VCT valve with reed check

Abstract

A variable camshaft timing (VCT) control valve assembly includes a control valve having one or more valve faces and a valve cavity, one or more cavity vent ports in the control valve configured to communicate fluid between an outer surface of the control valve and the valve cavity, a valve sleeve having a sleeve cavity to receive the control valve and a plurality of holes, at least one of the holes configured to be in fluid communication with an advance fluid chamber of a VCT device and another one of the holes configured to be in fluid communication with a retard fluid chamber, the control valve axially slidable relative to the valve sleeve, and one or more reed valves attached to an outer surface of the valve sleeve configured to control fluid flow between one of the advance fluid chamber or the retard fluid chamber and the other of the advance fluid chamber or the retard fluid chamber.

Description

Technical Field

[0001] This application relates to variable camshaft timing (VCT), and more specifically, to a check valve used with a VCT device. Background Technology

[0002] Internal combustion engines use one or more camshafts to open and close intake and exhaust valves in response to the cam lobe angle selectively braking the valve stem as the camshaft rotates, overcoming the force of the valve spring that holds the valve in place. The shape and angular position of the cam lobe angle can affect the operation of an internal combustion engine. In the past, the angular position of the camshaft relative to the crankshaft was fixed. However, internal combustion engines can now include a variable camshaft timing (VCT) device—sometimes called a camshaft phaser—which changes the angular position of the camshaft relative to the crankshaft. Camshaft phasers are typically hydraulically actuated and include a rotor with radially outward-extending blades located in fluid chambers formed within the stator. The camshaft phaser can rely on a control valve assembly that selectively directs fluid into portions of the fluid chambers separated by the blades to apply rotational force to the rotor, thereby creating relative motion between the rotor and the stator. One or more check valves can be used to control the flow of fluid. However, the addition of check valves can increase the overall size of the assembly. Including one or more check valves in the assembly while minimizing the overall size of the control valve assembly would be helpful. Summary of the Invention

[0003] In one embodiment, a variable camshaft timing (VCT) control valve assembly includes: a control valve having one or more valve faces and valve chambers; an exhaust port configured in one or more chambers of the control valve to communicate fluid between an outer surface of the control valve and the valve chambers; a valve sleeve having a cavity for receiving the control valve and a plurality of orifices, at least one of the orifices being configured to communicate fluidly with a forward fluid chamber of the VCT device, and another of the orifices being configured to communicate fluidly with a delayed fluid chamber; the control valve being axially slidable relative to the valve sleeve; and one or more reed valves on the outer surface of the valve sleeve, configured to control fluid flow between one of the forward fluid chambers or the delayed fluid chambers and the other of the forward fluid chambers or the delayed fluid chambers.

[0004] In another embodiment, a VCT control valve assembly includes: a control valve having one or more valve faces and a valve cavity; one or more chamber vents configured to communicate fluid between an outer surface of the control valve and the valve cavity; a valve sleeve having a cavity for receiving the control valve and a plurality of orifices, at least one of the orifices being configured to communicate fluidly with a forward fluid chamber of a VCT device, and another of the orifices being configured to communicate fluidly with a delayed fluid chamber; the control valve being axially slidable relative to the valve sleeve; a first reed valve on the outer surface of the valve sleeve configured to control fluid flow between the forward fluid chamber and the delayed fluid chamber; and a second reed valve on the outer surface of the valve sleeve configured to control fluid flow between the delayed fluid chamber and the forward fluid chamber.

[0005] In another embodiment, a VCT control valve assembly includes: a control valve having one or more valve faces and a valve cavity; one or more cavity vents configured to communicate fluid between an outer surface of the control valve and the valve cavity; a valve sleeve having a cavity receiving the control valve, an annular groove on an outer surface of the valve sleeve, a plurality of orifices configured to communicate fluid between the cavity and the outer surface of the valve sleeve, and a flat seat surface on the outer surface of the valve sleeve; and a reed valve received by the annular groove, the reed valve including a flat section biased to engage with the flat seat surface to releasably seal the orifices and allow fluid to flow from one of a forward fluid chamber or a delayed fluid chamber to the other of the forward fluid chamber or delayed fluid chamber. Attached Figure Description

[0006] Figure 1 This is a schematic diagram depicting an implementation of the VCT device;

[0007] Figure 2 This is another schematic diagram depicting an implementation of the VCT device;

