A normally closed sealing structure, a vacuum isolation hatch, and a vacuum pipeline connection method

Abstract

The present invention relates to a normally closed sealing structure, a vacuum isolation hatch, and a vacuum pipeline connection method. The normally closed sealing structure includes a box body and a sealing door. A sealing end face and a first driving mechanism are provided in the box body. The sealing door and the first driving mechanism are arranged on a valve plate. An end face sealing ring and a spring are provided on the sealing door. The two ends of the spring act on the sealing door and the first driving mechanism respectively. The end face sealing ring is pressed against the sealing end face by the spring force of the spring. The first driving mechanism can drive the sealing door to compress the spring and move away from the sealing end face. The present invention does not require the first driving mechanism to work. The end face sealing ring is pressed against the sealing end face only by the spring force provided by the spring, so that the vacuum isolation hatch is normally closed, which can effectively save the use cost. The first driving mechanism pulls the sealing door to compress the spring, so that the end face sealing ring can be moved away from the sealing end face, so that the sealing of the normally closed vacuum isolation hatch is released, and preparations can be made for the subsequent connection of the vacuum pipeline, with good effects.

Description

Technical Field

[0001] The invention relates to the field of vacuum magnetic suspension, in particular to a normally closed sealing structure, a vacuum isolation cabin door, and a vacuum pipeline connecting method. Background Art

[0002] Fluid conveying pipeline systems usually use gate valves, stop valves, butterfly valves, ball valves, plug valves, etc. to realize the opening and closing of fluid conveying pipeline systems. These valves are widely used in pipeline systems for conveying liquid water, liquid oil, gaseous materials, fluidized materials, etc.

[0003] At present, most of these valves are single-position switch valves, which are suitable for pipelines with smaller diameters. The pipeline system is unable to transport magnetic levitation vehicles or solid materials, and cannot perform on-off switching during the transportation process.

[0004] The on-off valve currently used for the passage of tangible objects is a gate cut-off valve. The gate valve is an opening and closing gate whose movement direction is perpendicular to the movement direction of the object. There are two types of gate valves: wedge gate valves and parallel gate valves.

[0005] The two sealing surfaces of the wedge gate form a wedge shape, and the sealing is achieved by the compression pressure between the wedge sealing surface and the valve body sealing surface ensured by the valve stem thrust. The processing requirements for the wedge gate and the wedge sealing surface of the valve body are high and easy to wear. The valve stem thrust needs to be kept constant for a long time. It is only suitable for gate shut-off valves with small and medium diameters and cannot meet the switching and sealing needs of vacuum magnetic levitation vacuum pipelines.

[0006] The sealing surface of the parallel gate valve is parallel to the moving direction of the gate. The parallel gate valve is mainly composed of the gate, sealing device, sealing actuator, gate moving mechanism, valve body, etc. The movement of the gate is achieved by the rotation of the trapezoidal thread screw nut pair. There are two types of drive: manual and electric. For large gate valves, electric drive is used to move the gate to the open position and the closed position. The sealing of the parallel gate valve is achieved by a plurality of parallel four-bar mechanisms composed of the top rod mechanism of the sealing actuator, the inclined rod mechanism and the sealing plate of the sealing device to push the sealing plate outward in parallel. The inclined rod mechanism changes from tilted to vertical until the sealing ring on the sealing plate abuts against the sealing end face of the valve body, meets and maintains the sealing force requirements, and achieves sealing and closing the gate valve; the driving of the sealing actuator is also achieved by the trapezoidal thread screw nut pair.

[0007] In order to ensure the reliable and stable operation of the sealing device, sealing actuator, gate plate and moving mechanism, it is also necessary to set up: (1) multiple sets of panel support wheels and side plate guide wheels to ensure that the valve plate moves smoothly in the valve body with the valve body or guide rail as a guide, (2) multiple sets of rollers are set on the valve plate. When the valve plate moves to the valve port, the valve plate rollers are in place and the valve plate stops moving forward, (3) multiple sets of sealing plate wheels for guiding the sealing plate, and (4) valve plate load-bearing wheels and guide wheel groups for bearing the weight of the entire valve plate and the various mechanisms installed thereon.

[0008] Therefore, the parallel gate valve has many mechanisms and complex structure, is difficult to manufacture, has high cost and high failure rate; its sealing device and sealing actuator are both arranged inside the gate, and after failure, they are inspected, maintained and replaced unchanged; the opening and closing of the sealing device are realized by multiple sets of parallel four-bar mechanisms and multiple sets of panel support wheels. Due to the inevitable errors in manufacturing and installation and the large number of conversion links, the flatness of the sealing surface of the sealing plate is low, the sealing effect is not ideal, and it is difficult to meet the sealing and switching requirements of such large magnetic levitation vacuum pipelines.

[0009] In view of the existing technologies of various switch shut-off valves, for special working conditions such as vacuum working environment, large tangible solid magnetic levitation trains passing through, large diameter of vacuum pipes (generally 3m to 8m), and high sealing requirements, the existing gate valve sealing structure technology has sealing problems and many shortcomings, and the electric actuator drives the sealing device to match the sealing surface. After the sealing device is in place, since the sealing device needs to bear pressure, the electric actuator needs to be in a working load-bearing state to avoid failure of the sealing device. For the use of electric seals in normally closed pipelines, electric energy needs to be consumed daily to make the electric actuator work, resulting in a very high cost of pipeline use, which is difficult to meet the sealing and switching requirements of magnetic levitation vacuum pipelines. Summary of the invention

[0010] The purpose of the present invention is to provide a normally closed sealing structure, a vacuum isolation hatch, and a vacuum pipeline connection method in view of the structural characteristics and existing deficiencies of the existing gate valve technology, as well as the difficulty in large-scale development and in meeting the sealing and switching requirements of magnetic levitation vacuum pipelines, especially the daily need to consume electrical energy to make electric actuators work to achieve a normally closed sealing state, resulting in a very high cost of pipeline use.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is:

[0012] A normally closed sealing structure comprises a box body and a sealing door, wherein a sealing end face and a first driving mechanism are provided in the box body, wherein the sealing door and the first driving mechanism are arranged on a valve plate located in the box body, wherein an end face sealing ring and a spring are provided on the sealing door, wherein two ends of the spring act on the sealing door and the first driving mechanism respectively, wherein the spring is pre-compressed and installed, and wherein the spring force of the spring pushes the sealing door to abut against the sealing end face, wherein the end face sealing ring is tightly attached to the sealing end face, and wherein the first driving mechanism can drive the sealing door to compress the spring and move away from the sealing end face.

[0013] The spring force of the spring can overcome the pressure difference thrust on both sides of the sealing door.

[0014] By adopting the normally closed sealing structure described in the present invention, the first driving mechanism is not required to work. The end face sealing ring is pressed onto the sealing end face only by the spring force provided by the spring, so that the vacuum isolation cabin door is normally closed, which can effectively save the use cost. The first driving mechanism pulls the sealing door to compress the spring, so that the end face sealing ring can be moved away from the sealing end face, so that the seal of the normally closed vacuum isolation cabin door is released, and preparation can be made for the subsequent through-vacuum pipeline. The normally closed sealing structure has a simple principle, is easy to use, and has a good effect.

[0015] Preferably, a plurality of the springs are evenly distributed along the circumference of the sealing door.

[0016] With this structure, the spring forces of several evenly distributed springs act on the circumference of the sealing door, which not only makes the sealing door balanced and prevents deformation, but also provides evenly distributed spring force for the end face sealing ring to press the end face sealing ring against the sealing end face.

