Automatic sealing device for small-diameter pipe

Abstract

The invention provides a small-diameter pipe automatic sealing device which comprises a power output assembly, a transmission assembly and a sliding sealing assembly, one transmission part of the transmission assembly is fixedly connected to the sliding sealing assembly, the sliding sealing assembly is provided with a lining, a threaded sliding sleeve, a sealing seat and a sealing ring, the sealing seat is arranged on the outer side of a nylon pipe in a sleeving mode, and the sealing ring is arranged on the outer side of the nylon pipe. The outer wall of the sealing seat is provided with a thread matching face used for being in threaded connection with the thread sliding sleeve, the inner wall of the left end of the sealing seat is provided with an inner sliding matching face, the sealing ring is arranged in the inner sliding matching face, and the lining is inserted into the sliding matching face. The threaded sliding sleeve is driven by the transmission assembly to rotate to push the lining to extrude the sealing ring. Automatic operation of sealing of the small-diameter pipe can be achieved, manual operation is not needed, and the radiation dose of operators is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of maintenance of reactor pressure vessels in nuclear power plants, and in particular to an automatic sealing device for small-diameter pipes. Background Art

[0002] During the chemical cleaning process of the reactor neutron flux tube, a nylon tube is inserted into the neutron flux tube and the cleaning medium is injected. During the process, the outer wall of the nylon tube at the reflux port and the neutron flux tube connection joint need to be sealed to prevent leakage of the cleaning medium.

[0003] The original sealing structure of nylon tube is as follows Figure 1 As shown, the sealing structure mainly consists of a locking nut 14 , a pressing block 15 , and an O-ring 16 .

[0004] The current operation method is that when the nylon tube needs to be sealed, the locking nut 14 is manually screwed clockwise, and the locking nut 14 pushes the pressing block 15, and the pressing block squeezes the O-ring 16 to deform it, thereby forming a seal between the outer wall of the nylon tube 1 and the connecting joint 17. Since the neutron flux tube cleaning is highly radioactive, the locking and releasing sealing operations need to be performed frequently, and the personnel will be exposed to radioactivity during the manual operation; and during the manual operation, the personnel will be subjected to uneven force because the force cannot be quantified, and there is a risk of leakage of the cleaning medium, resulting in the release of radioactive products into the working environment, causing pollution and increased environmental doses. Summary of the invention

[0005] The purpose of the present invention is to overcome the defects described in the prior art, thereby providing an automatic sealing device for small-diameter pipes, which can realize automatic operation of sealing small-diameter pipes without manual operation, reduce the radiation dose of operators, and reduce pollution and environmental dose.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A small-diameter tube automatic sealing device comprises a power output assembly, a transmission assembly and a sliding sealing assembly, wherein a transmission member of the transmission assembly is fixedly connected to the sliding sealing assembly, the sliding sealing assembly comprises a bushing, a threaded sleeve, a sealing seat and a sealing ring, the sealing seat is sleeved on the outside of a nylon tube, a threaded mating surface is provided on the outer wall of the sealing seat for threaded connection with the threaded sleeve, an inner sliding mating surface is provided on the inner wall of the left end of the sealing seat, the sealing ring is arranged in the inner sliding mating surface, the bushing is inserted into the sliding mating surface, and the threaded sleeve rotates under the drive of the transmission assembly to push the bushing to extrude the sealing ring.

[0008] As an implementable manner, a conical surface is provided at the junction of the nylon tube through-hole of the sealing seat and the inner sliding mating surface, and the sealing ring is placed on the conical surface.

[0009] As an implementable method, the left side of the outer wall of the sealing seat is the threaded mating surface, and the right side is the outer sliding mating surface. The left side of the inner wall of the threaded sleeve is provided with an inner thread of the threaded sleeve that is adapted to the threaded mating surface, and the right side of the inner wall is provided with a threaded sleeve sliding surface that is adapted to the outer sliding mating surface, so that the threaded sleeve can rotate and slide on the sealing seat.

[0010] As an practicable manner, the bushing has a shoulder, which abuts against the inner side surface of the end of the threaded sleeve. The bushing is provided with an elastic retaining ring, which abuts against the outer side surface of the end of the threaded sleeve, so that the bushing is pushed to move axially when the threaded sleeve rotates.

[0011] As an practicable manner, the power output assembly is a reduction motor, and the transmission assembly is a gear transmission assembly.

