Abstract:
A fluid injector includes a cavity in the fluid injector configured to receive a container of fluid to be injected by the injector; a controller configured to control the fluid injector, the controller further configured to monitor a condition of the fluid in the container and modify the operation of the fluid injector based on the condition of the fluid in the container; a valve assembly configured to control fluid from entering and leaving the fluid injector, the valve assembly operatively connected to the controller to be controlled by the controller; a sensor operatively connected to the controller and configured to sense at least one of an amount of fluid in the container and an amount of fluid exiting the container; and an input device configured to input to the controller how much fluid should leave the fluid injector.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to fluid injectors. More particularly, the present invention relates to a method and apparatus for injecting oil and/or dye into an air conditioning unit. 
     BACKGROUND OF THE INVENTION 
     Modern compressors used in air conditioning units, for example for automobiles, may be high voltage compressors and do not fully insolate the windings of the compressors. As a result, the oil used to lubricate the compressors should be relatively free from moisture. Otherwise, moisture contained in the lubricating oil could potentially cause a problem in the high voltage compressor. In view of this situation, many automobile manufacturers are taking steps to ensure that the oil used in lubricating a compressor contains no or only relatively small amounts of moisture. Oil left in an opened container may be unsuitable due to moisture in the air contaminating the oil. 
     At least one automobile manufacturer requiring that the oil used when servicing the high voltage compressor comes from a never before opened container of oil. Thus, every servicing of a compressor requires a new container of oil. Such a situation can be not only expensive, but also wasteful. Therefore, it may be desirable to provide a method and apparatus that can address either or both of the above mentioned problems of providing relatively moisture free oil to a high voltage compressor and not having to waste left over oil used when a new container of oil is opened to service a high voltage compressor. 
     SUMMARY OF THE INVENTION 
     The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus and/or method is provided that in some embodiments provides relatively moisture free oil. Then the oil is injected into a compressor. 
     In one embodiment in accordance with the present invention, a fluid injector is provided. The fluid injector may include a cavity configured to receive a fluid to be injected by the injector; a controller configured to control the fluid injector, the controller further configured to monitor a condition of the fluid and modify the operation of the fluid injector based on the condition of the fluid; a valve assembly configured to control fluid from entering and leaving the fluid injector, the valve assembly operatively connected to the controller to be controlled by the controller; a sensor operatively connected to the controller and configured to sense at least one of an amount of fluid in the injector and an amount of fluid exiting the injector; and an input device configured to input to the controller how much fluid should leave the fluid injector. 
     In accordance with another embodiment of the present invention, a fluid injector is provided. The fluid injector may include: means for containing in the fluid injector configured to receive a means for containing fluid to be injected by the injector; means for controlling configured to control the fluid injector, the means for controlling further configured to monitor a condition of the fluid in the means for containing and modify the operation of the fluid injector based on the condition of the fluid in the means for containing; means for selectively permitting flow configured to control fluid from entering and leaving the fluid injector, the means for selectively permitting flow operatively connected to the means for controlling to be controlled by the means for controlling; means for sensing operatively connected to the means for controlling and configured to sense at least one of an amount of fluid in the means for containing and an amount of fluid exiting the means for containing; and means for receiving an input configured to input to the means for controlling how much fluid should leave the fluid injector. 
     In accordance with yet another embodiment, a method of injecting fluid is provided. The method may include monitoring a condition of a fluid in a container; indicating a fault if the condition of the fluid is outside a set parameter; receiving data regarding how much fluid to inject; and injecting an amount of fluid from the container according to the data. 
     There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
     In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
     As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a cut away side view of a fluid injecting apparatus in accordance with one embodiment of the invention. 
         FIG. 2  is a schematic diagram of an oil injecting apparatus including a valving system located at the front of the apparatus. 
         FIG. 3  is a schematic diagram of a control unit controlling various aspects of a fluid injecting apparatus in accordance with an embodiment of the invention. 
