GB2561003A

GB2561003A - Valve with noise reduction

Info

Publication number: GB2561003A
Application number: GB1705269.7A
Authority: GB
Inventors: Sauvage Frédéric; Bellamy Pascal; Cezon Nicolas; Kiris Spencer
Original assignee: Delphi International Operations Luxembourg SARL
Current assignee: Delphi International Operations Luxembourg SARL
Priority date: 2017-03-31
Filing date: 2017-03-31
Publication date: 2018-10-03
Anticipated expiration: 2037-03-31
Also published as: GB2561003A8; GB201705269D0; GB2561003B8; GB2561003B

Abstract

A valve comprising a valve seat, between an inlet and outlet, and a spherical valve seal 40, which is selectively seated and unseated from the valve seat. The sealing ball 40 is urged in to a sealing position by a valve member 34 which reciprocates along an axis 14. The valve stem 34 terminates in a tip face 38a which has a first recess 38b which takes the form of a concaved spherical frustum with a radius R38b greater than that of the ball R40. A second recess 38c extends into the valve member from, and form in a line of intersection with, the first recess. The ball engages the line of intersection when the valve member is in the open position. The arrangement allows lateral movement of the valve seal with respect to the valve seat during sealing whilst minimising oscillation, and hence noise, when the valve is open. A fixed valve seal is not required nor are additional noise cancelling elements. A common rail using such a valve is also disclosed.

Description

(54) Title of the Invention: Valve with noise reduction Abstract Title: Valve with noise reduction (57) A valve comprising a valve seat, between an inlet and outlet, and a spherical valve seal 40, which is selectively seated and unseated from the valve seat. The sealing ball 40 is urged in to a sealing position by a valve member 34 which reciprocates along an axis 14. The valve stem 34 terminates in a tip face 38a which has a first recess 38b which takes the form of a concaved spherical frustum with a radius R38b greater than that of the ball R40. A second recess 38c extends into the valve member from, and form in a line of intersection with, the first recess. The ball engages the line of intersection when the valve member is in the open position.

The arrangement allows lateral movement of the valve seal with respect to the valve seat during sealing whilst minimising oscillation, and hence noise, when the valve is open. A fixed valve seal is not required nor are additional noise cancelling elements.

A common rail using such a valve is also disclosed.

FIG. 3 /3

FIG. 1

2/3

FIG. 2

3/3

38d

34,38

38b

FIG. 4

38a

VALVE WITH NOISE REDUCTION

TECHNICAL FIELD OF INVENTION [0001] The present invention relates to a valve, more particularly to such a valve having a valve member which seats and unseats a ball with a valve seat to control flow from an inlet of the valve to an outlet of the valve, and even more particularly to an interface between the valve member and the ball which minimizes or reduces vibration and noise when the ball is not seated with the valve seat.

BACKGROUND OF INVENTION [0002] Valves of numerous configurations are known for controlling fluid flow from an inlet of the valve to an outlet of the valve. In one known valve, a valve member acts on a ball such that the valve member is reciprocated between a closed position and an open position. In the closed position, the valve member urges the ball into contact with a valve seat, thereby preventing fluid communication from the inlet to the outlet. Conversely, in the open position, the valve member allows the ball to be unseated with the valve seat, thereby permitting fluid communication from the inlet to the outlet. An example of one such valve is illustrated in United States Patent Application Publication No. US 2016/0273503 Al to Marechal et al., the disclosure of which is incorporated herein by reference in its entirety. In order to allow for variations in concentricity between the valve member and the valve seat, the ball is not fixed to the valve member, thereby allowing relative movement between the valve member and the ball. A known interface between the valve member and the ball is to provide a recess in a tip of the valve member into which a portion of the ball is received.

The recess takes the form of a concave spherical cap having a radius that is larger than the ball. Consequently, when the valve member urges the ball into contact with the valve seat, the ball is able to move laterally within the recess in order to self-center with the valve seat, thereby accommodating variations in concentricity between the valve member and the valve seat. Since the radius of the recess is greater than the radius of the ball, the ball contacts the recess in a point contact. However, the ability for the ball to move laterally in order to self-center with the valve seat raises issues when the valve member is in the open position and the ball is unseated with the valve seat. More specifically, fluid flow from the inlet to the outlet when the valve member is in the open position causes a perturbation at the back of the ball which leads to lateral oscillation of the ball within the recess. The oscillation of the ball may be amplified or resonated by conduits of the system to which the valve is applied, thereby becoming an audible noise which may be objectionable to people in close proximity to the valve. In order to alleviate this noise issue, it has been known to add noise cancelling elements to the system; however, this adds cost and complexity to the system. It has also been known to fix the ball on the valve member; however, such an arrangement forgoes the benefit of self-centering of the ball on the valve seat to accommodate concentricity variations between the valve member and the valve seat.

