Oil sampling device for on-load tap changer of transformer

Abstract

The invention relates to the technical field of transformer oil sampling, in particular to a transformer on-load tap changer oil sampling device which comprises a transformer assembly which comprises a transformer body and an oil injection pipe fixedly arranged on the outer side of the transformer body, and the oil injection pipe is used for injecting oil into the transformer body; the sampling pipe is movably inserted into the oil injection pipe and is used for extracting an oil sample; and the detection assembly comprises a detection insertion disc movably inserted into the oil injection pipe, a sampling opening allowing the sampling pipe to penetrate through is formed in the middle of the detection insertion disc, and the floating detection mechanism is arranged on the outer side of the sampling pipe in a sleeving mode. The negative pressure sampling device has the beneficial effects that the sampling pipe can be directly inserted into an oil sample of the on-load tap changer stored in the inner wall of the transformer body along the inner wall of the oil injection pipe, and then the sampling pipe is connected with an external negative pressure device, so that negative pressure extraction is realized, oil does not need to be discharged firstly when the oil sample is extracted, and the sampling efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of transformer oil sampling, in particular to an oil sampling device for a transformer on-load voltage regulator. Background Art

[0002] Traditional transformers are equipped with oil sampling tubes and oil sampling valves on the main oil tank before leaving the factory. However, the main transformer on-load voltage regulating switch oil tank is isolated from the main oil tank, and the main transformer on-load voltage regulating switch oil tank capacity is generally small, so the voltage regulating switch oil tank is often only equipped with an oil drain pipe and an oil filling pipe, without reserved oil sampling tubes and oil sampling valves.

[0003] Usually when taking oil samples, the staff will release the oil drain pipe, let the oil flow out for a while, and then take the oil sample. Although this operation method may increase the possibility of taking accurate oil samples, due to the operating level of the operators and the differences in transformer structure, there is no accurate basis for how much oil flows out before the oil sample taken is the oil sample of the on-load voltage regulator, and the sampling depth cannot be adjusted, resulting in poor sampling quality. Summary of the invention

[0004] Some simplifications or omissions may be made in this section and the abstract and title of the present application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions shall not be used to limit the scope of the present invention.

[0005] The invention aims to provide an oil sampling device for an on-load voltage regulating switch of a transformer.

[0006] Therefore, its purpose is to solve the following problems: due to the differences in transformer structures, there is no accurate basis for determining how much oil is taken out after the oil flows out as the oil sample of the on-load voltage regulator, and the sampling depth cannot be adjusted.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: an oil sampling device for an on-load tap changer of a transformer, comprising a transformer assembly, comprising a transformer body, an oil filling pipe fixedly arranged on the outside of the transformer body, the oil filling pipe being used to inject oil into the interior of the transformer body, a sampling tube movably inserted into the oil filling pipe for extracting oil samples; a detection assembly, comprising a detection plug-in disk movably plugged into the oil filling pipe, a sampling port for accommodating the sampling tube being arranged in the middle of the detection plug-in disk, a floating detection mechanism sleeved on the outside of the sampling tube, the floating detection mechanism cooperating with the sampling tube for detecting the sampling depth of the sampling tube, a display mechanism being provided on the surface of the detection plug-in disk, the floating detection mechanism and the display mechanism being connected by a pneumatic hose, and being used to display the sampling depth range through the display mechanism.

[0008] As a preferred solution of the oil sampling device of the transformer on-load tap changer of the present invention, a magnetic layer is fixed at intervals on the surface of the sampling tube, an isolation film covering the magnetic layer is fixed on the surface of the sampling tube, a retaining ring is fixed on the outer side of the sampling end of the sampling tube, and the retaining ring is used to abut against the floating detection mechanism.

[0009] As a preferred solution of the oil sampling device of the transformer on-load tap changer of the present invention, the floating detection mechanism includes a floating ring body movably sleeved on the outside of the sampling tube, a magnetic pressure ring is slidably arranged inside the floating ring body, an annular elastic air bag is arranged below the magnetic pressure ring and is squeezed by the sliding of the magnetic pressure ring, and a supporting spring fixedly connected to the magnetic pressure ring is arranged inside the floating ring body.

