CN114635803A

CN114635803A - Aircraft engine fuel system and aircraft engine

Info

Publication number: CN114635803A
Application number: CN202011489414.7A
Authority: CN
Inventors: 孙逸宇; 单亚杰; 方晓骏; 仲金金
Original assignee: AECC Commercial Aircraft Engine Co Ltd
Current assignee: AECC Commercial Aircraft Engine Co Ltd
Priority date: 2020-12-16
Filing date: 2020-12-16
Publication date: 2022-06-17
Anticipated expiration: 2040-12-16
Also published as: CN114635803B

Abstract

The present disclosure relates to an aeroengine fuel system and aeroengine, fuel system includes: shutting off the valve at high pressure; an over-rotation solenoid valve; the over-rotation executing valve at least comprises a first cavity, a third cavity and a fourth cavity, and the first lining is provided with a first oil port, a third oil port, a fourth oil port and a fifth oil port; the fifth oil port is communicated with the fourth cavity and introduces fuel oil with a first pressure value, the fourth oil port is communicated with the third cavity and the control cavity of the high-pressure shutoff valve, the third oil port introduces fuel oil with a second pressure value, and the first pressure value is larger than the second pressure value; under the over-rotation triggering state, the over-rotation electromagnetic valve is switched on to enable the fuel oil entering the second pressure value in the first cavity to move to the first limit position towards the first cavity under the action of pressure difference between the two ends, the fourth oil port is communicated with the third oil port through the third cavity, and the fuel oil of the second pressure value is led to the control cavity to enable the high-pressure shutoff valve to be shut off; under the over-rotation locking state, the over-rotation electromagnetic valve is turned off, and the first piston is kept still under the action of pressure difference.

Description

Aircraft engine fuel system and aircraft engine

Technical Field

The disclosure relates to the technical field of aircraft engines, in particular to an aircraft engine fuel system and an aircraft engine.

Background

When an aircraft engine fuel system works, an aircraft engine control system is required to have an over-running protection function according to airworthiness related requirements in order to ensure the working safety of the aircraft engine. After the aircraft engine triggers the over-rotation instruction, the fuel system can cut off fuel supplied to the combustion chamber, oil cutting action is rapidly completed to stop the engine, and the over-rotation protection function and the fuel control function are mutually independent.

Therefore, the fuel system needs to ensure that the fuel system can complete the oil cutting action when the over-rotation command is triggered at any position of the metering valve, and after the over-rotation command is cancelled, the fuel system is ensured to be in the oil cutting state before the metering valve returns to the initial position.

Disclosure of Invention

The embodiment of the disclosure provides an aircraft engine fuel system and an aircraft engine, which can improve the safety of the aircraft engine during working.

According to an aspect of the present disclosure, there is provided an aircraft engine fuel system comprising:

a high pressure shutoff valve having an on state and an off state, configured to control the on-off state of supplying fuel to the combustion chamber;

an over-rotation solenoid valve having an on state and an off state; and

the over-rotation execution valve comprises a first lining and a first piston, the first piston is movably arranged in the first lining, at least a first cavity, a third cavity and a fourth cavity are formed between the first piston and the first lining, and a first oil port, a third oil port, a fourth oil port and a fifth oil port are formed in the first lining; the fifth oil port is communicated with the fourth cavity and is configured to selectively introduce fuel oil with a first pressure value, the fourth oil port is communicated with the third cavity and the control cavity of the high-pressure shutoff valve, the third oil port introduces fuel oil with a second pressure value, and the first pressure value is larger than the second pressure value;

under the over-rotation triggering state, the over-rotation electromagnetic valve is switched to the connection state to enable the fuel oil with the second pressure value to enter the first cavity, the fuel oil with the first pressure value is introduced into the fourth cavity, the first piston moves to the first limit position towards the first cavity under the action of the pressure difference between the first cavity and the fourth cavity at the two ends, and the fourth oil port is communicated with the third oil port through the third cavity to enable the fuel oil with the second pressure value to be introduced into the control cavity to enable the high-pressure shutoff valve to be in the shutoff state; and under the over-rotation locking state, the over-rotation electromagnetic valve is switched to the off state, and the first piston keeps the position unchanged under the action of the pressure difference between the first cavity and the fourth cavity.

In some embodiments, the aircraft engine fuel system further comprises:

a low-pressure pump and a high-pressure pump configured to supply oil to the combustion chamber;

the first pressure value is consistent with the outlet pressure of the high-pressure pump, and the second pressure value is consistent with the outlet pressure of the low-pressure pump.

In some embodiments, a second cavity is further formed between the first piston and the first bushing, the first cavity, the second cavity, the third cavity and the fourth cavity are sequentially arranged, and a second oil port is further formed in the first bushing; the over-rotation solenoid valve is configured to provide fuel oil at a second pressure value to the second chamber through the second oil port in an over-rotation triggering state and provide fuel oil at a first pressure value to the second chamber through the second oil port in an over-rotation locking state.

In some embodiments, the high pressure shut-off shutter comprises a control valve body and an actuating valve body, the control valve body comprises a second bushing and a second piston, the second piston is movably arranged in the second bushing and divides a control cavity in the control valve body into a first control cavity and a second control cavity, the first control cavity introduces fuel oil with a first pressure value and is communicated with the third cavity through a fourth oil port, and the second control cavity has the first pressure value;

and under the over-rotation triggering state, the first control cavity introduces fuel oil with a second pressure value through the third cavity, so that the second piston moves to close the action valve body.