         FIG. 4  is a schematic diagram of a control unit controlling various aspects of a fluid injecting apparatus in accordance with another embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Various embodiments in accordance with the invention will now be described with reference to the drawing FIGS. in which like reference numerals will refer to like parts throughout. 
       FIG. 1  illustrates a cut away side view of a fluid injecting apparatus in accordance with one embodiment of the invention. As described above, some automobile manufacturers are now requiring previously unopened containers of oil to be used when servicing high voltage compressors. In accordance with this policy, some automobile manufacturers are selling or recommending relatively small containers of oil in the form of cartridges that may be used in an apparatus to inject new oil. The apparatus shown in  FIG. 1  may be designed to be compatible with cartridges of oil already available in the market. Other embodiments of the invention may be used with special proprietary cartridges of oil that may be available on the market at a future date. Still other embodiments of the invention may be compatible with oil that is placed into the injecting apparatus from a larger reservoir of oil. 
       FIG. 1  illustrates a cut away view of fluid injector  10 . The fluid injector  10  includes a housing  12 . The housing  12  provides a protective covering for the components contained within it and defines a cavity  17 . A cartridge  14  may fit in the cavity  17  and maybe the aforementioned small container of oil that may be currently available or in the future on the market. The cartridge  14  may be prefilled with oil already determined to have a low moisture content. Exposure of oil to the atmosphere may cause the oil to be contaminated with moisture from the atmosphere. As result it may be important to maintain the oil contained within the cartridge  14  which may later be transferred into the high voltage compressor to remain sealed off from ambient conditions so that moisture from the atmosphere or from ambient conditions does not contaminate the oil. The cartridge  14  contains a fluid  15  which, in may instances, is lubricating oil. Dye or ultra violet dye on its own or mixed with oil may comprise the fluid  15 . This dye may be used to help detect leaks. 
     The injector  10  further includes the valve assembly  16  at a front portion of the injector  10 . A hose  18  provides a fluid connection between the valve assembly  16  and a fitting  20 . The fitting  20  may be configured to mate with, and be coupled to, an air conditioning system  22  such as one in a vehicle. The fitting  20  may also be compatible with a air conditioning service unit  44  which can be attached to the air conditioning system in a vehicle  22 . In such a case, a Tee connection  42  may be used to connect both the injector  10  the air conditioning service unit  44  to the air conditioning system in a vehicle  22 . 
     Having the capability of connecting the injector  10  with an air conditioning servicing unit  44  may be desirable in certain situations because certain standards such as, SAE J2843 as being implemented for a refrigerant R-1234YF bans on board oil injection on air conditioning service units due to moisture concerns when used with high-voltage electric compressors. In the past, some air conditioning service units have had onboard oil injectors. However, in view of the standard as described above, the onboard injectors may no longer be available on onboard a/c service units. Therefore, a stand alone unit in addition to the injector  10  described above may be used. The injector  10  may be a small, portable handheld tool. 
     In some embodiments, the injector  10  may be configured to accept a cartridge  14  containing oil. The cartridge casing  24  may surround or define the cartridge  14 . An optical sensor  26  may be located in the injector  10  to optically measure an amount of fluid  15  contained within the cartridge casing  24 . Other sensors may be configured to detect a moisture content of the fluid  15 . 
     In some embodiments, the cartridge casing  24  may be see-through or translucent in order to permit the optical sensor  26  to sense an amount of fluid  15  contained within the cartridge casing  24 . 
     A plunger  28  is configured to urge against the fluid  15  contained within the cartridge casing  24 . In some embodiments of the invention, the plunger  28  may urge against the fluid  15  directly. In other embodiments of the invention, the plunger  28  may urge against the cartridge casing  24 . When the plunger  28  urges against the cartridge casing  24  or the fluid  15 , the fluid  15  contained within the cartridge case  24  may be expelled out of the cartridge casing  24  and through the hose  28  to the air conditioning system in the vehicle  22 . 
