CN113137519B

CN113137519B - Bistable micro electromagnetic valve and micro pneumatic system

Info

Publication number: CN113137519B
Application number: CN202110541955.8A
Authority: CN
Inventors: 王鹏飞; 程祥; 王皓宇; 于猛; 曹莹泽; 李秉洋; 李振
Original assignee: China Academy of Space Technology CAST
Current assignee: China Academy of Space Technology CAST
Priority date: 2021-05-18
Filing date: 2021-05-18
Publication date: 2021-10-08
Anticipated expiration: 2041-05-18
Also published as: CN113137519A

Abstract

The invention discloses a bistable miniature electromagnetic valve, which comprises a valve body, a valve core and a coil, wherein the valve core is arranged on the valve body; the valve body comprises a cylindrical cavity, and an air inlet and an air outlet are formed in the wall of the cylindrical cavity; the valve core comprises core heads arranged at two ends and a connecting piece for connecting the two core heads, and the core heads are made of permanent magnet materials; the valve core is arranged in the cylindrical cavity of the valve body. The bistable structure of the bistable micro electromagnetic valve ensures that the valve core only consumes energy when switching positions, reduces energy consumption, avoids the heating phenomenon of a coil, and has small volume, safety, reliability and convenient integration and control. The invention also discloses a micro pneumatic system, which integrates a plurality of bistable micro electromagnetic valves, so that the whole structure is compact and multi-path control is convenient.

Description

Bistable micro electromagnetic valve and micro pneumatic system

Technical Field

The invention relates to the technical field of artificial intelligence or tactile feedback, in particular to a bistable micro electromagnetic valve and a micro pneumatic system.

Background

Space on-orbit service and maintenance and deep space exploration of extraterrestrial celestial bodies (such as ' Chang ' e ' moon exploration plan and the like) are considered to be the leading-edge fields of space technological development, have strong outlook, creation subversion and promotion, and have very important roles in exploring life origin and identifying new substance characteristic information of human beings to lead modern technological development. As is well known, in-orbit service and maintenance and detection of unknown stars have a great deal of unpredictable risks, and therefore, in severe, dangerous and harmful environments where humans are difficult to involve or cannot reach, remote controllers such as mobile robots/manipulators, detection vehicles and the like are required to replace humans to complete complex space operation tasks. This means that the space moving technology required by the remote-controlled robot has been developed from a simple structured environment to a complex unstructured environment, and it is necessary to have the touch/force sense and other bionic sensing functions, so as to further promote the human exploration process for unknown terrain, unknown objects, unknown fields and the like on extraterrestrial celestial bodies, and it has very important research significance and application value.

A remote-controlled robot is a machine which can make human sense and mechanically operate distant objects, and mainly operates the robot at a certain place which is not the real position of the robot. The remote control robot comprises: an artificial sensor for sensing an external environment; an actuator movable into a specified environment; and the network channel is communicated with the human. To perform complex spatial tasks, teleoperated robots may also contain artificial devices (such as arms, hands, etc.) for generating forces to perform mechanical work in the environment.

If the user receives sufficient information about the teleoperated robot and its remote environment, he feels as if he is, which is called "telepresence". The illusion of "telepresence" is noticeable when the telerobot passes a large amount of information to the user in a very realistic manner. The main way to achieve this is to achieve transparency of the teleoperation system (which may be defined as correlation of the master and manipulated positions/forces, or matching of the environmental impedance and the operator impedance), in particular by means of a long-to-short information flow in different ways.

Haptic feedback is one of such information flows, playing an important role in enhancing the teleoperational immersive experience. Since the 50 s of the 20 th century, the term "tactile" originated in greek has been used in psychology. This can be an important communication medium following both audio and visual. In order to successfully manipulate objects in a remote environment or virtual/augmented reality, it is required that the user be able to immerse in the environment of the object being manipulated. For this reason, in the past two decades, haptic devices that enable users to feel objects through physical interaction by means of haptic sensation have been developed, i.e., users are allowed to obtain haptic information of sensed objects by sensing feedback force generated by haptic feedback means.