[0003] What is needed is a valve which minimizes or eliminates one or more of the shortcomings as set forth above.

SUMMARY OF THE INVENTION [0004] Briefly described, a valve includes an inlet; an outlet; a valve seat disposed between the inlet and the outlet; a ball having a first radius, the ball being selectively seated and unseated with the valve seat such that fluid communication is provided from the inlet to the outlet when the ball is unseated with the valve seat and such that fluid communication is prevented from the inlet to the outlet when the ball is seated with the valve seat; and a valve member which reciprocates along an axis between a closed position in which the valve member urges the ball to be seated with the valve seat and an open position which allows the ball to be unseated with the valve seat. The valve member terminates in a valve member tip face such that the valve member tip face includes a first valve member tip recess defining a concave spherical frustum surface having a second radius which is greater than the first radius such that a portion of the ball is received within the first valve member tip recess. The valve member tip face also includes a second valve member tip recess which extends into the valve member from the first valve member tip recess, thereby forming a line of intersection where the second valve member tip recess intersects the first valve member tip recess, whereby the ball engages the line of intersection when the valve member is in the open position, thereby minimizing lateral movement of the ball. Since the line of intersection minimizes lateral movement of the ball when the valve member is in the open position, noise is also minimized.

[0005] A common rail includes a wall which defines a volume therewithin and also includes a valve having an inlet constant fluid communication with the volume; an outlet; a valve seat disposed between the inlet and the outlet; a ball having a first radius, the ball being selectively seated and unseated with the valve seat such that fluid communication is provided from the inlet to the outlet when the ball is unseated with the valve seat and such that fluid communication is prevented from the inlet to the outlet when the ball is seated with the valve seat; and a valve member which reciprocates along an axis between a closed position in which the valve member urges the ball to be seated with the valve seat and an open position which allows the ball to be unseated with the valve seat. The valve member terminates in a valve member tip face such that the valve member tip face includes a first valve member tip recess defining a concave spherical frustum surface having a second radius which is greater than the first radius such that a portion of the ball is received within the first valve member tip recess. The valve member tip face also includes a second valve member tip recess which extends into the valve member from the first valve member tip recess thereby, forming a line of intersection where the second valve member tip recess intersects the first valve member tip recess, whereby the ball engages the line of intersection when the valve member is in the open position, thereby minimizing lateral movement of the ball.

BRIEF DESCRIPTION OF DRAWINGS [0006] This invention will be further described with reference to the accompanying drawings in which:

[0007] Fig. 1 is an axial cross-sectional view of a valve in accordance with the present invention showing a valve member in a closed position;

[0008] Fig. 2 is the axial cross-sectional view of Fig. 1, now showing the valve member in an open position;

[0009] Fig. 3 is an enlarged view of a portion of Fig. 1 showing a valve member tip of the valve member and a ball which is acted on by the valve member; and [0010] Fig. 4 is a view of the valve member tip of Fig. 3 looking in the direction of an axis of the valve member.

DETAIFED DESCRIPTION OF INVENTION [0011] According to FIGS. 1 and 2, there is shown a pressure regulating valve 10, hereinafter referred to as valve 10, arranged at the end of a common rail 12 of a system for injecting fuel under pressure. Valve 10 described herein and its specific use have been chosen by way of non-limiting example only, the invention being able to benefit other valves operating in different environments.

[0012] Common rail 12 is commonly elongated and tubular in shape, extending along an axis 14. Common rail 12 has a wall 16 defining a central cylindrical volume 18 intended to contain fuel under high pressure and to supply several fuel injectors (not shown) for supplying metered amounts of fuel to a fuel consuming device (not shown), which may be, by way of non-limiting example only, an internal combustion engine. Volume 18 opens at the end of common rail 12 into a common rail counterbore 20 of common rail 12 in which valve 10 is fixed. As shown in the figures, common rail counterbore 20 is stepped.

