CN212028721U - Pilot-operated proportional flow valve with position feedback function - Google Patents
Pilot-operated proportional flow valve with position feedback function Download PDFInfo
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- CN212028721U CN212028721U CN202020701576.1U CN202020701576U CN212028721U CN 212028721 U CN212028721 U CN 212028721U CN 202020701576 U CN202020701576 U CN 202020701576U CN 212028721 U CN212028721 U CN 212028721U
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Abstract
The utility model relates to a pilot-operated proportional flow valve with position feedback function, which comprises a pilot valve and a main valve which are communicated with each other, wherein the pilot valve comprises a controller and a pilot valve module; the main valve comprises a valve body, a valve core, a left end cover, a right end cover and a spring; a pilot valve control port of the pilot valve is communicated with a main valve control port of a main valve, the main valve control port of the main valve is communicated with a right control cavity of the main valve, and a displacement sensor for measuring the displacement of a valve core is arranged in the main valve; the pressure of a pilot valve control port of the pilot valve is in a first nonlinear characteristic relation with an input signal, the pressure of a main valve control port of the main valve is in a linear relation with the opening degree of a valve port of the main valve, and the opening degree of the valve port of the main valve is in a second nonlinear characteristic relation with the output gas flow; and correcting the output gas flow and the input signal to form a linear relation, and solidifying the pressure value of the control port of the intermediate variable pilot valve into the controller. The advantages are that: reasonable structure, good stability and high response speed, and is suitable for controlling the gas flow.
Description
Technical Field
The utility model belongs to the technical field of gas flow control technique and specifically relates to indicate a take guide's formula proportional flow valve of position feedback function.
Background
The flow rate of the fluids (gas and liquid), when the external conditions (pressure and temperature, etc.) are constant, is generally related to the size of the cross section of the space through which the fluid flows. For a specific flow valve, the opening degree of the valve port is controlled to realize the output of a flow value with a required size.
By proportional flow valve is meant that the flow output of a control valve is linear with the value of the input signal (current or voltage) applied to it. The pilot control valve is a valve in which the movement of the spool of the main valve is controlled by the output pressure of the pilot valve.
The pilot valve is generally a microminiature direct-acting proportional pressure valve. The direct-acting proportional pressure valve generally comprises a control circuit, an electromechanical converter and a control valve core. The control mechanism is that input electric signal (voltage/current) is input to a control circuit, after the signal is amplified, the signal is input to an electromechanical converter to output mechanical displacement, and the displacement forms the opening degree of a valve port to control the output pressure value. This pressure value is typically proportional to the input electrical signal.
The control pressure of pilot valve is led into control cavity in main valve to control the movement of main valve core, and the valve core can output a displacement (valve port opening) which is linear relation with pressure by means of valve core spring system.
For liquid, the opening degree of the valve port and the flow rate can be approximately considered as proportional relation in a certain flow rate range. Therefore, the hydraulic control device has wide application in the field of hydraulic control and good effect.
However, due to the large difference in physical properties of gases and liquids, liquids are generally considered incompressible fluids, whereas gases, obviously, are compressible fluids. The flow rate of gas flowing through the valve port is in a nonlinear relationship with the opening degree of the valve port. Thus, the flow of gas cannot be proportional to the input signal.
In the control system, the process of feeding back the target output quantity to the front end to compare with the input quantity, thereby allowing the system to automatically adapt to the output target value is called feedback control. In fluid control valves, feedback techniques are widely used; the position feedback is to feed the output displacement value of the main valve core back to the front end controller to be compared with a target control value. The controller then further issues control commands to correct the deviation in the actual output quantity. Compared with open-loop control, a closed-loop control system with negative feedback function has great improvement in both system stability and system response rapidity.
Disclosure of Invention
The utility model aims to solve the technical problem that to prior art's current situation, provide rational in infrastructure, be applicable to gas flow control, stability is good, a take guide's formula proportional flow valve of position feedback function that response speed is fast.
