GB2550883A

GB2550883A - Bidirectional HP valve

Info

Publication number: GB2550883A
Application number: GB1609350.2A
Authority: GB
Inventors: Vioulac Maxime; Robart Didier
Original assignee: Delphi International Operations Luxembourg SARL
Current assignee: Delphi International Operations Luxembourg SARL
Priority date: 2016-05-26
Filing date: 2016-05-26
Publication date: 2017-12-06
Anticipated expiration: 2036-05-26
Also published as: GB201609350D0; GB2550883B

Abstract

A high pressure hydraulic commutator 10 adapted to be arranged in a high pressure fluid equipment between a first high pressure circuit wherein fluid is at a first pressure and a second high pressure circuit wherein fluid is at a second pressure. The commutator 10 is provided with an actuator 50 commutable between a closed position wherein fluid flow between the first and second openings is prevented and, an open position wherein fluid flow is enabled in a first direction from a first opening 18 to a second opening 20 when the first pressure is superior to the second pressure, or in a second direction from the second opening 20 to the first opening 18 when the second pressure is superior to the first pressure. The arrangement may be used in a high pressure fuel injection or fuel delivery system in order to save energy during variable load conditions, by transferring fuel at high pressure to and from a reservoir to meet instantaneous demand.

Description

BIDIRECTIONAL HP VALVE

TECHNICAL FIELD

The present invention relates to a hydraulic commutator adapted to be arranged within a high pressure circuit, such as a diesel fuel injection equipment.

BACKGROUND OF THE INVENTION

Hydraulic commutator adapted to open or close a fluid connection within a hydraulic circuit and, when in open position, enabling flow in either direction of the circuit exist in very different embodiments. The performance of the commutator is basically measured by three parameters: the amount of fluid leakage when in closed position, the maximum pressure under which the commutator can operate between said open and closed states and, the speed at which said switch can occur.

Hybrid diesel fuel injection equipment, such as disclosed in application PCT/EP2014/068161 requires a commutator aiming at zero leakage, able to operate under 2500 bars, with a burst pressure of 3500 bars for safety purposes, that is adapted to commute at high frequency within few milliseconds and that is able to flow in either direction depending on the pressures from each side

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to resolve the above mentioned problems in providing a high pressure hydraulic commutator adapted to be arranged in a high pressure fluid equipment between a first high pressure circuit wherein fluid is at a first pressure and a second high pressure circuit wherein fluid is at a second pressure. The commutator has a first opening for connection with the first circuit and a second opening for connection with the second circuit.

Specifically the commutator is provided with an actuator controllable to commute the commutator between a closed state and an open state by switching a valve member between a closed position wherein fluid flow between the first and second openings is prevented and, an open position wherein fluid flow is enabled in a first direction from the first opening to the second opening when the first pressure is superior to the second pressure or in a second direction from the second opening to the first opening when the second pressure is superior to the first pressure.

Also, the hydraulic commutator comprises a first inlet check valve, a second inlet check valve, a first outlet check valve and, a second outlet check valve, and also an electrically controllable main valve. In the first direction of flow, the first inlet check valve and second outlet check valve open while the second inlet check valve and first outlet check valve remain closed and wherein, in the second direction of flow the first inlet check valve and second outlet check valve remain closed while the second inlet check valve and first outlet check valve open.

Also, the electrically controllable main valve is arranged between the first inlet check valve and the second outlet check valve and also between the second inlet check valve and the first outlet check valve.

Also, the electrically controllable main valve comprises a valve housing defining a chamber provided with a chamber inlet and with a chamber outlet, said chamber outlet being surrounded by a fixed seating face and, a moveable valve member arranged in said chamber and defining a valve seating face adapted to cooperate with the fixed seating face in order to open or to close the chamber outlet.

Also, whatever the flow direction in the commutator is, in the chamber fluid flows from the inlet to the outlet.

Also, the commutator is able to operate and adapted to receive all first and second pressures from 0 up to 3000 bars.

Also, the commutation time between the open state and the closed state of the commutator is shorter than 1ms, and preferably shorter than 100 microseconds and at best shorter than 10 micro-seconds.

