Abstract:
The invention relates to machine for treating parts, for example for cleaning metal parts with solvents, transported in a basket in a treatment station, said machine including a plurality of treatment stations and a cylinder including a number of chambers at least equal to the number of stations, said chambers receiving at least one basket with said parts, the cylinder including sealing means and transporting the baskets into the chambers in the consecutive treatment stations of the machine.

Description:
[0001]    The present application claims the priority of earlier European patent application 09157007.7 of Mar. 31, 2009 the content of which is in its entirety incorporated by reference into the present application. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to machines for washing parts, for example metal parts used in industry. 
         [0003]    More specifically, the present invention relates to a machine for degreasing parts using solvent and/or hydrocarbons which can wash, degrease and dry said parts while remaining environmentally friendly. 
       PRIOR ART 
       [0004]    Such machines are known in the prior art and are marketed for example by the companies UNION SPA, TEKNOX, ROLL, FIRBIMATIC SPA, ECOBOME INDUSTRIE or DÜRR for example. 
         [0005]    Typically, these machines use a washing chamber into which a basket carrying the parts that are to be cleaned is introduced, for example into an appropriate housing. In some instances, inside this housing there is a basket holder structure that allows washing to be carried out either statically or in rotation. The chamber is connected to a circuit that sprays solvent over the parts that are to be washed, the circuit being connected to a pump. Washing can be done by spraying and/or by immersion. 
         [0006]    On the outlet side of the chamber there are discharge valves and filters for the used washing liquid. 
         [0007]    The part washing cycles generally comprise the following steps:
       introducing the basket into the chamber,   prewashing using a solvent by spraying;   rinsing with a solvent;   final washing   drying   deodorizing the chamber, for example by passing air over a filter, for example an active carbon filter, and   extracting the basket from the chamber.       
 
