Abstract:
A parts washer system includes a cleaning fluid and a sensor. In another aspect of the present invention, an industrial parts washer includes a housing, a conveyor, a cleaning solution and a particle detector. Still another aspect of the present invention employs a controller which is operable to stop the cleaning of an industrial part if a debris-to-cleaner ratio reaches a target value.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates generally to industrial machinery and more specifically to a parts washer system.  
           [0002]    Industrial parts washers are commonly used to remove debris, such as machining burrs, grease and dirt, from metallic parts such as engine blocks and crankshafts. Two such conventional devices are disclosed in Canadian Patent No. 669,262 entitled “Washing Apparatus” which issued to Umbricht on Aug. 27, 1963, and United Kingdom Patent No. 817,851 entitled “Improvements in or Relating to Washing Apparatus” which was published on Aug. 6, 1959. Another known industrial parts washer is disclosed in U.S. Pat. No. 3,059,861 entitled “Adjustable Spray Nozzle Assembly” which issued to Umbricht et al. on Oct. 23, 1962, and is incorporated by reference herein. Many traditional industrial parts washers typically flow a cleaning liquid onto the part for a predetermined period of time regardless of how clean the part actually is and regardless of part-to-part variability. Thus, the historical worst case scenario is commonly used to define the future predetermined period for cleaning which often leads to a sometimes slower than necessary process even for parts which are relatively clean after the prior machining operations.  
           [0003]    Other cleaning devices are known in different industries as disclosed, for example, in the following U.S. patent application and patents: US 2001/0015096 A1 entitled “Monitoring of Particulate Matter in Water Supply” which was published on Aug. 23, 2001; U.S. Pat. No. 5,647,386 entitled “Automatic Precision Cleaning Apparatus with Continuous On-Line Monitoring and Feedback” which issued to Kaiser on Jul. 15, 1997; and U.S. Pat. No. 5,560,060 entitled “System and Method for Adjusting the Operating Cycle of a Cleaning Appliance” which issued to Dausch et al. on Oct. 1, 1996; all of which are incorporated by reference herein. These conventional devices, however, appear to have little application in the industrial parts industry for cleaning machining burrs and manufacturing plant dirt, especially for large parts having long internal passageways.  
         SUMMARY OF THE INVENTION  
         [0004]    In accordance with the present invention, a parts washer system includes a cleaning fluid and a sensor. In another aspect of the present invention, an industrial parts washer includes a housing, a conveyor, a cleaning solution and a particle detector. Still another aspect of the present invention employs a controller which is operable to stop the cleaning of an industrial part if a debris-to-cleaner ratio reaches a target value. A method of operating a parts washer is also provided.  
           [0005]    The present invention is advantageous over conventional machines in that the present parts washer easily determines the cleanliness of an industrial part in a non-obtrusive and real time manner. Thus, the cleaning cycle can vary from part-to-part as needed. Accordingly, cleaning quality is improved for parts having excessive burrs and debris while cycle time is quickened for relatively clean parts. The present invention thereby improves overall processing speed and quality while reducing traditional energy costs to run the process based on average or worse case times. Additional advantages and features of the present invention will become apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    [0006]FIG. 1 is a diagrammatic view showing the preferred embodiment of a parts washer system of the present invention;  
         [0007]    [0007]FIG. 2 is a perspective view showing a portion of the preferred embodiment parts washer system;  
         [0008]    [0008]FIG. 3 is a side elevational view showing a portion of the preferred embodiment parts washer system;  
         [0009]    [0009]FIG. 4 is a perspective view, adjacent a part entry, showing a portion of the preferred embodiment parts washer system;  
         [0010]    [0010]FIG. 5 is a perspective view, adjacent a top corner, showing a seal and flush mechanism employed in the preferred embodiment parts washer system;  
         [0011]    [0011]FIG. 6 is a side diagrammatic view showing the seal and flush mechanism employed in the preferred embodiment parts washer system, with the mechanism in a raised position;  
         [0012]    [0012]FIG. 7 is a side diagrammatic view, like that of FIG. 6, showing the seal and flush mechanism employed in the preferred embodiment parts washer system, with the mechanism in a closed position;  
