CN105632707B - A Reversing Structure of Oil Inlet and Outlet of Transformer Oil Purifier - Google Patents

Abstract

The invention relates to a reversing structure of oil inlet and outlet ports of a transformer oil filter, which includes a transformer, an oil filter, an oil tank A, an oil tank B, a first solenoid valve group, a second solenoid valve group, a third solenoid valve group, The first pipeline, the second pipeline, the third pipeline, the fourth pipeline, the first oil inlet pipeline, the first oil outlet pipeline, the second oil inlet pipeline, the second oil outlet pipeline and the fifth pipeline; The first solenoid valve group is a three-position three-way double-control electromagnetic directional valve, the second solenoid valve group is a three-position four-way double-control electromagnetic directional valve, and the third solenoid valve group is a three-position four-way double-control electromagnetic directional valve. It also includes circuit devices; the invention has compact structure, clean and hygienic working environment, intelligent and convenient operation, greatly improved work efficiency, low cost, easy realization, no disassembly and assembly, and is suitable for large-scale promotion.

Description

A Reversing Structure of Oil Inlet and Outlet of Transformer Oil Purifier

technical field

The invention relates to a reversing structure of an oil inlet and an outlet of a transformer oil purifier, and relates to an auxiliary device for changing oil of a transformer.

Background technique

The transformer is the core equipment of the power system and is responsible for the power supply in a certain area. The oil filter unit is the necessary equipment for the overhaul of the transformer, which is responsible for the functions of oil withdrawal, oil return, filtration, vacuum oil injection and so on. The transformer oil filter is connected between the transformer and the oil storage tank. During the overhaul period, the oil withdrawal and oil return work should be performed at least once a day, that is, the oil inlet and outlet should be switched at least once every working day, so that the transformer oil can be removed from a storage space. to another storage space. Because the residual oil in the pipeline connected to the oil filter cannot be effectively removed, incidents of oil pollution to the working environment, dirty work clothes, and corrosion of insulating shoes often occur during the reversing process. Every time the oil inlet and outlet are switched, it is necessary to remove multiple bolts and carry a long pipeline, which is time-consuming, labor-intensive, and even affects the work progress.

Generally, only one oil tank is used for oil change, one end goes in and one end goes out. After the oil filter machine, the insulation performance of the transformer is improved. The slightly improved transformer oil is mixed with the low-quality oil in the tank, and the oil filtration efficiency is very low. .

Contents of the invention

The technical problem to be solved by the present invention is to provide a structure with reasonable structure, low cost, clean working environment and reversing structure of the oil inlet and outlet of the transformer oil filter.

In order to solve the problems referred to above, the technical scheme that the present invention takes is:

The present invention includes a transformer, an oil filter, an oil tank A, an oil tank B, a first solenoid valve group, a second solenoid valve group, a third solenoid valve group, a first pipeline, a second pipeline, and a third pipeline , the fourth pipeline, the first oil inlet pipeline, the first oil outlet pipeline, the second oil inlet pipeline, the second oil outlet pipeline and the fifth pipeline;

The transformer oil port d of the transformer communicates with the first oil inlet f of the first solenoid valve group through the first pipeline, and the first main oil outlet e1 of the first solenoid valve group communicates with the second solenoid valve group through the second pipeline The second main oil inlet o1 of the second solenoid valve group communicates with the second oil outlet p of the second solenoid valve group through the third pipeline and the third inlet c1 of the oil filter unit, and the third outlet c2 of the oil filter unit passes through the fourth pipe The road is connected with the third oil inlet u of the third electromagnetic valve group, and the third secondary oil outlet v2 of the third electromagnetic valve group is connected with the first inlet a1 of the oil tank A through the first oil outlet line, and the oil tank A’s The first outlet a2 communicates with the second auxiliary oil inlet o2 of the second solenoid valve group through the first oil inlet pipeline, and the third main oil outlet v1 of the third solenoid valve group communicates with the first solenoid valve group through the fifth pipeline The first secondary oil outlet e2 of the third solenoid valve group is connected with the third side oil outlet v3 through the second oil outlet pipeline to communicate with the second inlet b1 of the oil tank B, and the second outlet b2 of the oil tank B is connected through the second outlet b2 of the oil tank B The second oil inlet pipeline communicates with the second bypass oil inlet o3 of the second solenoid valve group.

