CN109083879A - A method of inhibiting nozzle-flapper type servo valve prestage cavitation - Google Patents
A method of inhibiting nozzle-flapper type servo valve prestage cavitation Download PDFInfo
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- CN109083879A CN109083879A CN201810903744.2A CN201810903744A CN109083879A CN 109083879 A CN109083879 A CN 109083879A CN 201810903744 A CN201810903744 A CN 201810903744A CN 109083879 A CN109083879 A CN 109083879A
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- baffle
- square
- nozzle
- pressure
- spool
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B13/00—Details of servomotor systems ; Valves for servomotor systems
- F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
- F15B13/021—Valves for interconnecting the fluid chambers of an actuator
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B21/00—Common features of fluid actuator systems; Fluid-pressure actuator systems or details thereof, not covered by any other group of this subclass
- F15B21/08—Servomotor systems incorporating electrically operated control means
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15D—FLUID DYNAMICS, i.e. METHODS OR MEANS FOR INFLUENCING THE FLOW OF GASES OR LIQUIDS
- F15D1/00—Influencing flow of fluids
- F15D1/08—Influencing flow of fluids of jets leaving an orifice
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Details Of Valves (AREA)
Abstract
The invention discloses a kind of methods for inhibiting nozzle-flapper type servo valve prestage cavitation.Existing method air pocket inhibiting effect when pressure is larger can weaken.The electric signal of input is converted into flow stream pressure signal by torque-motor, nozzle and baffle by the present invention, is formed between two nozzles by relative position of the controllable register between two nozzles and the pressure difference at spool both ends, and then spool is pushed to be moved；Jet expansion is shaped to square, forms square jet stream, four strands can be divided into along the normal direction of square each side length after impact baffle plate plane penetrates and flow outwardly to.This feature of square impact jet flow can reduce flow velocity when baffle edge is left in radial jet, so that baffle and baffle be inhibited to place the air pocket in region between intracavitary wall surface；When liquid flow inlet pressure rise, speed increase when baffle edge is left in radial jet is smaller, so that cavitation is still effectively suppressed.
Description
Technical field
The present invention relates to a kind of electrohydraulic servo valve performance improvement methods, and in particular to a kind of inhibition nozzle baffle type is electro-hydraulic to be watched
The method for taking valve prestage cavitation.
Background technique
Electrohydraulic servo system has many advantages, such as good dynamic property, long service life, load stiffness are big, movement is steady,
Have in fields in aerospace, high-grade lathe and robot, high performance ship, advanced rail traffic, automobile, agricultural machinery etc.
It is widely applied background.Wherein, servo valve is the key that control element in electrohydraulic servo system, it can turn ultra-weak electronic signal
Be changed to the output of powerful hydraulic pressure signal, the quality of performance be the key that influence entire electrohydraulic servo system working performance because
Element.The form of servo valve is varied, and wherein nozzle-flapper servo valve has control precision height, fast response time, high sensitivity
The advantages that, it is widely used in electrohydraulic servo system.
In nozzle-flapper servo valve, prestage flow field is big with flowing shearing property, flow passage structure is more complex, inlet and outlet pressure
The features such as poor big, oil liquid flowing velocity is fast, is easy to produce local depression and then induces cavitation.It the generation of a large amount of bubbles and bursts
Meeting go out so that apparent pressure oscillation and noise occurs in prestage flow field.One side pressure oscillation can be such that baffle vibrates, shadow
Ring the job stability of armature retaining device.On the other hand, thus servo valve can generate high-frequency noise, cause noise jamming and dirt
Dye.In addition, element surface also occurs that cavitation erosion damage.Therefore, the generation of cavitation can seriously reduce the workability of servo valve
Can, and inhibiting servo valve prestage cavitation is the key that improve servo valve performance and prolong its service life.
Existing air pocket suppressing method mainly has setting outlet throttling or using rectangle baffle etc..The former can increase export
Back pressure reduces inlet outlet pressure differential, thus weaken cavitation, but this method also will increase the pressure in flow field around baffle, it is right
The movement of baffle has an impact.The latter eliminates the curved surfaces of baffle and extends the contact size of baffle and injection stream, right
Attachment air pocket at air pocket especially baffle has more apparent inhibiting effect, but this method changes the natural frequency of baffle
Etc. characteristics, the performance of armature baffle plate assembly is influenced.In addition, these methods charge oil pressure increase when, to cavitation
Inhibiting effect can be weakened.Therefore, it to improve the working performance of nozzle-flapper servo valve and prolonging its service life, needs
Design new air pocket suppressing method.In addition, having also appeared a kind of method for processing small jet hole on nozzle now, but the party
The small jet hole of method is easy blocking, and so as to cause failure, and small jet stream hole machined is relatively difficult.
