阅读说明：本技术 一种基于人工智能的多功能阀门 (Multifunctional valve based on artificial intelligence ) 是由 王福杰 秦毅 胡耀华 任斌 姜鸣 郭芳 姚智伟 于 2021-01-12 设计创作，主要内容包括：本发明公开了一种基于人工智能的多功能阀门,基于人工智能的多功能阀门,包括：用于与气源连接的气源净化单元；与所述气源净化单元连接用于控制阀门执行器的防堵塞电气转换单元；与所述防堵塞电气转换单元连接,用于向所述防堵塞电气转换单元发出控制信号的电路控制单元；与所述电路控制单元连接,用于检测阀门执行器的执行位置的位置反馈单元。智能阀门,包括基于人工智能的多功能阀门以及与所述基于人工智能的多功能阀门配合的阀门执行器。本发明实现智能化阀门定位,并能够有效避免因为气源污染而造成内部堵塞,特别适用于工业现场环境的过程控制。(The invention discloses a multifunctional valve based on artificial intelligence, which comprises: the air source purifying unit is used for being connected with an air source; the anti-blocking electric conversion unit is connected with the air source purification unit and is used for controlling a valve actuator; the circuit control unit is connected with the anti-blocking electric conversion unit and used for sending a control signal to the anti-blocking electric conversion unit; and the position feedback unit is connected with the circuit control unit and is used for detecting the execution position of the valve actuator. The intelligent valve comprises a multifunctional valve based on artificial intelligence and a valve actuator matched with the multifunctional valve based on artificial intelligence. The intelligent valve positioning device realizes intelligent valve positioning, can effectively avoid internal blockage caused by air source pollution, and is particularly suitable for process control of industrial field environment.)

1. A multifunctional valve based on artificial intelligence, comprising:

the air source purifying unit is used for being connected with an air source;

the anti-blocking electric conversion unit is connected with the air source purification unit and is used for controlling the valve actuator;

the circuit control unit is connected with the anti-blocking electric conversion unit and used for sending a control signal to the anti-blocking electric conversion unit;

and the position feedback unit is connected with the circuit control unit and is used for detecting the execution position of the valve actuator.

2. The artificial intelligence based multi-functional valve of claim 1, wherein the gas source purification unit comprises: the filter screen comprises a fiber filter screen, a negatively charged electric grid, a positively charged filter screen and a carbonaceous filter screen which are sequentially arranged along the inlet direction of an air source.

3. The artificial intelligence based multi-functional valve of claim 1, further comprising: and the impurity cleaning unit is connected with the air source purification unit and is used for cleaning impurities in the air source purification unit.

4. The artificial intelligence based multifunctional valve according to claim 3, wherein the impurity cleaning unit comprises: the first check valve, airtight gas circuit and the second check valve that connect gradually, first check valve with the air supply purification unit is connected, the second check valve be connected with the impurity removal air supply.

5. The artificial intelligence based multi-functional valve of claim 1, wherein the anti-jam electrical switching unit comprises: the pneumatic control valve comprises a pneumatic input passage, a pneumatic output passage and an exhaust passage which are mutually communicated through a working passage, wherein the working passage is provided with a connecting rod, one end of the connecting rod is fixedly provided with a first baffle plate for closing the working passage between the pneumatic input passage and the pneumatic output passage, the other end of the connecting rod is fixedly provided with a second baffle plate for closing the working passage between the pneumatic output passage and the exhaust passage, and the connecting rod and the first baffle plate and the second baffle plate on the connecting rod are driven by a piezoelectric actuator;

the pneumatic input passage is connected with the air source purification unit, the pneumatic output passage is connected with the valve positioner, and the piezoelectric actuator is connected with the circuit control unit.

6. The artificial intelligence based multifunctional valve according to claim 5, wherein the joints of the air pressure input passage, the air pressure output passage and the exhaust passage with the working channel are connected by arc-shaped surfaces.

7. The multifunctional artificial intelligence based valve according to claim 1, wherein the circuit control unit comprises:

a signal acquisition circuit;

the microprocessor is connected with the signal acquisition circuit;

the pulse width modulation control circuit is connected with the microprocessor;

the pulse width modulation control circuit is connected with the anti-blocking electric conversion unit.

