WO2017168366A1

WO2017168366A1 - Cooling and suction system for heads for polishing ceramic manufactured items or natural stones

Info

Publication number: WO2017168366A1
Application number: PCT/IB2017/051829
Authority: WO
Inventors: Mario Corradini
Original assignee: Ancora S.P.A.
Priority date: 2016-04-01
Filing date: 2017-03-30
Publication date: 2017-10-05
Also published as: EP3436216A1; BR112018069672A2; EP3436216B1; ES2790892T3; ITUA20162251A1; CN109070310A

Abstract

A cooling and suction system for polishing heads (5) for polishing, for example by smoothing, lapping or the like, ceramic manufactured items (8) or natural stones, comprises at least one polishing head (5), provided with a plurality of tools (10), and first cooling and suction devices (13) arranged around each polishing head (5), second cooling and suction devices (14) arranged around the perimeter of the work zone of the ceramic manufactured items (8), or of the natural stones, and third cooling devices (15) arranged at the center and/or within each polishing head (5).

Description

TECHNICAL FIELD OF THE INVENTION

The present invention refers to a cooling and suction system for polishing heads for polishing, for example through smoothing, lapping or the like, ceramic manufactured items or natural stones.

STATE OF THE ART

With particular reference to the ceramic industry field, for producing manufactured items such as tiles, plates or bricks, or natural stones, it is known to carry out working, such as full smoothing or lapping, in order to improve the surface finish thereof.

These work operations are generally executed by means of machines which provide for the use of specific work heads comprising a main body that can be rotated around a relative axis and supporting a plurality of tools adapted for working manufactured items or natural stones.

In particular, the strong friction generated by the action of each tool on the manufactured item or on the natural stone leads to an overheating of the work tool itself, so as to render necessary the cooling thereof.

Water cooling systems are known which provide for the introduction of the cooling liquid by means of a feed duct that traverses the main body until it reaches the tools.

In detail, the body has a central opening for the outflow of the water in proximity to the work tools.

It is easy to understand that the use of water for cooling the work tools causes a non-negligible energy and resource consumption.

Another drawback is tied to the need to clean the cooling water and remove the relative muds, which involves considerable bureaucratic difficulties and management costs.

It was therefore proposed to substitute the water cooling with an air cooling, and air cooling devices for the tool are known from documents GB686260A, DE834518C, EP1832386B1 and WO-2001/70458A1 , for example.

Nevertheless, even the solutions described in these documents have not proven satisfactory due to the lower cooling capacity of air with respect to water, so that the tools and the manufactured items or the natural stones subjected to polishing were not sufficiently cooled.

Another problem of the known air cooling devices for the polishing tool is given by the dispersion of dust and residues of the polishing in the environment, since the air blown in the smoothing zone lifts and disperses the dust and residues of the polishing.

There is therefore the need to improve the technique of dry smoothing and/or lapping of the manufactured items such as tiles, plates or bricks, or of natural stones.

EP 1832386 Al teaches a solution according to the state of the art.

OBJECTS OF THE INVENTION

Therefore, the main object of the present invention is that of improving the state of the art in the field of cooling plants for polishing heads for polishing ceramic manufactured items or natural stones.

In the scope of such task, one object of the present invention is to provide a cooling and suction system for the polishing heads which allows the heads to work with an optimal cooling.

Another object of the present invention is to provide a cooling and suction system for polishing heads which allows effectively freeing and recovering the dusts and residues from the polishing zone, preventing dispersions in the environment.

Another object of the present invention is to provide a cooling and suction system for polishing heads which is easy to achieve, and at competitive costs.

These and still other objects of the present invention are attained by a cooling and suction system for polishing heads according to claim 1.

The dependent claims refer to preferred and advantageous embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Further characteristics and advantages of the present invention will be more evident from the detailed description of a non-exclusive embodiment of a cooling and suction system for polishing heads according to the present invention, given as a non-limiting example in the enclosed drawing tables in which:

figure 1 is a top perspective view of a polishing machine provided with a cooling and suction system according to the present invention;

figure 2 illustrates a perspective view of an enlarged and sectioned detail of the polishing machine pursuant to figure 1 ;

figure 3 illustrates a cross section of the polishing machine pursuant to the preceding figures;

figure 4 illustrates, in a schematic plan view, a polishing head with the relative cooling and suction system which form part of the polishing machine pursuant to the preceding figures;

figures 5 and 6 illustrate, in perspective view, portions of the polishing machine pursuant to the preceding figures with the heads provided with cooling and suction system according to the present invention; and

figures 7 and 8 illustrate, in perspective view, two embodiments of details pursuant to figure 6.