Summary of the invention
The purpose of the present invention is in view of the deficiencies of the prior art, propose that a kind of inhibition nozzle-flapper type servo valve is preposition
The method of grade cavitation.
To achieve the above object, the present invention takes following technical scheme:
A kind of method for inhibiting nozzle-flapper type servo valve prestage cavitation of the present invention, specific as follows:
Influent stream source pressure fluid flows into first throttle channel through corresponding flow controller by the first inlet, and by the second feed liquor
Mouthful flow into the second throttling passage through corresponding flow controller, the pressure fluid of first throttle channel and the second throttling passage respectively via
Corresponding square outlet nozzle sprays to the plane of baffle two sides；When coil alives, armature is in magnetizer and permanent magnet
By the effect of electromagnetic torque in the magnetic field of formation, armature is made to deflect together with baffle, the deflection of baffle is so that two pros
Shape outlet nozzle and the gap of baffle side change, and side becomes larger, and the other side becomes smaller, and lead to the flow stream pressure at spool both ends
Also it changes, the pressure difference of one end pressure rise that gap becomes smaller, the pressure reduction of the other end, spool both ends generates work to spool
Firmly, the end motion for pushing spool low to pressure.The movement of spool makes feedback rod generate flexible deformation, generates opposing torque.
When the opposing torque of the electromagnetic torque, bourdon tube acted on armature and feedback rod opposing torque three reach balance, spool
Movement stops；And liquid stream exists after the ejection of square outlet nozzle and flows to baffle from square outlet nozzle and correspond to side plane
Impact jet flow and from the gap of square outlet nozzle and baffle flow to baffle place chamber inner wall radial jet；It is square
Influent stream road and out runner are opened up at the center of shape outlet nozzle；Influent stream road one end is connected to runner out, the other end and first throttle
Channel or the connection of the second throttling passage；It is circle into cross section of fluid channel, cross section of fluid channel is square out；Square outlet nozzle sprays
Square jet stream, the normal direction after impact baffle plate along square each side length, which is divided into four strands, penetrates and flows outwardly to, and reduces radial
Jet stream leaves flow velocity when baffle edge, so that baffle and baffle be inhibited to place the air pocket in region between intracavitary wall surface.
The diameter in the influent stream road is 1~2mm, and the side length of runner is 0.3~0.6mm out, and length is 0.5~1mm.
In the square section of runner out, the angle of the end face of a square diagonal line and baffle close to spool
It is 60~120 °.
The invention has the following advantages that
1, the inner flow passage outlet shapes of nozzle of the present invention are square, and a square wherein diagonal line and spray
Baffle side bottom edge corresponding to mouth can effectively inhibit servo valve prestage cavitation, especially cloud at 60~hexagonal angle
Air pocket.
2, the jet stream that nozzle of the present invention sprays is square impact jet flow, can be along each item of square after impact baffle plate
The normal direction of side length, which is divided into four strands, penetrates and flows outwardly to.Due to this feature of square impact jet flow, so that it is in liquid stream
Inlet pressure still can inhibit cavitation when increasing, therefore effectively weaken liquid stream variations in line pressure to nozzle baffle type
The influence of cavitation in electrohydraulic servo valve prestage flow field.
3, the suppressing method of cavitation of the present invention will not influence the frequency characteristic of armature baffle plate assembly, thus right
The frequency response characteristic of servo valve influences very little.
4, the runner of nozzle of the present invention is not easy to plug, and easy to process.
Detailed description of the invention
Fig. 1 is the nozzle-flapper servo valve structure principle chart that the present invention uses.
Fig. 2-1 is the servo valve nozzle and baffle position relation schematic diagram that the present invention uses.
Fig. 2-2 is that jet expansion opens up direction schematic diagram in embodiment.
When Fig. 3-1 is that nozzle inlet pressure is 5MPa and jet expansion shape is circle, servo valve prestage flow field is flat
Row is in the speed cloud atlas in the plane of nozzle spray direction.
When Fig. 3-2 is that nozzle inlet pressure is 5MPa and is square outlet nozzle, servo valve prestage flow field is parallel
In the speed cloud atlas in the plane of nozzle spray direction.