[0017] Further preferably, the valve plate is arranged in the box body, on which the pull rod is arranged, the pull rod is connected to the sealing door, the pull rod is outer-connected with a spring guide sleeve, and the spring sleeve is arranged outside the spring guide sleeve.

[0018] With this structure, the pull rod serves as a guide for the spring guide sleeve, and the spring guide sleeve serves as a guide tube for the spring, thereby preventing the spring from undergoing large radial deformation and affecting the stability of the spring force and the service life of the spring.

[0019] Further preferably, the pull rod passes through the rear outer side of the sealing door and is connected to a locking nut and locked.

[0020] Further preferably, the first driving mechanism comprises a plurality of air cylinders or hydraulic cylinders, the air cylinders or hydraulic cylinders are evenly distributed along the circumference of the sealing door, the cylinder bodies of the air cylinders or hydraulic cylinders are connected to the valve plate, and the piston rods of the air cylinders or hydraulic cylinders are connected to the pull rod.

[0021] With this structure, several air cylinders or hydraulic cylinders are evenly distributed around the sealing door, which can provide uniform spring force to the circumferentially pre-compressed spring, thus avoiding deformation of the sealing door end face due to uneven force, affecting the sealing performance and smooth movement of the sealing door.

[0022] Further preferably, one end of the pull rod is connected to the end of the piston rod of the air cylinder or the hydraulic cylinder, and the two ends of the spring act on the sealing door and the cylinder body end of the air cylinder or the hydraulic cylinder respectively.

[0023] With this structure, the pull rod, the spring guide sleeve, the spring and the cylinder or hydraulic cylinder form a single actuator for moving the sealing door, the pull rod is driven by the cylinder or hydraulic cylinder, the spring guide sleeve axially guides the spring and limits the direction of elastic deformation of the spring, the spring pushes the sealing door toward the sealing end face, the end face sealing ring fits with the sealing end face, and the sealing isolation is achieved to realize the normal closure of the cabin door; the cylinder or hydraulic cylinder pulls the sealing door through the pull rod, and the sealing door moves away from the sealing end face until it fits with the valve plate, and the sealing door forms a designed distance with the sealing end face to realize normal opening of the cabin door; the cylinder or hydraulic cylinder uses the same air source or hydraulic oil source to supply air or oil simultaneously through the same pipeline system, which ensures the consistency and stability of the force transmission size and direction of each actuator, and the sealing door is subjected to balanced force along the circumference, and the sealing effect is good.

[0024] Further preferably, a groove body is provided at the end of the piston rod of the air cylinder or the hydraulic cylinder, and the end of the pull rod extends into the groove body and is hinged to the end of the piston rod of the air cylinder or the hydraulic cylinder.

[0025] With this structure, the pull rod has a certain degree of deflection relative to the piston rod of the air cylinder or hydraulic cylinder, making the connection and cooperation of the sealing door more convenient, and the bearing force of the sealing door can be adaptively and evenly distributed on the sealing end surface.

[0026] Further preferably, a pin hole is provided at the end of the piston rod of the air cylinder or hydraulic cylinder at the trough body, and a matching pin hole is provided at the end of the pull rod, and the pin holes are connected by a cylindrical pin.

[0027] Further preferably, the normally closed sealing structure also includes piping, which includes an annular tube and a hose, and the annular tube simultaneously connects all the air cylinders or hydraulic cylinders. The box body is provided with a through-box joint, and the through-box joint is connected to the hose inside and to the air station or hydraulic station outside, and the hose is connected to the annular tube.

[0028] Preferably, the sealing door on which the end face sealing ring is arranged is provided with a stepped positioning groove, and the end face sealing ring is arranged in the stepped positioning groove.

[0029] With this structure, the end face sealing ring is positioned and limited by the stepped positioning groove.

[0030] Further preferably, the inner ring of the end face sealing ring is sleeved on the step surface of the step positioning groove, and the outer ring of the end face sealing ring is matched with a sealing pressure ring.

[0031] With this structure, the sealing pressure ring is used to ensure that the end face sealing ring can work normally and will not be crushed by the sealing end face.

[0032] Further preferably, the end face sealing ring may be a trapezoidal sealing ring, an O-ring or other sealing ring.

[0033] Preferably, a limit sensor is provided on the adjacent surface of the sealing end surface, and the limit sensor is a proximity switch, a limit switch or other position detection sensor.

[0034] With this structure, the limit sensor is used to detect the approach degree of the sealing door, and also prevents the sealing end face and the sealing flange from crushing the end face sealing ring.

[0035] The present invention also provides a normally closed vacuum isolation cabin door, comprising a valve plate and a normally closed sealing structure as described in any one of the above items, end face flanges are provided on both sides of the box body, which are respectively sealed and connected to vacuum pipes, and the two vacuum pipes are coaxially arranged. The valve plate is slidably connected to the box body, and the plate surface of the valve plate can move to or away from between the two vacuum pipes. The first driving mechanism is connected to the valve plate, and the sealing door is connected to the valve plate through the first driving mechanism, and the sealing end face is the inner end face of the box body connecting station.

[0036] The normally closed vacuum isolation door of the present invention can be used to seal and isolate the two vacuum pipes or release the seal through the sealing structure. The sealing structure is set on the valve plate, and the valve plate is slidably connected to the box body, so that the sealing structure can move closer to or farther away from the position between the ends of the two vacuum pipes with the valve plate. When the sealing structure is located between the ends of the two vacuum pipes, the spring force provided by the spring can make the end face sealing ring close to the sealing end face of the end of the vacuum pipe, so as to seal and isolate the two vacuum pipes; when the vacuum isolation door needs to be opened and connected to the two vacuum pipes, the first driving mechanism pulls the sealing door to compress the spring, so that the end face sealing ring is away from the sealing end face, and then the valve plate slides in the box body, and the sealing structure is away from the position between the ends of the two vacuum pipes, so that the two vacuum pipes can be connected, and the internal pressure is consistent. The normally closed vacuum isolation door has a simple structure, is easy to use, and has a good effect.

[0037] Preferably, at least one first through hole is provided on the sealing door, and the first through hole communicates with two sides of the sealing door.

[0038] With this structure, when the vacuum isolation cabin door is in the process of changing from closed to open or from open to closed, the sealing door is connected front to back, and the pressure difference between the two vacuum pipes directly acts on the valve plate instead of on the sealing door, so that the force for opening and closing the sealing door is smaller, that is, the spring with smaller spring force or the first driving mechanism with smaller driving force can push the sealing door, so that the end face sealing ring is close to or away from the sealing end face, which can reduce the cost of the spring and the first driving mechanism.

[0039] Further preferably, the sealing door includes a sealing ring and a sealing flange, the sealing flange is connected to the end of the sealing ring, the sealing ring and the sealing flange form a component with an L-shaped cross-section, the valve plate is provided with a mounting hole for installing the sealing door, the outer ring surface of the sealing ring is slidably connected to the mounting hole, the outer ring surface of the sealing ring is provided with a mounting groove, the mounting groove is provided with a radial sealing ring and a guide ring, and the radial sealing ring is tightly attached to the mounting hole.

[0040] With this structure, the radial sealing ring is used to achieve sealing isolation on both sides of the mounting hole, and the guide ring is used to support the sealing ring in the mounting hole and protect the radial sealing ring.

[0041] Further preferably, the sealing ring and the sealing flange are integrally formed components.

[0042] Further preferably, the guide rings are provided on both sides of the radial sealing ring.

