US3330300A

US3330300A - Fluid flow control valves

Info

Publication number: US3330300A
Authority: US
Inventors: Harold E Jackson
Original assignee: Petrol Injection Ltd
Current assignee: Petrol Injection Ltd
Priority date: 1964-02-25
Filing date: 1965-02-23
Publication date: 1967-07-11
Anticipated expiration: 1984-07-11
Also published as: GB1098822A

Description

July 11, 1967 H. E. JACKSON 3,330,3

FLUID FLOW CONTROL VALVES Filed Feb. 25, 1965 2 Sheets-Sheet 1 y 9 H. E. JACKGON 3,3303% FLUID FLOW CONTROL VALVES Filed Feb. 23, 1965 2 Sheds-Sheet 2 United States Patent 0 3,330,300 FLUID FLGW CONTROL VALVES Harold E. Jackson, Plympton St. Mary, Devon, England,

assignor to Petrol Injection Limited, Plymouth, England, a British company Filed Feb. 23, 1965, Ser. No. 434,596 Claims priority, application Great Britain, Feb. 25, 1964, 7,894/ 64 10 Claims. (Cl. 137614.14)

This invention relates to fluid flow control valves.

It is an object of the present invention to provide a fluid flow control valve which has a valve member movable between first and second seated positions and biased toward the first seated position, and control pressure responsive means operably connected to the valve member to unseat it from the first seated position at a first value of the control pressure and to seat the valve member in the second seated position at a second value of the control pressure, the valve member occupying an open position intermediate the first and second seated positions at control pressures between the first and second values, and including a second pressure responsive means responsive to the pressure of the fluid the flow of which is being controlled, or to the pressure of another fluid, and which is movable between operable and nonoperable positions, in the operable position permitting movement of the valve member in a direction from the second to the first seated position but not in the reverse direction, and in the inoperative position permitting movement of the valve member in either direction between the first and second seated positions.

Such a control valve as described in the preceding paragraph may be utilised to control fuel flow under engine starting and overrun conditions in an engine in which fuel is supplied by an engine driven pump. In such an application, the first pressure responsive means would be exposed to the engine inlet manifold vacuum and the second pressure responsive means would be responsive to fluid pressure changes dependent on engine operating speed, e.g. to the pressure on the output side of the pump or to the pressure of the engine lubricating pump. With the engine stationary, the valve member would be seated in the first seated position. Operation of the engine starter, with the engine throttle closed, causes a vacuum in the inlet manifold which actuates the first pressure responsive means to unseat the valve member from the first seated position, allowing fuel flow to the engine. When the engine reaches idling speed, the fuel pressure, or the lubricating pump pressure, is suflicient to operate the second pressure responsive means to cause the latter to prevent the valve member returning to the first seated position, even though the engine throttle be opened and the inlet manifold vacuum decreased. During engine overrun conditions, i.e. conditions of high engine speed and closed throt tle, the engine does not require fuel and it is arranged that under such conditions the inlet manifold vacuum is suflicient to move the valve member from the intermediate position to the second seated position, thereby cutting-off fuel supply to the engine. Subsequent opening of the throttle permits the valve member to move back to an intermediate position until the engine stops when the valve member returns to the first seated position. Thus, such a control valve meets the requirements of adequate fuel supply to the engine under starting conditions and cuttingoff of fuel supply under conditions of engine overrun during which fuel supply is unnecessary.

The control valve can also be used for other applications in which it is desired to have fluid flow between two valves of a control pressure source, controlling the first mentioned pressure responsive device, and to cut-ofl? fluid flow for other valves of the control source. The control Patented July 11, 1967 source can be a source of negative (vacuum) or positive pressure. The second pressure responsive device can be responsive to the pressure of the fluid, the flow of which is being controlled, or to a different control pressure.

The valve member may be a plate valve movable between first and second annular seats in a chamber that between the seats has a larger internal cross-section than the valve member dimension. The valve member can be biased towards the first seated position by a first resilient device and its intermediate position between the annular seats determined by a stop member displaceable against a second resilient device, less resilient than the first. Thus, when the valve member is unseated by the first pressure responsive means it abuts the stop member, unless the control pressure source is sufficient to overcome the second resilient device and move the valve member to the second seated position.