8. The multi-functional valve based on artificial intelligence of claim 7, wherein the circuit control unit further comprises: and the keyboard input circuit is connected with the microprocessor.

9. The multi-functional valve based on artificial intelligence of claim 7, wherein the circuit control unit further comprises: and the liquid crystal display circuit is connected with the microprocessor.

Technical Field

The invention relates to the field of valve positioners, in particular to a multifunctional valve based on artificial intelligence.

Background

The valve positioner is a main accessory of a control valve, and takes a valve rod displacement signal as an input feedback measurement signal, takes a controller output signal as a setting signal, compares the two signals, and changes the output signal of the actuator to enable the actuator to act when the two signals have deviation, so that the one-to-one correspondence relationship between the valve rod displacement and the controller output signal is established. Therefore, the valve positioner forms a feedback control system which takes the displacement of the valve rod as a measuring signal and takes the output of the controller as a setting signal. The manipulated variable of the control system is the output signal of the valve positioner to the actuator.

Valve positioners matched with pneumatic actuators have universal intelligent valve positioner products at home and abroad at present, wherein the intelligent valve positioner products of siemens, ABB and other companies are taken as representatives, and in order to realize the universality of the intelligent valve positioners, the intelligent valve positioners mostly adopt an electric conversion mechanism such as a nozzle baffle or a piezoelectric valve to realize the control of the pressure or the ventilation flow of the actuators so as to ensure the opening and closing speed of the valves and the response capability in the adjusting process.

However, because the positioner adopts the electric conversion element with high precision, the internal gas path is long and the aperture is small, and the positioner has high requirements on the quality of a gas source. Along with the increase of smoke dust generated by heat supply and combustion in the industrial process, the increase of automobile exhaust emission and other reasons, the content of particulate matters in the air continuously rises, so that the phenomenon of abnormal work caused by the blockage of an air inlet or an exhaust port of a piezoelectric valve can occur after the conventional pneumatic intelligent valve positioner is used for a period of time.

The chinese patent application publication No. CN101650555A (application No. 200910101852.9) discloses an intelligent electric valve positioner, which comprises a control unit, an I/P conversion unit, a valve position detection feedback unit, and a power supply unit, wherein the power supply unit comprises a current sampling circuit and a voltage stabilizing circuit for receiving a valve control signal, and an output end of the voltage stabilizing circuit is connected to a low dropout linear regulator for driving the control unit, the I/P conversion unit, and the valve position detection feedback unit to work; the current sampling circuit is composed of a resistor and an amplifier, wherein the two ends of the resistor are respectively connected with the negative end of the valve control signal and the grounding end of the voltage stabilizing circuit, and the amplifier is in resistor connection, the output end of the amplifier is connected with the control unit, so that the intelligent electric valve positioner is smaller in power consumption and higher in precision, but the intelligent positioner uses the I/P conversion unit, and adverse effects caused by air source pollution are not considered.

The chinese patent application of the grant publication No. CN103216664A (application No. 201310143943.5) discloses an intelligent valve positioner, which comprises a piezoelectric module, wherein the piezoelectric module comprises an air inlet chamber having an air inlet and an air outlet, and a sealing ball for sealing or opening the air inlet of the air inlet chamber, the air inlet is a tapered hole with a gradually enlarged cross-sectional diameter along the air inlet direction, the sealing ball is supported by a return spring and movably disposed in the air inlet along the axial line direction of the air inlet, the diameter of the sealing ball is greater than or equal to the minimum cross-sectional diameter of the air inlet and smaller than the maximum cross-sectional diameter of the air inlet, the sealing ball is made of an aluminum alloy material, and the intelligent valve positioner has better oil resistance, water resistance and expansion resistance, so that the service life is longer, the piezoelectric module cannot be damaged due to water inlet, but no good solution is mentioned for air source pollution.

Disclosure of Invention

The invention provides a multifunctional valve based on artificial intelligence, which can effectively avoid internal blockage caused by air source pollution on the premise of having the general application function of the current positioner, and is particularly suitable for process control of industrial field environment.

