An oil gun for refilling oil in a transformer bushing

Abstract

The present invention provides an oil gun for refilling oil in a transformer bushing, which includes an oil gun body and an oil injector; the oil gun body includes an oil gun handle and an oil gun head that extends by bending from the top of the oil gun handle. An oil delivery channel is provided inside the oil gun handle and the oil gun head. One end of the oil delivery channel extends to the bottom end of the oil gun handle for connecting to an oil supply pipeline, and the other end extends to the extended end of the oil gun head; the oil injector is sealingly and rotatably connected to the extended end of the oil gun head. A plurality of oil injection nozzles are spaced apart on the peripheral wall of the oil injector, and the diameters of the respective oil injection nozzles are different and are respectively used to be inserted into the oil injection holes of different types of transformer bushings in a matching manner. Among them, when the oil injector is rotated, the respective oil injection nozzles are sequentially switched and communicated with the oil delivery channel. The oil gun for refilling oil in a transformer bushing provided by the present invention has strong applicability to different types of transformer bushings, can improve the oil refilling efficiency of the transformer bushing, and avoid waste caused by dripping and leaking oil during the oil refilling process.

Description

Technical Field

[0001] The present invention belongs to the technical field of transformer maintenance, and particularly relates to an oil gun for refilling oil in a transformer bushing. Background Art

[0002] In the power system, the transformer bushing not only plays a role in insulating against the ground, but also has the function of fixing the lead wire. Therefore, the importance of the transformer bushing is self-evident. The vast majority of the main transformer high-voltage side bushings are oil-immersed oil-filled equipment. During the daily maintenance of the transformer bushing, it is necessary to take samples from the bushing, which will gradually reduce the amount of oil in the bushing. Especially when the temperature drops in winter, due to the thermal expansion and contraction of the oil, the oil level in the bushing is often too low, seriously affecting the safe operation of the equipment and may also cause large-scale power outages.

[0003] According to the requirements of the power operation and maintenance regulations, to ensure the safe and stable operation of the transformer bushing, it is first necessary to ensure that there is sufficient oil in the bushing. At present, when refilling oil in the transformer bushing, the operator needs to climb onto the transformer and hold an oil gun to add oil into the bushing. Since the types of transformer bushings are diverse and the sizes of the oil injection holes of different bushings are also different, it is difficult for an oil gun of the same caliber to meet the refilling oil requirements of different transformers. Therefore, multiple spare parts (oil gun nozzles) need to be carried during maintenance, which not only makes the operation troublesome and the work efficiency low, but also is prone to oil dripping and leakage during the replacement of spare parts, resulting in serious waste. Summary of the Invention

[0004] The embodiment of the present invention provides an oil gun for refilling oil in a transformer bushing, aiming to improve the applicability of the oil gun for refilling oil in a transformer bushing to different types of transformer bushings, thereby improving the work efficiency and avoiding the waste phenomenon caused by oil dripping and leakage during the oil refilling process.

[0005] To achieve the above object, the technical solution adopted by the present invention is: providing an oil gun for refilling oil in a transformer bushing, including:

[0006] An oil gun body, including an oil gun handle and an oil gun head bent and extended from the top of the oil gun handle. An oil delivery channel is provided inside the oil gun handle and the oil gun head. One end of the oil delivery channel extends to the bottom end of the oil gun handle for connecting a fuel supply pipeline, and the other end extends to the extended end of the oil gun head;

[0007] An injector, sealingly and rotatably connected to the extended end of the oil gun head. A plurality of oil injection nozzles are spaced apart on the peripheral wall of the injector, and the diameters of the respective oil injection nozzles are different and are respectively used for being inserted into the oil injection holes of different types of transformer bushings in a matching manner. Among them, when the injector is rotated, the respective oil injection nozzles are sequentially switched and communicated with the oil delivery channel.

[0008] In a possible implementation, a sliding sleeve is provided on the oil gun head and extends along its axial direction. The inner circumferential wall of the extended sleeve is sealed and slidably contacts the circumferential wall of the extended end of the oil gun head. The extended end of the extended sleeve is closed, and an oil drain hole communicating with its inner cavity is provided on the circumferential wall of the closed end. The oiler is rotatably sleeved on the closed end of the extended sleeve, and the oil drain hole is aligned and communicated with one of the oil filling nozzles.

[0009] In some embodiments, an elastic positioning piece is embedded on the circumferential wall of the closed end of the extended sleeve, and the circumferential spacing between the elastic positioning piece and the oil drain hole along the extended sleeve is an integer multiple of the circumferential spacing between two adjacent oil injection nozzles along the extended sleeve. When the oil drain hole is aligned and connected with one of the oil injection nozzles, the elastic positioning piece is used to elastically engage with the inner hole of the corresponding other oil injection nozzle.

[0010] In some embodiments, a one-way air passage is provided on the peripheral wall of the lubricator between two adjacent oiling nozzles. When the lubricator is rotated until the one-way air passage is connected to the oil drain hole and the extension sleeve slides and extends toward the extended end of the oil gun head, the one-way air passage is used to allow outside air to enter the inner cavity of the extension sleeve.

[0011] Exemplarily, a plurality of first sealing rings are provided on the peripheral wall of the extended end of the oil gun head, and second sealing rings are provided on both sides of the oil drain hole between the oil injector and the extended sleeve.

[0012] For example, a locking member is screwed to one end of the extended sleeve facing the oil gun handle along its radial direction, and one end of the locking member passes through the side wall of the extended sleeve and abuts against the outer wall of the oil gun head.

[0013] In a possible implementation, a sealing plug is installed in the portion of the oil delivery channel located in the oil gun handle, which separates the oil delivery channel into an oil inlet channel and an oil outlet channel; a switch valve for connecting or blocking the oil inlet channel and the oil outlet channel is provided on the oil gun handle.