Further, the first solenoid valve group is a three-position three-way double-control electromagnetic reversing valve, the second solenoid valve group is a three-position four-way double-control electromagnetic reversing valve, and the third solenoid valve group is a three-position four-way double-control electromagnetic reversing valve. to the valve.

Further, a circuit device is also included, and the circuit device includes a first branch, a second branch and a third branch connected in parallel at both ends of the power supply;

The first branch includes the first main switch SB11, the first linkage switch SB12, the first control coil KA1 and the second control coil KA2 located on the first solenoid valve group; the normally closed contact of the first linkage switch SB12 and the first The first main branch is formed after the control coil KA1 is connected in series, the normally open contact of the first linkage switch SB12 is connected in series with the second control coil KA2 to form the first auxiliary branch, and the first auxiliary branch is connected with the first main branch After being connected in parallel, it is connected in series with the first main switch SB11;

The second branch includes the second main switch SB21, the second linkage switch SB22, the third control coil KB1 and the fourth control coil KB2 located on the second solenoid valve group; the normally closed contact of the second linkage switch SB22 and the third The second main branch is formed after the control coil KB1 is connected in series, and the normally open contact of the second linkage switch SB22 is connected in series with the fourth control coil KB2 to form the second auxiliary branch. After parallel connection, it is connected in series with the second main switch SB21;

The third branch includes the third main switch SB31, the third linkage switch SB32, the fifth control coil KC1 and the sixth control coil KC2 located on the third solenoid valve group; the normally closed contact of the third linkage switch SB32 and the fifth The third main branch is formed after the control coil KC1 is connected in series, the normally open contact of the third linkage switch SB32 is connected in series with the sixth control coil KC2 to form the third auxiliary branch, and the third auxiliary branch is connected with the third main branch After being connected in parallel, it is connected in series with the third main switch SB31.

Further, a circuit device is also included, and the circuit device includes a first branch, a second branch and a third branch connected in parallel at both ends of the power supply;

The first branch includes the first main switch SB11, the first linkage switch SB12, the first control coil KA1 and the second control coil KA2 located on the first solenoid valve group; the normally closed contact of the first linkage switch SB12 and the first The first main branch is formed after the control coil KA1 is connected in series, the normally open contact of the first linkage switch SB12 is connected in series with the second control coil KA2 to form the first auxiliary branch, and the first auxiliary branch is connected with the first main branch After being connected in parallel, it is connected in series with the first main switch SB11;

The second branch includes the second main switch SB21, the second linkage switch SB22, the second auxiliary switch SB23, the buoyancy switch SB24, and the third control coil KB1 and the fourth control coil KB2 located on the second solenoid valve group;

The third control coil KB1 is connected in parallel with the fourth control coil KB2, the first contact m1 of the buoyancy switch SB24 is connected in parallel with the normally closed contact of the second linkage switch SB22 and then connected in series with the third control coil KB1, the first contact m1 of the buoyancy switch SB24 The second contact m2 is connected in parallel with the normally open contact of the second linkage switch SB22 and then connected in series with the fourth control coil KB2. The other end of the buoyancy switch SB24 is connected in series with the second auxiliary switch SB23 to form a second bypass branch. The second linkage switch The other end of SB22 is connected in series with the second main switch SB21 to form a first bypass branch, and the second bypass branch is connected in parallel with the first bypass branch;

The third branch includes the third main switch SB31, the third linkage switch SB32, the third auxiliary switch SB33, the buoyancy switch SB34, and the fifth control coil KC1 and the sixth control coil KC2 located on the third solenoid valve group;