The utility model provides a technical scheme that above-mentioned technical problem adopted does:
a pilot type proportional flow valve with a position feedback function comprises a pilot valve and a main valve which are communicated, wherein the pilot valve is provided with a pilot valve air inlet, a pilot valve pressure relief opening and a pilot valve control opening, and comprises a controller and a pilot valve module; the main valve is provided with a main valve air supply port, a main valve exhaust port, a main valve control port, a working port and a pilot valve interface, and comprises a valve body, a valve core, a left end cover, a right end cover and a spring, wherein the spring is arranged between the valve core and the left end cover; a pilot valve control port of the pilot valve is communicated with a main valve control port of a main valve, the main valve control port of the main valve is communicated with a right control cavity of the main valve, a displacement sensor for measuring the displacement of a valve core is arranged in the main valve, and the displacement sensor is connected with a controller in a feedback way;
the pressure of a pilot valve control port of the pilot valve is in a first nonlinear characteristic relation with an input signal, the pressure of a main valve control port of the main valve is in a linear relation with the opening degree of a valve port of the main valve, and the opening degree of the valve port of the main valve is in a second nonlinear characteristic relation with the output gas flow; through laboratory tests, the output gas flow and the input signal are corrected to form a linear relation, and the pressure value of the control port of the intermediate variable pilot valve is solidified into the controller.
The optimized technical measures further comprise:
foretell pilot valve module is including the solenoid valve that admits air, exhaust solenoid valve, pressure sensor and gas circuit bottom plate, the controller with the solenoid valve that admits air, exhaust solenoid valve control is connected, pressure sensor feedback is connected in the controller, the solenoid valve that admits air sets up between pilot valve air inlet and pilot valve control mouth, exhaust solenoid valve sets up between pilot valve pressure release mouth and pilot valve control mouth.
The controller comprises a processor, an M/A analog-to-digital converter, an input/output interface circuit, a display circuit, a power supply and an electromagnetic valve driving circuit.
The left end of the right end cover is provided with a convex block, and a right control cavity is formed between the periphery of the convex block and the inner wall of the valve body.
The middle part of the valve core is provided with a groove.
The displacement sensor comprises a fixed part and a movable induction part, wherein the fixed part is arranged on the left end cover, and the movable induction part is fixed at the left end of the valve core.
And a sealing ring is arranged between the right end cover and the valve body.
The right end cover and the valve body are fixed through screws.
And an outer housing is arranged outside the controller and the pilot valve module.
The utility model discloses a take guide formula proportional flow valve of position feedback function, rational in infrastructure, constitute by pilot valve and main valve, be first nonlinear characteristic relation between the pressure of the pilot valve control mouth of pilot valve and the input signal, be linear relation between the pressure of the main valve control mouth of main valve and the valve port aperture of main valve, be second nonlinear characteristic relation between the valve port aperture of main valve and the output gas flow; through laboratory tests, the output gas flow and the input signal are corrected to form a linear relation, and the pressure value of the control port of the intermediate variable pilot valve is solidified into a controller; therefore, the linear relation between the flow of the main valve and an input signal is realized, the proportional control of the flow is realized, the valve is suitable for a gas flow environment, a displacement sensor for measuring the displacement of the valve core is arranged in the main valve, the displacement of the valve core is measured through the displacement sensor, and the closed loop feedback of the position of the valve core is formed, so that the flow is accurately controlled, the stability of flow output is improved, and the response speed is improved.
Drawings
Fig. 1 is a schematic structural diagram of the present invention;
FIG. 2 is a schematic structural view of the pilot valve of FIG. 1 with the outer casing removed;
FIG. 3 is a bottom view of the pilot valve of FIG. 1;
fig. 4 is a control schematic diagram of the pilot valve of the present invention;
FIG. 5 is a schematic diagram of the controller of FIG. 4;
FIG. 6 is a schematic view of the main valve of the present invention;
fig. 7 is a top view of the main valve of the present invention;
fig. 8 is a control schematic diagram of the proportional flow valve of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the following embodiments.