[0012] As an practicable manner, the gear transmission assembly includes a large gear, a small gear, a sleeve and a mounting seat, the reduction motor is mounted on the mounting seat, the sleeve is mounted on the output shaft of the reduction motor, the small gear is mounted on the sleeve, the small gear is meshed with the large gear, and the large gear is mounted on the threaded sleeve.

[0013] As an implementable manner, the cover shell is fixed on the mounting seat.

[0014] As an practicable manner, the power output assembly is a servo motor, a tubular motor, a pneumatic device, a hydraulic device or an electromagnetic device.

[0015] As an practicable manner, one end of the three-way joint assembly is connected to the sealing seat via threads.

[0016] Compared with the prior art, the small-diameter tube automatic sealing device provided by the present invention has the following beneficial effects:

[0017] The present invention can realize the automatic operation of sealing the small-diameter pipe without manual operation, thereby reducing the radiation dose of the operators.

[0018] The locking force of the present invention is uniform and adjustable, thus avoiding the risk of medium leakage caused by uneven fastening force due to manual operation of the locking nut.

[0019] The invention is a component of a complete set of automation equipment for neutron flux tubes and serves the entire set of automation systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention 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 invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 A schematic diagram of the original sealing structure of a nylon tube provided by the prior art;

[0022] Figure 2 This is a schematic diagram of the structure of the automatic sealing device for small-diameter pipes provided by the present invention;

[0023] Figure 3 for Figure 2 Enlarged view of point A in the middle.

[0024] Description of reference numerals:

[0025] 1- nylon tube, 2- bushing, 3- threaded sleeve, 4- sealing seat, 5- large gear, 6- three-way joint assembly, 7- elastic retaining ring, 8- sealing ring, 9- cover, 10- small gear, 11- shaft sleeve, 12- mounting seat, 13- reduction motor; 14- locking nut, 15- clamping block, 16- O-ring, 17- connecting joint. DETAILED DESCRIPTION

[0026] The following is further explained in detail through specific implementation methods.

[0027] like Figure 2 and 3 As shown, the present invention provides an automatic sealing device for small-diameter tubes. The main body of the entire device includes a power output assembly, a transmission assembly, and a sliding sealing assembly. The entire device is connected to the neutron flux tube through a three-way joint assembly 6, and the outer wall of the nylon tube 1 is sealed at the sealing ring 8.

[0028] The power output assembly preferably uses a reduction motor 13 as a power source (such as Figure 2 As shown), other motors such as servo motors, tubular motors, or pneumatic devices, hydraulic devices, electromagnetic devices, etc. can also be used to achieve sealed power output.

[0029] The small diameter tube automatic sealing device is connected to the control system through PLC. According to the cleaning function requirements, the program automatically controls the operation and stop, forward and reverse rotation of the reduction motor 13, drives the transmission component, and slides the sealing component to achieve automatic sealing and release of the nylon tube.

[0030] The transmission assembly includes a large gear 5, a small gear 10, a sleeve 11, and a mounting seat 12. The reduction motor 13 is mounted on the mounting seat 12, the sleeve 11 is mounted on the output shaft of the reduction motor 13, the small gear 10 is mounted on the sleeve 11, and the small gear 10 is meshed with the large gear 5. The large gear 5 is mounted on the threaded sleeve 3. The connection methods of the above components include locking screws, interference fit, flat key connection, spline connection, thread and sealant.

[0031] The sliding seal assembly includes a bushing 2, a threaded sleeve 3, a sealing seat 4, an elastic retaining ring 7, and a sealing ring 8. The three-way joint assembly 6 is connected to the sealing seat 4 through a thread, and the sealing seat 4 is fixed on the mounting seat 12. The outer wall of the sealing seat 4 is divided into sections with an outer sliding mating surface and a threaded mating surface ( Figure 3 The left side of the outer ring surface of the threaded sleeve 3 is a threaded mating surface, and the right side is a smooth sliding mating surface), which cooperates with the threaded sleeve 3 with the same structure for transmission, that is, the left side of the inner wall of the threaded sleeve 3 is provided with a threaded sleeve internal thread that matches the threaded mating surface, and the right side of the inner wall is provided with a threaded sleeve sliding surface that matches the outer sliding mating surface, so as to realize the movement function of the threaded sleeve 3 rotating and sliding on the sealing seat 4, that is, the meshing of large and small gears drives the threaded sleeve 3 to rotate forward and reverse along the thread direction, so as to realize the forward and backward movement of the threaded sleeve 3 on the sealing seat 4; the transmission structure has a self-locking function, that is, the whole set of sealing transmission is realized by three methods: a reduction motor, a gear, and a thread. The motor drives the gear, the gear drives the thread, and the axial movement of the threaded sleeve drives the axial movement of the bushing, thereby realizing the tightening and relaxation of the bushing on the sealing ring 8. The self-locking function means that under the drive of the reduction motor, the bushing can stay in the sealing or loosening position, and the reduction motor position is locked at this position, and the threaded sleeve cannot rotate, that is, it is locked in this position to realize self-locking.

