Patent Description:
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.

<CIT> discloses a piston cooling nozzle device for an internal combustion engine, having a fluid flow control device.

In a first aspect, the invention provides a piston cooling nozzle device for controlling a flow of fluid used for cooling pistons in an internal combustion engine, as set out in claim <NUM> appended hereto. 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.

In a second aspect, the invention provides an internal combustion engine including the piston cooling nozzle device of the first aspect.

Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

The description herein makes reference to the accompanying drawings wherein like numerals refer to like parts throughout the several views, and wherein:.

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, within the scope of the appended claims.

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>, a schematic block diagram of an example engine lubrication system <NUM> for an engine <NUM>. The system <NUM> may include a sump <NUM> that contains engine oil or other fluid for lubricating and/or cooling the engine. The system <NUM> may also include a pump <NUM> to extract fluid from the sump <NUM> before the fluid is cooled by a cooler <NUM>, 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 <NUM> to remove any contaminants from the fluid. As shown in <FIG>, the system <NUM> may optionally include a turbocharger <NUM>. The system <NUM> may further include a main fluid supply rifle <NUM> that is supplied fluid from the pump <NUM> and coupled to a piston cooling nozzle rifle <NUM> that provides the fluid to be sprayed via one or more piston cooling nozzles <NUM> onto one or more pistons of the engine <NUM>.

In an example embodiment, the system <NUM> may include a piston cooling nozzle passive fluid flow control device <NUM> to mechanically control the fluid flowing from the main fluid supply rifle <NUM> and direct the fluid to the piston cooling nozzle rifle <NUM>. It should be appreciated that fluid can be supplied to various components of the internal combustion engine as shown in <FIG> such as, for example, connecting rods <NUM>, crankshaft <NUM>, valve train <NUM>, gear train <NUM>, and other accessories <NUM> (not listed).

Referring to <FIG>, an embodiment of the fluid flow control device <NUM> is shown and designated at <NUM>. Fluid flow control device <NUM> may be coupled at one end to a fluid feed inlet <NUM>. The fluid feed inlet <NUM> may be, for example, a reservoir or passage that is connected to a main fluid supply such as fluid supply rifle <NUM> of <FIG>.

In an example embodiment, the fluid flow control device <NUM> may include a plunger <NUM> housed in a fluid flow passage between the main fluid supply rifle <NUM> and the piston cooling nozzle rifle <NUM>. The plunger <NUM> is passively controlled to move to open and close a fluid flow path between the fluid feed inlet <NUM> and piston cooling nozzles <NUM> in response to engine speed. As the engine speed increases, the fluid pressure increases to act on and displace the plunger <NUM> to open the normally closed fluid flow path. As the engine speed decreases, the fluid pressure is reduced to allow the plunger <NUM> to return to its normally closed position and close the fluid flow path.

The plunger <NUM> may include a body <NUM> at one end and a base <NUM> at the other end. The plunger <NUM> includes a stem <NUM> that extends from the base <NUM> to the body <NUM> and separates the base <NUM> from the body <NUM>. The fluid flow control device <NUM> may include a one-way fluid flow control device such as a check valve <NUM> to allow fluid (e.g., oil) to flow only or primarily in one direction through base <NUM> of the plunger <NUM>. In the example embodiment, the check valve <NUM> is housed in the base <NUM> of the plunger <NUM>, but other arrangements and locations for check valve <NUM> are not precluded. In any embodiment, the check valve <NUM> may be provided to allow fluid to flow easily behind the base <NUM> of the plunger <NUM>.

Fluid flow control device <NUM> also includes a spring <NUM> and a plug <NUM> coupled to the body <NUM> of the plunger <NUM>. The spring <NUM>, for example, may be configured to apply force onto the body <NUM> which may normally bias the plunger <NUM> of fluid flow control device <NUM> to a closed position, such as shown in <FIG>.

According to the example embodiment, the fluid flow control device <NUM> may be configured with a first chamber <NUM> and a second chamber <NUM> in fluid communication with one another through the check valve <NUM>. The first and second chambers <NUM> and <NUM> are configured to transfer fluid therebetween as the plunger moves to open and close the fluid flow path to the piston cooling nozzles <NUM>. For example, the second chamber <NUM> may receive fluid fed from the first chamber <NUM> through the check valve <NUM> in response to the fluid pressure increasing in the first chamber <NUM> as the engine speed increases.

According to an aspect of the present disclosure, the fluid flow control device <NUM> may be passively controlled to open and close in response to fluid pressure that is based on engine speed. In this case, the plunger <NUM> is configured to selectively open and close the fluid flow path between the fluid feed inlet <NUM> and piston cooling nozzles <NUM> in response to the engine speed being above or below a predetermined threshold. In <FIG>, 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 <NUM>. Thus, when the engine is not running or runs at a low engine speed, the plunger <NUM> is normally biased to a closed position in the fluid flow control device <NUM> and the check valve <NUM> 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 <NUM> from outlet <NUM>.

Referring to <FIG>, 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 <NUM> from the closed position toward an open position. The fluid pressure in the first chamber <NUM> acts on the end area of the body <NUM> to move the plunger <NUM> toward the open position (to the right in <FIG>. ) As the plunger <NUM> starts to move to the open position, the fluid pressure also opens the check valve <NUM> so that fluid flows into the second chamber <NUM>. The end area of the body <NUM> is greater than the area of the base <NUM> so the net force from the fluid pressure causes the plunger <NUM> to compress the spring <NUM>, overcoming a force biasing the plunger <NUM> to the closed position. In the example embodiment, fluid may flow from the first chamber <NUM> through the check valve <NUM> into the second chamber <NUM> as the plunger <NUM> moves from the closed position toward the open position so that the second chamber <NUM> fluid volume increases.