The first pressure responsive means can be a resilient diaphragm to which the valve member is connected. The second pressure responsive means may comprise a piston mounted in a cylindrical chamber, and subject to differential control pressure, e.g. in the particular application mentioned above, the inlet and outlet pressures of the fuel pump, or of the lubricating pump, are applied to respective sides of the piston. Alternatively, only one side of the piston is exposed to a control pressure. The piston is so coupled to the first pressure responsive means that the latter can effect movement of the valve member in the di rection from the first to the second seated position whether or not the piston is actuated. However, a sufiicient fuel pressure or engine lubricant pressure, subsequent to unseating of the valve member by the first pressure responsive means, moves the piston sufliciently for the latter to cooperate with the first pressure responsive means to prevent return of the valve member towards the first seated position whilst permitting the valve member to be moved on towards the second seated position.

By way of example, an embodiment of the invention will be described in greater detail with reference to the accompanying drawings in which:

FIG. 1 is a diagrammatic sectional elevation of a control valve according to the invention showing the valve member in one of its two seated positions,

FIG. 2 is a view similar to FIG. 1 showing the valve member intermediate its two seated positions, and

FIG. 3 illustrates a fuel injection system incorporating a control valve as shown in FIGS. 1 and 2.

The control valve has a chamber 1 having an enlarged diameter portion 2 shaped to define lower and upper

annular seats

3 and 4 for a plate valve 5 having a diameter smaller than that of the portion 2. The plate valve 5 is biased towards a position in which it seats on the lower seating 3 (FIG. 1) by a coil spring 6 that supports a cup 7 enclosing a further spring 8, stronger than spring 6, bearing against the top of the chamber 1. A shoulder 9 limits the downwards movement of the cup 7 from which depends a rod 10 serving as a stop member to prevent movement of the plate valve 5 to seat on the upper seat 4 until the valve 5 is acted on by a force sufficient to overcome the spring 8. A fluid inlet conduit 11 leads to the chamber 1 on the underside of the seating 3 and a fluid outlet conduit 12 leads from the chamber 1 above the seating 4. The inlet conduit 11 also is connected to the portion of the chamber 1 above the piston 7 for pressure balanced operation. The valve 5 thus prevents fluid flow between the inlet 11 and the outlet 12 when it is seated on the lower seating 3 or the upper seating 4 but permits such fluid flow when it occupies an intermediate unseated position (FIG. 2).

From the lower end of the chamber 1, a conduit 13 leads to a chamber 14 across which extends a resilient diaphragm 15, the upper side of which is secured to the 3 plate valve 5 by a rod 16 so that flexure of the diaphragm can move the plate valve between the

seats

3 and 4; From the lower side of the diaphragm depends a spigot 17 having a conical lower end portion extending into a tube 18' dependent from a wall'19 which defines the lower part of the chamber 14 and forms part of a housing 20 having a cylindrical portion accommodating a piston 21. The piston 21 has a cylindrical recess 22 in its upper face. The'mouth of the recess is flared and the tube 18 partly extends into the recess when the piston is in its lowermost position in the cylinder, defined by an annular stop 23, towards which position it is biasedby a spring 24 7 (FIG. 1). The wall of the tube 18 has apertures spaced around its peripheral surface, each aperture accommodating a 'ball 25. When the balls 25 are aligned with the flared mouth of the recess, they can be displaced radially outwards by downwards movement of the spigot 17 but when the balls 25 are aligned with the unflared region of the tion thereof and the wall 19, and a port 28 in the housing 20 communicates with the underside of the piston 21.

Thus, if a source of vacuum is connected to the, conduit 26,. in the presence of a vacuum sufficient to'overcome the spring 8 the diaphragm 15 will unseat the valve 5 from the lower seating 3 and cause it to abut the stop member 1 0 (FIG. 2). Further increase in the vacuum (i.e. decrease in pressure) eventually causes the diaphragm to exert suflicient force to overcome the spring 8 when the valve 5 will become seated on the upper seating 4. Thus between the two vacuum conditions mentioned, fluid flow between conduits 11 and 12 can occur. In the absence of any positive pressure difference between the

ports

28 and 27, the diaphragm 15 will control fluid flow past the valve 5, permitting such flow only between the two vacuum conditions referred to above.

The control valve as a whole can be used in a fuel injection system for an internal combustion engine in which the fuel is supplied to the injectors by an engine driven impeller, so that the fuel supply pressure varies with engine speed. The control valve is used to control the fuel supply from the impeller to provide an adequate supply of fuel under starting conditions and during normal running of the engine and to cut-off the fuel supply when the engine is stationary or operating under overrun conditions, i.e. at a fast engine speed with the throttle closed, e.g. when a vehicle powered by. the engine is running downhill.

