Patent Description:
The present disclosure relates generally to internal combustion engines, and more particularly, but not exclusively, to a pressure regulator for a lubrication system of the engine.

Generally, fluid flow control devices have been used in internal combustion engines to control the flow of oil and other fluids to provide lubrication and cooling of one or more components of the engine. For example, pressure regulators can be used to limit or prevent excessive pressure conditions in the lubrication circuit due to operation of the oil pump. However, current pressure regulators may perform in an unsatisfactory manner as a result of pulsed outlet flow from the pump. The pulsed outlet flow may cause uncontrolled cycling of the pressure regulator due to large changes in the oil pressure when the pressure regulator opens and discharges oil into the suction side of the pump. This may cause excessive noise, premature wear of the regulator spring, and rapid oscillations in the oil flow which may lead to oil pressure instability. As such, there exists a need for improvement in fluid flow control devices for lubrication and cooling of components in an internal combustion engine.

<CIT> discloses a relief valve includes a valve body having a first port through which fluid flows in and a second port through which the fluid is discharged, a sleeve arranged so as to be slidable within the valve body and formed with an inlet being communicatable with the first port and an outlet being communicatable with the second port, a valve being slidable within the sleeve by receiving a fluid pressure of the first port flowing through the inlet in order to establish a closing state at which the outlet is closed by the valve and an opening state at which the outlet is opened, a biasing member applying a biasing force to the valve and a valve position adjusting mechanism actuated for operating the fluid pressure of the first port so as to act on the sleeve in a direction of the biasing force of the biasing member and changing the position of the sleeve relative to the valve body by turning on or off the operation of the fluid pressure of the first port so as to act on the sleeve.

<CIT> discloses a filter bypass valve with piston which has a closure face closing off a cavity defined radially inwardly and downstream of an upstream end. The closure face is spaced from the upstream end by a first distance. The piston has a cavity extending in a downstream direction away from an opposed side of the closure face to a second end. A piston diameter is defined to an outer periphery of a cylindrical portion forming a seal face. A ratio of the piston diameter to the first distance is between <NUM> and <NUM>. A valve sleeve has windows formed to allow flow of fluid from a sleeve internal bore through the windows and to a downstream port. A ratio of the inner diameter to the axial dimension of the windows is between <NUM> and <NUM>. A ratio of the inner diameter to a circumferential dimension of the windows is between <NUM> and <NUM>.

The present disclosure includes a unique system and/or apparatus for regulating fluid flow in a lubrication circuit of an internal combustion engine. The lubrication system includes a reservoir from which fluid is fed and a pump for circulating fluid through the lubrication circuit of the engine. The lubrication system includes a fluid flow control device at the outlet side of the pump that regulates pressure conditions output from the pump upstream of the lubrication circuit in the engine. In one embodiment, the fluid flow control device includes a first chamber that opens in response a fluid pressure exceeding a threshold to allow the fluid to pass from the outlet side of the pump back to the suction or inlet side of the pump. The fluid flow control device also includes at least one elongated aperture in communication with the chamber for receiving fluid fed from the chamber and allowing the fluid in the chamber to flow to the inlet side of the pump.

The invention includes a fluid flow control device for regulating a pressure in a lubrication circuit in an internal combustion engine. The fluid flow control device includes an elongated body having an opening at a first end of the body, and a chamber extending from the first end of the body to a second end of the body. The elongated body includes a number of axially elongate apertures (one or more) along its perimeter that open into the chamber and at an exterior of the elongated body. The aperture(s) allow fluid in the chamber to flow to an inlet side of the pump. The fluid is admitted into the chamber by a spring loaded valve member in the first end opening that is configured to crack open in response to the outlet pressure of the fluid from pump exceeding a predetermined threshold.

In a first aspect, the invention provides a flow control device, as set out in claim <NUM> appended hereto.

In a second aspect the invention provides a lubrication system for an internal combustion engine, as set out in claim <NUM> appended hereto.

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.

