Patent Publication Number: US-2009234533-A1

Title: Programmed engine oil change notification system for an engine-driven welder/generator

Description:
BACKGROUND 
     The invention relates generally to the field of engine-driven electrical generators. More specifically, the invention relates to an engine oil change notification system that may be used in the operation of an engine-driven generator for various torch systems, such as a welding system, a cutting system (e.g., plasma cutting system), or the like. 
     Portable engine-driven generators (e.g., welder/generators) are commonly used to provide electrical power in locations where conventional electrical power is not readily available. Both gasoline and diesel engines are used to drive such generators, and the power produced is typically either 120 VAC or 240 VAC. Exemplary engine-driven generators include an oil system configured to provide oil for lubrication and operation of the engine. As expected, the lubricious properties of the oil may degrade over time due to a number of different operating parameter and variables (e.g., oil temperature, ambient temperature, engine load, etc.). Unfortunately, current engine-driven generators (e.g., welder/generators) fail to account for important operating parameters in determining when an oil change may or may not be desirable. Instead, oil changes for all units are generally performed according to a pre-set schedule, e.g., after a pre-determined number of operating hours (e.g., 25, 50, 100, etc.). Moreover, the pre-determined number of operating hours may be based on a worst case scenario that may not accurately reflect the quality of the oil in a specific generator (e.g., welder/generator) under actual operating conditions. This can lead to costly maintenance and repair and/or unnecessary oil changes. 
     BRIEF DESCRIPTION 
     Embodiments of the present invention provide an improved engine oil change notification system and method. The disclosed embodiments may include an engine-driven electrical generator having an oil system configured to provide oil for lubrication of the engine. The power generated by the electrical generator may be used for a torch operation (e.g., welding, cutting, or both), and the generator may include one or more power coils for general auxiliary power, welding power, cutting power (e.g., plasma cutting power), and so forth. Additionally, the disclosed embodiments may include a pair of cables for connection to a torch (e.g., a welding gun, a plasma cutting torch, etc.) and a work piece. 
     The disclosed embodiments may further include a plurality of sensors coupled to the engine, the generator, the oil system, and torch components (e.g., welding components, plasma cutting components, etc.). The plurality of sensors may be configured to measure operating parameters of the engine, the generator, the oil system, welding feedback, plasma cutting feedback, and so forth. For example, the plurality of sensors coupled to the electrical generator may include a voltage sensor, a current sensor, a temperature sensor, or a combination thereof. The plurality of sensors coupled to the oil system may include a temperature sensor configured to measure the temperature of the oil, a pressure sensor configured to measure pressure in the oil system, or a combination thereof. The plurality of sensors coupled to the engine may include a tachometer configured to measure engine speed, a position sensor configured to measure throttle position, or a combination thereof. The plurality of sensors coupled to torch components may include a voltage sensor, a current sensor, a temperature sensor, or a combination thereof. In sum, the sensors are configured to detect and measure operating parameters that may be used to determine the quality of oil for a specific generator under actual operating conditions. 
     The disclosed embodiments may also incorporate a processor coupled to the plurality of sensors. The processor may be configured to process signals from the sensors to determine a quality of the oil based upon the signal data. Further, the processor may be configured to time stamp the signal data and store the data in a memory coupled to the processor. The memory may include criteria data for determining the quality of the oil. For example, the criteria data may include empirical data, formulas, tables, rules, maps, historical data, or a combination thereof. 
     Finally, the disclosed embodiments may include a control panel that is coupled to the processor and configured to communicate the quality of the oil to an operator. The control panel may include a display configured to indicate total operating hours since the last oil change, remaining operating hours before the next oil change is due, a qualitative indication of the oil quality, one or more operating parameters measured by the plurality of sensors, an alarm for providing notice to an operator, or a combination thereof. Additionally, the alarm on the control panel may be an audible alarm configured to provide notice to an operator remotely positioned from the generator. 