In some embodiments, the aircraft engine fuel system further comprises a metering valve and a fuel classification valve, the high-pressure shutoff valve comprises a control valve body and an action valve body, the action valve body comprises a third bushing and a third piston, the third piston is movably arranged in the third bushing and divides a cavity in the third bushing into a working cavity and a spring cavity, and the third bushing is provided with a first working oil port connected with the metering valve and a second working oil port connected with the fuel classification valve;

the first working oil port is communicated with the second working oil port in a normal working state; under the over-rotation triggering state, the third piston moves to enable the first working oil port and the second working oil port to be separated under the action of the control valve body, so that the action valve body is turned off.

In some embodiments, the aircraft engine fuel system further includes a metering valve including a fourth bushing and a fourth piston, the fourth piston is movably disposed in the fourth bushing, and the cavity in the fourth bushing is sequentially divided into a fifth cavity, a sixth cavity, a seventh cavity and an eighth cavity, the fourth bushing is provided with a sixth oil port, a seventh oil port, an eighth oil port, a ninth oil port, a tenth oil port and an eleventh oil port, the sixth oil port and the eleventh oil port are respectively communicated with the fifth cavity and the eighth cavity, and the fuel oil at the second pressure value or the third pressure value is selectively introduced to move the fourth piston; the seventh cavity is communicated with the fourth cavity through a ninth oil port and a fifth oil port, a throttle valve is arranged on a communicated passage, and the adjusting pressure of the throttle valve is a first pressure value; and the tenth oil port is filled with fuel oil with a second pressure value.

In some embodiments, in the initial reset state, the seventh oil port and the eighth oil port are separated to shut off the metering valve, and the fourth chamber is communicated with the tenth oil port through the seventh chamber and has a second pressure value; and in other states, the seventh oil port and the eighth oil port are communicated through the sixth cavity to enable the metering valve to be switched on, and the seventh cavity is switched off to be communicated with the tenth oil port to enable the fourth cavity to have a first pressure value.

In some embodiments, the aircraft engine fuel system further comprises a metering shutter connected upstream of the high pressure shut-off shutter and a fuel staging valve connected downstream of the high pressure shut-off shutter, the aircraft engine fuel system having a normal operating state, an over-rotation triggered state, an over-rotation locked state and an initial reset state, wherein:

under the normal working state, the over-rotation electromagnetic valve is in a turn-off state, the metering valves are all in a turn-on state, the first piston is in a second limit position, and the high-pressure turn-off valve is in a turn-on state;

under the over-rotation triggering state, the over-rotation electromagnetic valve is in a connection state, the metering valves are in connection states, the first piston is in a first limit position, and the high-pressure shutoff valve is in a shutoff state;

under the over-rotation locking state, the over-rotation electromagnetic valve is in a disconnection state, the metering valves are in a connection state, the first piston is in a first limit position, and the high-pressure shutoff valve is in a disconnection state;

under the initial reset state, the over-rotation electromagnetic valve and the metering valve are both in a turn-off state, the metering valve is in a turn-off state, the first piston is in a first limit position, the high-pressure turn-off valve is in a turn-off state, the pressure of the fourth cavity is switched to a second pressure value, and the first piston moves through pressure difference to recover to a normal working state.

According to another aspect of the present disclosure, an aircraft engine is provided, comprising the aircraft engine fuel system of the above embodiment.

The aircraft engine fuel system has an over-rotation protection function, after the rotating speed of the aircraft engine exceeds a preset rotating speed, an over-rotation instruction is triggered, the fuel system can cut off fuel oil supplied to a combustion chamber through a high-pressure shut-off valve, and the fuel oil cutting action is rapidly completed to stop the engine; moreover, the overtravel execution valve with the hydraulic locking function can avoid oscillation caused by pressure fluctuation in a large flow state, improve the reliability of the overtravel oil cutting function, maintain the pressure of a fuel system and ensure the normal servo action of the fuel system; in addition, the structure is simple, the weight is light, the volume and the weight of the accessory shell can be reduced, and the thrust-weight ratio of the engine is improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the disclosure and together with the description serve to explain the disclosure and not to limit the disclosure. In the drawings:

FIG. 1 is a system schematic of a typical aircraft engine fuel system;

FIG. 2 is a schematic diagram of a system having an over-rotation lockout function in the fuel system of an aircraft engine according to the present disclosure;

FIG. 3 is a schematic view of the aircraft engine fuel system with over-rotation lockout function of FIG. 2 in a normal operating condition;

FIG. 4 is a schematic view of the aircraft engine fuel system with over-rotation lockout of FIG. 2 in an over-rotation triggered state;

FIG. 5 is a schematic view of the aircraft engine fuel system having an over-rotation lockout function of FIG. 2 in an over-rotation lockout condition;

FIG. 6 is a schematic view of the aircraft engine fuel system with over-rotation lockout function of FIG. 2 in an initial reset state.

Detailed Description

The present disclosure is described in detail below. In the following paragraphs, different aspects of the embodiments are defined in more detail. Aspects so defined may be combined with any other aspect or aspects unless clearly indicated to the contrary. In particular, any feature considered to be preferred or advantageous may be combined with one or more other features considered to be preferred or advantageous.

The terms "first", "second", and the like in the present disclosure are merely for convenience of description to distinguish different constituent elements having the same name, and do not denote a sequential or primary-secondary relationship.