Referring to <FIG>, the plunger <NUM> is moved to the open position so that the fluid flow path is completely open by displacement of the plunger <NUM>. In the open position, the fluid flow path between the fluid feed inlet <NUM> and the piston cooling nozzles <NUM> is opened allowing fluid to freely flow from the fluid feed inlet <NUM> to the outlet <NUM> for feeding to the piston cooling nozzles <NUM>.

Referring to <FIG>, 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 <NUM> closes. In this case, the check valve <NUM> closes and substantially prevents fluid flow from the second chamber <NUM> into the first chamber <NUM> except through a controlled clearance <NUM> of the plunger <NUM>. Therefore, fluid may continue to flow to the piston cooling nozzles <NUM> even after the engine speed drops below the threshold that forces the plunger <NUM> to open.

According to an example embodiment, the fluid flow control device <NUM> may be configured with a clearance <NUM> that is provided on the check valve <NUM>. The clearance <NUM> provided on the check valve <NUM> may be a hole or passage that is sized to allow the fluid to slowly bleed from the second chamber <NUM> to the first chamber <NUM> even if the check valve <NUM> is closed so that the plunger <NUM> slowly returns to the closed position under the bias of the spring <NUM>.

In yet another example embodiment, the fluid flow control device <NUM> may be configured with a clearance provided on or around an area that is around the plunger <NUM>. For example, a clearance <NUM> may be provided around the base <NUM> between the wall of the cavity or the rifle that houses the plunger <NUM> and the base <NUM> so that fluid can flow from the second chamber <NUM> to the first chamber <NUM> even if the check valve <NUM> is closed.

With the clearance <NUM> provided in the check valve <NUM> or, alternatively or additionally around the base <NUM> of the plunger <NUM> (e.g., clearance <NUM>), the clearance <NUM> (and alternatively or additionally, the clearance <NUM>) is configured to allow fluid to bleed from the second chamber <NUM> into the first chamber <NUM> and the fluid feed inlet <NUM> to delay the closing of the fluid flow control device <NUM> 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 <NUM> allows the plunger <NUM> to return to the closed position slowly as oil evacuates the second chamber <NUM> and bleeds from the outlet <NUM> to the piston cooling nozzles <NUM> back into the inlet <NUM>. According to an aspect, for example, the slow return of the plunger <NUM> to the closed position keeps the fluid flow control device <NUM> 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>, another embodiment fluid flow control device <NUM> is provided that may be actuated by the intake manifold pressure and/or exhaust manifold pressure. Fluid flow control device <NUM> includes a plunger <NUM> housed in the fluid flow passage between the main fluid supply rifle <NUM> and the piston cooling nozzle <NUM> (see <FIG>). The plunger <NUM> may include a body <NUM> at one end and a base <NUM> at the other end. The plunger <NUM> includes a stem <NUM> that extends from one side <NUM> of the base <NUM> to the body <NUM> and separates the base <NUM> from the body <NUM>. At a side <NUM> of the base <NUM> opposite the one side <NUM>, the stem <NUM> extends through an opening <NUM> of the chamber <NUM> to an air pressure feed inlet <NUM> 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 <NUM> 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 <NUM> is configured to selectively open and close the fluid flow path between the fluid feed inlet <NUM> and piston cooling nozzles <NUM> in response to the engine speed being above or below a predetermined threshold. As the engine speed increases, air pressure from the inlet <NUM> increases to act on stem <NUM> in opening <NUM> and displace the plunger <NUM> to open the normally closed fluid flow path. As the engine speed decreases, the air pressure is reduced to allow the plunger <NUM> 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 <NUM> may include a one-way fluid flow control device such as check valve <NUM> to allow fluid (e.g., oil) to flow only or primarily in one direction through base <NUM> of the plunger <NUM>. In the example embodiment, the check valve <NUM> is housed in the base <NUM> of the plunger <NUM>, but other arrangements and locations for check valve <NUM> are not precluded. In any embodiment, the check valve <NUM> may be provided to allow fluid to flow easily behind the base <NUM> of the plunger <NUM>. Fluid flow control device <NUM> also includes a spring <NUM> and a plug <NUM> coupled to the body <NUM> of the plunger <NUM>. The spring <NUM>, for example, may be configured to apply force onto the body <NUM> which may normally bias the plunger <NUM> of fluid flow control device <NUM> 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.

Claim 1:
A piston cooling nozzle device (<NUM>) for controlling a flow of fluid used for cooling pistons in an internal combustion engine (<NUM>), the piston cooling nozzle device (<NUM>) comprising:
a fluid flow control device (<NUM>, <NUM>) configured to connect a fluid reservoir (<NUM>) and a piston cooling nozzle <NUM> for spraying the fluid onto a piston in the engine, the fluid flow control device (<NUM>, <NUM>) having a first chamber (<NUM>) that opens to allow the fluid to pass from the reservoir (<NUM>) to the piston cooling nozzle (<NUM>) in response to at least one of an engine speed and an air pressure exceeding a first threshold, the fluid flow control device (<NUM>, <NUM>) including a second chamber (<NUM>) in fluid communication with the first chamber (<NUM>) for receiving fluid fed from the first chamber (<NUM>) through a check valve (<NUM>, <NUM>) between the first and second chambers (<NUM>, <NUM>) in response to the fluid flow control device (<NUM>, <NUM>) being opened, wherein at least one of the fluid flow control device (<NUM>, <NUM>) and the check valve (<NUM>, <NUM>) includes a clearance (<NUM>, <NUM>) to bleed fluid from the second chamber (<NUM>) into the fluid reservoir (<NUM>) to delay a closing of the first chamber (<NUM>) of the fluid flow control device (<NUM>, <NUM>) for a predetermined period of time in response to the one of the engine speed and the air pressure dropping below the first threshold.