[0043] Further preferably, the guide ring is a slippery and wear-resistant part.

[0044] Further preferably, the guide ring is a polytetrafluoroethylene plate.

[0045] Further preferably, a grid structure is connected inside the sealing ring, and the first through hole is arranged on the grid structure.

[0046] With this structure, the grid structure enhances the rigidity of the sealing ring, making it difficult for the sealing door to deform, achieving a good sealing effect, and saving materials for manufacturing the sealing door.

[0047] Preferably, the top and bottom of the valve plate are respectively provided with protrusions, a slide groove is provided in the box body, and the protrusion is arranged in the slide groove to form a sliding guide pair.

[0048] With this structure, the protrusion on the valve plate cooperates with the slide groove in the box body to form a sliding guide pair, which has safe and reliable guidance, high axial positioning accuracy, and bears the axial sealing force of the spring and the pressure difference thrust of the vacuum pipe, avoiding the problems of small axial bearing force and low positioning accuracy of the wheel guide device used in the prior art.

[0049] Further preferably, the slide groove is U-shaped.

[0050] Further preferably, the slide groove is arranged along the length direction of the box body.

[0051] Further preferably, the convex portion of the convex block has three working surfaces, each of the working surfaces is provided with a group of slide plates, each group of the slide plates includes a plurality of slide plates, and the slide plates are fitted in the slide grooves.

[0052] Further preferably, the slide plates are evenly arranged.

[0053] Further preferably, the slide plate is mounted on the protrusion via a fastener.

[0054] Further preferably, the slide plate is a wear-resistant lubricating lining.

[0055] Further preferably, the slide plate is a self-lubricating wear-resistant lining plate.

[0056] Preferably, the normally closed vacuum isolation cabin door also includes a second driving mechanism, which is a screw system, an oil cylinder system, an air cylinder system, a pulley system, a gear rack system or a sprocket chain system, etc. The fixed parts of the screw system, the oil cylinder system, the air cylinder system, the pulley system, the gear rack system or the sprocket chain system are connected to the box body, and the moving parts of the screw system, the oil cylinder system, the air cylinder system, the pulley system, the gear rack system or the sprocket chain system are connected to the valve plate.

[0057] Further preferably, the screw system includes a screw and a driver, the driver is located outside the box body and sealed and fixed on the box body, the screw is connected to the box body, the driver is connected to one end of the screw and can drive the screw to rotate, the screw is threadedly connected with a screw nut, the screw nut is connected to the valve plate, and the screw is arranged along the sliding direction of the valve plate.

[0058] With this structure, the driver rotates to drive the lead screw to rotate, and the lead screw rotation drives the lead screw nut to reciprocate along the lead screw in a straight line, thereby driving the valve plate to slide in the box.

[0059] Further preferably, the driver is connected to one end of the lead screw via a coupling, and the other end of the lead screw is connected to the rotary encoder via a coupling.

[0060] Further preferably, the lead screw is installed in the housing through two lead screw bearing seats, and the lead screw bearing seats support the lead screw.

[0061] Further preferably, the screw nut is connected to the nut bearing seat, and the nut bearing seat is connected to the valve plate.

[0062] Further preferably, the driver is a motor.

[0063] Further preferably, the screw system further comprises a rotary encoder, wherein the rotary encoder is connected inside the housing, and the rotary encoder is connected to the other end of the screw.

[0064] With this structure, the rotary encoder measures the angular displacement or angular velocity of the lead screw, and controls the moving distance of the lead screw nut in conjunction with the pitch of the lead screw, thereby being able to precisely control the moving distance and accurate positioning of the valve plate.

[0065] Preferably, the box body comprises a front half box body, a rear half box body and an end cover, the front half box body and the rear half box body are sealingly connected, a box body seal is arranged on the joint surface, the same end of the front half box body and the rear half box body is sealingly connected to the end cover, and an end cover seal is arranged on the joint surface.

[0066] Further preferably, the box body seal and the end cover seal may be strip seals or plate seals or the like.

[0067] Further preferably, stoppers are used for positioning between the mating surfaces of the front half box, the rear half box and the end cover.

[0068] Preferably, the box body is provided with three independent workstations in sequence, the workstation in the middle is a box body connecting workstation connected to the vacuum pipe, both sides of the box body connecting workstation are respectively stay workstations for accommodating the valve plate, the box body connecting workstations are distributed on the front and back sides of the box body and are coaxially arranged, the box body connecting workstations are round tubes with the same inner diameter as the vacuum pipe, and the sealing end face is arranged on the side of the box body connecting workstation facing the valve plate.

[0069] Further preferably, a box mounting platform is provided at the bottom of the circular tube of the box connecting station, and the box mounting platform is used to install the magnetic levitation motor bracket.

[0070] Further preferably, the valve plate is provided with two independent workstations in sequence, the left side is a valve plate sealing workstation, and the right side is a valve plate connecting workstation, the valve plate connecting workstation is a round tube with the same inner diameter as the box connecting workstation, and the valve plate sealing workstation is provided with the sealing door.

[0071] In an initial state, the valve plate sealing station is aligned with the box body connecting station.

[0072] With this structure, the valve plate moves once in the box body, so that the valve plate sealing position is moved away from the box body connecting position, and the valve plate connecting position is aligned with the box body connecting position, so that the two vacuum pipes are connected. Similarly, when resetting, the valve plate connecting position is moved away from the box body connecting position, and the valve plate sealing position is aligned with the box body connecting position, so that the two vacuum pipes are sealed and disconnected.

[0073] Further preferably, a valve plate mounting platform is provided at the bottom of the circular tube of the valve plate connecting station, and the valve plate mounting platform is used for mounting the magnetic suspension motor bracket.

[0074] The present invention also provides a bidirectional normally closed vacuum isolation cabin door, including a normally closed vacuum isolation cabin door as described in any of the above items, wherein two sets of normally closed sealing structures as described in any of the above items are provided on the valve plate, and the two sealing doors are respectively located on both sides of the valve plate, and the two sealing doors are respectively used to seal the corresponding vacuum pipes.

[0075] By adopting the bidirectional normally closed vacuum isolation cabin door described in the present invention, the two vacuum pipes connected to the box body are sealed separately by two sets of sealing structures, which has better sealing performance. When a single set of the sealing structures has problems and causes the seal to fail, the other set of the sealing structures can still effectively seal and separate the two adjacent vacuum pipes, thereby providing a reliable vacuum environment for the vacuum pipeline system. In addition, the spring forces of the springs in the two sets of the sealing structures or the driving forces of the first driving mechanisms are in opposite directions, and the spring forces acting on the valve plate or the driving forces of the first driving mechanisms can offset each other well, so that the axial thrust on the sliding guide pair of the valve plate and the box body is greatly reduced or even eliminated. The vacuum isolation cabin door has a simple structure, is easy to use, and has a good effect.

[0076] The present invention also provides a normally closed vacuum pipe connection method, using the normally closed vacuum isolation door as described in any one of the above or the bidirectional normally closed vacuum isolation door as described, the method comprising:

[0077] The first driving mechanism pulls the sealing door to overcome the spring force of the spring, the end face sealing ring is pulled away from the sealing end face, and the seal between the two vacuum pipes on both sides of the box body is released and there is no pressure difference;

[0078] After the seal is released, the valve plate slides in the box, the valve plate and the sealing door are away from between the two vacuum pipes, and the two vacuum pipes are connected.

