阅读说明：本技术 一种步进电机驱动的高可靠燃油计量装置 (High-reliability fuel metering device driven by stepping motor ) 是由 李伟 胡春艳 韩博 王锐 高猛 徐纲 于 2019-09-23 设计创作，主要内容包括：本发明公开了一种步进电机驱动的高可靠燃油计量装置,用于燃气轮机、航空发动机燃油泵调节器中的燃油计量,具体为采用步进电机驱动旋转式计量活门动作,改变计量活门周向形孔的遮蔽面积,实现经过计量活门燃油流量的计量。该装置结构新颖、简单、容易加工和装配、控制简单灵活、可靠性高。所述计量活门采用周向形孔设计、径向进出油设计和平衡回油路设计,可以消除活门阀芯的轴向力,有效减小阀芯的运动阻力矩,降低活门卡滞风险,提高计量活门的动态响应特性和可靠性；该方案利用步进电机的保持转矩锁住计量活门阀芯的角相位置,能够抵抗机械振动、活门液动力、电机电流波动等外界扰动对活门控制的干扰,大幅提高燃油计量装置的鲁棒性和可靠性。(The invention discloses a high-reliability fuel metering device driven by a stepping motor, which is used for metering fuel in fuel pump regulators of gas turbines and aero-engines. The device has the advantages of novel and simple structure, easy processing and assembly, simple and flexible control and high reliability. The metering valve adopts a circumferential hole design, a radial oil inlet and outlet design and a balanced oil return path design, so that the axial force of a valve core of the valve can be eliminated, the movement resistance moment of the valve core is effectively reduced, the valve clamping risk is reduced, and the dynamic response characteristic and the reliability of the metering valve are improved; the scheme utilizes the holding torque of the stepping motor to lock the angular phase position of the valve core of the metering valve, can resist the interference of external disturbances such as mechanical vibration, valve hydrodynamic force, motor current fluctuation and the like on the valve control, and greatly improves the robustness and reliability of the fuel metering device.)

1. a high-reliability fuel metering device driven by a stepping motor comprises the stepping motor and a metering valve component, wherein the metering valve component comprises a metering valve shell, a metering valve limiter, a metering valve core, a metering valve sleeve, a metering valve movable sealing cover and a metering valve rear end cover, the metering valve shell is integrally a hollow cylindrical component with two open ends, the metering valve core and the metering valve sleeve are arranged in the metering valve shell, at least one step surface is formed on the inner wall of the front end opening of the metering valve shell, the metering valve movable sealing cover is fixedly arranged on the step surface, the metering valve rear end cover is fixedly arranged on the rear end opening of the metering valve shell, and the high-reliability fuel metering device is characterized in that,

the metering valve core comprises a main body part, a first-stage shaft shoulder and a second-stage shaft shoulder, wherein the first-stage shaft shoulder and the second-stage shaft shoulder are positioned at the front end of the main body part;

the metering valve sleeve is coaxially inserted and fixed on the hollow cylindrical inner wall of the metering valve shell, the metering valve sleeve is coaxially sleeved on the outer surface of the main body part of the metering valve core, and the metering valve core can rotate relative to the metering valve sleeve; wherein the content of the first and second substances,

the metering valve comprises a metering valve shell, a metering valve body and a control valve, wherein an oil inlet annular oil cavity and an oil outlet annular oil cavity are arranged on the hollow cylindrical inner wall of the metering valve shell, the oil inlet annular oil cavity is located at a first axial position, the oil outlet annular oil cavity is located at a second axial position, and a shell oil inlet oil way communicated with the oil inlet annular oil cavity and a shell oil outlet oil way communicated with the oil outlet annular oil cavity are arranged on the metering valve shell;

A first valve sleeve annular groove located at the first axial position is formed in the outer wall of the metering valve sleeve, and a valve sleeve oil inlet hole extending along the circumferential direction is formed in the bottom of the first valve sleeve annular groove; a second valve sleeve annular groove located at the second axial position is formed in the inner wall of the metering valve sleeve, and a plurality of valve sleeve oil outlet holes uniformly distributed along the circumferential direction are formed in the bottom of the second valve sleeve annular groove;

A valve core hollow cavity is arranged in the main body part of the valve core of the metering valve, and a plug is arranged at the rear end of the valve core hollow cavity for plugging; a valve core fan-shaped window which is located at the first axial position and extends along the circumferential direction is arranged on the main body part of the valve core of the metering valve, a valve core annular groove which is located at the second axial position is arranged on the outer wall of the main body part of the valve core of the metering valve, a plurality of valve core oil outlet holes which are uniformly distributed along the circumferential direction are arranged at the bottom of the valve core annular groove, and the valve core fan-shaped window and each valve core oil outlet hole are communicated with the valve core hollow cavity;

The valve sleeve oil inlet hole is matched with the valve core fan-shaped window, a fuel oil metering through hole is formed in the part where the valve sleeve oil inlet hole and the valve core fan-shaped window are not overlapped, and the flow area of the fuel oil metering through hole is changed along with the rotation of the valve core of the metering valve;

high-pressure fuel oil enters the oil inlet annular oil cavity from an inlet P of the shell oil inlet oil way in the radial direction, passes through a fuel oil metering through hole formed by the valve sleeve oil inlet hole and the valve core fan-shaped window and then flows into the valve core hollow cavity in the radial direction, and the metered fuel oil enters the oil outlet annular oil cavity through the valve core oil outlet holes and the valve sleeve oil outlet holes in sequence and then flows out from an outlet T of the shell oil outlet oil way in the radial direction.