As shown in fig. 1 to 8, the structure of the present invention is schematically illustrated,
wherein the reference numerals are: a first nonlinear characteristic relationship L1, a linear relationship L2, a second nonlinear characteristic relationship L3, a pilot valve air inlet P1, a pilot valve pressure relief port R1, a pilot valve control port K1, a main valve air supply port P2, a main valve exhaust port R2, a main valve control port K2, a working port a, a pilot valve 1, a controller 11, a processor 11a, an M/a analog-to-digital converter 11b, an input/output interface circuit 11c, a display circuit 11d, a power supply 11e, a solenoid valve drive circuit 11f, a pilot valve module 12, an air intake solenoid valve 12a, an exhaust solenoid valve 12b, a pressure sensor 12c, an air passage bottom plate 12d, an outer cover 13, a main valve 2, a pilot valve interface 2a, a right control chamber 2b, a valve body 21, a valve core 22, a groove 22a, a left end cover 23, a right end cover 24, a bump 24a, a spring 25, a seal ring 26, screw 27, a, The movement sensing part 3 b.
As shown in figures 1 to 8 of the drawings,
a pilot type proportional flow valve with a position feedback function comprises a pilot valve 1 and a main valve 2 which are communicated, wherein the pilot valve 1 is provided with a pilot valve air inlet P1, a pilot valve pressure relief port R1 and a pilot valve control port K1, and the pilot valve 1 comprises a controller 11 and a pilot valve module 12; the main valve 2 is provided with a main valve air supply port P2, a main valve exhaust port R2, a main valve control port K2, a working port A and a pilot valve interface 2a, the main valve 2 comprises a valve body 21, a valve core 22, a left end cover 23, a right end cover 24 and a spring 25, and the spring 25 is arranged between the valve core 22 and the left end cover 23; a pilot valve control port K1 of the pilot valve 1 is communicated with a main valve control port K2 of a main valve 2, a main valve control port K2 of the main valve 2 is communicated with a right control chamber 2b of the main valve 2, a displacement sensor 3 for measuring the displacement of a valve core 22 is arranged in the main valve 2, and the displacement sensor 3 is connected with a controller 11 in a feedback way;
the pressure of the pilot valve control port K1 of the pilot valve 1 and the input signal are in a first nonlinear characteristic relation L1, the pressure of the main valve control port K2 of the main valve 2 and the valve port opening degree of the main valve 2 are in a linear relation L2, and the valve port opening degree of the main valve 2 and the output gas flow are in a second nonlinear characteristic relation L3; through laboratory testing, the output gas flow and input signal are corrected to a linear relationship and the pressure value of the intermediate variable pilot valve control port K1 is consolidated into the controller 11.
In an embodiment, the pilot valve module 12 includes an air intake solenoid valve 12a, an exhaust solenoid valve 12b, a pressure sensor 12c and an air circuit bottom plate 12d, the controller 11 is connected to the air intake solenoid valve 12a and the exhaust solenoid valve 12b in a control manner, the pressure sensor 12c is connected to the controller 11 in a feedback manner, the air intake solenoid valve 12a is disposed between the pilot valve air inlet P1 and the pilot valve control port K1, and the exhaust solenoid valve 12b is disposed between the pilot valve pressure relief port R1 and the pilot valve control port K1.
In the embodiment, the controller 11 includes a processor 11a, an M/a analog-to-digital converter 11b, an input/output interface circuit 11c, a display circuit 11d, a power supply 11e, and a solenoid valve driving circuit 11 f.
In the embodiment, the left end of the right end cover 24 is provided with a projection 24a, and a right control chamber 2b is formed between the outer periphery of the projection 24a and the inner wall of the valve body 21.
In the embodiment, the center portion of the spool 22 is provided with a groove 22 a. The notch 22a is located at the main valve supply port P2.
In the embodiment, the displacement sensor 3 includes a fixed portion 3a and a movable sensing portion 3b, the fixed portion 3a is mounted on the left end cap 23, and the movable sensing portion 3b is fixed to the left end of the valve core 22.