[0079] By adopting the normally closed vacuum pipeline connection method described in the present invention, the pressure of the cylinder or hydraulic cylinder can be individually adjusted according to the different vacuum degrees of the pipeline to meet the different vacuum degree requirements of the pipeline; this method has simple steps, easy operation, few action steps, can respond quickly, and has good effect.

[0080] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0081] 1. The normally closed sealing structure of the present invention does not require the first driving mechanism to work. The end face sealing ring is pressed against the sealing end face only by the spring force provided by the spring, so as to realize the normally closed state of the vacuum isolation door, which can effectively save the use cost. The first driving mechanism pulls the sealing door to compress the spring, so that the end face sealing ring is separated from the sealing end face, so that the normally closed vacuum isolation door is released from the seal, and it can prepare for the subsequent through-hole vacuum pipeline. The normally closed sealing structure has a simple principle, is easy to use, and has a good effect.

[0082] 2. A normally closed vacuum isolation door according to the present invention can seal and isolate two vacuum pipes or release the seal through the sealing structure. The sealing structure is arranged on the valve plate, and the valve plate is slidably connected to the box body, so that the sealing structure can approach or move away from the position between the ends of the two vacuum pipes along with the valve plate. When the sealing structure is located between the ends of the two vacuum pipes, the spring force provided by the spring can make the end face sealing ring close to the sealing end face of the end of the vacuum pipe to seal and isolate the two vacuum pipes. When the vacuum isolation door needs to be opened to connect the two vacuum pipes, the first driving mechanism pulls the sealing door to compress the spring, so that the end face sealing ring moves away from the sealing end face, and then the valve plate slides in the box body, and the sealing structure moves away from the position between the ends of the two vacuum pipes. The two vacuum pipes can be connected and the internal pressure is consistent. The normally closed vacuum isolation door has a simple structure, is easy to use, and has a good effect.

[0083] 3. A normally closed vacuum isolation door of the present invention is preferably provided with at least one first through hole on the sealing door, wherein the first through hole is connected to both sides of the sealing door, and the sealing door is connected front to back during the process of the vacuum isolation door from closing to opening or from opening to closing, and the pressure difference between the two vacuum pipes directly acts on the valve plate instead of on the sealing door, so that the force for opening and closing the sealing door is relatively small, that is, the spring with a relatively small spring force or the first driving mechanism with a relatively small driving force can be used to push the sealing door, so that the end face sealing ring is close to or away from the sealing end face, and the cost of the spring and the first driving mechanism can be reduced;

[0084] 4. In a preferred normally closed vacuum isolation door of the present invention, the protrusion on the valve plate cooperates with the slide groove in the box body to form a sliding guide pair, which is safe and reliable in guiding, has high axial positioning accuracy, and bears the axial sealing force of the spring and the pressure difference thrust of the vacuum pipe, thus avoiding the problem of small axial bearing force and low positioning accuracy of the wheel guide device used in the prior art;

[0085] 5. The bidirectional normally closed vacuum isolation door of the present invention has better sealing performance, and when a single set of the sealing structure fails due to a problem, the other set of the sealing structure can still effectively seal and separate the two adjacent vacuum pipes, thereby providing a reliable vacuum environment for the vacuum pipeline system; in addition, the spring forces of the springs or the driving forces of the first driving mechanism in the two sets of the sealing structures are in opposite directions, and the spring forces acting on the valve plate or the driving forces of the first driving mechanism can offset each other well, so that the axial thrust of the sliding guide pair matched with the valve plate and the box is greatly reduced or even eliminated. The vacuum isolation door has a simple structure, is easy to use, and has a good effect;

[0086] 6. In the normally closed vacuum pipe connection method described in the present invention, the pressure of the air cylinder or hydraulic cylinder can be individually adjusted according to the different vacuum degrees of the pipe to meet the different vacuum degree requirements of the pipe; the method has simple steps, easy operation, few action steps, can respond quickly, and has good effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] Figure 1 It is a schematic diagram of the cross-sectional structure of a one-way normally closed vacuum isolation cabin door in a normally closed state;

[0088] Figure 2 It is a schematic diagram of the cross-sectional structure of a one-way normally closed vacuum isolation cabin door in an open state;

[0089] Figure 3 It is a schematic diagram of the top view of the structure of a one-way normally closed vacuum isolation cabin door;

[0090] Figure 4 for Figure 1 Schematic diagram of the cross-sectional structure of AA;

[0091] Figure 5 for Figure 4 The enlarged structural diagram of the middle D part;

[0092] Figure 6 for Figure 2 Schematic diagram of the cross-sectional structure of the middle BB;

[0093] Figure 7 for Figure 2 Schematic diagram of the cross-sectional structure of the CC;

[0094] Figure 8 It is a schematic diagram of the longitudinal section structure of the bidirectional normally closed vacuum isolation cabin door in the normally closed state;

[0095] Fig. 9 for Figure 8 Schematic diagram of the enlarged structure of part E in the middle.

[0096] Markings in the figure: 01-vacuum pipe, 1-box, 11-front half box, 12-rear half box, 13-end cover, 14-box seal, 15-end cover seal, 16-box connecting station, 17-box mounting table, 18-slide, 19-sealing end face, 191-limit sensor, 2-valve plate, 21-valve plate sealing station, 211-annular pipe, 22-valve plate connecting station, 23-sealing door, 231-first through hole, 232-radial sealing ring, 2 33-guide ring, 234-end face sealing ring, 235-sealing pressure ring, 24-bump, 241-slide plate, 25-cylinder or hydraulic cylinder, 26-pull rod, 261-locking nut, 262-cylindrical pin, 27-spring, 28-spring guide sleeve, 29-valve plate mounting table, 3-second drive mechanism, 31-screw, 32-driver, 33-screw bearing seat, 34-nut bearing seat, 35-rotary encoder, 4-piping, 41-circular tube, 42-hose. DETAILED DESCRIPTION

[0097] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0098] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0099] Example 1

[0100] like Figures 1 to 7As shown, a normally closed vacuum isolation cabin door described in the present invention includes a box body 1, a valve plate 2, a second driving mechanism 3 and a pipe 4.

[0101] like Figures 1 to 3 As shown, the box body 1 includes a front half box body 11, a rear half box body 12 and an end cover 13. The front half box body 11 and the rear half box body 12 are combined to form a right box body through a stopper, a joint surface and bolts. A sealing groove is processed on the joint surface, and a box body seal 14 is installed therein. The left end surface of the right box body is processed with a stopper and a joint surface for positioning with the end cover 13. The right box body and the end cover 13 are connected by bolts. A sealing groove is processed on the joint surface, and an end cover seal 15 is installed therein. The front half box body 11 and the rear half box body 12 are respectively connected to a vacuum pipe 01, and the two vacuum pipes 01 are aligned. The box body seal 14 and the end cover seal 15 can be either a sealing strip, or other seals such as an "O"-shaped sealing ring, a plate-type sealing gasket, etc.

[0102] like Figures 1 to 3 As shown, the box body 1 is provided with three independent workstations, the middle workstation is the box body connecting workstation 16, and the left and right workstations are stop workstations for accommodating the valve plate 2. The box body connecting workstations 16 are distributed on the front and rear sides of the box body 1, that is, one box body connecting workstation 16 is provided on the front half box body 11 and the rear half box body 12 respectively, and the box body connecting workstation 16 is a circular tube with the same inner diameter as the vacuum pipe 01, and the two box body connecting workstations 16 are oppositely and coaxially arranged.