2. The stepping motor driven high-reliability fuel oil metering device according to the previous claim, wherein the stepping motor is a single-coil single-redundancy stepping motor, a double-coil double-redundancy stepping motor or a stepping motor with a deceleration output.

3. The high-reliability fuel metering device driven by the stepping motor as claimed in the preceding claim, wherein the metering valve limiter comprises a limiter sleeve portion, a limiter upper arm, a limiter lower arm, a metering valve minimum opening limit adjusting nail and a metering valve maximum opening limit adjusting nail, wherein a central hole of the limiter sleeve portion is fixedly sleeved on a second-stage shaft shoulder of the metering valve core; the upper arm and the lower arm of the limiter are circumferentially arranged on the outer peripheral wall of the sleeve part of the limiter at a certain angle; the outer edge of the axial outer end face of the movable sealing cover of the metering valve extends outwards along the axial direction to form an arc-shaped convex block, the arc-shaped convex block is integrally positioned in the front end opening of the metering valve shell, an upper limit nail mounting hole and a lower limit nail mounting hole are formed in the outer wall of the front end opening of the metering valve shell, a through hole is respectively formed in the upper end and the lower end of the arc-shaped convex block, the minimum opening limit adjusting nail of the metering valve sequentially penetrates through the upper limit nail mounting hole, the rear length of the upper end through hole of the arc-shaped convex block is adjustably mounted on the metering valve shell, the maximum opening limit adjusting nail of the metering valve sequentially penetrates through the lower limit nail mounting hole, the rear length of the lower end through hole of the arc-shaped convex block is adjustably mounted on the metering valve shell, and the minimum opening limit adjusting nail of the metering, The extending length of the maximum opening limit adjusting nail of the metering valve is used for adjusting the movement limit positions of the upper arm and the lower arm of the limiter, and then the whole rotary movement interval of the valve core of the metering valve is limited.

4. The stepping motor driven high reliability fuel oil metering device according to the previous claim, wherein the upper arm and the lower arm of the stopper are integrally formed with the stopper sleeve portion, and a long hole extending along the radial direction of the stopper sleeve portion is respectively formed at the center of the upper arm and the lower arm of the stopper, each long hole extends to communicate with the central hole of the stopper sleeve portion, a fastening screw is respectively arranged in each long hole, and the stopper sleeve portion is fastened and arranged on the second stage shoulder of the valve core of the metering valve by means of the two fastening screws.

5. the stepping motor driven high-reliability fuel oil metering device as claimed in the above claim, wherein the dynamic sealing part between the first stage shaft shoulder of the valve core of the metering valve and the central hole of the dynamic sealing cover of the metering valve is a dynamic sealing gurley ring, and an O-ring seal is arranged between the dynamic sealing cover of the metering valve and the step surface on the inner wall of the front end opening of the housing of the metering valve for static sealing.

6. The stepping motor driven high-reliability fuel oil metering device as claimed in the preceding claim, characterized in that the end of the plug at the rear end of the valve core of the metering valve is rotatably supported in the supporting hole at the center of the rear end cover of the metering valve, and a dynamic sealing GREEN ring is arranged between the end of the plug and the supporting hole; the rear end cover of the metering valve is fixedly arranged on the rear end opening of the metering valve shell through a fastener, and an O-shaped sealing ring is arranged between the rear end cover and the metering valve shell for static sealing.

7. the stepper motor driven high reliability fuel metering device of the previous claims, wherein the length of the metering valve sleeve in the axial direction is substantially the same as the length of the main body portion of the metering valve spool.

8. the stepper motor driven high reliability fuel metering device as claimed in the above claims, wherein a plurality of radial O-rings are axially disposed between the metering valve housing and the metering valve housing for sealing.

9. The stepper motor driven high reliability fuel metering device as claimed in the above claims, wherein the axial and angular phase position of the metering valve housing is limited by a housing radial positioning pin inserted into the metering valve housing and the metering valve housing.

10. The stepping motor driven high reliability fuel oil metering device according to the previous claim, wherein the spaces between the front and rear ends of the valve sleeve of the metering valve and the housing of the metering valve are respectively formed as a front end oil leakage chamber and a rear end oil leakage chamber, and the fuel oil leaked between the front and rear ends of the valve core of the metering valve and the valve sleeve of the metering valve respectively enters the front end oil leakage chamber and the rear end oil leakage chamber; the wall surface of the metering valve shell is provided with a front-end oil return channel and a rear-end oil return channel which extend axially and are symmetrically arranged, the wall surface of the metering valve shell is further provided with a metering valve oil return opening extending radially, the inlets of the front-end oil return channel and the rear-end oil return channel are communicated with the front-end oil leakage cavity and the rear-end oil leakage cavity respectively, the outlets of the front-end oil return channel and the rear-end oil return channel are communicated with the inlet of the metering valve oil return opening, and the outlet of the metering valve oil return opening is communicated with the outside.

11. the stepper motor driven highly reliable fuel metering device as in the previous claims, wherein the inlet P of the housing inlet oil path is in communication with the outlet of the fuel pump, high pressure fuel enters the inlet annular oil chamber from the housing inlet oil path in a radial direction, and the outlet B of the metering valve return port is in communication with the inlet of the fuel pump.