[0010] As a preferred solution of the oil sampling device for the transformer on-load tap changer of the present invention, the air outlet end of the annular elastic airbag is connected to the pneumatic hose, the floating ring body is provided with an air inlet end connected to the annular elastic airbag, the air outlet end and the air inlet end are both installed with a first unidirectional diaphragm, and a floating block is fixed to the bottom of the floating ring body.

[0011] As a preferred solution of the oil sampling device for the transformer on-load tap changer of the present invention, the display mechanism includes an identification block, an observation window for accommodating the sliding of the identification block is opened on the detection plug-in plate, a scale display board is fixed above the observation window, and an indication part is fixed on one end of the identification block facing the scale display board.

[0012] As a preferred solution of the oil sampling device for the transformer on-load tap changer of the present invention, an elastic push layer is fixed on one side of the identification block, the elastic push layer is connected to the air outlet end of the pneumatic hose, a guide groove for constraining the expansion direction of the elastic push layer is provided inside the detection plug, and a reset spring is fixedly abutted on the side of the identification block away from the elastic push layer.

[0013] As a preferred solution of the transformer on-load tap changer oil sampling device of the present invention, the holding mechanism includes a clamping ring arranged above the scale display panel, and the detection insert is provided with a sliding groove for accommodating the parallel sliding of the clamping ring and the identification block.

[0014] As a preferred solution of the oil sampling device of the transformer on-load tap changer of the present invention, wherein: a telescopic cylinder is fixed at the bottom of the clamping ring, a trigger block is slidably connected to the bottom of the telescopic cylinder, an air vent hole for discharging gas is opened between the telescopic cylinder and the triggering block, an abutment spring is fixedly connected between the telescopic cylinder and the triggering block, and a bolt is threadedly connected to the middle part of the clamping ring for positioning the clamping ring after moving it to a preset position.

[0015] As a preferred solution of the oil sampling device of the transformer on-load tap changer of the present invention, a plurality of clamping blocks are distributed inside the sampling port for clamping the sampling tube, a scale display plate slidably connected to the clamping block is fixed inside the detection plug disk, a compression spring is fixedly connected between the scale display plate and the clamping block, a pressurizing pipe is connected to one side of the scale display plate for increasing the pressure to push the clamping block to retract, and a pressure relief pipe connected to the pressure relief port is provided on one side of the scale display plate.

[0016] As a preferred solution of the oil sampling device for the transformer on-load tap changer of the present invention, wherein: the end of the pressurized tube away from the scale display panel is connected to the air outlet end of the elastic air-filled layer, the detection plug-in disk is provided with a pressure relief tube for squeezing the elastic air-filled layer, and the air outlet and air inlet ends of the elastic air-filled layer are both installed with a second one-way diaphragm.

[0017] The beneficial effect of the transformer on-load voltage regulator oil sampling device of the present invention is that the sampling tube can be directly inserted into the oil sample of the on-load voltage regulator stored on the inner wall of the transformer body along the inner wall of the oil filling tube, and then the sampling tube is connected to the external negative pressure device to realize negative pressure extraction, so that the oil sample does not need to be drained first when being extracted, thereby improving the sampling efficiency.

[0018] Through the cooperation of the floating detection mechanism and the sampling tube, the sampling depth range of the sampling tube can be accurately detected, because oil at different depths may contain different pollutants or chemical components.

[0019] The display mechanism is connected to the floating detection mechanism through a pneumatic hose, so that the operator can read the sampling depth range directly on the surface of the detection insert without the need for additional measuring tools, thereby improving operating efficiency and accuracy.

[0020] The clamping block will hold and fix the sampling tube under the action of the abutting spring. Multiple clamping blocks will clamp more firmly. Therefore, in the subsequent oil sample extraction process, the staff does not need to hold the sampling tube for a long time, reducing labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. 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 creative work. Among them:

[0022] Figure 1 It is a schematic diagram of the overall structure of the oil sampling device for the transformer on-load tap changer in the present invention.