[0103] like Figure 4 As shown, both ends of the box connecting station 16 are provided with flanges, the flange facing the outside of the box 1 is sealed and connected to the corresponding vacuum pipe 01, an installation space for the valve plate 2 is provided between the flanges facing the inside of the box 1, and the flange surface of the flange facing the inside of the box 1 serves as a sealing end surface 19, and a limit sensor 191 is provided on the adjacent surface of the sealing end surface 19, the limit sensor 191 can be a proximity switch, a limit switch or other position detection sensor, and a proximity switch is used in this embodiment, and the adjacent surface can be the inner ring surface of the flange or the outer ring surface of the flange.

[0104] like Figure 7 As shown, a box mounting platform 17 is provided at the bottom of the circular tube of the box connecting station 16, and the box mounting platform 17 is used to install the magnetic suspension motor bracket.

[0105] like Figure 1 , Figure 2 , Figures 4 to 7As shown, the inner top surface and the inner bottom surface of the box body 1 are respectively provided with slide grooves 18 from left to right, that is, the slide grooves 18 are arranged along the length direction of the front half box body 11 and the rear half box body 12, and the slide grooves 18 are U-shaped.

[0106] like Figure 1 and Figure 2 As shown, the valve plate 2 is provided with two independent stations, the left side is the valve plate sealing station 21, and the right side is the valve plate connecting station 22. The valve plate connecting station 22 is a round tube with the same inner diameter as the box connecting station 16. A valve plate mounting platform 29 is provided at the bottom of the round tube of the valve plate connecting station 22. The valve plate mounting platform 29 is used to install the magnetic levitation motor bracket. A sealing door 23 is provided at the valve plate sealing station 21. The sealing door 23 on the valve plate 2 and the sealing end face 19 on the box 1 cooperate with each other to form a sealing structure.

[0107] like Figure 4 and Figure 5 As shown, the sealing door 23 includes a sealing ring and a sealing flange, and the sealing flange is connected to the end of the sealing ring. Preferably, the sealing ring and the sealing flange are integrally formed components, and the sealing ring and the sealing flange form a component with an L-shaped cross-section. The valve plate sealing station 21 is formed by welding an annular tube 211 with an internal web and rib plate and an external web and rib plate, and is an integral structure with the valve plate 2. A mounting hole for mounting the sealing door 23 is provided in the annular tube 211, and the outer annular surface of the sealing ring is slidably connected to the mounting hole. The outer annular surface of the sealing ring is A mounting groove for a radial sealing ring 232 and a guide ring 233 is provided on the top, the radial sealing ring 232 is installed in the middle groove, and the two guide rings 233 are respectively installed in the mounting grooves on both sides of the radial sealing ring 232, the radial sealing ring 232 is tightly attached to the mounting hole, and the guide ring 233 is a slippery and wear-resistant part. In this embodiment, a polytetrafluoroethylene plate is used, and the sealing isolation on both sides of the mounting hole is achieved through the radial sealing ring 232, and the sealing ring is supported in the mounting hole through the guide ring 233 and protects the radial sealing ring 232.

[0108] like Figure 5 As shown, there is a grid structure inside the sealing ring, and the grid structure enhances the rigidity of the sealing ring, so that the sealing door 23 is not easily deformed and has a good sealing effect, and also saves materials for manufacturing the sealing door 23. At least one first through hole 231 is provided on the grid structure, and the first through hole 231 connects the front and rear sides of the sealing door 23, so that the sealing door 23 is connected front to back, avoiding the force generated by the pressure difference on both sides when the front and back are not connected directly acting on the sealing door 23, resulting in a greatly increased force required for opening and closing the sealing door 23, and an increase in manufacturing cost.

[0109] like Figure 4 and Figure 5 As shown, the sealing flange is located between the mounting hole and the sealing end face 19, and a step positioning groove is provided on the side of the sealing flange facing the sealing end face 19, and an end face sealing ring 234 and a sealing pressure ring 235 are provided in the step positioning groove, and the inner ring of the end face sealing ring 234 is sleeved on the step surface of the step positioning groove, and the sealing pressure ring 235 is pressed on the outer ring of the end face sealing ring 234, and the sealing pressure ring 235 is used to ensure that the end face sealing ring 234 can work normally and is not crushed by the sealing end face 19, and the limit sensor 191 is used to detect the proximity of the sealing door 23, and this embodiment also prevents the sealing end face 19 and the sealing flange from crushing the end face sealing ring 234.

[0110] like Figure 4 and Figure 5 As shown, the valve plate 2 is provided with a second driving mechanism, which includes a plurality of cylinders or hydraulic cylinders 25, and the cylinders or hydraulic cylinders 25 are evenly arranged along the circumference of the sealing door 23, as shown in FIG. Figure 1 and Figure 2 As shown, in this embodiment, 12 cylinders or hydraulic cylinders 25 are evenly distributed, and a mounting stop is provided on the valve plate 2. The cylinder or hydraulic cylinder 25 is fixedly connected to the valve plate 2 by bolts and the mounting stop. The piston rod end of the cylinder or hydraulic cylinder 25 is processed with a groove body and a pin hole, and the end of the pull rod 26 is inserted into the groove body. The end of the pull rod 26 is provided with a head and a pin hole matching the piston rod end of the cylinder or hydraulic cylinder 25. A cylindrical pin 262 is inserted into the pin hole, and the cylindrical pin 262 passes through the head of the pull rod 26, so that the head of the pull rod 26 is hinged to the piston rod end of the cylinder or hydraulic cylinder 25, and the sealing flange is provided with a The corresponding second through hole, the other end of the pull rod 26 passes through the corresponding second through hole and is connected with a locking nut 261. The cylinder or hydraulic cylinder 25 pulls the pull rod 26, and the pull rod 26 pulls the sealing door 23 through the locking nut 261. The pull rod 26 is outer-connected with a spring guide sleeve 28, and the spring guide sleeve 28 is outer-connected with a spring 27. The spring 27 is pre-compressed and installed, and the two ends of the spring 27 respectively abut against the sealing flange and the cylinder end of the cylinder or hydraulic cylinder 25. The sealing flange moves to the right under the action of the pull rod 26 and stops when it abuts against the left end face of the mounting hole of the sealing door 23. At this time, the spring guide sleeve 28 can move axially.

[0111] like Figure 1 , Figure 2 , Figures 4 to 7As shown, the top and bottom of the valve plate 2 are respectively provided with protrusions 24, and the protrusions 24 are installed in cooperation with the mounting grooves on the valve plate 2 through fasteners. The convex part of the protrusion 24 has three working surfaces, and each of the working surfaces is provided with a group of slide plates 241. Each group of the slide plates 241 includes a plurality of slide plates 241, and the slide plates 241 are evenly arranged and installed on the protrusions 24 through fasteners. The protrusions 24 are arranged in the slide grooves 18 to form a sliding guide pair. The slide plates 241 fit in the slide grooves 18. Through the cooperation of the protrusions 24 and the slide grooves 18, the valve plate 2 and the box body 1 are slidably connected. The slide plates 241 are wear-resistant and lubricating linings. In this embodiment, self-lubricating wear-resistant linings are used. When maintaining the valve plate 2, it is only necessary to open the end cover 13 and pull the valve plate 2 out from one side of the end cover 13 along the slide groove 18, which is very convenient.