A multi-functional valve based on artificial intelligence, comprising:

the air source purifying unit is used for being connected with an air source;

the anti-blocking electric conversion unit is connected with the air source purification unit and is used for controlling a valve actuator;

the circuit control unit is connected with the anti-blocking electric conversion unit and used for sending a control signal to the anti-blocking electric conversion unit;

and the position feedback unit is connected with the circuit control unit and is used for detecting the execution position of the valve actuator.

According to the invention, the multifunctional valve based on artificial intelligence is connected with an external gas source, the gas source firstly inputs the gas source into the gas source purification unit for purification, the purified gas is transmitted to the anti-blocking electrical conversion unit to drive the anti-blocking electrical conversion unit, the anti-blocking electrical conversion unit executes operation according to a control signal sent by the circuit control unit, so that the valve actuator is controlled, the position feedback unit feeds the execution position of the valve actuator back to the circuit control unit, the intelligent valve positioning is realized, and the internal blockage caused by gas source pollution can be effectively avoided.

The following are preferred structures of the present invention:

the multifunctional valve based on artificial intelligence still includes: with the impurity cleaning unit that is used for cleaing away impurity in the air supply purification unit is connected to the air supply purification unit, can be after the outage with the particulate matter of filter screen interception inhale and remain including, can manually open the clearance.

The gas source purification unit comprises: the filter screen comprises a fiber filter screen, a negatively charged electric grid, a positively charged filter screen and a carbonaceous filter screen which are sequentially arranged along the inlet direction of an air source. The fiber filter screen can filter particles with larger volume, such as suspended dust, microorganisms and the like. The negatively charged grid and the positively charged screen can adsorb the particles with the opposite electric polarity under the action of the electrodes respectively. The carbonaceous filter screen can absorb chemical gas, and when the gas contains chemical components, the carbonaceous filter screen can effectively absorb the chemical gas so as to protect rear-end electrical equipment.

The impurity cleaning unit comprises: the air purification device comprises a first one-way valve, a closed air circuit and a second one-way valve which are sequentially connected, wherein the first one-way valve is connected with an air source purification unit (specifically a fiber filter screen, a negatively charged electric grid or a positively charged filter screen, preferably a positively charged filter screen), and the second one-way valve is connected with an impurity removal air source. The impurity removing gas source adopts high-pressure gas, and specifically can adopt high-pressure air. And a second one-way valve is used for isolating the impurity removal air source for secondary protection. When the power is off, the positively charged filter screen and the negatively charged grid are not charged and do not have adsorption capacity, so that the particles adsorbed when the positively charged filter screen and the negatively charged grid are charged, the large-size particles filtered by the fiber filter screen and the like can be blown out from the air inlet in the opposite direction, and the particles, the dust and the like adsorbed by the air source purifying unit are blown out from the air inlet in the opposite direction by adopting high-pressure gas through the impurity removing air source, so that the simple cleaning effect is achieved.

The anti-blocking electrical conversion unit can adopt a pilot three-way valve, and comprises: the pneumatic control valve comprises a pneumatic input passage, a pneumatic output passage and an exhaust passage which are mutually communicated through working passages, wherein the working passages are provided with connecting rods, one ends of the connecting rods are fixedly provided with first baffle plates for sealing the working passages between the pneumatic input passage and the pneumatic output passage, the other ends of the connecting rods are fixedly provided with second baffle plates for sealing the working passages between the pneumatic output passage and the exhaust passage, and the first baffle plates and the second baffle plates on the connecting rods are driven by a piezoelectric actuator.

The piezoelectric actuator drives the connecting rod and the first baffle and the second baffle on the connecting rod, in a first working state, the first baffle seals a working channel between the air pressure input passage and the air pressure output passage, the second baffle does not seal the working channel between the air pressure output passage and the exhaust passage, and then the air pressure output passage is communicated with the exhaust passage and can exhaust air through the exhaust passage. In the second working state, the first baffle plate does not seal the working channel between the air pressure input passage and the air pressure output passage, the second baffle plate seals the working channel between the air pressure output passage and the exhaust passage, the air pressure input passage is communicated with the air pressure output passage, and the air pressure input passage is connected with the valve positioner to drive the valve positioner. Between the first working state and the second working state, the air output of the air pressure output passage can be controlled by the piezoelectric actuator, so that the precision control of the valve opening degree in the valve positioner is achieved.