[0023] Figure 2 The present invention is a schematic diagram of the sampling demonstration structure of the detection component of the oil sampling device for the transformer on-load tap changer in the present invention.

[0024] Figure 3 It is a three-dimensional structural schematic diagram of the floating detection mechanism of the oil sampling device of the transformer on-load tap changer in the present invention.

[0025] Figure 4 It is a schematic diagram of the three-dimensional structure of the display mechanism of the oil sampling device for the transformer on-load tap changer in the present invention.

[0026] Figure 5 It is a schematic diagram of the exploded structure of the supporting mechanism of the oil sampling device for the on-load tap changer of the transformer in the present invention.

[0027] Figure 6 It is a partial cross-sectional structural schematic diagram of the supporting mechanism of the oil sampling device for the on-load tap changer of the transformer in the present invention.

[0028] In the figure:

[0029] 100, transformer assembly; 101, transformer body; 102, oil filling pipe; 103, sampling tube;

[0030] 103a, pneumatic hose; 103b, magnetic layer; 103c, retaining ring;

[0031] 200, detection component; 201, detection insert; 202, floating detection mechanism; 203, display mechanism; 204, supporting mechanism;

[0032] 202a, floating ring body; 202b, magnetic pressure ring; 202c, annular elastic airbag; 202d, supporting spring; 202e, gas supply port;

[0033] 203a, identification block; 203b, elastic push layer; 203c, return spring; 203d, scale display panel;

[0034] 204a, snap ring; 204b, telescopic cylinder; 204c, trigger block; 204d, clamping block; 204e, clamping cylinder; 204f, pressurizing tube; 204g, pressure relief tube; 204h, elastic inflatable layer; 204j, pressing block. DETAILED DESCRIPTION

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0036] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0037] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor does it refer to a separate or selective embodiment that is mutually exclusive with other embodiments.

[0038] Example 1

[0039] Reference Figure 1-2 , which is the first embodiment of the present invention, and provides an oil sampling device for an on-load tap changer of a transformer, comprising a transformer assembly 100, which comprises a transformer body 101, an oil filling pipe 102 fixedly arranged on the outside of the transformer body 101, the oil filling pipe 102 is used to inject oil into the transformer body 101, and a sampling pipe 103 movably inserted into the oil filling pipe 102 for extracting oil samples; a detection assembly 200, which comprises a detection plug-in disk 201 movably plugged into the oil filling pipe 102, a sampling port for accommodating the sampling pipe 103 is opened in the middle of the detection plug-in disk 201, and a floating detection mechanism 202 is sleeved on the outside of the sampling pipe 103, the floating detection mechanism 202 cooperates with the sampling pipe 103 to detect the sampling depth of the sampling pipe 103, and a display mechanism 203 is provided on the surface of the detection plug-in disk 201, and the floating detection mechanism 202 and the display mechanism 203 are connected by a pneumatic hose 103a, and are used to display the sampling depth range through the display mechanism 203.

[0040] By cooperating with the floating detection mechanism 202 and the sampling tube 103, the sampling depth range of the sampling tube 103 can be accurately detected, because oil at different depths may contain different pollutants or chemical components. The display mechanism 203 is connected to the floating detection mechanism 202 through the pneumatic hose 103a, so that the operator can read the sampling depth range directly on the surface of the detection plug disk 201 without the need for additional measuring tools, thereby improving the efficiency and accuracy of the operation. The detection plug disk 201 is movably plugged into the oil filling tube 102, which means that it can be easily disassembled when not in use, which is convenient for maintenance and cleaning.