'A fuel injection system embodying a control valve according to the present invention, and as described above, is illustrated diagrammatically in FIG. 3. A more detailed disclosure of such a system is contained in the specification of my application Serial No. 482,994 filed Aug. 10,

1965 for Fuel Injection Systems now Patent No.

. relief valve 34. The output pressure of the impeller increases with increasing engine speed and is supplied to a control valve 35 constructed as shown in FIGS. 1 and 2.

The impeller output is connected to the inlet 11 and port 28 of the control valve 35, the outlet 12 of which is connected via a flow restrictor 36 and a gas/air separation chamber 37 to a fuel manifold 38. The manifold 38 is The pressure of fuel supplied to the injectordevices 41 is controlled in dependence on engine speed by the impeller 33 and is metered in dependence with engine inlet manifold vacuum by a metering valve 43. The metering valve 43 has a cam controlled valve member 44, the valve being connected to the inlet manifold 42, by 'a line 45, downstream of a throttle valve 46, for operation of the valve 44 in response to inlet manifold vacuum changes.

Fuel surplus to the engine operating requirements is returned from the metering valve 43 via a pressure balance valve 47 to a collection tank 48 from where it is pumped to the tank'32 by an engine driven scavenge pump 49. V r

The line 45 is connected also to the port 26 of the control valve 35, to apply inletmanifold vacuum thereto.

The system also includesan air pump 50 for supplying atomising air at a suitable low pressure to the injector devices 41 as well as to the relief valve 34 and the pressure balance valve 47, so that fuel flow throughout the system is opposed by the atomising air pressure.

Connected between the'gas/ air separator 37 and lection tank 48 is a bleed valve 51 controlled by a bellows 52 responsive to atmospheric pressure. a

A detailed description of the system will not be given since it is not relevant to the present invention. Such a description is to be found in the specification of the aforementioned application Serial No. 482,994 filed Aug. 10,

1965 for Fuel Injection Systems.

The operation of the control device in the system shown in FIG. 3 is as follows. When the engine is stationary, the piston 21 is seated on the stop 23 by the spring24 and the balls 25 are aligned with the flared mouth of the recess 22, permitting the spring 6 to seat the valve 5 on the lower seating 3, the spigot having been moved past the balls since they are free to slide radially" outwardly and since there is no pressure diflerence across the diaphragm 15 (FIG. 1). V

Upon turning of the engine by the starter motor with the throttle 46 closed, or slightly open, a partial vacuum.

exists in the inlet manifold 42 and acts on the upper side of the diaphragm 15 causing thelatter to flex lifting the rod 16 and pushing the valve 5 off the seat 3 until it abuts the stop rod 10 (FIG. 2). Turning of the engine also operates the impeller 33 which thus supplies fuel through the inlet conduit 11 past the valve 5 and through the outlet conduit 12 to the fuel supply line for the injectors 41. I

As the engine reaches idling'speed, with the throttle 46 still closed, the pressure generated across the impeller 33 and applied between the ports 27 and '28is arranged to be sufiicient to cause the piston 21 to rise in the cylinder 20 so that the wall of the recess 22 closes inon the balls 25, preventing them from moving outwardly. The conical end of the spigot 17 is held'betwen the balls 25 preventing downwards movement of the spigot 17 and the rod 16 (FIG. 2) and thus ensuring that the valve 5 cannot be returned to the seat 3, whilst the engine is running, even though the engine throttle 46 is opened to increase the engine speed and the manifold vacuum destroyed, so that in the inlet manifold 42, sub'stantially higher than under idling conditions, and this high vacuum acting on the diaphragm 15 is arranged to be sufficient to cause the diaphragm to exert, via

rods

16 and 10 and the spring cup '7, sufiicient force to overcome the spring 8. The valve 5 a then is moved upwards and seats on the upper seating 4, thereby preventing fuel flow from the inlet 11 to the outlet 12. It will be appreciated that due to the conical end the colof the spigot 17, the balls 25 do not prevent upwards flexing of the diaphragm under these conditions.

Upon again opening the throttle 46, the vacuum in the inlet manifold 42 decreases, or is destroyed, the diaphragm 15 flexes downwards and this movement, together with the force exerted by the spring 8, returns the valve 5 to the intermediate position previously referred to so that fuel supply to the engine is recommenced, the downwards travel of the plate valve 5 being determined when the spigot 17 is arrested by the balls 25.