The fifth control coil KC1 is connected in parallel with the sixth control coil KC2, the third contact n1 of the buoyancy switch SB34 is connected in parallel with the normally closed contact of the third linkage switch SB32 and then connected in series with the fifth control coil KC1, the third contact n1 of the buoyancy switch SB34 The four contacts n2 are connected in parallel with the normally open contacts of the third linkage switch SB32 and then connected in series with the sixth control coil KC2, the other end of the buoyancy switch SB34 is connected in series with the third auxiliary switch SB33 to form the fourth bypass branch, and the third linkage switch The other end of SB32 is connected in series with the third main switch SB31 to form a third bypass branch, and the third bypass branch is connected in parallel with the fourth bypass branch.

Further, the buoyancy switch SB24 includes a guide frame vertically arranged in the oil tank A, a guide frame is arranged in the guide frame, an upper contact and a magnet are arranged at the upper end of the guide frame, and an upper contact and a magnet are arranged at the upper end of the guide frame. The upper iron sheet corresponding to the magnet is provided with a lower contact at the lower end of the guide frame, and a lower conductive sheet corresponding to the lower contact is provided at the lower end of the guide frame; a buoyancy ball is arranged in the guide frame;

The guide frame moves vertically in the guide frame, and the buoyancy ball moves vertically in the guide frame;

The buoyancy of the guide frame + the buoyancy of the buoyancy ball > the gravity of the guide frame + the gravity of the buoyancy ball > the magnetic force of the magnet and the upper iron sheet > the gravity of the guide frame;

The buoyancy switch SB24 has the same structure as the buoyancy switch SB34.

The beneficial effects produced by adopting the above-mentioned technical scheme are:

The present invention has a compact structure. By adopting the above-mentioned hydraulic pipeline, it avoids manual repeated and alternate movement of the pipeline. The working environment is clean and hygienic, and the operation is intelligent and convenient, which greatly improves the work efficiency. The oil tank A3 and the oil tank B4 are used to reciprocate and circulate multiple times to filter, Improve the filtering effect and realize comprehensive and thorough filtering. Through the linkage switch control, the work efficiency and work quality are further improved, and it is easy to use. Of course, manual control and manual operation can also be used. Realize unmanned operation, improve the quality of oil filtration, advanced design, compact and reasonable structure, low cost, easy to implement, free of disassembly and assembly, and suitable for large-scale promotion.

Description of drawings

Fig. 1 is a structural block diagram of the present invention.

Fig. 2 is a block diagram of the electrical structure of Embodiment 1 of the present invention.

Fig. 3 is a block diagram of the electrical structure of Embodiment 2 of the present invention.

Fig. 4 is a structural schematic diagram of the buoyancy ball of the present invention.

Among them: 1. Transformer; 2. Oil filter unit; 3. Oil tank A; 4. Oil tank B; 5. The first solenoid valve group; 6. The second solenoid valve group; 7. The third solenoid valve group; 8. The first pipeline; 9, the second pipeline; 10, the third pipeline; 11, the fourth pipeline; 12, the first oil inlet pipeline; 13, the first oil outlet pipeline; 14, the second oil inlet pipeline; 15. The second oil outlet pipeline; 16. The fifth pipeline;

The first inlet a1, the first outlet a2, the second inlet b1, the second outlet b2, the third inlet c1, the third outlet c2, the transformer oil port d, the first oil inlet f, the first main oil outlet e1, The first auxiliary oil outlet e2, the second main oil inlet o1, the second auxiliary oil inlet o2, the second side oil inlet o3, the second oil outlet p, the third main oil outlet v1, the third auxiliary Oil outlet v2, third side oil outlet v3, third oil inlet u; 17, buoyancy ball; 18, guide frame; 19, upper iron sheet; 20, upper contact; 21, lower conductive sheet; 22, Lower contact; 23, guide frame; 24, first branch; 25, second branch; 26, third branch; 27, magnet.