[0008] Figure 3 This is another schematic diagram depicting an implementation of the VCT device;

[0009] Figure 4 This is a perspective view depicting an embodiment of the VCT control valve assembly;

[0010] Figure 5 This is an exploded view depicting an implementation of the VCT control valve assembly;

[0011] Figure 6 This is a cross-sectional view depicting an embodiment of the VCT control valve assembly;

[0012] Figure 7 This is another cross-sectional view depicting an embodiment of the VCT control valve assembly;

[0013] Figure 8 This is a perspective view depicting another embodiment of the VCT control valve assembly;

[0014] Figure 9 This is a cross-sectional view illustrating another embodiment of the VCT control valve assembly; and

[0015] Figure 10 This is a cross-sectional view illustrating another embodiment of the VCT control valve assembly. Detailed Implementation

[0016] Control valve assemblies used with variable camshaft timing (VCT) devices include one or more reed valves located on the outer surface of the valve sleeve, which serve as check valves for hydraulic VCT devices. In past control valve implementations, check valves in the form of ball or disc valves were positioned within the control valve chamber, increasing the axial length and complexity of the control valve assembly. Valves located within the control valve chamber include more parts, are typically press-fitted into the chamber, and may require flow testing to validate their seat geometry. Conversely, positioning the reed check valve away from the control valve chamber and on the outer surface of the valve sleeve can be achieved as part of an outer surface machining already performed on the valve sleeve, reducing the overall length of the control valve assembly.

[0017] An embodiment of a variable camshaft timing (VCT) device or phaser 10 and a VCT control valve assembly 12 is shown in the accompanying drawings and described in detail in this specification. The VCT phaser 10 and VCT control valve assembly 12 are typically mounted in automotive internal combustion engine applications. The VCT control valve 12 can be mounted at a location in the accompanying internal combustion engine at the center bolt position of the VCT housing and rotor. The VCT control valve assembly 12 is capable of performing torsion assist (TA) and camshaft torque actuation (CTA) phasing functions, which are distinct from and concurrent with those of the VCT control valve assembly disclosed herein. Furthermore, as used herein, the terms axial, radial, and circumferential, and their associated grammatical forms, are used to refer to the generally circular and cylindrical shape of some components of the illustrated control valve and its parts. In this sense, axial refers to a direction generally along or parallel to the central axis of the circle and cylinder, radial refers to a direction generally along or parallel to the radius of the circle and cylinder, and circumferential refers to a direction generally along or similar to the circumference of the circle and cylinder.

[0018] refer to Figures 1-3The VCT phaser 10 is a hydraulically actuated VCT phaser assembly and typically includes a VCT control valve assembly 12, a rotor 14, and a housing 16. The rotor 14 has a hub 18 and one or more blades 20 extending radially outward from the hub 18. The rotor 14 is connected to a camshaft 22 such that rotation of the rotor 14 causes rotation of the camshaft 22. The housing 16 may have a camshaft sprocket 24 or pulley and partially establishes a forward fluid chamber 26 and a delayed fluid chamber 28 with the rotor 14. An annular ring, such as a chain or belt, engages the camshaft sprocket 24 or pulley and further engages a crankshaft sprocket or other components associated with the internal combustion engine. Through engagement, rotation is transmitted from the internal combustion engine to the housing 16, causing the housing 16 to rotate as well. The blades 20 occupy the forward fluid chamber 26 and the delayed fluid chamber 28, and during use of the VCT phaser assembly 10, the fluid chambers 26, 28 receive pressurized fluid via their respective forward lines 30 and delayed lines 32. Among other possible components of the VCT phaser assembly 10, the VCT phaser assembly 10 may further include a locking pin assembly 34, an actuator 36 such as a variable force solenoid (VFS) actuator, and a controller 38 such as an engine control unit (ECU). The locking pin assembly 34 is used to maintain the angular position of the rotor 14 relative to the housing 16. Generally, the actuator 36 acts on the control valve 40 of the VCT control valve assembly 12 and moves the control valve 40 axially and linearly against the bias of the spring 42 and according to the instructions of the controller 38. Similarly, as... Figure 1-3 As schematically depicted, hydraulic fluid, such as oil, is selectively introduced into the VCT control valve assembly 12 via a source 44 associated with the internal combustion engine. Source 44 may be pressurized by a pump. Furthermore, at certain times, the oil may exit the VCT control valve assembly 12 and reach an oil sump or tank 46 associated with the internal combustion engine. While exemplary applications of the VCT control valve assembly 12 have now been described, the VCT control valve assembly 12 can be used in other applications, including those with different characteristics. Figures 1-3 Applications of other VCT phaser assemblies shown and described with reference to their components and operating methods.