In the teleoperation field, an operator at a near end can remotely control a remote-end telerobot through an interactive flexible tactile feedback glove to realize various operations of grabbing, moving, pinching, fixing objects and the like, meanwhile, the telerobot can identify tactile information of an operated target object, such as motion state, contour, surface roughness, hardness, temperature and the like, and convert the tactile information into an electric signal to be transmitted to the interactive flexible tactile feedback glove in real time, and a tactile feedback structure in the glove can feed back real-time tactile information of a sensed object at the far end so as to simulate real information of a world at the far end. If the operator receives sufficient information about the teleoperated robot and its remote environment and can accurately feed back the remote tactile information in real time through the interactive tactile feedback glove, he feels as if he is, which is called "telepresence". The immersion experience makes up the defect that the space teleoperation field only adopts a visual and auditory interaction mode at the present stage, and opens up a new place in the space teleoperation or Augmented Reality (AR) field. For example, in the process of sampling a target planet, the detection robot firstly identifies the position and other visual information of a substance to be grabbed preliminarily through a remotely shot image, and can grasp the touch information such as the appearance, weight and the like of the substance to be grabbed in real time by utilizing the interactive flexible touch feedback glove, so that an operator can judge whether the substance to be grabbed is a required substance accurately and intuitively, and thus, the detection robot provides the most valuable sample for a detection vehicle with limited sampling space or sampling weight.

The device or the mode for realizing the tactile feedback can be realized by rigid mechanical devices such as a motor, an electromagnet, a hydraulic mechanism and the like generally, but the device or the mode has the problems of complex structure, large volume and the like, so that the applicability of the device or the mode is restricted, and the device or the mode for realizing the tactile feedback has more and more attracted attention from people when the pneumatic technology is applied to the technical field of the tactile feedback along with the development of a flexible pneumatic driver.

In particular, since the haptic feedback system is a small or micro system, elements in general pneumatic technology, etc. are not suitable. In a haptic feedback system, to ensure that the pneumatic actuator operates at a particular pressure, the pneumatic circuit system generally requires a plurality of flow valves to regulate the pneumatic pressure of each pneumatic circuit. For small and micro air channel systems (the size of the solenoid valve is centimeter level), such as a flexible pneumatic soft gripper, a flexible touch feedback driver and the like, the existing commercial pneumatic valve has the disadvantages of large size, larger occupied space, heavier weight and high energy consumption, and the existing micro solenoid valve is often accompanied by serious heating phenomenon, thus being not beneficial to the control and integration of a driving system and hindering the microminiaturization development of the flexible pneumatic driver.

Therefore, how to better utilize the pneumatic technology and solve the control problem of a small or micro air channel system at the same time, and provide a control valve with better applicability is a technical problem that needs to be solved urgently by those skilled in the art.

Disclosure of Invention

Aiming at the technical problems, the invention discloses a bistable micro electromagnetic valve and a micro pneumatic system, wherein the bistable structure ensures that a valve core consumes energy only when in a switching position, reduces energy consumption, avoids the heating phenomenon of a coil, and has the advantages of small volume, safety, reliability and convenience for integration and control. The micro pneumatic system integrates a plurality of bistable micro electromagnetic valves, so that the whole structure is compact, multi-path control is convenient, and the problems in the background technology are solved.

The invention discloses a bistable micro electromagnetic valve which comprises a valve body, a valve core and a coil, wherein the valve core is arranged on the valve body; the valve body comprises a cylindrical cavity, and an air inlet and an air outlet are formed in the wall of the cylindrical cavity; the valve core comprises core heads arranged at two ends and a connecting piece for connecting the two core heads, and the core heads are made of permanent magnet materials; the valve core is arranged in the cylindrical cavity of the valve body, the outer diameter of the core head is matched with the inner diameter of the cylindrical cavity, and the N-S level direction of the core head is parallel to the axial direction of the cylindrical cavity; the valve core can slide in the cylindrical cavity along the axial direction of the cylindrical cavity; the coil is wound outside the valve body and generates a magnetic field parallel to the axial direction of the cylindrical cavity after being electrified; the coil can drive the valve core to move to two ends in the cylindrical cavity of the valve body after being electrified, and when the valve core is positioned at one end in the cylindrical cavity, the air inlet is communicated with the air outlet; when the valve core is positioned at the other end in the cylindrical cavity, one of the core heads seals the air outlet, and the air inlet and the air outlet are cut off and communicated.

On the basis of the technical scheme, the invention can be further improved as follows.

Further, the bistable state miniature electromagnetic valve further comprises adsorption sheets fixed at two ends of the valve body, and the adsorption sheets are made of ferromagnetic materials.

