CN115487395A - Quick-detachable intelligent control proportional electromagnetic valve for breathing machine - Google Patents

Quick-detachable intelligent control proportional electromagnetic valve for breathing machine Download PDF

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Publication number
CN115487395A
CN115487395A CN202210546250.XA CN202210546250A CN115487395A CN 115487395 A CN115487395 A CN 115487395A CN 202210546250 A CN202210546250 A CN 202210546250A CN 115487395 A CN115487395 A CN 115487395A
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China
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parameter
valve
flow
armature
proportional
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Inventor
肖咏
任世勇
田宇鹏
刘帅
计良
鲍会丽
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Beijing Aerospace Xinli Technology Co ltd
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Beijing Aerospace Xinli Technology Co ltd
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Priority to CN202210546250.XA priority Critical patent/CN115487395A/en
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    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
    • A61M16/00—Devices for influencing the respiratory system of patients by gas treatment, e.g. mouth-to-mouth respiration; Tracheal tubes
    • A61M16/20—Valves specially adapted to medical respiratory devices
    • A61M16/201—Controlled valves
    • A61M16/202—Controlled valves electrically actuated
    • A61M16/203—Proportional

Abstract

The invention provides an easily-detachable intelligent control proportional solenoid valve for a breathing machine. According to the proportional electromagnetic valve, the valve sleeve is made of the magnetic isolation material, so that the magnetic isolation effect is realized, and the magnetic flux in the armature is improved; the guide sleeve with the inclined cut structure is arranged, so that thermal expansion installation is not needed, and maintenance is facilitated; in addition, the shell assembly of the proportional solenoid valve is designed to be directly installed with the air inlet and outlet tool through bolts, and the proportional solenoid valve is easy to install and disassemble. Meanwhile, the invention also provides a method for realizing accurate control of the flow of each stage which is subdivided according to different characteristics by adopting a PID closed-loop control mode, thereby optimizing the linearity of a flow curve of a gas medium supplied by the respirator.

