Patent Publication Number: US-11649757-B2

Title: Passive piston cooling nozzle control with low speed hot running protection

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of International PCT Application No. PCT/US20/44966 filed on Aug. 5, 2020, which claims the benefit of the filing date of U.S. Provisional Application 62/884,366 filed on Aug. 8, 2019, each of which are incorporated herein by reference in their entirety for all purposes. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to internal combustion engines, and more particularly, but not exclusively, to a piston cooling system having a passive fluid flow control device with low speed hot running protection. 
     BACKGROUND 
     Generally, fluid flow control devices have been used in internal combustion engines to control the flow of oil and other cooling fluids to provide cooling of one or more components of the engine. For example, piston cooling nozzles can be supplied with cooling fluid to be sprayed onto the underside of the piston to provide cooling at higher engine speeds. For passively controlled piston cooling nozzles, when the engine speed drops below a threshold speed, the supply of cooling fluid is stopped. However, the drop in temperature of the piston does not correspond identically with the drop in engine speed. Therefore, due to this heat soak of the pistons while the engine is running at lower speeds, damage may result to the pistons since cooling fluid is not supplied while the pistons are at higher temperatures. As such, there exists a need for improvement in fluid flow control devices for cooling of pistons in an internal combustion engine. 
     SUMMARY 
     The present disclosure includes a unique system and/or apparatus for cooling pistons in an internal combustion engine. The piston cooling system includes a reservoir from which fluid is fed and a piston cooling nozzle coupled to the reservoir and configured to direct the fluid fed from the reservoir for spraying the fluid onto a piston in the engine. The piston cooling system includes a fluid flow control device that connects the reservoir and the piston cooling nozzle. In one embodiment, the fluid flow control device includes a first chamber that opens to allow the fluid to pass from the reservoir to the piston cooling nozzle in response to the engine speed exceeding a first threshold. The fluid flow control device also includes a second chamber in fluid communication with the first chamber for receiving fluid fed from the first chamber through a check valve between the first and second chambers in response to the fluid flow control device being opened. At least one of the fluid flow control device and the check valve includes a clearance to bleed fluid from the second chamber into the reservoir to delay a closing of the fluid flow control device and allow cooling fluid to continue to be supplied for a predetermined period of time in response to the engine speed dropping below the first threshold. 
     Another embodiment includes a piston cooling nozzle device for controlling a flow fluid used for cooling pistons in an internal combustion engine. The device includes a fluid flow control device having a first chamber and a second chamber for housing fluid and configured to control the fluid flow between the first and second chambers. The fluid flow control device can include a check valve between the first and second chambers to regulate fluid flow from the first chamber into the second chamber as a fluid flow path to the piston cooling nozzle is opened in response to the engine speed being above a threshold. The fluid flow control device includes a clearance to bleed fluid from the second chamber into the first chamber to delay a closing of the fluid flow path in response to the engine speed dropping below the threshold. 
     This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The description herein makes reference to the accompanying drawings wherein like numerals refer to like parts throughout the several views, and wherein: 
         FIG.  1    is a schematic block diagram of an example engine lubrication system having a fluid flow control device, according to an embodiment of the present disclosure. 
         FIG.  2    is a section view of the fluid flow control device in a closed position at a low engine speed. 
         FIG.  3    is a section view of the fluid flow control device starting to move to an open position as the engine speed increases. 
         FIG.  4    is a section view of the fluid flow control device in the open position with fluid flow to a piston cooling nozzle. 
         FIG.  5    is a section view of the fluid flow control device moving from the open position toward the closed position in response to the engine speed dropping below a threshold. 
         FIG.  6    is a section view of a fluid flow control device, according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     For the purposes of clearly, concisely and exactly describing illustrative embodiments of the present disclosure, the manner and process of making and using the same, and to enable the practice, making and use of the same, reference will now be made to certain exemplary embodiments, including those illustrated in the figures, and specific language will be used to describe the same. It shall nevertheless be understood that no limitation of the scope of the invention is thereby created, and that the invention includes and protects such alterations, modifications, and further applications of the exemplary embodiments as would occur to one skilled in the art. 
     The present disclosure relates to a piston cooling system having a mechanically controlled fluid flow control device configured to open when an internal combustion engine requires piston cooling at high speed and then remaining open for a period of time after the engine speed drops below a threshold to prevent heat soak damage to the pistons. 