Further, the side wall of the valve body is also provided with an air pressure indicating port communicated with the cylindrical cavity; the inside of the air pressure indicating port is provided with an elastic blocking film, and the outside is provided with scales.

Further, when the valve core is positioned at any end of the valve body, the air inlet is communicated with the air pressure indicating port.

Further, the elastic blocking film falls off when the internal pressure of the valve body is higher than the preset pressure; the air pressure indicating port is of a whistle type structure, and when air flows out, the air pressure indicating port vibrates to produce sound.

Furthermore, the coils are wound at two ends of the valve body and are respectively connected with a power supply for independent control.

Furthermore, an elastic body is arranged on the outer side of the core print.

Further, the axial length of the valve body does not exceed 2 centimeters.

The invention also discloses a miniature pneumatic system, which comprises a gas power source and a plurality of branches connected in parallel; each branch comprises a near-end electromagnetic valve, an air pressure driving unit and a far-end electromagnetic valve; the near-end electromagnetic valve and the far-end electromagnetic valve are any bistable micro electromagnetic valve; the pneumatic driving unit comprises a gas input port and a gas output port; the air inlets of the near-end electromagnetic valves are connected with the gas power source; the gas input port of each pneumatic driving unit is connected with the gas outlet of a near-end electromagnetic valve, and the gas output port of each pneumatic driving unit is connected with the gas inlet of a far-end electromagnetic valve; the control circuit is in circuit connection with the near-end electromagnetic valve and the far-end electromagnetic valve on each branch and is used for controlling the airflow state conversion of each electromagnetic valve.

Further preferably, the pneumatic driving units are arranged according to a preset regular array to form a pneumatic driving array.

The invention has the technical effects and advantages that:

1. the bistable micro electromagnetic valve disclosed by the invention fundamentally solves the heating problem of the coil, so that the power consumption of a single electromagnetic valve is greatly reduced, the reliability is enhanced, and the integration is easy.

2. The bistable miniature electromagnetic valve is provided with an air pressure indicating port to judge the internal air pressure, and the elastic blocking film can play a role in prompting and protecting the valve body and the system from overvoltage.

3. The structure design is reasonable, the whole size can be very small, within 2 cm even 1 cm, and the device is particularly suitable for a miniature pneumatic system.

4. The miniature pneumatic system disclosed by the invention integrates a plurality of bistable miniature electromagnetic valves and an air pressure driving unit, has a compact integral structure, is convenient for multi-path control, can be applied to the artificial intelligence fields of remote pneumatic feedback, tactile feedback and the like, and has corresponding beneficial technical effects due to the beneficial technical effects of the bistable electromagnetic valves.

Drawings

FIG. 1 is a schematic diagram of an external structure of a bistable micro solenoid valve according to an embodiment of the present invention;

FIG. 2 is a schematic structural view of one embodiment of the valve cartridge;

FIG. 3 is an enlarged schematic view of the air pressure indicating port of FIG. 1;

FIG. 4 is a schematic diagram of a gas circuit of a bistable micro solenoid valve provided by the present invention when the valve core sucks up;

FIG. 5 is a schematic view of a gas circuit of the bistable micro solenoid valve provided by the present invention when the valve core is sucking downwards;

FIG. 6 is a schematic structural diagram of an embodiment of a micro pneumatic system provided by the present invention;

fig. 7 is a schematic diagram of an array arrangement of the pneumatic driving units.

Wherein the part numbers in the figures are represented as:

the gas pressure balance valve comprises a valve body 1, a gas inlet 101, a gas outlet 102, a gas pressure indicating port 103, an elastic blocking film 104, a scale 105, a valve core 2, a core print 201, an elastic body 202, a coil 3, an adsorption sheet 4, a gas pressure balance hole 5, a gas power source 6, a micro valve bank 7, a control circuit 8 and a gas pressure driving unit 9.

Detailed Description

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings. The principles and features of the present invention are described below in conjunction with the drawings, it being noted that the embodiments and features of the embodiments in the present application can be combined with each other without conflict. The examples are given solely for the purpose of illustration and are not intended to limit the scope of the invention.

