CN108005826B

CN108005826B - Frequency conversion fuel sprayer

Info

Publication number: CN108005826B
Application number: CN201711162417.8A
Authority: CN
Inventors: 徐福印; 马传胜; 颜景龙; 徐广明; 徐新丽; 王其祥
Original assignee: Shandong Xinya Precision Machinery Manufacturing Co ltd
Current assignee: Shandong Xinya Precision Machinery Manufacturing Co.,Ltd.
Priority date: 2017-11-21
Filing date: 2017-11-21
Publication date: 2021-07-02
Anticipated expiration: 2037-11-21
Also published as: CN108005826A

Abstract

The invention discloses a variable-frequency oil spray nozzle, which belongs to the technical field of oil spray nozzles of automobile engines and comprises an oil spray nozzle shell, an oil spray head and a needle valve, wherein an oil spray cavity is formed in a gap between the oil spray nozzle shell and the needle valve; the inner surface of the oil spray hole is alternately distributed with convex ribs and inner grooves which extend along the axial direction of the oil spray hole along the circumference of the inner surface of the oil spray hole, and the convex ribs and the inner grooves both extend spirally along the axial direction of the oil spray hole; and the inner grooves are alternately distributed with lugs and grooves along the extension direction of the inner grooves. According to the invention, by optimizing the structure of the oil nozzle, the oil is ensured to be comprehensively subjected to effective acting force, the generation of turbulent flow is promoted, and the oil atomization effect is good; and the structure is simple, and the application is convenient.

Description

Frequency conversion fuel sprayer

Technical Field

The invention relates to the technical field of oil nozzles of automobile engines, in particular to a variable-frequency oil nozzle.

Background

With the development of economy, energy shortage and environmental pollution become worldwide problems, and how to further improve the efficiency of the internal combustion engine, save fuel and reduce emission becomes one of the important directions for the technical development of the internal combustion engine. The internal combustion engine technology of the present automobile mostly utilizes the characteristics of small viscosity and fast evaporation of gasoline, and the gasoline is mixed with air and atomized to form combustible mixed gas to be sprayed into a cylinder, so that the gasoline is easier to burn.

The oil spray hole of the oil spray nozzle for the vehicle at present mostly adopts a form that the inner diameter is unchanged and the friction coefficient of the inner surface is uniform. When the liquid flows on the surface of a uniform and consistent solid, laminar flow is easy to occur when the flow speed is small and turbulent flow is generated when the flow speed is large for gasoline with certain viscosity; under the condition that other conditions are not changed, the pipeline is small in diameter and easy to generate laminar flow, and the pipeline is large in diameter and easy to generate turbulent flow. In the laminar flow state, liquid in the pipe is divided into an adsorption layer and a free layer, the velocity flow field directions at different positions are all along the axial direction, and the velocity has no radial component. In the adsorption layer, from the inner wall to the adsorption layer, when the gasoline droplets flow along the small holes, the flow velocity of the gasoline droplets is gradually increased and changes in a gradient manner; in the free layer, the droplet flow rate is the same. In turbulent conditions, the velocity has a radial component. The process can be measured by Reynolds number, and the Reynolds number is completely dependent on the viscosity of the fluid, namely the ratio of inertia force to viscous force under the same flow rate, density and pore size. The reynolds number increases to such an extent that the droplet motion is converted from laminar flow to turbulent flow, which can also be said to be turbulent. The larger the Reynolds number is, the more irregular the internal movement is, the more likely collision is generated, and the more favorable the atomization of the oil liquid is. In fuel injection atomization, more severe turbulent motion is expected to be generated, but the increase in diameter can promote turbulent motion, but at the same time, increase in droplet size can reduce atomization effect, so that the automobile fuel injection system can realize turbulent motion by increasing flow speed under high pressure. Therefore, it is necessary to provide a simple fuel injection nozzle structure to improve the atomization effect of gasoline, reduce the high pressure requirement during gasoline atomization, and further reduce energy consumption.