[0112] like Figures 1 to 4 , Figure 6 , Figure 7 As shown, the second driving mechanism 3 includes a lead screw 31, a driver 32, a lead screw bearing seat 33, a nut bearing seat 34, and a rotary encoder 35. The driver 32 is located outside the end cover 13 and is sealed and fixed on the box body 1. The driver 32 is connected to one end of the lead screw 31 through a coupling, and the other end of the lead screw 31 is connected to the rotary encoder 35 through a coupling. The lead screw 31 is installed in the box body 1 through two lead screw bearing seats 33. The lead screw 31 extends from the stop station of the box body 1 to the box body connecting station 16. The lead screw bearing seat 33 supports the lead screw 31. The lead screw 31 is threadedly connected with a lead screw nut, and the lead screw nut is connected to the nut bearing seat 34. The nut bearing seat 34 is connected to the valve plate 2, and the driver 32 is a motor. The rotation of the motor drives the lead screw 31 to rotate. The rotation of the lead screw 31 drives the lead screw nut to reciprocate along the lead screw 31 in a straight line, thereby driving the valve plate 2 to slide in the box body 1. The rotary encoder 35 measures the angular displacement or angular velocity of the rotation of the lead screw 31, and controls the moving distance of the lead screw nut in combination with the pitch of the lead screw 31, so as to accurately control the moving distance and accurate positioning of the valve plate 2, so as to realize that the valve plate connecting station 22 and the valve plate sealing station 21 can be accurately aligned with the box connecting station 16 respectively, so that the valve plate 2 closes or conducts the vacuum pipe 01.

[0113] In some specific embodiments, the second driving mechanism 3 is a cylinder system, which includes a driving cylinder, a cylinder body of the driving cylinder is hingedly connected to the box body 1, and a telescopic rod of the driving cylinder is hingedly connected to the valve plate 2. The driving cylinder is a servo cylinder or a cylinder with a built-in linear displacement sensor or a cylinder with a built-in pull-wire displacement sensor, etc., which can accurately control the stroke of the cylinder telescopic rod to achieve accurate control of the position of the valve plate 2 in the box body 1; a linear displacement sensor can also be directly arranged between the box body 1 and the valve plate 2 to accurately detect and control the position of the valve plate 2; ensuring that the valve plate connecting station 22 and the valve plate sealing station 21 can be accurately aligned with the box body connecting station 16 respectively.

[0114] In some specific embodiments, the second driving mechanism 3 is a cylinder system, which includes a driving cylinder, a cylinder body of the driving cylinder is hingedly connected to the box body 1, and a telescopic rod of the driving cylinder is hingedly connected to the valve plate 2. The driving cylinder is a servo cylinder or a cylinder with a built-in linear displacement sensor or a cylinder with a built-in pull-wire displacement sensor, etc., which can accurately control the stroke of the cylinder telescopic rod to achieve accurate control of the position of the valve plate 2 in the box body 1; a linear displacement sensor can also be directly arranged between the box body 1 and the valve plate 2 to accurately detect and control the position of the valve plate 2; ensuring that the valve plate connecting station 22 and the valve plate sealing station 21 can be accurately aligned with the box body connecting station 16 respectively.

[0115] In some specific embodiments, the second driving mechanism 3 is a pulley system, which includes a driving wheel, a driven wheel and a belt, the belt is connected to the driving wheel and the driven wheel, the driving wheel and the driven wheel are connected to the box body 1, the belt is connected to the valve plate 2, the shaft of the driving wheel is connected to the motor and the rotary encoder through a coupling, and the rotary encoder is used to detect and control the position of the valve plate 2; a linear displacement sensor can also be directly arranged between the box body 1 and the valve plate 2 to accurately detect and control the position of the valve plate 2; ensure that the valve plate connecting station 22 and the valve plate sealing station 21 can be accurately aligned with the box body connecting station 16 respectively.

[0116] In some specific embodiments, the second driving mechanism 3 is a gear rack system, which includes a gear and a rack meshing therewith, the gear is connected to the housing 1, the rack is connected to the valve plate 2, the shaft of the gear is connected to the motor and the rotary encoder through a coupling, and the rotary encoder is used to detect and control the position of the valve plate 2; a linear displacement sensor can also be directly arranged between the housing 1 and the valve plate 2 to accurately detect and control the position of the valve plate 2; and ensure that the valve plate connecting station 22 and the valve plate sealing station 21 can be accurately aligned with the housing connecting station 16 respectively.

[0117] In some specific embodiments, the second driving mechanism 3 is a sprocket chain system, which includes a sprocket and a chain matching therewith, the sprocket is connected to the box body 1, the chain is connected to the valve plate 2, the shaft of the sprocket is connected to the motor and the rotary encoder through a coupling, and the rotary encoder is used to detect and control the position of the valve plate 2; a linear displacement sensor can also be directly arranged between the box body 1 and the valve plate 2 to accurately detect and control the position of the valve plate 2; to ensure that the valve plate connecting station 22 and the valve plate sealing station 21 can be accurately aligned with the box body connecting station 16 respectively.

[0118] like Figure 1 and Figure 6 As shown, the piping 4 includes a circular tube 41 and a hose 42. The circular tube 41 is connected to all the air cylinders or hydraulic cylinders 25 at the same time through a pipe joint. A through-box joint is provided on the box body 1. The through-box joint is connected to the hose 42 inside and to the pipe from the air station or hydraulic station outside. The hose 42 is connected to the circular tube 41.

[0119] The normally closed vacuum isolation door, such as Figure 1 , Figure 4 and Figure 5 As shown, under normal circumstances, the valve plate sealing station 21 is aligned with the box connecting station 16, and under the action of the spring force of the spring 27, the sealing door 23 is pushed away from the valve plate 2, and the end face sealing ring 234 is pressed against the sealing end face 19, so that the front and rear of the box 1 are sealed and isolated, that is, the front and rear vacuum pipes 01 are isolated and in a normally closed state; when it is necessary to connect the front and rear vacuum pipes 01, the cylinder or hydraulic cylinder 25 is actuated, and the sealing door 23 is pulled toward the valve plate 2 through the piston rod of the cylinder or hydraulic cylinder 25 and the pull rod 26, the spring 27 is compressed, the sealing door 23 abuts against the pipe end of the annular tube 211, and the end face sealing ring 234 is away from the sealing end face 19, so that the front and rear sealing of the box 1 is released, and then the second driving mechanism 3 drives the valve plate 2 to slide in the box 1, so that the valve plate sealing station 21 moves to the stop position in the box 1, as shown in FIG. Figure 2 and Figure 7 As shown, at the same time, the valve plate connecting station 22 moves toward the box connecting station 16 and is aligned, so that the front and rear vacuum pipes 01 are connected and in an open state.

[0120] The beneficial effects of the normally closed vacuum isolation door described in this embodiment are:

[0121] 1. By setting three independent workstations in the box body 1 and two independent workstations on the valve plate 2, the valve plate 2 is set in the box body 1 as a whole, and the end cover 13, the front half box body 11, and the rear half box body 12 of the box body 1 are positioned by stoppers, and the box body seal 14 and the end cover seal 15 are sealed, thereby ensuring the sealing performance of the vacuum isolation hatch and providing a reliable vacuum environment for the vacuum pipeline system;

[0122] 2. When the valve plate 2 is maintained, it is only necessary to open the end cover 13 and pull the valve plate 2 out from one side of the end cover 13 along the slide groove 18, which is very convenient for maintenance;

[0123] 3. Two independent stations are set on the valve plate 2. The valve plate 2 is driven to move back and forth by the second driving mechanism 3 to realize the reliable switching of the valve plate sealing station 21 and the valve plate communication station 22, and complete the communication and sealing closure with the box body communication station 16;

[0124] 4. The first driving mechanism does not need to work, and the end face sealing ring 234 is pressed against the sealing end face 19 only by the spring force provided by the spring 27, so that the vacuum isolation door is normally closed, which can effectively save the use cost;