In the description of the present invention, it is to be understood that the terms "inner", "outer", "upper", "lower", "left", and "right", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention, but do not indicate or imply that the device referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the scope of the present invention.

The principle of an aircraft engine fuel system is shown in figure 1, and comprises: the fuel injection valve comprises a low-pressure pump 1, a high-pressure pump 2, a constant-pressure valve 3, an actuating part 4, a high-pressure shutoff valve 5, a fuel grading valve 6, a first group of fuel nozzles 7, a second group of fuel nozzles 8, a metering valve 9, a differential pressure valve 10 and an oil return valve 11.

After the aircraft incoming oil is pressurized by the low-pressure pump 1 and the high-pressure pump 2, the aircraft incoming oil enters a fuel manifold and a fuel nozzle through the metering valve 9 and the high-pressure shutoff valve 5 and is supplied to an engine combustion chamber. The metering valve 9 is used for metering the fuel quantity to the combustion chamber of the engine; the high-pressure shutoff valve 5 is used for keeping the system at a sufficient minimum servo pressure and cutting off fuel to an engine combustion chamber after the engine stops; the differential pressure valve 10 is used for ensuring that the front and back differential pressure of the metering valve 9 is constant, so that the fuel quantity to a combustion chamber can be controlled by controlling the position of the metering valve 9; the return valve 11 is used to return fuel supplied by the high pressure pump 2 in excess of the engine demand to the rear of the low pressure pump 1. In order to improve the atomization effect of the fuel nozzle, fuel is supplied to a part of nozzles of the combustion chamber when the flow rate of the combustion chamber is small, and the fuel is supplied to all nozzles of the combustion chamber when the flow rate of the combustion chamber is large.

The low pressure Pb of the system is formed after the aircraft incoming oil is pressurized by the low pressure pump 1, and the high pressure oil Ps is formed after the fuel oil is pressurized by the high pressure pump 2. One path of high-pressure oil is supplied to a constant-pressure valve 3 of the servo system and used for regulating the constant-pressure oil Pc; the other path is supplied to the metering valve 9, the pressure in front of the metering valve 9 is P1, the pressure behind the metering valve 9 is P2, the differential pressure valve 10 senses the pressure in front of and behind the metering valve 9, and the differential pressure in front of and behind the metering valve 9 is kept constant by controlling the oil return valve 11, so that the metering flow is only related to the opening degree of the metering valve 9. The fuel enters the high-pressure shutoff valve 5 through the metering valve 9, when the metering flow is small, the high-pressure shutoff valve 5 is closed, the fuel system is ensured to have enough high-pressure oil Ps, when the metering flow is increased, the high-pressure shutoff valve 5 is opened, and the pressure behind the high-pressure shutoff valve 5 is P22. The metering oil enters the fuel grading valve 6 after passing through the high-pressure shutoff valve 5, and is controlled by the fuel grading valve 6 to be supplied to the first group of nozzles and the second group of nozzles.

In a typical aircraft engine fuel system, the pressure conditions of the metering fuel line are as follows: ps > P1> P2> P22;

the pressure conditions of the servo fuel oil circuit are as follows: ps > Pc > Pb, and Pc-Pb ═ constant.

As shown in fig. 2, the present disclosure provides an aircraft engine fuel system, in some embodiments, comprising: a high pressure shut-off shutter 5, an over-rotation solenoid valve 12 and an over-rotation execution shutter 13.

The high-pressure shutoff valve 5 has an on state and an off state, and is configured to control the on-off state of supplying fuel to the combustion chamber; the over-rotation solenoid valve 12 has an on state and an off state.

The overtravel execution valve 13 includes a first bushing 131 and a first piston 132, the first piston 132 is movably disposed in the first bushing 131, and at least a first cavity Q1, a third cavity Q3 and a fourth cavity Q4 are formed between the first piston and the first bushing 131, and the first bushing 131 is provided with a first oil port O1, a third oil port O3, a fourth oil port O4 and a fifth oil port O5; the fifth port O5 is communicated with the fourth chamber Q4 and is configured to selectively introduce the fuel oil at the first pressure value Ps, the fourth port O4 is communicated with the third chamber Q3 and the control chamber of the high pressure shutoff valve 5, and the third port O3 introduces the fuel oil at the second pressure value Pb, and the first pressure value Ps is greater than the second pressure value Pb.

As shown in fig. 4, in the over-rotation triggering state, the over-rotation solenoid valve 12 is switched to the on state to enable the fuel oil in the first cavity Q1 to enter the second pressure value Pb, the fuel oil in the first pressure value Ps is introduced into the fourth cavity Q4, the first piston 132 moves to the first limit position towards the first cavity Q1 under the action of the pressure difference between the first cavity Q1 and the fourth cavity Q4, which are located at the two ends, and the fourth oil port O4 is communicated with the third oil port O3 through the third cavity Q3, so that the fuel oil in the second pressure value Pb is introduced to the control cavity to enable the high-pressure shutoff valve 5 to be in the off state, and a passage for supplying the fuel oil to the combustion chamber is cut off; as shown in fig. 5, in the over-rotation locking state, the over-rotation solenoid valve 12 is switched to the off state, and the first piston 132 is kept at the same position by the pressure difference between the first chamber Q1 and the fourth chamber Q4, so that the high-pressure shut-off shutter 5 is kept at the off state.