EMBODIMENTS OF THE INVENTION

With reference to the enclosed figures, a polishing machine for polishing ceramic manufactured items, natural stones or the like is indicated overall with the reference number 1.

The machine 1 comprises a support frame 2 which is associated with an abutment surface for ceramic manufactured items 8, or natural stones, movable along an advancement direction identified with the arrow 3 on an abutment surface 4.

The machine 1 comprises a plurality of heads 5 for polishing, for example through smoothing or lapping, ceramic manufactured items 8, or natural stones, the heads 5 are arranged one after the other along the advancement direction 3 and above the abutment surface 4. The heads 5 are driven by motor means 12 and are supported by at least two beams 6 oscillating according to a transverse direction 7.

Each polishing head 5 comprises a main body 9 and at least one tool 10 for working the ceramic manufactured items or natural stones associated with the main body 9. Each head 5 can comprise a plurality of tools 10 associated on the lower part with the body 9 due to the interposition of a support element 11.

These parts of the machine 1 are not described in more detail since they do not form part of the present invention, while it must be considered that the cooling and suction system, object of the present invention, can also be applied to a single polishing head 5, or possibly to two polishing heads 5, as will be clearer from the following description.

According to the present invention, the cooling and suction system for the polishing heads 5 comprises first bell-shaped cooling and suction means 13 arranged around each polishing head 5, second perimeter cooling and suction means 14 arranged around the perimeter of the work zone, i.e. on the sides of the ceramic manufactured items 8, or of the natural stones, and between one polishing head 5 and the next. Third cooling means 15 are also provided, arranged at the center and/or within each polishing head 5. It must be observed that the first cooling and suction means 13 and the third cooling means 15, arranged around, at the center and/or within each polishing head 5, are movable with the oscillating movement of each polishing head 5, hence the aforesaid first and third cooling means are always very close to the work zone where the heat is developed and the dust generated. According to that illustrated in figures 4 and 5, the first bell-shaped cooling and suction means 13 comprise a first opening 16 for dust suction, arranged in proximity to and around the tools 10.

For example, the first opening 16 can have ring shape, arranged concentrically with respect to the rotation axis of the polishing head 5 and be divided into several portions. In the embodiment illustrated in figures 4 and 5, the first ring-shaped opening 16 is divided into two portions 17 and 18, even if there can be any number of the aforesaid portions, starting from one.

The first bell-shaped cooling and suction means 13 also comprise a second opening 19 for sending a pressurized gas, for example air, for cooling the tools 10 and the work surface of the ceramic manufactured items 8, or of the natural stones, also this second opening 19 is situated in proximity to and around the tools 10. For example, the second opening 19 can be ring-shaped and be arranged around the first opening 16. According to one version of the present invention, also the second opening 19 is arranged concentrically with respect to the rotation axis of the polishing head 5 and divided into several portions.

According to that illustrated in figures 4 and 5, the second opening 19 is divided into two portions 20 and 21, even if there can be any number of the aforesaid portions, starting from one.

The third cooling means 15 arranged at the center and/or within each polishing head 5 are provided for sending a pressurized gas, for example air, for cooling the tools 10 and the work surface of the ceramic manufactured items 8, or of the natural stones, with a cooling function similar to that of the second opening 19.

The pressurized gas outlet end of the second opening 19 can have elongated slot shape or it can have a series of adjacent holes, similar to the outlet ends, illustrated in figures 7 and 8, of analogous cooling openings which make up part of the second perimeter cooling and suction means 14 and which will be better described hereinbelow.

The second opening 19 is oriented in a manner so as to send pressurized cooling gas jets into the work zone of the ceramic manufactured items, while the first suction opening 16 has a wide suction surface such to effectively suction the cooling gases and work dusts, lifted by the cooling gases, coming from both the third cooling means 15 in the center and/or within each polishing head 5, and coming from the second opening 19 arranged outside the first cooling and suction means 13.

In this manner, a double movement of cooling gases and dusts is attained, according to a substantially radial direction.

In figure 4, arrows 22 indicate a first part of cooling gases and work dusts, which come from the center of each polishing head 5 and go towards the first suction opening 16, and arrows 23 indicate a second part of cooling gases and work dusts, which come from the second opening 19 and go towards the first suction opening 16, and arrows 24 (figure 5) indicate the cooling gases and the work dusts suctioned from the first opening 16.

The first bell-shaped cooling means 13 and the third cooling means 15 in the center and/or within each polishing head 5 are situated very close to the work zone and determine an effective cooling of the tools 10 and of the ceramic manufactured items 8, or of the natural stones.