In the embodiment, a seal ring 26 is provided between the right end cover 24 and the valve body 21.
In the embodiment, the right end cover 24 and the valve body 21 are fixed by screws 27.
In the embodiment, the controller 11 and the pilot valve module 12 are externally provided with an outer casing 13.
The working principle is as follows:
the pilot type proportional flow valve is composed of a pilot valve 1 and a main valve 2 which are communicated, wherein a pilot valve air inlet P1, a pilot valve pressure relief port R1 and a pilot valve control port K1 are arranged on the pilot valve 1, a main valve air supply port P2, a main valve exhaust port R2, a main valve control port K2, a working port A and a pilot valve interface 2a are arranged on the main valve 2, and 3 ports (shown in figure 7) of the pilot valve interface 2a are correspondingly connected with the pilot valve air inlet P1, the pilot valve pressure relief port R1 and the pilot valve control port K1 on the pilot valve 1. The pilot valve control port K1 communicates with the main valve control port K2, that is, the pilot valve control port K1 is at the same pressure as the main valve control port K2.
As shown in fig. 4, the input signal sets the output pressure value of the pilot valve 1, and the pressure sensor 12c detects the real pressure output by the pilot valve and feeds the real pressure back to the controller 11. After logical operation, the controller 11 issues an operation command to the solenoid valves (the intake solenoid valve 12a and the exhaust solenoid valve 12 b): when the feedback pressure is greater than the set pressure, the air inlet electromagnetic valve 12a is closed, the air outlet electromagnetic valve 12b is opened, the air in the pilot valve control port K1 is exhausted outwards from the pilot valve pressure relief port R1 through the air outlet electromagnetic valve 12b, and the pressure of the pilot valve control port K1 is reduced; on the contrary, when the feedback pressure is smaller than the set pressure, the intake solenoid valve 12a is opened, the exhaust solenoid valve 12b is closed, the pilot valve intake port P1 supplies air to the pilot valve control port K1 through the intake solenoid valve 12a, and the pressure of the pilot valve control port K1 rises. When the feedback pressure is equal to the set pressure, the intake solenoid valve 12a and the exhaust solenoid valve 12b are closed, and at this time, the pressure of the pilot valve control port K1 is dynamically stabilized within the accuracy range allowed by the set pressure, so that the correlation between the pressure of the pilot valve control port K1 and the input signal is established. The pressure of the pilot valve control port K1 and the input signal have a first nonlinear characteristic relation L1.
As shown in fig. 6, the pilot valve control port K1 of the pilot valve 1 communicates with the main valve control port K2 of the main valve 2, and the pressures of both are equal, the main valve control port K2 communicates with the right control chamber 2b of the main valve 2, and the pressure of the right control chamber 2b is used to control the movement of the spool 22 of the main valve 2. The force of the pressure of the right control chamber 2b acting on the valve core 22 is balanced with the spring force of the left end of the valve core 22, so that the valve core 22 stays at a certain position, thereby controlling the opening of the valve port and controlling the flow of the gas. For a certain pressure of the main valve control port K2, a stable opening of the valve port is obtained, and a stable gas flow can be obtained. Thus, a correlation is established between the pressure at the main valve control port K2 and the gas flow rate at the main valve. As shown in fig. 8, in the main valve 2, although the elastic force of the spring 25 and the amount of compression of the spring are in a linear relationship L2, the opening degree of the valve port and the gas flow rate are in a nonlinear relationship due to the gas characteristics, that is, the opening degree of the valve port and the gas flow rate are in a second nonlinear characteristic relationship L3. That is, in the main valve 2, the pressure of the main valve control port K2 of the main valve 2 and the flow rate of the main valve 2 have a nonlinear relationship.
By introducing an intermediate variable, the pressure of the control port, a correlation is established between the output gas flow of the main valve 2 and the input signal. Through the test in a laboratory, the relation between the flow of the main valve and the input signal is corrected into a linear relation, and the data of the output control pressure value of the corresponding intermediate variable-pilot valve is solidified into a controller; in this way, proportional control of the gas flow is achieved.
