Vacuum tube evacuation automatic sealing device and using method

Abstract

The invention provides a vacuum tube evacuation automatic sealing device and a using method, and relates to the technical field of lift valves. The vacuum pipe evacuation automatic sealing device comprises a valve body, a valve cover and a valve rod, an evacuation pipe and a vacuum gauge are arranged on the valve body, a sealing plug is movably connected with the end of the valve rod located in the valve body, a first sealing cover is connected between the valve cover and the valve rod, the sliding sealing connection position of the valve rod and the valve cover is located on the inner side of the first sealing cover, and an odorizor is arranged in the first sealing cover. A plurality of protruding particles are distributed on the outer surface of the first sealing cover, an observation window is arranged on the valve body, a boss protruding outwards is arranged on the edge of the bottom end of the valve body, the portion, above the boss, of the valve body is sleeved with a pressing sleeve, the pressing sleeve is in threaded connection with an existing evacuation base on the vacuum pipe, and a second sealing cover is arranged at the bottom of the valve body and covers the pressing sleeve and the evacuation base inside. The second sealing cover is sleeved with a detection cover. After vacuumizing, automatic sealing can be achieved, and the situation that the vacuumizing operation is affected when a vacuum leakage point exists between the valve rod and the valve deck is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of lifting valves, and in particular to a method for using a vacuum tube evacuation automatic sealing device. Background Art

[0002] Pipes with vacuum interlayers are usually called vacuum insulated pipes or vacuum tubes. This type of pipe uses high vacuum multi-layer winding insulation technology. Its structure is generally composed of an inner pipe, an outer pipe and an interlayer. The inner and outer pipes are usually made of austenitic stainless steel pipes (such as 304 stainless steel materials), and the interlayer is formed by evacuating and possibly filling with insulation materials to form an insulation layer to reduce convective heat transfer and achieve a cold preservation effect. Due to its high vacuum insulation characteristics and low evaporation rate, vacuum tubes are widely used in the transportation of cryogenic liquids, such as liquid oxygen, liquid nitrogen, liquid argon and LNG (liquefied natural gas).

[0003] At present, a vacuum tube is generally provided with a vacuum seat, through which the interlayer of the vacuum tube is evacuated. After the interlayer is evacuated, the sealing method adopted is manual sealing, and automatic sealing cannot be achieved. In addition, there may be a vacuum leakage point between the valve stem and the valve cover in the vacuumed valve body, which affects the vacuum operation and is difficult to be discovered. Summary of the invention

[0004] The purpose of the present invention is to develop a vacuum tube automatic sealing device and a method for using the device which can realize automatic sealing after vacuuming to avoid vacuum leakage between the valve stem and the valve cover affecting the vacuuming operation.

[0005] The present invention is achieved through the following technical solutions: A vacuum tube evacuation automatic sealing device, comprising: Valve body; A valve cover, arranged on the valve body; A valve stem is slidably disposed in the valve body and is slidably and sealingly connected to the valve cover; A driving mechanism is arranged outside the valve body and is drivingly connected to the valve stem to push the valve stem to slide; The evacuation tube and vacuum gauge are installed on the valve body; A sealing plug movably connected to the end of the valve stem in the valve body; A first sealing cover made of elastic material is connected between the valve cover and the valve stem, a sliding sealing connection between the valve stem and the valve cover is located inside the first sealing cover, an odorizer is arranged inside the first sealing cover, a plurality of convex particles are covered on the outer surface of the first sealing cover, an observation window for observing the first sealing cover is arranged on the valve body, and a transparent glass is sealed inside the observation window; The bottom edge of the valve body is provided with a boss protruding outward, and a compression sleeve is sleeved on the valve body above the boss, and the compression sleeve is threadedly connected with the existing evacuation seat on the vacuum tube, and the sealing plug cooperates with the evacuation channel of the evacuation seat; A second sealing cover made of elastic material is provided at the bottom of the valve body. The second sealing cover is spherical in shape in a natural state. The top of the second sealing cover is connected to the valve body above the clamping sleeve. The second sealing cover covers the clamping sleeve and the evacuation seat inside. The bottom of the second sealing cover is fixedly sealed and connected to the evacuation seat through a clamp. A detection cover made of elastic material is sleeved on the outside of the second sealing cover. The top of the detection cover is connected to the valve body. A scale for marking the position of the bottom of the detection cover is provided on the outer wall of the second sealing cover.