Description

Quick-detachable intelligent control proportional electromagnetic valve for breathing machine
Technical Field
The invention relates to the field of precise control of medical instruments, and particularly provides an intelligent control proportional electromagnetic valve device which is high in flow, quick in response, small in structure, simple and easy to disassemble, stable in electromagnetic force and accurate in proportional distribution.
Background
A ventilator is essentially a device used to replace, control or change the normal physiological breathing of a person, increase the lung ventilation, improve the breathing function, and reduce the consumption of the breathing function. As an effective means for artificially replacing the autonomous ventilation function, ventilators have been widely used in three fields:
(1) Respiratory failure due to respiratory diseases: such as chronic obstructive pneumonia, pulmonary infection, and asthma;
(2) Surgery: including respiratory management during anesthesia in large-scale operations, postoperative ventilation support in pediatric surgery, and the like; and
(3) Sleep apnea: such as snoring, and sleep disordered breathing.
The main techniques of the respirator include: ventilation modes, control techniques, measurement techniques, ergonomic and display techniques, and overall core component support techniques. The proportional solenoid valve is a key part on the respirator, and is also regarded as a bright pearl on the crown of the valve. In the process of treating patients with spontaneous dyspnea, doctors need to make different breathing assistance schemes according to the conditions of the patients, and the computer system controls the opening size of the proportional electromagnetic valve according to different volume regulations and requirements of gas release and shows different current amounts according to the different volume regulations and requirements of the proportional electromagnetic valve, so that the flow of inlet and outlet gas, oxygen ratio and other parameters are accurately controlled, and the customized breathing assistance scheme is provided.
The proportional solenoid valve is not a simple piece, with dozens of twenty parts, combined together by electromagnetic force, elastic force, and a precise transmission mechanism. The stroke of swinging and feeding the hair down on the middle valve plate is only a few tenths of millimeters, which is equivalent to the width of several hair wires in parallel. Such a motion trajectory makes it extremely demanding in terms of motion control, reliable sealing, rubber manufacturing accuracy, and degree of pressure resistance of the parts. The proportional electromagnetic valve is an electrically controlled device, and is opened when power is supplied, gas flows from one end of the electromagnetic valve to the other end of the electromagnetic valve, and is closed when power is off, so that the gas flow stops circulating.
In order to ensure the safety of the patient during mechanical ventilation, the ventilator has a relatively strict requirement on the accuracy of flow control, the allowable flow error is usually within 10%, and the parameter is also one of important indexes for measuring the performance of the quality of the ventilator. The inspiratory module of the ventilator is generally responsible for tracking the steady flow as instructed by the master. In the air path of the air suction module, the proportional solenoid valve plays a key role, a large pressure difference exists at two ends of a valve body of the proportional solenoid valve, airflow flows out through a small gap in the valve body to form sonic flow, and the flow rate is determined by the flow area of the proportional solenoid valve. It is generally considered that the flow rate of the proportional solenoid valve and the coil current of the proportional valve are in a linear function relationship, but in practical application, the proportional valve cannot be controlled according to the linear function relationship due to the transient characteristics of the proportional valve, and closed-loop control is adopted.
The proportional solenoid valve is used as a key component of the breathing machine, and has the characteristics of good dynamic characteristic, high control precision, easy integration and the like. In application of a breathing machine, gases with high compressibility are arranged on two sides of a proportional solenoid valve, so that the system has the characteristics of time-varying property, nonlinearity, high disturbance and the like, and an accurate mathematical model is difficult to establish. However, the traditional PID controller usually depends on a determined mathematical model to set parameters, and a set of fixed parameters is used to complete the control task of the system, which makes it difficult to simultaneously satisfy the control requirements of all set output flows. In recent ten years, scholars at home and abroad carry out a great deal of research on pneumatic proportional servo systems, and research results of application control theories, such as adaptive control, fuzzy control, neural network control, variable structure control, robust control and the like, have made certain progress, wherein the fuzzy control is an intelligent control mode, is suitable for controlling systems which are difficult to establish accurate mathematical models and have strong nonlinearity and large lag, has strong robustness for changes of system parameters, has strong anti-interference capability, and can achieve good control effects.