The joints of the air pressure input passage, the air pressure output passage and the exhaust passage and the working channel are connected by arc-shaped surfaces, so that impurities are prevented from being deposited at the corners inside the air passage.

The pneumatic input passage is connected with the air source purification unit, the pneumatic output passage is connected with the valve positioner, and the piezoelectric actuator is connected with the circuit control unit and controlled by the circuit control unit.

The circuit control unit comprises:

a signal acquisition circuit;

a microprocessor (singlechip) connected with the signal acquisition circuit;

a Pulse Width Modulation (PWM) control circuit connected to the microprocessor;

the pulse width modulation control circuit is connected with the anti-blocking electric conversion unit.

The PWM control circuit functions as an electrical conversion control circuit.

The circuit control unit further comprises: and the keyboard input circuit is connected with the microprocessor. The control signal can be input into the microprocessor (single chip microcomputer) through the keyboard input circuit.

The circuit control unit further comprises: and the liquid crystal display circuit is connected with the microprocessor. The parameters in the microprocessor (single chip microcomputer) can be displayed through the liquid crystal display circuit.

The circuit control unit further comprises: and the power supply circuit is connected with the microprocessor (singlechip). The circuit control unit further comprises: and the feedback output circuit is connected with the microprocessor and is used for being connected with other control terminals.

The position feedback unit comprises an angular displacement sensor, detects the current position of a valve rod in the valve actuator and transmits the current position to the circuit control unit.

Compared with the prior art, the invention has the following advantages:

in the invention, the gas source purification unit is used for filtering and purifying the passing gas and discharging the impurity part to the detachable impurity cleaning unit; the anti-blocking electric conversion unit has higher gas permeability than a common piezoelectric module or a common nozzle baffle plate; and the circuit control unit adjusts the air output of the anti-blocking electric conversion unit according to the information of the acquisition setting signal and the position feedback unit, so as to achieve the precise control of the valve opening degree in the valve positioner.

According to the invention, the air source purification unit is added, the anti-blocking electric conversion unit is improved, and the purpose of long-time stable use can be achieved by effectively preventing particulate matters in air from remaining in the positioner.

Drawings

FIG. 1 is a schematic diagram of the basic structure of the intelligent valve of the present invention;

FIG. 2 is a schematic diagram of the basic structure of the air supply purification unit of the present invention;

FIG. 3 is a schematic diagram of the basic structure of the anti-jam electrical converter unit of the present invention;

FIG. 4 is a schematic diagram of a basic structure of a circuit control unit according to the present invention;

fig. 5 is a schematic diagram of a basic structure of the impurity cleaning unit according to the present invention.

Detailed Description

In order that the objects and advantages of the invention will be more clearly understood, the invention is further described below with reference to examples; it should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and do not limit the scope of the present invention.

It should be noted that in the description of the present invention, the terms of direction or positional relationship indicated by the terms "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, which are only for convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

Furthermore, it should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

As shown in fig. 1, the intelligent valve of the present invention includes a multifunctional valve based on artificial intelligence (abbreviated as positioner, i.e., part inside the frame of fig. 1) and a valve actuator cooperating with the multifunctional valve based on artificial intelligence. Multifunctional valve based on artificial intelligence includes: the air source purification unit 1 is used for being connected with an air source, and the air source is firstly input into the air source purification unit 1; the anti-blocking electric conversion unit 2 is connected with the air source purification unit 1 and is used for controlling a valve actuator; the circuit control unit 4 is connected with the anti-blocking electric conversion unit 2 and used for sending a control signal to the anti-blocking electric conversion unit 2; a position feedback unit 5 connected to the circuit control unit 4 for detecting an execution position of the valve actuator; and the impurity cleaning unit 3 is connected with the gas source purification unit 1 and is used for cleaning impurities in the gas source purification unit 1.