[0006] Optionally, a circular connecting ring is coaxially provided on the valve stem, the first sealing cover is tubular, the first sealing cover is sleeved on the outside of the valve stem, the top end of the first sealing cover is sealedly connected to the bottom surface of the valve cover on the outside of the valve stem, and the bottom end of the first sealing cover is sealedly connected to the top surface of the connecting ring on the outside of the valve stem.

[0007] Optionally, a telescopic cylinder is sleeved on the outer side of the first sealing cover, and the telescopic cylinder is coaxially arranged with the valve stem. The telescopic cylinder includes an upper cylinder and a lower cylinder coaxially slidably connected, and the lower cylinder slides on the inner wall of the upper cylinder, the top end of the upper cylinder is connected to the valve cover on the outer side of the top end of the first sealing cover, and the bottom end of the lower cylinder is connected to the connecting ring on the outer side of the bottom end of the first sealing cover.

[0008] Optionally, the observation window is located on the side of the upper cylinder, an observation port is provided on the upper cylinder inside the observation window, an observation groove opened along the axis parallel to the top of the lower cylinder is provided, the observation port is on the sliding track of the observation groove, and transparent glass is provided in the observation groove and the observation port.

[0009] Optionally, a barrel mouth is provided at the bottom of the second sealing cover, the barrel mouth is connected to the evacuation seat, a ring groove cooperating with the clamp is provided on the outer wall of the barrel mouth, a circle of elastic ring is provided on the opening edge of the bottom of the detection cover, and a layer of polytetrafluoroethylene coating is provided on the outer wall of the second sealing cover and the inner wall of the detection cover.

[0010] Optionally, the scale is a ring line that is arranged in multiple circles around the axis of the second sealing cover, and the number of the ring line is located at the lower side of the ring line.

[0011] Optionally, the outer wall at the top end of the sealing plug is provided with a circle of outwardly protruding flange, and two sealing grooves are provided on the circumferential outer wall of the sealing plug, and a first sealing ring is provided in the sealing groove.

[0012] Optionally, a circular ring-shaped support plate is coaxially provided on the circumferential outer wall of the inner end of the valve stem, a rod-shaped plug is coaxially connected to the inner end of the valve stem, and a plug groove cooperating with the plug is coaxially provided on the top of the sealing plug.

[0013] Optionally, the outer wall of the evacuation seat includes a first outer wall, a second outer wall, and a third outer wall in sequence in the direction away from the vacuum tube, the first outer wall, and the third outer wall are all cylindrical, and the outer diameters of the second outer wall, the first outer wall, and the third outer wall are successively reduced, the clamping sleeve is threadedly connected to the second outer wall, the bottom of the second sealing cover is connected to the first outer wall, and a second sealing ring is provided between the boss at the bottom end of the valve body and the top end face of the second outer wall.