The proportional solenoid valve is based on proportional electromagnet technology, and is a proportional control valve which adopts a proportional electromagnet as an electrical-mechanical conversion element, converts an input current signal into a force and displacement mechanical signal and outputs the force and displacement mechanical signal, thereby continuously and proportionally controlling the flow, pressure and direction of a hydraulic system, and the output flow and pressure can not be influenced by load change, so that the opening degree of the valve can be adjusted by changing the input current. Thereby realizing stepless regulation of the flow. The flow control device has the advantages of simple structure, easiness in processing, convenience in assembly, quick response, high reliability, lower cost and the like, and is very suitable for the application requirement of flow control of a breathing machine system. However, the general proportional solenoid valve has the following limitations in application: and (1) the device cannot adapt to a large-load working condition. When the working pressure is higher or the drift diameter of the valve is larger, a higher pressure difference can be formed between the upstream and the downstream of the valve, and the pressure difference can be overcome by a larger electromagnetic force to open the valve. However, once the valve is opened, the differential pressure force will drop greatly, which causes the force balance relationship of the valve core to be broken, and makes it difficult for the valve armature to maintain at the static throttling position. Therefore, most proportional solenoid valves can only be applied to low load, low flow conditions. (2) The non-linearity and the hysteresis characteristic of the B-H curve of the electromagnetic material can seriously affect the proportional characteristic of the current input and the flow output of the valve, and are not beneficial to the open-loop control of the system.
Particularly, a respirator used in clinical and medical emergency treatment in hospitals needs to use a main control valve group which has the output that the flow can reach 180L/min, has an extremely short response period and performs distribution and mixing functions according to an accurate proportion. For a more advanced ventilator, adequate ventilation and extremely comfortable respiratory support can be provided to the patient according to certain control algorithms, if the above-mentioned preconditions are met.
In addition, for the installation of the proportional solenoid valve in the respirator, bolt connection between the proportional solenoid valve and the air inlet and outlet tool is generally adopted (for example, in patent CN 215780800U). Aiming at the bolt connection at the air inlet and outlet sides, during installation, because a tool surface is larger than the end surface of the proportional solenoid valve, a bolt needs to be installed from one side of a valve seat of the proportional solenoid valve, and part of a bolt hole surface (considering the relation of product size) is blocked by a shell, so that when the installation is needed, after a shell fastening nut of the proportional solenoid valve is disassembled, a shell assembly is removed, after the valve seat is connected with the tool through the bolt, the shell assembly is installed again, and then the fastening nut is installed, so that the installation process is complicated; also, there is little chance that contamination, structure and slight variations in the magnetic field may result from the device.
Meanwhile, in the prior art, in order to realize stable electromagnetic force, a magnetic isolating ring structure is often added between an upper iron core and a lower iron core, so that a magnetic circuit is changed and leads to an armature, the electromagnetic force can be stabilized, and the performance of a proportional electromagnetic valve is improved. However, the proportional solenoid valve is a delicate and tiny component, and the addition of any additional component or part brings certain influence or risk to the manufacturing, assembling difficulty and precision, and is a very important factor to be considered in pursuing the stabilization and customization effect of electromagnetic force, as well as in simplification of the structure, integration of components, or widespread application of existing/original components.
Disclosure of Invention
In order to solve the technical problems of the prior art regarding the requirements of integration, linear flow control and the like of the proportional solenoid valve, the invention provides a proportional solenoid valve device which is used for a breathing machine, easy to detach and intelligent to control. According to the proportional electromagnetic valve, the valve sleeve is made of the magnetic isolation material, so that the magnetic isolation effect is realized, and the magnetic flux in the armature is improved; the guide sleeve with the inclined notch structure is arranged, so that thermal expansion installation is not needed, and maintenance is facilitated; in addition, the shell assembly of the proportional solenoid valve is designed to be directly installed with the air inlet and outlet tool through bolts, and the proportional solenoid valve is easy to install and disassemble. Meanwhile, the invention also provides a method for realizing accurate control of the flow of each stage which is subdivided according to different characteristics by adopting a PID closed-loop control mode, thereby optimizing the linearity of a flow curve of a gas medium supplied by the respirator.
Specifically, in order to achieve the above object, the technical solution of the present invention is:
in a first aspect of the invention, an easily detachable intelligently controlled proportional solenoid valve for a breathing machine is provided, which comprises a valve seat assembly, an armature assembly, a valve sleeve assembly, an adjusting assembly, a coil assembly and an outer assembly. The valve seat assembly is connected with the tool and used for inflow and outflow of gas media, and comprises a valve seat, an air inlet channel and an air outlet channel which are communicated with each other through fluid; the adjusting component applies pre-tightening force to the armature component (through a spring), the coil component surrounds the outside of the valve sleeve component and provides a magnetic field for the armature component, so that the armature component is displaced in the valve sleeve component to control the on-off (communication and blocking) of the air inlet channel and the air outlet channel; the valve sleeve assembly is connected with the valve seat assembly in an abutting mode and is located on one side, far away from the tool, of the valve seat.