         [0015]    Such cycles and the machines that perform them do not perform well in as much as it is necessary to wait for all of the steps to have been completed before the basket can be taken out of the chamber. The total time taken to treat a basket is therefore equal to the overall sum of the times needed to complete all of the chosen steps, and what is more the significant volume of the chamber means also that significant quantities of solvent have to be treated (distilled) and that significant volumes of air have to be treated (vacuum, deodorizing). The throughput of such machines is therefore not optimized and, depending on the number of steps chosen, the cycle may prove particularly lengthy. 
       PRINCIPLE OF THE INVENTION 
       [0016]    The principle underlying the present invention differs (from what is currently done by manufacturers as indicated above), through the presence of several independent working chambers (for example five chambers instead of just one), which are mounted on a rotary carousel and which each in turn pass through the various stations described below. 
         [0017]    As a result, all the stations operate at the same time in parallel, as long as there is a basket at the corresponding station, and if not, the latter preferably switches to standby. As for the rest of the machine, all the peripherals (the distiller, the vacuum pump, solvent pump, tanks, separator, chiller, active carbon, filters, etc.) are standardized with respect to those currently used, but of smaller size and lower consumption. 
         [0018]    This design entails the use of a cylindrical basket provided with an identification (an optical identifier, barcode, etc.) specific to each different program that might be desired (in general, three are enough). 
         [0019]    The cycle time is thus reduced to a duration corresponding to that of the longest operation or step instead of still being the sum of the duration of all the operations or steps performed as it was in the prior art. 
         [0020]    Such a machine therefore has a far better throughput than the known machines. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0021]    The invention will be better understood through the description of one embodiment thereof and through the related figures, in which: 
           [0022]      FIG. 1  is a schematic diagram of a machine according to the invention; 
           [0023]      FIG. 2  is a perspective view of the machine according to the invention; 
           [0024]      FIGS. 3 and 4  are views of the machine from above, in two different situations; 
           [0025]      FIG. 5  is a perspective and part-sectioned view of the machine; 
           [0026]      FIG. 6  is a perspective and part-sectioned view of the machine; 
           [0027]      FIG. 7  is a perspective and part-sectioned view of the carousel; 
           [0028]      FIG. 8  schematically illustrates an active seal of the carousel; 
           [0029]      FIG. 9  is a partial view of the active seal; 
           [0030]      FIG. 10  is a perspective view of a basket. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    A schematic diagram illustrating the machine according to the invention is given in  FIG. 1 . In the middle of the figure is the carousel B according to the invention, which will be described in greater detail further on in this application. 
         [0032]    The various steps in the treatment cycle for treating the parts in the machine are depicted by way of illustration around the carousel B, each station corresponding to one step through which the carousel rotates. 
         [0033]    For example, starting from the empty position that allows the carousel B to be fed with and unloaded of baskets, in the clockwise direction the chamber arrives at the first step which is a prewash station. In the circuit needed for this step there is therefore at least one tank  1  containing a liquid (typically a solvent) and a pump  2  for circulating the solvent in the prewash circuit. For preference, a filter  3  is added to the circuit to filter the liquid that has been used. 
         [0034]    Next, the next station that the chamber arrives at as the carousel rotates clockwise is the wash station. In this circuit, there is therefore at least one tank containing the washing liquid, a pump  5  for supplying the station and a filter  6 . 
         [0035]    The next station in the clockwise direction of rotation is, for example, a combined vapor phase and drying station for the washed parts. At this station, first of all solvent vapors taken directly from the distiller  7  are circulated (to rinse and raise the temperature of the parts) then an absolute vacuum is created using a vacuum pump  9  (for drying by evaporation), passing through a condenser  8 . 
         [0036]    Finally, the last station of the machine rotating in the clockwise direction, in this example, is a deodorizing phase and the circuit comprises at least one condenser  8 , a vacuum pump  9 , an active carbon filter  10  and a fan  11 . 
         [0037]    Once the carousel B has rotated through one step more in the clockwise direction, the chamber that has passed through all the successive stations finds itself back again in the initial basket loading/unloading position and the treated basket can be removed and a new basket for treating loaded. 
         [0038]    Since in the system operates in a parallel mode, all the chambers of the carousel B are loaded with a basket, and so all the steps of the successive stations are performed in parallel on a different basket and the example given hereinabove relates to the successive steps applied to a basket in a given chamber. 
         [0039]      FIG. 2  is a perspective view of the step of unloading baskets from/loading baskets into a chamber and  FIGS. 3 and 4  are views from above. 