The aircraft engine fuel system of the embodiment has an over-running protection function, after the rotating speed of the aircraft engine exceeds the preset rotating speed, an over-running instruction is triggered, the fuel system can cut off fuel oil supplied to a combustion chamber through the high-pressure cut-off valve 5, the oil cutting action is rapidly completed to stop the engine, and the over-running protection function can be mutually independent from a fuel oil control function.

In addition, in the embodiment, the over-rotation executing valve is connected in series in the high-pressure shutoff valve control cavity, and after the over-rotation instruction is triggered, the pressure of the high-pressure shutoff valve control cavity can be switched from high-pressure to oil return pressure. After the power failure of the over-rotation solenoid valve 12, the first piston 132 can still be kept unchanged by the pressure difference between the first chamber Q1 (with the second pressure value Pb) and the fourth chamber Q4 (with the first pressure value Ps) of the high-pressure shut-off valve 5, so that the high-pressure shut-off valve 5 is kept in a shut-off state before the metering valve 9 returns to the initial position, and the fuel system is in a fuel cut-off state.

The overtravel execution valve with the hydraulic locking function can avoid oscillation caused by pressure fluctuation in a large flow state, improve the reliability of the overtravel oil cutting function, maintain the pressure of a fuel system and ensure the normal servo action of the fuel system; and the structure form is simple, the weight is light, the volume weight of the accessory shell can be reduced, and the thrust-weight ratio of the engine is improved.

In some embodiments, the aircraft engine fuel system further comprises: a low-pressure pump 1 and a high-pressure pump 2 configured to supply oil to the combustion chamber; the first pressure value Ps corresponds to the outlet pressure of the high-pressure pump 2, and the second pressure value Pb corresponds to the outlet pressure of the low-pressure pump 1. The embodiment can ensure that the first pressure value Ps is higher than the second pressure value Pb, so that after the over-rotation command is triggered, the over-rotation execution valve 13 keeps hydraulic locking under the action of the pressure difference between the first cavity Q1 and the fourth cavity Q4 at the two ends, and the reliability of over-rotation oil cutting is improved.

In some embodiments, as shown in fig. 2, a second chamber Q2 is further formed between the first piston 132 and the first bushing 131, the first chamber Q1, the second chamber Q2, the third chamber Q3 and the fourth chamber Q4 are sequentially arranged, the first chamber Q1 is a spring chamber, a first return spring 133 is arranged in the spring chamber, and a second oil port O2 is further arranged on the first bushing 131. The over-rotation solenoid valve 14 is configured to supply the fuel at the second pressure value Pb to the second chamber O2 through the second port O2 in the over-rotation triggering state, and to supply the fuel at the first pressure value Ps to the second chamber O2 through the second port O2 in the over-rotation locking state.

This embodiment enables fuel provided by the over-rotation solenoid valve 14 to enter the second chamber Q2 when the first piston 132 moves to a first extreme position, and enables fuel provided by the over-rotation solenoid valve 14 to enter the first chamber Q1 when the first piston 132 moves to a second extreme position opposite the first extreme position during normal operating conditions.

In some embodiments, as shown in fig. 2, the high pressure shut-off shutter 5 includes a control valve body 51 and an actuating valve body 52, the control valve body 51 includes a second bushing 511 and a second piston 512, the second piston 512 is movably provided in the second bushing 511 and divides a control chamber in the control valve body 51 into a first control chamber CQ1 and a second control chamber CQ2, the first control chamber CQ1 introduces fuel oil at a first pressure value Ps, and the first control chamber CQ1 communicates with a third chamber Q3 through a fourth oil port O4, and the second control chamber CQ2 has the first pressure value Ps.

Specifically, the second bushing 511 is provided with a first control oil port and a second control oil port, and the first control oil port is provided with the throttle valve 14, so that the fuel oil with the first pressure value Ps is introduced into the first control chamber CQ1, which can be used to control the operation speed of the third piston 522 in the action valve body 52 and prevent the action valve body 52 from acting too fast to cause a water hammer in the oil path; the second control port is communicated with the third chamber Q3 through a fourth port O4. To smooth the operation of second piston 512, second piston 512 is U-shaped, and a first control chamber CQ1 is formed between an outer bottom surface of the U-shaped and second bushing 511.

In the over-rotation triggering state, as shown in fig. 4, the first control chamber CQ1 introduces fuel at the second pressure value Pb through the third chamber Q3, and since the pressure of the first control chamber CQ1 is lower than that of the second control chamber CQ2, the second piston 512 moves to the left to the extreme position, so as to close the operating valve body 52.

This embodiment can control the high pressure shut-off valve 5 to be in the on state or the off state by the fuel passing from the over-rotation performing valve 13 into the first control chamber CQ1 of the high pressure shut-off valve 5, thereby reliably controlling the state of the high pressure shut-off valve 5 upon receiving the over-rotation instruction.

In some embodiments, as shown in fig. 2, the aircraft engine fuel system further includes a metering valve 9 and a fuel classification valve 6, the high-pressure shutoff valve 5 includes a control valve body 51 and an actuating valve body 52, the actuating valve body 52 includes a third bushing 521 and a third piston 522, the third piston 522 is movably disposed in the third bushing 521 and divides a cavity in the third bushing 521 into a working chamber WQ1 and a spring chamber WQ2, a second return spring 523 is disposed in the spring chamber WQ2, and the third bushing 521 is provided with a first working oil port WO1 connected to the metering valve 9 and a second working oil port WO2 connected to the fuel classification valve 6.