Further, the housing assembly comprises three brackets which are positioned at two ends of the coil assembly and assembled on the valve sleeve assembly, a lining plate for pressing the brackets to the valve sleeve assembly and an injection molding housing; the injection molding shell is provided with an extension hole in the valve seat for connecting a bolt hole of the tool, and the extension hole is used for integrally fastening the shell to the tool by using a long bolt; and the circuit board in the coil assembly is positioned in the injection molding shell and used for controlling the current of the coil in the coil assembly. The liner plate presses the support to the valve sleeve assembly (where the valve sleeve is in sealed connection with the valve seat) and fastens the liner plate and the valve seat through bolts, so that the support is fixed. The support is made of magnetic conductive materials. The injection molding shell is integrally formed by injection molding, plays a role in protecting the interior of the proportional solenoid valve, forms an integral device, is convenient to match with various target breathing machines, and is easy to install and disassemble.
Preferably, the shell of moulding plastics with the valve seat subassembly forms the whole that the main part is the cuboid, except that the protrusion sets up the off-plane of circuit board, three supports are located respectively other three sides of the shell of moulding plastics are as inside support.
Preferably, the valve housing assembly comprises a valve housing, an adjustment seat and a sealing member (preferably, a sealing ring) for sealing connection with the valve seat assembly; the valve sleeve and the adjusting seat are welded into a whole, are respectively matched with the armature component and the adjusting component and respectively provide moving guide for the armature component and the adjusting component; the valve sleeve is made of a magnetic isolation material. The valve sleeve can realize the effect of the magnetism isolating ring, improves the magnetic flux in the armature, does not need to design the magnetism isolating ring, and has simpler structure. Preferably, the length of the valve sleeve on the side away from the valve seat in the coil direction exceeds the distal end face of the armature (the side away from the valve seat) but does not exceed the distal end of the coil, and the thickness of the valve sleeve (the guide portion accommodating the armature) is preferably between 0.5 and 1.5mm, and too thin or too thick results in a reduction in the electromagnetic force.
Preferably, the valve seat assembly further comprises an air inlet sealing ring and an air outlet sealing ring, which respectively realize the sealing of the air inlet channel and the air outlet channel.
Preferably, the armature assembly includes an armature, a seal block, and a guide sleeve. The armature pushes the sealing block to reciprocate under the action of a magnetic field of the coil assembly and a spring of the adjusting assembly, so that the opening and closing control (and flow control) of the air inlet channel by the sealing block is realized; the left and right sides of the armature are provided with two through holes for balancing the air pressure of the adjusting component side and the air pressure of the valve seat side; the guide sleeve is arranged in a corresponding groove on the outer surface of the armature and is used for abutting against/contacting the valve sleeve, when the armature is under the action of magnetic field force, the armature overcomes the friction between the guide sleeve and the valve sleeve in the valve sleeve to perform guide movement, and the guide sleeve is of a cylindrical surface structure with an oblique fracture. Based on the oblique fracture, the guide sleeve does not need to be thermally expanded during installation, can be directly clamped and installed, and is convenient to maintain.
Preferably, the adjustment assembly includes a spring, an adjustment rod and a seal. Two ends of the spring respectively abut against an adjusting rod and a spring groove reserved in the armature; the adjusting rod is connected with the adjusting seat through threads and sealed through the sealing element (preferably a sealing ring); the position of the adjusting rod is adjusted through the screw thread, so that the pre-tightening force of the spring connected with the adjusting rod (the other end) on the armature is adjusted.
Preferably, the coil assembly includes a bobbin, a coil, and a circuit board. The circuit board is arranged in the protruding end of the injection molding shell and used for controlling the current of the coil; the coil is arranged around the coil framework to provide a required magnetic field for the armature. And the circuit board is written with a control algorithm and used for controlling the current of the coil and optimizing the linearity of a flow curve. The circuit board can also modify the program according to the requirements of different working modes, so that the upgrading and the transformation of products are facilitated, and the expansibility of the proportional solenoid valve is increased.
In addition, the invention also provides an intelligent precise control method of the proportional electromagnetic valve in a second aspect. When the proportional solenoid valve works, due to the combined action of various factors such as the hysteresis effect of a magnetic material, the pressure of a gas medium, the spring force, the friction force and the like, the relation curve between the gas flow output by the proportional solenoid valve and the input current is continuously changed. For example, fig. 5 shows a flow rate curve when the current gradually decreases from 0A to 0A after reaching a maximum. Wherein, the electromagnet (armature) in the proportional electromagnetic valve needs a certain current to open (starting current), and the slope of the flow curve in the early stage after opening is small (Q) 0 To Q 1 ) The slope in the middle stage is large (Q) 1 To Q 2 ) The slope at the later stage is smaller (Q) 2 To Q 3 ) And the flow curve of decreasing current versus increasing current produces hysteresis. In addition, in the case of using a current larger than the starting current as the starting current, different starting currents will also produce different flow curves. These characteristics ultimately cause a certain (uncertain/stable) error between the actually obtained flow and the set flow value corresponding to the set current, so that the output flow is not accurate enough.
Aiming at the technical problem, the invention also provides an intelligent precise control method of the proportional solenoid valve, which adopts a PID closed-loop control mode to realize precise control of flow. And on the basis of the actual flow value fed back by the system, the current of the proportional solenoid valve is controlled in real time by adopting a PID algorithm, so that the accurate output of the flow of the proportional solenoid valve is realized.