     Referring to  FIG.  1   , a schematic block diagram of an example engine lubrication system  100  for an engine  120 . The system  100  may include a sump  102  that contains engine oil or other fluid for lubricating and/or cooling the engine. The system  100  may also include a pump  104  to extract fluid from the sump  102  before the fluid is cooled by a cooler  106 , which may generally be used to remove surplus heat from the engine to use the fluid as a coolant. After the fluid is cooled, the fluid may be filtered in a filter  108  to remove any contaminants from the fluid. As shown in  FIG.  1   , the system  100  may optionally include a turbocharger  110 . The system  100  may further include a main fluid supply rifle  112  that is supplied fluid from the pump  104  and coupled to a piston cooling nozzle rifle  116  that provides the fluid to be sprayed via one or more piston cooling nozzles  118  onto one or more pistons of the engine  120 . 
     In an example embodiment, the system  100  may include a piston cooling nozzle passive fluid flow control device  114  to mechanically control the fluid flowing from the main fluid supply rifle  112  and direct the fluid to the piston cooling nozzle rifle  116 . It should be appreciated that fluid can be supplied to various components of the internal combustion engine as shown in  FIG.  1    such as, for example, connecting rods  122 , crankshaft  124 , valve train  126 , gear train  128 , and other accessories  130  (not listed). 
     Referring to  FIG.  2   , an embodiment of the fluid flow control device  114  is shown and designated at  200 . Fluid flow control device  200  may be coupled at one end to a fluid feed inlet  202 . The fluid feed inlet  202  may be, for example, a reservoir or passage that is connected to a main fluid supply such as fluid supply rifle  112  of  FIG.  1   . 
     In an example embodiment, the fluid flow control device  200  may include a plunger  204  housed in a fluid flow passage between the main fluid supply rifle  112  and the piston cooling nozzle rifle  116 . The plunger  204  is passively controlled to move to open and close a fluid flow path between the fluid feed inlet  202  and piston cooling nozzles  118  in response to engine speed. As the engine speed increases, the fluid pressure increases to act on and displace the plunger  204  to open the normally closed fluid flow path. As the engine speed decreases, the fluid pressure is reduced to allow the plunger  204  to return to its normally closed position and close the fluid flow path. 
     The plunger  204  may include a body  206  at one end and a base  208  at the other end. The plunger  204  includes a stem  210  that extends from the base  208  to the body  206  and separates the base  208  from the body  206 . The fluid flow control device  200  may include a one-way fluid flow control device such as a check valve  212  to allow fluid (e.g., oil) to flow only or primarily in one direction through base  208  of the plunger  204 . In the example embodiment, the check valve  212  is housed in the base  208  of the plunger  204 , but other arrangements and locations for check valve  212  are not precluded. In any embodiment, the check valve  212  may be provided to allow fluid to flow easily behind the base  208  of the plunger  204 . 
     Fluid flow control device  200  also includes a spring  214  and a plug  216  coupled to the body  206  of the plunger  204 . The spring  214 , for example, may be configured to apply force onto the body  206  which may normally bias the plunger  204  of fluid flow control device  200  to a closed position, such as shown in  FIG.  2   . 
     According to the example embodiment, the fluid flow control device  200  may be configured with a first chamber  218  and a second chamber  220  in fluid communication with one another through the check valve  212 . The first and second chambers  218  and  220  are configured to transfer fluid therebetween as the plunger moves to open and close the fluid flow path to the piston cooling nozzles  118 . For example, the second chamber  220  may receive fluid fed from the first chamber  218  through the check valve  212  in response to the fluid pressure increasing in the first chamber  218  as the engine speed increases. 
     According to an aspect of the present disclosure, the fluid flow control device  200  may be passively controlled to open and close in response to fluid pressure that is based on engine speed. In this case, the plunger  204  is configured to selectively open and close the fluid flow path between the fluid feed inlet  202  and piston cooling nozzles  118  in response to the engine speed being above or below a predetermined threshold. In  FIG.  2   , when the engine is running at a low engine speed below a threshold, fluid pressure (e.g., oil pressure) in the engine may not reach a pressure required to move the plunger  204 . Thus, when the engine is not running or runs at a low engine speed, the plunger  204  is normally biased to a closed position in the fluid flow control device  200  and the check valve  212  remains closed. In the closed position, the fluid flow path is closed such that fluid oil is prevented from flowing to the piston cooling nozzles  118  from outlet  222 . 
     Referring to  FIG.  3   , when the engine is running at a speed that is above a predetermined threshold, fluid pressure (e.g., oil pressure) increases to a pressure required to move the plunger  204  from the closed position toward an open position. The fluid pressure in the first chamber  218  acts on the end area of the body  206  to move the plunger  204  toward the open position (to the right in  FIG.  3   .) As the plunger  204  starts to move to the open position, the fluid pressure also opens the check valve  212  so that fluid flows into the second chamber  220 . The end area of the body  206  is greater than the area of the base  208  so the net force from the fluid pressure causes the plunger  204  to compress the spring  214 , overcoming a force biasing the plunger  204  to the closed position. In the example embodiment, fluid may flow from the first chamber  218  through the check valve  212  into the second chamber  220  as the plunger  204  moves from the closed position toward the open position so that the second chamber  220  fluid volume increases. 
