阅读说明：本技术 一种低温环境的流体计量活门 (Fluid metering valve in low-temperature environment ) 是由 刘雪娇 毛碧波 杨天硕 杨惠英 于 2019-08-02 设计创作，主要内容包括：本发明涉及一种低温环境的流体计量活门,所述计量活门包括计量油针和衬套,衬套开有通油孔,所述油针穿设在所述通油孔中；所述油针与通油孔之间为配合间隙,所述间隙用于通过计量的燃油；所述油针的外径与通油孔内径为间隙配合,间隙量小于0.05mm；在油针外壁面上形成有斜平面或曲面,所述斜平面或曲面与通油孔之间形成圆缺孔配合,且随着油针的轴向滑动,所述圆缺孔的流通面积会改变,从而影响流体的流量。本发明使得间隙之间的孔有效间隙更大,实际流动中更接近小孔节流,受到粘度的影响更小,具有更好的低温流量特性。(The invention relates to a fluid metering valve in a low-temperature environment, which comprises a metering oil needle and a bushing, wherein the bushing is provided with an oil through hole, and the oil needle penetrates through the oil through hole; a fit clearance is formed between the oil needle and the oil through hole, and the clearance is used for passing the metered fuel oil; the outer diameter of the oil needle is in clearance fit with the inner diameter of the oil through hole, and the clearance is less than 0.05 mm; an inclined plane or a curved surface is formed on the outer wall surface of the oil needle, a circular hole is formed between the inclined plane or the curved surface and the oil through hole to be matched, and the flow area of the circular hole can be changed along with the axial sliding of the oil needle, so that the flow of fluid is influenced. The invention ensures that the effective gap of the hole between the gaps is larger, the actual flow is closer to the small hole for throttling, the influence of viscosity is smaller, and the invention has better low-temperature flow characteristic.)

1. a fluid metering valve in low-temperature environment is characterized in that: the metering valve comprises a metering oil needle and a bushing, the bushing is provided with an oil through hole, and the oil needle penetrates through the oil through hole; a fit clearance is formed between the oil needle and the oil through hole, and the clearance is used for passing the metered fuel oil;

The outer diameter of the oil needle is in clearance fit with the inner diameter of the oil through hole, and the clearance is less than 0.05 mm;

An inclined plane or a curved surface is formed on the outer wall surface of the oil needle, a circular hole is formed between the inclined plane or the curved surface and the oil through hole to be matched, and the flow area of the circular hole can be changed along with the axial sliding of the oil needle, so that the flow of fluid is influenced.

2. A cryogenic environment fluid metering shutter as claimed in claim 1, wherein: the kinematic viscosity of the fluid is in the range of 0.53mm²/s～5.84mm²/s。

3. A cryogenic environment fluid metering shutter as claimed in claim 1, wherein: the fluid is fuel oil of an aircraft engine.

4. A cryogenic environment fluid metering shutter as claimed in claim 1, wherein: the inclined plane and the central axis of the oil needle form an angle of 5-15 degrees.

5. A fluid metering valve comprises a metering oil needle and a bushing, wherein the bushing is provided with an oil through hole, and the oil needle penetrates through the oil through hole; a fit clearance is formed between the oil needle and the oil through hole, and the clearance is used for passing the metered fuel oil;

The outer conical surface of the oil needle is in annular clearance fit with the oil through hole, and the oil needle axially slides to form annular clearance fit with adjustable flow area;

An inclined plane or a curved surface is formed on the outer conical surface of the oil needle, a circular gap hole is formed between the inclined plane or the curved surface and the oil through hole and matched with each other, an overflowing gap is formed between the circular gap hole and the annular gap, and the overflowing gap can be changed along with the axial sliding of the oil needle, so that the flow of fluid is influenced.

6. A fluid metering shutter as claimed in claim 1 wherein: the kinematic viscosity of the fluid is in the range of 0.53mm²/s～5.84mm²/s。

7. a fluid metering shutter as claimed in claim 1 wherein: the fluid is fuel oil of an aircraft engine.

8. A fluid metering shutter as claimed in claim 1 wherein: the inclined plane and the central axis of the oil needle form an angle of 5-15 degrees.