When Fig. 3-3 is that nozzle inlet pressure is 5MPa and is square outlet nozzle, servo valve prestage flow field is vertical
In the speed cloud atlas in the plane of nozzle spray direction.
When Fig. 4-1 is that nozzle inlet pressure is 5MPa and jet expansion shape is circle, servo valve prestage flow field is flat
Row is in the gas volume fraction cloud atlas in the plane of nozzle spray direction.
When Fig. 4-2 is that nozzle inlet pressure is 5MPa and is square outlet nozzle, servo valve prestage flow field is parallel
In the gas volume fraction cloud atlas in the plane of nozzle spray direction.
When Fig. 5-1 is that nozzle inlet pressure is 7MPa and jet expansion shape is circle, servo valve prestage flow field is flat
Row is in the gas volume fraction cloud atlas in the plane of nozzle spray direction.
When Fig. 5-2 is that nozzle inlet pressure is 7MPa and is square outlet nozzle, servo valve prestage flow field is parallel
In the gas volume fraction cloud atlas in the plane of nozzle spray direction.
Specific embodiment
The present invention is described in detail with reference to the accompanying drawing.
As shown in Figure 1, Figure 2 shown in -1 and 2-2, a kind of side inhibiting nozzle-flapper type servo valve prestage cavitation
Method, specific as follows:
Influent stream source pressure fluid flows into first throttle channel through corresponding flow controller 6 by the first inlet P1, and by second
Inlet P2 flows into the second throttling passage, the pressure fluid in first throttle channel and the second throttling passage through corresponding flow controller 6
The plane of 11 two sides of baffle is sprayed to via corresponding square outlet nozzle 12 respectively；When coil 3 alives, armature 2 exists
Effect in the magnetic field that magnetizer 9 and permanent magnet 7 are formed by electromagnetic torque, makes armature deflect together with baffle, baffle 11
Deflection so that two square outlet nozzles 12 and the gap of baffle side change, side becomes larger, and the other side becomes smaller, this
The flow stream pressure at 5 both ends of spool is caused also to change, one end pressure rise that gap becomes smaller, the pressure reduction of the other end, valve
The pressure difference at core both ends generates active force to spool, the end motion for pushing spool low to pressure.The movement of spool makes feedback rod 13
Flexible deformation is generated, opposing torque is generated.When the opposing torque and feedback rod of the electromagnetic torque, bourdon tube 8 that act on armature
When opposing torque three reaches balance, valve core movement stops；And liquid stream is after the ejection of square outlet nozzle 12, such as Fig. 3-1 and
Shown in 3-2, exists and flow to the impact jet flow 15 of the corresponding side plane of baffle 11 from square outlet nozzle 12 and from square outlet
The gap of nozzle and baffle flows to the radial jet 14 that baffle places the inner wall 1 of chamber；At the center of square outlet nozzle 12
Open up influent stream road 4 and out runner 10；4 one end of influent stream road is connected to runner 10 out, the other end and first throttle channel or the second section
Circulation road connection；It is circle into cross section of fluid channel, cross section of fluid channel is square out；It is 1~2mm, the out side of runner into flow diameter
A length of 0.3~0.6mm, length are 0.5~1mm.As shown in Fig. 2-2, out in the square section of runner, square one right
Linea angulata and baffle are into θ angle close to the end face of spool 5, and θ is 60~120 °；Square outlet nozzle 12 sprays square jet stream, punching
It hits the normal direction after baffle along square each side length and is divided into four strands and penetrates and flow outwardly to, reduce radial jet and leave baffle side
Flow velocity when edge, so that baffle and baffle be inhibited to place the air pocket in region between intracavitary wall surface.
