tightening a screw, a screwing tool 21 suitable for engaging a screw and a spindle member 22 suitable for controlling the rotation of the screwing tool 21.

[00034] In accordance with the present invention, the screw gripper 20 ? positioned distally, along the Z-Z axis, from the spindle member 22.

[00035] Preferably, the screw gripper 20 ? operatively connected with the screwing tool 21 during the screwing operations. While during the other operations, for example the feeding operations of a new screw, the screwing tool 21 is? axially spaced from the screw collet 20.

[00036] In particular, in fact, as fully described below, the screwing tool 21 and the spindle member 22 can be moved axially with respect to the screw collet 20.

[00037] In accordance with a preferred embodiment, the screwing tool 21 is essentially a rod element that extends along the Z-Z axis.

[00038] In accordance with a preferred embodiment, the mandrel member 22 is an electronic screwdriver.

[00039] In accordance with a preferred embodiment, the mandrel member 22 is suitable for driving the rotation of the screwing tool 21 (engaged to a screw) at a speed? function of the type of screw and the type, and pitch, of the thread of said screw.

[00040] In accordance with the present invention, the screw feeding device 3 ? suitable for supplying screws to the screwdriving device 2, in particular to the screw clamp 20.

[00041] Preferably, in fact, the screw feeding device 3 comprises a tubular element 30 whose end? ? connected to the screw gripper 20. Through said tubular element 30, the screw feeding device 3, in an automated manner, supplies a screw to the screw gripper 20 when necessary, for example once the screwing operations of a previous screw have been completed.

[00042] In accordance with the present invention, the support structure 4 comprises a plurality of of distinct components.

[00043] In particular, in fact, the support structure 4 comprises a base frame 40 which can be mounted integrally with the support apparatus 920.

[00044] Preferably said base frame 40 ? consisting of one or more metal components.

[00045] Basically, the base frame 40 serves as the base of the screwing apparatus 1.

[00046] In accordance with a preferred embodiment, the base frame 40 extends parallel to the Z-Z axis.

[00047] Furthermore, according to the present invention, the support structure 4 comprises a gripper plate 41, or lower plate, on which mounted the screw collet 20 and a control plate 42, or higher, for supporting the screwing tool 21 and the spindle member 22.

[00048] Preferably, the gripper plate 41 extends substantially orthogonally from the Z-Z axis.

[00049] Preferably, the drive plate 42 extends substantially orthogonally from the Z-Z axis.

[00050] In accordance with a preferred embodiment, the gripper plate 41 and the control plate 42 are operatively connected and supported by the base frame 40.

[00051] In accordance with the present invention, the screwing apparatus 1 comprises specific movement devices 5 mounted on the support structure 4 and operatively connected with the base frame 40, with the gripper plate 41 and with the control plate 42 .

[00052] Preferably, by means of the movement devices 5, the gripper plate 41 and the control plate 42 can be positioned in preferred axial positions along the Z-Z axis.

[00053] In other words, the handling devices 5 allow the handling and relative positioning of the gripper plate 41 and the control plate 42 on the base frame 40.

[00054] According to a preferred embodiment, the handling devices 5 comprise at least one guide element 50 positioned on the base frame 40 extending parallel to the Z-Z axis.

[00055] Preferably, the guide element 50 comprises one or more parallel rails.

[00056] In accordance with said embodiment, the handling devices 5 also comprise a first shoe 51 engaged on the gripper plate 41 suitable for sliding on said at least one guide element 50 and a second shoe 52 engaged on the control plate 42 suitable to slide on said at least one guide element 50.

[00057] In accordance with a preferred embodiment, the first shoe 51 and second shoe 52 are specially shaped to engage said guide element 50 in sliding.

[00058] In a preferred embodiment, the handling devices 5 comprise a single guide element 50 and the first shoe 51 and the second shoe 52 both slide on said guide element 5.