Patent publication No. CN 105275698B discloses a variable frequency oil nozzle for an engine, which sets the inner surface of an oil nozzle hole at the front end of the oil nozzle into uniform wave shape, so that the inner diameter of the oil nozzle hole changes periodically along the axial direction; and the inner surface of the oil spray hole is alternately arranged into a large friction coefficient area and a small friction coefficient area along the axial direction, so that the friction coefficient of the inner surface of the oil spray hole periodically changes along the axial direction. The Reynolds number of the oil is improved through the change of the inner diameter and the change of the friction coefficient of the surface of the inner wall, so that the inner part of the oil moves violently, the molecular collision probability is increased, and the fuel atomization effect is improved. But it still has the disadvantages: because the inner surface of the oil spray hole is of a uniform wave-shaped structure, in the application process, oil in the center directly flows to the outlet end from the inlet end of the oil spray hole in a straight line mode, the peripheral oil flows along the surface of the hole with the periodically fluctuating inner diameter, the process of gathering to the middle and diffusing to the periphery is carried out alternately, all the peripheral oil is synchronously operated at a certain moment, and when the peripheral oil gathers to the middle, the impact effects of the oil on the two opposite sides of the center are mutually offset, so that the impact influence on the central oil is small. This results in insufficient atomization of the oil in the middle portion. And fluid when the nozzle orifice of above-mentioned structure flows, the interior concave part on hole surface has fluid to remain, and the injection of fluid is continuous in the jet time, in case interior concave part fluid remains more, the effect that the peripheral part of fluid that then flows through received weakens, has just strengthened the team of center fluid, and the not enough fluid of atomizing increases promptly, further reduces the nozzle tip function.

Disclosure of Invention

1. Technical problem to be solved

The technical problem to be solved by the invention is to provide a variable-frequency oil nozzle, which ensures that oil is relatively comprehensively subjected to effective acting force by optimizing the structure of the oil nozzle, promotes turbulent flow and has good oil atomization effect; and the structure is simple, and the application is convenient.

2. Technical scheme

In order to solve the problems, the invention adopts the following technical scheme:

a variable-frequency oil nozzle comprises an oil nozzle shell, an oil nozzle head and a needle valve, wherein an oil spraying cavity is formed in a gap between the oil nozzle shell and the needle valve, the oil nozzle head is arc-shaped and is positioned at one end of the oil nozzle shell, one end of the needle valve, which is positioned at the oil nozzle head, is conical, the conical end of the needle valve is tightly attached to the joint of the oil nozzle shell and the oil nozzle head, and a plurality of oil spraying holes are formed in the oil nozzle head; the inner surface of the oil spray hole is alternately distributed with convex ribs and inner grooves which extend along the axial direction of the oil spray hole along the circumference of the inner surface of the oil spray hole, and the convex ribs and the inner grooves both extend spirally along the axial direction of the oil spray hole; the inner grooves are alternately distributed with lugs and grooves along the extension direction of the inner grooves; the cross section of the convex rib is gradually narrowed from the surface connected with the inner wall of the oil injection hole to the opposite surface; the convex ribs are alternately distributed with second convex blocks and second concave grooves along the extending direction of the convex ribs, so that oil flowing through the convex ribs is subjected to the action force of fluctuation in the radial direction, and the generation of turbulent flow is promoted; the side wall of the inner groove and the side edge of the corresponding convex rib are positioned in the same plane, and the included angle between the plane and the bottom of the inner groove is an obtuse angle, so that the inner groove and the convex rib are alternately and tightly arranged, the inner surface of the oil spray hole is fully utilized, a structure for promoting the internal movement of oil is arranged as much as possible, and the oil can more comprehensively act on the oil flowing through the oil spray hole; the width of the inner groove is gradually widened from the groove bottom to the groove opening, so that oil can conveniently enter, more oil can be acted, and turbulent flow is promoted to occur.

As an improvement to the scheme, an included angle formed by a connecting line between two adjacent conversion points of spiral conversion points formed on the inner surface of the oil spray hole by the convex rib and the inner groove and the conversion points is an obtuse angle. So design, enlarged helical structure's pitch, the radian of protruding rib and inner groovy spiral is less, and the oil of being convenient for flows through the nozzle, and it is residual to reduce fluid, can reduce the fluid flow in-process its whole resistance that receives to reduce the loss, avoid the obvious reduction of velocity of flow, the guarantee takes place the turbulent flow.

As an improvement to the scheme, the outer surface of the part of the conical end of the needle valve, which is positioned in the oil spray head, is provided with threads. When the needle valve is opened, oil enters the oil spray head at a high speed, and the oil on the periphery of the outer surface of the needle valve flows along the threads, so that the possibility of generating turbulence is generated preliminarily; meanwhile, the oil liquid center generates a driving force to the periphery, and the oil liquid is promoted to enter the oil injection hole.