[0125] 5. The protrusion 24 on the valve plate 2 cooperates with the slide groove 18 in the box body 1 to form a sliding guide pair, which is safe and reliable in guidance, has high axial positioning accuracy, and bears the axial sealing force of the spring 27 and the pressure difference thrust of the vacuum pipe 01, avoiding the problems of small axial bearing force and low positioning accuracy of the wheel-type guide device used in the prior art;

[0126] 6. The first driving mechanism uses a plurality of the air cylinders or hydraulic cylinders 25, which are evenly arranged along the circumference of the sealing door 23. The sealing force on the end face sealing ring 234 is even along the entire circumference, and the sealing is safe and reliable;

[0127] 7. The distribution circle diameter and configuration quantity of the air cylinder or hydraulic cylinder 25 can be set according to the diameter of the vacuum pipeline 01 and the needs, and is suitable for large and super large vacuum pipeline systems;

[0128] 8. The middle part of the sealing door 23 is designed as a grid structure. Firstly, the rigidity of the sealing door 23 is enhanced, deformation is not easy to occur, and the sealing effect is good. Secondly, the sealing door 23 is connected from front to back through the first through hole 231. The sealing of the sealing door 23 to the box connecting station 16 can be achieved only by the spring force of the spring 27, which avoids the force generated by the pressure difference on both sides when the front and back are not connected directly to the sealing door 23. Therefore, it can avoid the increase of the force required for opening and closing the sealing door 23, which requires the increase of the spring force provided by the spring 27 and the driving force of the cylinder or hydraulic cylinder 25, and the increase of manufacturing cost, and it can also avoid the increase of the force on the end face sealing ring 234 and the sealing door 23 and other parts, which requires the increase or strengthening of their rigidity and strength, and the increase of manufacturing cost.

[0129] The normally closed vacuum isolation cabin door has a simple structure, is easy to use and has a good effect.

[0130] Example 2

[0131] like Figure 8 and Fig. 9 As shown, a vacuum isolation cabin door described in the present invention is a bidirectional normally closed vacuum isolation cabin door, which is different from Example 1 in that, in this embodiment, two sets of the sealing structures are provided on the valve plate 2, and the two sealing doors 23 are respectively located on both sides of the valve plate sealing station 21, and the two sealing doors 23 are respectively used to seal the box connecting station 16 of the front half box 11 and the box connecting station 16 of the rear half box 12.

[0132] The bidirectional normally closed vacuum isolation door described in this embodiment has the following beneficial effects in addition to the beneficial effects of embodiment 1:

[0133] 1. The two box connecting stations 16 of the box 1 are sealed separately by two sets of the sealing structures, which have better sealing performance. In the case that a single set of the sealing structure has problems and causes sealing failure, the other set of the sealing structure can still effectively seal and separate the two adjacent vacuum pipes 01, providing a reliable vacuum environment for the vacuum pipeline system;

[0134] 2. The spring forces of the springs 27 in the two sets of the sealing structures are opposite, and the spring forces acting on the valve plate 2 can offset each other well, so that the axial thrust of the sliding guide pair composed of the protrusion 24 and the slide groove 18 is greatly reduced or even eliminated, which can effectively reduce the design and manufacturing costs and extend the service life.

[0135] The vacuum isolation cabin door has a simple structure, is easy to use and has a good effect.

[0136] Example 3

[0137] like Figures 1 to 9 As shown, a normally closed vacuum pipe connection method described in the present invention uses a normally closed vacuum isolation door as described in Example 1 or Example 2, the vacuum pipe 01 on one side of the vacuum isolation door is in a vacuum state, and the vacuum pipe 01 on the other side is in a non-vacuum state, and there is a pressure difference on both sides. The method includes the following steps:

[0138] The action of the air cylinder or hydraulic cylinder 25 overcomes the spring force of the spring 27, and the sealing door 23 is pulled close to the annular tube 211 and away from the sealing end face 19 through the piston rod of the air cylinder or hydraulic cylinder 25 and the pull rod 26. The spring 27 is compressed, and the end face sealing ring 234 is released from contact with the sealing end face 19. The sealing ring slides in the mounting hole until the sealing flange abuts against the end face of the annular tube 211, so that the vacuum pipe 01 on both sides of the vacuum isolation cabin door is released from sealing until the pressure in the vacuum pipe 01 is consistent.

[0139] The driver 32 drives the lead screw 31 to rotate, and the rotation of the lead screw 31 drives the lead screw nut to move linearly from right to left, thereby driving the valve plate 2 to move from right to left along the slide groove 18 in the box body 1. Figure 1 and Figure 2 As shown, the valve plate sealing station 21 enters the stop station of the box body 1, and the valve plate connecting station 22 is aligned with the box body connecting station 16, so that the vacuum pipes 01 on both sides of the vacuum isolation cabin door are connected to meet the passage of the maglev train.

[0140] The vacuum pipe connection method described in this embodiment overcomes the spring force of the spring 27 through the action of the air cylinder or hydraulic cylinder 25, so that the spring force of the end face sealing ring 234 pressing against the sealing end face 19 is released, the seal of the vacuum pipe 01 is released, and the internal pressure is consistent. Since the first through hole 231 is provided on the sealing door 23, there is no pressure difference on both sides of the sealing door 23. The pressure difference of the vacuum pipe 01 acts on the valve plate 2 and is then transmitted to the connection between the valve plate 2 and the box body 1, that is, the sliding guide pair. The sliding guide pair is composed of the protrusion 24 and the slide groove 18, and has high axial positioning accuracy. It can well bear the axial thrust and pressure difference thrust of the spring 27; then the valve plate 2 is driven by the driver 32 to slide in the box body 1, so that the valve plate sealing station 21 leaves the box body connection station 16, the valve plate connection station 22 is aligned with the box body connection station 16, and the vacuum pipe 01 is connected. The method has simple steps, convenient operation, few action steps, can respond quickly, and has good effect.

[0141] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A normally closed sealing structure, comprising a box body (1) and a sealing door (23), characterized in that: The housing (1) is provided with a sealing end face (19) and a first driving mechanism. The sealing door (23) and the first driving mechanism are arranged on the valve plate (2) and are located in the housing (1). The sealing door (23) is provided with an end face sealing ring (234) and a spring (27). The two ends of the spring (27) act on the sealing door (23) and the first driving mechanism respectively. The spring (27) is pre-compressed and installed. The spring force of the spring (27) causes the end face sealing ring (234) to be tightly attached to the sealing end face (19). The first driving mechanism can drive the sealing door (23) to compress the spring (27) and move away from the sealing end face (19). The sealing door (23) is arranged on the valve plate (2), and a plurality of springs (27) are evenly distributed around the sealing door (23). A pull rod (26) corresponding to the spring (27) is evenly distributed around the sealing door (23). The pull rod (26) is connected to the sealing door (23). A spring guide sleeve (28) is connected to the outer surface of the pull rod (26). The spring (27) is sleeved outside the spring guide sleeve (28). The first driving mechanism comprises a plurality of cylinders or hydraulic cylinders (25) corresponding to the pull rod (26). The cylinder body of the cylinder or hydraulic cylinder (25) is connected to the valve plate (2), the piston rod of the cylinder or hydraulic cylinder (25) is connected to the pull rod (26), one end of the pull rod (26) is connected to the piston rod end of the cylinder or hydraulic cylinder (25), and the two ends of the spring (27) act on the sealing door (23) and the cylinder body end of the cylinder or hydraulic cylinder (25) respectively. The sealing door (23) is provided with a stepped positioning groove on the side facing the sealing end face (19), the end face sealing ring (234) is installed in the stepped positioning groove, the inner ring of the end face sealing ring (234) is sleeved on the stepped surface of the stepped positioning groove, and the outer ring of the end face sealing ring (234) is matched with a sealing pressure ring (235).