         [0013]    [0013]FIG. 8 is an end diagrammatic view showing the seal and flush mechanism employed in the preferred embodiment parts washer system, with the mechanism in a raised position;  
         [0014]    [0014]FIG. 9 is a diagrammatic top view showing a first alternate embodiment of the parts washer system of the present invention;  
         [0015]    [0015]FIG. 10 is a diagrammatic top view showing a second alternate embodiment of the parts washer system of the present invention; and  
         [0016]    [0016]FIG. 11 is a diagrammatic top view showing a third alternate embodiment of the parts washer system of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0017]    Referring to FIGS. 1, 2,  4  and  6 , the preferred embodiment of a parts washer system  21  is used in an industrial manufacturing plant to clean machining burrs, grease, dirt and other manufacturing debris from industrial parts or workpieces such as automotive vehicle powertrain components, including an engine block  23  (see FIG. 1), a metallic crankshaft  25  (see FIGS. 4 and 6), or the like. Parts washer system  21  operates as a cleaning station after a machining station (not shown) where the part has elongated internal pasageways or other features added by a milling machine, lathe, or similar automatic tools. Parts washer system  21  includes a sheet metal housing  27  affixed to the factory floor. Housing  27  essentially encloses the parts cleaning station yet has an entryway  29  for allowing access entry and exit by a horizontally moving shuttle  31  or other type of automatically operating conveyor. Shuttle  31  has a pair of parallel rails  33  upon which are mounted spaced apart perches  35  for carrying a set of parts  25  into the housing. A vertically movable access door (shown in a raised position in FIG. 2) is lowered after shuttle  31  moves inside housing  27 .  
         [0018]    FIGS.  4 - 8  show the internal components of parts washer system  21  for use with the crankshaft-type parts  25 . A programmable logic controller (“PLC”) first causes shuttle  31  to be automatically moved inside housing  27  to align each part  25  with a corresponding seal and flush unit  51 . Seal and flush unit  51  includes a set of offset and parallel upper seals  53  having a generally semi-circularcontacting surface shape made from a polymeric material such as polypropylene, polyurethane or nylon. Each upper seal  53  is affixed to a seal support  55  which has hollow bores to allow for internal fluid flow from an attached upper manifold  57 . A flexible in-flow pipe or hose  59  is coupled to upper manifold  57  whereby clean washing fluid sequentially flows through in-flow pipe  59 , through upper manifold  57 , through seal supports  55 , around a concave cross-sectional channel within the semicircular contacting surface of each upper seal  53 , which then contacts and seals against an upper matching surface of part  25 . Each seal and flush unit  51  further includes a set of lower seals  61  and hollow seal supports  63  which are all in communication with and coupled to an outflow manifold  57 . Lower seals  61  serve to collect the washing fluid that has been transmitted through the outside surface and internal passages in part  25  and then transfer the now dirty washing fluid to the outflow manifold  65 .  
         [0019]    A movement mechanism  71  employs a pivot bar  73  which is rotatably fixed to a frame  75 , stationary relative to housing  27 . An L-shaped arm  77  is rotatably cantilevered about pivot bar  73  at its elbow, and has a first end pivotally coupled to upper manifold  57  at a first pivot  79 . A roller  81  is coupled to an outside of an opposite end of arm  77  and is located between two upstanding structures  83  which are fastened to one of the rails  33  of shuttle  31 . Furthermore, guide pins  85  vertically slide within upstanding collars  87  affixed to a top wall of frame  75  in order to assist in accurate movement of the upper segment of seal and flush assembly  51 . Accordingly, normal movement of shuttle  31  and parts  25  from the initial loading position external to housing  27 , to the washing position aligned with seal and flush assembly  51  internal to housing  27  (parts  25  moving from right to left as shown in FIG. 8), causes structures  83  to rotate arm  77  about pivot bar  73  thereby lowering upper manifold  57  and the attached upper seals  53  to contact against part  25 . A proximity or other electrical switch senses that seal and flush assembly  51  has engaged parts  25 , whether directly or indirectly, and an appropriate signal is sent to the attached programmable logic controller  91  or other electrical control unit, such as a micro processor based personal computer controller  93  (see FIG. 3); the controller subsequently causes the cleaning process to begin by operating a set of motors and pumps to begin the flow of cleaning fluid.  