detailed description

As shown in Figure 1, the present invention includes a transformer 1, an oil filter 2, an oil tank A3, an oil tank B4, a first solenoid valve group 5, a second solenoid valve group 6, a third solenoid valve group 7, a first pipe Road 8, second pipeline 9, third pipeline 10, fourth pipeline 11, first oil inlet pipeline 12, first oil outlet pipeline 13, second oil inlet pipeline 14, second oil outlet pipeline 15 and the first Five pipelines 16;

The transformer oil port d of the transformer 1 communicates with the first oil inlet f of the first solenoid valve group 5 through the first pipeline 8, and the first main oil outlet e1 of the first solenoid valve group 5 communicates with the first oil outlet e1 of the first solenoid valve group 5 through the second pipeline 9. The second main oil inlet o1 of the second solenoid valve group 6 is connected, and the second oil outlet p of the second solenoid valve group 6 is connected with the third inlet c1 of the oil filter unit 2 through the third pipeline 10, and the oil filter unit The third outlet c2 of 2 communicates with the third oil inlet u of the third solenoid valve group 7 through the fourth pipeline 11, and the third auxiliary oil outlet v2 of the third solenoid valve group 7 communicates with the third oil outlet v2 through the first oil outlet pipeline 13 The first inlet a1 of the oil tank A3 is connected, the first outlet a2 of the oil tank A3 is connected with the second auxiliary oil inlet o2 of the second electromagnetic valve group 6 through the first oil inlet pipeline 12, and the first auxiliary oil inlet o2 of the third electromagnetic valve group 7 is connected. The three main oil outlets v1 communicate with the first auxiliary oil outlet e2 of the first solenoid valve group 5 through the fifth pipeline 16, and the third bypass oil outlet v3 of the third solenoid valve group 7 passes through the second oil outlet pipeline 15 It communicates with the second inlet b1 of the oil tank B4 , and the second outlet b2 of the oil tank B4 communicates with the second bypass oil inlet o3 of the second solenoid valve group 6 through the second oil inlet pipeline 14 . By adopting the above-mentioned hydraulic pipelines, it is avoided to manually alternately move the pipelines, the working environment is clean and hygienic, the operation is intelligent and convenient, and the work efficiency is greatly improved. The oil tank A3 and the oil tank B4 are reciprocated and circulated for multiple times to improve the filtering effect. Achieve comprehensive and thorough filtration.

Preferably, the first electromagnetic valve group 5 is a three-position three-way double-control electromagnetic reversing valve, the second electromagnetic valve group 6 is a three-position four-way double-control electromagnetic reversing valve, and the third electromagnetic valve group 7 is a three-position four-way Double control electromagnetic reversing valve. As a technical revelation of the present invention, multiple valve groups can also be used in combination to realize the functions of the corresponding solenoid valve groups in the present invention. For example, multiple two-position three-way double-control solenoid valves and two-position two-way solenoid valves are superimposed and combined.

Embodiment 1: As shown in FIG. 2, this embodiment also includes a circuit device, and the circuit device includes a first branch 24, a second branch 25, and a third branch 26 connected in parallel at both ends of the power supply;

The first branch 24 includes the first main switch SB11, the first linkage switch SB12, and the first control coil KA1 and the second control coil KA2 located on the first electromagnetic valve group 5; the normally closed contacts of the first linkage switch SB12 and The first control coil KA1 is connected in series to form the first main branch, the normally open contact of the first linkage switch SB12 is connected in series with the second control coil KA2 to form the first auxiliary branch, the first auxiliary branch and the first main branch After being connected in parallel, it is connected in series with the first main switch SB11;

The second branch circuit 25 includes the second main switch SB21, the second linkage switch SB22 and the third control coil KB1 and the fourth control coil KB2 located on the second electromagnetic valve group 6; the normally closed contact of the second linkage switch SB22 and The second main branch is formed after the third control coil KB1 is connected in series, the normally open contact of the second linkage switch SB22 is connected in series with the fourth control coil KB2 to form the second auxiliary branch, and the second auxiliary branch and the second main branch After parallel connection, it is connected in series with the second main switch SB21;