12. The stepping motor driven highly reliable fuel metering device as set forth in the preceding claim, wherein the projection of the valve sleeve oil inlet hole in the circumferential direction is a wedge-shaped hole as a whole, and the axial width of one circumferential end of the wedge-shaped hole is the smallest and the axial width of the other circumferential end of the wedge-shaped hole is the largest.

Technical Field

The invention relates to a high-reliability fuel metering device driven by a stepping motor, which is used for metering fuel in fuel pump regulators of gas turbines and aero-engines.

Background

The fuel metering device is a core element in a fuel control system and a fuel pump regulator of a gas turbine and an aero-engine, the engine realizes the accurate metering and control of the fuel quantity of each oil way such as a combustion chamber of the engine through the fuel metering device, and the stability, the dynamic characteristic and the reliability of the fuel control of the whole engine are directly determined by the advantages and disadvantages of the metering precision, the resolution, the consistency, the steady state and the dynamic characteristic, the reliability and other characteristics of the fuel metering device.

In order to meet the high requirements of steady state and dynamic characteristics of engine fuel control, the position control precision of a fuel metering device of the engine fuel metering device usually reaches a micron level, and a control time constant reaches a millisecond level, the traditional design scheme mostly adopts an electro-hydraulic servo valve, a torque motor, a direct current brushless motor or a quick valve to servo-drive a slide valve type metering valve to act, and the metering of fuel flow is realized by feeding back the position of a valve core of the metering valve through an LVDT or RVDT to form small closed loop control. The scheme has a complex system structure and extremely high requirements on the precision of processing and assembly, and inevitably uses a small-hole structure sensitive element in order to meet the dynamic characteristic requirements of the system, so that the scheme has extremely high requirements on the cleanliness of the system, the sliding valve has large motion resistance and serious abrasion, and the reliability is not easy to guarantee; on the other hand, due to the introduction of small closed-loop control, the robustness of the system is not high, the capability of resisting external environment disturbances such as mechanical vibration, valve hydrodynamics, current fluctuation, electromagnetic interference and the like is poor, and the stability of the system is not easy to guarantee. Therefore, a better fuel metering scheme is urgently needed to be provided, and the robustness and the reliability of a fuel metering system are improved while the metering precision and the dynamic characteristic are ensured.

disclosure of Invention

Aiming at the defects and shortcomings of the prior art, the invention provides a high-reliability fuel metering device driven by a stepping motor, aiming at simplifying the complex structure of the fuel metering device, eliminating a small hole structure, reducing the resistance and the abrasion of a moving element, improving the capability of a fuel metering system for resisting external environment disturbances such as mechanical vibration, valve hydrodynamic force, current fluctuation, electromagnetic interference and the like, and further improving the robustness and the reliability of the fuel metering system.

The technical scheme adopted by the invention for solving the technical problem is as follows:

a high-reliability fuel metering device driven by a stepping motor comprises the stepping motor and a metering valve component, wherein the metering valve component comprises a metering valve shell, a metering valve limiter, a metering valve core, a metering valve sleeve, a metering valve movable sealing cover and a metering valve rear end cover, the metering valve shell is integrally a hollow cylindrical component with two open ends, the metering valve core and the metering valve sleeve are arranged in the metering valve shell, at least one step surface is formed on the inner wall of the front end opening of the metering valve shell, the metering valve movable sealing cover is fixedly arranged on the step surface, the metering valve rear end cover is fixedly arranged on the rear end opening of the metering valve shell, and the high-reliability fuel metering device is characterized in that,

The metering valve core comprises a main body part, a first-stage shaft shoulder and a second-stage shaft shoulder, wherein the first-stage shaft shoulder and the second-stage shaft shoulder are positioned at the front end of the main body part;

the metering valve sleeve is coaxially inserted and fixed on the hollow cylindrical inner wall of the metering valve shell, the metering valve sleeve is coaxially sleeved on the outer surface of the main body part of the metering valve core, and the metering valve core can rotate relative to the metering valve sleeve; wherein the content of the first and second substances,

The metering valve comprises a metering valve shell, a metering valve body and a control valve, wherein an oil inlet annular oil cavity and an oil outlet annular oil cavity are arranged on the hollow cylindrical inner wall of the metering valve shell, the oil inlet annular oil cavity is located at a first axial position, the oil outlet annular oil cavity is located at a second axial position, and a shell oil inlet oil way communicated with the oil inlet annular oil cavity and a shell oil outlet oil way communicated with the oil outlet annular oil cavity are arranged on the metering valve shell;

a first valve sleeve annular groove located at the first axial position is formed in the outer wall of the metering valve sleeve, and a valve sleeve oil inlet hole extending along the circumferential direction is formed in the bottom of the first valve sleeve annular groove; a second valve sleeve annular groove located at the second axial position is formed in the inner wall of the metering valve sleeve, and a plurality of valve sleeve oil outlet holes uniformly distributed along the circumferential direction are formed in the bottom of the second valve sleeve annular groove;

a valve core hollow cavity is arranged in the main body part of the valve core of the metering valve, and a plug is arranged at the rear end of the valve core hollow cavity for plugging; a valve core fan-shaped window which is located at the first axial position and extends along the circumferential direction is arranged on the main body part of the valve core of the metering valve, a valve core annular groove which is located at the second axial position is arranged on the outer wall of the main body part of the valve core of the metering valve, a plurality of valve core oil outlet holes which are uniformly distributed along the circumferential direction are arranged at the bottom of the valve core annular groove, and the valve core fan-shaped window and each valve core oil outlet hole are communicated with the valve core hollow cavity;