The present disclosure relates to a lubrication system for an internal combustion engine having a mechanically controlled fluid flow control device configured to open when a fluid pressure in a lubrication circuit exceeds a threshold pressure. In an embodiment, referring to <FIG>, the lubrication system <NUM> includes a fluid flow control device <NUM> that is, for example, a pressure regulator valve <NUM>, positioned downstream of the lubrication fluid pump <NUM> and upstream of the lubrication fluid filter <NUM> of the engine <NUM>. Lubrication system <NUM> further includes a rifle <NUM> that provides lubrication fluid flow path to a plurality of engine components <NUM> and/or other rifles (not shown) for distribution about various components and locations relative to the engine <NUM>. The lubrication fluid returns to a reservoir such as a sump <NUM> at or near the inlet or suction side of pump <NUM>. It should be understood that not all components or aspects of a lubrication system are illustrated, and system <NUM> may be configured according to any known engine fluid lubrication system that incorporates the inventive fluid flow control device <NUM> of the present disclosure. Furthermore, while the lubrication fluid may be engine oil according to one embodiment, other types of fluids and fluid circuits are also contemplated in which the fluid flow control device <NUM> may be employed.

The pressure regulator valve <NUM> is located at the outlet side of lubrication fluid pump <NUM> and controls a pulsed output flow from the pump <NUM> by opening when the lubrication fluid pressure exceeds a threshold pressure. Opening of pressure regulator valve <NUM> recirculates lubrication fluid back to the inlet side of pump <NUM>. As discussed further below, the pressure regulator valve <NUM> includes at least one elongated aperture for recirculation of the lubrication fluid that slows the displacement of the plunger of the pressure regulator valve <NUM> as the plunger progressively opens the elongated aperture for lubrication fluid recirculation. As a result, pulsed output flow of lubrication fluid from the pump <NUM> is smoothed and oscillations in the lubrication fluid are reduced. The fluid flow control device <NUM> disclosed herein provides progressive opening and closing of the recirculation path, which allows placement of the pressure regulator device close to the outlet of pump <NUM>, such as within about <NUM> millimeters of the pump outlet. Other embodiments contemplate other distances depending on the parameters and requirements for the lubrication system. Furthermore, the system <NUM> does not require a separate bypass valve for the lubrication fluid during cold start conditions, and does not require the use of a pressure relief valve in the system <NUM>.

Referring to <FIG>, an embodiment of the fluid flow control device <NUM> is shown in a recirculation flow path <NUM> in fluid communication with the rifle <NUM> at the outlet side of pump <NUM> and upstream of filter <NUM>. Flow path <NUM> includes a flow of fluid from the sump <NUM> that is drawn by the pump <NUM> as indicated by arrow <NUM>, a flow to the engine <NUM> from the pump outlet as indicated by arrow <NUM>, and a regulated flow through the fluid flow control device <NUM> when the fluid flow control device <NUM> is open as indicated by arrows <NUM>.

Fluid flow control device <NUM> includes an elongated body <NUM> defining a chamber <NUM> that has an opening <NUM> at a first end <NUM> of body <NUM>. Chamber <NUM> is closed at an opposite second end <NUM> of body <NUM>. Body <NUM> includes at least one elongated aperture, such as opposite elongated apertures 54a, 54b, in fluid communication with chamber <NUM> and exterior side of body <NUM>. Other embodiments contemplate a single elongated aperture <NUM>, or more than two elongated apertures, or one or more elongated apertures in combination with one or more apertures having a different shape. If multiple elongated apertures are provided, they need not be directly opposite one another. In the illustrated embodiment, aperture(s) <NUM> include a racetrack shape extending along the longitudinal axis of body <NUM>. Other shapes are also contemplated, such as oval shapes, that provide a controlled opening to relieve pressure in response to an oscillating pressure input.