After the data is solidified, a certain position of the valve core 22 corresponds to a specific flow value, that is, a functional relationship exists between the position of the valve core 22 and the output flow value; meanwhile, a displacement sensor 3 for measuring the displacement of the valve core 22 is arranged in the main valve 2, the displacement sensor 3 is connected with the controller 11 in a feedback mode, and the position feedback of the valve core 22 is established by detecting the real-time position of the valve core 22 through the displacement sensor 3. When the displacement value of the valve core 22 detected by the displacement sensor 3 deviates from the corresponding value after the data is solidified, an instruction is sent out to increase or reduce the output pressure of the pilot valve 1 and make the valve core 22 return to the set balance position.
The control principle of the present proportional flow valve is shown in fig. 8:
an input signal I is input to the controller 11 of the pilot valve 1 to set an output pressure value of the pilot valve 1, and in the pilot valve 1, a specific functional relationship (i.e., a first nonlinear characteristic relationship L1) is established between the input signal I and an output variable P (control port pressure). The output variable P of the pilot valve 1 is used as an input variable P ' of the main valve 2, and in the main valve 2, the input variable P ' outputs a variable, that is, a displacement X of the spool 22 by a spring system, and the displacement X of the spool 22 and the input variable P ' have a linear relationship (that is, a linear relationship L2). The displacement X of the valve body 22 corresponds to the opening degree of the valve port, and there is a functional relationship (i.e., a second nonlinear characteristic relationship L3) between the opening degree of the valve port and the output flow Q. The functional relation between the opening degree of the valve port and the output flow Q is inherent to the valve structure, the valve structure has a nonlinear relation, and specific values of the functional relation can be obtained through testing in a laboratory.
The relationship from the input signal I to the output flow Q is established in the above way, and the whole relationship chain includes 2 sets of non-linear relationship (the first non-linear characteristic relationship L1 and the second non-linear characteristic relationship L3) and one set of linear relationship (the linear relationship L2), wherein the linear relationship L2 is determined by the spring characteristic, and the second non-linear characteristic relationship L3 can be obtained by testing in the laboratory. By superimposing the first nonlinear characteristic relationship L1, the linear relationship L2, and the second nonlinear characteristic relationship L3, the linear relationship between the input signal I and the output flow Q can be artificially established by laboratory tests. Thereby obtaining a specific function of the first nonlinear characteristic relation L1 and solidifying the function into the embedded software of the pilot valve 1.
The displacement sensor 3 monitors the real-time position of the spool 22 and feeds back the position to the controller 11 of the pilot valve 1, and establishes a closed-loop feedback of the spool 22 position to dynamically maintain the output flow rate of the main valve 2 within a range of variation allowed by a set value.
Therefore, the proportional control of the flow is realized, the proportional valve which is suitable for the gas environment and can accurately control the flow is realized, and the stability of flow output and the sensitivity of reaction are improved.
While the preferred embodiments of the present invention have been illustrated, various changes and modifications may be made by those skilled in the art without departing from the scope of the present invention.
Claims (9)
1. A pilot type proportional flow valve with a position feedback function comprises a pilot valve (1) and a main valve (2) which are communicated, and is characterized in that the pilot valve (1) is provided with a pilot valve air inlet (P1), a pilot valve pressure relief opening (R1) and a pilot valve control opening (K1), and the pilot valve (1) comprises a controller (11) and a pilot valve module (12); the main valve (2) is provided with a main valve air supply port (P2), a main valve exhaust port (R2), a main valve control port (K2), a working port (A) and a pilot valve interface (2a), the main valve (2) comprises a valve body (21), a valve core (22), a left end cover (23), a right end cover (24) and a spring (25), and the spring (25) is arranged between the valve core (22) and the left end cover (23); the pilot valve control port (K1) of the pilot valve (1) is communicated with a main valve control port (K2) of a main valve (2), the main valve control port (K2) of the main valve (2) is communicated with a right control cavity (2b) of the main valve (2), a displacement sensor (3) for measuring the displacement of a valve core (22) is arranged in the main valve (2), and the displacement sensor (3) is in feedback connection with a controller (11);
the pressure of a pilot valve control port (K1) of the pilot valve (1) is in a first nonlinear characteristic relation (L1) with an input signal, the pressure of a main valve control port (K2) of a main valve (2) is in a linear relation (L2) with the valve port opening degree of the main valve (2), and the valve port opening degree of the main valve (2) is in a second nonlinear characteristic relation (L3) with an output gas flow; through laboratory tests, the output gas flow and input signal are corrected to form a linear relationship, and the pressure value of the intermediate variable pilot valve control port (K1) is solidified into the controller (11).