         [0020]    Reference should now be made to FIGS. 1, 3,  7  and  8 . A particle counter-type turbidity sensor  101  is coupled to an outflow pipe  103  which is, in turn, coupled to a downstream end of outflow manifold  65 . One satisfactory particle counter sensor  101  is a model 215W Liquidborne Laser particle counter which can be obtained from Met One of Grants Pass, Oreg. Such a particle counter sensor includes a water weir flow controller  105 , a sensor  107 , an electrical module  109  for power and communications, an adapter  111 , personal computer  93  for real-time sensing, data processing, storing and outputting particle counting data from the out flowing cleaning fluid and for comparing the actual sensed readings to either predetermined targets (representing a satisfactory cleaning fluid value or range) or previously sensed values thereby optimizing and controlling each washing cycle based on these real-time sensed values relative to the target values. In other words, the parts washer system performs by: (a) removing debris from a first machined workpiece by washing the first workpiece with a cleaning liquid; (b) sensing the cleanliness of the solution after workpiece washing; (c) communicating a signal of the sensed value to an electronic control unit; (d) automatically comparing the signal to a predetermined or target value; (e) determining the amount of debris in the liquid; (f) removing at least some of the debris from the liquid; (g) automatically varying a fluid flow characteristic of the liquid if the sensed value is substantially the same or different as compared to the predetermined value, wherein the characteristic includes, but is not limited to, re-using the liquid to subsequently remove debris from the same workpiece if the values are different, or automatically terminating the fluid flow and cleaning of the first workpiece if the sensed value of the liquid reaches the target debris-free value; (h) automatically removing the workpiece from the washer if the sensed value is substantially the same as the predetermined value; and (i) reusing the liquid to subsequently remove debris from additional workpieces. Furthermore, computer  93  stores, calculates and outputs historical statistical trends based on sensed cleaning fluid readings; this can include standard deviation and averaging calculations. Additionally, computer and particle counter sensor  101  can provide an output as to the filtering success for various desired time periods for the recycled cleaning fluid, in order to inform the operator as to when filter cleaning, cleaning fluid disposal or other maintenance may be desired in order to further optimize the process. The computer and particle counter sensor are further able to sense and calculate the cleanliness of the prior machining operations through sensed values and even if part aperture blockages have occurred as will be discussed in more detail with various of the alternate embodiments.  
         [0021]    [0021]FIG. 1 shows the remainder of the parts washer system  21  fluid flow outside of the housing. A “dirty” settling tank  121  is connected to the downstream end of outflow pipe  103 . A motor and pump  123  serve to pump cleaning fluid from tank  121  to a pre-filter separator  125  by way of another pipe  127 . Pre-filter separator  125  employs an approximately 75 micron filtering system. Machining chips, debris and other settled out or filtered out particulate matter is then moved and discarded by way of a conventional chip drag and chip waste mechanism  129 . A final filter assembly  131  is disposed downstream of pre-filter separator  125  to further filter out undesired particles and debris from the cleaning fluid by use of an approximately 50 micron filtering system. Final filter assembly  131  includes a media filter while pre-filter  125  employs a centrifugal filter. A “clean” settling tank  133  is located downstream of final filter assembly  131  and further allows for holding of the cleaning fluid for subsequent washing while allowing some additional particulate settling. Settling tank  133  includes a weir  135 , an overflow pipe  137  and a cleaning drain  139 . Another pump and motor  141  serve to flow the cleaning fluid from settling tank  133  to the part washing station within housing  27  when energized by the controller. It should be appreciated, however, that many other filtering and settling components can be used in place of or in addition to those disclosed herein. Notwithstanding, it is highly desirable to employ a closed loop and recyclable cleaning fluid system in order to reduce disposal costs and to save on cleaning fluid expense. The cleaning fluid is preferably a water borne, alkaline liquid solution containing a degreaser and a detergent. It is also envisioned that an electrolyte solution including disodium phosphate, sodium bicarbonate and water can be employed; such a solution is disclosed in U.S. Pat. No. 6,264,823 entitled “Non-Caustic Cleaning of Conductive and Non-Conductive Bodies” which issued to Hoffmann, Jr. et al. on Jul. 24, 2001, and is incorporated by reference herein.  
         [0022]    Only a single particle counter sensor is needed, thereby saving equipment cost and reducing controller processing speed requirements, however, it is alternately envisioned that a second particle counter sensor located upstream of the part to be washed can be used in addition to the downstream particle counter sensor  101  in order to allow a more direct comparison calculation of real-time sensed fluid value measurements by the controller without possible variations caused by the closed loop system filters and tanks.  