[0041] Example 2

[0042] Reference Figure 2-4This is the second embodiment of the present invention. Different from the previous embodiment, a magnetic layer 103b is fixed at intervals on the surface of the sampling tube 103, a layer of isolation film covering the magnetic layer 103b is fixed on the surface of the sampling tube 103, and a retaining ring 103c is fixed on the outside of the sampling end of the sampling tube 103. The retaining ring 103c is used to abut against the floating detection mechanism 202. The floating detection mechanism 202 includes a floating ring body 202a movably sleeved on the outside of the sampling tube 103, a magnetic pressure ring 202b is slidably arranged inside the floating ring body 202a, an annular elastic airbag 202c that is slidably squeezed by the magnetic pressure ring 202b is arranged below the magnetic pressure ring 202b, and a supporting spring 202d fixedly connected to the magnetic pressure ring 202b is arranged inside the floating ring body 202a. The air outlet of the annular elastic airbag 202c is connected to the pneumatic hose 103a, and the floating ring body 202a is provided with an air inlet connected to the annular elastic airbag 202c. The first one-way diaphragm is installed inside the air outlet and the air inlet, and a floating block is fixed at the bottom of the floating ring body 202a.

[0043] The presence of the magnetic layer 103b enables the sampling tube 103 to interact with the magnetic pressure ring 202b, thereby achieving the positioning of the sampling tube 103. The use of the isolation film protects the magnetic layer 103b, reduces the impact of the external environment, and prolongs the service life. The setting of the floating block enables the entire floating detection mechanism 202 to remain stable in the liquid, ensuring the smooth progress of the sampling process.

[0044] The display mechanism 203 includes a marking block 203a. An observation window for accommodating the sliding of the marking block 203a is provided on the detection insert 201. A scale display plate 203d is fixed above the observation window. An indicator is fixed to one end of the marking block 203a facing the scale display plate 203d. An elastic push layer 203b is fixed to one side of the marking block 203a. The elastic push layer 203b is connected to the air outlet end of the pneumatic hose 103a. A guide groove for constraining the expansion direction of the elastic push layer 203b is provided inside the detection insert 201. A reset spring 203c is fixed to the side of the marking block 203a away from the elastic push layer 203b.

[0045] In this embodiment, when in use, the sampling tube 103 can be first inserted into the oil filling tube, so that the sampling tube 103 is directly inserted into the oil sample of the on-load tap changer stored on the inner wall of the transformer body 101 along the inner wall of the oil filling tube. Subsequently, the sampling tube 103 is connected to the external negative pressure device to realize negative pressure extraction, so that the oil sample does not need to be drained first when being extracted, thereby improving the sampling efficiency.

[0046] In addition, refer to Figure 2 When the sampling tube 103 is sampling, the floating detection mechanism 202 will be brought above the oil sample. The floating detection mechanism 202 can float directly above the oil sample through the buoyancy generated by the floating block at the bottom, thereby achieving a positioning effect.

[0047] refer to Figure 2-3 The floating ring body 202a is movably sleeved on the sampling tube 103, so when the floating ring body 202a floats above the oil sample, the sampling tube 103 can continue to slide downward, thereby extracting oil samples at different depths, thereby improving the accuracy of subsequent detection, and the magnetic layers 103b arranged at intervals on the sampling tube 103 have a magnetic adsorption effect on the magnetic pressure ring 202b, that is, when the sampling tube 103 slides downward, it drives the magnetic layer 103b to slide down, and when a certain magnetic layer 103b corresponds to the magnetic pressure ring 202b, the magnetic layer 103b will drive the magnetic pressure ring 202b to slide down, and the magnetic pressure ring 202b will compress the gas in the annular elastic airbag 202c during the sliding process. Since the magnetic pressure ring 202b can be continuously driven to slide by multiple magnetic layers 103b, the compressed gas will drive the display mechanism 203 to move, thereby marking the range of the current descending depth of the sampling tube 103, which is convenient for the staff to sample according to different depths.

[0048] It should be noted that the annular elastic airbag 202c is connected to the display mechanism 203 through the pneumatic hose 103a to realize gas transportation, and a protective groove for accommodating the pneumatic hose 103a is opened on the outside of the sampling tube 103, and the pneumatic hose 103a is fixedly connected to the protective groove part, which can reduce friction problems during use.