Specifically, an intelligent accurate control method for a proportional solenoid valve comprises the following steps:
(1) Dividing the flow Q into a plurality of intervals according to the slope characteristic of the flow curve of the proportional solenoid valve and the range of the actual flow Qc and the flow change delta Q; each interval has a group of PID control parameters; wherein the flow rate change Δ Q is a difference between the target flow rate Qt and the actual flow rate Qc;
(2) Debugging the PID parameters of each interval aiming at the flow regulation range of each interval, and determining the PID parameters of each interval;
(3) And according to the PID parameters determined in each interval, storing the PID parameters into a storage module, and writing a control program into a chip of the circuit board. When the proportional solenoid valve is used, the program selects a corresponding interval and automatically calls a matched PID parameter based on the detected actual flow Qc and the flow difference value delta Q, so that a corresponding current signal is output to realize the real-time flow control.
Preferably, the PID parameter debugging is composed of three parts of proportional regulation, integral regulation and differential regulation; wherein the PID parameter comprises a proportional parameter K p Integral parameter K i And a differential parameter K d 。
Preferably, in the step (3), the output current signal u (t) is obtained by calculating according to the following formula:
u(t)＝K p *ΔQ(t)+K i *∫ΔQ(t)dt+K d *dΔQ(t)/dt
wherein, the first and the second end of the pipe are connected with each other,
t is time;
u (t) is an output current signal at time t;
K p is a proportional parameter;
K i is an integral parameter;
K d is a differential parameter; and is provided with
Δ Q (t) is the difference between the target flow rate Qt and the detected actual flow rate Qc at time t.
Further, the debugging of the PID parameters in the step (2) is generally realized by the following steps:
a. determining a scaling parameter K p : first order K i ＝0、K d =0, make PID pure scale adjustment; subsequently, the proportional parameter is gradually increased from 0 until the system (output signal of the PID control system) oscillates, and an oscillation proportional parameter K is obtained at the time p1 (ii) a From the oscillation ratio parameter K p1 Gradually, graduallyReducing until the system oscillation disappears, and obtaining the proportion parameter K p2 (ii) a Thereby, the proportional parameter K is set p Is K p2 60% -70%;
b. determining an integral parameter K i : proportional parameter K p After the determination, a larger initial value integral parameter K is set i0 From K by i0 Gradually decrease until the system oscillates (K) i1 ) Gradually increasing until the system oscillation disappears, and obtaining an integral parameter K i2 (ii) a Thus, the integral parameter K of PID is set i Is K i2 150% -180%;
c. determining a differential parameter K d : at a proportional parameter K p And integral parameter K i After setting, the differential parameter K d Can be set to 0; or, optionally, at a scaling parameter K p And integral parameter K i After setting, the differential parameter is gradually increased from 0 to disappearance of oscillation, and the differential parameter K is obtained d1 And the differential parameter K is determined d Is set to K d1 30% of the total.
Further, the method further comprises a step (2') between the step (2) and the step (3), of: repeating the steps (1) to (2) to obtain updated PID parameters.
In addition, the third aspect of the present invention further provides an intelligent precise control system for a proportional solenoid valve, including: a flow sensor for acquiring a current/actual flow rate Qc; the acquisition module is used for setting a target flow Qt; the calculating module is used for calculating a difference value delta Q according to the target flow Qt and the actual flow Qc; the PID parameter storage and calling module is used for storing PID parameters regulated by the PID parameters and calling matched PID parameters according to the actual flow Qc and the difference value delta Q; and the control module is used for controlling the current of the proportional electromagnetic valve through a PID algorithm according to the currently called PID parameter until the actual flow value fed back by the flow sensor is equal to the set target value Qt.
On the basis of the scheme, the quick-detachable intelligent control proportion electromagnetic valve for the breathing machine provided by the invention has the following advantages:
the shell assembly of the proportional solenoid valve provided by the invention can be arranged on an air inlet and outlet tool under the condition of not disassembling the proportional solenoid valve.
The guide sleeve of the armature is of an inclined opening structure, does not need thermal expansion during installation, can be directly installed and is convenient to maintain.
The valve sleeve is made of a magnetism isolating material, the effect of a magnetism isolating ring can be achieved through the valve sleeve, the magnetic flux in the armature is improved, the magnetism isolating ring does not need to be designed, and the structure is simpler;
the conventional flow curve of the proportional solenoid valve is nonlinear, and the linearity of the flow curve of the proportional solenoid valve is improved by adding an intelligent control chip and adjusting the current change under different duty ratios. The circuit board can modify the procedure according to the needs of different working modes in the proportional solenoid valve, and the upgrading of the product of being convenient for increases proportional solenoid valve expansibility.
Drawings
Fig. 1 is a structural sectional view of an easily detachable intelligent control proportional electromagnetic valve for a breathing machine of the invention.
FIG. 2 is a schematic axial view of an un-injection molded housing of a readily detachable intelligent control proportional solenoid valve for a ventilator according to the present invention.
FIG. 3 is a schematic axial view of a product of the easily detachable intelligent control proportional solenoid valve for a breathing machine according to the present invention after injection molding of the housing.
Fig. 4 is an external structural schematic diagram of an armature assembly of an easily detachable intelligent control proportional solenoid valve for a breathing machine according to the present invention.