Furthermore, the oil spray hole is arranged at the part of the oil spray head surrounding the needle valve. If the oil injection hole is arranged on the oil injection head right in front of the needle valve, more oil can be injected from the oil injection hole, so that the uniformity of oil injection is not facilitated; just as above-mentioned, can produce the peripheral driving force by fluid center when the screw thread that needle valve toper end set up acts on, locate the position that locates the oil spout head around needle valve periphery with the nozzle opening, accord with fluid flow direction demand.

3. Advantageous effects

(1) The inner surface of the oil spray hole is alternately distributed with convex ribs and inner grooves which extend along the axial direction of the oil spray hole along the circumference of the inner surface of the oil spray hole, and the convex ribs and the inner grooves both extend spirally along the axial direction of the oil spray hole. After the oil enters the oil injection hole, at any time, one part of the peripheral oil moves towards the center under the action of the convex ribs to extrude the central oil, and the other part of the peripheral oil moves towards the periphery under the action of the inner groove, so that the central oil supplements the moving oil, and the peripheral oil and the central oil move alternately; protruding rib and the inner groovy of spiral extension make peripheral fluid along this helical structure spiral flow, and the peripheral fluid of spiral drives central fluid and takes place screw motion, and comparatively comprehensive messenger fluid produces radial motion all the time to make fluid take place the turbulent flow, its inside sub-motion is violent, has increased the clash probability of molecule, has promoted the fuel atomization effect.

(2) The invention is characterized in that the inner groove is alternately distributed with convex blocks and grooves along the extending direction of the inner groove. Peripheral fluid receives the radial effort of fluctuation change when following the spiral flow of inner groovy helical structure, promotes the radial fluctuation of peripheral fluid to the interactive motion of peripheral fluid of reinforcing and central fluid further promotes to take place the turbulent flow, promotes the fuel atomization effect.

(3) The structure of the invention is optimized only on the inner surface of the oil spray hole and the outer surface of the conical end of the needle valve, and the invention has simple structure and convenient application.

In conclusion, the oil nozzle structure is optimized, so that the oil is enabled to be comprehensively acted by effective acting force, the generation of turbulent flow is promoted, and the oil atomization effect is good; and the structure is simple, and the application is convenient.

Drawings

FIG. 1 is a schematic view of a fuel injector;

fig. 2 is a schematic structural view of the oil jet hole 6 as viewed from a port;

FIG. 3 is a schematic structural view of a section of the oil spray hole 6 after being expanded;

fig. 4 is a schematic view showing the structure of the spiral formed by the rib 11 and the inner groove 12 on the inner surface of the oil spout hole 6.

Reference numerals: 1-nozzle housing, 2-nozzle tip, 3-needle valve, 4-nozzle chamber, 5-thread, 6-nozzle hole, 11-rib, 12-inner groove, 13-bump, 14-groove, 15-bump two, 16-groove two.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples.

Examples

The variable-frequency oil nozzle shown in fig. 1 comprises an oil nozzle shell 1, an oil nozzle 2 and a needle valve 3, wherein an oil injection cavity 4 is formed in a gap between the oil nozzle shell 1 and the needle valve 3, the oil nozzle 2 is arc-shaped, the oil nozzle 2 is positioned at one end of the oil nozzle shell 1, one end, where the needle valve 3 is positioned, of the oil nozzle 2 is conical, the conical end of the needle valve 3 is tightly attached to the joint of the oil nozzle shell 1 and the oil nozzle 2, and a plurality of oil injection holes 6 are formed in the oil nozzle 2; as shown in fig. 2 and 3, the inner surface of the oil spray hole 6 is alternately provided with a rib 11 and an inner groove 12 along the circumference of the inner surface, the rib 11 and the inner groove 12 extend along the axial direction of the oil spray hole 6, and both the rib 11 and the inner groove 12 extend spirally along the axial direction of the oil spray hole 6; the inner grooves 12 are alternately distributed with convex blocks 13 and concave grooves 14 along the extending direction of the inner grooves 12.