[0019] To enable the forward and delayed functions of the VCT phaser assembly 10, the VCT control valve assembly 12 helps manage the flow of oil into and out of the forward fluid chamber 26 and the delayed fluid chamber 28. Depending on the specific internal combustion engine application in which the VCT control valve assembly 12 is used, the VCT control valve assembly 12 can have various designs, configurations, and components. In the embodiment shown in the figures, the VCT control valve assembly 12 is designed and configured to perform torsion assist (TA) and camshaft torque actuation (CTA) phasing functions. The VCT control valve 12 typically includes a valve housing 48, a control valve 40, an inlet check valve 41, a first recirculation check valve 50, a second recirculation check valve 52, a first recirculation path 54, and a second recirculation path 56; however, in other embodiments, more or fewer and / or different components are possible.

[0020] Figures 4-7 An embodiment of the VCT control valve assembly 12 is shown in more detail. Assembly 12 includes a control valve 58, a valve sleeve 60 slidably receiving the control valve 58, and a supply check valve 62 located at one end of assembly 12. A center bolt housing 64 receives the VCT control assembly 12 and extends through the axis of rotation of a hydraulically actuated VCT phaser 10 to secure the phaser 10 to the camshaft 22 of the internal combustion engine. The control valve 58 may be an elongated piston having a generally annular shape and one or more valve faces 66 extending radially outward from the valve 58, which facilitate control of fluid flow through the valve 58 and the sleeve 60. The control valve 58 may include a valve cavity 68 such that the radial interior of the valve 58, coinciding with the axis of rotation of the camshaft, is hollow. Two pairs of cavity vents 70 allow fluid to flow from the outer surface 72 of the control valve 58 into the valve cavity 68. It should be understood that the number of cavity vents can vary, and the embodiment shown and described is one. Here, when fluid flows into the delayed fluid chamber 28, a plurality of chamber vents 70 receive fluid from the forward fluid chamber 26, while when fluid flows into the forward fluid chamber 26, a second plurality of chamber vents 70 receives fluid from the delayed fluid chamber 28. However, each plurality of chamber vents can be replaced by a single chamber vent receiving fluid from the forward fluid chamber 26 and a single chamber vent receiving fluid from the delayed fluid chamber 28. The end 74 of the control valve 58 can be configured to couple to an actuator 36 (e.g., a solenoid) that moves the valve 58 relative to the sleeve 60. The outer diameter 76 of the valve face 66 can tightly conform to the inner surface 78 of the sleeve 58 to prevent axial flow of fluid between adjacent valve faces 66.

[0021] The valve sleeve 60 may be an elongated tube having a cavity 69 that receives the control valve 58 at an open end 90. A plurality of orifices 61 may be formed in the valve sleeve 60, extending between the cavity 69 and the outer surface of the sleeve 60. The orifices 61 may form at least a portion of a first recirculation path 54, a second recirculation path 56, a first recirculation check valve 50, or a second recirculation check valve 52. A cavity vent 70 may communicate return fluid from the forward fluid chamber 26 or the delayed fluid chamber 28 to the tank 46. The control valve 58 may be biased to a default position by a spring 42 located between the valve 58 and the sleeve 60 within the cavity 69, biasing the valve 58 in one axial direction. A retaining ring 43 releasably engages with a center bolt housing 64 and helps to hold the control valve 58 in the default position. The control valve 58 can be axially moved relative to the valve sleeve 60 by the actuator 36, thereby overcoming the force of the spring 42 to selectively guide fluid through the orifice 61 and control the flow of fluid into the forward fluid chamber 26 or the delayed fluid chamber 28. For example, the valve sleeve 60 can be formed of various metals or metal alloys. The outer surface of the valve sleeve 60 can be formed, for example, by machining to form a valve seat surface 80. In this embodiment, the outer surface of the valve sleeve 60 can be machined into two substantially flat surfaces 80. The flat surfaces 80 can be oriented 180° apart in opposite directions. The outer surface of the valve sleeve 60 can also be shaped to form at least one annular groove 82, the shape of which is adapted to receive a reed check valve or reed valve 84. The term reed valve can also be described as a baffle valve, a half-band valve, a semi-band valve, or other similar terms. A reed valve may include a flat section that is relatively biased to engage with an orifice through which fluid can flow. In some embodiments, the reed valve may completely surround the valve sleeve, such that the flat section overlaps itself; however, in other embodiments, the reed valve may contact the valve sleeve at less than 360 degrees. Reed valves are typically implemented where their spring force is integrated with the valve components.