     Referring to  FIG.  4   , the plunger  204  is moved to the open position so that the fluid flow path is completely open by displacement of the plunger  204 . In the open position, the fluid flow path between the fluid feed inlet  202  and the piston cooling nozzles  118  is opened allowing fluid to freely flow from the fluid feed inlet  202  to the outlet  222  for feeding to the piston cooling nozzles  118 . 
     Referring to  FIG.  5   , when the engine speed drops below the predetermined threshold, for example, after running at a high engine speed and dropping to a low engine speed having lower oil pressure, the check valve  212  closes. In this case, the check valve  212  closes and substantially prevents fluid flow from the second chamber  220  into the first chamber  218  except through a controlled clearance  224  of the plunger  204 . Therefore, fluid may continue to flow to the piston cooling nozzles  118  even after the engine speed drops below the threshold that forces the plunger  204  to open. 
     According to an example embodiment, the fluid flow control device  200  may be configured with a clearance  224  that is provided on the check valve  212 . The clearance  224  provided on the check valve  212  may be a hole or passage that is sized to allow the fluid to slowly bleed from the second chamber  220  to the first chamber  218  even if the check valve  212  is closed so that the plunger  204  slowly returns to the closed position under the bias of the spring  214 . 
     In yet another example embodiment, the fluid flow control device  200  may be configured with a clearance provided on or around an area that is around the plunger  204 . For example, a clearance  225  may be provided around the base  208  between the wall of the cavity or the rifle that houses the plunger  204  and the base  208  so that fluid can flow from the second chamber  220  to the first chamber  218  even if the check valve  212  is closed. 
     With the clearance  224  provided in the check valve  212  or, alternatively or additionally around the base  208  of the plunger  204  (e.g., clearance  225 ), the clearance  224  (and alternatively or additionally, the clearance  225 ) is configured to allow fluid to bleed from the second chamber  220  into the first chamber  218  and the fluid feed inlet  202  to delay the closing of the fluid flow control device  200  for a predetermined period of time in response to the engine speed dropping below the predetermined threshold. As the engine speed drops below the predetermined threshold, the clearance  224  allows the plunger  204  to return to the closed position slowly as oil evacuates the second chamber  220  and bleeds from the outlet  222  to the piston cooling nozzles  118  back into the inlet  202 . According to an aspect, for example, the slow return of the plunger  204  to the closed position keeps the fluid flow control device  200  open for a duration after the engine has been running at high temperatures, thus maintaining piston cooling and preventing or reducing piston damage from heat soak. 
     Referring to  FIG.  6   , another embodiment fluid flow control device  300  is provided that may be actuated by the intake manifold pressure and/or exhaust manifold pressure. Fluid flow control device  300  includes a plunger  304  housed in the fluid flow passage between the main fluid supply rifle  112  and the piston cooling nozzle  116  (see  FIG.  1   ). The plunger  304  may include a body  306  at one end and a base  308  at the other end. The plunger  304  includes a stem  310  that extends from one side  320  of the base  308  to the body  306  and separates the base  308  from the body  306 . At a side  322  of the base  308  opposite the one side  320 , the stem  310  extends through an opening  318  of the chamber  220  to an air pressure feed inlet  302  that is connected to a portion of an intake manifold (not shown) and/or exhaust manifold (not shown.) 
     According to the present disclosure, the fluid flow control device  300  may be passively controlled to open and close in response to air pressure fed from the intake manifold and/or exhaust manifold that increases or decreases in response to engine speed. In the example embodiment, the plunger  304  is configured to selectively open and close the fluid flow path between the fluid feed inlet  202  and piston cooling nozzles  118  in response to the engine speed being above or below a predetermined threshold. As the engine speed increases, air pressure from the inlet  302  increases to act on stem  310  in opening  318  and displace the plunger  304  to open the normally closed fluid flow path. As the engine speed decreases, the air pressure is reduced to allow the plunger  304  to return to its normally closed position and close the fluid flow path in a controlled manner as discussed above. There is a more direct correlation to the intake or exhaust manifold pressure and the engine load as compared to oil pressure. Therefore, this embodiment can provide cooling at high engine speeds and low loads, and also cooling at low engine speeds and high loads. 
     The fluid flow control device  300  may include a one-way fluid flow control device such as check valve  312  to allow fluid (e.g., oil) to flow only or primarily in one direction through base  308  of the plunger  304 . In the example embodiment, the check valve  312  is housed in the base  308  of the plunger  304 , but other arrangements and locations for check valve  312  are not precluded. In any embodiment, the check valve  312  may be provided to allow fluid to flow easily behind the base  308  of the plunger  304 . Fluid flow control device  300  also includes a spring  314  and a plug  316  coupled to the body  306  of the plunger  304 . The spring  314 , for example, may be configured to apply force onto the body  306  which may normally bias the plunger  304  of fluid flow control device  300  to a closed position. 
