Summary of the invention
The technical problems to be solved in the utility model is, a kind of mode of structure of new high-differential-pressure regulating valve is provided, adopt the valve of this kind of structure under the prerequisite realizing High Pressure Difference adjustment, highly sensitive pressure can be realized and regulate, and propose a kind of pressure regulating method and realize the system of its method.
The technical solution of the utility model is: a kind of high-differential-pressure regulating valve, comprise spool, valve seat and valve body, valve body is provided with the entrance be communicated with successively, cavity and outlet, spool and valve seat are arranged in the cavity set by valve body, valve seat is provided with through flow hole, valve body inlet communicates with valve seat through flow hole, spool is movably arranged on valve seat, seal by the movement of spool or open through flow hole, it is characterized in that, conical surface is adopted to seal between spool and valve seat, if the diameter of valve seat through flow hole is d, the angle A of described conical surface sealing surface axial cross section meets the following conditions: 12 °≤A≤17 °, cross-sectional height H meets the following conditions: 0.8d≤H≤1.5d.
The high-differential-pressure regulating valve of above structure is adopted to carry out pilot pressure by controlling spool, during adjustment, spool moves, form gap between spool and valve seat, liquid flows through from gap, and there is throttle effect in gap to liquid, the restriction effect of different size is different, control the amplitude that spool moves, the size in gap can be affected, thus impact flows into and the pressure reduction of trickle; The angle A of conical surface sealing surface axial cross section is less than or equal to 17 °, and cross-sectional height H is more than or equal to the diameter d of the valve seat through flow hole of 0.8 times.Spool and valve seat adopt this size relationship to coordinate can obtain higher control sensitivity, and the runner receiving liquid coating layer impact area of simultaneously smaller angle is little, when in liquid with less to the damage of valve sealing surface during more impurity, be conducive to the life-span of improving valve.The angle A of conical surface sealing surface axial cross section is too little, and spool and sealing surface of seat viscous force can be caused too large, and valve is not easily opened, and therefore the angle A of described conical surface sealing surface axial cross section is more than or equal to 12 °.The oversize making being not easy to valve of runner, spool and sealing surface of seat viscous force also can be caused too large, and therefore described conical surface sealing surface axial cross section height H is less than or equal to the diameter d of the valve seat through flow hole of 1.5 times simultaneously.
When the work of valve, the change that liquid flows through pressure in the process of gap can cause the conversion of gas phase and liquid phase, thus causes cavitation, and cavitation can damage spool and valve seat, thus affects using effect and working life.In order to reduce or eliminate this situation, above valve seat, be also provided with valve pocket, described valve pocket is provided with the passage that one end communicates with the through flow hole on valve seat, the other end communicates with the liquid outlet on valve body, and the height B of described passage should be more than or equal to 0.5d.
For ease of regulating, further improvement being done to high-differential-pressure regulating valve structure of the present utility model, it is characterized in that: the height B of passage has been less than or equal to 1.5d.
During use, the valve body of high-differential-pressure regulating valve of the present utility model installs power unit, the actuator of power unit is connected with spool or compresses spool, controls the aperture of spool, valve seat.Described power unit is the general designation controlling the parts that spool moves up and down, and when reality uses, power unit can be the various ways such as cylinder, oil hydraulic cylinder, electric actuator, motor.
When adopting the execution of high-differential-pressure regulating valve of the present utility model, the liquid of entrance has power upwards to spool, the size of strength is relevant to the pressure P of liquid, and the pressure of liquid is relevant with the aperture of spool, valve seat, be therefore applied to the power of spool to control fluid pressure P by controlling power unit.Implementation step is:
(1) the fluid pressure Pk required for setting;
(2) detect the fluid pressure P of entrance, if P>Pk, reduce the power being applied to spool, spool moves, the aperture of spool, valve seat increases, thus reduces P; If P<Pk, increase the power being applied to spool, spool moves down, and the aperture of spool, valve seat reduces, thus improves P;
(3) step (1) and step (2) is repeatedly performed, until P=Pk.