The valve sleeve oil inlet hole is matched with the valve core fan-shaped window, a fuel oil metering through hole is formed in the part where the valve sleeve oil inlet hole and the valve core fan-shaped window are not overlapped, and the flow area of the fuel oil metering through hole is changed along with the rotation of the valve core of the metering valve;

high-pressure fuel oil enters the oil inlet annular oil cavity from an inlet P of the shell oil inlet oil way in the radial direction, passes through a fuel oil metering through hole formed by the valve sleeve oil inlet hole and the valve core fan-shaped window and then flows into the valve core hollow cavity in the radial direction, and the metered fuel oil enters the oil outlet annular oil cavity through the valve core oil outlet holes and the valve sleeve oil outlet holes in sequence and then flows out from an outlet T of the shell oil outlet oil way in the radial direction.

preferably, the stepping motor is a single-coil single-redundancy stepping motor, a double-coil double-redundancy stepping motor or a stepping motor with deceleration output. According to the requirements of resolution and reliability index of the fuel metering device, the precision and the resolution of fuel metering can be further improved by using a stepping motor with speed reduction output or step pitch subdivision control of the stepping motor, and the reliability of an electric control system can be further improved by using a double-coil double-redundancy stepping motor.

Preferably, the metering valve limiter comprises a limiter sleeve part, a limiter upper arm, a limiter lower arm, a metering valve minimum opening degree limiting adjusting nail and a metering valve maximum opening degree limiting adjusting nail, wherein a central hole of the limiter sleeve part is fixedly sleeved on a second-stage shaft shoulder of the metering valve core; the upper arm and the lower arm of the limiter are circumferentially arranged on the outer peripheral wall of the sleeve part of the limiter at a certain angle; the outer edge of the axial outer end face of the movable sealing cover of the metering valve extends outwards along the axial direction to form an arc-shaped convex block, the arc-shaped convex block is integrally positioned in the front end opening of the metering valve shell, an upper limit nail mounting hole and a lower limit nail mounting hole are formed in the outer wall of the front end opening of the metering valve shell, a through hole is respectively formed in the upper end and the lower end of the arc-shaped convex block, the minimum opening limit adjusting nail of the metering valve sequentially penetrates through the upper limit nail mounting hole, the rear length of the upper end through hole of the arc-shaped convex block is adjustably mounted on the metering valve shell, the maximum opening limit adjusting nail of the metering valve sequentially penetrates through the lower limit nail mounting hole, the rear length of the lower end through hole of the arc-shaped convex block is adjustably mounted on the metering valve shell, and the minimum opening limit adjusting nail of the metering, The extending length of the maximum opening limit adjusting nail of the metering valve is used for adjusting the movement limit positions of the upper arm and the lower arm of the limiter, and then the whole rotary movement interval of the valve core of the metering valve is limited. Because the stepping motor directly drives the valve core of the metering valve and the metering valve limiter to rotate together, the initial angular phase position and the maximum rotation angle of the metering valve limiter and the valve core of the metering valve are limited by the minimum opening degree limiting adjusting nail and the maximum opening degree limiting adjusting nail of the metering valve which are symmetrically arranged, and then the minimum opening degree and the maximum opening degree of the metering valve are limited.

Furthermore, the upper limiter arm, the lower limiter arm and the sleeve limiter part are integrally formed, long holes extending along the radial direction of the sleeve limiter part are respectively arranged at the centers of the upper limiter arm and the lower limiter arm, each long hole extends to be communicated with the central hole of the sleeve limiter part, a fastening screw is respectively arranged in each long hole, and the sleeve limiter part is fastened and arranged on the second-stage shaft shoulder of the valve core of the metering valve by means of the two fastening screws.

In the high-reliability fuel metering device driven by the stepping motor, the stepping motor is directly connected with the metering valve core, the stepping motor directly drives the metering valve core to rotate together with the upper arm and the lower arm of the metering valve limiter, and the initial angular phase position and the maximum rotation angle of the upper arm and the lower arm of the metering valve limiter are limited by the symmetrically arranged minimum opening degree limiting adjusting nail and the maximum opening degree limiting adjusting nail of the metering valve.

Preferably, a dynamic sealing part between a first-stage shaft shoulder of the valve core of the metering valve and a central hole of the dynamic sealing cover of the metering valve is a dynamic sealing GREEN ring, and an O-shaped sealing ring is arranged between the dynamic sealing cover of the metering valve and a step surface on the inner wall of the front end opening of the shell of the metering valve for static sealing.

preferably, the tail end of the plug at the rear end of the valve core of the metering valve is rotatably supported in a support hole at the center of the rear end cover of the metering valve, and a dynamic sealing GREEN ring is arranged between the tail end of the plug and the support hole; the rear end cover of the metering valve is fixedly arranged on the rear end opening of the metering valve shell through a fastener, and an O-shaped sealing ring is arranged between the rear end cover and the metering valve shell for static sealing.

Preferably, the length of the metering valve sleeve in the axial direction is substantially the same as the length of the main body part of the metering valve core.