[0049] refer to Figure 4 When the gas enters the elastic push layer 203b through the pneumatic hose 103a, the guide groove will constrain the expansion direction of the elastic push layer 203b, thereby pushing the identification block 203a to move. When the identification block 203a moves, the depth range of the current sampling tube 103 d can be quickly known by observing the comparison scale display board 203d. The reset spring 203c applies elastic force to the identification block 203a, so that the identification block 203a is reset when not in use, which is convenient for the next use. The detection plug-in disk 201 is equipped with an exhaust valve for exhausting the gas in the elastic push layer 203b, which is convenient for its reset operation.

[0050] The first one-way diaphragm is installed at both the outlet and inlet of the annular elastic airbag 202c. The one-way diaphragm is a rubber diaphragm used to control the flow direction of the fluid. It only allows the fluid to pass from one direction and prevents the fluid from flowing from the other direction. The principle of the one-way diaphragm is to use the elastic deformation of the diaphragm to achieve the switch function. Therefore, the annular elastic airbag 202c can prevent the gas from flowing back after being compressed, which leads to the problem of inaccurate marking.

[0051] By directly inserting the sampling tube 103 into the oil sample of the on-load tap changer inside the transformer body 101 and combining it with an external negative pressure device, oil sampling without pre-draining the oil is achieved, which greatly saves the preparation time before sampling and improves work efficiency. The introduction of the floating detection mechanism 202 can extract oil samples of different depths, enhancing the reliability of subsequent test results. Through the interaction between the magnetic layer 103b and the magnetic pressure ring 202b, and the compression of the annular elastic airbag 202c, the descent depth range of the sampling tube 103 can be displayed in real time, ensuring the recording of the sampling depth and improving the scientificity and accuracy of the detection.

[0052] Example 3

[0053] Reference Figure 5-6 , which is the third embodiment of the present invention, and this embodiment further provides an oil sampling device for an on-load tap changer of a transformer. The holding mechanism 204 includes a clamping ring 204a disposed above the scale display plate 203d, and a slide groove for accommodating the clamping ring 204a and the identification block 203a to slide parallel to each other is provided on the detection plug-in disk 201. A telescopic cylinder 204b is fixed at the bottom of the clamping ring 204a, and a trigger block 204c is slidably connected to the bottom of the telescopic cylinder 204b. A vent hole for discharging gas is provided between the telescopic cylinder 204b and the trigger block 204c, and an abutment spring is fixedly connected between the telescopic cylinder 204b and the trigger block 204c. A bolt is threadedly connected to the middle of the clamping ring 204a, which is used to position the clamping ring 204a after moving it to a preset position. A plurality of clamping blocks 204d are distributed inside the sampling port for clamping the sampling tube 103. A scale display plate 203d slidably connected to the clamping block 204d is fixed inside the detection insert 201. A compression spring is fixedly connected between the scale display plate 203d and the clamping block 204d. A pressure-increasing pipe 204f is connected to one side of the scale display plate 203d for increasing pressure to push the clamping block 204d to retract. A pressure-relief pipe 204g connected to the pressure-relief port is provided on one side of the scale display plate 203d. The end of the pressure-increasing pipe 204f away from the scale display plate 203d is connected to the air outlet end of the elastic inflatable layer 204h. A pressure-relief pipe 204g for squeezing the elastic inflatable layer 204h is provided on the detection insert 201. A second one-way diaphragm is installed at both the air outlet and air inlet ends of the elastic inflatable layer 204h.

[0054] In this embodiment, the sampling depth range of the sampling tube 103 can be positioned by the holding mechanism 204, which is convenient to use.