As shown in fig. 3, in a normal operation state, the first working port WO1 and the second working port WO2 are communicated to supply fuel to the combustion chamber; as shown in fig. 4, in the over-rotation triggering state, the third piston 522 is moved to separate the first and second working ports WO1 and WO2 by the control valve body 51 to shut off the operating valve body 52, thereby shutting off the fuel supplied to the combustion chamber.

Optionally, the third piston 522 has a U-shaped configuration with a working chamber WQ1 defined between an outer bottom surface of the U-shaped configuration and the third bushing 521.

Alternatively, the second piston 512 and the third piston 522 are connected by a connecting rod 524 in order for the control valve body 51 to control the actuator valve body 52. In order to improve the sealing performance, the connecting rod 524 can be sleeved with a sealing ring 513; or a sealing ring 513 is arranged between the second piston 512 and the second liner 511 to prevent the control oil from mixing with the metering fuel oil; alternatively, a seal 513 may be disposed between third piston 522 and third bushing 521.

Alternatively, a communication hole 5221 may be provided in the third piston 522 to equalize the fuel pressure experienced by the third piston 522.

The high-pressure shut-off shutter 5 in this embodiment can effect switching of the acting valve body 52 between the on state and the off state by the control valve body 51.

In some embodiments, as shown in fig. 2, the aircraft engine fuel system further includes a metering valve 9, the metering valve 9 includes a fourth bushing 91 and a fourth piston 92, the fourth piston 92 is movably disposed in the fourth bushing 91, and divides a cavity in the fourth bushing 91 into a fifth cavity Q5, a sixth cavity Q6, a seventh cavity Q7 and an eighth cavity Q8 in sequence, the fourth bushing 91 is provided with a sixth oil port O6, a seventh oil port O7, an eighth oil port O8, a ninth oil port O9, a tenth oil port O10 and an eleventh oil port O11, the sixth oil port O6 and the eleventh oil port O11 are respectively communicated with the fifth cavity Q5 and the eighth cavity Q8, and the fuel oil at the second pressure value Pb or the third pressure value Pc is selectively introduced into the fourth piston 92; the seventh chamber O7 is communicated with the fourth chamber Q4 through a ninth port O9 and a fifth port O5, and a throttle valve 12 is provided on a communicated passage, and the regulation pressure of the throttle valve 12 is a first pressure value Ps; the tenth port O10 is supplied with the fuel oil at the second pressure value Pb.

On this basis, in the initial reset state, the seventh port O7 and the eighth port O8 are separated to shut off the metering valve 9, and the fourth chamber Q4 is communicated with the tenth port O10 through the seventh chamber Q7 and has a second pressure value Pb; in the remaining state, the seventh port O7 and the eighth port O8 are communicated through the sixth chamber Q6 to turn on the metering valve 9, and the seventh chamber Q4 is cut off from being communicated with the tenth port O10 to make the fourth chamber Q4 have the first pressure value Ps.

This embodiment can meter the fuel supplied to the combustion chamber by the metering shutter 9, supply the control fuel to the fourth chamber Q4 of the over-rotation performing shutter 13, and switch the pressure in the fourth chamber Q4 between the first pressure value Ps and the second pressure value Pb. The fuel system can ensure that the fuel system can complete the oil cutting action when an over-rotation command is triggered at any position of the metering valve 9, and can ensure that the fuel system is in the oil cutting state before the metering valve 9 returns to the initial position after the over-rotation command is cancelled.

In the above described embodiment, the aircraft engine fuel system further comprises a metering shutter 9 connected upstream of the high pressure shut-off shutter 5 and a fuel staging valve 6 connected downstream of the high pressure shut-off shutter 5, the aircraft engine fuel system having a normal operating state, an over-rotation triggered state, an over-rotation locked state and an initial reset state, wherein:

in a normal working state, the over-rotation electromagnetic valve 12 is in a turn-off state, the metering valves 9 are all in a turn-on state, the first piston 132 is in a second limit position, and the high-pressure turn-off valve 5 is in a turn-on state;

in the over-rotation triggering state, the over-rotation electromagnetic valve 12 is in a connection state, the metering valves 9 are in a connection state, the first piston 132 is in a first limit position, and the high-pressure shutoff valve 5 is in a shutoff state;

in the over-rotation locking state, the over-rotation electromagnetic valve 12 is in a disconnected state, the metering valve 9 is in a connected state, the first piston 132 is in a first limit position, and the high-pressure shutoff valve 5 is in a disconnected state;

in the initial reset state, the over-rotation solenoid valve 12 and the metering valve 9 are both in the off state, the metering valve 9 is in the off state, the first piston 132 is in the first limit position, the high-pressure shut-off valve 5 is in the off state, the pressure of the fourth chamber Q4 is switched to the second pressure value Pb, and the first piston 132 is moved by the pressure difference to be restored to the normal working state.

The working principle of the aircraft engine fuel system shown in fig. 2 and the working state diagrams of fig. 3 to 6 will be described.