2. The pilot-operated proportional flow valve with position feedback function according to claim 1, characterized in that: pilot valve module (12) including air inlet solenoid valve (12a), exhaust solenoid valve (12b), pressure sensor (12c) and air circuit bottom plate (12d), controller (11) and air inlet solenoid valve (12a), exhaust solenoid valve (12b) control connection, pressure sensor (12c) feedback connection in controller (11), air inlet solenoid valve (12a) set up between pilot valve air inlet (P1) and pilot valve control mouth (K1), exhaust solenoid valve (12b) set up between pilot valve pressure relief mouth (R1) and pilot valve control mouth (K1).
3. The pilot-operated proportional flow valve with position feedback function according to claim 2, characterized in that: the controller (11) comprises a processor (11a), an M/A analog-to-digital converter (11b), an input/output interface circuit (11c), a display circuit (11d), a power supply (11e) and an electromagnetic valve driving circuit (11 f).
4. The pilot-operated proportional flow valve with position feedback function according to claim 3, characterized in that: the left end of the right end cover (24) is provided with a convex block (24a), and a right control cavity (2b) is formed between the periphery of the convex block (24a) and the inner wall of the valve body (21).
5. The pilot-operated proportional flow valve with position feedback function according to claim 4, characterized in that: a groove (22a) is formed in the middle of the valve core (22).
6. The pilot-operated proportional flow valve with position feedback function according to claim 5, characterized in that: the displacement sensor (3) comprises a fixed part (3a) and a movable sensing part (3b), the fixed part (3a) is installed on the left end cover (23), and the movable sensing part (3b) is fixed at the left end of the valve core (22).
7. The pilot-operated proportional flow valve with position feedback function according to claim 6, wherein: and a sealing ring (26) is arranged between the right end cover (24) and the valve body (21).
8. The pilot-operated proportional flow valve with position feedback function according to claim 7, wherein: the right end cover (24) and the valve body (21) are fixed through a screw (27).
9. The pilot-operated proportional flow valve with position feedback function according to claim 8, wherein: and an outer housing (13) is arranged outside the controller (11) and the pilot valve module (12).
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| Application Number | Priority Date | Filing Date | Title |
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| CN202020701576.1U CN212028721U (en) | 2020-04-30 | 2020-04-30 | Pilot-operated proportional flow valve with position feedback function |
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| CN202020701576.1U CN212028721U (en) | 2020-04-30 | 2020-04-30 | Pilot-operated proportional flow valve with position feedback function |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113202840A (en) * | 2021-04-30 | 2021-08-03 | 江苏科迈液压控制系统有限公司 | Judgment method and compensation method for high-frequency-response large-flow hydraulic valve main valve core cavity backlash oscillation |
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2020
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113202840A (en) * | 2021-04-30 | 2021-08-03 | 江苏科迈液压控制系统有限公司 | Judgment method and compensation method for high-frequency-response large-flow hydraulic valve main valve core cavity backlash oscillation |
| CN113202840B (en) * | 2021-04-30 | 2022-06-10 | 江苏科迈液压控制系统有限公司 | High-frequency-response large-flow hydraulic valve main valve core cavity clearance oscillation compensation method |
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