Apertures 54a, 54b allow lubrication fluid entering opening <NUM> to flow from chamber <NUM> to an exterior of body <NUM>. In one embodiment, the opening <NUM> is located at the first end <NUM> of body <NUM> and is in fluid communication with recirculation flow path <NUM> and chamber <NUM> when fluid flow control device <NUM> is opened in response to pressure conditions at the outlet side of pump <NUM> exceeding a threshold. Other embodiments contemplate opening <NUM> may be located in a side wall of body <NUM> adjacent to first end <NUM>. Apertures 54a, 54b are in fluid communication with chamber <NUM> and inlet side <NUM> of pump <NUM> to allow recirculation of the lubrication fluid when the fluid flow control device is opened in response to pressure conditions exceeding a threshold pressure.

In the example embodiment, the fluid flow control device <NUM> may include a plunger <NUM> housed in chamber <NUM> adjacent opening <NUM>. As shown in <FIG>, the plunger <NUM> is passively controlled to move into chamber <NUM> to open and close recirculation flow path <NUM> between the outlet side of pump <NUM> and the inlet side of pump <NUM> in response to a pressure condition exceeding a pressure threshold, such as a cracking pressure, sufficient to overcome the biasing closing force of spring <NUM> and displace plunger into chamber <NUM> along the apertures 54a, 54b, as shown by plunger <NUM>'. As the pressure increases, the more plunger <NUM> is displaced progressively along apertures 54a, 54b, providing additional open area for fluid flow via apertures 54a, 54b as shown by plunger <NUM>". As the pressure decreases, the spring <NUM> returns the plunger <NUM> toward its normally closed position and closes the fluid flow path when the pressure drops below the pressure threshold, as shown by plunder <NUM>. In the closed position, lubrication fluid cannot flow through fluid flow control device <NUM> to the inlet side of pump <NUM>.

The plunger <NUM> may include a base <NUM> at one end thereof with base <NUM> located in chamber <NUM>. Plunger <NUM> may also include a stem <NUM> extending outwardly from base <NUM> through end opening <NUM> at the first end <NUM> of body <NUM>. Stem <NUM> can extend into a passage <NUM> in the engine block or other structure for guiding movement of plunger <NUM>. Spring <NUM> can be received in and contact base <NUM>. Spring <NUM> extends from the based <NUM> and contacts the second end <NUM> of body <NUM> in chamber <NUM>.

Referring to <FIG>, the body <NUM> is elongated and cylindrical from the opening <NUM> at its first end <NUM> to second end <NUM>. Second end <NUM> can include a flange <NUM> for engagement with a tool for the insertion and removal of body <NUM> from the engine block. Body <NUM> may also define threads <NUM> adjacent second end <NUM> for threaded engagement with the engine block.

Body <NUM> may also include a circumferential groove <NUM> adjacent first end <NUM> for receipt of an O-ring seal to seal the exterior of body <NUM> around first end <NUM> from the recirculation fluid flow <NUM>. Body <NUM> also includes an elongated grooved portion <NUM> around apertures 54a, 54b that form a recess in body <NUM> around apertures 54a, 54b, allowing lubrication fluid to exit chamber <NUM> for recirculation.

Chamber <NUM> includes a reduced diameter portion <NUM> adjacent second end <NUM> that extends to a blind end <NUM> of chamber <NUM>. The spring <NUM> abuts second end <NUM> at blind end <NUM>. A hole <NUM> is provided in body <NUM> in communication with chamber <NUM> to assist in maintaining pressure balance in chamber <NUM> as plunger <NUM> moves back and forth in chamber <NUM>. Hole <NUM> allows fluid to move in and out of the rear part of chamber <NUM> (behind plunger <NUM>) to prevent hydraulic lock.

Further written description of a number of example aspects of the present disclosure and embodiments thereof shall now be provided. It should be appreciated that any combination of one or more of the embodiments is contemplated.

According to one aspect of the present disclosure, a lubrication system for an internal combustion engine includes a reservoir from which fluid is fed by a pump for circulation through the lubrication system via a fluid flow path. A flow control device is coupled to the fluid flow path downstream of an outlet side of the pump. The flow control device includes an elongated body defining a chamber extending from a first end of the body toward a second end of the body, a plunger at the first end of the body configured to normally close the chamber at the first end of the body and to displace into the body to admit fluid into the chamber in response to a fluid pressure in the fluid flow path exceeding a threshold. At least one elongated aperture along the body allows fluid to flow from the chamber to an inlet side of the pump as the plunger is displaced into the body.