As shown in fig. 2, the electro-hydraulic servo valve of the metering shutter 9 switches between the third pressure value Pc and the second pressure value Pb of the constant pressure in the fifth chamber Q5 and the eighth chamber Q8 at both ends of the metering shutter 9 in accordance with the electric signal sent from the electronic controller, and moves up and down in the fourth bushing 91 in the fourth piston 92 of the metering shutter 9. The third piston 522 of the operation valve body 52 of the high pressure shutoff valve 5 performs two-position left and right operation in the third bushing 521, and in order to reduce the driving force required for the operation of the third piston 522, the third piston 522 is connected to the second piston 512 of the control valve body 51 by a connecting rod 524. The second control chamber CQ2 (rodless chamber) of the control valve body 51 has a first pressure value Ps, the pressure of the first control chamber CQ1 (rod chamber) is affected by the over-rotation solenoid valve 12 and the over-rotation execution valve 13, the internal pressure of the first control chamber CQ1 (rod chamber) is switched between the first pressure value Ps and a second pressure value Pb, when the pressure of the first control chamber CQ1 is the first pressure value Ps, the fuel system can work normally, when the pressure of the first control chamber CQ1 is the second pressure value Pb, the second piston 512 moves to the left end limit position under the action of the pressure difference between the first control chamber CQ1 and the second control chamber CQ2, so as to drive the third piston to move to the left end limit position, and the first working oil port WO1 and the second working oil port WO2 are used for realizing the oil cutting action.

When the over-rotation electromagnetic valve 12 is de-energized, the output pressure is Ps, and when the over-rotation electromagnetic valve 12 is energized, the output pressure is the first pressure value Ps. The first piston 132 is movable left and right in the first bushing 131, and the first piston 132 divides the cavity in the first bushing 131 into a first cavity Q1, a second cavity Q2, a third cavity Q3 and a fourth cavity Q4 in sequence from left to right.

The first cavity Q1 is communicated with a working oil port of the over-rotation solenoid valve 12, and when the over-rotation solenoid valve 12 is powered on or powered off, the pressure in the first cavity Q1 is switched between the first pressure value Ps and the second pressure value Pb.

The pressure in the second chamber Q2 is related to the position of the first piston 132, when the first piston 132 moves to the rightmost second limit position, the second chamber Q2 is communicated with the third port O3, and the internal pressure is the second pressure value Pb; when the first piston 132 moves to the leftmost first limit position, the second chamber Q2 communicates with the working port of the over-rotation solenoid valve 12, and switches between the first pressure value Ps and the second pressure value Pb according to the output of the working port of the over-rotation solenoid valve 12.

The third chamber Q3 is communicated with the first control chamber CQ1 of the control valve body 51 in the high pressure shutoff valve 5, the pressure of the third chamber Q3 is related to the position of the first piston 132, when the first piston 132 is at the rightmost second limit position, the pressure of the third chamber Q3 is communicated with the first pressure value Ps, when the first piston 132 is at the leftmost first limit position, the third chamber Q3 is communicated with the second pressure value Pb through the third oil port O3, and the pressure relief of the first control chamber CQ1 of the control valve body 51 is the second pressure value Pb.

The pressure of the fourth chamber Q4 is related to the position of the fourth piston 92 in the metering valve 9, when the metering valve 9 is located at the closed position, the pressure of the fourth chamber Q4 is connected to the second pressure value Pb, after the metering valve 9 is actuated, the oil path between the fourth chamber Q4 and the second pressure value Pb introduced from the seventh oil port O7 of the metering valve 9 is cut off, and at this time, the pressure of the fourth chamber Q4 is the first pressure value Ps.

The overrun actuator shutter 13 has four states: an initial reset state, as shown in fig. 6, in which the metering shutter 9 is in the fully closed position, the over-rotation solenoid valve 12 is de-energized, and the first piston 132 in the over-rotation performing shutter 13 is driven to the leftmost first limit position by the pressure difference between the first chamber Q1 and the fourth chamber Q4 and the first return spring 133; in a normal operating state, as shown in fig. 3, the metering shutter 9 is in the open position, the over-rotation solenoid valve 12 is de-energized, and the first piston 132 in the over-rotation actuating shutter 13 is kept in the rightmost second limit position under the action of the first return spring 133; an overrun execution state, as shown in fig. 4, in which the metering shutter 9 is in the open position, the overrun solenoid valve 12 is energized, and the first piston 132 in the overrun execution shutter 13 moves to the leftmost first limit position under the effect of the pressure difference; in the over-rotation locking state, as shown in fig. 5, the metering shutter 9 is in the open position, the over-rotation solenoid valve 12 is de-energized, and the first piston 132 in the over-rotation performing shutter 13 is held at the leftmost first limit position by the pressure difference between the first chamber Q1 and the fourth chamber Q4. The throttle valve 14 functions to maintain a large pressure difference with Pb when the Ps oil passage is connected to the Pb oil passage. The four states will be described in detail below.

FIG. 3 is a schematic diagram of the fuel system in a normal operating condition. At this time, the over-rotation solenoid valve 12 is in a shut-off state, and the metering valve 9 is opened. The pressures of the first chamber Q1 and the fourth chamber Q4 of the over-rotation executing valve 13 are both first pressure values Ps, under the action of the first return spring 133, the first piston 132 moves to the second limit position on the right side, the first control chamber CQ1 of the high-pressure shut-off valve 5 is the first pressure value Ps, the third piston 522 moves in the third bushing 521 under the action of the differential pressure of the first control chamber CQ1 and the second control chamber CQ2 in the metered fuel pressure P2, the second return spring 523 and the control valve body 51, and the metered fuel enters the fuel grade valve 6 through the high-pressure shut-off valve 5.