    
    
     
       DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein: 
         FIG. 1  is a diagrammatical representation of an exemplary engine oil change notification system in accordance with embodiments of the invention, illustrating an engine coupled to an electrical generator (e.g., a welder/generator) that includes a processor and a control panel; 
         FIG. 2  is a diagrammatical representation of an exemplary processor in accordance with embodiments of the invention, illustrating a processor configured to receive signals from a plurality of sensors and process the signals for communication to a control panel; and 
         FIG. 3  is a flow chart illustrating a method of using one or more of the embodiments of the engine oil change notification system. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the present invention provide an engine oil change notification system and method for use with portable engine-driven generators and various torch systems (e.g., welding, cutting, etc.) having engine-driven generators. For example, specific embodiments incorporate the engine oil notification system into a portable welder-generator system, a portable plasma cutter-generator system, or a combination thereof. As discussed further below, embodiments of the oil change notification system may be used to tailor oil changes to operational conditions of each individual system, rather than using a common schedule for all systems. Thus, embodiments of the system include a plurality of sensors coupled to an engine, an electrical generator, an oil system, and torch system components (e.g., welding components, cutting components, or both). The plurality of sensor may detect and measure a number of operating parameters associated with the engine-driven generator that may be indicative of the oil quality in the oil system. These parameters may include engine feedback, generator feedback, welding system feedback, cutting system feedback, oil system feedback, and the like. The system may further include a processor that is coupled to the plurality of sensor. The processor accesses memory that includes criteria data to enable the processor to determine oil quality based on the compilation of historical and empirical data. In other words, the quality of the oil is determined based on actual operating conditions for a specific system, and is not based on one generic worst case scenario. This avoids unnecessary maintenance and repair costs that may result when the worst case scenario does not accurately reflect the actual operating conditions. Finally, the system includes a control panel that is coupled to the processor to communicate the quality of the oil to an operator. 
     Turning now to the drawings and referring first to  FIG. 1 , an embodiment of an oil quality system and/or an engine oil change notification system is illustrated and designated generally by reference numeral  10 . The illustrated embodiment includes an engine-driven generator-torch system  12 , which includes an engine  14 , an electrical generator  16 , a processor  18 , and a control panel  20 . The system  12  may include any type of system utilizing generator power. For example, the system  12  may include a welder circuit, a cutting circuit (e.g., a plasma cutting circuit), an induction heating circuit, or a combination thereof. The system  12  may further include an air compressor and/or other components driven by the engine. For purposes of illustration, the system  12  is described below as an engine-driven welder/generator  12 . Engine  14  may include a spark-ignition, internal combustion engine (e.g., gasoline engine) or a compression-ignition engine (e.g., diesel engine) having an oil system  22 , a drive shaft  24 , and a throttle  26 . Throttle  26  enables an operator to control the speed of the engine  14  and may include an analog or digital input. Further, drive shaft  24  is coupled to a rotor of generator  16  to enable the conversion of mechanical energy or power, created by engine  14 , into electrical energy or power via a rotor/stator system. In some embodiments, a clutch, a belt and pulley system, a gear box, or a combination thereof, may be used to couple the engine  14  to the generator  16 , an air compressor, or both. 
     Oil system  22  provides oil to the engine  14  for lubrication and general operation of engine  14 . The oil system  22  may include a plurality of sensors configured to detect and measure operating parameters of the oil system. For example, oil system  22  may include a pressure sensor  28  configured to measure oil pressure and a temperature sensor  30  configured to measure oil temperature. The pressure sensor  28  and temperature sensor  30  may be located in the oil sump or at any other suitable location in the oil system  22 . In sum, pressure sensor  28  and temperature sensor  30  measure and detect actual operating parameters of oil system  22  and may be used to determine the quality of the oil in that particular system under those particular operating parameters. 
     Without the disclosed oil change notification system  10 , the oil changes would be based on a single parameter, that is, the total operating time (e.g., hours, days, weeks, months, or the like) of the engine. For example, a typical oil change may occur at about 100 hours or 1 month of operating time, whichever occurs first. This operating time guideline is often based on a worst case scenario as pre-determined via laboratory testing. Further, the worst case scenario is purposely over conservative and may not accurately reflect the quality of the oil in a specific engine-driven welder under actual operating conditions. Therefore, embodiments of the present invention provide the advantage of determining the oil quality based on actual operating conditions of the welder/generator  12 , and avoid the generic, over-conservative approach. This is advantageous because it can reduce down time and maintenance cost by foregoing unnecessary oil changes. Moreover, the disclosed embodiments provide an additional level of protection by indicating that an oil change may be desirable when the actual operating conditions exceed those of the worst case scenario. 
     Similar to oil system  22 , drive shaft  24  and throttle  26  may include sensors or transducers for measuring and detecting operating parameters related to these engine components. For example, drive shaft  24  may include a tachometer  32  for measuring the rotations per minutes (rpm) of drive shaft  24  to determine engine speed and/or engine load. Likewise, throttle  26  may include a position sensor  34  to measure throttle position which may also indicate engine speed and/or engine load. Position sensor or transducers  34  may include a potentiometer, linear variable differential transformer (LVDT), proximity sensor, etc. 