In an embodiment, the plunger is spring-loaded and is movable to selectively open and close the chamber from the fluid flow path. In an embodiment, the plunger includes a base oriented toward the first end and a stem extending from the base toward the second end of the body.

In an embodiment, the at least one elongated aperture is two elongated apertures. In an embodiment, the two elongated apertures are located on opposite sides of the body.

In an embodiment, the at least one elongated aperture is racetrack-shaped in that it is rectangular along opposite sides and has circular ends, with the elongated sides extending along a longitudinal axis of the body. In an embodiment, the at least one elongated aperture is located closer to the first end of the body than the second end of the body.

In an embodiment, the at least one elongated aperture extends from a first end of the at least one elongated aperture oriented toward the first end of the body to an opposite second end of the at least one elongated aperture and, as the plunger is moved into the body to admit fluid into the chamber, the plunger moves along the at least one elongated aperture from the first end toward the second end to progressively expose the at least one elongated aperture to the fluid admitted into the chamber for circulation to the inlet side of the pump through an exposed part of the at least one elongated aperture.

In an embodiment, the body defines a grooved portion that forms a recess in an exterior of the body around the at least one elongated aperture. In an embodiment, the body includes a flange at the second end of the body and an exterior threaded portion that is located adjacent the flange. In an embodiment, the chamber extends to a blind end adjacent the second end of the body.

In an embodiment, the body includes a hole extending therethrough adjacent the second of the body. In an embodiment, the fluid flow control device is located with on the outlet side of the pump.

According to another aspect of the present disclosure, a flow control device for controlling a pressure in a fluid flow path of an internal combustion engine is provided. The flow control device includes an elongated cylindrical body defining a chamber extending from a first end of the body toward a second end of the body. A plunger at the first end of the body is configured to normally close the chamber at the first end of the body and to displace into the body to admit fluid into the chamber in response to the pressure in the fluid flow path exceeding a threshold. At least one elongated aperture along the body opens into the chamber and at an exterior side of the body to allow fluid flow therethrough in response to the plunger being displaced into the body.

In one embodiment, the plunger is spring-loaded and is movable to selectively open and close the chamber from the fluid flow path. In one embodiment, the at least one elongated aperture is two elongated apertures located on opposite sides of the body.

In one embodiment, the at least one elongated aperture extends from a first end of the at least one elongated aperture oriented toward the first end of the body to an opposite second end of the at least one elongated aperture. As the plunger is moved into the body to admit fluid into the chamber, the plunger moves along the at least one elongated aperture from the first end toward the second end to progressively expose the at least one elongated aperture to the fluid admitted into the chamber for circulation through an exposed part of the at least one elongated aperture.

Claim 1:
A flow control device (<NUM>) for controlling a pressure in a fluid flow path (<NUM>) of an internal combustion engine (<NUM>), comprising:
an elongated cylindrical body (<NUM>) defining a chamber (<NUM>) extending from a first end (<NUM>) of the body toward a second end (<NUM>) of the body (<NUM>), a plunger (<NUM>) at the first end of the body (<NUM>) configured to normally close the chamber (<NUM>) at the first end (<NUM>) of the body (<NUM>) and to displace into the body (<NUM>) to admit fluid into the chamber (<NUM>) in response to the pressure in the fluid flow path (<NUM>) exceeding a threshold, and at least one elongated aperture (54a, 54b) extending along a longitudinal axis of the body (<NUM>) that opens into the chamber (<NUM>) and at an exterior side of the body (<NUM>), the at least one elongated aperture (54a, 54b) being configured to slow displacement of the plunger (<NUM>) as the plunger (<NUM>) progressively opens the at least one elongated aperture (54a, 54b) to allow fluid flow from the chamber (<NUM>) therethrough in response to the plunger (<NUM>) being displaced into the body (<NUM>).