[00059] Furthermore, in accordance with a preferred embodiment, the movement devices 5 comprise a pneumatic brake member 53 which can be controlled in a stop position so as to block the gripper plate 41 axially along the Z-Z axis.

[00060] According to a preferred embodiment, said pneumatic brake member 53? suitable to be stopped during the execution of the tightening operations.

[00061] In accordance with a preferred embodiment, the pneumatic brake member 53 is which can be controlled pneumatically and comprises jaw means suitable for being clamped on the guide element 50.

[00062] Furthermore, according to a preferred embodiment, the movement devices 5 comprise a first piston group 54 engaged with the gripper plate 41 and with the control plate 42.

[00063] Preferably, the first piston group 54 has one end fixed to the clamp plate 41 and the other end? fixed to the control plate 42.

[00064] In particular, the first piston group 54 ? pneumatically controllable.

[00065] According to a preferred embodiment, the first piston group 54 is controllable pneumatically in the block, i.e. in a mode? wherein the gripper plate 41 and the drive plate 42 are mutually integrally connected. Preferably, with the first piston group 54 in block, the gripper plate 41 and the control plate 42 can be moved simultaneously.

[00066] Furthermore, the first piston group 54 ? which can be controlled pneumatically in release in such a way as to allow the axial movement of the control plate 42 with respect to the gripper plate 41.

[00067] In accordance with a preferred embodiment, in the en bloc configuration, the first piston group 54? extended.

[00068] In accordance with a variant embodiment, the first piston group 54 is suitable for commanding a relative axial movement between the gripper plate 41 and the control plate 42 to return to the extended a configuration.

[00069] In accordance with a preferred embodiment, the handling devices 5 also comprise a second piston group 55 engaged to the base frame 40 and to the control plate 42 suitable for cushioning the action of the weight force of the control plate 42 and of the components housed on it.

[00070] Preferably, the second piston group 55 is committed to the base frame 40 and has one extremity? engaged to the drive plate 42.

[00071] In accordance with a preferred embodiment, the second piston group 55 compensates for the action of the weight force on the control plate 42, and on all the components connected to it.

[00072]. Preferably, the second piston group 55 is pneumatically controlled.

[00073] In accordance with a variant embodiment, the second piston group 55 is suitable for performing a control action which allows both the control plate 42 and the gripper plate 41 to be positioned in a preferred axial position.

[00074] In accordance with some preferred embodiments, the control plate 42 and the gripper plate 41 are mutually engageable, so that the control plate 42, moved by the second piston group 55, also transmits the action on the plate clamp 41.

[00075] In accordance with a preferred embodiment, the control plate 42 and the gripper plate 41 are connected by means of the first piston group 54 controlled in block, ie extended.

[00076] According to the present invention, the gripper plate 41 and the control plate 42 are controllable in a starting operating configuration in which they are axially distal to each other. Preferably, by means of the first piston group 54 and by means of the piston group 55, the axial positioning of the plates remains unchanged, the action of the respective weight force being compensated.

[00077] According to a preferred embodiment, as already described , in said initial operating configuration the gripper plate 41 ? axially locked in a fixed position (preferably, due to the actuation of the brake member 53).

[00078] In accordance with the present invention, the control plate 42 is engageable by an industrial robot 910 and ? which can be guided, starting from its starting axial position, downwards towards the gripper plate 41, in such a way as to also move the spindle member 22 on the screwing tool 21 along the Z-Z axis.

[00079] Preferably, the control plate 42 is driveable in downhill movement along the Z-Z axis using the 910 industrial robot, at a speed? controlled and possibly according to the needs? variable.

[00080] Preferably, the industrial robot 910 adapts to the needs, adapting the descent action according to the occurrence of different situations.

[00081] In accordance with a preferred embodiment, the industrial robot 910 commands a speed? of descent according to the type of screw, and of the mechanical piece on which to screw the screw.

[00082] Preferably, the industrial robot 910 controls a speed? of descent varying over time also as a function of the different moments in accordance with which ? performed the screwing, for example by varying its thrust action or keeping it constant (but controlled) during tapping or screwing.