In addition, the cooling gases can be brought to low temperature by means of a suitable refrigerator, also termed chiller. The work dusts lifted by the cooling gases are sent to a centralized suction and filtration plant, in which the dusts are collected. Neither of these plants form part of the present invention and thus they are neither illustrated nor described in more detail hereinbelow.

According to that illustrated in particular in figures 5-8 and in relation to the advancement direction 3 of the ceramic manufactured items 8, or of the natural stones, the second perimeter cooling and suction means 14 comprise front and rear blowing means 25 and lateral suction means 26.

The blowing means 25 send cooling gases, indicated with arrows 28 (figures 5 and 6), onto the ceramic manufactured items 8, or onto the natural stones, and these cooling gases together with the work dusts are then suctioned by the lateral suction means 26 and also possibly by the first ring-shaped opening 16 adjacent to the polishing head 5.

The blowing means 25 allow delimiting the dispersion of the dusts between one polishing head 5 and the next. Indeed, the cooling gases 28 which exit from the blowing means 25, which are arranged at the front and rear for the entire length of the advancement conveyor belt, create a barrier that prevents the dusts from passing from a polishing zone to another zone.

This is particularly important since the polishing occurs progressively, starting from coarse-grained tools before finally arriving at tools with increasingly fine grain. The dusts that are generated with the coarse grain tools also have larger grain size than the dusts generated with the finer grain tools, and it is essential that the dusts with larger grain size do not enter into the zones where the tools with finer grain size are used, since they could scratch the parts that are already polished. The gas barrier generated by the blowing means 25 serves to eliminate this drawback. In order to further increase the barrier effect, the blowing means 25 are arranged tilted with a blowing direction opposite the advancement direction 3 of the ceramic manufactured items 8, or of the natural stones.

In this manner, the dusts are confined and sent back towards the polishing zones with larger grain size, and towards the suction means 26 and the opening 16 which then provide for suctioning the dusts.

The tilt angle of the blowing means 25 is comprised between 85° and 45° with respect to the work plane of the ceramic manufactured items 8, or of the natural stones.

In figure 7, an embodiment of the blowing means 25 is illustrated; these comprise a series of holes 32 adjacent to each other for the outflow of the cooling gases 28, while in figure 8 another embodiment is illustrated comprising slots 33 for the outflow of cooling gas jets 28. In both cases, the holes 32 and the slots 33 have an optimized shape in order to obtain powerful and concentrated cooling gas jets 28 that determine an effective barrier for the dusts that are generated in the polishing working. Also in this case, the cooling gases emitted by the blowing means 25 can be brought to low temperature by means of a suitable refrigerator plant.

As stated above, on the sides of the conveyor belt where the polishing heads 5 operate and where the ceramic manufactured items 8 or the natural stones transit, the lateral suction means 26 are situated which essentially comprise one or two tanks 27 that are arranged on at least one of the sides, or on both sides, of the polishing zone where each head 5 operates.

Each tank 27 comprises an elongated slit 29 which is situated at about the height of the work surface of the ceramic manufactured items 8, or of the natural stones, thus facilitating an effective suction of the dusts generated by the working of the tools 10. As an alternative to the elongated slit 29, a series of slots or a series of holes can be provided (not illustrated).

The tanks 27 are connected by means of a series of tubes 30 to a suction manifold 31, which has an increasing section, see in particular figures 1 and 2, in a manner so as to be adapted to the suction flow rate that increases according to the advancement direction 3.

Also in this case, the work dusts suctioned by the means 26 are sent to a centralized suction and filtration plant in which the dusts are collected.

The cooling and suction system, object of the present invention, operates in the following manner.

During the working of the polishing head 5 on the ceramic manufactured items 8, or on the natural stones, the first cooling and suction means 13 send a ring-shaped cooling gas jet 23 on the tools 10 and on the polishing zone of the ceramic manufactured items 8, or natural stones. The jet 23 is substantially ring-shaped and is oriented towards the rotation center of the polishing head 5. There is also another cooling gas jet 22 coming from the third cooling means 15 in the center and/or within each polishing head 5. In addition, within and substantially concentric with respect to the ring-shaped cooling gas jet 23, there is a suction opening 16 that is also substantially ring-shaped, which suctions the dusts generated by the polishing. The first cooling and suction means 13 and the third cooling means 15 are very close to the work zone and provide an effective cooling and suction in the work zone; it should be observed that these means 13 and 15 also follow the oscillating movements of the polishing head 5.

The second cooling and suction means 14 are fixed and are situated more distant from the polishing head 5 and in perimeter position with respect to the ceramic manufactured items 8, or natural stones. These second cooling and suction means 14 allow delimiting the dusts of different grain size between one polishing head 5 and the next, providing a further cooling on the work surface of the ceramic manufactured items 8, or natural stones; also provided is a lateral suction for the dusts in order to limit the dispersion in the environment.