Also, the commutator is adapted to commute at any frequency up to 1000Hz.

Also, said hydraulic commutator is arranged in series between a first high pressure circuit and a second high pressure circuit.

Also, the equipment is a hybrid fuel injection equipment of a diesel internal combustion engine, the injection equipment comprising a high pressure pump connected via a main line to a high pressure manifold to which is connected at least one fuel injector, the injection equipment further comprising a high pressure reservoir. The hydraulic commutator is arranged in a storage line joining the outlet of the high pressure pump to the high pressure reservoir, said hydraulic commutator enabling, when in open state, pressurized diesel fuel flowing out of the high pressure pump to be delivered to the reservoir where it can be stored under pressure.

In another alternative, the equipment is a hybrid fuel injection equipment of a diesel internal combustion engine comprising a high pressure pump connected via a main line to a high pressure manifold to which is connected at least one fuel injector, the injection equipment further comprising a high pressure reservoir and the hydraulic commutator arranged in a storage line connected directly to the high pressure manifold. The hydraulic commutator enables, when in open state, pressurized diesel fuel flowing out of the high pressure pump to enter the manifold then to flow to the reservoir where it can be stored under pressure.

Also, when in open state of the commutator, the pressurized fuel contained in the reservoir can flow to the high pressure manifold.

The invention further extends to an electronic control unit adapted to control a high pressure fluid equipment as previously described.

The invention further extends to a software able to execute the steps of a control method for controlling a high pressure fluid equipment when said software is loaded onto an electronic control unit as mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is now described by way of example with reference to the accompanying drawings in which:

Figure 1 is a section of a hydraulic commutator as per the invention.

Figures 2 and 3 represent the commutator of figure 1 under two different configurations.

Figure 4 is an exemplary hydraulic circuit wherein is arranged the commutator of figure 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In reference to the figures 1, 2 and 3 is described an exemplary embodiment of a hydraulic commutator 10 as per the invention.

The commutator 10 comprises a body 12 adapted to be fixed via fixing ears 14 and which defines internal hydraulic circuits 16 joining a first opening 18, left of the figure, to a second opening 20, right of the figures.

The orientation of the figures is utilized without any intention to limit or bind the invention to a specific orientation therefore, words such as “left, right, horizontal, up, down..will be utilized simply to ease and clarify the description.

Inside the body 12, the first opening 18 joins a first T-junction 22 leading to a first vertical conduit 24 extending between an inlet end 26, top on the figure, and an outlet end 28, bottom on the figure. As said above, in alternative embodiments, the “vertical” conduit can be arranged otherwise to accommodate another design.

Similarly, the second opening 20 joins a second T-junction 30 leading to a second vertical conduit 32 extending between an inlet end 34, top on the figure, and an outlet end 36, bottom on the figure.

An inlet transverse conduit 38, horizontal on the top of the figure, joins the inlet ends 26, 34, of the first 24 and second 32 conduits and, on the opposite, an outlet transverse conduit 40 joins the outlet ends 28, 36, of the first 24 and second 32 conduits. A central chamber C provided with a chamber inlet 42 and a chamber outlet 44 is arranged in the body 12. The chamber inlet 42 extends between the inlet conduit 38 where it opens between the inlet ends 26, 34, of the first 24 and second 32 conduits and the chamber C and, the chamber outlet 44 extends between the outlet conduit 40 where it opens between the outlet ends 28, 36, of the first 24 and second 32 conduits, and the chamber C. In the chamber C, the body 12 defines a fixed conical seating face 46 surrounding the opening of the chamber outlet 44. In alternatives, the seating face defined as “conical” can be given another shape such as a portion of a torus or a combination of several shapes.