[00083] According to a preferred embodiment, the handling devices 5 allow the industrial robot 910 to guide the gripper plate 41 and the control plate 42 into positioning, to subsequently allow the industrial robot 910 to control the axial movement of the control plate command 42.

[00084] In accordance with a preferred embodiment, the tightening apparatus 1 allows that by means of the industrial robot 910 ? the positioning of the gripper plate 41 and of the control plate 42 can be controlled, in a starting operating configuration starting from which, subsequently the operations of feeding the screw into the gripping organ 20 are carried out and subsequently the screwing operations are carried out, by means of the movement of the control plate 42.

[00085] According to a preferred embodiment, said starting operating configuration ? axially comprised between a lower operating configuration and an upper operating configuration.

[00086] Preferably, the axial position of the gripper plate 41 in the lower configuration and the axial position of the gripper plate 41 in the upper configuration have a relative distance between 50 and 150 mm, preferably have a relative distance of 100 mm.

[00087] In other words, the tightening apparatus 1 ? specially shaped to allow the industrial robot 910 to axially position the gripper plate 41 and the control plate 42, as well as subsequently, once the gripper plate 41 is blocked axially by means of the pneumatic brake member 53, it allows controlled movement of the control plate 42.

[00088] In accordance with the present invention, the operating configurations are the configurations in which the different components can be positioned to perform the operations of feeding a screw to the screw collet 41; said configurations are multiple, comprised between the lower operating configuration (shown in figures 3 and 4) and the upper operating configuration (shown in figures 5 and 6).

[00089] In accordance with a preferred embodiment of the present invention, during the action of the industrial robot 910, the first piston group 54 does not perform any action.

[00090] Again, in accordance with a preferred embodiment of the present invention, during the action of the industrial robot 910, the second piston group 55 does not perform any action.

[00091] That is to say that the first piston group 54 and the second piston group 55 are suitable for cushioning the descent action, lightening the industrial robot 910 from the weight of the various components moved by it.

[00092] According to a preferred embodiment, said control plate 42 extends between one end? skate on which? mounted the second shoe 52 and one extremity? command to which ? the 910 industrial robot can be engaged.

[00093] Preferably, the screwing apparatus 1 comprising a coupling joint 6 housed on the control plate 42, at its end? command, which can be engaged by the industrial robot 910.

[00094] According to a preferred embodiment, the screw feed device 3? supported by drive plate 42 and gripper plate 41.

[00095] In accordance with a preferred embodiment, the screwing apparatus 1 is suitable for carrying out screwing operations on trilobe screws. Preferably, the tightening apparatus 1 ? engageable by means of an industrial robot 910 and the axial movement action, and therefore the thrust torque on the screw, ? suitable to be regulated by the drive of the industrial robot 910.

[00096] In accordance with a preferred embodiment, the tightening apparatus 1 and/or the automated tightening system 900 comprise a unit? command suitable for controlling the operations of the industrial robot and the operations of the screwdriving device 2 simultaneously.

[00097] Preferably, said unit? command ? also operationally connected to the screw feed device 3.

[00098] Preferably, said unit? command ? also operationally connected to the handling devices 5.

[00099] According to a preferred embodiment, the tightening device 2, the industrial robot 910, and the handling devices 5, are suitable for cooperating with a screw to perform untightening operations.

[000100] In particular, in accordance with a preferred embodiment, the screw gripper 20? when tightened, the spindle member 22 and the screwing tool 21 are moved in rotation in the opposite direction to the screwing direction; in addition, the control plate 42 ? controllable in ascent by the industrial robot 910; moreover, preferably, also the gripper plate 41? in turn moved uphill.

[000101] According to a preferred embodiment, the screw gripper 20 comprises gripping members 200 suitable for allowing a screw to be gripped and tightened. Preferably, said gripping members 200 can be opened and closed to allow the passage of a screw during gripping operations, but at the same time to allow gripping and tightening of the screw in unscrewing operations.