     The plunger  28  is equipped with a plunger rod  30  that serves to move the plunger  28  both against the fluid  15  or casing  24  or retract the plunger  28  from against the fluid  15  and/or casing  24 . The plunger rod  30  is actuated with an actuator  32 . The actuator  32  may be a motor such as an electric motor or may be a manually actuated. Examples of a manually actuated actuator  32  may include a lever such as a long trigger that allows a user to manually actuate the plunger rod  30  via the actuator  32 . Other manual actuators may also be used. In instances where the actuator  32  is an electric motor, the injector  10  may be equipped with a battery  36  which is configured to operate the actuator motor  32 . 
     In other embodiments of the invention, the injector  10  may be equipped with a plug-in cord which will allow the actuator  32  to be actuated by using line voltage when the plunger  10  is plugged into a wall socket. 
     The injector  10  may also be equipped with a plunger sensor  34 . The plunger sensor  34  may be configured to sense a distance the plunger  28  or plunger rod  30  has moved. By sensing the distance that the plunger  28  or plunger rod  28  has moved, it can be determined how much fluid  15  has been expelled or injected into the air conditioning system in the vehicle  22 . 
     In some embodiments in accordance with the invention, the injector  10  will be equipped with either of the optical plunger sensors  34  or the optical sensor  24  to measure the amount of oil. However, there maybe some embodiments in accordance with the invention equipped with some other type of sensors  56  (see  FIGS. 3 and 4 ), such a sensor for determining the moisture content of the fluid  15 . Other sensors may be used in embodiments that use cartridges  14  of fluid  15 . These sensors  56  may detect whether the cartridge  14  has been opened before. For example, if the cartridge  14  is vacuumed packed, a sensor  56  may determine if the vacuum in the cartridge is broken as the cartridge  14  is opened by the injector  10 . If the vacuum is not broken by the injector  10 , it would mean that the cartridge  14  had not already been previously opened. These other sensors  56  could convey their sensed information to a microprocessor  52  described later below. 
     In some embodiments the other sensor(s)  56  in combination with the microprocessor  52  could track how long the cartridge  14  has been opened after the cartridge  14  has entered the injector  10 . Tracking the time of how long the cartage  14  has been opened could be used in an algorithm carried out by the microprocessor  52  to determine if the fluid  15  in the cartridge  14  is acceptable to be used. The algorithm could include factors such as the temperature and the humidity of the air ambient air to the injector  10  as well as an amount of time the cartridge  14  has been opened to determine if the fluid  15  is acceptable to be used. 
     The sensors  24  and  34  conduct a similar function of measuring either an amount of oil or amount that the plunger rod  30  or plunger  28  has moved to estimate the amount of fluid  15  that has been injected into an air conditioning system  22  in a vehicle. The way the sensors  24  and  34  are used in making this estimation will be discussed further below with respect to  FIGS. 3 and 4 . 
     Turning now to  FIG. 2 ,  FIG. 2  is a schematic diagram of the cartridge  14  containing the fluid  15 . The valve assembly  16  and the fitting  20  are shown. The cartridge  14  and the fluid  15  are shown to be fluidly connected to the valve assembly  16 . The valve assembly  16  may include a solenoid valve  46  that may be operably connected to a solenoid  50 . The solenoid  50  may be receive its power from the battery  36  in embodiments that use a battery  36 . In other embodiments that use a cord to plug the injector  10  into a line voltage, the solenoid  50  may be actuated or provided power by the line voltage. The solenoid  50  may have a biased position that does not provide a fluid connection between the fluid  15  and the fitting  20 . However, when the solenoid  50  is actuated, the solenoid  50  actuates the solenoid valve  46  to provide a fluid connection between the fluid  15  and the fitting  20 . 
     In some embodiments of the invention, the amount of fluid  15  injected into a vehicle may be estimated using time. If the viscosity of the oil is known, than the microprocessor  52  may calculate how long the solenoid  50  needs to remain open to let a desired amount of fluid  15  into a vehicle. 
     A check valve  48  may be located between the oil cartridge  14  and the fitting  20  to ensure the fluid  15  does not move backwards from the fitting  20  into the cartridge  14 . 
