CN102789517B - Method for changing flow-displacement nonlinearity of water inlet valve core of hydraulic press - Google Patents

Abstract

The invention provides a method for changing the flow-displacement nonlinearity of a water inlet valve core of a hydraulic press. The method mainly comprises the following steps of: carrying out mathematic modeling on the flow-displacement nonlinearity of the water inlet valve core according to the valve cup water inlet arrangement of the water inlet valve core; analyzing by utilizing an MATLAB (Matrix Laboratory) software program, determining the value of an overlap ratio y and further determining the valve cup water inlet arrangement mode so as to enable the flow-displacement nonlinearity of the water inlet valve core to be minimal; and establishing a water inlet valve core model with the valve cup water inlet arrangement and an original water inlet valve core geometric model in Gambit software, introducing the models established in the Gambit software into a Fluent, performing flow field analysis and solution, and performing flow field simulation by virtue of the Fluent so as to obtain flow-displacement curves before and after the valve cup water inlet arrangement is changed. The water inlet valve core, regulated by virtue of the method provided by the invention, of the hydraulic press can be used for controlling the speed of a movable cross beam more accurately, reducing the vibration of the hydraulic press and improving the quality of forgings.

Description

A kind of method that changes water pressure engine water inlet spool flow-non-linear displacement

Technical field

The present invention relates to a kind of water pressure engine water inlet spool valve cup, proposed a kind of method that changes its flow-non-linear displacement for described water inlet spool valve cup.

Background technology

When hydraulic forging press normally forges, its working cycle comprises " enter-release of (topping up)-deceleration-work under fast-return to ", this working cycle realizes by main allocated equipment, and main allocated equipment key element is into water spool and draining valve, be the corresponding water-inflow and drain valves of opening and closing, control the action of water pressure engine moved cross beam, determine the processes process of water pressure engine.When eharge stroke, main allocated equipment kicker cylinder draining valve is opened, and moved cross beam declines by deadweight, low pressure

Liquid in compensator enters working cylinder through prefill valve, realizes the downward eharge stroke of moved cross beam idle running; When work is carried out journey, main allocated equipment working cylinder water inlet spool is opened, and highly pressurised liquid enters working cylinder, realizes workpiece pressurization, and now, kicker cylinder draining valve continues to open discharge opeing; When backhaul, working cylinder water inlet spool is closed, and master cylinder tapping valve is opened release subsequently, and then kicker cylinder water inlet spool opens, highly pressurised liquid water inlet kicker cylinder, opens prefill valve, moved cross beam moves upward under highly pressurised liquid effect, makes the liquid in working cylinder enter pressure-loaded prefilling tank or low-voltage compensation device; When unsettled, working cylinder draining valve continues to open, and working cylinder leads to low pressure, and now kicker cylinder water inlet spool and draining valve are all closed, and liquid is enclosed in kicker cylinder, therefore moved cross beam can be parked in optional position.

From the processes process of above-mentioned water pressure engine, find out, water inlet spool be the key component of main allocated equipment, water inlet spool structures shape dydraulic forging workpiece time flow, i.e. Forging Equipment Speed.The linearity that existing water intaking valve cored structure flow changes with opening degree is poor, and this just causes in forging process system speed unstable, and precision is forged in impact.

In operating system of water press, due to flow and pressure large, water inlet spool adopt cone valve structure, valve rod, with the conical surface and valve seat phase bedding-in, has water inlet on valve cup, has spring to push down above valve rod, divider is stretched out in lower end, all there are packoff and guide pin bushing in two ends.

In order to control more accurately the work speed of water pressure engine moved cross beam, on the valve cup of water inlet spool, offer number row aperture, in the time that valve opening height is different, flow area is also different, controls water pressure engine flow with this, thereby controls the operating rate of moved cross beam.

On tradition water inlet spool valve cup, the mode of perforate has three kinds:

(1) aperture equates, many rows are uniformly distributed, and the spacing between adjacent two rounds equates;

(2) aperture equates, arranges uneven distribution more, and from the bottom up, every round number increases gradually, and the spacing between adjacent two rounds equates;

(3) aperture not etc., does not increase from the bottom up gradually, and the spacing between adjacent two rounds equates.

Draw from reality processing and practical experience: the latter is convenient to control more accurately moved cross beam speed, the above two are convenient to processing.