     As discussed above, drive shaft  24  is coupled to generator  16  to generate electrical power. Specifically, drive shaft  24  is coupled to a rotor and stator system  36  of generator  16 . The rotor and stator system  36  converts the mechanical energy of drive shaft  24  into electrical energy or electrical power that may be used for a variety of applications. In certain embodiments, the generated power may be used for a welding operation or weld power  40 . However, as discussed above, other embodiments may provide welding power, cutting power, or other application-specific power, or a combination thereof. Additionally, the generated power may be used to power other electrical devices and may be referred to as auxiliary power  38 . Further, a power sensor  42  may be coupled to weld power  40  and/or auxiliary power  38  to measure the power output of the generator  16 . The power output is yet another operating parameter that can determine engine speed and/or engine load. Power sensors  42  may include a number of different sensors or transducers, such as a voltage sensor, a current sensor, or a temperature sensor. Additionally, weld power  40  and auxiliary power  38  may be generated from the same rotor and stator system  36  or may include individual rotor/stator systems, with each system including individual power sensors  42 . 
     All of the signals generated by the plurality of sensors that are coupled to engine  14  and generator  16  may be received by processor  18 . Processor  18  may include memory  44 , controller  46 , power supply  48 , and an internal clock  50 . As will be discussed below, processor  18  may time stamp the signals received from the plurality of sensors and store them in memory  44 . Further, controller  46  may be configured to generate and execute commands to determine the quality of the oil and communicate the results to an operator via control panel  20 . Control panel  20  may include a maintenance display  52  that includes an audio alarm  54 , meters  56 , and/or indicators  58 . The maintenance display  52  and alarms  54  will be discussed further below. In general, maintenance display  52  may be configured to indicate the quality of the oil in oil system  22  based, in whole or in part, on actual operating parameters for a specific engine-driven welder  12 . 
     As discussed above, the electrical power generated by generator  16  may be used for a welding operation, a cutting operation, and so forth. For example, torch  60  and ground cable  62  may be coupled to engine-driven welder  12  and used to perform a welding operation on a work piece  64 . Engine-driven welder  12  may be configured to perform stick electrode welding, MIG welding, TIG welding, or any other suitable welding operation. Further, the type of welding operation may directly impact the load placed on the engine. Therefore, the type of welding operation implemented is another operating parameter that notification system  10  may take into account to determine the quality of the oil. In other words, certain welding operations and applications inherently demand more power than others and thereby increase or decrease the load placed on engine  14 . 
     Finally, oil change notification system  10  may include a plurality of additional sensors for detecting and measuring other operating parameters and/or loads placed on engine  14 . For example, temperature sensor  66  may be included to measure the ambient temperature of the working environment, and may even be configured to record the ambient temperature when engine-driven welder/generator  12  is not operating. This can be advantageous in situations where welder/generator  12  is subjected to extreme environments that affect the temperature and pressure of the oil system regardless of engine operation. In other words, the temperature sensor may be configured to detect and measure changes in the oil system due to ambient temperature changes even though the engine-driven welder/generator  12  is not being used. Moreover, this type of operating parameter is not accounted for by exemplary engine-driven welders that base oil change recommendations strictly on total operating hours. Similarly, additional engine sensors  68  may be included to detect and measure other engine parameters that are indicative of operating conditions or oil degradation. For example, the spark ignition rate may be monitored and used to detect the engine speed and/or engine load. 
       FIG. 2  is a diagrammatical representation of an exemplary processor  18  configured to receive signals from a plurality of sensors and process the signals for communication to an operator via control panel  20 . The figure illustrates a program  72  that may be executed by controller  46  and processor  18 . Program  72  and controller  46  receive sensor signals  74  that may be a function of time (t). This is advantageous because the time stamped data can account for the duration that the engine and oil system operated under a given operating condition. In other words, each of the measured parameters can create a time history log of the operating conditions that may be directly compared to empirical data. This is important because some parameters may be easier to test in laboratory conditions than others and may not exhibit a linear relationship with oil quality. Therefore, having a complete time history log of each of these parameters enables the system to more accurately determine the oil quality in the system. 