FIG. 5 is a plot of proportional solenoid flow versus current.
FIG. 6 is a schematic diagram of a method of PID controlling the flow of a proportional solenoid valve.
Fig. 7 is a flow chart of a system and method for real-time flow control according to the method of the present invention.
Detailed Description
The present invention will be further described with reference to the accompanying drawings.
The easy-to-detach intelligent control proportional solenoid valve for the breathing machine as shown in fig. 1-4 is composed of a valve seat assembly, an armature assembly, a valve sleeve assembly, an adjusting assembly, a coil assembly and an outer casing assembly.
Specifically, the valve seat assembly includes a valve seat 11, an outlet seal ring 12 and an inlet seal ring 13, which respectively seal an outlet passage (four outlets in the top outer circle as shown in fig. 2) and an inlet passage (one inlet passage in the top center as shown in fig. 2), and the valve seat assembly is used for the inflow and outflow of the gas medium. The valve seat 11 is provided with an air inlet channel and four air outlet channels, and the two channels are communicated with each other through fluid. As shown in fig. 1, the inlet port of the inlet passage in the valve seat chamber is disposed opposite a sealing block 22 in the armature assembly, the sealing block 22 being used to control communication and blocking of the inlet port with the valve seat chamber (outlet passage). Meanwhile, the valve seat 11 is further provided with four bolt holes (top surface outermost periphery) for fitting to a target tool by means of bolts.
The armature 21, the sealing block 22 and the guide sleeve 23 constitute an armature assembly. The armature 21 moves up and down in the cavity defined by the valve seat assembly under the action of the magnetic field provided by the coil assembly and the longitudinal (as shown in the orientation in fig. 1) force of the spring 41 of the adjusting assembly, so as to drive the sealing block 22 (fixedly connected), and the sealing block 22 and the valve seat 11 (the air inlet in the cavity) can be opened and closed, so as to control the outlet air flow. The left side and the right side of the armature 21 are provided with two through holes for controlling the balance of air pressure in the valve. As shown in fig. 4, the outer structure of the armature assembly is schematically illustrated, wherein the guide sleeves 23 (two) are cylindrical structures with oblique fractures, and can be directly slightly deformed and clamped into a clamping groove formed on the outer surface of the armature, so as to facilitate installation and maintenance. The guide sleeve 23 is the interface of the armature assembly with the valve sleeve 31 for frictional movement of the armature 21 within the cavity defined by the valve sleeve 31.
The valve sleeve 31 is welded with the adjusting seat 32 as a whole, and forms a valve sleeve assembly together with the sealing ring 33. When the proportional solenoid valve works, the armature component moves up and down in the valve sleeve component, and friction exists between the guide sleeve 23 and the valve sleeve 31.
The spring 41, the adjusting rod 42 and the sealing ring 43 constitute an adjusting assembly. The adjusting rod 42 is connected with the adjusting seat 32 through threads and sealed through a sealing ring 43, and the performance of the proportional solenoid valve can be controlled by adjusting the pretightening force of a spring through adjusting the position of the adjusting rod 42.
The coil bobbin 51, the coil 52, and the circuit board 53 collectively constitute a coil assembly. When the coil is energized, a magnetic field is generated for controlling the displacement of the armature 21, and a control algorithm is written on the circuit board for controlling the current of the coil and optimizing the linearity of a flow curve.
The bracket 61, the bracket 62, the bracket 63, the liner plate 64 and the injection molded housing 65 constitute a housing assembly. Wherein, the two ends of the bracket 61, the bracket 62 and the bracket 63 are respectively positioned at the two ends of the coil assembly and abut against the lower surface of the valve sleeve 31 (where the valve seat 11 is hermetically connected), the lining plate 64 is fastened with the valve seat 11 through bolts, and the brackets 61-63 (and the valve sleeve 31) positioned between the two are pressed tightly; the proportional solenoid valve case 65 is formed by injection molding, and plays a role in protecting the proportional solenoid valve. Preferably, as shown in fig. 2, the lining plate 64 has holes at four corners corresponding to the four tooling mounting holes of the valve seat 11, and the connecting line of the holes of the lining plate 64 and the mounting holes of the valve seat 11 forms an extended hole in the injection mold 65 for bolt fastening. Preferably, two optional diagonal holes are used to fasten the lining plate 64 and the brackets 61-63 to the valve seat 11 (by short bolts), and the proportional solenoid valve obtained after injection molding is installed to the target tool through the other two diagonal holes (long bolts).
Specifically, the working principle of the proportional electromagnetic valve provided by the invention is as follows:
referring to fig. 1, when the proportional solenoid valve is not energized, the proportional solenoid valve is in a normally closed state, the spring 41 has a certain pre-tightening force, the armature 21 pushes the sealing block 22 against the air inlet of the valve seat 11, and the sealing block 22 blocks the inflow of the gas medium. When the coil 52 is energized, the magnetic circuit generated by the magnetic isolation function of the valve sleeve 31 enters the armature 21 from the adjusting seat 32 to generate electromagnetic force, the armature 21 is moved downward by the electromagnetic force overcoming the pressure of the spring 41 and the friction force between the guide sleeve 23 and the valve sleeve 31, the valve (air inlet) is opened, and the medium flows in. The displacement of the armature 21 changes with the change in the coil current, thereby controlling the flow rate of the proportional solenoid valve. The program preset in the circuit board 53 can control the change of the actual current in the coil to modify the flow curve of the medium, so that the flow curve can be changed linearly, thereby realizing the proportional control of the medium flow.