In the water inlet spool standard JB2025-84 of Ministry of Machine-Building Industry, water pressure engine water inlet spool valve cup adopts above-mentioned (1) to plant perforate mode, but along with the increase of spool displacement, its flow presents obvious nonlinear wave, can not control exactly water pressure engine moved cross beam speed.

Summary of the invention

The object of the present invention is to provide a kind of being convenient under the prerequisite of processing, change water inlet spool flow-non-linear displacement, thereby control more accurately moved cross beam speed, reduce press vibration, improve a kind of method that changes water pressure engine water inlet spool flow-non-linear displacement of forging quality.

The present invention is mainly: arrange according to the valve cup water inlet of water inlet spool, the flow-placement property of water inlet spool is carried out to mathematical modeling; Use the analysis of MATLAB software program, determine registration y value and then determine that valve cup water inlet arrangement form makes into water spool flow-non-linear displacement minimum; In Gambit software, set up and there is water intaking valve core model that above-mentioned valve cup water inlet arranges and the geometric model of former water inlet spool, solve carry out flow field analysis in the model importing Fluent setting up in Gambit software, Fluent flow field simulation draws flow-displacement curve that valve cup water inlet is arranged before and after changing.

Water intaking valve cored structure and the prior art of the main allocated equipment the present invention relates to are basic identical, mainly comprise: guide rod, spring, nut, plug screw, valve cup, screw, pressure-release valve, valve seat, guide pin bushing, support ring, valve, spacing plug screw, sealing socket, support ring, baffle plate, regulating sleeve and nut.Wherein, under above-mentioned valve cup, barrel is provided with the circular water inlet of some rows, and every row inlet opening number is identical, and all inlet openings diameter is identical, staggered between every two row inlet openings, and between every two row's water inlets, area is axially having certain registration.

The above-mentioned water inlet spool course of work is divided into two stages of opening and closing, detailed process: opening process comprises pre-unlatching and standard-sized sheet, opening force acts on pressure-release valve valve rod, first pressure-release valve is opened, valve epicoele high pressure is laid down by the gas pressure relief slot on spacing plug screw, pressure-release valve valve port and valve, and the pressure that valve cup upper end water inlet can not replenishment valve epicoele be laid down, thereby valve epicoele high pressure becomes low pressure, completes pre-unlatching; After pre-unlatching, valve is opened completely with less opening force, after valve standard-sized sheet, the some row water inlets of water under high pressure from valve cup flow into, and flow out from water delivering orifice, and the row of water inlet work is determined by the displacement of valve, when displacement one timing of valve, water inlet number is determined, thus the flow area of decision water inlet spool, and flow area can be determined the flow of water inlet spool; Closing process is also divided into two stages, first closes pressure-release valve, under the hydraulic coupling acting in conjunction of the water under high pressure of then coming at spring force and water inlet spool water inlet, and valve safety shutdown.

The present invention changes the method for water inlet spool flow-non-linear displacement, mainly comprises three aspects:: mathematical modeling, software program analysis, the process analysis of flow field analysis verifying software.

1. mathematical modeling

According to the above-mentioned valve cup water inlet calculating flow area of arranging:

(1), when 0<x< (2r-yr), have

$A=m\left\{\arccos \right[(r-x)/r]-\sqrt{2\mathrm{rx}-x^2}(r-x)\}$

(2) as [2nr-(n-1) yr] <x<[2 (n+1) r-(n+1) yr] time, wherein n=1,2,3... (N-1), has

$A=m\left\{r^2\arccos \right\{[r-(x-2\mathrm{nr}+\mathrm{nyr})]/r\}\sqrt{2r(x-2\mathrm{nr}+\mathrm{nyr})-(x-2\mathrm{nr}+\mathrm{nyr})}+{\mathrm{n\&pi;r}}^2\}$

(3) as (2nr-nyr) <x<[2nr-(n-1) yr] time, wherein n=1,2,3... (N-1), has

$A=m\left\{r^2\arccos \right\{[r-2(n-1)r+(n-1)\mathrm{yr}]/r\}-\{r-[x-2(n-1)r+(n-1)\mathrm{yr}]\}$

$\sqrt{2r[x-2(n-1)r+(n-1)\mathrm{yr}]-{[x-2(n-1)r+(n-1)\mathrm{yr}]}^2}+r^2\arccos \left\{\right[r-(x-2\mathrm{nr}+\mathrm{nyr})]/r\}$