FIG. 4 is a schematic diagram of the fuel system in an over-run triggered state. At this time, the over-rotation solenoid valve 613 is in the on state, and the metering shutter 9 is opened. The pressure of the first chamber Q1 of the over-rotation executing valve 13 is the second pressure value Pb, the pressure of the fourth chamber Q4 is the first pressure value Ps, the first piston 132 moves leftwards against the resistance of the first return spring 133 under the action of the pressure difference between the two ends, the third chamber Q3 is communicated with the oil path of the second pressure value Pb introduced from the third oil port O3 in the moving process of the first piston 132, and the pressure relief of the first control chamber CQ1 of the high-pressure shutoff valve 5 is the second pressure value Pb. In the fuel system the first pressure value Ps is higher than the metered fuel pressure P2, so the third piston 522 is moved to the left by the second return spring 523 and the pressure difference to fully close, cutting off the fuel supply to the fuel staging valve 6.

FIG. 5 is a schematic diagram of the fuel system in an over-run locked state. At this time, the over-rotation solenoid valve 613 is de-energized, and the metering shutter 9 is opened. At this time, since the first piston 132 of the over-rotation performing shutter 13 moves to the leftmost first limit position, the first chamber Q1 becomes a dead space, the first piston 132 is held at the leftmost first limit position by the first pressure value Ps of the fourth chamber Q4, and is in a hydraulic locking state, and the pressure of the first control chamber CQ1 of the control valve body 51 of the high-pressure shut-off shutter 5 is still the second pressure value Pb. In the fuel system, the pressure of the first pressure value Ps is higher than the metered fuel pressure P2, so that the high-pressure shutoff valve 5 can be held in the closed position by the second return spring 523 and the pressure difference.

FIG. 6 is a schematic diagram of the fuel system in an initial reset state. At this time, the over-rotation electromagnetic valve 12 is de-energized, and the metering valve 9 is closed. When the metering valve 9 is closed, the fuel oil with the second pressure value Pb introduced from the tenth port O10 of the metering valve 9 is communicated with the fourth chamber Q4 of the over-rotation performing valve 13, at this time, in the state of fig. 6, the first piston 132 is gradually moved rightward under the action of the first return spring 133, when the piston moves to the rightmost second limit position, the third chamber Q3 of the over-rotation performing valve 13 is disconnected from the fuel oil with the second pressure value Pb introduced from the third port O3, and the pressure of the first control chamber CQ1 of the high-pressure shut-off valve 5 is restored to the first pressure value Ps, so as to be restored to the normal operating state.

An aircraft engine fuel system and an aircraft engine provided by the disclosure are described in detail above. The principles and embodiments of the present disclosure are explained herein using specific examples, which are set forth only to help understand the method and its core ideas of the present disclosure. It should be noted that, for those skilled in the art, it is possible to make several improvements and modifications to the present disclosure without departing from the principle of the present disclosure, and such improvements and modifications also fall within the scope of the claims of the present disclosure.

Claims

1. An aircraft engine fuel system comprising:

a high-pressure shutoff valve (5) having an on state and an off state, configured to control the on-off state of supplying fuel to the combustion chamber;

an over-rotation solenoid valve (12) having an on state and an off state; and

the overtravel execution valve (13) comprises a first lining (131) and a first piston (132), the first piston (132) is movably arranged in the first lining (131), a first cavity (Q1), a third cavity (Q3) and a fourth cavity (Q4) are at least formed between the first piston and the first lining (131), and a first oil port (O1), a third oil port (O3), a fourth oil port (O4) and a fifth oil port (O5) are formed in the first lining (131); the fifth oil port (O5) is communicated with the fourth cavity (Q4) and is configured to selectively introduce fuel oil with a first pressure value (Ps), the fourth oil port (O4) is communicated with the third cavity (Q3) and the control cavity of the high-pressure shutoff valve (5), the third oil port (O3) introduces fuel oil with a second pressure value (Pb), and the first pressure value (Ps) is larger than the second pressure value (Pb);

under the over-rotation triggering state, the over-rotation electromagnetic valve (12) is switched to the connection state to enable the fuel oil with a second pressure value (Pb) to enter the first cavity (Q1), the fuel oil with a first pressure value (Ps) is introduced into the fourth cavity (Q4), the first piston (132) moves to a first limit position towards the first cavity (Q1) under the action of pressure difference between the first cavity (Q1) and the fourth cavity (Q4) at two ends, and the fourth oil port (O4) is communicated with the third oil port (O3) through the third cavity (Q3) to enable the fuel oil with the second pressure value (Pb) to be led to the control cavity to enable the high-pressure shutoff valve (5) to be in the shutoff state; and in the over-rotation locking state, the over-rotation solenoid valve (12) is switched to the off state, and the first piston (132) keeps the position under the action of the pressure difference between the first cavity (Q1) and the fourth cavity (Q4).

2. The aircraft engine fuel system of claim 1, further comprising:

a low-pressure pump (1) and a high-pressure pump (2) configured to supply oil to the combustion chamber;

wherein the first pressure value (Ps) coincides with an outlet pressure of the high-pressure pump (2), and the second pressure value (Pb) coincides with an outlet pressure of the low-pressure pump (1).