[0022] The reed valve 84 may include two substantially flat sections 86 biased to engage with a valve seat formed by a flat surface 80, thereby forming a fluid-tight seal. The flat sections 86 may have the same width as the reed valve material of the valve 84 connecting the two sections 86. Fluid exiting the orifice 61 covered by the flat sections 86 overcomes the biasing force holding the flat sections 86 against the flat surface 80, and prevents fluid from moving in the opposite direction through the orifice 61 when the flat sections 86 press against the flat surface 80, further enhancing the fluid-tight seal. The reed valve 84 can be implemented in various ways, for example, by using a strip check valve or a substantially flat material section hinged at one edge. In this embodiment, the reed valve 84 may be formed from an elongated flat metal that can be bent and / or folded using metalworking techniques, such that the reed valve 84 fits tightly against the outer surface of the valve sleeve 60. The bending of the reed valve 84 can apply an inherent biasing force that clamps the reed valve 84 onto the valve sleeve 60 in the annular groove 82.

[0023] A supply check valve 62 can be attached to a valve sleeve 60 at a position opposite to the open end 90. The supply check valve 62 can regulate the fluid supply from a source 44 (e.g., an engine oil pump) to the VCT control valve assembly 12. The supply check valve 62 may include a sleeve engagement portion 92 and a center bolt engagement section 94 that mechanically connects the valve 62 to the sleeve 60 and the center bolt housing 64. Features 92, 94 prevent angular rotation of the supply check valve 62 relative to the sleeve 60 and the center bolt housing 64 and facilitate precise angular positioning of these components relative to each other. The supply check valve 62 can selectively allow fluid to flow from the source 44 to the outer surface of the valve sleeve 60, where fluid can flow through a selected orifice 61 based on the axial position of the control valve 58 relative to the valve sleeve 60.

[0024] The center bolt housing 64 may include a housing cavity 96 for receiving the VCT control valve assembly 12. A forward fluid port 98 and a delayed fluid port 100 allow fluid to pass from the outer surface of the control valve 58 through a port 61 and ultimately into the forward fluid chamber 26 and the delayed fluid chamber 28, respectively. One or more openings 102 at the axial end of the center bolt housing 64 may receive the center bolt engagement section 94. The center bolt housing 64, together with the VCT control valve assembly 12, can be inserted through the center of the rotor 14 into the hydraulically actuated VCT phaser 10.

[0025] During operation, such as Figure 6As shown, when the control valve 58 is positioned relative to the valve sleeve, the VCT control valve assembly 12 can guide fluid to the forward fluid chamber 26. Fluid can move along the outer surface of the valve sleeve 60 through the supply check valve 62, flowing from the outer surface of the valve sleeve 60 through the orifice 61 to the outer surface 72 of the control valve 58. The first recirculation check valve 50 can be closed, helping to guide fluid from the outer surface 72 of the control valve 58 through the orifice 61 and the forward fluid orifice 98 in the valve sleeve 60 to the forward fluid chamber 26. Fluid leaving the delay fluid chamber 28 can flow through the delay fluid orifice 100 to the valve sleeve 60, through the orifice 61 to the outer surface 72 of the control valve 58, and through the first pair of chamber vents 70 to the valve chamber 68, where fluid can exit the control valve 58 and reach the housing 46. When the fluid pressure leaving the delay chamber 28 exceeds the fluid pressure from the source 44, fluid from the first plurality of vents 70 can open the first recirculation check valve 50, which separates the reed valve 84 from the valve seat, and ultimately flow into the forward fluid chamber 26.