After receiving the external setting signal, the circuit control unit 4 adjusts the ventilation volume of the anti-clogging electrical conversion unit 2, so as to achieve the purpose of controlling the opening of the valve. Before the gas enters the anti-blocking electric conversion unit 2, the gas is filtered and purified by the gas source purification unit 1, so that the contaminated gas containing particles can be effectively prevented from entering the gas path of the multifunctional valve based on artificial intelligence, and the gas path is prevented from being blocked or reduced; the position feedback unit 5 collects signals of the current position of the valve to inform the circuit control unit 4 whether to continue to control the electrical regulation. The impurity cleaning unit 3 can be opened under the condition of power failure to treat the particles intercepted by the air source purifying unit 1.

As shown in fig. 2, the gas source purifying unit 1 includes: and the fiber filter screen 11, the negatively charged electric grid 12, the positively charged filter screen 13 and the carbonaceous filter screen 14 are sequentially arranged along the air source inlet direction. The fiber screen 11 can filter large particles such as suspended dust, microorganisms, etc. The fiber filter screen 11 can intercept particulate matter and guide into the impurity cleaning unit 3 after gathering for convenient removal. The negatively charged grid 12 and the positively charged screen 13 are capable of adsorbing particles of opposite electrical polarity respectively under the influence of the electrodes. The carbonaceous filter 14 can absorb chemical gas, and when the gas contains chemical components, the carbonaceous filter 14 can effectively absorb the chemical gas so as to protect rear-end electrical equipment.

As shown in fig. 3, for the anti-blocking electrical converter unit 2, a pilot three-way valve may be used, and the anti-blocking electrical converter unit includes: the pneumatic control device comprises a pneumatic input passage 21, a pneumatic output passage 22 and an exhaust passage 23 which are communicated with each other through a working passage 24, the working passage 24 is provided with a connecting rod 25, one end of the connecting rod 25 is fixed with a first baffle 26 for closing the working passage 24 between the pneumatic input passage 21 and the pneumatic output passage 22, the other end of the connecting rod 25 is fixed with a second baffle 27 for closing the working passage 24 between the pneumatic output passage 22 and the exhaust passage 23, and the connecting rod 25 and the first baffle 26 and the second baffle 27 on the connecting rod 25 are driven by a piezoelectric actuator 28. The joints of the air pressure input passage 21, the air pressure output passage 22 and the exhaust passage 23 with the working channel 24 are all connected by arc surfaces, so that impurities are prevented from being deposited at the corners inside the air passage. The air pressure input passage 21 is connected with the air source purifying unit 1, the air pressure output passage 22 is connected with the valve positioner, the piezoelectric actuator 28 is connected with the circuit control unit 4, the piezoelectric actuator 28 is controlled by the circuit control unit 4, and the piezoelectric actuator 28 can adopt piezoelectric ceramics.

The inner wall structures of the anti-blocking electric conversion unit 2 are all connected in an arc shape, so that the particle residues can be effectively prevented even under the condition that the air source is not completely purified. And traditional electrical conversion unit is especially easy at the right angle turn accumulated particulate matter, when accumulating to a certain degree, just can influence the normal through of air current, produces the influence or directly leads to the locator to damage to locator location effect.

As shown in fig. 4, the circuit control unit 4 includes: a signal acquisition circuit 42; the microprocessor 45 is connected with the signal acquisition circuit 42, and the microprocessor 45 can adopt a single chip microcomputer; a Pulse Width Modulation (PWM) control circuit 46 connected to the microprocessor 45; a keyboard input circuit 43 connected to the microprocessor 45; a liquid crystal display circuit 44 connected to the microprocessor 45; a feedback output circuit 47 is connected to the microprocessor 45 for connection to other control terminals. The pwm control circuit 46 is connected to the anti-jam electrical conversion unit 2. Control signals may be input to the microprocessor 45 via the keypad input circuit 43. Various parameters within the microprocessor 45 may be displayed by the liquid crystal display circuit 44. A