[0014] A method for using a vacuum tube evacuation automatic sealing device comprises the following steps: S1. Connect the sealing plug to the inner end of the valve stem, and connect the compression sleeve to the evacuation seat; S2. Pull the bottom of the second sealing cover to the evacuated seat, so that the second sealing cover remains in a natural state, and the bottom of the second sealing cover is fixedly sealed and connected to the evacuated seat by a hoop; S3. Pull the bottom opening of the detection cover down to the lower outer side of the second sealing cover, so that the detection cover is tightened on the second sealing cover by elastic force, and record the current position of the scale at the bottom opening of the detection cover; S4. The pipeline is evacuated through the evacuation tube, and the vacuum gauge measures the vacuum degree; S5. After the vacuum is completed, the valve stem is driven down to push the sealing plug into the vacuum seat for sealing; When the operator smells the odor of the odor agent in the first sealing cover, the sliding seal between the valve stem and the valve cover fails and needs to be repaired; In the steps S4 and S5, the color of the first sealing cover is checked through the observation window: If the observed color of the first sealing cover is a mixture of the first sealing cover's own color and the color of the convex particles, the first sealing cover is normal, and the internal space of the first sealing cover is sealed with the valve cavity; If the color of the first sealing cover is completely the same as the color of the convex particles, the first sealing cover is abnormal, and the internal space of the first sealing cover is connected to the valve cavity; In step S4 and step S5, observe whether the scale of the bottom opening of the detection cover on the second sealing cover changes: If there is no change, the air tightness between the valve body and the evacuation seat is good; If there is a change, keep the valve body evacuated for a while, and continue to observe the condition of the second sealing cover and whether the bottom opening of the detection cover moves further on the scale: If the bottom opening of the detection cover does not change further on the scale and the second sealing cover does not collapse, the air tightness between the valve body and the evacuation seat is good; If the second sealing cover collapses further or the bottom opening of the detection cover moves further on the scale, there is a problem with the airtightness between the valve body and the evacuation seat, and maintenance is required.

[0015] The beneficial effects of the present invention are: After the pipeline is vacuumed, it can be sealed automatically. According to the vacuum degree measured by the vacuum gauge, the valve stem is pushed by the driving mechanism to insert the sealing plug into the vacuum pump. The first sealing cover can keep the inside of the valve body sealed when the sliding seal between the valve stem and the valve cover fails, thus avoiding affecting the evacuation operation of the vacuum tube; When the sliding seal between the valve stem and the valve cover fails, the odorant set in the first sealing cover will emit an odor that can be smelled by personnel to determine the abnormal situation, so that the operating personnel can find the sealing failure in time and carry out maintenance work in time; By observing the color of the first sealing cover, it can be judged whether the first sealing cover is damaged or whether the sealing connection between the first sealing cover and the valve cover and the valve stem is invalid, so that personnel can carry out maintenance work in time; When the sliding seal between the valve stem and the valve cover fails, the expansion of the first sealing cover is limited in the telescopic cylinder, so that the telescopic cylinder protects the first sealing cover to prevent it from being damaged due to excessive expansion; When the valve body is connected to the evacuation seat for vacuuming, the second sealing cover is sealed and connected to the evacuation seat, so that the internal cavity of the second sealing cover is sealed. With the cooperation of the detection cover, it can be determined whether the connection between the valve body and the evacuation seat is sealed. If the seal fails, the second sealing cover will collapse and shrink, thereby causing the detection cover to shrink, and the scale position of the bottom of the detection cover on the second sealing cover will change, so that the operating personnel can timely discover the sealing failure. The cooperation of the second sealing cover and the detection cover can realize the detection of the sealing of the connection between the valve body and the evacuation seat, and the operating personnel can discover the sealing failure in time. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic diagram of the structure of the vacuum tube evacuation automatic sealing device; Figure 2 for Figure 1 Schematic diagram of the internal structure of the middle valve body; Figure 3 for Figure 1 Schematic diagram of the bottom structure of the middle valve body.

