BARGAGLI PETRUCCI ENRICO (SM)
FR2307644A1 | 1976-11-12 | |||
KR100940876B1 | 2010-02-09 |
CLAIMS 1. An automatic plant for cleaning tyre moulds, where the moulds are composed of cheeks (1) and sectors (2), characterised in that it comprises a plurality of supporting frames (3) for the cheeks (1) and the sectors (2), means (4) for associating the cheeks (1) and the sectors (2) with the supporting frames (3), means (5) for moving the supporting frames (3), designed to make the cheeks (1) and the sectors (2) move along a cleaning cycle, a plurality of tanks (40) for cleaning the cheeks (1) and the sectors (2), ultrasound generators (46), designed to direct ultrasound onto the cheeks (1) and onto the sectors (2) in the tanks (40). 2. The plant according to claim 1 , characterised in that the associating means (4) comprise at least one vertical coupling (10), equipped at the bottom with rigid constraining means (10b) for constraining it to at least one cheek (1) and equipped at the top with a recess (10a), designed to rigidly constrain it to a supporting frame (3), in such a way as to stably position the cheeks (1) on the supporting frames (3). 3. The plant according to claim 1 , characterised in that the associating means (4) comprise at least one horizontal coupling (20), equipped at the bottom with rigid constraining means (20b) for constraining it to at least one sector (2) and equipped at the top with a recess (20a), designed to rigidly constrain it to a supporting frame (3), in such a way as to stably position the sectors (2) on the supporting frames (3). 4. The plant according to claim 1 , characterised in that the movement means (5) comprise a plurality of carriages (35) and at least one overhead travelling crane (50), which are designed to convey the supporting frames (3) along the cleaning cycle. 5. The plant according to claim 1 or 4, characterised in that the movement means (5) comprise at least one translating unit (51), designed to move the supporting frames (3) in the tanks (40). 6. The plant according to claim 1 , characterised in that the tanks (40) contain chemical compounds and heaters (61), designed to cause the temperature for implementing the treatments, in such a way that the movement of the cheeks (1) and the sectors (2) in the tanks (40) occurs in predetermined thermal conditions. 7. The plant according to claim 1 , characterised in that the tanks (40) comprise at least one alkaline treatment tank (41 ). 8. The plant according to claim 1 , characterised in that the tanks (40) comprise at least one rinsing tank (42). 9. The plant according to claim 1 , characterised in that the tanks (40) comprise at least one acidic treatment tank (43). 10. The plant according to claim 1 , characterised in that the tanks (40) comprise at least one passivation treatment tank (44). 11. The plant according to claim 1 , characterised in that the tanks (40) comprise at least one dewatering tank (45). 12. The plant according to claim 1 , characterised in that the ultrasound generators (46) each comprise a plurality of ultrasonic horns, which emit ultrasound at a variable frequency. 13. The plant according to claim 1 , characterised in that it comprises an electronic automation apparatus (52), equipped at least with a PLC (53), designed to automatically manage the cycle for cleaning the moulds to be treated. 14. The plant according to claim 7, characterised in that the alkaline treatment tanks (41) comprise at least one filtering apparatus (47), provided with at least one ceramic micro-filtering cartridge, in such a way as to retain moist muds. 15. The plant according to claim 1 , characterised in that it comprises an evaporator (49), designed to reduce the muds produced in the tanks (40) to dry waste. 16. The plant according to claim 1 , characterised in that the associating means (4) comprise at least one universal coupling (30), equipped with first rigid constraining means (30b) for constraining it to at least one cheek (1) and with second rigid constraining means (30c) for constraining it to at least one sector (2), and with a recess (30a), designed to rigidly constrain it to a supporting frame (3), in such a way as to stably position the cheeks (1) and the sectors (2) on the supporting frames (3). 17. The plant according to claim 12, characterised in that it comprises a plurality of immersible flanges (46a), designed to support the ultrasonic horns in the tanks (40). 18. A method for cleaning tyre moulds in an automatic plant, comprising a preliminary step of disassembling a mould into its parts constituted of cheeks (1) and of sectors (2) and a final step of recovering the cleaned cheeks (1) and sectors (2) and of reassembling the mould for use again, characterised in that it comprises the following steps: - associating cheeks (1) and sectors (2), separately and according to predetermined quantities, with supporting frames (3); - conveying the supporting frames (3) on carriages (35), to a loading - unloading area for a set of treatment tanks (40); - picking up, using an automatic overhead travelling crane (50), a supporting frame (3) from one of the carriages (35) and immersing it in the tanks (40) resting on a translating unit (51); - causing reciprocating motion of the supporting frame (3) using the translating unit (51); - transferring the supporting frame (3) to other tanks (40), there being at least one alkaline treatment tank (41), one rinsing tank (42), one acidic treatment tank (43), one passivation treatment tank (44), one dewatering tank (45); - automatic activation of ultrasound generators (46) at the same time as the supporting frame (3) is immersed and moved in the tanks (40); - depositing, using the overhead travelling crane (50), the supporting frame (3) on the carriage (35) in the loading - unloading area for the tanks (40); - moving the carriage (35) away from the loading - unloading area. |
AUTOMATIC PLANT FOR CLEANING TYRE MOULDS
Technical field
This invention relates to an automatic plant for cleaning tyre moulds.
