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(11) | EP 3 695 935 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | VIBRATORY FINISHING MACHINE AND METHOD FOR ITS USE |
| (57) A vibratory finishing machine (10), said machine (10) comprising a finishing unit
(90) which includes a tub (30) capable of containing finishing media, said tub (30)
being mounted on a plurality of springs (80) connected to a base (60) and being mechanically
associated with vibratory means (70), the machine (10) further comprising a frame
(20) configured to hold at least one workpiece (40) to be subjected to vibratory finishing.
The workpiece holding frame (20) is provided with means for the automatic fastening
in a working position of the workpiece (40). The machine (10) is also provided with
a fixed support structure (50), said fixed support structure (50) being external to
said finishing unit (90) and being associated with a mobile structure (100) configured
to bring said frame (20) from a first position of assembly of the piece (40) to be
processed to a second position in which the piece (40) is immersed in the finishing
media inside the tub (30) and vice versa.
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FIELD OF INVENTION
PRIOR ART
[0002] Rectangular tub vibrators are well known, i.e. machines for vibrofinishing long items, such as tubes, bars and, in the case of the aerospace and energy sector, turbine blades that are more or less long and/or more or less heavy.
[0003] As is well known, a vibrator for vibratory finishing generally comprises a rectangular tub designed to contain finishing media and a frame configured to accommodate at least one workpiece to be subjected to vibratory finishing.
[0004] In turn, the tub is mounted on a plurality of springs connected to a base and is mechanically associated with at least one vibrator motor or to a vibrator connected to a motor by means of an appropriate connection that sets it in vibration.
[0005] The vibration of the tub gives a vibratory motion to the finishing media that allows the finishing operation on the workpiece.
[0006] In the case of turbine blades, for example, these need to be loaded into the machine beforehand and fixed to a frame, one side being much heavier than the other.
[0007] The frame with the blade mounted on it is then lowered into the finishing tub with the help of a crane and fixed, for example with handwheels, to the tub itself.
[0008] A first problem of this known technique is that the presence of the finishing media makes it difficult to lower the frame in the tub using the crane when the blade is mounted thereon.
[0009] A second problem is the fact that pre-assembling and then disassembling the frame of each blade subjected to vibrofinishing is a laborious and time-consuming operation.
[0010] It should also be noted that, as the average vibratory finishing cycle is of about 15-20 minutes, an operator cannot manage three vibratory finishing machines at the same time, at the rate of one frame being assembled and disassembled every 5 minutes.
[0011] The purpose of this invention is therefore to solve the problems described by means of a vibratory finishing machine that allows to simplify and speed up the loading and unloading operations of long parts such as turbine blades.
[0012] A further aim of this invention is to achieve the above results in a practical and economical way.
BRIEF SUMMARY OF THE INVENTION
[0013] The technical problems highlighted above are solved by a vibratory finishing machine, which includes a finishing unit, said finishing unit including a tub suitable to contain finishing media, said tub being mounted on a plurality of springs connected to a base and being mechanically associated with vibratory means, the machine further comprising a frame configured to accommodate a workpiece to be subjected to vibratory finishing.
[0014] According to an embodiment of the invention, the frame has means for automatic clamping of the workpiece in the working position.
[0015] In addition, the frame can be slid vertically along suitable guides from a first mounting or loading and unloading position of the workpiece to be finished to a second position where the workpiece can be immersed in the finishing media inside the tub and vice versa.
[0016] One advantage of the invention is that it enables the loading and unloading of workpieces to be handled quickly.
[0017] In particular, combining several machines according to an embodiment of the invention in a robotized island and served by an anthropomorphic robot a robotized system can be created that therefore has the ability to treat a blade every 5 minutes with obvious advantages of efficiency.
[0018] An embodiment of the invention comprises a vibratory finishing machine, wherein said machine comprises a finishing unit, said finishing unit comprising a tub suitable to contain finishing media, said tub being mounted on a plurality of springs connected to a base and being mechanically associated to vibratory means, the machine further comprising a frame configured to accommodate at least one piece to be subjected to vibratory finishing, characterized in that said frame is equipped with an element suitable to support, by means of clamping or interlocking, one side of the workpiece and with a mobile component driven by a jack or pneumatic cylinder to suitable act on the opposite side of the workpiece for automatic locking in the working position of the workpiece and by the fact that the said machine presents is equipped with a fixed support structure, wherein said fixed support structure is external to said finishing unit and is associated to a mobile structure configured to bring said frame from a first mounting position of the workpiece to be processed to a second position where the workpiece is immersed in the finishing media inside the tub and vice versa.