[0018] Figure numerals: 1. valve body; 101. observation window; 102. boss; 2. valve cover; 3. evacuation tube; 4. vacuum gauge; 5. valve stem; 501. connecting ring; 502. support plate; 503. plug; 6. sealing plug; 7. evacuation seat; 701. first outer wall; 702. second outer wall; 703. third outer wall; 8. clamping sleeve; 9. first sealing cover; 10. second sealing cover; 11. detection cover; 12. telescopic cylinder; 121. upper cylinder; 122. lower cylinder; 123. observation port; 124. observation groove; 13. clamp; 14. first sealing ring; 15. second sealing ring. DETAILED DESCRIPTION

[0019] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0023] like Figure 1~Figure 3 As shown, the present invention discloses a vacuum tube evacuation automatic sealing device, comprising a valve body 1, the valve body 1 is open at the bottom and a valve cover 2 is provided on the top, a valve stem 5 is slidably provided on the valve cover 2, the valve stem 5 is slidably and sealedly connected to the valve cover 2, the inner end of the valve stem 5 is located in the valve cavity in the valve body 1, the outer end of the valve stem 5 is located outside the valve cavity and is connected to a handle, and a driving mechanism is also provided on the side of the valve body 1 that is transmission-connected to the outer end of the valve stem 5, and the driving mechanism drives the valve stem 5 to slide.

[0024] The side of the valve body 1 is connected to an evacuation pipe 3, and the valve body 1 is provided with a vacuum gauge 4 for measuring the vacuum degree in the valve cavity.

[0025] The outer wall of the valve body 1 at the lower part of the evacuation tube 3 is cylindrical, and a boss 102 protruding radially outward is provided at the bottom edge of the valve body 1. The boss 102 is annular and coaxially connected to the valve body 1. The outer diameter of the boss 102 is larger than the outer diameter of the valve body 1, and a circle of annular convex rings protruding axially downward is coaxially provided at the bottom edge of the boss 102.

[0026] A clamping sleeve 8 is sleeved on the outer wall of the valve body 1 at the lower part of the evacuation tube 3. The clamping sleeve 8 is cylindrical, and the inner diameter of the clamping sleeve 8 is larger than the outer diameter of the boss 102. The inner edge of the top end of the clamping sleeve 8 is coaxially connected to a circular ring whose inner diameter matches the outer diameter of the valve body 1.

[0027] A circular ring-shaped support plate 502 is coaxially provided on the circumferential outer wall of the inner end of the valve stem 5 , and a rod-shaped plug 503 is coaxially connected to the inner end of the valve stem 5 .

[0028] The vacuum tube is connected with an evacuation seat 7, which is cylindrical, and its inner side is a cylindrical evacuation channel, and the evacuation seat 7 is fixed on the vacuum tube along the radial direction of the vacuum tube. The outer wall of the evacuation seat 7 includes a first outer wall 701, a second outer wall 702, and a third outer wall 703 in the direction away from the vacuum tube. The first outer wall 701, the second outer wall 702, and the third outer wall 703 are all cylindrical, and the outer diameters of the second outer wall 702, the first outer wall 701, and the third outer wall 703 are reduced in sequence.

[0029] The evacuation seat 7 is provided with a sealing plug 6 which matches with it. The sealing plug 6 is filled into the evacuation channel of the evacuation seat 7 to seal the evacuation seat 7. The outer diameter of the sealing plug 6 matches the inner diameter of the evacuation channel, and the outer wall of the top of the sealing plug 6 is provided with a circle of outwardly protruding flanges. Two sealing grooves are provided on the outer wall of the circumference of the sealing plug 6, and the first sealing ring 14 is provided in the sealing groove. The top of the sealing plug 6 is coaxially provided with a plug groove which matches with the plug head 503.

[0030] The outer diameter of the second outer wall 702 of the evacuation seat 7 is adapted to the inner diameter of the compression sleeve 8, and the second outer wall 702 and the inner wall of the compression sleeve 8 are respectively provided with matching external threads and internal threads. A second sealing ring 15 is provided between the boss 102 at the bottom end of the valve body 1 and the top end face of the second outer wall 702, and the second sealing ring 15 is located on the inner side of the convex ring at the edge of the boss 102.