Inside the chamber C is arranged a main valve 48 comprising a fixed actuator 50, a movable valve member 52 and a compression spring 54. In the nonlimiting embodiment presented, the actuator 50 is a solenoid with electrical leads 56 joining an external connector 58, said solenoid 50 generating a magnetic field M when it is energized. The valve member 52 comprises a shaft member 60, one end of which being provided with a valve seating face 62 adapted to cooperate with the fixed seating face 46 of the chamber outlet and which, opposite end 64 is crimped into a disc-like magnetic armature 66 adapted to cooperate with the solenoid 50. As visible on the figures, the disc-like magnetic armature 66 spreads across the section of the chamber C dividing the chamber C in an inlet side subchamber and an outlet side sub-chamber. The disc-like magnetic armature 66 is provided with through apertures 67 joining said sub-chambers. Multiple alternative embodiments, such as a peripheral clearance, are possible to create a fluid communication between said sub-chambers.

The spring 54 is compressed between said opposite crimped end 64 of the shaft member and an upper, or inlet, face 68 of the chamber C so that said spring 54 permanently urges the valve member 52 toward a closed position CP of the chamber outlet 44, that is defined when the valve seating face 62 is a sealing contact against the fixed seating face 46.

In a non-represented alternative, the valve member 52 could comprise, instead to the solenoid, a piezo-actuator, or a magneto-restrictive actuator directly connected to the shaft member 60.

The commutator 10 further comprises a first inlet check valve 70 arranged in an enlarged portion 72 of the first conduit 24 between the first T-junction 22 and the inlet end 26 of said first conduit. The first inlet check valve 70 comprises a ball 74 biased by a spring 76 against a fixed conical seat 78 defined in said enlarged portion 72, around the opening of the first conduit 24 closest to the first T-junction 22.

Similarly, a second inlet check valve 80 is arranged in an enlarged portion 82 of the second conduit 32 between the second T-junction 30 and the inlet end 34 of said second conduit. Said second inlet check valve 80 comprises a ball 84 biased by a spring 86 against a fixed conical seat 88 defined in said enlarged portion 82, around the opening of the second conduit 32 closest to the second T-junction 30.

Also, a first outlet check valve 90 is arranged in another enlarged portion 92 of the first conduit 24 between the first T-junction 22 and the outlet end 28 of said first conduit. The first outlet check valve 90 comprises a ball 94 biased by a spring 96 against a fixed conical seat 98 defined in said enlarged portion 92, around the opening of the first conduit 24 away from the first T-junction 22.

Finally, a second outlet check valve 100 is arranged in another enlarged portion 102 of the second conduit 32 between the second T-junction 30 and the outlet end 36 of said second conduit. The second outlet check valve 100 comprises a ball 104 biased by a spring 106 against a fixed conical seat 108 defined in said enlarged portion 102, around the opening of the second conduit 32 away from the second T-junction 30.

In the embodiment presented on figure 1 all four check valves 70, 80, 90, 100, are oriented in the same direction, the ball are downwardly biased in a closed position and can only open when the ball is moved upwardly.

Alternatively to an arrangement in the vertical first 24 and second 32 conduits, the check valves 70, 80, 90, 100, could be arranged in the horizontal inlet 38 and outlet 40 transverse conduits with same fluid orientation as presented.

The operation of the commutator 10 is now described.

Figure 1 represents a closed state CS wherein no fluid can flow between the first opening 18 and the second opening 20 since the valve member 52 is in closed position CP, the valve seating face 62 of the shaft member being in sealing contact against the fixed seating face 46 of the body 12.

Figures 2 and 3 respectively represent a first open state OS1 and a second open state OS2 of the commutator, the solenoid 50 being energized therefore generating the magnetic field M attracting the magnetic armature 66 and upwardly moving the shaft member 52 into an open position OP therefore opening a fluid communication between the first opening 18 and the second opening 20.

In the first open state OS1, figure 2, a fluid pressure on the side of the first opening 18 is superior to the fluid pressure on the side of the second opening 20, the arrows A1 identify a first flow direction followed by the fluid which naturally tends to flow from the first opening 18 to the second opening 20.

The fluid enters the commutator 10 by the first opening 18 then in the first conduit 24, the fluid is obliged to move upward toward the first inlet check valve 70. Indeed said first inlet check valve 70 is pushed in an open position Oil by the fluid flow that further compresses the spring 76. In the opposite direction, the fluid flow is blocked and cannot go downward since the fuel pressure across the first outlet check valve 90 combined to the spring force forbids any flow in that direction. Furthermore, the pressure of the fluid flow further biases said check valve 90 in a closed position COl since, as it is detailed afterward, on the opposite side of said check valve 90, in the outlet transverse conduit 40, the pressure is slightly lower because of the passage of the fuel flow through the first inlet check valve 70 and through the main valve 48.