[0019] The invention also provides a method for carrying out vibrofinishing operations that includes a phase of assembly on the frame of the piece to be processed with the aid of an anthropomorphic robot, said assembly phase including a fastening phase by clamping one side of the workpiece and a fastening phase of the opposite side of the workpiece by the action of a mobile component operated by a jack or a pneumatic cylinder, a phase of immersion of the frame containing the piece in the tub by means of an action on a vertical axis of a mobile structure that carries the frame, a phase of vibratory finishing of the piece by means of the action of the vibrators on the tub and a phase of unloading of the piece by lifting the mobile structure carrying the frame and subsequent release of the jack or pneumatic cylinder and gripping of the piece by the anthropomorphic robot.
BRIEF DESCRIPTION OF THE FIGURES
[0021] Further features and advantages of the invention will be evident from reading the following description provided by way of non limitating example, with the help of the figures illustrated in the attached tables, in which:
- Figure 1 shows a side view of a vibratory finishing machine according to an embodiment of the invention in a first operating position;
- Figure 2 shows a top view of the vibratory finishing machine of Figure 1;
- Figure 3 shows an axonometric view of the machine of Figure 1;
- Figure 4 shows a side view of the machine of Figure 1 in a second operating position;
- Figure 5 shows a top view of the machine in the configuration of Figure 4;
- Figure 6 shows an axonometric view of the machine in the configuration of Figure 4;
- Figure 7 shows a side view of the rectangular tub vibrator in Figure 1 in a third operating position;
- Figure 8 shows a top view of the machine in the configuration of Figure 7; and
- figure 9 shows an axonometric view of the machine in the configuration of figure 7.
DETAILED DESCRIPTION OF SOME FORMS OF REALIZATION OF THE PRESENT INVENTION
[0022] With initial reference to figures 1-3, a side view of a vibratory finishing machine is shown according to an embodiment of the invention in a first operating position, said machine being globally indicated with numerical reference 10.
[0023] Machine 10 includes a rectangular tub 30 suitable for containing finishing media, where said tub 30 is mounted on a plurality of springs 80 connected to a base 60.
[0024] The tub 30 is mechanically associated to a vibrator motor 70 which vibrates the tub 30 in order to cause the abrasive and finishing action on the work piece of the media contained in the tub itself.
[0025] In general, the tub 30 is associated with vibratory means to be placed into vibration, the vibratory means including at least one vibrator motor or a vibrator, or a vibrating pack, wherein vibrating pack means a vibrator connected to others in line and finally to a motor.
[0026] In the figures, tub 30 is represented, by way of example, with a rectangular shape, but the shape of the tub can be chosen between rectangular, triangular, ellipsoidal, circular or other geometric shape depending on the application without limiting the scope of the present invention.
[0027] The tub 30, mounted on springs 80, the base 60 and the vibrator motor 70 form a finishing unit 90.
[0028] The machine 10 further includes a frame 20 configured to accommodate at least one workpiece 40 for vibratory finishing.
[0029] The frame 20 has means for the automatic locking in working position of the workpiece 40 to be machined and can be slid vertically along suitable guides 50 from a first mounting position of the workpiece 40 to be machined to a second position where it is possible to immerse the workpiece 40 in the finishing media inside the rectangular tub 30 and vice versa.
[0030] Machine 10 has in fact a fixed support structure 50 configured to support the frame 20, said structure 50 being external to the finishing unit 90 and is associated with a mobile structure 100.
[0031] The means for the automatic clamping in working position of the workpiece 40 to be machined include an element 42 to support one side of the workpiece 40 to be machined and a mobile component 46 operated by a pneumatic cylinder 45 to act on the opposite side of the workpiece 40.
[0032] Obviously, instead of the pneumatic cylinder 45 a jack or other known means for automatic clamping of the workpiece in the working position can be used.
[0033] In other words, the frame 20 is always present in machine 10 and is similar to a workbench vice.
[0035] The assembly of a workpiece 40 to be machined, e.g. a turbine blade, is therefore done in the following way.
[0036] A robot supports the blade on the left side (also called blade root) in the figures, the blade having a shape that allows its support by interlocking or clamping, for example, with a component 42 associated to the frame 20, while the opposite side of the head (i.e. the tip) of the blade remains free and distant from the other side of the frame 20 when open (see also figures 2 and 3).