[0031] A connecting ring 501 is provided on the valve stem 5 on the side of the support plate 502 close to the valve cover 2. The connecting ring 501 is annular and coaxially connected to the valve stem 5. A first sealing cover 9 is provided between the connecting ring 501 and the valve cover 2. The first sealing cover 9 is tubular and sleeved on the outside of the valve stem 5. The top end of the first sealing cover 9 is sealed and connected to the bottom surface of the valve cover 2 outside the valve stem 5. The bottom end of the first sealing cover 9 is sealed and connected to the top surface of the connecting ring 501 outside the valve stem 5. The internal cavity of the first sealing cover 9 is sealed.

[0032] The first sealing cover 9 is made of elastic material. When the valve stem 5 rises and falls in the valve cavity, the first sealing cover 9 undergoes adaptive elastic deformation. During the elastic deformation of the first sealing cover 9, the minimum air pressure inside is not less than the external air pressure. An odorant is placed in the internal cavity of the first sealing cover 9. If the sliding seal between the valve stem 5 and the valve cover 2 fails, the operator can smell a strange smell. The odorant can be tetrahydrothiophene added to natural gas.

[0033] A telescopic cylinder 12 is sleeved on the outside of the first sealing cover 9, and the telescopic cylinder 12 is coaxially arranged with the valve stem 5. The telescopic cylinder 12 includes an upper cylinder 121 and a lower cylinder 122 that are coaxially slidably connected. The outer diameter of the lower cylinder 122 is adapted to the inner diameter of the upper cylinder 121, and the lower cylinder 122 slides on the inner wall of the upper cylinder 121. The top end of the upper cylinder 121 is connected to the valve cover 2 on the outside of the top end of the first sealing cover 9, and the bottom end of the lower cylinder 122 is connected to the connecting ring 501 on the outside of the bottom end of the first sealing cover 9.

[0034] An observation window 101 is provided on the valve body 1 at the lower part of the valve cover 2. The observation window 101 is located on the side of the upper cylinder 121. Transparent glass is sealed in the observation window 101. The inside of the valve cavity can be seen through the observation window 101. An observation port 123 is provided on the upper cylinder 121 inside the observation window 101. Transparent glass is sealed in the observation port 123. An observation groove 124 is provided at the top of the lower cylinder 122 parallel to the axial direction. Transparent glass is provided in the observation groove 124. The observation port 123 is located on the sliding track of the observation groove 124. Through the cooperation of the observation window 101, the observation port 123 and the observation groove 124, the operator can see the situation of the internal first sealing cover 9 in any telescopic state of the valve stem 5.

[0035] The outer surface of the first sealing cover 9 is covered with a plurality of convex particles, and the color of these convex particles is different from the color of the first sealing cover 9. When the first sealing cover 9 is contracted, the plurality of convex particles are in close contact with each other to form a shell covering the first sealing cover 9. At this time, the color of the first sealing cover 9 observed by the naked eye is the color of the convex particles. When the first sealing cover 9 is expanded, there is a certain distance between the plurality of convex particles, and at this time, the color of the first sealing cover 9 itself can be seen by the naked eye.

[0036] A second sealing cover 10 is provided at the bottom of the valve body 1. The second sealing cover 10 is made of elastic material. In a natural state (without external force), the second sealing cover 10 is in the shape of a spherical table. The second sealing cover 10 is open at the top and has a barrel mouth at the bottom. The edge of the top opening of the second sealing cover 10 is connected to the outer wall of the valve body 1 between the evacuation tube 3 and the clamping sleeve 8, and the connection is not on the movement trajectory of the clamping sleeve 8. The barrel mouth at the bottom of the second sealing cover 10 is cylindrical and the inner diameter in the natural state is smaller than the outer diameter of the first outer wall 701 of the evacuation seat 7.

[0037] An annular groove is provided on the outer wall of the bottom barrel mouth of the second sealing cover 10, and a clamp 13 can be arranged in the annular groove. The barrel mouth is sleeved on the first outer wall 701 of the evacuation seat 7, and then the clamp 13 is installed in the annular groove and tightened to make the barrel mouth in close contact with the first outer wall 701.