For realizing the control system of above controlling method be, by high-differential-pressure regulating valve, pressure transmitter, comparison operation parts, the circuit of controller and connection all parts, pipeline forms, at the pressure input of the ingress Bonding pressure transmitter of high-differential-pressure regulating valve, the output terminal of pressure transmitter is connected with a signal input part of comparison operation parts, another signal input part input setting pressure value signal of comparison operation parts, the input end of comparison operation parts is connected with the input end of controller, the output terminal of controller connects the power unit of high-differential-pressure regulating valve.Pressure transmitter detects the fluid pressure P of valve inlet, comparison operation parts are inputted after being become the signal of comparison operation parts identification, itself and the liquid pressure value set compare by comparison operation parts, relatively the difference of gained introduces controller, after controller calculates, be applied to the power of spool required for drawing, control power unit and be applied to the power of spool to control the movement of spool.Described comparison operation parts compare P and Pk, execution " P-Pk " computing the device its difference exported, and actual can have various ways, as PLC etc. when using.Described controller has multiple way of realization when practical application, as: PID controller, proportional controller etc.
Embodiment
mode of execution 1.
Fig. 1 is the structural representation of a kind of mode of execution of high-differential-pressure regulating valve of the present utility model.In figure, valve seat 1, spool 2, valve pocket 3 are arranged in valve body 4, the liquid inlet of valve body 4 communicates with the through flow hole 5 of valve seat 1, valve pocket 3 is arranged on above valve seat 1, and through flow hole 6 one end that valve pocket 3 is arranged communicates with the through flow hole 5 on valve seat 1, and the other end communicates with the liquid outlet on valve body 4; Spool 2 is flexibly connected with valve pocket 3, can slide up and down, and the conical surface of spool end coordinates with the conical surface on valve seat 1, when both contact, forms sealing.Cylinder 7 is arranged on valve body 4 top as power unit, and the cylinder bar of cylinder 7 stretches into valve body 4 inside, compresses spool 2.
Fig. 2 to Fig. 5 represents the state of high-differential-pressure regulating valve under spool different heights.In Fig. 2, the spool 2 of high-differential-pressure regulating valve and the conical surface laminating of valve seat 1, the liquid of inflow cannot flow out through passage.
In Fig. 3, spool 2 moves, spool 2 and valve seat 1 disengage, and form gap between the external conical shape face of spool 2 and the inner conical face of valve seat 2, liquid flows through from gap, and there is throttle effect in gap to liquid, thus reduces pressure.
In Fig. 4, spool 2 moves on continuing, and gap increases, and fluid flow strengthens, and pressure reduction effect increases.
In Fig. 5, lift off a seat in the lower end surface of spool 2, now carries out throttling by spool 2 and the passage on valve pocket 3.
As Fig. 2, the diameter of the cross section of the through flow hole 5 that valve seat 1 is arranged is d, and the angle A of described conical surface axial cross section meets the following conditions: 12 °≤A≤17 °.When liquid band impurity, less angle is obvious to the leading role of liquid, less to the impact of sealing surface, contributes to improving the life-span.
As Fig. 3, when spool 2 moves up Δ H, the gap width formed between the external conical shape face of corresponding spool 2 and the inner conical face of valve seat 2 is Δ d, Δ d=tan (A/2) Δ H, therefore the size controlling Δ H can control the width in gap, and then controls restriction effect.
As A=17 °, Δ d=tan8.5 ° of Δ H=0.149 Δ H, Δ H/ Δ d=6.71.
As A=12 °, Δ d=tan6 ° of Δ H=0.105 Δ H, Δ H/ Δ d=9.52.
Can find out, A is less, and the ratio of Δ d and Δ H is less, and the Δ d that same mobile Δ H can cause changes less, and sensitivity is also larger.Although little angle A can obtain larger sensitivity, but the viscous force of spool and the contact surface of valve seat is also larger, when angle A is too small, valve will not easily be opened, 12 ° is can open valve by test and can reach the lowest critical point of better sensitivity, and 17 ° is can ensure to open valve and the maximum critical point that can reach enough sensitivity by test.