[000102] In accordance with a preferred embodiment, the screw gripper 20 comprises a pneumatic control member 250 which can be controlled pneumatically to command said gripping members 200 to open or close, thus commanding the release or gripping of a screw.

[000103] For example, preferably, by means of the pneumatic control member 250, the gripping members 200 are commands to open at the end of the unscrewing operations, to allow the screw to be rejected.

[000104] Preferably, said gripping members 200 are therefore normally closed and opened only when necessary.

[000105] Innovatively, the screwing apparatus and the system for automated screwing comprising said screwing apparatus in accordance with the present invention largely fulfill the predetermined purpose, overcoming the typical problems of the prior art.

[000106] Advantageously, the screwing apparatus ? specially shaped to allow the execution of the tightening operations with the cooperation of an industrial robot.

[000107] Advantageously, the tightening apparatus allows the industrial robot to manage the thrust of the tightening tool. Advantageously, this force ? adjustable by the industrial robot with a degree of precision in the order of a gram.

[000108] Advantageously, by means of the industrial robot ? a simple control of the axial position of the screwdriving device, in particular of the screwdriving tool and the spindle member, is permitted.

[000109] Advantageously, by means of the industrial robot ? It is possible to position the gripper plate and the control plate in a predefined starting configuration, in which the dimensions are well known via the industrial robot. Advantageously, by means of the industrial robot ? possible to always know the relative axial position of the control plate and therefore ? possible to know the position and the height of the screw.

[000110] Advantageously, all the actions associated with the tightening operations, for example the tightening torque, are partially downloaded to the industrial robot.

[000111] Advantageously, ? controllable speed? and follower plate descent force.

[000112] Advantageously, by means of the first piston group and by means of the second piston group ? the action of the weight force on the components can be downloaded. Advantageously, the industrial robot moves the components, but the axial movement action it must produce is? minimal, as the weight of the various components ? discharged onto said first piston group and onto said second piston group.

[000113] Advantageously, the pneumatic management of the different components ? extremely simplified.

[000114] Advantageously, the tightening apparatus also allows the execution of the untightening operations.

[000115] It is clear that a technician in the sector, in order to satisfy contingent needs, could make modifications to the invention described above, all contained in the scope of protection as defined by the following claims.

Claims (16)