Referring to fig. 2, round holes are dug in the brackets 61 to 63, so that the weight is reduced, and the material flows sufficiently during the injection molding of the shell, so that the strength of the shell is improved. Circuit board can be modified the procedure according to the needs of different working modes among the proportional solenoid valve, and the upgrading of the product of being convenient for is reformed transform, increases proportional solenoid valve expansibility.
In addition, the invention also provides an intelligent and accurate control method of the proportional solenoid valve. The control principle is shown in fig. 6. The PID controller consists of three parts of proportional regulation, integral regulation and differential regulation. The proportional adjustment adjusts the output according to the magnitude of the deviation, the integral adjustment performs integral accumulation according to the deviation to adjust the output, and the differential adjustment adjusts the output according to the differential of the deviation. The expression of the PID algorithm is:
u(t)＝K p *ΔQ(t)+K i *∫ΔQ(t)dt+K d *dΔQ(t)/dt
wherein:
t: time of day
u (t): output current signal of t-time PID controller
Kp: a ratio parameter;
ki: an integration parameter;
kd: a differential parameter;
Δ Q (t): t is the difference between the target flow rate Qt and the actual flow rate Qc.
Specifically, the whole intelligent accurate debugging control process of the proportional solenoid valve is as follows:
(1) The flow rate is divided into several groups of intervals (three groups as shown in fig. 5) according to the flow rate curve characteristic (slope) of the proportional solenoid valve and according to the ranges of the actual flow rate Qc and the flow rate variation/difference value Δ Q, each group corresponding to one group of PID control parameters.
(2) And respectively debugging PID control parameters for each group of flow regulation range.
(3) And storing each group of PID parameters obtained by debugging into a storage module, and writing a control program into a chip. When the proportional electromagnetic valve is used, the program can automatically call matched PID parameters according to the actual flow Qc and the flow difference value delta Q to control the flow and output current signals.
In the step (1), according to the characteristics of a flow-current curve of the proportional solenoid valve, the flow of the proportional solenoid valve is divided into three sections, namely Q0, Q1, Q2 and Q3, wherein when the flow Qc is less than Q1, the proportional solenoid valve is in a starting stage of the proportional solenoid valve, the slope of the flow-current curve is small at the moment, the flow rises gently, when the flow Q1 is less than Qc and less than Q2, the slope of the flow-current curve is large, the flow rises rapidly, when the flow Q2 is less than Qc and less than Q3, the stroke of the proportional solenoid valve is maximum, the current is continuously increased at the moment, and the flow can be kept unchanged.
If necessary, the flow range can be divided into more intervals, and the change of different intervals corresponds to different parameters so as to adapt to the quick response of the flow.
In the step (2), the general steps of the parameter adjusting process are as follows:
a. determining a proportional parameter Kp: when determining the proportional parameter Kp, the integral term and the derivative term of PID are first removed, and generally Ki =0 and Kd =0 are set so that PID is purely proportional. Gradually increasing the proportional parameter Kp from 0 until the system (the output current signal of the PID regulating system) oscillates; and conversely, the proportional parameter Kp at the moment is gradually reduced until the system oscillation disappears, the proportional parameter Kp at the moment is recorded, and the proportional parameter Kp of the PID is set to be 60% -70% of the current value. And completing debugging of the proportional parameter Kp.
b. After determining the integral parameter Ki and the proportional parameter Kp, setting an initial value of a larger integral parameter Ki, then gradually reducing Ki until the system oscillates, and then gradually increasing Ki in reverse until the system oscillates and disappears. Ki at this time is recorded, and the integral parameter Ki of PID is set to 150% to 180% of the current value. The integration parameter Ki is adjusted.
c. The integral parameter Kd is determined as 0 without setting it. If the setting is required, the integral parameter Kd is gradually increased from 0 until the oscillation disappears, and finally Kd takes the current 30%.
The control flow of the control system when the proportional solenoid valve is used is as follows:
FIG. 7 is a flow control system and flow chart for use with a proportional solenoid valve. The module M1 is a flow sensor for obtaining an actual flow Qc (i.e., a current flow), the module M2 is an obtaining module for obtaining a set target flow value Qt, the module M3 is a calculating module for calculating a difference Δ Q between the target flow Qt and the current flow Qc, the module M4 is a PID parameter storage module for storing PID parameters between the respective zones obtained by PID tuning, when the flow is adjusted, the corresponding PID parameter is called according to the values of Qc and Qt and is transmitted to the module M5, the module M5 is a control module for controlling the proportional solenoid valve current according to the current PID parameter by a PID algorithm until the flow value fed back by the module M1 is equal to the set target value Qt.
It should be understood that the directional indications "left", "right", "up", "down", etc. described herein are divided in the direction of the device itself as exemplified in the figures. It should be understood that the terms left, right, up, down, etc. in the embodiments of the present invention are used interchangeably and are not intended to limit the spirit of the embodiments.
The above-mentioned examples are only for describing the preferred embodiments of the present invention, and do not limit the scope of the present invention, and any simple modifications, equivalent changes and modifications made to the technical solution of the present invention without departing from the design concept of the present invention still fall within the scope of the present invention.