[0026] When control valve 58 is positioned relative to the valve sleeve, such as Figure 7 As shown, fluid can move along the outer surface of valve sleeve 60 through supply check valve 62, flowing from the outer surface of valve sleeve 60 to the outer surface 72 of control valve 58. The second recirculation check valve 52 can remain closed, helping to guide fluid from the outer surface 72 of control valve 58 through orifice 61 and delay fluid orifice 100 in valve sleeve 60 to delay fluid chamber 28. Fluid leaving advance fluid chamber 26 can flow through advance fluid orifice 98 to valve sleeve 60 and through orifice 61 to the outer surface 72 of control valve 58. Fluid leaving advance fluid chamber 26 can flow through valve chamber 68 through second pair of chamber outlets 70, where fluid can exit the second recirculation check valve 52 and / or second pair of chamber outlets 70 and reach tank 46. When the fluid pressure leaving advance chamber 26 exceeds the fluid pressure from source 44, fluid from the second plurality of vents 70 can open the second recirculation check valve 52, which separates reed valve 84 from its seat, and ultimately flow into delay fluid chamber 28.

[0027] Go to Figures 8-10This illustrates another embodiment of the VCT control valve assembly 12'. Assembly 12' includes a control valve 58', a valve sleeve 60' slidably receiving the control valve 58', and a supply check valve 62 located at one end of assembly 12'. The control valve 58' includes a pair of chamber vents 70 for recirculating fluid when fluid flows into the forward fluid chamber 26 and out of the delayed fluid chamber 28, and vice versa. The valve sleeve 60' includes a single recirculation reed check valve 84'. A center bolt housing 64 may receive the VCT control assembly 12' and extends through the axis of rotation of a hydraulically actuated VCT phaser 10 to secure the phaser 10 to the camshaft 22 of the internal combustion engine. The control valve 58' may be an elongated piston having a generally annular shape and one or more valve faces 66 extending radially outward away from the valve 58, the valve faces 66 facilitating control of fluid flow through the valve 58' and the sleeve 60'. The control valve 58' may include a valve chamber 68 such that the radial interior of the valve 58, which coincides with the rotation axis (x) of the camshaft, is hollow. A single pair of chamber vents 70 may allow fluid to flow from the outer surface 72 of the control valve 58 into the valve chamber 66 when fluid flows into the forward fluid chamber 26 and out of the delayed fluid chamber 28, or when fluid flows into the delayed fluid chamber 28 and out of the forward fluid chamber 26. That is, all chamber vents 70 in the control valve 58 may be used simultaneously during the phasing or movement of fluid entering or exiting chambers 26, 28. Furthermore, although this embodiment depicts two chamber vents 70, a different number of chamber vents are also possible. The end 74 of the control valve 58 may be configured to connect to a linear actuator (e.g., a solenoid) that moves the valve 58' relative to the sleeve 60'.

[0028] The valve sleeve 60' may be an elongated tube having a cavity 69 that receives the control valve 58' at an open end 90. One or more orifices 61 may be formed in the valve sleeve 60', extending between the cavity 69 and the outer surface of the sleeve 60'. The orifices 61 may form at least a portion of a first recirculation path 54, a second recirculation path 56, a first recirculation check valve 50, or a second recirculation check valve 52. A cavity vent 70 may communicate return fluid from the forward fluid chamber 26 or the delayed fluid chamber 28 to the tank 46. The control valve 58 may be biased to a default position by a spring 42 located between the valve 58 and the sleeve 60 within the cavity 69 to bias the valve 58' in one axial direction. A retaining ring 43 releasably engages with a center bolt housing 64 and helps to hold the control valve 58' in the default position. The control valve 58' can be axially moved relative to the valve sleeve 60' by the actuator 36, thereby overcoming the force of the spring 42 to selectively guide fluid through the orifice 61 and control the flow rate into the forward fluid chamber 26 or the delayed fluid chamber 28. The outer surface of the valve sleeve 60' can be machined, for example, to form a valve seat surface 80. In this embodiment, the outer surface of the valve sleeve 60' can be machined into two substantially flat surfaces 80. The flat surfaces 80 can be oriented 180° apart in opposite directions. The outer surface of the valve sleeve 60' can also be shaped to form an annular groove 82, the shape of which is adapted to receive a reed check valve or a reed valve 84'.