1. A screwing apparatus (1) for an installation for the automated screwing (900) of screws on mechanical parts comprising an industrial robot (910) and a support apparatus (920), wherein the screwing apparatus (1 ) extends along an axis (Z-Z) and includes: i) a screwing device (2) comprising, along the axis (Z-Z), a screw gripper (20) for supporting and tightening a screw, a screwing tool (21) suitable for engaging a screw and a spindle member (22) suitable for controlling the rotation of the screwing tool (21); ii) a screw feed device (3) suitable for supplying screws to the screwing device (2), in particular to the screw gripper (20); iii) a support structure (4) comprising: - a base frame (40) which can be mounted integrally with the support apparatus (920); - a clamp plate (41), or lower plate, on which ? the screw pliers (20) are mounted; - a control plate (42), or upper plate, for supporting the screwing tool (21) and the spindle member (22), which extends orthogonally from the axis (Z-Z); iv) movement devices (5) mounted on the support structure (4) and operatively connected with the base frame (40), with the gripper plate (41) and with the control plate (42); wherein the gripper plate (41) and the drive plate (42) are controllable in a starting configuration wherein they are axially distal to each other and wherein the gripper plate (41) is ? axially locked in a fixed position; wherein the control plate (42) ? engageable by an industrial robot (910) and ? which can be steered by said industrial robot (910), starting from its starting axial position, descending towards the gripper plate (41), in such a way as to also move the spindle member (22) along the axis (Z-Z) on the screwing tool (21). The driving apparatus (1) according to claim 1, wherein the drive plate (42) is? which can be guided by said industrial robot (910) along the axis (Z-Z) also in return, ie towards said starting axial position. 3. Tightening apparatus (1) according to claim 1, wherein the movement devices (5) are suitable for allowing the axial movement of the gripper plate (41) and of the control plate (42) controlled by the industrial robot ( 910). 4. Screwing apparatus (1) in accordance with any one of the preceding claims, wherein the movement devices (5) comprise a first piston group (54) engaged with the gripper plate (41) and with the control plate (42) which can be controlled pneumatically in the block, i.e. in a mode? in which the gripper plate (41) and the control plate (42) are mutually integrally connected, and can be controlled pneumatically in release so as to allow the axial movement of the control plate (42) with respect to the gripper plate (41). The driving apparatus (1) according to claim 4, wherein the first piston assembly (54) is which can be controlled pneumatically to move the control plate (42) along the axis (Z-Z) to the starting axial position once the movement operations commanded by the industrial robot (910) have been completed. The driving apparatus (1) according to any one of the preceding claims, wherein the drive plate (42) is? can be guided in movement along the axis (Z-Z) by means of the industrial robot (910), at a speed? controlled and according to the needs? variable. 7. Screwing apparatus (1) in accordance with any one of the preceding claims, wherein the handling devices (5) comprise a pneumatic brake member (53), operatively connected to the gripper plate (41), wherein the member pneumatic brake (53) ? commanded, in the starting configuration, in a stop position in such a way as to axially block the gripper plate (41) along the axis (Z-Z). 8. Screwing apparatus (1) in accordance with any one of the preceding claims, wherein the movement devices (5) comprise a second piston group (55) engaged to the base frame (40) and to the control plate (42) suitable to cushion the action of the weight force of the control plate (42) and of the components housed on it. 9. Screwing apparatus (1) according to any one of the preceding claims, wherein by means of the industrial robot (910) ? the positioning of the gripper plate (41) and of the control plate (42) can be controlled, in a starting operating configuration, axially comprised between a lower operating configuration and an upper operating configuration, in which the axial position of the gripper plate (41) in the lower configuration and the axial position of the gripper plate (41) in the upper configuration have a relative distance between 50 and 150 mm, preferably have a relative distance of 100 mm. 10. Screwing apparatus (1) in accordance with any one of the preceding claims, wherein the movement devices (5) comprise at least one guide element (50) positioned on the base frame (40) extending parallel to the axis (Z-Z ), a first shoe (51) engaged to the gripper plate (41) suitable for sliding on said at least one guide element (50), a second shoe (52) engaged to the control plate (42) suitable for sliding on said at least one guide element (50). The tightening apparatus (1) according to claim 10, comprising a coupling joint (6) engageable by the industrial robot (910), wherein the drive plate (42) extends between one end? skate on which? mounted the second shoe (52) and one end? command on which ? the coupling joint (6) is housed. 12. Screwing apparatus (1) according to any one of the preceding claims, wherein the screw feeding device (3) is? supported by the drive plate (42). 13. Screwing apparatus (1) according to any one of the preceding claims, wherein the screwing device (2) and the movement devices (5), on command of the robot (910), are adapted to cooperate with a screw for perform unscrewing operations, in which the screw collet (20) ? locked, the chuck member (22) and the screwing tool (21) are moved in rotation in the opposite direction to the screwing direction, the control plate (42) ? can the gripper plate (41) also be moved during ascent? in turn movable in ascent. 14. Screwing apparatus (1) in accordance with claim 13, wherein the screw gripper (20) comprises gripping members (200) and a pneumatic control member (250) which can be controlled pneumatically to command the opening or closing of said members gripper (200) thereby commanding the release or gripping of a screw. 15. Screwing apparatus (1) in accordance with any one of the preceding claims, suitable for carrying out the screwing operations on trilobe screws. 16. Plant for the automated tightening (900) of screws on mechanical parts, comprising an industrial robot (910), a support apparatus (920) and a tightening apparatus (1) in accordance with any one of the preceding claims.