[0032] like Figure 2 As shown, the sealing seat 4 is a hollow structure, which is sleeved on the nylon tube 1. The inner hole of the sealing seat 4 includes two sections, namely the inner sliding fitting surface located on the left side and the nylon tube perforation located on the right side, and the junction between the inner sliding fitting surface and the nylon tube perforation is a conical surface. The inner sliding fitting surface is matched with the right end of the bushing 2, and the bushing 2 is inserted into the inner sliding fitting surface to achieve relative sliding between the bushing 2 and the sealing seat 4. The threaded sleeve 3 rotates to the right to push the bushing 2 to slide to the right, and the threaded sleeve 3 can slide left and right. The nylon tube perforation in the sealing seat 4 effectively limits the excessive deformation of the nylon tube 1 in the radial direction while ensuring the smooth passage of the nylon tube 1.

[0033] The bushing 2 is axially fixed on the threaded sleeve 3 through its own shaft shoulder and elastic retaining ring 7. The bushing 2 is clamped on both sides of the threaded sleeve 3 through the shaft shoulder and elastic retaining ring 7. The sleeve 2 and the threaded sleeve 3 are axially fixed to the threaded sleeve 3 through the spring retaining ring 7 and its own shaft shoulder, but the circumferential direction is not fixed. When the threaded sleeve 3 slides on the sealing seat 4, it drives the bushing 2 to slide linearly, thereby tightening or loosening the sealing ring 8. The inner diameter of the sealing ring 8 is slightly larger than the outer diameter of the nylon tube 1. When the bushing 2 presses the sealing ring 8, the sealing ring 8 is squeezed and deformed. At this time, the sealing ring 8 is tightly fitted with the outer wall of the nylon tube 1, the conical surface of the sealing seat 4 and the end face of the bushing 2 (such as Figure 3 As shown), extrusion seals are formed at these three locations to achieve sealing of the outer wall of the nylon tube 1.

[0034] like Figure 2 As shown, the large gear 5 is fixed on the threaded sleeve 3, the small gear 10 is fixed on the output shaft of the reduction motor 13 through the shaft sleeve 11, and the reduction motor 13 is fixed on the mounting seat 12. The small gear 10 is wider than the large gear 5, ensuring that the large gear 5 always keeps meshing with the small gear 10 when driving the threaded sleeve 3 to move within the working stroke.

[0035] The cover 9 is fixed on the mounting seat 12 to protect the transmission mechanism.

[0036] The present invention adopts gear and thread transmission, and can also adopt transmission forms such as worm gear transmission, connecting rod transmission, etc.

[0037] The process of implementing sealing by the small-diameter tube automatic sealing device of the present invention is as follows:

[0038] The reduction motor 13 is powered on to operate, so that the device is in a released sealing state: the bushing 2 (threaded sleeve 3, large gear 5) is in the left limit working position, and the sealing ring 8 is not squeezed and deformed;

[0039] Insert the nylon tube 1 into the device and extend it to the bottom of the neutron flux tube;

[0040] Start the reduction motor 13 to rotate clockwise: at this time, the small gear 10 rotates clockwise, and the large gear 5 meshing with it drives the threaded sleeve 3 to rotate counterclockwise while moving to the right, that is, the large gear 5 is fixed to the threaded sleeve 3, and the rotation of the large gear 5 will drive the threaded sleeve 3 to move axially, so that the large gear 5 will also move axially; at the same time, the threaded sleeve 3 drives the bushing 2 to move synchronously to the right until the sealing ring 8 is pressed tightly against the conical surface of the sealing seat 4;

[0041] The inner diameter of the sealing ring 8 is reduced by extrusion, and the sealing ring 8 is tightly fitted with the outer wall of the capillary 1 to complete the sealing of the outer wall of the capillary.