The circuit control unit 4 receives an external 4-20 mA current setting signal, and the current signal is converted into a voltage signal of 3.3V through the power circuit 41 and supplied to the single chip microcomputer system and a voltage signal of 24V through the power circuit and supplied to the anti-blocking electric conversion unit 2; on the other hand, the current signal is read as a valve position set value inside the single chip microcomputer through the signal acquisition circuit 42. After reading the set position value, the microprocessor 45 controls the PWM control circuit 46 to perform on-off adjustment of the anti-clogging electric conversion unit 2, and outputs gas to operate the valve actuator. When the valve actuator acts, the position feedback unit 5 can acquire the position of the valve rod and input the acquired position to the signal acquisition circuit 42, and when the position feedback signal value is consistent with the set signal, the single chip microcomputer stops PWM adjustment, so that the valve reaches the preset position. After the microprocessor (i.e., the single chip microcomputer) 45 stops operating, a current position signal is sent to the feedback output circuit 47, and the feedback output circuit 47 transmits the current position signal to an upper computer such as a remote control station and the like to inform the current valve regulation execution effect. The keypad input circuit 43 and the lcd circuit 44 enable manual operation of the positioner for situations requiring manual intervention.

As shown in fig. 5, the impurity cleaning unit 3 includes: the first check valve 31, the closed air path 33 and the second check valve 32 are connected in sequence, and with reference to fig. 2, the first check valve 31 is connected with the filter screen 13 with positive electricity in the air source purification unit 1, and the second check valve 32 is connected with the impurity-removing air source. The impurity removing gas source adopts high-pressure gas, and specifically can adopt high-pressure air. A second one-way valve 32 is used to isolate the secondary protection from the contaminant removal source. When the power is off, the positively charged filter screen 13 and the negatively charged grid 12 are both uncharged and have no adsorption capacity, so that the particles adsorbed when the positively charged filter screen 13 and the negatively charged grid 12 are charged and the particles with larger volume filtered by the fiber filter screen 11 can be blown out from the air inlet in the opposite direction, and therefore, the particles, the dust particles and the like adsorbed by the air source purification unit are blown out from the air inlet in the opposite direction by adopting high-pressure gas through the impurity removing air source, and the effect of simple cleaning is achieved.

Because the air source purifying unit 1 is arranged in the equipment, the integrity and the tightness of the air path are required to be kept, and after the air source purifying unit adsorbs particles, frequent disassembly and cleaning are not recommended, the impurity cleaning unit 3 is particularly arranged in the equipment. The impurity cleaning unit 3 is provided with an independent control shifting sheet, and when the positioner works in a valve switch control state (the air source purification unit 1 and the anti-blocking electric conversion unit 2 are in a working state), the impurity cleaning unit 3 is prohibited to be opened; and when the positioner is not in a valve control state (the air source purification unit 1 and the anti-blocking electric conversion unit 2 are closed), the impurity cleaning unit 3 can be opened. The impurity cleaning unit 3 comprises two one-way valves (namely a first one-way valve 31 and a second one-way valve 32), wherein the first one-way valve 31 is connected beside the positively charged filter screen 13, and after passing through high-pressure air, particles, micro-dust and the like adsorbed on the first one-way valve 31 can be blown out reversely from an air inlet; the second check valve 32 is used for secondary protection by isolating external air, and is connected with the middle by a closed air path 33. The impurity cleaning unit 3 can play a simple cleaning role in daily application of the positioner.

The position feedback unit 5 includes an angular displacement sensor, detects the current position of the valve stem in the valve actuator, and transmits the current position to the circuit control unit 4.

In the invention, the multifunctional valve based on artificial intelligence is connected with an external gas source, the gas source firstly inputs the gas source into the gas source purification unit 1 for purification, the purified gas is transmitted to the anti-blocking electric conversion unit 2 to drive the anti-blocking electric conversion unit 3, the anti-blocking electric conversion unit 3 executes operation according to a control signal sent by the circuit control unit 4, so as to control the valve actuator, the position feedback unit 5 feeds back the execution position of the valve actuator to the circuit control unit 4, thereby realizing intelligent valve positioning and effectively avoiding internal blockage caused by gas source pollution.

So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention; various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.