The third branch circuit 26 includes the third main switch SB31, the third linkage switch SB32 and the fifth control coil KC1 and the sixth control coil KC2 located on the third electromagnetic valve group 7; the normally closed contact of the third linkage switch SB32 and The fifth control coil KC1 is connected in series to form the third main branch. The normally open contact of the third linkage switch SB32 is connected in series with the sixth control coil KC2 to form the third auxiliary branch. The third auxiliary branch and the third main branch After being connected in parallel, it is connected in series with the third main switch SB31.

Through the linkage switch control, the work efficiency and work quality are further improved, and it is easy to use. Of course, manual control and manual operation can also be used.

Embodiment 2: As shown in Figures 3 and 4, this embodiment also includes a circuit device, and the circuit device includes a first branch 24, a second branch 25, and a third branch 26 connected in parallel at both ends of the power supply;

The first branch 24 includes the first main switch SB11, the first linkage switch SB12, and the first control coil KA1 and the second control coil KA2 located on the first electromagnetic valve group 5; the normally closed contacts of the first linkage switch SB12 and The first control coil KA1 is connected in series to form the first main branch, the normally open contact of the first linkage switch SB12 is connected in series with the second control coil KA2 to form the first auxiliary branch, the first auxiliary branch and the first main branch After being connected in parallel, it is connected in series with the first main switch SB11;

The second branch circuit 25 includes a second main switch SB21, a second linkage switch SB22, a second auxiliary switch SB23, a buoyancy switch SB24, and the third control coil KB1 and the fourth control coil KB2 located on the second electromagnetic valve group 6;

The third control coil KB1 is connected in parallel with the fourth control coil KB2, the first contact m1 of the buoyancy switch SB24 is connected in parallel with the normally closed contact of the second linkage switch SB22 and then connected in series with the third control coil KB1, the first contact m1 of the buoyancy switch SB24 The second contact m2 is connected in parallel with the normally open contact of the second linkage switch SB22 and then connected in series with the fourth control coil KB2. The other end of the buoyancy switch SB24 is connected in series with the second auxiliary switch SB23 to form a second bypass branch. The second linkage switch The other end of SB22 is connected in series with the second main switch SB21 to form a first bypass branch, and the second bypass branch is connected in parallel with the first bypass branch;

The third branch 26 includes a third main switch SB31, a third linkage switch SB32, a third auxiliary switch SB33, a buoyancy switch SB34, and the fifth control coil KC1 and the sixth control coil KC2 located on the third electromagnetic valve group 7;

The fifth control coil KC1 is connected in parallel with the sixth control coil KC2, the third contact n1 of the buoyancy switch SB34 is connected in parallel with the normally closed contact of the third linkage switch SB32 and then connected in series with the fifth control coil KC1, the third contact n1 of the buoyancy switch SB34 The four contacts n2 are connected in parallel with the normally open contacts of the third linkage switch SB32 and then connected in series with the sixth control coil KC2, the other end of the buoyancy switch SB34 is connected in series with the third auxiliary switch SB33 to form the fourth bypass branch, and the third linkage switch The other end of SB32 is connected in series with the third main switch SB31 to form a third bypass branch, and the third bypass branch is connected in parallel with the fourth bypass branch.