Once the fluid has passed the first inlet check valve 70, the flow can only enter the chamber C since, as visible on the figures, the second inlet check-valve 80 is oriented to prevent such a flow and also because of for similar reasons of fuel pressure combined to spring force, as explained above for the first outlet check valve 90. The flow enters chamber C via the chamber inlet 42 and flows around the armature or through the apertures 67 to reach the chamber outlet 44 that is open. The flow then exits the chamber C and can only go toward the second outlet check valve 100 since, as explained above for combined reasons of pressure differences and spring force, the first outlet check valve 90 forbids flow in the opposite direction. The second outlet check valve 100 that is in closed position C02 is pushed in an open position 002 enabling the fluid to flow toward the second opening 20 where it exits the commutator 10. It is clear that the second outlet check valve 100 is also subject to combined forces of pressures and spring force and, to move into the open position 002, the force generated on the ball 108 by the fuel pressure in the transverse conduit 40 has to overcome the sum of forces generated on said ball 108 by the spring 106 and by the pressure in the second conduit 32.

In the second open state OS2, figure 3, a fluid pressure on the side of the second opening 20 is superior to the fluid pressure on the side of the first opening 18, the arrows A2 identify the second flow direction followed by the fluid which naturally tends to flow from the second opening 20 to the first opening 18.

The fluid enters the commutator 10 by the second opening 20 then in the second conduit 32 is obliged to move upward toward the second inlet check valve 80. Indeed said second inlet check valve 80 is pushed in an open position 012 by the fluid flow that further compresses the spring 86. In the opposite direction, the fluid flow is blocked and cannot go downward since the second outlet check valve 100 forbids any flow in that direction and the pressure of the fluid flow further biases said check valve 100 in the closed position C02. Similarly to the previous explanation, on the opposite side of said check valve 100, in the outlet transverse conduit 40, the pressure is slightly lower because of the passage of the fuel flow through the second inlet check valve 80 and through the main valve 48.

Once the fluid has passed the second inlet check valve 80, the flow can only enter the chamber C since, as visible on the figure, the first inlet check-valve 70 is oriented to prevent such a flow. The flow enters chamber C via the chamber inlet 42 and flows around the armature or through the apertures 67 to reach the chamber outlet 44 that is open. The flow then exits the chamber C and can only go toward the first outlet check valve 90 since, the second outlet check valve 100 forbids flow in the opposite direction. The first outlet check valve 90 that is in closed position COl is easily pushed in an open position OOl enabling the fluid flow toward the first opening 18 where it exits the commutator 10.

The complementary arrangement of the conical fixed seating face 46 surrounding the chamber outlet 44 with the shaft member valve seating face 62 ensures that in closed position CP of the main valve 48 no flow is enabled to leak from opening to the other.

Furthermore, the solenoid 50 solution presented, as well as the piezoelectric or magneto-restrictive actuator mentioned, enables high frequency and fast commuting time of said main valve 48. A hybrid diesel fuel injection equipment 120 of an internal combustion engine is now presented on figure 4 as an example of use of the commutator 10. The equipment 120 comprises a low pressure system 122 wherein diesel fuel sucked in a tank by a transfer pump is flown through a filter and delivered to a high pressure system 124. Said high pressure system 124 comprises an inlet metering valve 126, a high pressure pump 128 from the outlet of which fuel can follow a main line 130 leading to a high pressure manifold 132, also known as a common rail 132, which internal pressure is measured by a pressure sensor 134. To said common rail 132 are fluidly connected a plurality of injectors 136, four in the present example. From the outlet of the high pressure pump 128 the high pressure fuel flow can also follow a storage line 138 comprising the commutator 10 and a high pressure reservoir 140 which internal pressure is measured by another pressure sensor 142.

The equipment 120 further comprises a low pressure return line collecting low pressure fuel from the injectors and from the rail 132 and sending it back to the tank.