[0013] Valve 10 comprises a valve body 22, a portion of which is directly arranged in common rail counterbore 20. Valve body 22 extends axially between a seat face 24 and a head face 26 and is provided with an axial bore 28 which is centered about and extends along axis 14. While common rail 12 has also been described herein as extending along axis 14, it should be understood that common rail 12 may alternatively extend along a different axis. Axial bore 28 opens to seat face 24 at a seat counterbore 30 and opens to head face 26 at a head counterbore 32. As shown in FIGS. 1 and 2, seat counterbore 30 may be a stepped counterbore. Within axial bore 28 there is slidably arranged a valve member 34, commonly referred to as the needle with reference to its elongated shape extending between a flat head 36 opposite a valve member tip 38 such that valve member tip 38 emerges in seat counterbore 30. Valve member 34 is centered about and extends along axis 14 and interfaces with axial bore 28 is a close sliding fit which prevents fuel from passing between the interface of axial bore 28 and valve member 34. Valve member tip 38 cooperates with a ball 40 which is also within seat counterbore 30, in order to seat and unseat ball 40 with a valve seat 42 to thereby open or close a discharge orifice 44 (an inlet to valve 10 and valve body 22) which extends from valve seat 42 to volume 18. Ball 40 is a sphere having a ball radius R40. Valve seat 42 is nominally centered about axis 14; however, manufacturing tolerances may lead to variations in concentricity between valve seat 42 and valve member 34. It should be noted that ball 40 is not fixed to valve member 34, and consequently, relative movement is permitted between ball 40 and valve member 34. In this way, valve member 34 is able to self-center about valve seat 42 when ball 40 is seated with valve seat 42 to ensure that a positive fluid seal is made, thereby obviating any concentricity variations that may exist between valve seat 42 and valve member 34, for example due to manufacturing tolerances. The interface of valve member tip 38 and ball 40 will be described in greater detail later. A discharge channel 46 (an outlet to valve 10 and valve body 22) extends through valve body 22, generally perpendicular to axis 14, such that discharge channel 46 provides for fluid communication from seat counterbore 30 to common rail counterbore 20 and also to an outlet port 48 of common rail 12 which extends outward from common rail counterbore 20 to a low pressure reservoir (not shown). As shown in the figures, valve seat 42 is between discharge orifice 44 and discharge channel 46.

[0014] On the side of head 36 of valve member 34, a magnetic core 50 is axially movable along axis 14 within a space defined by a cap 52 secured to the valve body 22 by means of a tight fitting tubular portion 54 of cap 52 around valve body

22.

[0015] Head 36 of valve member 34 emerges in head counterbore 32 in which a spring 56 is arranged around head 36 such that spring 56 is axially compressed between the base of the head counterbore 32 and magnetic core 50 so as to permanently bias magnetic core 50 away from head face 26 of valve body 22. [0016] Valve 10 also comprises an electromagnetic actuator 60 comprising an overmolded coil-connector assembly 62 inserted in an actuator body 64. In the example illustrated in the figures, actuator body 64 has the shape of a cylindrical cup made by stamping a magnetic metal sheet of substantially constant thickness. Actuator body 64 is provided with a cylindrical peripheral wall 66 extending axially along axis 14 from a transverse bottom wall 68 made in the thickness of peripheral wall 66 to an upper edge 70. Coil-connector assembly 62 is an integrally molded plastic assembly comprising a cylindrical coil portion 76 inserted into the actuator body 64 and a connector portion 78 extending laterally from the coil portion 76. Coil portion 76 comprises an annular electric coil 80. [0017] Connector portion 78 of coil-connector assembly 62 comprises a peripheral wall forming a connector body 86 in the center of which are arranged electrical terminals 88, which are in electrical communication with the ends of electric coil 80. Connector body 86 is designed to mate with a complementary connector (not shown) so as to be able to supply electricity to electric coil 80 so that a magnetic field may be generated which draws magnetic core 50 toward valve body 22, thereby urging valve member 34 into a closed position as shown in FIG. 1 which urges ball 40 to be seated with valve seat 42 such that fluid communication is prevented from discharge orifice 44 to discharge channel 46. Conversely, when electricity to electric coil 80 is terminated, the magnetic field ceases, thereby allowing spring 56 to urge magnetic core 50 away from valve body 22. With magnetic core 50 moved away from valve body 22, valve member 34 is free to move to an open position which allows ball 40 to unseat with valve seat 42 as a result of fluid pressure acting on ball 40 from discharge orifice 44, thereby providing fluid communication from discharge orifice 44 to discharge channel 46 as shown in FIG. 2. In this way, electric coil 80 is used to reciprocate valve member 34 between the closed position and the open position. In use, when the pressure within volume 18 of common rail 12 reaches a threshold, electricity to electric coil 80 is terminated in order to unseat ball 40 with valve seat 42, thereby reducing the pressure within volume 18. Conversely, when the pressure within volume 18 has dropped to a predetermined level, electricity is applied to electric coil 80 in order to seat ball 40 with valve seat 42, thereby preventing further drop in pressure within volume 18 through discharge orifice 44. Application of electricity to electric coil 80 may be controlled by an electronic control unit (not shown) which monitors operating conditions of the internal combustion engine based on one or more sensor inputs and determines when to open and close valve 10.