[0029] The reed valve 84' may include two substantially flat sections 86', the width or surface area of ​​which is greater than the portion connecting the two sections 86'. The flat sections 86' may be biased to engage with a valve seat formed by the flat surface 80, thereby forming a fluid-tight seal. Fluid exiting the orifice 61 covered by the flat sections 86' can overcome the biasing force holding the flat sections 86' against the flat surface 80, and when the flat sections 86' press against the flat surface 80, prevent fluid from moving in the opposite direction through the orifice 61, further enhancing the fluid-tight seal. The reed valve can be implemented in various ways, for example, by using a strip check valve or a substantially flat material section hinged at one edge. In this embodiment, the reed valve 84 may be formed from an elongated piece of flat metal that can be stamped and bent and / or folded using metalworking techniques, such that the reed valve 84 fits tightly against the outer surface of the valve sleeve 60. The bending of the reed valve 84' can apply an inherent biasing force that clamps the reed valve 84' onto the valve sleeve 60' in the annular groove 82. A supply check valve 62 can be attached to the valve sleeve 60' at a position opposite the open end 90. As described above, the supply check valve 62 can regulate the fluid supply from the source 44 (e.g., an engine oil pump) to the VCT control valve assembly 12'.

[0030] The center bolt housing 64 may include a housing cavity 96 for receiving the VCT control valve assembly 12'. A forward fluid port 98 and a delayed fluid port 100 allow fluid to pass from the outer surface of the control valve 58' through a port 61 and ultimately into the forward fluid chamber 26 and the delayed fluid chamber 28, respectively. An opening 102 at the axial end of the center bolt housing 64 can receive the center bolt engagement section 94. The center bolt housing 64, together with the VCT control valve assembly 12', can be inserted through the center of the rotor 14 into the hydraulically actuated VCT phaser 10.

[0031] During operation, when the control valve 58' is positioned relative to the valve sleeve 60', such as Figure 9 As shown, the VCT control valve assembly 12' directs fluid to the forward fluid chamber 26. Fluid can flow along the outer surface of the valve sleeve 60' past the supply check valve 62, from the outer surface of the valve sleeve 60' to the outer surface 72 of the control valve 58', entering through orifice 61. Fluid can then flow through another orifice 61 into the forward fluid orifice 98, flowing towards the forward fluid chamber 26. Fluid leaving the delay fluid chamber 28 can flow through the delay fluid orifice 100 and orifice 61 to the outer surface 72 of the control valve 58'. When the fluid pressure from the delay fluid chamber 28 is greater than the fluid pressure supplied by the source 44, the reed valve 84' can open. This facilitates the return of fluid from the delay fluid chamber 28 to the forward fluid chamber 26, while also allowing fluid to enter the valve chamber 68 from the outer surface 72 of the control valve 58 through the chamber vent 70. In the valve chamber 68, fluid can flow out of the open end of the sleeve 60' and into the housing 46.

[0032] When control valve 58 is positioned relative to valve sleeve 60', such as Figure 10 As shown, fluid can flow along the outer surface of valve sleeve 60' past supply check valve 62, from the outer surface of valve sleeve 60' to the outer surface 72 of control valve 58', and into orifice 61. Then, fluid can flow through another orifice 61 into delay fluid orifice 100, reaching delay fluid chamber 28. Fluid leaving advance fluid chamber 26 can flow through advance fluid orifice 98 and orifice 61 to the outer surface 72 of control valve 58'. When the fluid pressure from advance fluid chamber 26 is greater than the fluid pressure supplied by source 44, reed valve 84' can open, which helps guide fluid from advance fluid chamber 26 back to delay fluid chamber 28, while also allowing fluid from the outer surface 72 of control valve 58 through chamber vent 70 into valve chamber 68. In valve chamber 68, fluid can flow out of the open end of sleeve 60' and into housing 46.

[0033] It should be understood that the foregoing description describes one or more embodiments of the present invention. The invention is not limited to the specific embodiments disclosed herein, but is defined solely by the following claims. Furthermore, the statements contained in the foregoing description relate to specific embodiments and should not be construed as limiting the scope of the invention or the definitions of terms used in the claims, unless the terms or phrases are explicitly defined above. Various other embodiments, as well as various changes and modifications to the disclosed embodiments, will become apparent to those skilled in the art. All such other embodiments, changes, and modifications fall within the scope of the appended claims.

[0034] The terms “for example,” “like,” “as,” “such as,” and “etc.” as well as the verbs “comprise,” “have,” “include,” and other verb forms thereof, used in this specification and claims, are each interpreted as open-ended when used in conjunction with a list of one or more parts or other articles, meaning that the list is not considered to exclude other, additional parts or articles. Other terms should be interpreted using their broadest reasonable meaning unless they are used in a context that requires a different interpretation.