As shown in Fig. 3-1,3-2 and 3-3, using computational fluid dynamics (CFD) to nozzle-flapper type servo valve before
It sets grade flow field and carries out numerical simulation calculating, due to the symmetry of the flow field structure, need to only calculate a quarter flow field (such as Fig. 2-1
Shown in dotted line frame).Nozzle-flapper type servo valve prestage flow field can be divided into nozzle and flow to rushing for 11 side of baffle
The gap directive baffle of slap shot stream 15 and nozzle and baffle places the radial jet 14 of the inner wall 1 of chamber.Inlet pressure is
21MPa (at this time in the present embodiment nozzle inlet pressure be 5MPa), and when jet expansion shape is round, speed is (single in flow field
Position be m/s numerical value represent flow velocity) cloud atlas as shown in figure 3-1, liquid stream radially flows out after nozzle directive baffle along baffle plane,
Form radial jet 14；And inlet pressure is 21MPa (nozzle inlet pressure is 5MPa in the present embodiment at this time), and using this
When the square outlet nozzle of invention, speed cloud atlas is as shown in Fig. 3-2 and 3-3 in flow field, it is seen then that due to using square outlet
Nozzle, the speed of radial jet 14 declines in flow field, i.e. radial jet is significantly attenuated.This is because square impact is penetrated
It flows normal direction after impact baffle plate along each side length and is divided into four strands and penetrates and flow outwardly to, and the region folded by adjacent two normal
Middle flowing is suppressed, as shown in Fig. 3-3, wherein arrow represents flow direction.
When liquid stream local pressure drops to air separation pressure or less, a large amount of micro-bubbles will be generated, and then be gathered into
Air pocket.Inlet pressure is 21MPa (nozzle inlet pressure is 5MPa in the present embodiment at this time), and jet expansion shape is circle
When, in flow field gas volume fraction (decimal in Fig. 4-1,4-2,5-1 and 5-2) cloud atlas as shown in Fig. 4-1, in nozzle edge and
Attachment air pocket 17 is produced at baffle edge, is placed in the region between intracavitary wall surface in baffle and baffle and is formd thin clouds cave
16；Inlet pressure is 21MPa (nozzle inlet pressure is 5MPa in the present embodiment at this time), and is gone out using square of the invention
Gas volume fraction cloud atlas is as shown in the Fig. 4-2 when mouthful nozzle, in flow field, it is seen then that thin clouds cave 16 no longer generates, this demonstrates this hair
Bright method can effectively inhibit cloud cavitation.Nozzle inlet pressure is 7MPa, and when jet expansion shape is round, in flow field
Gas volume fraction cloud atlas is as shown in fig. 5-1, it is seen then that in the case where nozzle inlet pressure increases 2MPa, the face in thin clouds cave 16
Product obviously increases；Nozzle inlet pressure is 7MPa, and when use square outlet nozzle of the invention, gas volume point in flow field
Number cloud atlas is as shown in Fig. 5-2, it is seen then that thin clouds cave does not generate still, this illustrates the method for the present invention for liquid flow inlet pressure
Serious cavitation caused by increase has good inhibitory effect, i.e., the air pocket inhibiting effect of the method for the present invention is by liquid flow inlet
The influence of pressure change is relatively small, this is because when nozzle inlet pressure increases, when baffle edge is left in radial jet
Speed increase is smaller, so that cavitation is still effectively suppressed.
Claims (3)
1. a kind of method for inhibiting nozzle-flapper type servo valve prestage cavitation, it is characterised in that: this method is specific
It is as follows:
Influent stream source pressure fluid flows into first throttle channel through corresponding flow controller by the first inlet, and is passed through by the second inlet
The pressure fluid of the second throttling passage of corresponding flow controller inflow, first throttle channel and the second throttling passage is respectively via correspondence
Square outlet nozzle spray to the planes of baffle two sides；When coil alives, armature is formed in magnetizer and permanent magnet
Magnetic field in effect by electromagnetic torque, so that armature is deflected together with baffle, the deflection of baffle is so that two squares go out
Mouth nozzle and the gap of baffle side change, and side becomes larger, and the other side becomes smaller, and the flow stream pressure at spool both ends is caused also to be sent out
The pressure difference of changing, one end pressure rise that gap becomes smaller, the pressure reduction of the other end, spool both ends acts on spool generation
Power, the end motion for pushing spool low to pressure；The movement of spool makes feedback rod generate flexible deformation, generates opposing torque；When
When the opposing torque of the electromagnetic torque, bourdon tube that act on armature and feedback rod opposing torque three reach balance, spool fortune
It is dynamic to stop；And liquid stream exists after the ejection of square outlet nozzle and flows to baffle from square outlet nozzle and correspond to side plane
Impact jet flow and from the gap of square outlet nozzle and baffle flow to baffle place chamber inner wall radial jet；Square
Influent stream road and out runner are opened up at the center of outlet nozzle；Influent stream road one end is connected to runner out, and the other end and first segment circulate
Road or the connection of the second throttling passage；It is circle into cross section of fluid channel, cross section of fluid channel is square out；Square outlet nozzle sprays just
Square jet, the normal direction after impact baffle plate along square each side length, which is divided into four strands, penetrates and flows outwardly to, and reduces radial penetrates
Stream leaves flow velocity when baffle edge, so that baffle and baffle be inhibited to place the air pocket in region between intracavitary wall surface.