[0042] Similarly, the counterclockwise rotation of the reduction motor 13 is the process of releasing the seal of the small-diameter tube automatic sealing device.

[0043] Therefore, the present invention realizes automatic sealing of the outer wall of the nylon tube during the chemical cleaning process of the neutron flux tube. When the seal is released by the motor, the nylon tube is in an unsealed state and can move freely in the axial direction under the action of external force; when the seal is implemented by the motor, the nylon tube is in a sealed state and is fixed in the axial direction.

[0044] The invention can seal gas, water or other fluid media.

[0045] The present invention can seal the outer walls of pipes made of other materials except nylon, such as steel pipes, aluminum pipes, copper pipes and the like.

[0046] The present invention adopts thread transmission to ensure that the original reliable sealing state can be maintained even when the external power fails.

[0047] The present invention can realize the sealing of the outer walls of pipelines with different diameters by changing the sizes of the sealing ring and the associated matching parts.

[0048] The present invention is lightweight in design and compact in structure. The structural designs of the power device, transmission assembly and sealing assembly should be protected.

[0049] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An automatic sealing device for small diameter pipes, characterized in that: The invention comprises a power output component, a transmission component and a sliding seal component, wherein a transmission member of the transmission component is fixedly connected to the sliding seal component, and the sliding seal component comprises a bushing (2), a threaded sleeve (3), a sealing seat (4) and a sealing ring (8), wherein the sealing seat (4) is sleeved on the outside of a nylon tube (1), and a threaded mating surface is provided on the outer wall of the sealing seat (4) for threaded connection with the threaded sleeve (3), and an inner sliding mating surface is provided on the inner wall of the left end of the sealing seat (4), and the sealing ring (8) is arranged in the inner sliding mating surface, and the bushing (2) is inserted into the sliding mating surface, and the threaded sleeve (3) is rotated under the drive of the transmission component to push the bushing (2) to squeeze the sealing ring (8).

2. The small diameter tube automatic sealing device according to claim 1, characterized in that: A conical surface is provided at the junction of the nylon tube through-hole of the sealing seat (4) and the inner sliding fitting surface, and the sealing ring (8) is placed on the conical surface.

3. The small diameter tube automatic sealing device according to claim 1, characterized in that: The left side of the outer wall of the sealing seat (4) is the threaded mating surface, and the right side is the outer sliding mating surface. The left side of the inner wall of the threaded sleeve (3) is provided with an inner thread of the threaded sleeve that matches the threaded mating surface, and the right side of the inner wall is provided with a threaded sleeve sliding surface that matches the outer sliding mating surface, so that the threaded sleeve (3) can rotate and slide on the sealing seat (4).

4. The small diameter tube automatic sealing device according to claim 1, characterized in that: The bushing (2) has a shaft shoulder, which abuts against the inner side surface of the end of the threaded sleeve (3). The bushing (2) is provided with an elastic retaining ring (7), which abuts against the outer side surface of the end of the threaded sleeve (3) so that the bushing (2) is pushed to move axially when the threaded sleeve (3) rotates.

5. The small diameter tube automatic sealing device according to claim 1, characterized in that: The power output assembly is a reduction motor (13), and the transmission assembly is a gear transmission assembly.

6. The small diameter tube automatic sealing device according to claim 5, characterized in that: The gear transmission assembly comprises a large gear (5), a small gear (10), a shaft sleeve (11) and a mounting seat (12); the reduction motor (13) is mounted on the mounting seat (12); the shaft sleeve (11) is mounted on the output shaft of the reduction motor (13); the small gear (10) is mounted on the shaft sleeve (11); the small gear (10) is meshed with the large gear (5); and the large gear (5) is mounted on the threaded sleeve (3).

7. The automatic sealing device for small diameter pipes according to claim 6, characterized in that: The cover shell (9) is fixed on the mounting seat (12).

8. The small diameter tube automatic sealing device according to claim 1, characterized in that: The power output assembly is a servo motor, a tubular motor, a pneumatic device, a hydraulic device or an electromagnetic device.

9. The small diameter tube automatic sealing device according to claim 1, characterized in that: One end of the three-way joint assembly (6) is connected to the sealing seat (4) via a thread.

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