Technical Field

The invention relates to the field of low-temperature fluid control, in particular to a fluid metering valve in a low-temperature environment, which is suitable for a fuel metering unit of an aircraft engine fuel pump regulator, is used for realizing accurate metering of fuel and simultaneously ensures the accuracy of fuel metering under the low-temperature environment condition.

background

The fuel pump regulator is an important component of an aircraft engine control system, wherein a fuel metering valve realizes accurate metering of fuel flow by changing the opening of the valve. In general, a structural form of 'measuring oil needle-pore plate' is adopted in a fuel oil measuring valve, the profile of a measuring oil needle is a conical surface, the profile has high measuring precision under the normal temperature condition, but under the condition of small opening and low temperature environment, the gap of an annular flow window formed by the oil needle and the pore plate is small, the flow section flows in a gap, and the measured flow rate has larger deviation than the normal temperature due to the increase of the kinematic viscosity of the fuel oil under the low temperature condition, the flow rate of the fuel oil is reduced and the measured flow rate has larger deviation than the normal temperature. Through experimental verification, the measured flow under the condition of low temperature under the same opening degree of the measuring valve is reduced by about 60 percent compared with the measured flow under the condition of normal temperature.

The metering shutter generally comprises: the oil metering device comprises a metering oil needle, a metering valve bushing and a guide device. The metering valve bush is in interference fit with the inner hole of the guide device 3, the metering oil needle is assembled in the metering valve bush and the guide device, and the metering oil needle is guaranteed to normally move in the guide device by controlling the requirement of the gap.

for medium and small power class engines, flow differences of this magnitude may cause engine cold start performance deviations. Therefore, it is necessary to improve the accuracy of fuel metering under low temperature conditions and to improve the low temperature flow characteristics.

disclosure of Invention

The purpose of the invention is as follows: through the measurement oil needle of research and development novel profile, improve the low temperature flow characteristic of measurement valve, improve low temperature environment measurement accuracy nature.

Technical scheme

Providing a fluid metering valve in a low-temperature environment, wherein the metering valve comprises a metering oil needle and a bushing, the bushing is provided with an oil through hole, and the oil needle is arranged in the oil through hole in a penetrating manner; a fit clearance is formed between the oil needle and the oil through hole, and the clearance is used for passing the metered fuel oil;

The outer diameter of the oil needle is in clearance fit with the inner diameter of the oil through hole, and the clearance is less than 0.05 mm;

an inclined plane or a curved surface is formed on the outer wall surface of the oil needle, a circular hole is formed between the inclined plane or the curved surface and the oil through hole to be matched, and the flow area of the circular hole can be changed along with the axial sliding of the oil needle, so that the flow of fluid is influenced.

Further, in the above-mentioned case,the kinematic viscosity of the fluid is in the range of 0.53mm²/s～5.84mm²/s。

further, the fluid is fuel oil of an aircraft engine.

Furthermore, the inclined plane and the central axis of the oil needle form an angle of 5-15 degrees.

Providing a fluid metering valve, wherein the metering valve comprises a metering oil needle and a bushing, the bushing is provided with an oil through hole, and the oil needle penetrates through the oil through hole; a fit clearance is formed between the oil needle and the oil through hole, and the clearance is used for passing the metered fuel oil;

the outer conical surface of the oil needle is in annular clearance fit with the oil through hole, and the oil needle axially slides to form annular clearance fit with adjustable flow area;

An inclined plane or a curved surface is formed on the outer conical surface of the oil needle, a circular gap hole is formed between the inclined plane or the curved surface and the oil through hole and matched with each other, an overflowing gap is formed between the circular gap hole and the annular gap, and the overflowing gap can be changed along with the axial sliding of the oil needle, so that the flow of fluid is influenced.

Further, the kinematic viscosity of the fluid is in the range of 0.53mm²/s～5.84mm²/s。

Further, the fluid is fuel oil of an aircraft engine.

furthermore, the inclined plane and the central axis of the oil needle form an angle of 5-15 degrees.