     Further written description of a number of example embodiments shall now be provided. One embodiment is a piston cooling system for an internal combustion engine, comprising a reservoir from which fluid is fed, a PCN coupled to the reservoir and configured to direct the fluid fed from the reservoir for spraying the fluid onto a piston in the engine, and a fluid flow control device connecting the reservoir and the PCN, the fluid flow control device having a first chamber that opens to allow the fluid to pass from the reservoir to the PCN in response to at least one of an engine speed and an air pressure exceeding a first threshold, the fluid flow control device including a second chamber in fluid communication with the first chamber for receiving fluid fed from the first chamber through a check valve between the first and second chambers in response to the fluid flow control device being opened, wherein at least one of the fluid flow control device and the check valve includes a clearance to bleed fluid from the second chamber into the reservoir to delay a closing of the fluid flow control device for a predetermined period of time in response to the one of the engine speed and the air pressure dropping below the first threshold. 
     In certain forms of the foregoing system, the fluid flow control device includes a plunger that is movable to selectively open and close a fluid flow path between the reservoir and the PCN in response to the one of the engine speed and the air pressure being above and below the threshold. In certain forms, the plunger includes a base that separates the first and second chambers and the check valve is housed in the base. 
     In certain forms, the plunger includes a stem extending from the base to a body that is spaced from the base, and the first chamber is defined between the body and the base. In certain forms, the plunger is housed in a passage between a main oil supply rifle and a PCN rifle of the internal combustion engine. In certain forms, the plunger is normally biased to a closed position that closes the fluid flow path. 
     In certain forms, the plunger is movable from the closed position to an open position in response to a fluid pressure in the first chamber acting on the body that overcomes a force biasing the plunger to the closed position. In certain forms, fluid flows from the first chamber through the check valve and into the second chamber as the plunger moves from the closed position to the open position. 
     In certain forms, in response to the one of the engine speed and the air pressure dropping below the first threshold, the fluid flow control device is configured such that the fluid in the second chamber bleeds through the clearance to maintain the fluid flow control device open for a period of time after the engine speed drops below the first threshold. In certain forms, the fluid flow control device is passively controlled in response to fluid pressure that is based on engine speed. In certain forms, in response to the one of the engine speed and the air pressure dropping below the first threshold, the check valve is configured to close and substantially prevent fluid flow from the second chamber into the first chamber through the check valve. In certain forms, the clearance is located on the check valve and is a hole through the check valve having a predetermined size. In certain forms, the clearance is located around the plunger between the plunger and a wall around the plunger that extends between the first and second chambers. 
     Another example embodiment includes a piston cooling nozzle device for controlling a flow fluid used for cooling pistons in an internal combustion engine, comprising a fluid flow control device having a first chamber and a second chamber for housing fluid and configured to control the fluid flow between the first and second chambers, the fluid flow control device including a check valve between the first and second chambers to regulate fluid flow from the first chamber into the second chamber to open a fluid flow path to the piston cooling nozzle in response to one of an engine speed and an air pressure being above a threshold, wherein the fluid flow control device includes a clearance to bleed fluid from the second chamber into the first chamber to delay a closing of the fluid flow path in response to the one of the engine speed and the air pressure dropping from below the threshold. 
     In certain forms of the foregoing device, the fluid flow control device includes a plunger that is movable to selectively open and close the fluid flow path in response to the one of the engine speed and the air pressure being above and below the threshold. In certain forms, the plunger is normally biased to a closed position that closes the fluid flow path. 
     In certain forms, in response to the one of the engine speed and the air pressure dropping below the threshold, the fluid flow control device is configured such that the fluid in the second chamber bleeds through the clearance to maintain the fluid flow control device open for a period of time after the engine speed drops below the threshold. In certain forms, the fluid flow control device is passively controlled in response to fluid pressure that is based on engine speed. 
     In certain forms, in response to the one of the engine speed and the air pressure dropping below the threshold, the check valve is configured to close and substantially prevent fluid flow from the second chamber into the first chamber through the check valve. In certain forms, the plunger is movable to selectively open and close the fluid flow path in response to air pressure from one of the intake manifold and the exhaust manifold. 
     While illustrative embodiments of the disclosure have been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described and that all changes and modifications that come within the spirit of the claimed inventions are desired to be protected. It should be understood that while the use of words such as preferable, preferably, preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow. In reading the claims, it is intended that when words such as “a,” “an,” “at least one,” or “at least one portion” are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language “at least a portion” and/or “a portion” is used the item can include a portion and/or the entire item unless specifically stated to the contrary.