     Referring to  FIGS. 1 and 2 , sensor signals  74  may be generated from any of the plurality of sensors coupled to the drive shaft  24 , throttle  26 , oil system  22 , generator  16 , and engine  14 . For example, tachometer  32  coupled to drive shaft  24  may generate a signal that is indicative of engine speed  76 . The engine speed data may be compiled with other sensor data to develop a history of the amount of time an engine operated under a given load. Likewise, position sensor  34  coupled to throttle  26  may generate a signal that is indicative of throttle position  78 . Again, throttle position  78  may be further indicative of engine speed or engine load, and may be compared to empirical data to determine the quality of the oil. 
     Temperature sensor  30  and pressure sensor  28 , coupled to oil system  22 , may generate signals that are indicative of oil temperature  80  and oil pressure  82 , respectively. This information may be compiled with other sensor data to indicate the quality of the oil in the oil system. For example, exemplary embodiments of the present invention are configured to maintain an oil temperature in the range of 150 degrees Celsius. However, a reduction in oil volume may result in an increase in the temperature and/or pressure in the oil system  22  that may not be detected by the other sensors. Therefore, temperature sensor  30  and pressure sensor  28  provide further insight into the quality of the oil in oil system  22 . 
     Further, temperature sensor  66  may generate a signal that is indicative of ambient temperature  84  of the working environment. This may be important when the engine-driven welder  12  is operated in extreme working environments, e.g., low or high temperatures. For example, exemplary embodiment of the present invention are configured to operate in environments having ambient temperatures as low as −28 Celsius or as high as 45 Celsius. Therefore, this ambient temperature data may be complied with the other sensor data to provide another indication of the quality of the oil in oil system  22 . 
     Finally, because engine-driven welders convert mechanical energy into electrical energy, detecting and measuring the electrical power output may be indicative of engine load and used as another indication of the quality of the oil in oil system  22 . Therefore, power sensor  42  may detect and measure the current and/or voltage for the weld power  86  and auxiliary power  88 . Moreover, these sensors may be easier to implement because they typically are not located on moving parts and/or are not required to measure mechanical motion. Similarly, engine sensors  68  may generate a number of engine signals  89  depending on the type and function of the respective transducer. 
     Processor  18  and controller  46  may be configured to receive sensor signals  74  for further processing and storage in memory  44 . Memory  44  may include criteria data for determining the quality or integrity of the oil located in oil system  22 . For example, memory  44  may include tables  90 , rules  92 , maps  93 , functions  94 , empirical data  96 , formulas  97 , historical data  98 , or a combination thereof. Tables  90  may include accessible data arrays grouped by operating condition or parameters. For example, tables  90  might include a life cycle analysis of the oil quality as a function of temperature and/or pressure. Specifically, one table or data array may include operating hours based on a fixed pressure with varying temperatures, or vice versa. The tables may be derived from empirical data and may provide for a direct comparison or provide bounds for the processor and program to interpolate between them. 
     Rules  92  may include logic structure to determine how to interpolate between tables  90  or how to evaluate the compiled data. Rules  92  may further provide the logic structure on how and when to notify an operator that the quality of the oil has degraded to a point that requires an oil change. Further, rules  92  may include threshold indicators that alert controller  46  to disable engine  14  to prevent possible engine damage. For example, a threshold indicator may be one that indicates that the oil is approaching a temperature that may result in complete thermal breakdown of the oil. 
     Maps  93  may also be included in the criteria data to help determine the quality of the oil in oil system  22 . Similar to tables  90 , maps  93  may be developed based on empirical data and/or current operating parameters for the given engine-driven welder  12 . For example, maps  93  may be used to determine the number of operating hours remaining before an oil change is desirable. Additionally, functions  94  may be generated based on historical data  98  and/or empirical data  96 , and may even include input from the operator. For example, an ambient temperature function may take into account the working environment temperature and apply a weighting factor based thereon. 
     Likewise, empirical data  96  and functions  94  may be used to develop formulas  97  to calculate the number of remaining operating hours before an oil change is recommended. The formulas  97  may be based on extrapolations or approximations of empirical data  96  or historical data  98 . Finally, historical data  98  may include actual data from the operation of a specific engine driven welder  12  and/or may include empirical test data developed under controlled conditions. Furthermore, historical data may include operating parameters since the last oil change and/or operating parameter for the entire life of the engine-driven generator. In this sense, the engine oil notification system  10  may provide for a number of “field laboratories” that can accumulate and report on the operating parameters for each unique environment and operating conditions. This might be advantageous in post-failure troubleshooting if an engine should stop functioning because of a failure in the oil system. 