[0038] The second sealing cover 10 is provided with a detection cover 11 on the outside. The detection cover 11 is also in the shape of a spherical table and its ball diameter in the natural state is smaller than the second sealing cover 10. The top opening of the detection cover 11 corresponds to the outer wall of the valve body 1 above the top opening of the second sealing cover 10. The bottom opening of the detection cover 11 is on the outer wall of the second sealing cover 10 above the tube mouth. The edge of the bottom opening of the detection cover 11 is provided with a circle of elastic ring with strong elasticity. The outer wall of the second sealing cover 10 and the inner wall of the detection cover 11 are both provided with a layer of polytetrafluoroethylene coating, so that the friction coefficient between the second sealing cover 10 and the detection cover 11 is low. The outer wall of the second sealing cover 10 is provided with a scale, which is a ring line arranged in multiple circles around the axis of the second sealing cover 10, and the number of the ring line is located on the lower side of the ring line.

[0039] After the mouth of the second sealing cover 10 is fixed on the first outer wall 701 of the evacuation seat 7, the interior of the second sealing cover 10 is sealed, and the detection cover 11 is pulled down and sleeved on the second sealing cover 10. Since the ball diameter of the detection cover 11 in its natural state is smaller than that of the second sealing cover 10, and an elastic ring with strong elasticity is provided at the edge of the bottom opening of the detection cover 11, the bottom opening of the detection cover 11 is pulled to the lower side of the second sealing cover 10, and the detection cover 11 will be tightened on the second sealing cover 10. During the vacuum pumping process, if a leak is found in the inner structure of the second sealing cover 10, that is, the seal between the valve body 1 and the evacuation seat 7 fails, the air flow in the second sealing cover 10 will enter the valve body 1, the air pressure in the second sealing cover 10 will drop, the second sealing cover 10 will collapse and shrink, the top opening of the detection cover 11 is fixed, the detection cover 11 will shrink upward, the bottom opening of the detection cover 11 will slide up, and the scale of the second sealing cover 10 where the bottom opening of the detection cover 11 is located will change, thereby judging that the seal between the valve body 1 and the evacuation seat 7 fails.

[0040] The method for using the above-mentioned vacuum tube evacuation automatic sealing device comprises the following steps: S1. Connect the sealing plug 6 to the inner end of the valve stem 5, and connect the compression sleeve 8 to the evacuation seat 7; S2. The mouth of the second sealing cover 10 is pulled to the first outer wall 701 of the evacuated seat 7, so that the second sealing cover 10 remains in a natural state, and the mouth of the second sealing cover 10 is fixedly sealed and connected to the first outer wall 701 of the evacuated seat 7 by the hoop 13; S3. Pull the bottom opening of the detection cover 11 down to the lower outer side of the second sealing cover 10, so that the detection cover 11 is tightened on the second sealing cover 10 by elastic force, and record the current detection cover 11 at the bottom opening of the scale position; S4. The pipeline is evacuated through the evacuation tube 3, and the vacuum meter 4 measures the vacuum degree; S5. After the vacuum is completed, the valve stem 5 is driven downward to push the sealing plug 6 into the vacuum seat 7 for sealing; When the operator smells the odor of the odorizing agent in the first sealing cover 9, the sliding seal between the valve stem 5 and the valve cover 2 fails and needs to be repaired; In steps S4 and S5, the color of the first sealing cover 9 is checked through the observation window 101, the observation port 123, and the observation slot 124: If the observed color of the first sealing cover 9 is a mixture of the first sealing cover 9's own color and the color of the convex particles, the first sealing cover 9 is normal, and the internal space of the first sealing cover 9 is sealed with the valve cavity; If the color of the first sealing cover 9 is completely the color of the convex particles, the first sealing cover 9 is abnormal, and the internal space of the first sealing cover 9 is connected to the valve cavity; In step S4 and step S5, observe whether the scale of the bottom opening of the detection cover 11 on the second sealing cover 10 changes: If there is no change, the air tightness between the valve body 1 and the evacuation seat 7 is good; If there is a change, the valve body 1 is kept evacuated for a period of time, and the condition of the second sealing cover 10 and the bottom opening of the detection cover 11 are continuously observed to see whether they move further on the scale: If the bottom opening of the detection cover 11 does not change further on the scale and the second sealing cover 10 does not collapse, the airtightness of the valve body 1 and the evacuation seat 7 is good; If the second sealing cover 10 collapses further or the bottom opening of the detection cover 11 moves further on the scale, there is a problem with the airtightness between the valve body 1 and the evacuation seat 7, and maintenance is required.