2. a kind of method for inhibiting nozzle-flapper type servo valve prestage cavitation according to claim 1,
Be characterized in that: the diameter in the influent stream road is 1~2mm, and the side length of runner is 0.3~0.6mm out, and length is 0.5~1mm.
3. a kind of method for inhibiting nozzle-flapper type servo valve prestage cavitation according to claim 1,
It is characterized in that: in the square section of runner out, the folder of the end face of a square diagonal line and baffle close to spool
Angle is 60~120 °.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810903744.2A CN109083879B (en) | 2018-08-09 | 2018-08-09 | Method for inhibiting cavitation of preposed stage of nozzle baffle type electro-hydraulic servo valve |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201810903744.2A CN109083879B (en) | 2018-08-09 | 2018-08-09 | Method for inhibiting cavitation of preposed stage of nozzle baffle type electro-hydraulic servo valve |
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| Publication Number | Publication Date |
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| CN109083879A true CN109083879A (en) | 2018-12-25 |
| CN109083879B CN109083879B (en) | 2020-06-23 |
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| CN201810903744.2A Active CN109083879B (en) | 2018-08-09 | 2018-08-09 | Method for inhibiting cavitation of preposed stage of nozzle baffle type electro-hydraulic servo valve |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110639851A (en) * | 2019-09-19 | 2020-01-03 | 白海山 | Electro-hydraulic servo system for conveying equipment |
| CN110905878A (en) * | 2019-10-29 | 2020-03-24 | 中国航空工业集团公司西安飞行自动控制研究所 | Pressure-mounting type front-stage deflection plate jet flow servo valve |
| CN112604863A (en) * | 2020-12-28 | 2021-04-06 | 广州媛爱贸易有限公司 | Automatic pressing-in equipment for nozzle of electro-hydraulic servo valve |
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| US3857541A (en) * | 1973-06-14 | 1974-12-31 | Moog Inc | Servovalve with oscillation filter |
| CN201714727U (en) * | 2010-02-26 | 2011-01-19 | 同济大学 | Nozzle baffle valve with damping throttler |
| CN106640821A (en) * | 2017-02-10 | 2017-05-10 | 同济大学 | Dual-redundancy rebounding jet flow inclined guide plate servo valve |
| CN108302080A (en) * | 2018-02-11 | 2018-07-20 | 杭州电子科技大学 | The method that nozzle-flapper servo valve inhibits prestage cavitation |
-
2018
- 2018-08-09 CN CN201810903744.2A patent/CN109083879B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3857541A (en) * | 1973-06-14 | 1974-12-31 | Moog Inc | Servovalve with oscillation filter |
| CN201714727U (en) * | 2010-02-26 | 2011-01-19 | 同济大学 | Nozzle baffle valve with damping throttler |
| CN106640821A (en) * | 2017-02-10 | 2017-05-10 | 同济大学 | Dual-redundancy rebounding jet flow inclined guide plate servo valve |
| CN108302080A (en) * | 2018-02-11 | 2018-07-20 | 杭州电子科技大学 | The method that nozzle-flapper servo valve inhibits prestage cavitation |
Non-Patent Citations (1)
| Title |
|---|
| 石油大学（华东）青年科学技术协会: "《石油科技发展与研究》", 31 December 1996 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110639851A (en) * | 2019-09-19 | 2020-01-03 | 白海山 | Electro-hydraulic servo system for conveying equipment |
| CN110639851B (en) * | 2019-09-19 | 2021-07-13 | 山东联创高科自动化有限公司 | Electro-hydraulic servo system for conveying equipment |
| CN110905878A (en) * | 2019-10-29 | 2020-03-24 | 中国航空工业集团公司西安飞行自动控制研究所 | Pressure-mounting type front-stage deflection plate jet flow servo valve |
| CN112604863A (en) * | 2020-12-28 | 2021-04-06 | 广州媛爱贸易有限公司 | Automatic pressing-in equipment for nozzle of electro-hydraulic servo valve |
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| Publication number | Publication date |
|---|---|
| CN109083879B (en) | 2020-06-23 |
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