$-[r-(x-2\mathrm{nr}+\mathrm{nyr})]\sqrt{2r(x-2\mathrm{nr}+\mathrm{nyr})-{(x-2\mathrm{nr}+\mathrm{nyr})}^2}+(n-1)\mathrm{\&pi;}{r}^2\}$

(4) as (2nr-nyr) <x<[2nr-(n-1) yr] time, wherein n=N, has

$A=m\{(n-1)\mathrm{\&pi;}{r}^2+r^2\arccos \{[r-(x-8r+4\mathrm{yr})]/r\}-$

$\sqrt{2r[x-2(n-1)r+(n-1)\mathrm{yr}]-{[x-2(n-1)r+(n-1)\mathrm{yr}]}^2}$

$\{r-[x-2(n-1)r+(n-1)\mathrm{yr}\left]\right\}\}$

Registration expression formula:

$y=\frac{2r-L_r}{r}$

Wherein, r is inlet opening radius; Y is the registration between two rounds; X is the opening degree of water inlet spool; N is the total row in inlet opening; M is the number of every round; A is flow area; L _rbe represented as the distance between the adjacent two row centers of circle, inlet opening.

According to flow rate calculation formula:

$q=C_{q}A\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

Wherein: q is flow; C _qfor coefficient of flow; A is flow area; ρ is fluid density; Δ P is pressure reduction before and after valve port; Obtain into the computing formula of water spool " flow-displacement ":

(1), when 0<x< (2r-yr), have

$q=C_{q}m\left\{\arccos \right[(r-x)/r]-\sqrt{2\mathrm{rx}-x^2}(r-x)\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

(2) as [2nr-(n-1) yr] <x<[2 (n+1) r-(n+1) yr] time, wherein n=1,2,3... (N-1), has

$q=C_{q}m\left\{r^2\arccos \right\{[r-(x-2\mathrm{nr}+\mathrm{nyr})]/r\}\sqrt{2r(x-2\mathrm{nr}+\mathrm{nyr})-(x-2\mathrm{nr}+\mathrm{nyr})}$

$+\mathrm{n\&pi;}{r}^2\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

(3) as (2nr-ny) <x<[2nr-(n-1) y] time, wherein n=1,2,3... (N-1), has

$q=C_{q}m\left\{r^2\arccos \right\{[r-2(n-1)r+(n-1)\mathrm{yr}]/r\}-\{r-[x-2(n-1)r+(n-1)\mathrm{yr}]\}$

$\sqrt{2r{[x-2(n-1)r+(n-1)\mathrm{yr}]-[x-2(n-1)r+(n-1)\mathrm{yr}]}^2}+r^2\arccos \left\{\right[r-(x-2\mathrm{nr}+\mathrm{nyr})]/r\}$

$-[r-(x-2\mathrm{nr}+\mathrm{nyr})]\sqrt{2r(x-2\mathrm{nr}+\mathrm{nyr})-{(x-2\mathrm{nr}+\mathrm{nyr})}^2}+(n-1){\mathrm{\&pi;r}}^2\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

(4) as (2nr-nyr) <x<[2nr-(n-1) yr] time, wherein n=N, has

$q=C_{q}m\{(n-1)\mathrm{\&pi;}{r}^2+r^2\arccos \{[r-(x-8r+4\mathrm{yr})]/r\}-$

$\sqrt{2r[x-2(n-1)r+(n-1)\mathrm{yr}]-{[x-2(n-1)r+(n-1)\mathrm{yr}]}^2}$

$\{r-[x-2(n-1)r+(n-1)\mathrm{yr}\left]\right\}\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

2. software program analysis

Utilize MATLAB software to programme to above-mentioned flow-displacement computing formula, this MATLAB software programming process is as follows:

1.. statement variable

Defining variable: r-inlet opening radius, the total row in N-inlet opening, x-spool displacement, A-flow area, y-registration, Cq-coefficient of flow, the number of the every round of m-, q-flow, p-pressure reduction, d-density.

2.. give variable assignments

For example: make r=4, N=5, m=30 etc.By for registration y composes different numerical value, can obtain the flow-displacement curve under different registrations.

3.. programme according to theoretical calculation formula

Programme according to above-mentioned water inlet spool " flow-displacement " computing formula (1), (2), (3), (4) respectively, the flow-displacement curve can draw out registration y and get different value time.The size that can observe out y value from curve has a significant impact the non-linear of flow-displacement, and ensureing that in valve cup, the wall thickness between any two holes is tried one's best under large prerequisite, y value is larger, flow-displacement non-linear less, and the linearity is better.