Referring to fig. 1 to 7, fig. 1 is a schematic structural diagram of an embodiment of a bistable micro solenoid valve according to the present invention; FIG. 2 is a schematic structural view of one embodiment of the valve cartridge;

FIG. 3 is an enlarged schematic view of the air pressure indicating port of FIG. 1; FIG. 4 is a schematic diagram of a gas circuit of a bistable micro solenoid valve provided by the present invention when the valve core sucks up; FIG. 5 is a schematic view of a gas circuit of the bistable micro solenoid valve provided by the present invention when the valve core is sucking downwards; FIG. 6 is a schematic structural diagram of an embodiment of a micro pneumatic system provided by the present invention; fig. 7 is a schematic diagram of an array arrangement of the pneumatic driving units.

It should be noted that for clarity of description of the claimed technical solutions, the following description is based on the orientation drawn by the drawings and is not intended to limit the present application.

The invention provides a specific embodiment of a bistable micro electromagnetic valve as shown in fig. 1, which comprises a valve body 1, a valve core 2, a coil 3 and an adsorption sheet 4, wherein the adsorption sheet 4 is made of a ferromagnetic material, and in the embodiment, is an iron flexible sheet. The valve body 1 comprises an air inlet 101, an air outlet 102 and an air pressure indicating port 103, wherein the interiors of the air inlet 101, the air outlet 102 and the air pressure indicating port 103 are communicated with each other; an elastic blocking film 104 is arranged inside the opening of the air pressure indication 103, and scales 105 are arranged outside the opening; the valve core 2 is shown in fig. 2, and comprises core heads 201 arranged at two ends and a connecting piece for connecting the two core heads, the connecting piece is a connecting rod, the core heads 201 are made of permanent magnet materials, and the structure of the valve core 2 is similar to a dumbbell shape. The axial length of the whole valve body 1 does not exceed 2 cm.

In order to reduce impact and avoid noise, the outer side of the core print 201 is coated with an elastic body 202, and the elastic body 202 can be made of silica gel or flexible plastic material; the elastic body 202 is not only used for buffering the impact force generated by the valve body 1 when the valve core 2 moves instantly, but also can be attached to the inner wall of the valve body 1 more closely, so that the air leakage phenomenon is avoided.

The upper part and the lower part of the outer side wall of the valve body 1 are wound with a coil 3, after the coil 3 is electrified, a magnetic field is formed in the valve body 1, and the direction of the magnetic field generated by the coil 3 is parallel to the direction of the magnetic field of the core print 201; the top and the bottom of the valve body 1 are properly provided with the adsorption sheet 4 and fixed; the coil 3 is connected with an external control circuit 8, and the position of the valve core 2 is changed by electrifying, so that the working state of the micro valve is changed.

In order to improve the working flexibility of the miniature electromagnetic valve, the coils 3 are wound at two ends of the valve body and are respectively connected with a power supply for independent control.

In the bistable miniature electromagnetic valve provided by the invention, the valve core 2 is arranged in the cylindrical cavity of the valve body 1, the outer diameter of the core head 201 is matched with the inner diameter of the cylindrical cavity, and the N-S level direction of the core head 201 is parallel to the axial direction of the cylindrical cavity; the valve core 2 can slide along the axial direction of the cylindrical cavity; the coil 3 is wound outside the valve body and generates a magnetic field parallel to the axial direction of the cylindrical cavity after being electrified; after the coil 3 is electrified, the valve core 2 can be driven to move to two ends in the cylindrical cavity of the valve body 1, and when the valve core 2 is positioned at one end in the cylindrical cavity, the air inlet 101 is communicated with the air outlet 102; when the valve core 2 is positioned at the other end in the cylindrical cavity, one of the valve cores seals the air outlet 102, and the air inlet 101 is cut off from the air outlet 102.

Regarding the setting position of the air pressure display port 103, the distance between the two core heads 201 and the moving range of the valve core 2 in the valve body 1 need to be considered, and it is ensured that the air inlet 101 and the air pressure display port 103 are communicated no matter the valve core is in any working position, so as to ensure that the air pressure display port 103 can always detect and feed back the air pressure condition inside the valve body 1.

As shown in fig. 3, when the air pressure display port 103 is ventilated, the elastic blocking film 104 is deformed by the air pressure, the center of the elastic blocking film 104 generates the maximum displacement, and the scale 105 outside the air pressure display port 103 is compared to judge the size of the air pressure inside the valve body 1.

Through setting up elasticity and blocking film 104, not only can be used for judging the inside atmospheric pressure size of valve body 1, can be ejecting when valve body 1 internal pressure is too high moreover, gaseous this moment will show the mouth 103 through atmospheric pressure and spill over, can play the guard action to whole atmospheric pressure system like this, avoid causing the damage because of pressure is too big to whole atmospheric pressure system.