Upon stopping of the engine, there is no pressure difference across the impeller 33, and hence across the

ports

27, 28, and the piston 21 descends to seat against the stop member 23. The vacuum in the engine inlet manifold 42 is destroyed and the spring 6 and diaphragm 15 exert a downwards force on the spigot 17 which descends into the recess 22 since the balls 25 are again free to move radially outwards.

In an alternative arrangement, the piston 21 may be exposed to the engine lubricating pump pressure, the piston being moved from the position shown in FIG. 1 to the position shown in FIG. 2 when the engine reaches idling speed, the lubricating pump pressure maintaining the piston in the position shown in FIG. 2 during normal running of the engine. Upon stopping the engine, the lubricating pump pressure reduces to zero and the piston is moved back by the spring 24 to the position shown in FIG.1.

The control valve described above provides a relatively simple means of providing adequate fuel for the engine under starting conditions and of economising fuel under engine overrun conditions.

It will be appreciated that the control valve can be used in other applications both in its basic form in which the plate valve 5 is controlled only by the diaphragm 15, the piston 21 and its associated components being omitted, as Well as in the form illustrated. The control valve can be utilised as illustrated for control of fluid flow in response to vacuum, as negative pressure, applied to the diaphragm 15. For control by positive pressure, the valve can readily be modified as, for example, by inversion of the plate valve assembly so that the plate valve 5 normally is seated in the upper position and moved towards the lower position with increasing control pressure. The piston 21 can be controlled by differential pressure by appropriate connection of the

ports

27 and 28 or by connection of a control source only to one of those ports, the other not being utilised. The control valve can be used both for controlling liquid and gaseous fluid flows.

We claim:

1. A fluid flow control valve including a housing having first and second valve seats defined therein, a valve member mounted in the housing for movement between a first closed position in which it engages said first valve seat and a second closed position in which it engages said second valve seat, said control valve being open to permit fluid flow when said valve member occupies a position intermediate said first and second closed positions, resilient means biasing the valve member towards said first closed position, a fluid pressure-responsive device exposed to a source of control pressure for movement in response to changes in said control pressure, and means operably coupling said valve member to the said control pressureresponsive device for movement thereof in response to movement of the control pressure-responsive device so that the said valve member is moved from said first closed position at a first value of the said control pressure and is moved to the said second closed position at a second value of the said control pressure, the said valve member occupying a position intermediate said first and second closed positions at values of said control pressure intermediate said first and second values, a movement control device movable between operative and inoperative positions, a movement limiting member, means coupling said limiting member to the said valve member for movement therewith; and locking means engageable with said limiting member to limit movement of said valve member in a direction towards said first closed position, said locking means being adapted to permit movement of said valve member in a direction towards said second closed position, said locking means further being displaceable by said limiting member when the said movement control device occupies said inoperative position, to permit movement of said valve member in a direction towards said first closed position, said locking means being engaged by said movement control device in the said operative position thereof to prevent displacement of the said locking means, whereby the latter engages the said limiting member to limit movement of said valve member in a direction towards said first closed position.

2. A fluid flow control valve according to claim 1, in which the said valve member is a plate valve member, and said first and second valve seats are annular valve seats.

3. A fluid flow control valve according to claim 1, including a stop device against which the said valve member abuts at values of said control pressure intermediate the said first and second values, and means mounting the stop device for movement away from the first valve seat in response to values of said control pressure equal to or exceeding the said second value, to permit the valve member to occupy the said second closed position.

4. A fluid flow control valve according to claim 3, in which the said means mounting the stop device comprises a piston, and a resilient device biasing the piston towards the first closed position.

5. A fluid flow control valve according to claim 1, in which the said fluid pressure-responsive device comprises a resilient diaphragm.

6. A fluid flow control valve according to claim 1, including a fixed tubular member cooperating with the said movement control device and having a bore into which said movement limiting member extends, means mounting the said movement limiting member for movement into and out of the fixed tubular member with movement of the valve member towards the first and the second closed positions respectively, the said tubular member having apertures in the wall thereof and a ball slidably mounted in each aperture, the balls being engageable by the said movement control device in the said operative position thereof and thereby engaging the said movement limiting member to limit movement of the latter into the fixed tubular member, the balls being displaceable by the limiting member, when the movement control device occupies the said inoperative position, to permit movement of the movement limiting member into the bore of the fixed tubular member.

7. A fluid flow control valve according to claim 6, in which the said movement limiting member includes a portion which tapers in a direction into the fixed tubular member, the said balls being engageable with the tapered portion when the movement control device occupies the said operative position to limit movement of the movement limiting member into the tubular member while permitting movement of the valve member in an opposite direction.