In this embodiment, the cross section of the protruding rib 11 is gradually narrowed toward the opposite surface by connecting the inner wall of the oil spray hole 6, the side wall of the inner groove 12 and the side edge of the corresponding protruding rib 11 are located in the same plane, and the included angle between the plane and the bottom of the inner groove 12 is an obtuse angle. The inner grooves 12 and the convex ribs 11 are alternately and tightly arranged, the inner surface of the oil injection hole 6 is fully utilized, and a structure for promoting the internal movement of oil is arranged as much as possible, so that the oil can comprehensively act on the oil flowing through the oil injection hole 6; the width of the inner groove 12 is gradually widened from the groove bottom to the groove opening, so that oil can enter conveniently, more oil can be acted on, and turbulent flow is promoted to occur.

In this embodiment, as shown in fig. 4, an included angle formed by a connecting line between two adjacent transition points a and B of a transition point C of a spiral formed on the inner surface of the oil spray hole 6 by the convex rib 11 and the inner groove 12 and the transition point C is ≈_ACBAt an obtuse angle. So design, enlarged helical structure's pitch, the radian of protruding muscle strip 11 and inner groovy 12 spiral is less, and the fluid of being convenient for flows through nozzle 6, and it is residual to reduce fluid, can reduce the fluid and flow its whole resistance that receives of in-process to reduce the loss, avoid the obvious reduction of velocity of flow, the guarantee takes place the turbulent flow.

In this embodiment, the second protruding blocks 15 and the second grooves 16 are alternately distributed on the second protruding ribs 11 along the extending direction of the second protruding ribs 11. The oil flowing through the convex ribs 11 is subjected to the fluctuating acting force in the radial direction, and the turbulent flow is promoted to occur.

In the embodiment, the outer surface of the part of the conical end of the needle valve 3, which is positioned in the oil spray head 2, is provided with threads 5. When the needle valve 3 is opened, oil enters the oil spray head 2 at a high speed, and the oil on the periphery of the outer surface of the needle valve 3 flows along the threads 5, so that the possibility of turbulence is generated preliminarily; meanwhile, the oil center generates a driving force to the periphery, and the oil is promoted to enter the oil injection hole 6.

In the present embodiment, the injection hole 6 is provided in a portion of the injection head 2 surrounding the periphery of the needle 3. If the oil injection hole is arranged on the oil injection head 2 right in front of the needle valve 3, more oil can be injected from the oil injection hole 6, which is not favorable for the uniformity of oil injection; and as mentioned above, can produce the peripheral driving force by fluid center when the screw thread 5 that 3 toper ends of needle valve set up acts on, locate nozzle tip 2 around the position at 3 peripheries of needle valve with nozzle opening 6, accord with fluid flow direction demand.

The application process of the variable-frequency oil nozzle is as follows:

the needle valve 3 retreats, oil enters the oil spray head 2 from the oil spray cavity 4, the oil on the periphery of the outer surface of the needle valve 3 flows along the threads 5, the possibility of turbulence is generated preliminarily, and meanwhile, the driving force towards the periphery is generated by the center of the oil to promote the oil to enter the oil spray hole 6; after the oil enters the oil injection hole 6, at any time, part of the peripheral oil moves to the center under the action of the convex ribs 11 to extrude the central oil, and the other part of the peripheral oil moves to the periphery under the action of the inner grooves 12, so that the central oil supplements the moving oil, and the replacement motion of the peripheral oil and the central oil is realized; the spirally extending convex ribs 11 and the inner grooves 12 promote peripheral oil to spirally flow along the spiral structure, the spiral peripheral oil drives the central oil to spirally move, and the oil can comprehensively generate radial movement all the time, so that the oil generates turbulent flow; when the peripheral oil liquid flows through the convex blocks 13 and the concave grooves 14 (or the convex blocks 15 and the concave grooves 16), the radial action force of fluctuation is applied, and the radial fluctuation of the peripheral oil liquid is promoted, so that the mutual motion effect of the peripheral oil liquid and the central oil liquid is enhanced, and the generation of turbulent flow is further promoted. The molecules in the oil liquid move violently, the collision probability of the molecules is increased, the fuel oil is atomized better and comprehensively, and then the atomized oil liquid is sprayed out from the oil spray hole 6.