In a further preferred embodiment, the air pressure display port 103 is configured to be a whistle-shaped structure, and during the high-pressure air overflow process, the whistle-shaped structure vibrates to produce sound, so as to give a sound prompt to a technician, thereby facilitating the technician to find a problem and find a corresponding element for replacement.

The upper end and the lower end of the valve body 1 are provided with air pressure balance holes 5 for ensuring the consistency of the upper pressure and the lower pressure of the valve core 2 and being beneficial to the quick movement of the valve core 2.

Specifically, the iron flexible sheet used by the adsorption sheet 4 may be formed by mixing iron powder and PDMS properly and pouring, and cooperates with the core print 201 of the valve element 2, the coil 3 interacts with the core print 201 formed by the corresponding permanent magnet, after the lower coil 3 is energized, the coil 3 generates an acting force to repel the core print 201 below the valve element 2, and overcomes the attraction force between the iron flexible sheet and the core print, the resultant force exerted on the valve element 2 is upward, the core print 201 drives the integral valve element 2 to move upward, and meanwhile, the upper core print 201 and the upper iron flexible sheet generate an attraction force to attract the valve element 2, so that the valve element 2 is stationary, the position of the valve element 2 is an upward-adsorption steady-state position, as shown in fig. 4, in this steady state, the valve element 2 blocks the air outlet 102, and air cannot pass through the valve body. On the contrary, when the upper coil 3 is energized, the coil 3 generates an acting force to repel the core print 201 above the valve core 2, and overcomes the attraction force between the iron flexible sheet and the core print, the resultant force exerted on the valve core 2 is downward, the core print 201 drives the whole valve core 2 to move downward, meanwhile, the core print 201 below and the iron flexible sheet generate an attraction force to attract the valve core 2, so that the valve core 2 is static, the position of the valve core 2 is a downward-suction steady-state position, as shown in fig. 5, in the steady-state, the gas outlet 102 is opened, and the gas can smoothly pass through the valve body 1. Therefore, the micro valve can be switched between the bistable working states all the time, and a bistable structure is formed.

In the specific embodiment of the micro pneumatic system disclosed by the present invention, as shown in fig. 6, the micro pneumatic system comprises a gas power source 6, a micro valve set 7, a control circuit 8 and a pneumatic driving unit 9, wherein the gas power source 6 is connected with a plurality of branches, and each branch is connected with two groups of micro valves and the pneumatic driving unit 9.

Specifically, the micro pneumatic system comprises a gas power source 6 and a plurality of branches connected in parallel; each branch comprises a near-end electromagnetic valve, an air pressure driving unit 9 and a far-end electromagnetic valve; the near-end electromagnetic valve and the far-end electromagnetic valve are both bistable miniature electromagnetic valves as described above; the pneumatic driving unit 9 comprises a gas input port and a gas output port; the air inlets 101 of the near-end electromagnetic valves are all connected with the gas power source 6; a gas input port of each pneumatic driving unit 9 is connected with a gas outlet 102 of a near-end electromagnetic valve, and a gas output port of each pneumatic driving unit 9 is connected with a gas inlet 101 of a far-end electromagnetic valve; the control circuit 8 is electrically connected with the near-end solenoid valve and the far-end solenoid valve on each branch, and is used for controlling the airflow state conversion of each solenoid valve. The pneumatic driving units are arranged according to a preset rule array to form a pneumatic driving array. The pneumatic driving unit 9 is an executing component of pneumatic transmission, and realizes the effect of tactile feedback through the force action fed back by the pneumatic transmission.

The control mode or the working principle of the micro pneumatic system provided by the invention is as follows:

when the valve core 2 of the first group of micro valves (near-end solenoid valve, the same below) sucks up (blocks gas), and simultaneously the valve core 2 of the second group of micro valves (far-end solenoid valve, the same below) sucks up (blocks gas), the gas is sealed in the pneumatic driving unit 9, and the system is in a pressure maintaining state.

When the first set of microvalve spools 2 are sucking down (inputting gas) while the second set of microvalve spools 2 are sucking up (blocking gas), gas is input into the pneumatic drive unit 9 and the system is in a charged state.