Claims (10)

1. An easily-detachable intelligent control proportional electromagnetic valve for a breathing machine is characterized by comprising a valve seat assembly, an armature assembly, a valve sleeve assembly, an adjusting assembly, a coil assembly and an outer assembly;
the valve seat assembly is connected with the tool and used for inflow and outflow of gas media, and comprises a valve seat, an air inlet channel and an air outlet channel which are communicated by fluid; the adjusting component applies a certain pretightening force to the armature component, the coil component surrounds the outside of the valve sleeve component and provides a magnetic field for the armature component, so that the armature component is displaced in the valve sleeve component to control the on-off of the air inlet channel and the air outlet channel; the valve sleeve component is connected against one side, far away from the tool, of the valve seat component;
the shell assembly comprises three brackets, a lining plate and an injection molding shell, wherein the three brackets are positioned at two ends of the coil assembly and assembled on the valve sleeve assembly; the injection molding shell is provided with an extension hole in the valve seat for connecting a bolt hole of the tool, and the extension hole is used for integrally fastening the shell to the tool by using a long bolt; and the circuit board in the coil assembly is positioned in the injection molding shell and is used for controlling the current of the coil in the coil assembly.
2. The easy-to-detach intelligent control proportional solenoid valve for a breathing machine according to claim 1, wherein the injection molding shell and the valve seat assembly form a whole body with a cuboid main body, and the three supports are respectively located on three sides of the other side of the injection molding shell as internal supports except for a face convexly provided with the circuit board.
3. The readily removable intelligent control proportional solenoid valve for a breathing machine according to claim 1 or 2, wherein the valve housing assembly comprises a valve housing, an adjustment seat and a first seal (33) for making a sealing connection with the valve seat assembly; the valve sleeve and the adjusting seat are welded into a whole, are respectively matched with the armature component and the adjusting component and respectively provide moving guide for the armature component and the adjusting component; the valve sleeve is made of a magnetic isolating material, and the thickness of the guide part of the valve sleeve is preferably 0.5-1.5mm.
4. The easy-to-disassemble intelligent control proportional solenoid valve for a breathing machine according to any one of claims 1-3, wherein the valve seat assembly further comprises an inlet sealing ring and an outlet sealing ring; the armature component comprises an armature, a sealing block and a guide sleeve; the armature pushes the sealing block to reciprocate under the action of the magnetic field of the coil assembly and the spring of the adjusting assembly, so that the opening and closing and flow control of the sealing block to the air inlet of the air inlet channel are realized; the left and right parts of the armature are provided with two through holes for balancing the air pressure at the adjusting component side and the valve seat side; the guide sleeve is arranged in a corresponding groove on the outer surface of the armature and is used for abutting against the valve sleeve assembly, when the armature is under the action of magnetic field force, the armature overcomes the friction between the guide sleeve and the valve sleeve in the valve sleeve assembly to move, and the guide sleeve is of a cylindrical surface structure with a diagonal opening.
5. The easy-to-disassemble intelligent control proportional solenoid valve for a breathing machine according to any one of claims 1-4, wherein the adjusting assembly comprises a spring, an adjusting rod and a second sealing member (43); two ends of the spring respectively abut against the adjusting rod and a spring groove reserved in the armature; the adjusting rod is connected with the adjusting seat through threads, and sealing is achieved through the second sealing piece (43); the position of the adjusting rod is adjusted through the threads, so that the pretightening force of the spring connected with the adjusting rod on the armature is adjusted; the coil assembly comprises a coil framework, a coil and a circuit board; the circuit board is arranged in the protruding end of the injection molding shell and used for controlling the current of the coil; the coil is arranged around the coil framework to provide a required magnetic field for the armature.
6. An intelligent accurate control method of a proportional solenoid valve is characterized by comprising the following steps:
(1) Dividing the flow Q into a plurality of intervals according to the slope characteristic of the flow curve of the proportional solenoid valve and the range of the actual flow Qc and the flow change delta Q; wherein the flow change Δ Q is a difference between the target flow Qt and the actual flow Qc;
(2) Debugging the PID parameters of each interval according to the flow regulation range of each interval, and determining the PID parameters of each interval;
(3) And automatically calling the matched PID parameters based on the detected actual flow Qc and the flow difference value delta Q according to the PID parameters determined in each interval, thereby outputting corresponding current signals to realize flow control.
7. The intelligent precise control method of the proportional solenoid valve according to claim 6, wherein the PID parameter debugging consists of three parts, namely proportional regulation, integral regulation and differential regulation; wherein the PID parameter comprises a proportional parameter K p Integral parameter K i And a differential parameter K d 。
8. The intelligent precise control method of the proportional solenoid valve as claimed in claim 6 or 7, wherein in the step (3), the output current signal is obtained by calculating according to the following formula:
u(t)＝K p *ΔQ(t)+K i *∫ΔQ(t)dt+K d *dΔQ(t)/dt
wherein, the first and the second end of the pipe are connected with each other,
t is time;
u (t) is an output current signal;
K p is a proportional parameter;
K i is an integral parameter;
K d is a differential parameter; and is
Δ Q (t) is the difference between the target flow rate Qt and the detected actual flow rate Qc.
9. The intelligent precise control method for the proportional solenoid valve according to any one of claims 6-8, wherein the PID parameter debugging in the step (2) is realized by the following steps:
a. determining a scaling parameter K p : first, set K i ＝0、K d =0, make PID pure scale adjustment; then, the proportional parameter is gradually increased from 0 until the system oscillates, and the oscillation proportional parameter K is obtained at the moment p1 (ii) a Secondary oscillation proportional parameter K p1 Gradually reducing until the system oscillation disappears, and obtaining the proportion parameter K at the moment p2 (ii) a Setting a proportional parameter K p Is K p2 60% -70%;
b. determining an integral parameter K i : proportional parameter K p After determination, a larger initial product is setSub-parameter K i0 From K by i0 Gradually reducing until the system generates oscillation, and gradually increasing until the system oscillation disappears, and then obtaining an integral parameter K i2 (ii) a Setting an integral parameter K i Is K i2 150% -180%;
c. determining a differential parameter K d : differential parameter K d Can be set to 0; or, gradually increasing the differential parameter from 0 to disappearance of oscillation, and obtaining the differential parameter K d1 And the differential parameter K is determined d Is set to K d1 30% of the total.
10. The utility model provides an accurate control system of intelligence of proportional solenoid valve which characterized in that, real-time system includes:
a flow sensor for acquiring an actual flow rate Qc;
the acquisition module is used for setting a target flow Qt;
the calculating module is used for calculating a flow difference value delta Q according to the target flow Qt and the actual flow Qc;
the PID parameter storage and calling module is used for storing PID parameters regulated by the PID parameters and calling matched PID parameters according to the actual flow Qc and the flow difference value delta Q; and
and the control module is used for carrying out current control on the proportional electromagnetic valve through a PID algorithm according to the called PID parameter until the actual flow value fed back by the flow sensor is equal to the set target flow Qt.
CN202210546250.XA 2022-05-19 2022-05-19 Quick-detachable intelligent control proportional electromagnetic valve for breathing machine Pending CN115487395A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202210546250.XA CN115487395A (en) 2022-05-19 2022-05-19 Quick-detachable intelligent control proportional electromagnetic valve for breathing machine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202210546250.XA CN115487395A (en) 2022-05-19 2022-05-19 Quick-detachable intelligent control proportional electromagnetic valve for breathing machine

Publications (1)

Publication Number Publication Date
CN115487395A true CN115487395A (en) 2022-12-20

Family

ID=84465309

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202210546250.XA Pending CN115487395A (en) 2022-05-19 2022-05-19 Quick-detachable intelligent control proportional electromagnetic valve for breathing machine

Country Status (1)

Country Link
CN (1) CN115487395A (en)

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