The detailed principle that oil can atomize through the oil spray hole 6 is:

when oil with certain viscosity flows on the surface of a uniform and consistent solid, laminar flow is easy to occur when the flow velocity is small, and turbulent flow is generated when the flow velocity is large; under the condition that other conditions are not changed, the pipeline is small in diameter and easy to generate laminar flow, and the pipeline is large in diameter and easy to generate turbulent flow. The atomization of the fuel can be measured by the Reynolds coefficient, R_eρ vd/μ, where ρ, v, μ are the density, flow rate and viscosity coefficient of the fluid, respectively, and d is the equivalent diameter of the oil jet. The larger the reynolds number is, the more irregular the internal movement is, the more likely the collision occurs, and the more favorable the atomization. At the same flow rate, density and pore size, the Reynolds number is completely dependent on the viscosity of the fluid and is the ratio of the inertial force to the viscous force. Set up protruding rib and inner groovy at the nozzle opening internal surface, different regions are different to the adsorption efficiency of fuel liquid column, consequently form the adhesive linkage or the adsorbed layer of different thickness on the nozzle opening inner wall. When oil flows along the oil injection hole, the radial movement in a droplet speed flow field is increased due to the change of radial fluctuation of the adsorption layer, so that the Reynolds number is increased; and convex rib and inner groovy all are equipped with lug and groove structure, produce the change of radial undulation again, further increase reynolds number. The molecular motion in the liquid drop is more violent, and the molecular motion frequency is increased, so that turbulent motion is easier to form, and the atomization effect of the fuel oil can be improved under the same condition, so that the fuel oil is easier to atomize.

According to the fluid mechanics principle, the flow rate and the internal pressure of oil liquid in the oil spray hole are changed by using the Reynolds number and adopting the spiral structure and the convex block and groove structure on the inner surface of the oil spray hole, so that the oil liquid is ensured to be comprehensively subjected to effective acting force, the turbulent flow is promoted, the internal molecular motion of the oil liquid in the oil spray hole is more violent, the molecular motion frequency is increased, the collision probability is increased, and the better atomization effect is realized. Compared with the traditional oil nozzle, the variable-frequency oil nozzle provided by the invention can reduce the required atomization pressure under the condition of achieving the same atomization effect, thereby saving energy consumption.

It should be understood by those skilled in the art that the above embodiments are only for illustrating the present invention and are not to be used as a limitation of the present invention, and that changes and modifications to the above embodiments are within the scope of the claims of the present invention as long as they are within the spirit and scope of the present invention.

Claims

1. A variable-frequency oil nozzle comprises an oil nozzle shell (1), an oil nozzle head (2) and a needle valve (3), wherein an oil injection cavity (4) is formed in a gap between the oil nozzle shell (1) and the needle valve (3), the oil nozzle head (2) is arc-shaped, the oil nozzle head (2) is positioned at one end of the oil nozzle shell (1), one end, where the needle valve (3) is positioned, of the oil nozzle head (2) is conical, the conical end of the needle valve (3) is tightly attached to the joint of the oil nozzle shell (1) and the oil nozzle head (2), and a plurality of oil injection holes (6) are formed in the oil nozzle head (2); the oil spray hole structure is characterized in that convex ribs (11) and inner grooves (12) which extend along the axial direction of the oil spray hole (6) are alternately distributed on the inner surface of the oil spray hole (6) along the circumference of the oil spray hole, and the convex ribs (11) and the inner grooves (12) both extend spirally along the axial direction of the oil spray hole (6); the inner grooves (12) are alternately distributed with lugs (13) and grooves (14) along the extending direction of the inner grooves (12); the cross section of the convex rib (11) is gradually narrowed from the inner wall surface of the connecting oil injection hole (6) to the opposite surface; the convex ribs (11) are alternately distributed with second convex blocks (15) and second grooves (16) along the extending direction of the convex ribs (11); the side wall of the inner groove (12) and the side edge of the corresponding convex rib (11) are positioned in the same plane, and the included angle between the plane and the bottom of the inner groove (12) is an obtuse angle.

2. The variable-frequency oil injection nozzle of claim 1, wherein the included angle formed by a connecting line between two adjacent transition points of the spiral transition point formed by the convex rib (11) and the inner groove (12) on the inner surface of the oil injection hole (6) and the transition point is an obtuse angle.

3. The variable-frequency oil injection nozzle according to claim 1, characterized in that the outer surface of the part of the conical end of the needle valve (3) located inside the oil injection head (2) is provided with threads (5).

4. The variable-frequency fuel injection nozzle according to claim 1, characterized in that the injection holes (6) are provided in the injection head (2) around the periphery of the needle valve (3).