When the first group of micro valve spools 2 suck up (block gas) and the second group of micro valve spools 2 suck down (output gas), the gas is exhausted from the pneumatic driving unit 9, and the system is in a gas release state.

Therefore, through the combined operation of the two groups of bistable miniature electromagnetic valves disclosed by the invention, three working states of inflation, pressure maintaining and deflation can be conveniently realized.

By using the micro pneumatic system disclosed by the invention, the air pressure driving units 9 in the branches can be arrayed and arranged in a preset shape in the same plane or arc-shaped curved surface, as shown in fig. 7, an integral driving array is formed, and accurate touch feedback can be realized by controlling the action of each air pressure driving unit 9.

The micro pneumatic system disclosed by the invention can be further applied to the field of virtual/augmented reality. Augmented reality (virtual reality) refers to a technology for calculating the position and angle of a camera image in real time and adding corresponding images, videos and 3D models, and the aim of the technology is to sleeve a virtual world on a screen in the real world and interact with the virtual world. The tactile feedback device manufactured by the miniature electromagnetic valve and the miniature pneumatic system provided by the invention can be used for tactile feedback in virtual/augmented reality, so that a user can feel an object in a virtual environment in an immersive manner.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A bistable miniature electromagnetic valve is characterized by comprising a valve body, a valve core and a coil;

the valve body comprises a cylindrical cavity, and an air inlet and an air outlet are formed in the wall of the cylindrical cavity;

the valve core comprises core heads arranged at two ends and a connecting piece for connecting the two core heads, and the core heads are made of permanent magnet materials;

the valve core is arranged in the cylindrical cavity of the valve body, the outer diameter of the core head is matched with the inner diameter of the cylindrical cavity, and the N-S level direction of the core head is parallel to the axial direction of the cylindrical cavity;

the valve core can slide in the cylindrical cavity along the axial direction of the cylindrical cavity;

the coil is wound outside the valve body and generates a magnetic field parallel to the axial direction of the cylindrical cavity after being electrified;

the coil can drive the valve core to move to two ends in the cylindrical cavity of the valve body after being electrified, and when the valve core is positioned at one end in the cylindrical cavity, the air inlet is communicated with the air outlet; when the valve core is positioned at the other end in the cylindrical cavity, one of the valve core heads seals the air outlet, and the air inlet and the air outlet are cut off and communicated;

the side wall of the valve body is also provided with an air pressure indicating port communicated with the cylindrical cavity; the inside of the air pressure indicating port is provided with an elastic blocking film, and the outside of the air pressure indicating port is provided with scales;

the elastic blocking film falls off when the pressure in the valve body is higher than the preset pressure;

the air pressure indicating port is of a whistle type structure, and when air flows out, the air pressure indicating port vibrates to produce sound.

2. The bistable micro solenoid valve of claim 1, further comprising an absorption piece fixed to two ends of said valve body, wherein said absorption piece is made of ferromagnetic material.

3. The bistable micro solenoid valve of claim 1, wherein said inlet port is in communication with said air pressure port when said spool is at either end of said valve body.

4. The bistable micro solenoid valve of claim 1, wherein said coil is wound around both ends of said valve body and independently controlled by the power supply.

5. The bistable micro solenoid valve of claim 1, wherein said core is provided with an elastomer on the outside.

6. A bistable micro-solenoid valve according to claim 1, wherein said valve body has an axial length not exceeding 2 cm.

7. A micro pneumatic system comprises a gas power source and a plurality of branches connected in parallel; the pneumatic control system is characterized by further comprising control circuits, wherein each branch comprises a near-end electromagnetic valve, a pneumatic driving unit and a far-end electromagnetic valve;

the near-end solenoid valve and the far-end solenoid valve are both bistable solenoid valves as claimed in any one of claims 1 to 6;

the pneumatic driving unit comprises a gas input port and a gas output port;

the air inlets of the near-end electromagnetic valves are connected with the gas power source;

the gas input port of each pneumatic driving unit is connected with the gas outlet of a near-end electromagnetic valve, and the gas output port of each pneumatic driving unit is connected with the gas inlet of a far-end electromagnetic valve;

the control circuit is in circuit connection with the near-end electromagnetic valve and the far-end electromagnetic valve on each branch and is used for controlling the airflow state conversion of each electromagnetic valve.

8. The micro-pneumatic system of claim 7, wherein the pneumatic drive units are arranged in a predetermined regular array to form a pneumatic drive array.