Utilize above-mentioned MATLAB process analysis, can determine registration y value, and then determined that the inlet opening structure of valve cup arranges.

3. flow field analysis verifying software process analysis result

(1) Gambit modeling

A. set up geometric model sets up and has water intaking valve core model that above-mentioned valve cup water inlet arranges and the geometric model of former water inlet spool in Gambit software, because set up model is centrosymmetric, getting wherein 1/m (m is the number of every row inlet opening) analyzes, save computer running time, improve operation efficiency and not impact analysis result;

B. grid division is to above-mentioned geometric model grid division, and water inlet grid is suitably encrypted, and ensures computational accuracy;

C. be the appropriate boundary condition of the model specification boundary condition appropriate to the setting of above-mentioned model, import boundary types PRESSURE_INLET, outlet boundary types PRESSURE_OUTLET.

(2) Fluent flow field analysis

Solve carry out flow field analysis in the model importing Fluent building up in Gambit.

A. set solver and adopt acquiescence form: the implicit detach method of stable state.

B. set mathematical model and adopt standard k-ε model

C. set the attribute that material attribute material attribute is water, density 998kg/m ³, kinetic viscosity μ=1.01 × 10 ^-3pas.

D. starting condition set pressure inlet pressure is 32000000Pa, and pressure export pressure is 30000000Pa.

E. set the each variable convergence of convergence and iterations residual error and be made as 10 ^-3, primary iteration number of times is according to concrete model setting.

Set the laggard row iteration of above-mentioned parameter and calculate, until calculate convergence, save data.

Change the spool displacement in model, repeat said process, flow field analysis result can obtain different spool displacement time, from flow value corresponding to the different spool displacements of extracting data of preserving, the data obtained is processed, can obtain respectively the flow-displacement curve of two models, from curve, also can find out that water inlet spool flow-displacement non-linear that changes valve cup structure compare former water inlet spool and greatly reduce, thus the correctness of checking this method.

Brief description of the drawings

Fig. 1 is that DN100 water inlet spool master looks section simplified schematic diagram;

Fig. 2 is that the valve cup master of DN100 water inlet spool looks section simplified schematic diagram;

Fig. 3 is the C-C view of Fig. 2;

Fig. 4 is the local expansion figure of Fig. 2;

Fig. 5 is flow-displacement curve figure that MATLAB calculates;

Fig. 6 is the y=0DN100 water inlet spool geometric model figure that Gambit sets up;

Fig. 7 is the y=0.9DN100 water inlet spool geometric model figure that Gambit sets up;

Fig. 8 is flow-displacement numerical value and the curve map that Fluent emulation draws.

Drawing reference numeral is described as follows: 1. water inlet 26. exhalant canals of the spacing plug screw 20. sealing socket 21. support ring 22. baffle plate 23. regulating sleeve 24. nut 25. valve cups of guide rod 2. spring 3. nut 4. plug screw 5.U shape O-ring seal 6.O shape O-ring seal 7. valve cup 8. screw 9. pressure-release valve 10. valve seat 11.O RunddichtringO 12.U shape O-ring seal 13. plug screw 14.O shape O-ring seal 15. guide pin bushing 16. support ring 17.O shape O-ring seal 18. valve 19..

The present invention is described in further details by example below in conjunction with accompanying drawing, but following example is only the present invention's example wherein, do not represent the rights protection scope that the present invention limits, the scope of the present invention is as the criterion with claims.

Embodiment

Set forth the method for this change water inlet spool flow-non-linear displacement below as example is concrete taking the water inlet spool of DN100.