Preferably, a plurality of radial O-shaped sealing rings are axially arranged between the metering valve housing and the metering valve sleeve for sealing.

preferably, the axial and angular phase position of the metering valve sleeve is limited by a sleeve radial positioning pin inserted into the metering valve housing and the metering valve sleeve. The metering valve sleeve is designed in a plug-in mode, and the axial position and the angular position of the metering valve sleeve are limited by radial positioning pins inserted into the metering valve shell and the metering valve sleeve.

in the high-reliability fuel metering device driven by the stepping motor, the valve sleeve oil inlet holes are formed along the circumferential direction of the valve sleeve of the metering valve, the valve core fan-shaped window is formed along the circumferential direction of the valve core of the metering valve, the oil outlet holes are formed along the valve sleeve of the metering valve and the valve core of the metering valve in the radial direction, and the end part of the valve core of the metering valve is blocked by adopting a plug. The metering valve shell is provided with an oil inlet oil path and an oil inlet annular oil cavity and is communicated with the oil inlet of the metering valve sleeve. The metering valve shell is provided with an oil outlet oil way and an oil outlet annular oil cavity and is communicated with an oil outlet of the metering valve sleeve. The high-pressure fuel entering the oil inlet path flows into the valve core of the metering valve along the radial direction through the hole on the valve sleeve of the metering valve and the fan-shaped window on the valve core of the metering valve, and the metered fuel flows out from the oil outlet of the metering valve along the radial direction through the valve core of the metering valve and the oil outlet window on the valve sleeve of the metering valve.

preferably, the space between the front end and the rear end of the metering valve sleeve and the metering valve shell is respectively formed into a front-end oil leakage cavity and a rear-end oil leakage cavity, and the fuel oil leaked between the front end and the rear end of the metering valve core and the metering valve sleeve respectively enters the front-end oil leakage cavity and the rear-end oil leakage cavity; the wall surface of the metering valve shell is provided with a front-end oil return channel and a rear-end oil return channel which extend axially and are symmetrically arranged, the wall surface of the metering valve shell is further provided with a metering valve oil return opening extending radially, the inlets of the front-end oil return channel and the rear-end oil return channel are communicated with the front-end oil leakage cavity and the rear-end oil leakage cavity respectively, the outlets of the front-end oil return channel and the rear-end oil return channel are communicated with the inlet of the metering valve oil return opening, and the outlet of the metering valve oil return opening is communicated with the outside. The front-end oil return channel and the rear-end oil return channel form a balanced oil return path and are respectively communicated with the front-end oil leakage cavity and the rear-end oil leakage cavity, so that the axial force generated by the pressure difference between two ends of the valve core of the metering valve is eliminated.

Furthermore, an inlet P of the shell oil inlet oil way is communicated with an outlet of a fuel pump, high-pressure fuel oil enters the oil inlet annular oil cavity from the shell oil inlet oil way along the radial direction, and an outlet B of the metering valve oil return port is communicated with the inlet of the fuel pump.

in the high-reliability fuel metering device driven by the stepping motor, the metering valve assembly adopts a balanced oil return path design, symmetrical oil paths are formed on the metering valve shell, oil chambers on two sides of the metering valve core are communicated with the metering valve oil return path, so that axial force generated by pressure difference on two sides of the metering valve core is eliminated, the metering valve dynamic sealing assembly and the metering valve end cover assembly are arranged on two sides of the metering valve core, and dynamic sealing is performed through a Gray ring arranged on the metering valve dynamic sealing assembly.

preferably, the valve sleeve oil inlet hole is a wedge-shaped hole in the circumferential projection overall, the axial width of one circumferential end of the wedge-shaped hole is the minimum, and the axial width of the other circumferential end of the wedge-shaped hole is the maximum. According to the high-reliability fuel metering device driven by the stepping motor, the rotation angle of the valve core of the metering valve is controlled through the forward and backward steps of the stepping motor, so that the through flow area formed by the valve sleeve-shaped hole of the metering valve and the fan-shaped window of the valve core of the metering valve is changed, the metering of the fuel flow is realized, and the control of the opening area of the hole of the metering valve is not influenced by the current and voltage changes of the motor. The device can utilize the holding torque of the stepping motor to lock the angular phase position of the valve core of the metering valve, and can resist the interference of external disturbance such as mechanical vibration, valve hydrodynamic force, motor current fluctuation, electromagnetic interference and the like on valve control.

The invention relates to a high-reliability fuel metering device driven by a stepping motor, which has the working principle that:

The fuel metering device is matched with a fuel pump and an isobaric difference valve assembly in a fuel pump regulator to jointly complete metering of fuel flow of an engine. The fuel pump provides a high-pressure fuel oil source, the constant pressure difference valve assembly ensures that the fuel oil pressure difference between the inlet and the outlet of the metering valve is approximately a constant value, and the flow rate of the throttling hole can be known according to a flow formula:

In the formula:

Q: by metering the flow of the valve;

C_d: measuring the flow coefficient of a valve hole;

A: measuring the opening area of a valve hole;

Δ P: when the flow rate is Q, the pressure difference of the inlet and the outlet of the valve-shaped hole is measured;

ρ: the density of the fuel;

according to the formula analysis, for a set of specific fuel metering device and use working conditions, the fuel flow of the metering valve and the opening area of the hole of the metering valve are in one-to-one correspondence, so that the rotating angle of the valve core of the metering valve is controlled by the steps of forward movement and backward movement of the stepping motor, the opening area of the hole of the metering valve is changed, and the fuel flow metering function of the metering valve can be realized.

Compared with the prior art, the invention has the advantages that:

1) The invention cancels a small hole sensing element and a metering valve position sensor, simplifies the complex structure of the fuel metering device, reduces the risk of the jamming of the metering valve, greatly simplifies the design of a fuel control system, reduces the fault probability of the system and improves the reliability because a position feedback small closed loop of the metering valve is cancelled.