As the preferred structure of the buoyancy switch, as shown in Figure 4, the buoyancy switch SB24 of the present invention comprises a guide frame 23 vertically arranged in the oil tank A3, a guide frame 18 is arranged in the guide frame 23, and at the upper end of the guide frame 23 The upper contact 20 and the magnet 27 are set, the upper iron piece 19 corresponding to the upper contact 20 and the magnet 27 is arranged at the upper end of the guide frame 18, the lower contact 22 is arranged at the lower end of the guide frame 23, and the lower end of the guide frame 18 is provided with The lower conductive sheet 21 corresponding to the lower contact 22; a buoyancy ball 17 is arranged in the guide frame 18;

The guide frame 18 moves vertically in the guide frame 23, and the buoyancy ball 17 moves vertically in the guide frame 18;

The buoyancy of the guide frame 18+the buoyancy of the buoyancy ball 17>the gravity of the guide frame 18+the gravity of the buoyancy ball 17>the magnetic force of the magnet 27 and the upper iron sheet 19>the gravity of the guide frame 18;

The buoyancy switch SB24 has the same structure as the buoyancy switch SB34, and existing buoyancy switches on the market can also be used. Thereby realize unmanned operation, improve the oil filtering quality, advanced design, compact structure, low cost, easy to realize.

To illustrate the working process of the present invention with embodiment 2:

1. Start the first switch SB11, the first control coil KA1, the third control coil KB1 and the fifth control coil KC1 are energized, and the pipeline is connected to the transformer oil port d - the first pipeline 8 - the first oil inlet f ——First solenoid valve group 5——First main oil outlet e1——Second pipeline 9——Second main oil inlet o1——Second solenoid valve group 6——Second oil outlet p— - the third pipeline 10 - the third inlet c1 - oil filter unit 2 - the third outlet c2 - the fourth pipeline 11 - the third oil inlet u - the third solenoid valve group 7 - the first The third oil outlet v2—the first oil outlet pipeline 13—the first inlet a1, so that the oil is filtered and enters the oil tank A3;

2. Start the second main switch SB21 and the third main switch SB31, turn off the first switch SB11, and the oil flows from the first outlet a2—the first oil inlet pipeline 12—the second auxiliary oil inlet o2—the second Solenoid valve group 6—the second oil outlet p—the third pipeline 10—the third inlet c1—oil filter unit 2—the third outlet c2—the fourth pipeline 11—the third Oil inlet u—the third solenoid valve group 7—the third side oil outlet v3—the second oil outlet pipeline 15—the second inlet b1, so that the oil is filtered and enters the oil tank B4;

3. In step 2, start the second linkage switch SB22 further, and the oil will flow from the second outlet b2—the second oil inlet pipeline 14—the second bypass oil inlet o3—the second solenoid valve group 6—the second Oil outlet p—the third pipeline 10—the third inlet c1—oil filter unit 2—the third outlet c2—the fourth pipeline 11—the third oil inlet u—the third Solenoid valve group 7—the third auxiliary oil outlet v2—the first oil outlet pipeline 13—the first inlet a1, so as to filter the oil and enter it into the oil tank A3;

As an optimization, it is possible to close the second auxiliary switch SB23 and the third auxiliary switch SB33, open the second main switch SB21, the third main switch SB31 and the first switch SB11, and control the opening and closing of the valve group through the buoyancy switch SB24 and the buoyancy switch SB34 , realize automatic unmanned operation, realize the above steps 2 and 3, and the specific working process is similar;

4. After multiple filtration cycles in steps 2 and 3 until the oil is completely filtered, the oil can be sent back to the transformer 1 from either of the two oil tanks; the following takes the oil tank A3 as an example, further, Reset the second interlock switch SB22, start the third interlock switch SB32, the first main switch SB11 and the first interlock switch SB12, and the oil flows from the second outlet b2-the second oil inlet pipeline 14-the second side oil inlet o3——second solenoid valve group 6——second oil outlet p——third pipeline 10———third inlet c1——oil filter unit 2——third outlet c2——fourth pipeline 11—the third oil inlet u—the third solenoid valve group 7—the third main oil outlet v1—the fifth pipeline 16—the first auxiliary oil outlet e2—inside the transformer oil port d.