Look in section simplified schematic diagram the water inlet spool master shown in Fig. 1, the outer surface cover of inverted T-shaped guide rod has spring, and the outer surface cover of spring has regulating sleeve, and this regulating sleeve upper end is provided with the nut engaging with it, and lower end is placed in plug screw central through hole.Be positioned at the clamp nut that the regulating sleeve peripheral hardware of plug screw outside engages with it.Above-mentioned plug screw central through hole bottom is provided with the upper end pressure-release valve valve rod adjacent with lower end of the guide rod, this pressure-release valve valve rod is from top to bottom successively through spacing plug screw and valve in sealing socket and valve cup and valve seat, again through exhalant canal, bottom from top to bottom, again successively through guide pin bushing, support ring and lower plug screw, then reaches outside valve body.Above-mentioned plug screw lower end is connected with sealing socket, is provided with the U-shaped O-ring seal, support ring and the baffle plate that are enclosed within pressure-release valve valve rod outside in sealing seat center pit.Sealing seat following peripheral is connected with the limit, upper end of valve cup, and this limit, valve cup lower end is connected with limit, valve seat upper end.Under above-mentioned valve cup, barrel is provided with the circular water inlet of some rows, and every row inlet opening number is identical, and all inlet openings diameter is identical, staggered between every two row inlet openings, and between every two row's water inlets, area is axially having certain registration.In above-mentioned valve cup, be provided with the valve that bottom and valve seat coordinate, Yu Fabei chamber, top is corresponding, the upper shed of this groove type valve is provided with the spacing plug screw being threaded with it, this spacing plug screw central through hole lower end is stuck on the shaft shoulder of pressure-release valve valve rod, central through hole is established some small through hole parallel with its axis around, and it is pressure relief groove that valve bottom is provided with some through holes.

The course of action of DN100 water inlet spool: when open (1), opening force acts on the valve rod of pressure-release valve 9, first pressure-release valve opens 2mm (this trip is adjusted by spacing plug screw 19), valve 18 upper cavity pressures make valve upper cavity pressure shed a part by the pressure relief groove on spacing plug screw 19, pressure-release valve 9 valve ports and valve 18, and valve cup 7 upper end water inlets have little time to supplement the pressure of laying down to valve 18 epicoeles, so just can reduce the pressure of valve 18 epicoeles, promote pressure-release valve 19 with less opening force and drive valve 18 to open.(2) after water inlet spool is opened, the water inlet of water under high pressure from the valve cup 7 of water inlet spool flows into from water delivering orifice and flows out, and the row of water inlet work is determined by the displacement of valve 18, along with the increase of valve 18 displacements, 5 row's water inlets are worked successively, and flow increases thereupon.(3) while closing into water spool, pressure-release valve 9 first cuts out, and under the acting in conjunction of the spring force of spring 2 and the hydraulic coupling of water under high pressure, water inlet spool is closed completely.

The valve cup structure of DN100 water inlet spool as shown in Figure 2, Figure 3 and Figure 4, has 5 row's water inlets on valve cup, every row is 30, and each water inlet diameter is between 8, two row's water inlets staggered, and the registration between two rounds is made as y.

According to the valve cup structure in Fig. 2, Fig. 3 and Fig. 4, available said method changes flow-displacement non-linear of water inlet spool.

The DN100 water inlet flow of spool and the relational expression of spool displacement are the calculating formula of above-mentioned flow-displacement:

(1) when 0<x< (2r-yr),

$q=C_{q}m\left\{\arccos \right[(r-x)/r]-\sqrt{2\mathrm{rx}-x^2}(r-x)\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

(2) as [2nr-(n-1) yr] <x<[2 (n+1) r-(n+1) yr] time, wherein n=1,2,3... (N-1)

$q=C_{q}m\left\{r^2\arccos \right\{[r-(x-2\mathrm{nr}+\mathrm{nyr})]/r\}\sqrt{2r(x-2\mathrm{nr}+\mathrm{nyr})-(x-2\mathrm{nr}+\mathrm{nyr})}$

$+\mathrm{n\&pi;}{r}^2\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

(3) as (2nr-nyr) <x<[2nr-(n-1) yr] time, wherein n=1,2,3... (N-1)

$q=C_{q}m\left\{r^2\arccos \right\{[r-2(n-1)r+(n-1)\mathrm{yr}]/r\}-\{r-[x-2(n-1)r+(n-1)\mathrm{yr}]\}$

$\sqrt{2r{[x-2(n-1)r+(n-1)\mathrm{yr}]-[x-2(n-1)r+(n-1)\mathrm{yr}]}^2}+r^2\arccos \left\{\right[r-(x-2\mathrm{nr}+\mathrm{nyr})]/r\}$

$-[r-(x-2\mathrm{nr}+\mathrm{nyr})]\sqrt{2r(x-2\mathrm{nr}+\mathrm{nyr})-{(x-2\mathrm{nr}+\mathrm{nyr})}^2}+(n-1){\mathrm{\&pi;r}}^2\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