2) The rotary metering valve structure is adopted to replace a slide valve type metering valve, the motion damping and the clamping risk of the valve core can be reduced, meanwhile, the design of a balanced oil return path is adopted, the axial force generated by the pressure difference on two sides of the valve core is eliminated, the motion damping of the valve core is further reduced, the structure is flexible, and the reliability is high.

3) The invention locks the angular phase position of the valve core of the metering valve by using the holding torque of the stepping motor, and can resist the interference of external disturbance such as mechanical vibration, valve hydrodynamic force, motor current fluctuation, electromagnetic interference and the like on valve control.

4) The invention utilizes the steps of forward movement and backward movement of the stepping motor to control the rotation angle of the valve core of the metering valve, the control parameters are not influenced by the current and voltage changes of the motor, the control precision requirements on the current and voltage of the electric control system are reduced, and the robustness and reliability of the system are greatly improved.

Drawings

FIG. 1 is a front view cross-sectional structural schematic of the present invention;

FIG. 2 is a cross-sectional view of a metering valve stop according to the present invention;

FIG. 3 is a schematic three-dimensional assembly of the internal structure of the metering shutter of the present invention;

FIG. 4 is a three-dimensional schematic view of the metering valve sleeve configuration of the present invention;

FIG. 5 is a three-dimensional schematic view of the metering valve cartridge structure of the present invention;

FIG. 6 is a cross-sectional view of a metering valve bore of the present invention;

In the figure:

1-a stepping motor, 2-a metering valve shell, 3-a metering valve stopper, 4-a metering valve dynamic sealing cover, 5-a metering valve core, 6-a metering valve sleeve, 7-a valve sleeve radial positioning pin, 8-a plug, 9-a metering valve rear end cover, 21-a shell oil inlet oil way, 22-an oil inlet annular oil cavity, 23-a shell oil outlet oil way, 24-an oil outlet annular oil cavity, 25-a rear end oil leakage cavity, 26-a front end oil leakage cavity, 27-a rear end oil return channel, 28-a front end oil return channel, 29-a metering valve oil return opening, 30-a stopper sleeve, 31-a metering valve minimum opening degree limiting adjusting nail, 32-a metering valve maximum opening degree limiting adjusting nail, 33-a fastening screw and 34-a stopper, 35-a lower arm of a limiter, 40-a circular arc-shaped convex block, 41-O-shaped sealing rings, 42-a Glare ring, 51-a valve core oil inlet window, 52-a valve core oil outlet hole, 61-O-shaped sealing rings, 62-a valve sleeve oil inlet hole, 63-a valve sleeve oil outlet hole, 91-a Glare ring, 92-O-shaped sealing rings and 93-an end cover fixing screw.

Detailed Description

in order to make the technical scheme, the implementation mode and the advantages of the invention more clear and detailed, the invention is further described in detail by combining the schematic drawings and listing specific examples.

Fig. 1 is a schematic front view and sectional mechanism diagram of a high-reliability fuel metering device driven by a stepping motor, which comprises a stepping motor 1 and a metering valve assembly. The metering valve assembly comprises a metering valve shell 2, a metering valve limiter 3, a metering valve core 5, a metering valve sleeve 6, a metering valve dynamic sealing cover 4 and a metering valve rear end cover 9. The metering valve shell 2 is integrally a hollow cylindrical part with two open ends, the metering valve core 5 and the metering valve sleeve 6 are arranged in the metering valve shell 2, at least one step surface is formed on the inner wall of the front end opening of the metering valve shell 2, the metering valve movable sealing cover 4 is fixedly arranged on the step surface, and the metering valve rear end cover 9 is fixedly arranged on the rear end opening of the metering valve shell 2. The metering valve core 5 comprises a main body part, a first-stage shaft shoulder and a second-stage shaft shoulder, wherein the first-stage shaft shoulder is positioned at the center hole of the metering valve movable sealing cover 4, a movable sealing part is arranged between the first-stage shaft shoulder and the second-stage shaft shoulder, the second-stage shaft shoulder is positioned on the outer side of the first-stage shaft shoulder, the metering valve limiter 3 is arranged on the second-stage shaft shoulder, the front end of the second-stage shaft shoulder is in transmission connection with the stepping motor 1, and the metering valve limiter 3 is used for limiting the rotating motion interval of the metering valve core 5.