Technical effects

The common advantages are that:

1) Compared with an independent conical surface metering oil needle, the inclined plane type or the outer conical surface + inclined plane type metering oil needle has the advantages that the windows of the inclined plane or the outer conical surface + inclined plane are round holes, the effective gap of the holes is larger, the actual flow is closer to the orifice throttling, the influence of viscosity is smaller, and the low-temperature flow characteristic is better;

2) The metering valve has high metering precision, and the displacement and the flow of the metering valve have higher linearity, so that a numerical control system can accurately control the flow of fuel oil conveniently;

3) The hydraulic characteristic test of the metering valve assembly is independently carried out according to the hydraulic characteristic, and the tested metering valve has the characteristic of high displacement-flow characteristic consistency, so that the interchangeability of the fuel pump regulator is improved.

The inclined plane or curved surface type metering oil needle has the advantages that: the inclined plane or curved surface type metering oil needle has simple processing procedures, the molded surface is processed by high-precision linear cutting, the molded surface consistency is high, and the flow characteristic consistency is high;

the outer conical surface + inclined plane type oil needle has the advantages that: the metering valve overflow area is composed of an annular gap between an outer conical surface and the oil through hole and a circular gap between an inclined surface and the oil through hole, so that the low-temperature flow performance can be guaranteed, and meanwhile, in the stroke of the oil needle, the fit gap between the oil needle and the oil through hole is increased along with the increase of the opening degree, and the metering valve overflow area has higher pollution resistance.

Drawings

fig. 1a is a schematic view of an inclined or curved surface, external cone + inclined plane metering shutter invention.

Fig. 1b is a schematic view of an inclined plane or curved surface.

fig. 1c is a schematic view of the outer cone + the inclined plane.

wherein: 1-metering oil needle, 2-metering valve bush, 3-guiding device, 4-inclined plane or curved surface type surface, 5-outer conical surface + inclined surface type surface.

Detailed Description

referring to fig. 1a and 1b, a fluid metering valve in a low-temperature environment is provided, wherein the metering valve comprises a metering oil needle and a bush, the bush is provided with an oil through hole, and the oil needle penetrates through the oil through hole; a fit clearance is formed between the oil needle and the oil through hole, and the clearance is used for passing the metered fuel oil;

The outer diameter of the oil needle is in clearance fit with the inner diameter of the oil through hole, and the clearance is less than 0.05 mm;

An inclined plane or a curved surface is formed on the outer wall surface of the oil needle, a circular hole is formed between the inclined plane or the curved surface and the oil through hole to be matched, and the flow area of the circular hole can be changed along with the axial sliding of the oil needle, so that the flow of fluid is influenced.

The kinematic viscosity of the fluid is in the range of 0.7mm²/s。

The fluid is fuel oil of an aircraft engine.

The inclined plane and the central axis of the oil needle form an angle of 10 degrees.

Referring to fig. 1c, a fluid metering valve is provided, the metering valve comprises a metering oil needle and a bush, the bush is provided with an oil through hole, and the oil needle is arranged in the oil through hole in a penetrating manner; a fit clearance is formed between the oil needle and the oil through hole, and the clearance is used for passing the metered fuel oil;

The outer conical surface of the oil needle is in annular clearance fit with the oil through hole, and the oil needle axially slides to form annular clearance fit with adjustable flow area;

An inclined plane or a curved surface is formed on the outer conical surface of the oil needle, a circular gap hole is formed between the inclined plane or the curved surface and the oil through hole and matched with each other, an overflowing gap is formed between the circular gap hole and the annular gap, and the overflowing gap can be changed along with the axial sliding of the oil needle, so that the flow of fluid is influenced.

The kinematic viscosity of the fluid is in the range of 0.6mm²/s。

the fluid is fuel oil of an aircraft engine.

The inclined plane and the central axis of the oil needle form an angle of 10 degrees.

for example, the selected fluid can be aviation kerosene, the viscosity of the fuel oil is 1.48mm2/s, the sectional iterative design of the measuring oil needle profile is carried out, the linear relation of displacement and flow is realized on the basis of an inclined plane, and the inclined plane and the central axis of the oil needle form an angle of 5-12 degrees. The overflow profile of the inclined plane type metering oil needle is a round hole. The flow area of the structure is closer to the orifice throttling when the flow is small, and the kinematic viscosity influence on the fuel oil when the fuel oil flows under the low-temperature condition is smaller, so that the low-temperature small-flow characteristic is improved. The experiment proves that the flow of the metering valve is reduced by about 13 percent compared with the normal temperature in the low-temperature environment, and the flow is obviously improved by 60 percent compared with the conical surface metering valve.