[0041] The above embodiments are only preferred embodiments of the present invention and are not limitations of the technical solutions of the present invention. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present invention.

Claims

1. A vacuum tube evacuation automatic sealing device, characterized in that: include: Valve body; A valve cover, arranged on the valve body; A valve stem is slidably disposed in the valve body and is slidably and sealingly connected to the valve cover; A driving mechanism is arranged outside the valve body and is drivingly connected to the valve stem to push the valve stem to slide; The evacuation tube and vacuum gauge are installed on the valve body; A sealing plug movably connected to the end of the valve stem in the valve body; A first sealing cover made of elastic material is connected between the valve cover and the valve stem, a sliding sealing connection between the valve stem and the valve cover is located inside the first sealing cover, an odorizer is arranged inside the first sealing cover, a plurality of convex particles are covered on the outer surface of the first sealing cover, an observation window for observing the first sealing cover is arranged on the valve body, and a transparent glass is sealed inside the observation window; The bottom edge of the valve body is provided with a boss protruding outward, and a compression sleeve is sleeved on the valve body above the boss, and the compression sleeve is threadedly connected with the existing evacuation seat on the vacuum tube, and the sealing plug cooperates with the evacuation channel of the evacuation seat; A second sealing cover made of elastic material is provided at the bottom of the valve body. The second sealing cover is spherical in shape in a natural state. The top of the second sealing cover is connected to the valve body above the clamping sleeve. The second sealing cover covers the clamping sleeve and the evacuation seat inside. The bottom of the second sealing cover is fixedly sealed and connected to the evacuation seat through a clamp. A detection cover made of elastic material is sleeved on the outside of the second sealing cover. The top of the detection cover is connected to the valve body. A scale for marking the position of the bottom of the detection cover is provided on the outer wall of the second sealing cover.

2. The vacuum tube automatic sealing device according to claim 1, characterized in that: A circular connecting ring is coaxially provided on the valve stem, the first sealing cover is tubular, the first sealing cover is sleeved on the outside of the valve stem, the top end of the first sealing cover is sealedly connected to the bottom surface of the valve cover outside the valve stem, and the bottom end of the first sealing cover is sealedly connected to the top surface of the connecting ring outside the valve stem.

3. The vacuum tube automatic sealing device according to claim 2, characterized in that: A telescopic cylinder is sleeved on the outer side of the first sealing cover, and the telescopic cylinder is coaxially arranged with the valve stem. The telescopic cylinder includes an upper cylinder body and a lower cylinder body that are coaxially slidably connected. The lower cylinder body slides on the inner wall of the upper cylinder body, and the top end of the upper cylinder body is connected to the valve cover on the outer side of the top end of the first sealing cover, and the bottom end of the lower cylinder body is connected to the connecting ring on the outer side of the bottom end of the first sealing cover.

4. The vacuum tube automatic sealing device according to claim 3, characterized in that: The observation window is located on the side of the upper cylinder, an observation port is provided on the upper cylinder inside the observation window, an observation groove opened parallel to the axial direction is provided on the top of the lower cylinder, the observation port is located on the sliding track of the observation groove, and transparent glass is provided in the observation groove and the observation port.