The above functions can be completed by manipulating the on-off switch of the buoyancy switch.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be Modify the technical solutions described in the foregoing embodiments, or equivalently replace some of the technical features; it is obvious for those skilled in the art to combine multiple technical solutions of the present invention. However, these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims (5)

1. A reversing structure of the oil inlet and outlet of a transformer oil filter, characterized in that it includes a transformer (1), an oil filter (2), an oil tank A (3), an oil tank B (4), a first electromagnetic Valve group (5), second solenoid valve group (6), third solenoid valve group (7), first pipeline (8), second pipeline (9), third pipeline (10), fourth Pipeline (11), first oil inlet pipeline (12), first oil outlet pipeline (13), second oil inlet pipeline (14), second oil outlet pipeline (15) and fifth pipeline (16); The transformer oil port d of the transformer (1) communicates with the first oil inlet f of the first solenoid valve group (5) through the first pipeline (8), and the first main oil outlet of the first solenoid valve group (5) e1 communicates with the second main oil inlet o1 of the second solenoid valve group (6) through the second pipeline (9), and the second oil outlet p of the second solenoid valve group (6) passes through the third pipeline (10 ) communicates with the third inlet c1 of the oil filter unit (2), the third outlet c2 of the oil filter unit (2) passes through the fourth pipeline (11) and the third oil inlet u of the third electromagnetic valve group (7) connected, the third secondary oil outlet v2 of the third electromagnetic valve group (7) communicates with the first inlet a1 of the oil tank A (3) through the first oil outlet pipeline (13), and the first inlet a1 of the oil tank A (3) The outlet a2 communicates with the second auxiliary oil inlet o2 of the second solenoid valve group (6) through the first oil inlet pipeline (12), and the third main oil outlet v1 of the third solenoid valve group (7) passes through the fifth pipe The road (16) communicates with the first secondary oil outlet e2 of the first solenoid valve group (5), and the third bypass oil outlet v3 of the third solenoid valve group (7) communicates with the oil outlet through the second oil outlet pipeline (15). The second inlet b1 of the tank B (4) is connected, and the second outlet b2 of the oil tank B (4) is connected with the second bypass oil inlet o3 of the second solenoid valve group (6) through the second oil inlet pipeline (14) . 2. The reversing structure of the inlet and outlet oil ports of the transformer oil purifier according to claim 1, characterized in that: the first electromagnetic valve group (5) is a three-position three-way double-control electromagnetic reversing valve, and the second electromagnetic valve The group (6) is a three-position four-way double-control electromagnetic directional valve, and the third electromagnetic valve group (7) is a three-position four-way double-control electromagnetic directional valve. 3. The reversing structure of the oil inlet and outlet of the transformer oil purifier according to claim 2, characterized in that it also includes a circuit device, and the circuit device includes a first branch (24) connected in parallel at both ends of the power supply, a second Second branch (25) and the third branch (26); The first branch (24) includes the first main switch SB11, the first linkage switch SB12, and the first control coil KA1 and the second control coil KA2 located on the first electromagnetic valve group (5); the normal of the first linkage switch SB12 The closed contact is connected in series with the first control coil KA1 to form the first main branch, and the normally open contact of the first linkage switch SB12 is connected in series with the second control coil KA2 to form the first auxiliary branch. After being connected in parallel with the first main branch, it is connected in series with the first main switch SB11; The second branch (25) includes the second main switch SB21, the second interlock switch SB22, and the third control coil KB1 and the fourth control coil KB2 located on the second solenoid valve group (6); the second interlock switch SB22 normally The closed contact is connected in series with the third control coil KB1 to form a second main branch, and the normally open contact of the second linkage switch SB22 is connected in series with the fourth control coil KB2 to form a second auxiliary branch. After being connected in parallel with the second main branch, it is connected in series with the second main switch SB21; The third branch (26) includes the third main switch SB31, the third linkage switch SB32, the fifth control coil KC1 and the sixth control coil KC2 located on the third electromagnetic valve group (7); the third linkage switch SB32 is normally The closed contact is connected in series with the fifth control coil KC1 to form a third main branch, and the normally open contact of the third linkage switch SB32 is connected in series with the sixth control coil KC2 to form a third auxiliary branch. After being connected in parallel with the third main branch, it is connected in series with the third main switch SB31. 