         [0040]    As these figures show, baskets  20 ,  21 ,  22  intended to be treated in the machine  30  arrive on a drip tray  26  (for example formed of rails). These baskets (which will be described in greater detail later on) contain parts that are to be treated, for example to be cleaned. The basket  22  is illustrated in a position in which it is grasped by a loading/unloading means  27 , for example a rotary means, which is used to remove the basket that has been treated (the basket  23  in  FIGS. 2 to 4 ) and bring in a new basket that is to be treated (the basket  22 ) over the chamber that is to accept it. The illustrated position of the loading/unloading means  27  is the position in which it has taken hold of the treated basket  23  that is leaving the machine  30  and the new basket to be treated  22  on the end of the drip tray  26 . In  FIG. 4 , the means  27  has rotated through approximately 90° in the counterclockwise direction such that the treated basket  23  is now on an exit/discharge drip tray  28  (for example rails) and the new basket to be treated  22  is in position to be fed into the machine  30 . As will have been appreciated from the foregoing, the baskets  24  and  25  are likewise baskets that have been treated and which are leaving the machine along the unloading line  28 . 
         [0041]    Of course, the loading/unloading means  27  is given by way of example and other equivalent means for loading and unloading baskets into and out of the machine are conceivable. 
         [0042]      FIG. 5  illustrates the means used for loading a basket into and unloading a basket from a chamber  31  of the machine  30 . The identical elements (baskets, loading or unloading drip tray) corresponding to  FIGS. 2 to 4  are identified by the same reference numerals. The loading/unloading means for example comprise a cylinder  80  and a piston  81  which are able, on the one hand, to push the treated basket  23  (or the next baskets) out of the chamber  31  (this is the situation illustrated in  FIG. 5 ) and then bring the new basket that is to be treated (in this case the basket  22 ) into the chamber  31  when the loading/unloading means  27  has moved them into their new position (as in  FIG. 4 ). 
         [0043]      FIG. 6  is a perspective and part-sectioned view of the machine. The components and elements that are identical to those already described are identified by the same numerical references. In this figure, apart from said elements already described (drip trays or rails  26 ,  28 , baskets  20 - 25 , machine  30 ) the carousel comprising the chambers  32 ,  33  (seen in section) containing baskets  20 ′,  21 ′ has been illustrated in greater detail. As will have been understood from the present description, the machine  30  comprises several stations, five stations in the embodiment illustrated, one being a basket loading/unloading station, which are evenly distributed in a circle which means that the rotating of the carousel  31  allows each chamber (notably the chambers  32 ,  33 ) thereof to move on to each of the stations provided. 
         [0044]    The successive stations are illustrated by the entries/exits  40 / 41  for the first station,  42 / 43  for the second station,  44 / 45  for the third station and  46 / 47  for the fourth station. Typically, these stations may correspond to those described with reference to  FIG. 1 . In alternative variants, different stations may of course be provided (for example having different functions). 
         [0045]    In this illustrative example, there are four stations and therefore five chambers in the carousel  31 , one station being provided for supplying the carousel with baskets and unloading these therefrom. It is of course possible to provide other numbers of stations (higher or lower numbers) than the number illustrated in this nonlimiting example. 
         [0046]    As described previously, the carousel  31  rotates about an axis  48  (for example mounted on ball bearings), driven by appropriate means (for example a motor or a system of gears or some other equivalent means) which have not been depicted, and causes each chamber to pass from one station to another successively so that the station can carry out the intended operation on the baskets brought in succession through the rotating of the carousel  31 . 
         [0047]    The carousel  31  and the chambers are depicted in greater detail in  FIG. 7 , in which the elements that are identical to those described previously are identified with the same numerical references. More specifically, the carousel  31  is formed for example of two disk-shaped plates  31 ′ and  32 ′ which are joined together by uprights  34 ,  34 ′ distributed about the circumference of the disks. These uprights are, for example, formed of rods with screws  35 ,  35 ′ at each end. The carousel  31  also comprises closed chambers  32 ,  33 ,  36  and  37  which are intended to contain the baskets. 
         [0048]    In this  FIG. 7 , the machine  30  is depicted partially dismantled in as much that, aside from the fact that the external casing has been removed in the figure, only the bottom wall  30 ′ and the uprights  30 ″ and  30 ′″ have been illustrated. The top wall is not illustrated and is fixed to the bottom wall  30 ′ by the uprights  30 ″ and  30 ′″ and the screws  38 ,  39 . The uprights  30 ″ and  30 ′″ are not restricted to two in number and are distributed about the circumference of the bottom wall  30 ′ and the top wall. 
         [0049]    In order to seal the chambers closed when the treatment of the station is performed, each chamber of the carousel  31  comprises, at each end, an active seal that will be described in greater detail later on. In  FIG. 7 , these seals are referenced  50 . To operate these seals, use is made for example of a compressed-air system with the air arriving along the axis  48  of the carousel  31 . A pneumatic circuit comprising a supply  60  which is connected to a distributor  61  is connected into the carousel. The distributor comprises a ring-shaped part and lateral branches  62  which open into the plates  31 ′,  32 ′ at the seals in order to operate these and seal the chambers closed when treatment is being carried out. 