The tyres nowadays mounted on most vehicles circulating on the roads all over the world, although of various types and sizes, having different structural and build features, cater for a wide range of capacities and performances for the diverse uses and vehicles for which they are intended. They have retained classic build patterns, but make use of the great technological and design development achieved over the years, as well as materials increasingly targeted for the specific use and therefore safer and providing improved performance.
Background art
Current construction of tyres involves the use of special moulds, usually made of aluminium alloys or steel, or even of mixed aluminium and steel material, in which pre-packaged elements are placed, comprising the carcass, the belt pack, the sides and the tread of the tyres.
The tyre is then vulcanised in a press, in which devices are mounted which contain the mould, divided into cheeks and sectors. After a series of vulcanisation cycles, the mould must be washed before it can be re-used: therefore, careful maintenance action is required, consisting of the removal of residues and adhered pieces of vulcanised rubber, which may remain particularly in the small cavities of shaped surfaces. Obviously, failure to remove such fragments could cause defects and imperfections on the moulded surface of the tyre, even capable of causing issues such as imperfect adherence to the rim, illegibility of the alphanumeric characters required by regulations, small weaknesses and alterations of the mechanical resistance and design features.
In the prior art, such removal is still carried out using manual means, constituted of mechanical tools such as thin drill bits, or devices, again manually operated, that shoot jets of granular materials such as sand, peening shot, dry ice.
More modern automatic machines are also used, which make use of jets of various similar substances, located inside covers or hermetically sealed environments and able to automatically orient themselves in all directions necessary for completely cleaning the parts of the mould.
However, such methods cause problems and unwanted effects, constituted of wear and corrosion which occur on the parts of the moulds, therefore, with possible damage to the metal moulding surfaces and consequent defects on the tyres produced.
Disclosure of the invention
The aim of this invention is, therefore, to reduce the limitations and eliminate the disadvantages mentioned above.
The invention, as characterised in the claims, achieves the aim by means of an automatic plant which, programmed flexibly for each type of mould, performs optimum cleaning of it for its re-use, without causing wear and defects that could compromise its future operation.
The main advantage of this invention is basically the fact that the quality of the tyres produced by the moulds treated in the plant is kept unchanged. A further advantage is the fact that automation and adjustment of the method allows a reduction in the number of operating personnel needed and reduced processing times, resulting in significantly less expensive management.
Another advantage of the invention is that it allows processing that is less hazardous than the traditional types of processing in the sector, with reduced environmental impact and improved safety at work for workers. Brief description of the drawings
Further advantages and features of the invention are more apparent in the detailed description which follows, with reference to the accompanying drawings, which illustrate an example of it without limiting the scope of the invention, in which:
Figure 1 is an overall diagram of the invention;
Figures 2 to 12 illustrate components of the invention, with some parts cut away to better illustrate others.
Detailed description of preferred embodiments of the invention
An automatic plant for cleaning tyre moulds, where the moulds are composed of cheeks 1 and sectors 2, comprises, as illustrated in the figures, a plurality of supporting frames 3 for the cheeks 1 and the sectors 2, means 4 for associating the cheeks 1 and the sectors 2 with the supporting frames 3, a plurality of tanks 40 for treating and cleaning the cheeks 1 and the sectors 2, means 5 able to move the cheeks 1 and the sectors 2 in the tanks 40 and in the cleaning cycle from one tank to another, ultrasound generators 46, suitable for directing ultrasound onto the cheeks 1 and onto the sectors 2 in the tanks 40.
The associating means 4 comprise a plurality of vertical couplings 10, equipped at the bottom with holes 10b which allow their joining by means of screws with the cheeks 1 , and equipped at the top with recesses 10a which form their fixed joint with the supporting frames 3, stably positioning the cheeks 1 on the supporting frames 3, as illustrated in Figures 2, 3, 6. The associating means 4 also comprise a plurality of horizontal couplings 20, equipped at the bottom with holes 20b which allow their joining by means of screws with the sectors 2, and equipped at the top with recesses 20a which form their fixed joint with the supporting frames 3, stably positioning the sectors 2 on the supporting frames 3, as illustrated in Figures 4, 5, 7.