4. The reversing structure of the oil inlet and outlet of the transformer oil purifier according to claim 2, characterized in that it also includes a circuit device, and the circuit device includes a first branch (24) connected in parallel at both ends of the power supply, a second Second branch (25) and the third branch (26); The first branch (24) includes the first main switch SB11, the first linkage switch SB12, and the first control coil KA1 and the second control coil KA2 located on the first electromagnetic valve group (5); the normal of the first linkage switch SB12 The closed contact is connected in series with the first control coil KA1 to form the first main branch, and the normally open contact of the first linkage switch SB12 is connected in series with the second control coil KA2 to form the first auxiliary branch. After being connected in parallel with the first main branch, it is connected in series with the first main switch SB11; The second branch (25) includes the second main switch SB21, the second linkage switch SB22, the second auxiliary switch SB23, the buoyancy switch SB24, the third control coil KB1 and the fourth control coil located on the second electromagnetic valve group (6). Coil KB2; The third control coil KB1 is connected in parallel with the fourth control coil KB2, the first contact m1 of the buoyancy switch SB24 is connected in parallel with the normally closed contact of the second linkage switch SB22 and then connected in series with the third control coil KB1, the first contact m1 of the buoyancy switch SB24 The second contact m2 is connected in parallel with the normally open contact of the second linkage switch SB22 and then connected in series with the fourth control coil KB2. The other end of the buoyancy switch SB24 is connected in series with the second auxiliary switch SB23 to form a second bypass branch. The second linkage switch The other end of SB22 is connected in series with the second main switch SB21 to form a first bypass branch, and the second bypass branch is connected in parallel with the first bypass branch; The third branch (26) includes the third main switch SB31, the third linkage switch SB32, the third auxiliary switch SB33, the buoyancy switch SB34, the fifth control coil KC1 and the sixth control coil located on the third electromagnetic valve group (7). Coil KC2; The fifth control coil KC1 is connected in parallel with the sixth control coil KC2, the third contact n1 of the buoyancy switch SB34 is connected in parallel with the normally closed contact of the third linkage switch SB32 and then connected in series with the fifth control coil KC1, the third contact n1 of the buoyancy switch SB34 The four contacts n2 are connected in parallel with the normally open contacts of the third linkage switch SB32 and then connected in series with the sixth control coil KC2, the other end of the buoyancy switch SB34 is connected in series with the third auxiliary switch SB33 to form the fourth bypass branch, and the third linkage switch The other end of SB32 is connected in series with the third main switch SB31 to form a third bypass branch, and the third bypass branch is connected in parallel with the fourth bypass branch. 5. The reversing structure of the inlet and outlet oil ports of the transformer oil purifier according to claim 4, characterized in that: the buoyancy switch SB24 includes a guide frame (23) vertically arranged in the oil tank A (3). A guide frame (18) is provided in the frame (23), an upper contact (20) and a magnet (27) are set on the upper end of the guide frame (23), and an upper contact (20) is provided on the guide frame (18) upper end. And the upper iron sheet (19) corresponding to the magnet (27), the lower contact (22) is provided at the lower end of the guide frame (23), and the lower conductive contact (22) corresponding to the lower contact (22) is provided at the lower end of the guide frame (18). sheet (21); a buoyancy ball (17) is arranged in the guide frame (18); The guide frame (18) moves vertically in the guide frame (23), and the buoyancy ball (17) moves vertically in the guide frame (18); The buoyancy of the guide frame (18)+the buoyancy of the buoyancy ball (17)>the gravity of the guide frame (18)+the gravity of the buoyancy ball (17)>the magnetic force of the magnet (27) and the upper iron sheet (19)>the guide frame (18 ) gravity.