The metering valve sleeve 6 is coaxially inserted and fixed on the hollow cylindrical inner wall of the metering valve shell 2, the metering valve sleeve 6 is coaxially sleeved on the outer surface of the main body part of the metering valve core 5, and the metering valve core 5 can rotate relative to the metering valve sleeve 6; the metering valve shell 2 is provided with a shell oil inlet oil way 21 communicated with the oil inlet annular oil cavity 22 and a shell oil outlet oil way 23 communicated with the oil outlet annular oil cavity 24; a first valve sleeve annular groove located at a first axial position is formed in the outer wall of the metering valve sleeve 6, and a valve sleeve oil inlet hole 62 extending along the circumferential direction is formed in the bottom of the first valve sleeve annular groove; a second valve sleeve annular groove located at a second axial position is formed in the inner wall of the metering valve sleeve 6, and a plurality of valve sleeve oil outlet holes 63 uniformly arranged along the circumferential direction are formed in the bottom of the second valve sleeve annular groove; a valve core hollow cavity is arranged in the main body part of the valve core 5 of the metering valve, and the tail end of the valve core hollow cavity is provided with a plug 8 for plugging; a valve core fan-shaped window 51 which is located at a first axial position and extends along the circumferential direction is arranged on the main body part of the valve core 5 of the metering valve, a valve core annular groove which is located at a second axial position is arranged on the outer wall of the main body part of the valve core 5 of the metering valve, a plurality of valve core oil outlet holes 52 which are uniformly distributed along the circumferential direction are arranged at the bottom of the valve core annular groove, and the valve core fan-shaped window 51 and each valve core oil outlet hole 52 are communicated with a valve core hollow cavity; the valve sleeve oil inlet hole 62 is matched with the valve core fan-shaped window 51, a fuel oil metering through hole is formed in the part where the valve sleeve oil inlet hole and the valve core fan-shaped window 51 are not overlapped, and the flow area of the fuel oil metering through hole is changed along with the rotation of the valve core 5 of the metering valve; the high-pressure fuel enters the oil inlet annular oil cavity 22 from the inlet P of the shell oil inlet channel 21 along the radial direction, passes through the fuel metering through hole formed by the valve sleeve oil inlet hole 62 and the valve core fan-shaped window 51 and then flows into the valve core hollow cavity along the radial direction, and the metered fuel enters the oil outlet annular oil cavity 24 through the valve core oil outlet holes 52 and the valve sleeve oil outlet holes 63 in sequence and then flows out from the outlet T of the shell oil outlet channel 23 along the radial direction.

the stepping motor 1 is directly connected with the metering valve assembly, and the stepping motor 1 is a single-coil single-redundancy stepping motor, a double-coil double-redundancy stepping motor or a stepping motor with speed reduction output. According to the requirements of resolution and reliability index of the fuel metering device, the precision and the resolution of fuel metering can be further improved by using a stepping motor with speed reduction output or step pitch subdivision control of the stepping motor, and the reliability of an electric control system can be further improved by using a double-coil double-redundancy stepping motor.

with reference to fig. 1 to 3, the metering valve stopper 3 includes a stopper sleeve portion 30, a stopper upper arm 34, a stopper lower arm 35, a metering valve minimum opening degree limiting adjustment nail 31, and a metering valve maximum opening degree limiting adjustment nail 32, wherein a central hole of the stopper sleeve portion 30 is fixedly sleeved on a second stage shaft shoulder of the metering valve spool 5; the stopper upper arm 34 and the stopper lower arm 35 are circumferentially arranged on the outer peripheral wall of the stopper sleeve portion 30 at an angle; the outer edge of the axial outer end face of the movable sealing cover 4 of the metering valve extends outwards along the axial direction to form a circular arc-shaped convex block 41, the circular arc-shaped convex block 41 is integrally positioned in the front end opening of the metering valve shell 2, an upper limit nail mounting hole and a lower limit nail mounting hole are arranged on the outer wall of the front end opening of the metering valve shell 2, the upper end and the lower end of the circular arc-shaped convex block 41 are respectively provided with a through hole, a metering valve minimum opening limit adjusting nail 31 sequentially passes through the upper limit nail mounting hole, the rear length of the upper end through hole of the circular arc-shaped convex block 41 is adjustably mounted on the metering valve shell 2, a metering valve maximum opening limit adjusting nail 32 sequentially passes through the lower limit nail mounting hole, the rear length of the lower end through hole of the circular arc-shaped convex block 41 is adjustably mounted on the metering valve shell 2, and the extending lengths of the metering valve, and adjusting the movement limit positions of the upper limiter arm 34 and the lower limiter arm 35, and then limiting the rotary movement interval of the whole metering valve core 5. Because the stepping motor 1 directly drives the valve core 5 of the metering valve and the valve stopper 3 of the metering valve to rotate together, the initial angular phase position and the maximum rotation angle of the valve stopper 3 of the metering valve and the valve core 5 of the metering valve are limited by the minimum opening degree limiting adjusting nail 31 and the maximum opening degree limiting adjusting nail 32 of the metering valve which are symmetrically arranged, and the minimum opening degree and the maximum opening degree of the metering valve are further limited.

The upper limiter arm 34, the lower limiter arm 35 and the limiter sleeve portion 30 are integrally formed, a long hole extending along the radial direction of the limiter sleeve portion 30 is formed in the center of each of the upper limiter arm 34 and the lower limiter arm 35, each long hole extends to be communicated with the central hole of the limiter sleeve portion 30, a fastening screw 33 is arranged in each long hole, and the limiter sleeve portion 30 is fastened and arranged on the second-stage shaft shoulder of the metering valve spool 5 through the two fastening screws 33.

Fig. 2 is a sectional view of the stopper, showing the working principle of the stopper, wherein a metering valve minimum opening degree limiting adjusting nail 31 and a metering valve maximum opening degree limiting adjusting nail 32 are connected with a metering valve shell 2 through threads, penetrate through a semicircular lug 40 on a metering valve movable sealing cover 4, and adjust the movement limit positions of a stopper upper arm 34 and a stopper lower arm 35 by adjusting the extension lengths of the metering valve minimum opening degree limiting nail 31 and the metering valve maximum opening degree limiting adjusting nail 32, so as to limit the movement interval of the whole valve rotating element.

As shown in fig. 1, the length of the metering valve sleeve 6 in the axial direction is substantially the same as the main body portion of the metering valve spool 5. The metering valve sleeve 6 is designed in a plug-in manner, and the axial and angular phase positions of the metering valve sleeve 6 are limited by a valve sleeve radial positioning pin 7 inserted into the metering valve shell 2 and the metering valve sleeve 6. The space between the metering valve housing 2 and the metering valve sleeve 6 is sealed by a radial O-ring seal 61.