5. The vacuum tube automatic sealing device according to claim 1, characterized in that: A barrel mouth is provided at the bottom of the second sealing cover, and the barrel mouth is connected to the evacuation seat. A ring groove cooperating with the clamp is provided on the outer wall of the barrel mouth. A circle of elastic ring is provided at the opening edge of the bottom of the detection cover. The outer wall of the second sealing cover and the inner wall of the detection cover are both provided with a layer of polytetrafluoroethylene coating.

6. The vacuum tube automatic sealing device according to claim 1, characterized in that: The scale is a ring line that is arranged in multiple circles around the axis of the second sealing cover, and the number of the ring line is located at the lower side of the ring line.

7. The vacuum tube automatic sealing device according to claim 1, characterized in that: The outer wall at the top end of the sealing plug is provided with a circle of outwardly protruding flanges, and the outer wall of the sealing plug is provided with two sealing grooves, and a first sealing ring is provided in the sealing groove.

8. The vacuum tube automatic sealing device according to claim 1, characterized in that: A circular ring-shaped support plate is coaxially arranged on the circumferential outer wall of the inner end of the valve stem, a rod-shaped plug is coaxially connected to the inner end of the valve stem, and a plug groove cooperating with the plug is coaxially arranged on the top of the sealing plug.

9. The vacuum tube automatic sealing device according to claim 1, characterized in that: The outer wall of the evacuation seat includes a first outer wall, a second outer wall, and a third outer wall in sequence in the direction away from the vacuum tube. The first outer wall, the second outer wall, and the third outer wall are all cylindrical, and the outer diameters of the second outer wall, the first outer wall, and the third outer wall are reduced in sequence. The clamping sleeve is threadedly connected to the second outer wall, the bottom of the second sealing cover is connected to the first outer wall, and a second sealing ring is provided between the boss at the bottom end of the valve body and the top end face of the second outer wall.

10. A method for using the vacuum tube automatic sealing device according to any one of claims 1 to 9, characterized in that: The steps include: S1. Connect the sealing plug to the inner end of the valve stem, and connect the compression sleeve to the evacuation seat; S2. Pull the bottom of the second sealing cover to the evacuated seat, so that the second sealing cover remains in a natural state, and the bottom of the second sealing cover is fixedly sealed and connected to the evacuated seat by a hoop; S3. Pull the bottom opening of the detection cover down to the lower outer side of the second sealing cover, so that the detection cover is tightened on the second sealing cover by elastic force, and record the current position of the scale at the bottom opening of the detection cover; S4. The pipeline is evacuated through the evacuation tube, and the vacuum gauge measures the vacuum degree; S5. After the vacuum is completed, the valve stem is driven down to push the sealing plug into the vacuum seat for sealing; When the operator smells the odor of the odor agent in the first sealing cover, the sliding seal between the valve stem and the valve cover fails and needs to be repaired; In the steps S4 and S5, the color of the first sealing cover is checked through the observation window: If the observed color of the first sealing cover is a mixture of the first sealing cover's own color and the color of the convex particles, the first sealing cover is normal, and the internal space of the first sealing cover is sealed with the valve cavity; If the color of the first sealing cover is completely the same as the color of the convex particles, the first sealing cover is abnormal, and the internal space of the first sealing cover is connected to the valve cavity; In step S4 and step S5, observe whether the scale of the bottom opening of the detection cover on the second sealing cover changes: If there is no change, the air tightness between the valve body and the evacuation seat is good; If there is a change, keep the valve body evacuated for a while, and continue to observe the condition of the second sealing cover and whether the bottom opening of the detection cover moves further on the scale: If the bottom opening of the detection cover does not change further on the scale and the second sealing cover does not collapse, the air tightness between the valve body and the evacuation seat is good; If the second sealing cover collapses further or the bottom opening of the detection cover moves further on the scale, there is a problem with the airtightness between the valve body and the evacuation seat, and maintenance is required.

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