It must be observed that the cooling gases can comprise only air taken from the environment, that is filtered, pressurized and with a humidity level that is optimized for obtaining an effective cooling without mixing the dusts generated during working, and possibly cooled, or the cooling gases can comprise other inert and/or noble gases, for example neon, argon, krypton, xenon, nitrogen, etcetera, or mixtures of these inert and/or noble gases with each other or with the addition of air.

The invention thus conceived is susceptible to numerous modifications and variations, all falling within the scope of the inventive concept.

In addition, all details can be substituted with other technically equivalent elements. In practice, the materials used, as well as the contingent sizes and shapes, can be of any type in accordance with requirements, without departing from the protective scope of the following claims.

Claims

1. Cooling and suction system for polishing heads for polishing (5), for example by smoothing, lapping or the like, of ceramic manufactured items (8), or of natural stones, which advance according to a given advancement direction (3), comprising at least one polishing head (5), rotating around one substantially vertical rotation axis and being provided with a plurality of tools (10), and with cooling and suction means (13, 14, 15) in order to cool work zones and suction dusts generated by the polishing process, characterized in that it comprises first cooling and suction means (13) arranged around each polishing head (5), second cooling and suction means (14) arranged around the perimeter of the work zone of the ceramic manufactured items (8), or of the natural stones, and third cooling means (15) arranged in the center and/or inside each polishing head (5).

2. System according to claim 1, wherein said first cooling and suction means (13) comprise a first opening (16) for dust suction, arranged in proximity and around the tools (10).

3. System according to claim 2, wherein said first opening (16) is ring-shaped, and it is positioned concentrically with respect to the rotation axis of the polishing head (5).

4. System according to any one of the preceding claims, wherein said first cooling and suction means (13) comprise a second opening (19) for sending a gas for cooling the tools (10) and the work surface of the ceramic manufactured items (8), or of the natural stones, said second opening (19) being located in proximity and around said tools (10).

5. System according to claim 4, wherein said second opening (19) is ring- shaped, and it is positioned concentrically with respect to the rotation axis of the polishing head (5).

6. System according to claim 4 or 5, wherein said first cooling and suction means (13) are bell-shaped and wherein said second opening (19) is oriented in such a way to send cooling gas jets (23) towards the work zone of the ceramic manufactured items (8), or of the natural stones.

7. System according to any one of the preceding claims, wherein said second cooling and suction means (14) comprise front and rear blowing means (25).

8. System according to any one of the preceding claims, wherein said second cooling and suction means (14) comprise lateral suction means (26).

9. System according to claim 7 or 8, wherein said front and rear blowing means (25) have a tilt angle between 85° and 45° with respect to the work plane of the ceramic manufactured items (8), or of the natural stones.

10. System according to claim 9, wherein said front and rear blowing means (25) comprise a plurality of holes (32) adjacent to each other, or slots (33) adjacent to each other for the release of cooling gas jets (28), said holes (32) or said slots (33) having a shape optimized in order to obtain powerful and concentrated cooling gas jets (28) such as to create an effective barrier against the dusts generated in the polishing process.

1 1. System according to any one of the claims from 8 to 10, wherein said lateral suction means (26) comprise essentially one or two tanks (27) arranged on at least one of the sides, or on both sides, of the polishing zone in which each head operates.

12. System according to claim 11, wherein each tank (27) comprises an elongated slit (29), or a series of holes, which is approximately at the height of the work surface of the ceramic manufactured items or of natural stones (8), in this way providing an effective suction of the dusts generated by the work of the tools (10).

13. System according to claim 11 or 12, wherein each tank (27) is connected to a suction manifold (31), which manifold has an increasing cross-sectional area in order to adapt to the suction flow rate which increases in said advancement direction (3) of the ceramic manufactured items (8), or of the natural stones.

14. System according to any one of the preceding claims, wherein said third cooling means (15) are arranged in the center and/or inside each polishing head (5).

15. System according to any one of the preceding claims, wherein said first cooling and suction means (13), said second cooling and suction means (14) and said third cooling means (15) are connected to a refrigerator system which determines a lowering of the temperature of the cooling gases and/or controls the humidity level present in said gases.

16. System according to any one of the preceding claims, wherein said first cooling and suction means (13) and said second cooling and suction means (14) are connected to a centralized suction and filtration system in which the work dusts are collected.

17. System according to any one of the preceding claims, wherein said cooling gases comprise air, or inert and/or noble gases, for example neon, argon, krypton, xenon, nitrogen, etc., or mixtures of these inert and/or noble gases, alone or with the addition of air.