         [0023]    [0023]FIG. 9 illustrates a first alternate embodiment of a parts washer system  251  of the present invention. An in-flow pipe  253  and sealing unit  255  are automatically moved to contact and seal against a first side of an oil gallery, including a crankshaft bore, rocker arm paths, piston cylinder bores and the like, of an automotive vehicle engine block part or workpiece  257 . At an opposite end of the oil gallery of engine block  257 , an outflow pipe  259  and a corresponding sealing unit  261  are automatically moved to interface with part  257 . This occurs within a housing of a parts washing station such as in the closed loop system of FIG. 1. A particle counter sensor  263  is coupled to outflow pipe  259  and an electrical control unit  265  is electrically connected to particle counter sensor  263 . Thus, “clean” cleaning fluid automatically flows into the upstream side of part  257  and then exits as “dirty” cleaning fluid containing debris through outflow pipe  259 . At this point, particle counter sensor  263  senses the concentration of debris within the cleaning fluid and sends a corresponding signal to controller  265  for processing of this information and comparing the real-time sensed values to the target cleaning fluid particulate concentration values in order to further control the cleaning cycle time.  
         [0024]    [0024]FIG. 10 illustrates a second alternate embodiment of a parts washing system  301  of the present invention wherein an engine block part or workpiece is fully immersed or submerged into a tank  305  essentially filled with cleaning fluid. The cleaning fluid automatically enters through an upstream inlet  307 , flows through passageways in and completely around part  303 , and then subsequently exits through an outlet pipe  309  coupled to a particle counter  311  and an electrical control unit  313 .  
         [0025]    A third alternate embodiment parts washing system  351  of the present invention is shown in FIG. 11. An engine block part  353  or the like is placed within a housing of a cleaning station wherein a first end is automatically contacted by a sealing unit  355  connected to an in-flow pipe  357 . An opposite end of part  353  has a sealing plug unit  359  automatically attached. A set of outlet lines or tubes  371  is automatically moved to contact and seal against corresponding external openings such as piston cylinder bores, of part  353 . A cantilevered movement mechanism such as that disclosed with the preferred embodiment can be employed to automatically move lines  371  relative to part  353 . A flow sensor  373  is located within each line  371  to sense the volume, speed or pressure of fluid flowing through the corresponding line. An electrical control unit  375 , connected to the flow sensors  373  compares the real-time flow sensor readings against either predetermined desired target values or against a baseline reading from a flow sensor mounted within a diversion line  377  located upstream of part  353 . A diversion valve  379  allows for a diverted initial fluid flow through diversion line  377  at the beginning of each part cleaning cycle which may thereafter be shut off. The controller comparisons and calculations based on the flow sensor signals allow for an automatic and computerized determination of whether a blockage, such as by incomplete machining, is present in any internal passageway or aperture within part  353 . This provides real-time and automated quality control checking on every manufactured part even in hidden internal and elongated passageways. A particle counter sensor  381  is also positioned downstream and connected to outlet lines  371  and  377 . Particle counter sensor  381  is electrically connected to controller  375  to determine the concentration of debris or other undesired particles within the cleaning fluid to thereby automatically monitor and control the parts washing cycle for each part or batch of parts. It should be appreciated that the flow sensor inspection/monitoring, calculations and system control can be used independently of the particle counter sensor functions.  
         [0026]    Various embodiments of the present invention parts washer system have been disclosed, however, it should be appreciated that other modifications may be made. For example, while a liquid cleaning fluid has been disclosed, air or other gaseous cleaning fluids can also be used. It should also be appreciated that other nonindustrial and nonautomotive parts can be employed with the apparatus of the present invention although some of the advantages of the present invention may not be achieved. Furthermore, movement mechanisms such as those using sprockets and chains, jackscrews, cams or gears can be used instead of or in addition to the cantilevered mechanism disclosed. Moreover, magnetic, optical or electrical sensors can be substituted in place of the particle counter sensor disclosed, although the performance may vary. While various materials have been disclosed, it should be appreciated that other materials may be employed. It is intended by the following claims to cover these and any other departures from the disclosed embodiments which fall within the true spirit of this invention.