As Fig. 2, the height H of the cross section of the conical seal (contact) face that valve seat 1 is arranged meets the following conditions: 0.8d≤H≤1.5d.
Cross-sectional height H affects an other factor of restriction effect, and H is larger, and the length representing gap is longer, and restriction effect is better, but the area of contact of spool, valve seat is also larger, and same viscous force is larger.H=1.5d, is through the maximum value that test can ensure the H normally opened.
H is too short, then can not ensure the restriction effect of this kind of structure, H=0.8d, is through the minimum value that test can ensure restriction effect.
Height B >=the 0.5d of through flow hole 6 on valve seat.
Liquid flows out from gap, sprays in the through flow hole 6 of valve pocket 3, B >=0.5d, makes liquid have enough jet space, thus ensure that on the valve pocket 3 that cavitation mostly occurs in away from sealing surface, improves the life-span of spool, valve seat.
In the present embodiment, through flow hole 6 is the several through holes drilled through along valve pocket 3 radial direction, and this mode realizes simple and convenient, is convenient to make.
B≤1.5d。As shown in Figure 5, when the lower end surface of spool 2 is lifted off a seat after 1, throttling is carried out by spool 2 and the through flow hole 6 on valve pocket 3.B is too high was both unfavorable for restriction effect, was also unfavorable for controlling.The transition point that can reach better effect of test is through during B=1.5d.
mode of execution 2
The present embodiment is the another kind of mode of execution of a kind of high-differential-pressure regulating valve of the present utility model.As Fig. 6, in the present embodiment, power unit is electric actuator, controls moving up and down of spool by controlling electric actuator.
mode of execution 3
The present embodiment uses the pumping pressure regulating system constructed by high-differential-pressure regulating valve of the present utility model.
As shown in Figure 7, the entrance of the delivery outlet of pump 11 with high-differential-pressure regulating valve 12 is connected, at the pressure input of the ingress Bonding pressure transmitter 13 of high-differential-pressure regulating valve, the output terminal of pressure transmitter 13 is connected with a signal input part of comparison operation parts 14, another signal input part of comparison operation parts 14 inputs the control signal of corresponding setup pressure value Pk, the input end of comparison operation parts 14 is connected with the input end of PID controller 15, and the output terminal of PID controller 15 connects the power unit of high-differential-pressure regulating valve 12.Pressure transmitter 13 detects the fluid pressure P of valve inlet, become the signal input comparison operation parts 14 that comparison operation parts can identify, itself and the liquid pressure value Pk set compare by comparison operation parts 14, relatively the difference of gained introduces PID controller 15, after PID controller 15 calculates, be applied to the power of spool 2 required for drawing, control power unit and be applied to the power of spool 2 to control the movement of spool.
The comparison operation parts 14 adopted in the present embodiment are PLC, and the power unit of high-differential-pressure regulating valve is cylinder 7.Corresponding diagram 3 illustrates adjustment process, and the pressure value P k of the pressure value P detected and setting compares, if P>Pk by PLC, then reduce the atmospheric pressure value being applied to cylinder 7, the power Fk that compresses of the cylinder that spool 2 is subject to reduces, and moves, after spool moves under the effect of fluid pressure F, gap between spool valve seat increases, P reduces, and the fluid pressure F that spool 2 is subject to also reduces, as Fk=F, reach equilibrium of forces, spool is stablized; If P<Pk, then increase the atmospheric pressure value being applied to cylinder 7, the power Fk that compresses of the cylinder that spool 2 is subject to increases, move down under the effect compressing power Fk, the gap between spool valve seat reduces, and P increases, the fluid pressure F that spool 2 is subject to also increases, as Fk=F, reach equilibrium of forces, spool is stablized.PID controller control system can carry out the comparison of P and Pk and the adjustment of system pressure, repeatedly until reach the object of P=Pk.
PID controller is easily understood, and does not need the preconditions such as accurate system model in using, and has stronger adaptability.