         [0050]      FIG. 8  illustrates in detail the connection of a branch  62  of the distributor in the plate  32 ′ of the carousel, sealing being afforded by a seal  63  of the O-ring type. This cross-sectional detail is, for example, taken through the chamber  36  when it is at the first station  40 . The seal  50  comprises a cut washer  51  (for example made of metal) with two internal seals  52 ,  53  and one external seal  54 . The internal seals  52 ,  53  seal the chamber  55  which will be filled with air under pressure. This pressure will cause the seal to move (upwards in  FIG. 8 ) and this will compress the seal  54  against the upper part which is the top wall of the machine  30  thus hermetically sealing the chamber  36  because the seal  50  extends all around the chamber  36  and because there is another identical seal on the other side of the chamber (toward the bottom in the figure, but not depicted, activated in the same way). 
         [0051]    Thus, through suitable pneumatic control, by increasing the pressure it is possible to seal all the chambers hermetically using the active seal when the parts are to be treated and then, by releasing the pressure a little, the carousel can be turned by one step while still maintaining a certain level of sealing. 
         [0052]      FIG. 9  illustrates half a seal  50  in section and in perspective. As indicated, each end of the chamber has such a seal which allows each chamber to be sealed closed during treatment and prevent liquid, for example, used for the treatment, being released into the atmosphere. 
         [0053]      FIG. 10  schematically illustrates a basket as used in the present invention. This basket  70  is identical to the baskets  20 - 25  described in the preceding figures and the present description applies to these also. The basket  70  therefore preferably is of cylindrical shape and comprises an external wall  71  which includes openings to allow the treatment liquids to pass. For preference, this basket is made of stainless steel or some other equivalent material. At each end, the basket is closed by walls  72 ,  73 , likewise comprising openings for the same reasons. Such a basket is designed to contain, and suited to containing, the parts that are to be treated, for example that are to be cleaned, and the size of the openings must of course be suited to the size of the objects contained so that they remain inside the basket  70 . At each end of the basket  70  there is a circular flange  74 ,  75  which comprises laterally directed grooves  76 . These grooves allow the basket  70  to be turned in its chamber during treatment, for example when a liquid is injected through the chamber. This rotation improves the cleaning of the parts by agitating them in the basket  70  during the course of the treatment. 
         [0054]    For preference, the machine  30  is kept at a reduced pressure so as to avoid the possibility of any treatment liquid leaking out of the machine  30 . 
         [0055]    In the method according to the invention, it is necessary first of all to load the carousel which is assumed empty to start with. Thus, a first basket is loaded into the first chamber, then the carousel is turned through one step (so that the first chamber arrives at the first treatment station and an empty chamber arrives at the loading/unloading station). A second basket is then loaded into the second chamber and the carousel is turned by one step so that the second basket and the second chamber now arrive at the first treatment station while the first chamber and the first basket have moved on to the second treatment station. 
         [0056]    The same approach is used to load the third chamber which has arrived at the loading/unloading station, with a third basket and the carousel is rotated by one step. In this way, all the chambers and the baskets move on to the next station and so on as long as there are still empty chambers arriving at the loading/unloading station. As soon as the carousel has been filled, which means that the last empty chamber has received a basket, the next rotation brings on to the loading station the first basket that had been loaded into the first chamber at the outset. This basket has now completed a full treatment cycle and can be removed. As described above, this unloading is performed by a cylindrical piston which pushes the treatment basket out of the chamber and by a transfer means ( 27 , see  FIGS. 2 and 3 ) which means moves the treated basket and brings in a new basket to be treated. The cycle then continues with the carousel rotating by one step, which allows each chamber to move on to the new station and baskets to be exchanged at the loading/unloading station. 
         [0057]    This then is a system for the parallel treatment of each basket in each successive station which means that significant time can be saved. 
         [0058]    Of course, during loading (starting from a completely empty carousel) as long as the chambers are empty, treatment is preferably not performed in these chambers because there is no need for it. Likewise, if the carousel is to be completely emptied, there is likewise no need to operate the stations the chambers of which are empty with no basket in them. 
       Production Rate: 
       [0059]    Basket dimensions: diameter 80 mm×length 150 mm. 
         [0060]    Working volume of baskets: 0.51×8 (mean density of steel)=4 kg/basket. 
         [0061]    Each function is performed in 2 minutes, which is long enough given the small volume of the chambers, giving a rate of cleaned parts of 120 kg/hour. 
       Consumptions: 
       [0000]    
       