In the system represented on figure 4 the outlet of the high pressure pump 128 connects via a T-junction to the common rail 132 and also to the commutator 10.

In a first alternative not represented, the T-junction is replaced by a first line directly connecting the outlet of the high pressure pump 128 to the common rail 132 and, by second line directly connecting the connector 10 also to the common rail 132. In this alternative, the pressurized fuel flowing from the pump 128 to the high pressure reservoir 140 has first to enter the common rail 132 via the first line, then to exit said rail 132 via the second line.

In a second alternative not represented either, the system is “rail-less” meaning that the common rail 132 is removed and replaced by a simple high pressure pipe inter-connecting in parallel, or sequentially, the injectors 136. In this second alternative the high pressure pump 128 and reservoir 140 can be connected to said high pressure pipe in a similar way as in figure 4, with a T-junction or, as described above via independent first and a second lines. For instance, the first line can be connected at one end of said high pressure pipe and, the second line could be connected at the other end.

The hybrid equipment 120 is controlled by an electronic control unit [ECU] 144 which receives signals representative of the engine demand in term of torque, power, speed, RPM... as well as signals from the pressure sensors 134, 142. The ECU 144 computes relevant command signals sent to the inlet metering valve 126, to the injectors 136, and to the commutator 10, and to the transfer pump in order to meet said engine demand.

Three operational states are now detailed.

In a “normal mode” of operation, for instance when a vehicle is driven at constant speed, the commutator 10 is in the closed state CS and high pressure fuel is directly delivered by the high pressure pump 128 via the main line 130 to the common rail 132 then to the injectors 136.

When the vehicle brakes, the engine demand drops to the point that fuel injection is no longer required and is prevented. This also occurs in a so-called “foot-off’ situation or deceleration of the vehicle. The fuel injection equipment 120 switches to a “recharge mode” of operation where the inlet metering valve 126 is commanded wide open, the main valve 48 is switched to the open position OP, and because of the high pressure on the pump side the commutator 10 naturally set in the first open state OS1, figure 2, where high pressure fuel enters the reservoir 140.

Conclusive tests have been performed with a reservoir 140 having about 2 1L capacity and a common rail 132 of about 15 cm so, in said “recharge state” although both main 130 and storage 138 lines are open the majority of the fuel flow enters the reservoir 140 wherein pressure rises to a maximum threshold at which the commutator 10 is commanded to switch back to the closed state CS.

During said tests the internal pressure of the 1L capacity reservoir 140 rises from 1 bar to 2000 bars by adding approximately 70 cm of fuel.

When the vehicle accelerates again, the engine demand in high pressure fuel increases and the fuel injection equipment 120 switches to a “restore mode” of operation wherein the inlet metering valve 126 is closed forbidding entry of fuel into the high pressure pump 128. The main valve 48 remains in the open position OP and, because of the higher pressure in the reservoir 140 than in the common rail 132, the commutator 10 naturally set in the second open state OS2, figure 3, where pressurized fuel can flow off the reservoir 140 and enter the common rail 132. Considering the respective volumes of the reservoir 140 and of the rail 132, the pressure in the rail 132 can easily meet the engine demand by utilizing fuel pressurized during the “recharge mode”.

Although the three operational modes have been described sequentially, the performance required to be met by the commutator 10 are to be appreciated in a real dynamic situation. For instance, should operational high pressure ranges from 0 to 3000 bars, for safety purposes a burst pressure of at least 4000 bars is required. Also, when the pressure in the reservoir 140 is maximum and the fuel equipment 120 operates in “normal mode” where the commutator 10 is in the closed state CS, it is important that the commutator 10 sealingly closes the reservoir 120 and does not leak since, in the subsequent phase of operation the pressurized fuel in the reservoir 140 will be required.