Claims

1. A variable camshaft timing control valve assembly comprising: a control valve having one or more valve faces and a valve cavity, wherein one or more cavity vents are configured to communicate fluid between an outer surface of the control valve and the valve cavity; a valve sleeve having a sleeve cavity to receive the control valve and a plurality of holes, at least one of the holes configured to be in fluid communication with an advance fluid chamber of a variable camshaft timing device and another one of the holes configured to be in fluid communication with a retard fluid chamber, wherein the control valve axially slides relative to the valve sleeve; and one or more reed valves on an outer surface of the valve sleeve configured to control fluid flow between one of the advance fluid chamber or the retard fluid chamber and the other one of the advance fluid chamber or the retard fluid chamber.

2. The variable camshaft timing control valve assembly of claim 1, wherein the reed valve is in fluid communication with the cavity vent.

3. The variable camshaft timing control valve assembly of claim 1, further comprising a pair of cavity vents.

4. The variable camshaft timing control valve assembly of claim 1, further comprising a center bolt housing configured to receive the control valve and the valve sleeve and attach the variable camshaft timing control valve assembly to a camshaft of a variable camshaft timing device or an internal combustion engine.

5. The variable camshaft timing control valve assembly of claim 1, wherein the valve sleeve further comprises a flat valve seat surface.

6. The variable camshaft timing control valve assembly of claim 1, further comprising a supply check valve at one end of the control sleeve, the supply check valve configured to regulate a fluid supply from a source to the valve sleeve.

7. The variable camshaft timing control valve assembly of claim 1, wherein the reed valve further comprises two connected flat sections, wherein a width of the flat sections is greater than a width of sections of the reed valve to which the flat sections are connected.

8. A variable camshaft timing control valve assembly comprising: a control valve having one or more valve faces and a valve cavity, wherein one or more cavity vents are configured to communicate fluid between an outer surface of the control valve and the valve cavity; a valve sleeve having a sleeve cavity to receive the control valve and a plurality of holes, at least one of the holes configured to be in fluid communication with an advance fluid chamber of a variable camshaft timing device and another one of the holes configured to be in fluid communication with a retard fluid chamber, wherein the control valve axially slides relative to the valve sleeve; and a first reed valve on an outer surface of the valve sleeve configured to control fluid flow between the advance fluid chamber and the retard fluid chamber and a second reed valve on the outer surface of the valve sleeve configured to control fluid flow between the retard fluid chamber and the advance fluid chamber.

9. The variable camshaft timing control valve assembly of claim 8, wherein the first reed valve is in fluid communication with a first cavity vent and the second reed valve is in fluid communication with a second cavity vent. ​ ​ 10. The variable cam timing control valve assembly of claim 8, further comprising a center bolt housing configured to receive the control valve and the valve sleeve and attach the variable cam timing control valve assembly to a variable cam timing device or a camshaft of an internal combustion engine.

11. The variable cam timing control valve assembly of claim 8, wherein the first reed valve or the second reed valve further comprises two connected flat sections, wherein a width of the flat sections is greater than a width of sections of the reed valve connecting the flat sections.

12. A variable cam timing control valve assembly comprising: a control valve having one or more valve faces and a valve cavity, wherein one or more cavity vent ports are configured to communicate fluid between an outer surface of the control valve and the valve cavity; a valve sleeve having a sleeve cavity to receive the control valve, an annular groove on an outer surface of the valve sleeve, a plurality of holes configured to communicate fluid between the sleeve cavity and the outer surface of the valve sleeve, and a flat valve seat surface on the outer surface of the valve sleeve; and a reed valve received by the annular groove, the reed valve comprising a flat section biased into engagement with the flat valve seat surface to releasably seal the holes and allow fluid to flow from one of an advance fluid chamber or a retard fluid chamber to the other of the advance fluid chamber or the retard fluid chamber.

13. The variable cam timing control valve assembly of claim 12, wherein the reed valve is in fluid communication with the cavity vent ports.

14. The variable cam timing control valve assembly of claim 12, further comprising a center bolt housing configured to receive the control valve and the valve sleeve and attach the variable cam timing control valve assembly to a variable cam timing device or a camshaft of an internal combustion engine.

15. The variable cam timing control valve assembly of claim 12, wherein the valve sleeve further comprises a flat valve seat surface. ​

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