2. The normally closed sealing structure according to claim 1, characterized in that: The end of the piston rod of the air cylinder or hydraulic cylinder (25) is provided with a groove body, and the end of the pull rod (26) extends into the groove body and is hinged to the end of the piston rod of the air cylinder or hydraulic cylinder (25).

3. The normally closed sealing structure according to claim 1, characterized in that: The invention also comprises a piping (4), wherein the piping (4) comprises a circular tube (41) and a hose (42), wherein the circular tube (41) is connected to all the air cylinders or hydraulic cylinders (25) at the same time, and the box body (1) is provided with a box-penetrating joint, wherein the box-penetrating joint is connected to the hose (42) inside and to the air station or hydraulic station outside, and the hose (42) is connected to the circular tube (41).

4. The normally closed sealing structure according to claim 1, characterized in that: The end face sealing ring (234) is a trapezoidal sealing ring, an O-shaped sealing ring or other sealing rings.

5. The normally closed sealing structure according to any one of claims 1 to 4, characterized in that: A limit sensor (191) is provided on the adjacent surface of the sealing end surface (19), and the limit sensor (191) is a proximity switch, a limit switch or other position detection sensor.

6. A normally closed vacuum isolation door, characterized in that: It comprises a valve plate (2) and a normally closed sealing structure as described in any one of claims 1 to 5, end face flanges are provided on both sides of the box body (1) and are respectively sealed and connected to the vacuum pipe (01), the two vacuum pipes (01) are coaxially arranged, the valve plate (2) is slidably connected to the box body (1), the plate surface of the valve plate (2) can move to or away from between the two vacuum pipes (01), the first driving mechanism is connected to the valve plate (2), the sealing door (23) is connected to the valve plate (2) through the first driving mechanism, and the spring force of the spring (27) presses the sealing door (23) against the sealing end face (19), and the sealing end face (19) is the end face of the vacuum pipe (01).

7. The normally closed vacuum isolation door according to claim 6, characterized in that: At least one first through hole (231) is provided on the sealing door (23), and the first through hole (231) is connected to two sides of the sealing door (23).

8. The normally closed vacuum isolation door according to claim 7, characterized in that: The sealing door (23) comprises a sealing ring and a sealing flange, wherein the sealing flange is connected to the end of the sealing ring, and the sealing ring and the sealing flange form a component with an L-shaped cross-section. The valve plate (2) is provided with a mounting hole for mounting the sealing door (23), and the outer ring surface of the sealing ring is slidably connected to the mounting hole. The outer ring surface of the sealing ring is provided with a mounting groove, and a radial sealing ring (232) and a guide ring (233) are provided in the mounting groove. The radial sealing ring (232) is tightly attached to the mounting hole.

9. The normally closed vacuum isolation door according to claim 8, characterized in that: The sealing ring is internally connected to a grid structure, and the first through hole (231) is arranged on the grid structure.

10. The normally closed vacuum isolation door according to claim 6, characterized in that: The top and bottom of the valve plate (2) are respectively provided with protrusions (24); a slide groove (18) is provided in the box body (1); the protrusion (24) is arranged in the slide groove (18) to form a sliding guide pair.

11. The normally closed vacuum isolation door according to claim 10, characterized in that: The convex portion of the convex block (24) has three working surfaces, each of which is provided with a group of slide plates (241), each group of slide plates (241) includes a plurality of slide plates, and the slide plates (241) are fitted in the slide groove (18).

12. The normally closed vacuum isolation door according to claim 6, characterized in that: The invention also comprises a second driving mechanism (3), which is a screw system, an oil cylinder system, an air cylinder system, a pulley system, a gear rack system or a sprocket chain system, wherein the fixed parts of the screw system, the oil cylinder system, the air cylinder system, the pulley system, the gear rack system or the sprocket chain system are connected to the housing (1), and the moving parts of the screw system, the oil cylinder system, the air cylinder system, the pulley system, the gear rack system or the sprocket chain system are connected to the valve plate (2).

13. The normally closed vacuum isolation door according to claim 12, characterized in that: The screw system comprises a screw (31) and a driver (32), wherein the driver (32) is located outside the housing (1) and is sealed and fixed on the housing (1), the screw (31) is connected to the housing (1), the driver (32) is connected to one end of the screw (31) and can drive the screw (31) to rotate, the screw (31) is threadedly connected to a screw nut, the screw nut is connected to the valve plate (2), and the screw (31) is arranged along the sliding direction of the valve plate (2).

14. The normally closed vacuum isolation door according to claim 13, characterized in that: The screw system further comprises a rotary encoder (35), wherein the rotary encoder (35) is connected inside the housing (1), and the rotary encoder (35) is connected to the other end of the screw (31).

15. The normally closed vacuum isolation door according to claim 6, characterized in that: The box body (1) comprises a front box body (11), a rear box body (12) and an end cover (13); the front box body (11) and the rear box body (12) are sealed and connected, and a box body seal (14) is provided on the joint surface; the same end of the front box body (11) and the rear box body (12) is sealed and connected to the end cover (13), and an end cover seal (15) is provided on the joint surface; the box body seal (14) and the end cover seal (15) are strip seals or plate seals.

16. The normally closed vacuum isolation door according to claim 6, characterized in that: The box body (1) is provided with three independent workstations in sequence, the workstation in the middle is a box body connecting workstation (16) connected to the vacuum pipe (01), and both sides of the box body connecting workstation (16) are respectively stay workstations for accommodating the valve plate (2). The box body connecting workstation (16) is distributed on the front and rear sides of the box body (1) and is coaxially arranged. The box body connecting workstation (16) is a circular tube with the same inner diameter as the vacuum pipe (01), and the sealing end surface (19) is arranged on the side of the box body connecting workstation (16) facing the valve plate (2).

17. The normally closed vacuum isolation door according to claim 16, characterized in that: The valve plate (2) is provided with two independent workstations in sequence, one being a valve plate sealing workstation (21) and the other being a valve plate connecting workstation (22). The valve plate connecting workstation (22) is a round tube having the same inner diameter as the box connecting workstation (16). The valve plate sealing workstation (21) is provided with the sealing door (23).

18. A two-way normally closed vacuum isolation door, characterized in that: It comprises a normally closed vacuum isolation cabin door as described in any one of claims 6 to 17, wherein the valve plate (2) is provided with two sets of normally closed sealing structures as described in any one of claims 1 to 11, and the two sealing doors (23) are respectively located on both sides of the valve plate (2), and the two sealing doors (23) are respectively used to seal the corresponding vacuum pipes (01).

19. A normally closed vacuum pipeline connection method, characterized in that: Using the normally closed vacuum isolation door according to any one of claims 6 to 17 or the bidirectional normally closed vacuum isolation door according to claim 18, the method comprises: The first driving mechanism pulls the sealing door (23) to overcome the spring force of the spring (27), and the end face sealing ring (234) is pulled away from the sealing end face (19), and the seal between the two vacuum pipes (01) on both sides of the box body (1) is released and there is no pressure difference; After the seal is released, the valve plate (2) slides in the box body (1), the valve plate (2) and the sealing door (23) are away from the two vacuum pipes (01), and the two vacuum pipes (01) are connected.

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