       FIG. 3  is a block diagram showing a microprocessor  52  used to control various aspects of the injector  10 . The microprocessor  52  is connected to a display  38 . The display  38  allows a viewer to view various aspects of the injector  10 . For example, the display  38  may show an amount of oil that needs to be injected into an air conditioning system in a vehicle  22 . The display  38  can also show how much fluid  15  is contained within the cartridge  14 . The display  38  could also show various aspects and conditions of the injector  10  including whether or not the injector  10  is on and in condition to operate or if there is some faults associated with the injector  10 . 
     As shown in  FIG. 3 , the microcontroller  52  is operably connected to the solenoid valve  46  to control the solenoid valve  46  to selectively permit fluid  15  from the cartridge  14  to move through the hose  18  to the air conditioning system of the vehicle  22 . The microcontroller  52  is operably connected to the sensors  26  and  56 . As discussed above, the sensors  26 ,  34  and  56  can sense an amount of fluid or oil contained within the cartridge  14 , measure a distance that the plunger  38  or plunger rod  20  moves via the actuator  32  how much moisture is in the fluid  15 , whether a cartridge  14  has been previously opened or any other condition of the fluid  15 . While obtaining the information of how much the plunger  38  or plunger rod  20  has moved the microcontroller  52  is configured to calculate how much fluid  15  has been moved from the cartridge  14  to the air conditioning system of the vehicle  22 . 
     The microcontroller  52  may also be operably connected to a user interface  40 . The user interface  40  may include switches or buttons that allow a user to operate the injector  10 . The user interface  40  may be a keyboard or an other suitable interface. Examples of features the user interface  40  may allow the user to manipulate include increasing or decreasing an amount of fluid  15  to inject. Buttons labeled with up or down arrows may be used of any other labels may be used to provide other suitable user input. 
     The user interface  40  may also permit the user to override some of the settings of the injector  10 . For example, the user interface  40  may allow the user override settings to insert old fluid  15  or an old cartridge  14  into the injector  10 , whereas the injector  10 . In other embodiments of the invention the user interface  40  may not permit a user to over ride these settings. 
     The user interface  40  may allow a user to indicate whether the fluid  15  contained within the cartridge  14  is oil or a dye. The microcontroller  52  may alter how it controls the actuator  32  depending on whether the fluid  15  is an oil or dye. 
     A power source  36  is also operably connected to the microcontroller  52  in order to provide power to the microcontroller  52 . The actuator  32  is also operably connected to the microcontroller  52  so that the microcontroller  52  can control the actuator  32  to control how much it actuates the plunger  28  or plunger rod  30 . 
     A communication device  54  such as a wireless radio, Bluetooth or other similar system may be operably connected to the microcontroller  52 . A communication device  54  may be configured to communicate with an air conditioning service unit  44 . For example, an air conditioning service unit  44  may be used to drain the refrigerant from a system. When the refrigerant is drained from an air conditioning system oil may also be drained. A servicing unit  44  may measure how much oil has been drained from the system and may communicate this amount to the injector  10  via the communication device  54 . The communication device  54  may then input this amount into the microcontroller  52 . The microcontroller  52  may then control the actuator  32  to input a similar amount of oil into the air conditioning system in the vehicle  22  as it has been removed by the air conditioning service unit  44 . The microcontroller  52  may increase or decrease this amount based on additional information provided either by the interface  40  or by routines programmed onto the microcontroller  52 . 
     The block diagram shown in  FIG. 4  is similar to that as shown in  FIG. 3 . For example, the microcontroller  52  is operably connected to display  38 , a solenoid valve  46 , sensors  26 ,  34  and  56  a user interface  40 , a power source  36 , an actuator  32 , and a communication device  54  such as a wireless radio or Bluetooth device. The difference between the block diagram shown in  FIG. 3  and  FIG. 4  is that the power source  36  is not connected to the actuator  32  in  FIG. 4  as it is in  FIG. 3 . The block diagram shown in  FIG. 4  is for a manually operated actuator  32 . 
     The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.