(4) as (2nr-nyr) <x<[2nr-(n-1) yr] time, wherein n=N

$q=C_{q}m\{(n-1)\mathrm{\&pi;}{r}^2+r^2\arccos \{[r-(x-8r+4\mathrm{yr})]/r\}-$

$\sqrt{2r[x-2(n-1)r+(n-1)\mathrm{yr}]-{[x-2(n-1)r+(n-1)\mathrm{yr}]}^2}$

$\{r-[x-2(n-1)r+(n-1)\mathrm{yr}\left]\right\}\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

Wherein r=8, N=5, m=30.Therefore can be the variable r in above-mentioned MATLAB program, N, m assignment, wherein r=8, N=5, m=30, be made as the value of y by changing registration between two row inlet openings, get respectively y=0 and y=0.25,0.35,0.45,0.5 contrast, can obtain the q-x curve of flow q and spool displacement x.Flow displacement-the curve of this DN100 water inlet spool as shown in Figure 5, as can be seen from the figure when y=0, while being former water inlet spool, flow-displacement curve non-linear very serious, by changing the value of registration y, can find out that the non-linear of flow-displacement progressively reduces along with the increase of registration from 0.25 to 0.5, the linearity is become better and better.

From Fig. 2, Fig. 3 and Fig. 4, can find out the increase along with y value, the wall thickness between adjacent holes is more and more less, and this will weaken the intensity of valve cup; As can be seen from Figure 5 in the time of y=0.45 and y=0.5, the linearity of flow-displacement curve is very approaching, continues to increase y value also very little to the non-linear effects of curve; Therefore consider valve cup intensity and flow-non-linear displacement, get registration y=0.45.

Use Gambit software to set up the geometric model of registration y=0 and y=0.45, as shown in Figure 6 and Figure 7, because set up model is centrosymmetric, get wherein 1/30 (the 30th, the number of every row's water inlet) as final geometric model, to geometric model grid division, import boundary types PRESSURE_INLET, outlet boundary types PRESSURE_OUTLET.

The model that Gambit is set up imports in Fluent and carries out flow field analysis, and according to above-mentioned Fluent flow field analysis process parameters, then solves calculating, until the convergence of each parameter residual error, save data.

Change the spool displacement in model, repeat said process, the flow field analysis data just can obtain different spool displacement time, from the value of these extracting data mass flows, the flow value can obtain different spool displacement through calculating time, as shown in the table:

Upper table data are processed and just can be obtained flow-displacement curve, and as shown in Figure 8, as can be seen from the figure, the curve of registration y=0.45 is better than the curve smoothing of registration y=0 and the linearity, can verify the correctness of said method for curve.

Claims (4)

1. one kind changes the method for water pressure engine water inlet spool flow-non-linear displacement, it is characterized in that: arrange according to the valve cup water inlet of water inlet spool, flow-placement property to water inlet spool carries out mathematical modeling, calculates into the flow-displacement formula of water spool by theory:

(1) when 0<x< (2r-yr),

$q=C_{q}m\left\{\arccos \right[(r-x)/r]-\sqrt{2\mathrm{rx}-x^2}(r-x)\}\sqrt{\frac{1}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}$

(2) as [2nr-(n-1) yr] <x<[2 (n+1) r-(n+1) yr] time, wherein n=1,2,3... (N-1)

$\begin{array}{c}q=C_{q}m\left\{r^2\arccos \right\{[r-(x-2\mathrm{nr}+\mathrm{nyr})]/r\}\sqrt{2r(x-2\mathrm{nr}+\mathrm{nyr})-(x-2\mathrm{nr}+\mathrm{nyr})}\\ +{\mathrm{n\&pi;r}}^2\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}\end{array}$

(3) as (2nr-nyr) <x<[2nr-(n-1) yr] time, wherein n=1,2,3... (N-1)

$\begin{array}{c}q=C_{q}m\left\{r^2\arccos \right\{[r-2(n-1)r+(n-1)\mathrm{yr}]/r\}-\{r-[x-2(n-1)r+(n-1)\mathrm{yr}]\}\\ \sqrt{2r{[x-2(n-1)r+(n-1)\mathrm{yr}]-[x-2(n-1)r+(n-1)\mathrm{yr}]}^2}+r^2\arccos \left\{\right[r-(x-2\mathrm{nr}+\mathrm{nyr})]/r\}\\ -[r-(x-2\mathrm{nr}+\mathrm{nyr})]\sqrt{2r(x-2\mathrm{nr}+\mathrm{nyr})+{(x-2\mathrm{nr}+\mathrm{nyr})}^2}+(n-1){\mathrm{\&pi;r}}^2\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}\end{array}$