Furthermore, during the “restore mode” of operation, in a classical multicylinder engine, the commutator 10 may be commanded to open and close rapidly. For instance, the inlet metering valve 126 being closed, when a first injection occurs, a fuel quantity is injected and the rail pressure drops. The commutator 10 is then commanded to open in order for pressurized fuel to flow from the reservoir 140 into the rail 132 and compensate for whatever quantity has been injected. Once the rail pressure has raised back to the engine demand, the commutator 10 closes again and, a second injection may occur. This means that the commutator 10 is requested to open and close between each injection in order for the common rail 132 to always be at the same pressure when an injection happens and then, no one injector 136 gets a lower pressure than another.

In a four cylinder diesel engine running at 3000 RPM, one injection occurs every 10ms, or at frequency of about 100Hz. The commutator 10 has to open and close at even a faster rate.

To enable the dynamic operation of the hybrid fuel injection equipment 120, the hydraulic commutator 10 is able to operate with pressures on either first opening 18 or second opening 20 ranging anywhere between 0 and 3000 bars.

Also, to enable dynamic performances, the commutation time between the open state and the closed state of the commutator 10 is shorter than 10 microseconds. A longer time of 100 micro-seconds or even 1ms may still be acceptable for a lesser dynamic operation of the hybrid equipment 120.

Furthermore, the dynamic operation requires constant switching of the commutator 10 which can operate to a frequency of 1000 Hz and, preferably between the first opening 18 and the second opening 20 the minimum pressure difference should range between 10 and 20 bars.

Thanks to the high performance of the commutator 10 energy spent during deceleration or foot-off or braking can be stored and utilized at a later stage.

LIST OF REFERENCES C central chamber M magnetic field CS closed state of the commutator 051 first open state of the commutator 052 second open state of the commutator A1 first flow direction A2 second flow direction OP open position of the main valve CP closed position of the main valve 011 open position of the first inlet check valve CI1 closed position of the first inlet check valve 002 open position of the second outlet check valve C02 closed position of the second outlet check valve 012 open position of the second inlet check valve CI2 closed position of the second inlet check valve 001 open position of the first outlet check valve C01 closed position of the first outlet check valve 10 commutator 12 body 14 fixing ears 16 internal hydraulic circuits 18 first opening 20 second opening 22 first T junction 24 first conduit 26 inlet end of the first conduit 28 outlet end of the first conduit 30 second T-junction 32 second conduit 34 inlet end of the second conduit 36 outlet end of the second conduit 38 inlet transverse conduit 40 outlet transverse conduit 42 chamber inlet 44 chamber outlet 46 fixed seating face 48 main valve 50 actuator / solenoid 52 valve member 54 spring 56 electrical leads 58 connector 60 shaft member 62 valve seating face 64 crimped end of the shaft 66 magnetic armature 67 apertures 68 inlet face of the chamber 70 first inlet check valve 72 enlarged portion of the first conduit 74 ball / check valve member 76 spring 78 fixed conical seat 80 second inlet check valve 82 enlarged portion of the second conduit 84 ball / check valve member 86 spring 88 fixed conical seat 90 first outlet check valve 92 another enlarged portion of the first conduit 94 ball / check valve member 96 spring 98 fixed conical seat 100 second outlet check valve 102 another enlarged portion of the second conduit 104 ball / check valve member 106 spring 108 fixed conical seat 120 Hybrid diesel fuel equipment 122 low pressure system 124 high pressure system 126 inlet metering valve 128 high pressure fuel pump 130 mainline 132 manifold / common rail 134 rail pressure sensor 136 injector 138 storage line 140 high pressure reservoir 142 reservoir pressure sensor

144 electronic control unit ECU

Claims

CLAIMS:

1. High pressure hydraulic commutator (10) adapted to be arranged in a high pressure fluid equipment between a first high pressure circuit wherein fluid is at a first pressure and a second high pressure circuit wherein fluid is at a second pressure, the commutator (10) having a first opening (18) for connection with the first circuit and a second opening (20) for connection with the second circuit, characterized in that the commutator (10) is provided with an actuator (50) controllable to commute the commutator (10) between a closed state (CS) and an open state (OS1, OS2) by switching a valve member (52) between a closed position (CP) wherein fluid flow between the first and second openings is prevented and, an open position (OP) wherein fluid flow is enabled in a first direction (Al) from the first opening (18) to the second opening (20) when the first pressure is superior to the second pressure or, in a second direction (A2) from the second opening (20) to the first opening (18) when the second pressure is superior to the first pressure.
2. Hydraulic commutator (10) in the preceding claim comprising a first inlet check valve (70), a second inlet check valve (80), a first outlet check valve (90) and, a second outlet check valve (100), and an electrically controllable main valve (48), wherein, in the first direction (Al) of flow, the first inlet check valve (70) and second outlet check valve (100) open while the second inlet check (80) valve and first outlet check valve (90) remain closed and wherein, in the second direction (A2) of flow the first inlet check valve (70) and second outlet check valve (100) remain closed while the second inlet check valve (80) and first outlet check valve (90) open.
3. Hydraulic commutator (10) as claimed in claim 2 wherein the electrically controllable main valve (48) is arranged between the first inlet check valve (70) and the second outlet check valve (100), and also between the second inlet check valve (80) and the first outlet check valve (90).
4. Hydraulic commutator (10) as claimed in claim 3 wherein the electrically controllable main valve (48) comprises a valve housing defining a chamber (C) provided with a chamber inlet (42) and with a chamber outlet (44), said chamber outlet (44) being surrounded by a fixed seating face (46) and, a moveable valve member (52) arranged in said chamber (C) and defining a valve seating face adapted to cooperate with the fixed seating face in order to open or to close the chamber outlet (44).
5. Hydraulic commutator (10) as claimed in claim 4 wherein, whatever the flow direction in the commutator is, in the chamber fluid flows from the inlet (42) to the outlet (44).
6. Hydraulic commutator (10) as claimed in any one of the preceding claims wherein the commutator is able to operate and adapted to receive all first and second pressures from 0 up to 3000 bars.
7. Hydraulic commutator (10) as claimed in any one of the preceding claims wherein the commutation time between the open state and the closed state of the commutator is shorter than 1ms, and preferably shorter than 100 micro-seconds and at best shorter than 10 micro-seconds.
8. Hydraulic commutator (10) as claimed in any one of the preceding claims in the preceding claim wherein the commutator is adapted to commute at any frequency up to 1000Hz.
9. High pressure fluid equipment (120) comprising a hydraulic commutator (10) as claimed in any one of the preceding claims, said hydraulic commutator (10) being arranged in series between a first high pressure circuit and a second high pressure circuit.
10. High pressure fluid equipment (120) as claimed in claim 9 wherein said equipment is a hybrid fuel injection equipment of a diesel internal combustion engine, the injection equipment comprising a high pressure pump (128) connected via a main line (130) to a high pressure manifold (132) to which is connected at least one fuel injector (136), the injection equipment (120) further comprising a high pressure reservoir (140) and, the hydraulic commutator (10) arranged in a storage line (138) joining the outlet of the high pressure pump to the high pressure reservoir, said hydraulic commutator (10) enabling, when in open state, pressurized diesel fuel flowing out of the high pressure pump (128) to be delivered to the reservoir (140) where it can be stored under pressure.
12. High pressure fluid equipment (120) as claimed in claim 9 wherein said equipment is a hybrid fuel injection equipment of a diesel internal combustion engine, the injection equipment comprising a high pressure pump (128) connected via a main line (130) to a high pressure manifold (132) to which is connected at least one fuel injector (136), the injection equipment (120) further comprising a high pressure reservoir (140) and the hydraulic commutator (10) arranged in a storage line (138) connected directly to the high pressure manifold (132), said hydraulic commutator (10) enabling, when in open state, pressurized diesel fuel flowing out of the high pressure pump (128) to enter the manifold (132) then to flow to the reservoir (140) where it can be stored under pressure.
13. High pressure fluid equipment (120) as claimed in any one of the claims 11 or 12 wherein when in open state of the commutator (10) pressurized fuel contained in the reservoir (140) can flow to the high pressure manifold (132).
14. Electronic control unit (144) adapted to control a high pressure fluid equipment (120) as claimed in any one of the claims 9 to 13.
15. Software able to execute the steps of a control method for controlling a high pressure fluid equipment (120) when said software is loaded onto an electronic control unit (144) as claimed in claim 14.