Figures 9 and 10 show associating means 4 similar to those described above, but in which each vertical coupling and horizontal coupling 10, 20 may be associated with a pair of cheeks 1 and of sectors 2 respectively. Figure 11 shows an alternative solution, in which the associating means 4 comprise at least one universal coupling 30, equipped with first rigid constraining means 30b for constraining it to at least one cheek 1 and with second rigid constraining means 30c for constraining it to at least one sector 2, and with a recess 30a, designed to rigidly constrain it to a supporting frame 3, in such a way as to stably position the cheeks 1 and the sectors 2 on the supporting frames 3.
The movement means 5 comprise a plurality of carriages 35, suitable for transporting the supporting frames 3, with which the cheeks 2 and the sectors 1 are associated, to loading - unloading areas for the tanks 40, and at least one overhead travelling crane 50, able to automatically pick up from the carriage 35 a supporting frame 3 and to convey it from tank 40 to tank 40 and then put it back on the carriage 35, as illustrated in Figure 1. At each tank 40, the movement means 5 comprise at least one translating unit 51 , which, having receiving the supporting frame 3 from the overhead travelling crane 50, moves it with variable speed and in various ways in the tank 40.
The tanks 40 contain chemical compounds and heaters 61 , capable of causing the temperature for use of the chemical compounds, in such a way that the movement of the cheeks 1 and the sectors 2 in the tanks 40 causes their treatment to occur in predetermined chemical and thermal conditions, simultaneously with the action produced by the ultrasound generators 46.
For implementing the entire cleaning cycle, the tanks 40 comprise at least one alkaline treatment tank 41 , one rinsing tank 42, one acidic treatment tank 43, one passivation treatment tank 44, one dewatering tank 45. The alkaline treatment tanks 41 are preferably joined to a filtering apparatus 47, provided with at least one ceramic micro-filtering cartridge, in such a way as to retain moist muds. The plant in turn comprises an evaporator 49, designed to reduce the muds produced in the tanks 40 to dry waste. The tanks 40 are made of steel with thicknesses of approximately 3 millimetres, in such a way that they withstand the stress corrosion cracking caused by the chemical agents used, the power emitted by the ultrasound generators 46, the operating temperatures of between 50 and 100°C, the corrosive pollutants present in the dirt removed from the moulds.
The ultrasound generators 46 each comprise a plurality of ultrasonic horns, having a total power of 5,000 Watts, able to emit ultrasound at a variable frequency in a range of between 24 and 33 kHz.
The ultrasonic horns, each having power variable between 100 and 120W, are installed on immersible flanges 46a, illustrated in Figure 12, in a quantity of 10 or 12 ultrasonic horns per flange 46a.
In general, each tank 40 corresponds to four flanges 46a, meaning that the total power of the ultrasonic horns installed on them is between 4000 and 5000W.
Finally, the plant is equipped with an electronic automation apparatus 52, comprising at least a PLC 53, designed to automatically manage the cycle for cleaning the moulds to be treated: in particular, the power and the frequencies of the ultrasonic generators 46.
The method for cleaning tyre moulds in an automatic plant comprises a preliminary step of disassembling a mould into its component parts, that is to say, cheeks 1 and sectors 2 and a final step, at the end of the cleaning cycle, of recovering the cleaned cheeks 1 and sectors 2, followed by reassembling of the mould for use again.
During the cleaning cycle, the method comprises first, associating the cheeks 1 and the sectors 2, separately and in predetermined quantities, with the supporting frames 3, which are then conveyed on carriages 35 to a loading - unloading area for subsequent sending to the treatment tanks 40.
Then the overhead travelling crane 50, operating automatically, picks up one of the supporting frames 3 from one of the carriages 35, conveys it and deposits it, immersing it in a first tank 40, on a translating unit 51 located close to said tank 40 which causes reciprocating motion of the supporting frame 3. The overhead travelling crane 50 then picks up the supporting frame 3, to perform a programmed sequence of immersions and movements of said frame in the tanks 40, there being at least one alkaline treatment tank 41 , one rinsing tank 42, one acidic treatment tank 43, one passivation treatment tank 44, one dewatering tank 45.
The movement inside the tanks 40 is managed by two systems with variable speed: a "slow" system for the tanks 40 in which the ultrasound acts and a "fast" system for the passivation tanks 40.
In this way, the washing liquids effectively penetrate the ventilation channels, cleaning the air removal valves both inside and outside.
Simultaneously with said immersions and movements in the tanks 40, there is automatic activation of the related ultrasound generator 46. When the programmed cycle of treatments in the tanks 40 has finished, the overhead travelling crane 50 automatically returns the supporting frame 3 onto the carriage 35, in the area for loading - unloading the tanks 40.
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