(4) as (2nr-nyr) <x<[2nr-(n-1) yr] time, wherein n=N

$\begin{array}{c}q=C_{q}m\{(n-1)\mathrm{\&pi;}{r}^2+r^2\arccos \{[r-(x-8r+4\mathrm{yr})]/r\}-\\ \sqrt{2r[x-2(n-1)r+(n-1)\mathrm{yr}]-{[x-2(n-1)r+(n-1)\mathrm{yr}]}^2}\\ \{r-[x-2(n-1)r+(n-1)\mathrm{yr}\left]\right\}\}\sqrt{\frac{2}{\mathrm{\&rho;}}\mathrm{\&Delta;P}}\end{array}$

In formula: q represents flow; C _qrepresent coefficient of flow; ρ represents the density of water; Δ P represents water valve two ends pressure reduction; R represents inlet opening radius; Y represents the registration between two rounds; The opening degree of x representative water inlet spool; N represents the total row in inlet opening; M represents the number of every round;

Use the analysis of MATLAB software program, determine registration y value and then determine that valve cup water inlet arrangement form makes into water spool flow-non-linear displacement minimum; In Gambit software, set up and there is water intaking valve core model and the former water inlet spool geometric model that above-mentioned valve cup water inlet is arranged, the model of setting up is imported to flow field analysis in Fluent solve in Gambit software:

A. set solver and adopt acquiescence form: the implicit detach method of stable state;

B. set mathematical model and adopt standard k-ε model;

C. set the attribute of material attribute water, density 998kg/m ³, kinetic viscosity μ=1.01 × 10 ^-3pas;

D. starting condition set pressure inlet pressure is 32000000Pa, and pressure export pressure is 30000000Pa;

E. set the each variable convergence of convergence and iterations residual error and be made as 10 ^-3, primary iteration number of times is according to concrete model setting;

Setting the laggard row iteration of the described parameter of a-e calculates, until calculate convergence, save data, change the water inlet valve core opening degree in model, repeat said process, flow field analysis result can obtain different water inlet valve core opening degree time, from flow value corresponding to the different spool displacements of extracting data of preserving, the data obtained is processed, can obtain respectively water intaking valve core model that valve cup water inlet flow-non-linear displacement minimum arranges and the flow-displacement curve of former water inlet spool geometric model, Fluent flow field simulation draws flow-displacement curve that valve cup water inlet is arranged before and after changing.

2. a kind of water pressure engine water inlet spool flow-non-linear displacement method that changes according to claim 1, is characterized in that: registration expression formula:

$y=\frac{2r-L_r}{r}$

In formula: r represents inlet opening radius; Y represents the registration between two rounds; Lr represents the distance between the adjacent two row centers of circle, inlet opening.

3. a kind of method that changes water pressure engine water inlet spool flow-non-linear displacement according to claim 2, is characterized in that: utilize MATLAB software to programme to above-mentioned flow-displacement computing formula, this MATLAB software programming process is as follows:

1. state variable

Defining variable: opening degree, y-registration, the C of r-inlet opening radius, the total row in N-inlet opening, x-water inlet spool _qthe number of-coefficient of flow, the every round of m-, q-flow;

2. give variable assignments

By for registration y composes different numerical value, can obtain the flow-displacement curve under different registrations;

3. programme according to theoretical calculation formula

Programme according to above-mentioned water inlet spool " flow-displacement " computing formula (1), (2), (3), (4) respectively, the flow-displacement curve can obtain registration y and get different value time;

Utilize above-mentioned MATLAB process analysis, can determine registration y value, and then determined that the inlet opening structure of valve cup arranges.

4. a kind of method that changes water pressure engine water inlet spool flow-non-linear displacement according to claim 3, is characterized in that: the process analysis of flow field analysis verifying software:

(1) Gambit modeling

A. in Gambit software, set up and there is water intaking valve core model that above-mentioned valve cup water inlet arranges and the geometric model of former water inlet spool;

B. grid division is to above-mentioned geometric model grid division;

C. be the appropriate boundary condition of model specification, import boundary types PRESSURE_INLET, outlet boundary types PRESSURE_OUTLET;

(2) Fluent flow field analysis

Solve carry out flow field analysis in the model importing Fluent building up in Gambit.