Fig. 3 is a three-dimensional assembly schematic diagram of the internal structure of the metering valve, and fig. 4 and 5 are three-dimensional schematic diagrams of the structures of a valve sleeve 6 and a valve core 5 of the metering valve respectively. The valve sleeve 6 of the metering valve is circumferentially provided with a valve sleeve oil inlet hole 62, the valve core 5 of the metering valve is circumferentially provided with a valve core fan-shaped window 51, the valve sleeve 6 and the valve core 5 of the metering valve are radially provided with a valve sleeve oil outlet 63 and a valve core oil outlet 52, and the end part of the valve core 5 of the metering valve is plugged by a plug 8 with threads. The metering valve shell 2 is provided with a shell oil inlet oil path 21 and an oil inlet annular oil chamber 22 which are communicated with the valve sleeve oil inlet hole 62. The metering valve shell 2 is communicated with the valve sleeve oil outlet hole 63 by opening the shell oil outlet oil path 23 and the oil outlet annular oil cavity 24. High-pressure fuel oil from the fuel pump enters the metering valve assembly from the port P of the shell oil inlet channel 21, flows into the interior of the metering valve core 5 along the radial direction through the valve sleeve oil inlet hole 62 and the valve core fan-shaped window 51, and flows out from the outlet port T of the shell oil outlet channel 23 along the radial direction through the metering valve core 5, the valve core oil outlet hole 52 of the metering valve sleeve 6 and the valve sleeve oil outlet hole 63 after metering.

The space between the front end and the rear end of the metering valve sleeve 6 and the metering valve shell 2 is respectively formed into a front-end oil leakage cavity 26 and a rear-end oil leakage cavity 25, and the fuel oil leaked between the front end and the rear end of the metering valve core 5 and the metering valve sleeve 6 respectively enters the front-end oil leakage cavity 26 and the rear-end oil leakage cavity 25; the wall surface of the metering valve shell 2 is provided with a front-end oil return channel 28 and a rear-end oil return channel 27 which extend axially and are symmetrically arranged, the wall surface of the metering valve shell 2 is also provided with a metering valve oil return channel 29 which extends radially, inlets of the front-end oil return channel 28 and the rear-end oil return channel 27 are respectively communicated with the front-end oil leakage cavity 26 and the rear-end oil leakage cavity 25, outlets of the front-end oil return channel 28 and the rear-end oil return channel 27 are communicated with an inlet of the metering valve oil return channel 29, and an outlet of the metering valve oil return channel 29 is communicated with the outside. The front end oil return passage 28 and the rear end oil return passage 27 are formed as a balanced oil return path, and are communicated with the front end oil leakage cavity 26 and the rear end oil leakage cavity 25 respectively, so that the axial force generated by the pressure difference between two ends of the valve core of the metering valve is eliminated. The inlet P of the housing oil inlet passage 21 is communicated with the outlet of the fuel pump, high-pressure fuel oil radially enters the oil inlet annular oil chamber 22 from the housing oil inlet passage 21, and the outlet B of the metering valve oil return port 29 is communicated with the inlet of the fuel pump.

in the high-reliability fuel metering device driven by the stepping motor, the metering valve assembly adopts a balanced oil return path design, a front end oil return channel 28 and a rear end oil return channel 27 are formed on the metering valve shell 2, and a front end oil leakage cavity 26 and a rear end oil leakage cavity 25 of a metering valve core are communicated with a metering valve oil return port 29, so that the axial force generated by the pressure difference on two sides of the metering valve core is eliminated.

In order to ensure the sealing performance, a dynamic sealing part between a first-stage shaft shoulder of the valve core 5 of the metering valve and a central hole of the dynamic sealing cover 4 of the metering valve is a dynamic sealing GREEN 42, and an O-shaped sealing ring 41 is arranged between the dynamic sealing cover 4 of the metering valve and a step surface on the inner wall of the front end opening of the shell 2 of the metering valve for static sealing. The tail end of a plug 8 at the rear end of a valve core 5 of the metering valve is rotatably supported in a support hole at the center of a rear end cover 9 of the metering valve, and a dynamic sealing GREEN 91 is arranged between the tail end and the support hole; the rear end cover 9 of the metering valve is fixedly arranged on the rear end opening of the metering valve shell 2 through a fastener, and an O-shaped sealing ring 92 is arranged between the rear end opening and the metering valve shell for static sealing. A plurality of radial O-shaped sealing rings 61 are arranged between the metering valve shell 2 and the metering valve sleeve 6 along the axial direction for sealing.

Fig. 6 is a cross-sectional view of the hole of the metering valve, the whole projection of the oil inlet hole 62 of the valve sleeve in the circumferential direction is a wedge-shaped hole, the axial width of one circumferential end of the wedge-shaped hole is the minimum, and the axial width of the other circumferential end of the wedge-shaped hole is the maximum. The valve core 5 of the metering valve is driven to rotate by the stepping motor 1, so that the flow area formed by the valve sleeve oil inlet hole 62 and the valve core oil inlet fan-shaped window 62 is changed, and the metering of the fuel flow is realized.

The above-described embodiments are merely preferred embodiments of the present invention, and it is obvious to those skilled in the art that various modifications and improvements can be made without departing from the technical solutions and principles of the present invention, and such modifications and improvements should be considered as the protection scope of the present invention.