     In sum, the processor  18  may determine the quality of the oil in oil system  22  via using a program  72  to process the criteria data located in memory  44 . This is advantageous over other exemplary engine-driven welders which fail to take into account operating parameters and rely strictly on total operating hours of the engine to determine oil change intervals. In other words, the plurality of sensors provide a plethora of data that may be processed and analyzed to determine the quality of the oil in that specific oil system based on actual operating conditions of that specific engine-driven generator. 
     Once the quality of the oil is determined, control panel  20  enables processor  18  and controller  46  to communicate the oil quality to the operator via a plurality of indicators. Referring to  FIGS. 1 and 2 , embodiments of the present invention include internal clock  50  that enables the system  10  to time stamp sensor signals  74  and historical data  98 . This further enables control panel  20  to provide the operator with a number of indicators based on temporal calculations. For example, control panel  20  may include an indication of the total operating hours  102  for the oil currently in oil system  22 . Likewise, control panel  20  may include an indicator of the remaining operating hours  100  for the oil currently in oil system  22 . The remaining operating hours may be calculated based on any of the criteria data located in memory  44 . Total operating hours  102  and remaining operating hours  100  may be displayed via a meter  56  located on control panel  20 . The meter may be an analog, digital, or any suitable meter that communicates the desired result. 
     Control panel  20  may also include a qualitative indication of the oil quality  104 , alarms  106 , and oil change status  108 . The oil quality indicator  104  may simply be a scaled indication that goes from an unremarkable or safe indication to an immediate attention or critical indication. Further, alarms  106  may include a visual and or audible alarm. The audible alarm may be configured to provide notice to an operator remotely positioned from the generator. Likewise, oil change status  108  may include a simple on/off indicator (e.g., LED) to communicate to the operator that it is time for an oil change. 
       FIG. 3  is a flow chart illustrating a method of using one or more of the embodiments of the engine oil change notification system  10 . Specifically, the figure illustrates logic that may be implemented by the processor  18  to determine the quality of the oil in oil system  22 . Referring to  FIGS. 2 and 3 , the process is initiated by processor  18  receiving sensor data  74  from the plurality of sensors (block  110 ). As discussed, the sensor data may include engine speed  76 , throttle position  78 , oil temperature  80 , oil pressure  82 , ambient temperature  84 , weld current/voltage  86 , auxiliary current/voltage  88 , or other sensor data, or a combination thereof. 
     Processor  18  then processes the sensor data  74  (block  112 ) and historical data (block  114 ) to integrate and compile the data (block  116 ). The complied data may then be stored in memory  44  (block  118 ) for further processing. Likewise, prior to compiling the data, processor  18  may evaluate the data to detect undesirable operating conditions as determined by rules  92 . Next, processor  18  may access and evaluate the criteria data (block  120 ) as directed by controller  46  and program  72 . As discussed, criteria data may include tables  90 , rules  92 , maps  93 , functions  94 , empirical data  96 , and formulas  97 . The criteria data may then be compared to the compiled data (block  122 ) and a determination of the quality of the oil may be made based on the comparison. Specifically, processor  18  or controller  46  may determine if an output is required or requested via control panel  20  (block  124 ). If an output is not requested or required, then the process is repeated and processor  18  receives the next packet of sensor data (block  110 ). If an output is required, processor  18  and controller  46  can display the output to the operator via control panel  20  (block  126 ). The output may include an indication of the oil quality, any of the measured parameters, an alarm, a message, and so forth. Finally, the decision process (blocks  120  through  126 ) may run concurrently with the reception process (blocks  110  through  118 ) in the form of a continuous loop. 
     Various embodiments of the systems and methods discussed above may include computer code stored on a computer-readable and/or machine-readable media; a controller that may be installed or retrofit into a portable engine-driven generator, welder-generator, or the like; a complete engine-driven system; and so forth. In certain embodiments, a method may include monitoring one or more parameters affecting life of oil in an engine of an engine-driven generator; and processing the one or more parameters to aid in timing of an oil change based on the one or more parameters. Similarly, in some embodiments, a system may include instructions disposed on a machine-readable media, wherein the instructions include instructions for monitoring one or more parameters affecting life of oil in an engine of an engine-driven generator, and instructions for processing the one or more parameters to aid in timing of an oil change based on the one or more parameters. Furthermore, in such a system, the machine-readable media may include memory disposed on a controller of a torch controller (e.g., a welding, cutting, or like controller). 
     While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.