[0018] The interface of valve member tip 38 and ball 40 will now be described in greater detail with additional reference to FIGS. 3 and 4. Valve member tip 38 terminates valve member 34 in a valve member tip face 38a which traverses axis and which faces toward ball 40. Valve member tip face 38a includes a first valve member tip recess 38b which takes the form of a spherical frustum surface which is concave. In other words, first valve member tip recess 38b is the surface of a sphere which has been truncated in two places, and is preferably truncated by parallel planes which are perpendicular to axis 14, and even more preferably is truncated by parallel planes which fall within a common hemisphere. First valve member tip recess 38b has first valve member tip recess radius R.38b which is greater than ball radius R40 and which is centered on axis 14, and consequently, a portion of ball 40 is received within first valve member tip recess 38b. Valve member tip face 38a also includes a second valve member tip recess 38c which extends into valve member tip 38 from first valve member tip recess 38b, thereby forming a line of intersection 38d where second valve member tip recess 38c intersects first valve member tip recess 38b. Fine of intersection 38d is closed,

i.e. is a closed figure such that line of intersection 38d can be traced with the same starting and stopping points, without crossing or retracing any part of line of intersection 38d. Preferably, line of intersection 38d is a circle which is formed by second valve member tip recess 38c taking the form of a concave spherical cap having a spherical cap radius R38C which is less than ball radius R40 and which is centered on axis 14. Alternatively, second valve member tip recess 38c may take the form of a cylinder, cone, frustum (either conical or spherical), or combinations thereof having a surface of revolution centered about axis 14, thereby maintaining line of intersection 38d as a circle. In further variations, second valve member tip recess 38c may take the form of a polygonal prism, polygonal pyramid, or any other shape which would form a closed figure. It should be noted that that the depth of second valve member tip recess 38c in FIG. 3 has been exaggerated for clarity by making spherical cap radius R38C smaller than may be used in practical implementation. Consequently, in practice, spherical cap radius R38C may be made greater than illustrated in FIG. 3 while still being less than ball radius R40 in order to maintain line of intersection 38d. It should also be noted that second valve member tip recess 38c can be easily produced by a simple turning tool or milling tool having a radius that is less than ball radius R40.

[0019] As a result of valve member tip 38 having first valve member tip recess 38b and second valve member tip recess 38c, ball 40 is able to self-center on valve seat 42 when ball 40 is urged into contact with valve seat 42 by application of electric current to electric coil 80. In this way, variations in concentricity between valve member 34 and valve seat 42 are accommodated by first valve member tip recess 38b. Conversely, when no electric current is applied to electric coil 80 in order to reduce the pressure within volume 18, fluid pressure urges ball 40 to unseat from valve seat 42, thereby allowing pressure to decrease due to fuel flow through discharge orifice 44, past valve seat 42 to discharge channel 46, and finally to outlet port 48. However, line of intersection 38d captures ball 40, thereby minimizing or preventing lateral movement and oscillation of ball 40 relative to valve member 34, and consequently, minimizing or eliminating noise that would otherwise result from lateral movement and oscillation of ball 40. [0020] While this invention has been described in terms of preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.

Claims

CLAIMS:

1. A valve comprising: an inlet;

an outlet;

a valve seat disposed between said inlet and said outlet; a ball having a first radius, said ball being selectively seated and unseated with said valve seat such that fluid communication is provided from said inlet to said outlet when said ball is unseated with said valve seat and such that fluid communication is prevented from said inlet to said outlet when said ball is seated with said valve seat; and a valve member which reciprocates along an axis between a closed position in which said valve member urges said ball to be seated with said valve seat and an open position which allows said ball to be unseated with said valve seat, said valve member terminating in a valve member tip face such that said valve member tip face includes a first valve member tip recess defining a concave spherical frustum surface having a second radius which is greater than said first radius such that a portion of said ball is received within said first valve member tip recess, and said valve member tip face also includes a second valve member tip recess which extends into said valve member from said first valve member tip recess, thereby forming a line of intersection where said second valve member tip recess intersects said first valve member tip recess whereby said ball engages said line of intersection when said valve member is in said open position, thereby minimizing lateral movement of said ball.

2. A valve as in claim 1, wherein said line of intersection is a closed figure.

3. A valve as in claim 1, wherein said second valve member tip recess defines a spherical cap surface which is concave.

4. A valve as in claim 3, wherein said spherical cap surface has a third radius which is less than said first radius.

5. A valve as in claim 4, wherein said second radius and said third radius are centered on said axis.

6. r A valve as in claim 3 wherein said line of intersection is a circle. 3

7. A valve as in claim 1 wherein said line of intersection is a circle.

8. A common rail comprising: a wall which defines a volume therewithin; and 10 a valve in accordance with claim 1 such that said inlet is in constant fluid

communication with said volume

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