[0055] By loosening the bolts, the retaining ring 204a can be driven to move horizontally on the detection insert 201 to locate the sampling depth. When the identification block 203a moves below the retaining ring 204a, the identification block 203a will squeeze the trigger block 204c. The contact surface between the retaining ring 204a and the identification block 203a is an inclined surface, which makes it easy to push the trigger block 204c into the telescopic cylinder 204b, so that the trigger block 204c corresponds to the pressure relief port on the telescopic cylinder 204b, and the pressure relief port is connected to the pressure relief pipe 204g, so that the gas in the scale display plate 203d is discharged, and the pressure in the upper half of the clamping block 204d is weakened, which is not enough to overcome the elastic force of the abutting spring. The clamping block 204d will fix the sampling tube 103 under the action of the abutting spring. The clamping blocks 204d are more stable. Therefore, in the subsequent oil sample extraction process, there is no need for the staff to hold the sampling tube 103 for a long time, thereby reducing labor intensity.

[0056] In addition, by pushing the pressure block 204j, the pressure block 204j will compress the gas in the elastic inflation layer 204h into the pressurized tube 204f during the sliding process, thereby increasing the pressure in the upper half of the scale display plate 203d, so that the clamping block 204d can be retracted into the scale display plate 203d, thereby releasing the lock on the sampling tube 103.

[0057] Among them, the second one-way diaphragm is installed at the air outlet and air inlet ends of the elastic inflation layer 204h. The one-way diaphragm is a rubber diaphragm used to control the flow direction of the fluid. It only allows the fluid to pass from one direction and prevents the fluid from flowing from the other direction. The principle of the one-way diaphragm is to use the elastic deformation of the diaphragm to realize the switching function.

[0058] Importantly, it should be noted that the construction and arrangement of the present application shown in a plurality of different exemplary embodiments are only exemplary. Although only a few embodiments are described in detail in this disclosure, it should be readily understood by those who refer to this disclosure that many modifications are possible (e.g., the size, scale, structure, shape and proportion of various elements, and parameter values ​​(e.g., temperature, pressure, etc.), installation arrangement, use of materials, color, directional changes, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in the application. For example, the element shown as integrally formed can be composed of multiple parts or elements, the position of the element can be inverted or otherwise changed, and the nature or number or position of the discrete element can be changed or changed. Therefore, all such modifications are intended to be included in the scope of the present invention. The order or sequence of any process or method steps can be changed or reordered according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure of performing the function described herein, and is not only structurally equivalent but also equivalent structure. Without departing from the scope of the present invention, other replacements, modifications, changes and omissions can be made in the design, operating conditions and arrangement of the exemplary embodiments. Therefore, the invention is not limited to a specific embodiment, but extends to numerous modifications still falling within the scope of the appended claims.

[0059] Additionally, in order to provide a concise description of exemplary embodiments, all features of an actual embodiment (ie, those features that are not relevant to the best mode presently contemplated for carrying out the invention or those that are not relevant to implementing the invention) may not be described.

[0060] It will be appreciated that in the development of any actual implementation, as in any engineering or design project, numerous implementation-specific decisions may be made. Such a development effort may be complex and time-consuming, but will be a routine task of design, fabrication, and production for those of ordinary skill having the benefit of this disclosure without undue experimentation.

[0061] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A transformer on-load tap changer oil sampling device, characterized in that: include, A transformer assembly (100) comprises a transformer body (101), an oil injection pipe (102) fixedly arranged outside the transformer body (101), the oil injection pipe (102) being used to inject oil into the transformer body (101), and a sampling pipe (103) movably inserted into the oil injection pipe (102) for extracting oil samples; A detection assembly (200) comprises a detection insert (201) movably plugged into an oil filling pipe (102); a sampling port for accommodating a sampling tube (103) is provided in the middle of the detection insert (201); a floating detection mechanism (202) is sleeved on the outside of the sampling tube (103); the floating detection mechanism (202) cooperates with the sampling tube (103) to detect the sampling depth of the sampling tube (103); a display mechanism (203) is provided on the surface of the detection insert (201); the floating detection mechanism (202) and the display mechanism (203) are connected via a pneumatic hose (103a) and are used to display the sampling depth range via the display mechanism (203).