3. The aircraft engine fuel system according to claim 1, wherein a second cavity (Q2) is further formed between the first piston (132) and the first bushing (131), the first cavity (Q1), the second cavity (Q2), the third cavity (Q3) and the fourth cavity (Q4) are sequentially arranged, and a second oil port (O2) is further formed in the first bushing (131);

wherein the over-rotation solenoid valve (14) is configured to supply the fuel of the second pressure value (Pb) to the second chamber (O2) through the second port (O2) in an over-rotation triggering state, and to supply the fuel of the first pressure value (Ps) to the second chamber (O2) through the second port (O2) in an over-rotation locking state.

4. The aircraft engine fuel system according to claim 1, wherein the high pressure shut-off shutter (5) comprises a control valve body (51) and an actuating valve body (52), the control valve body (51) comprises a second bushing (511) and a second piston (512), the second piston (512) is movably arranged in the second bushing (511) and divides a control cavity in the control valve body into a first control cavity (CQ1) and a second control cavity (CQ2), the first control cavity (CQ1) introduces fuel at a first pressure value (Ps) and is communicated with the third cavity (Q3) through the fourth oil port (O4), and the second control cavity (CQ2) has the first pressure value (Ps);

wherein, in an over-rotation triggering state, the first control chamber (CQ1) introduces fuel oil with a second pressure value (Pb) through the third chamber (Q3) to move the second piston (512) to close the acting valve body (52).

5. The aircraft engine fuel system according to claim 1, further comprising a metering valve (9) and a fuel classification valve (6), wherein the high-pressure shutoff valve (5) comprises a control valve body (51) and an action valve body (52), the action valve body (52) comprises a third bushing (521) and a third piston (522), the third piston (522) is movably arranged in the third bushing (521) and divides a cavity in the third bushing (521) into a working cavity (WQ1) and a spring cavity (WQ2), and a first working oil port (WO1) connected with the metering valve (9) and a second working oil port (WO2) connected with the fuel classification valve (6) are arranged on the third bushing (521);

wherein, under the normal working state, the first working oil port (WO1) and the second working oil port (WO2) are communicated; in an over-rotation triggering state, the third piston (522) moves to separate the first working oil port (WO1) and the second working oil port (WO2) under the action of the control valve body (51) so as to close the action valve body (52).

6. The aircraft engine fuel system according to claim 1, further comprising a metering shutter (9) comprising a fourth bushing (91) and a fourth piston (92), the fourth piston (92) is movably disposed within the fourth bushing (91), and the cavity in the fourth bush (91) is divided into a fifth cavity (Q5), a sixth cavity (Q6), a seventh cavity (Q7) and an eighth cavity (Q8) in turn, a sixth oil port (O6), a seventh oil port (O7), an eighth oil port (O8), a ninth oil port (O9), a tenth oil port (O10) and an eleventh oil port (O11) are arranged on the fourth bush (91), the sixth oil port (O6) and the eleventh oil port (O11) are respectively communicated with the fifth cavity (Q5) and the eighth cavity (Q8), and selectively introducing fuel at a second pressure value (Pb) or a third pressure value (Pc) to move the fourth piston (92); the seventh cavity (O7) is communicated with the fourth cavity (Q4) through a ninth oil port (O9) and a fifth oil port (O5), a throttle valve (12) is arranged on a communicated passage, and the adjusting pressure of the throttle valve (12) is a first pressure value (Ps); the tenth oil port (O10) is filled with the fuel oil with a second pressure value (Pb).

7. The aircraft engine fuel system according to claim 6, wherein in an initial reset state, the seventh port (O7) and the eighth port (O8) are separated to shut off the metering shutter (9), and the fourth chamber (Q4) is communicated with the tenth port (O10) through a seventh chamber (Q7) and has a second pressure value (Pb); in other states, the seventh port (O7) and the eighth port (O8) are communicated through a sixth chamber (Q6) to connect the metering valve (9), and the seventh chamber (Q4) is cut off from being communicated with a tenth port (O10) to enable the fourth chamber (Q4) to have a first pressure value (Ps).

8. The aircraft engine fuel system according to claim 1, further comprising a metering shutter (9) connected upstream of the high pressure shut-off shutter (5) and a fuel staging valve (6) connected downstream of the high pressure shut-off shutter (5), the aircraft engine fuel system having a normal operating state, an over-rotation triggered state, an over-rotation locked state and an initial reset state, wherein:

under the normal working state, the over-rotation electromagnetic valve (12) is in a turn-off state, the metering valves (9) are in a turn-on state, the first piston (132) is in a second limit position, and the high-pressure turn-off valve (5) is in a turn-on state;

under the over-rotation triggering state, the over-rotation electromagnetic valve (12) is in a connection state, the metering valves (9) are in connection states, the first piston (132) is in a first limit position, and the high-pressure shutoff valve (5) is in a shutoff state;

under the over-rotation locking state, the over-rotation electromagnetic valve (12) is in a disconnected state, the metering valves (9) are in a connected state, the first piston (132) is in a first limit position, and the high-pressure shutoff valve (5) is in a disconnected state;

under the initial reset state, over-rotation solenoid valve (12) with measurement valve (9) all are in the off-state, first piston (132) are in first extreme position, high pressure is shut off valve (5) and is in the off-state, the pressure of fourth chamber (Q4) is switched into second pressure value (Pb), makes first piston (132) move and resume normal operating condition through pressure differential.

9. An aircraft engine comprising an aircraft engine fuel system according to any one of claims 1 to 8.