         
           
             Total electrical power: approx 5.6 kW 
             Cooling water: 501./hour 
             kWh/kg ratio=0.033 
           
         
       
     
       Key Advantages: 
       [0000]    
       
         
           
             4× more economical (solvent, electricity, cooling water) 
             Machine space requirement approx 2 m 3  (currently 8 m 3 ). 
             Low cost of construction, transport, materials. 
             The option to double the throughput, for example, all that is required is the construction of a carousel size that takes basket of diameter 90 mm×length 200 mm. This will increase the space occupied by the carousel to a diameter of just 350 mm (as opposed to 300 mm for 80 mm baskets). 
             The system is fully automated, so the operator does not have to be present at the end of the cycle to reload the machine and restart a program. 
             It can easily be made in stainless steel for the medical sector. 
           
         
       
     
       Preferred Machine Dimensions: 
       [0071]      
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Width 
                 1400 mm 
               
               
                   
                 Depth 
                 1000 mm 
               
               
                   
                 Height 
                 1200 mm 
               
               
                   
                   
               
             
          
         
       
     
       Tank Volumes: 
       [0072]      
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Prewash tank 
                 301 
               
               
                   
                 Wash tank 
                 201 
               
               
                   
                   
               
             
          
         
       
     
       Distiller: 
       [0073]      
         [0000]    
       
         
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Volume 
                 301 
               
               
                   
                   
               
             
          
         
       
     
       Preferred Powers: 
       [0074]      
         [0000]    
       
         
               
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Drum motor 
                 0.10 
                 kW 
               
               
                   
                 Solvent pump 
                 0.20 
                 kW 
               
               
                   
                 Refrigerating compressor 
                 0.80 
                 kW 
               
               
                   
                 Distillation element 
                 3 
                 kW 
               
               
                   
                 Fan 
                 0.50 
                 kW 
               
               
                   
                 Vacuum pump 
                 1 
                 kW 
               
               
                   
                   
               
             
          
         
       
     
       Basket Dimensions 
       [0075]      
         [0000]    
       
         
               
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Diameter 
                 80 
                 mm 
               
               
                   
                 Depth 
                 150 
                 mm 
               
               
                   
                 Volume 
                 0.77 
                 l 
               
               
                   
                 Working volume 
                 0.50 
                 l 
               
               
                   
                 Max load 
                 4 
                 kg 
               
               
                   
                   
               
             
          
         
       
     
       Productivity and Cycle Time 
       [0076]      
         [0000]    
       
         
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 4 kg/2 minutes 
               
               
                   
                 120 kg per hour 
               
               
                   
                 kWh/kg ratio = 0.033 
               
               
                   
                   
               
             
          
         
       
     
       Other Advantages: 
       [0000]    
       
         
           
             Reduced cost of manufacture (no drying tunnel, door, flap) 
             Simple to build and to maintain 
             Transportable for demonstration purposes 
             Rapid installation 
             Very little mass to be heated or cooled 
             Electrical energy saving 
             Solvent saving 
             Flexibility of washing, baskets commensurate with the quantities to be cleaned 
             Less handling on loading 
             No waiting time lost for restarting and selecting the program 
             Continuous and automatic operation 
             Possibility of adding an “express” basket without shutting down the machine 
             Flexibility to adapt to productivity rates 
             Each basket (identified) can have its own specific program 
             The injection of air or solvent may or may not be combined with the rotating of the baskets and the high speed of the flow (solvent) 
             No mechanized basket conveyor 
             Simplicity for the manufacturer to switch to a different size 
           
         
       
     
         [0094]    All the embodiments indicated above are given by way of nonlimiting examples and variations remain possible within the context of the present invention, notably through the use of equivalent means. 
         [0095]    The machine according to the invention can be used in all types of industry and for treating all types of products. 
         [0096]    As indicated, the number of chambers in the carousel and the number of stations can be varied by comparison with the examples indicated in the present application.