[0037] By the action of a hydraulic jack 52, the mobile component 46 is pushed to the left in figure 2 and then carried on the turbine blade head, said mobile component 46 presenting a plinth 47 made, for example, in elastic and resilient polyurethane to facilitate the locking of the blade on the frame 20 (see also figures 4, 5 and 6).
[0038] The fixed support structure 50 of the frame 20 and external to the finishing group 90, has a plurality of vertical uprights 55 and the mobile structure 100 associated with the fixed support structure 50 can be operated vertically along said uprights 55 by means of the action of the respective cylinder-piston groups 110.
[0039] This mobile structure 100 therefore allows to perform a phase of immersion of the frame 20 containing the workpiece 40 in the tub 30 along the vertical axis, followed by a phase of vibratory finishing of the workpiece 40, said phase taking place by vibrating the tub 30 and the media contained in it, by activating the vibrator 70 (see also figures 7, 8 and 9).
[0040] Finally, a phase of unloading the piece 40 by lifting the mobile structure 100 that carries the frame 20 is performed.
[0041] It is therefore clear that the assembly of the workpiece, the immersion of the workpiece in the tub 30 and the unloading of the workpiece have been automated and speeded up thanks to the invention described.
[0042] According to an embodiment of the invention it is possible, for example, to realize a robotized system that includes three vibrofinishing machines 10 as shown above, placed in the same operating island and served by an anthropomorphic robot (not represented because known in the art), a robotized system that therefore has the ability to treat a blade every 5 minutes with obvious advantages of efficiency.
1. A vibratory finishing machine (10), said machine (10) comprising a finishing unit
(90), said finishing unit (90) comprising a tub (30) suitable for containing finishing
media, said tub (30) being mounted on a plurality of springs (80) connected to a base
(60) and being mechanically associated with vibratory means (70), the machine (10)
further comprising a frame (20) configured to hold at least one workpiece (40) to
be subjected to vibratory finishing, characterized in that said frame (20) is provided with means for the automatic fastening in a working position
of the workpiece (40) and in that said machine (10) is provided with a fixed support structure (50), said fixed support
structure (50) being external to said finishing unit (90) and being associated with
a mobile structure (100) configured to bring said frame (20) from a first position
of assembly of the piece (40) to be processed to a second position in which the piece
(40) is immersed in the finishing media inside the tub (30) and vice versa.
2. A machine (10) as in claim 1, in which the means for automatic fastening in the working
position of the workpiece (40) to be machined is equipped with an element (42) capable
of supporting by clamping one side of the workpiece (40) to be machined and with a
moving component (46) operated by a jack or a pneumatic cylinder (45) to act on the
opposite side of the workpiece (40).
3. A machine (10) as in claim 2, in which the mobile component (46) has a plinth (47)
made of elastic and resilient polyurethane.
4. A machine (10) as in claim 1, in which the fixed support structure (50) of the frame
(20) has a plurality of vertical uprights (55) and the mobile structure (100) associated
with the fixed support structure (50) can be operated along said uprights (55) by
the action of the respective cylinder-piston units (110).
5. A machine (10) as in claim 1, wherein the mobile structure (100) includes crossbars
(57) for supporting the frame (20).
6. A machine (10) as in claim 1, wherein the vibratory means (70) for vibrating the tub
(30) comprise at least a vibrator motor or a vibratory pack or a vibrator.
7. A machine (10) as in claim 1, in which the tub (30) has a shape chosen from rectangular,
triangular, ellipsoidal, circular or other geometric shape.
8. A plant for vibratory finishing processes including a plurality of machines (10) according
to the previous claims, said machines (10) being organized in a work island and served
by an anthropomorphic robot to perform loading and unloading operations of the workpieces
(40) to be processed.
9. A method for carrying out vibratory finishing operations using machines (10) according
to claims 1 to 7 and the plant according to claim 8, the method comprising a phase
of assembly on the frame (20) of the workpiece (40) to be processed with the aid of
an anthropomorphic robot, said assembly phase comprising a fastening phase by clamping
one side of the workpiece (40) and a fastening phase of the opposite side of the workpiece
(40) by the action of a mobile component (46) operated by a jack or by a pneumatic
cylinder (45), a phase of immersion of the frame (20) containing the workpiece (40)
in the tub (30) by action along a vertical axis of a mobile structure (100) that carries
the frame (20), a phase of vibratory finishing the workpiece by action of the vibratory
means (70) on the tub (30) and a phase of unloading of the workpiece (40) by lifting
the mobile structure (100) that carries the frame (20), a phase of subsequent release
of the jack or of the pneumatic cylinder (45) and a phase of gripping of the workpiece
(40) by the anthropomorphic robot.