2. The oil sampling device for transformer on-load tap changer according to claim 1, characterized in that: A magnetic layer (103b) is fixed at intervals on the surface of the sampling tube (103), and an isolation film covering the magnetic layer (103b) is fixed on the surface of the sampling tube (103). A retaining ring (103c) is fixed on the outside of the sampling end of the sampling tube (103), and the retaining ring (103c) is used to abut against the floating detection mechanism (202).

3. The oil sampling device for transformer on-load tap changer according to claim 2, characterized in that: The floating detection mechanism (202) comprises a floating ring body (202a) movably sleeved on the outside of the sampling tube (103), a magnetic pressure ring (202b) being slidably arranged inside the floating ring body (202a), an annular elastic air bag (202c) being slidably squeezed by the magnetic pressure ring (202b) being arranged below the magnetic pressure ring (202b), and a supporting spring (202d) being fixedly connected to the magnetic pressure ring (202b) being arranged inside the floating ring body (202a).

4. The oil sampling device for transformer on-load tap changer according to claim 3, characterized in that: The air outlet of the annular elastic airbag (202c) is connected to the pneumatic hose (103a), and the floating ring body (202a) is provided with an air inlet connected to the annular elastic airbag (202c). A first one-way diaphragm is installed inside the air outlet and the air inlet, and a floating block is fixed to the bottom of the floating ring body (202a).

5. The oil sampling device for transformer on-load tap changer according to claim 4, characterized in that: The display mechanism (203) comprises an identification block (203a); an observation window for accommodating the sliding of the identification block (203a) is provided on the detection insert (201); a scale display plate (203d) is fixedly provided above the observation window; and an indicating portion is fixedly provided at one end of the identification block (203a) facing the scale display plate (203d).

6. The oil sampling device for transformer on-load tap changer according to claim 5, characterized in that: An elastic push layer (203b) is fixed on one side of the identification block (203a), and the elastic push layer (203b) is connected to the air outlet end of the pneumatic hose (103a). A guide groove for restricting the expansion direction of the elastic push layer (203b) is provided inside the detection plug disk (201), and a return spring (203c) is fixedly abutted on the side of the identification block (203a) away from the elastic push layer (203b).

7. The oil sampling device for transformer on-load tap changer according to claim 5, characterized in that: The holding mechanism (204) comprises a snap ring (204a) arranged above the scale display plate (203d), and a slide groove for accommodating the snap ring (204a) and the identification block (203a) to slide in parallel is provided on the detection insert plate (201).

8. The oil sampling device for transformer on-load tap changer according to claim 7, characterized in that: A telescopic cylinder (204b) is fixed at the bottom of the clamping ring (204a), a trigger block (204c) is slidably connected to the bottom of the telescopic cylinder (204b), a gas discharge hole for discharging gas is provided between the telescopic cylinder (204b) and the trigger block (204c), an abutment spring is fixedly connected between the telescopic cylinder (204b) and the trigger block (204c), and a bolt is threadedly connected at the middle of the clamping ring (204a) for positioning the clamping ring (204a) after the clamping ring (204a) is moved to a preset position.

9. The oil sampling device for transformer on-load tap changer according to claim 8, characterized in that: A plurality of clamping blocks (204d) are distributed inside the sampling port for clamping the sampling tube (103); a scale display plate (203d) slidably connected to the clamping block (204d) is fixed inside the detection insert (201); a compression spring is fixedly connected between the scale display plate (203d) and the clamping block (204d); one side of the scale display plate (203d) is connected to a pressurizing pipe (204f) for increasing pressure to push the clamping block (204d) to retract; and one side of the scale display plate (203d) is provided with a pressure relief pipe (204g) connected to the pressure relief port.

10. The oil sampling device for transformer on-load tap changer according to claim 9, characterized in that: One end of the pressurizing tube (204f) away from the scale display panel (203d) is connected to the air outlet end of the elastic inflatable layer (204h), and a pressure relief tube (204g) for squeezing the elastic inflatable layer (204h) is provided on the detection plug-in disk (201), and a second one-way diaphragm is installed at both the air outlet and air inlet ends of the elastic inflatable layer (204h).

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