8. A fluid flow control valve according to claim 1, in which the movement control device comprises pressureresponsive means exposed to a source of further control pressure.

9. A fluid flow control valve according to claim 1, in which the said movement limiting member is mounted on the said pressure-responsive device.

10. A fluid flow control valve including a housing having first and second valve seats defined therein, a valve member mounted in the housing for movement between a first closed position in which it engages said first valve seat and a second closed position in which it engages said second valve seat, said control valve being open to permit fluid flow when said valve member occupies a position intermediate said first and second closed positions,

v 2" resilient means biasing the valve member towards said first closed position, a fluid pressure responsive device exposed to a source of control pressure for movement in response to changes in said control pressure, and means operably coupling said valve member to the said control pressure responsive device for movement thereof in response to movement of the control pressureresponsive device so that the said valve member is moved from said 1 first closed position at a first value of the said control Yin and telescopiually cooperating with the tubular recess,

the said tubular member having apertures defined in the,

Wall thereof and a ball slidably disposed in each aperture, a movement limiting member extending into the fixed tubular member and means coupling the said limiting memher to the valve member for movement thereof into and out of the fixed tubular member in response to movement of the valve member into the said first and second closed positions respectively, the said limiting member having a portion which tapers in a direction into the tu- Q a (j V bular member, the said piston member being movable between an operative and an inoperative position, in the said operative position the said apertures being aligned with the wall of the said cylindrical recess, whereby the latter limits sliding movement of the said balls, the balls thereby being engageable with the tapered portion of the said limiting member to limit movement of the limiting mem-- her into the said tubular member but permit movement thereof out of the tubular member, in the said inoperative position the said apertures being aligned with the fiared' mouth of the cylindrical recess and the said balls being displaceable by the said limiting member to permit movement of the limiting member into and out of the tubular member.

References Cited UNITED STATES PATENTS 2,338,707 1/1944 Boynton 25189 2,843,098 7/ 1958 DolZa 123--119 2,868,182 1/1959 Cornelius 12397 2,877,998 3/1959 1 Cornelius 12397 2,957,464 10/1960 Dolza' 123-119 2,977,944 4/ 1961 Holley 12387 2,993,485 7/1961 Cornelius 12397 MARK NEWMAN, Primary Examiner.

LAURENCE M. GOODRIDGE, Examiner.

Claims

1. A FLUID FLOW CONTROL VALVE INCLUDING A HOUSING HAVING FIRST AND SECOND VALVE SEATS DEFINED THEREIN, A VALVE MEMBER MOUNTED IN THE HOUSING FOR MOVEMENT BETWEEN A FIRST CLOSED POSITION IN WHICH IT ENGAGES SAID FIRST VALVE SEAT AND SECOND CLOSED POSITION IN WHICH IT ENGAGES SAID SECOND VALVE SEAT, SAID CONTROL VALVE BEING OPEN TO PERMIT FLUID FLOW WHEN SAID VALVE MEMBER OCCUPIES A POSITION INTERMEDIATE SAID FIRST AND SECOND CLOSED POSITIONS, RESILIENT MEANS BIASING THE VALVE MEMBER TOWARDS SAID FIRST CLOSED POSITION, A FLUID PRESSURE-RESPONSIVE DEVICE EXPOSED TO A SOURCE OF CONTROL PRESSURE FOR MOVEMENT IN RESPONSE TO CHANGES IN SAID CONTROL PRESSURE, AND MEANS OPERABLY COUPLING SAID VALVE MEMBER TO THE SAID CONTROL PRESSURERESPONSIVE DEVICE FOR MOVEMENT THEREOF IN RESPONSE TO MOVEMENT OF THE CONTROL PRESSURE-RESPONSIVE DEVICE SO THAT THE SAID VALVE MEMBER IS MOVED FROM SAID FIRST CLOSED POSITION AT A FRIST VALUE OF THE SAID CONTROL PRESSURE AND IS MOVED TO THE SAID SECOND CLOSED POSITION AT A SECOND VALUE OF THE SAID CONTROL PRESSURE, THE SAID VALVE MEMBER OCCUPYING A POSITION INTERMEDIATE SAID FIRST AND SECOND CLOSED POSITIONS AT VALUES OF SAID CONTROL PRESSURE INTERMEDIATE SAID FIRST AND SECOND VALUES, A MOVEMENT CONTROL DEVICE MOVABLE BETWEEN OPERATIVE AND INOPERATIVE POSI-