[0014] In some embodiments, an annular groove is provided on the periphery of the oil delivery channel in the oil gun handle, the annular groove extends along the axial direction of the oil delivery channel, and valve holes communicating with the annular groove are provided at the parts of the oil inlet channel and the oil outlet channel close to the plug; the switch valve includes:

[0015] The valve sleeve is connected to the annular groove by sliding along the axial direction of the annular groove, the inner peripheral wall of the valve sleeve is in sealing contact with the inner ring wall of the annular groove, and two oil grooves are arranged on the inner peripheral wall of the valve sleeve along the axial direction thereof;

[0016] The driving component is arranged in the oil gun handle, the operating end extends out of the side wall of the oil gun handle, and the output end is connected to the valve sleeve, which is used to drive the valve sleeve to slide until the two oil grooves are aligned or staggered with the two valve holes respectively.

[0017] Exemplarily, the drive assembly includes:

[0018] The rack is arranged on the outer wall of the valve sleeve along the axial direction of the valve sleeve;

[0019] The gear is rotatably connected inside the oil gun handle and meshes with the rack;

[0020] The worm gear is sleeved on the rotating shaft of the gear;

[0021] The worm is rotatably connected inside the oil gun handle along the axial direction of the rack and meshes with the worm gear;

[0022] The dial is sleeved on one end of the worm, and the edge of the dial extends out of the side wall of the oil gun handle;

[0023] Wherein, there is a one-way drive self-locking property between the worm gear and the worm.

[0024] For example, one end of the annular chute extends to the bottom wall of the oil gun handle, and an end cover is screwed at this end. A connection hole suitable for connecting a quick connector is provided on the end cover, and the connection hole communicates with the oil inlet channel.

[0025] The beneficial effect of an oil gun for refueling a transformer bushing provided by the present invention is that: compared with the prior art, for an oil gun for refueling a transformer bushing of the present invention, an injector is rotatably and sealingly connected to the end of the oil gun head. When refueling the transformer bushing, according to the size of the oil injection hole diameter of the transformer bushing, by rotating the injector, an oil injection nozzle matching the oil injection hole diameter is communicated with the oil delivery channel inside the oil gun body, and then the oil injection nozzle can be inserted into the oil injection hole for refueling. The operation is simple and convenient. And because there are multiple oil injection nozzles respectively matching the oil injection holes of different models of transformer bushings, only by rotating the injector can the oil injection nozzle be switched for refueling. Therefore, it can be applied to the refueling work of various transformer bushings, and can avoid the oil dripping phenomenon caused by disassembling, installing and replacing spare parts when refueling different transformer bushings, thereby avoiding oil waste. At the same time, the method of rotating and switching the oil injection nozzle can improve the work efficiency compared with the method of disassembling, installing and replacing. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of an oil gun for refueling a transformer bushing provided by an embodiment of the present invention;

[0027] Figure 2 is along Figure 1 the sectional structural schematic diagram along the A-A line in

[0028] Figure 3 is Figure 1 the partial enlarged structural schematic diagram at B in

[0029] In the figure: 10, oil gun body; 11, oil gun handle; 12, oil gun head; 121, first sealing ring; 13, oil delivery channel; 130, plug; 131, oil inlet channel; 132, oil outlet channel; 133, valve hole; 14, switch valve; 141, valve sleeve; 1410, oil groove; 142, drive assembly; 1421, rack; 1422, gear; 1423, worm gear; 1424, worm; 1425, dial; 15, annular chute; 151, metal spacer; 16, end cap; 161, connection hole; 20, oil injector; 21, oil injection nozzle; 22, extension sleeve; 221, oil drain hole; 222, elastic positioning member; 2221, ball; 2222, spring; 23, one-way ventilation channel; 24, second sealing ring. Detailed implementation mode

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer and more understandable, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] It should be understood that an oil gun for refueling a transformer bushing provided in this embodiment needs to be used in cooperation with an oil tank and an oil pump. The transformer oil in the oil tank is pumped into the oil gun through the oil pump, so as to add or replenish oil to the transformer bushing.

[0032] Please refer to Figure 1 and Figure 2 , and an oil gun for refueling a transformer bushing provided by the present invention will be described. The oil gun for refueling a transformer bushing includes an oil gun body 10 and an oil injector 20; the oil gun body 10 includes an oil gun handle 11 and an oil gun head 12 bent and extended from the top of the oil gun handle 11. An oil delivery channel 13 is provided inside the oil gun handle 11 and the oil gun head 12. One end of the oil delivery channel 13 extends to the bottom end of the oil gun handle 11 for connecting a fuel supply pipeline, and the other end extends to the extended end of the oil gun head 12; the oil injector 20 is hermetically and rotatably connected to the extended end of the oil gun head 12. A plurality of oil injection nozzles 21 are distributed at intervals on the peripheral wall of the oil injector 20. The diameters of the oil injection nozzles 21 are different and are respectively used to match and insert into the oil injection holes of different models of transformer bushings. Among them, when the oil injector 20 is rotated, the oil injection nozzles 21 are sequentially switched and communicated with the oil delivery channel 13.

[0033] First of all, it should be noted that the oil gun body 10 can be of an integrally formed structure or a split structure. In order to reduce the weight of the oil gun body 10 and thus reduce the labor intensity of maintenance personnel during refueling operations, a split structure is preferably adopted here. That is, the oil gun handle 11 is injection-molded from a plastic material, and the oil gun head 12 is made of a metal pipe. After the oil gun head 12 is inserted into the oil gun handle 11, it is integrally formed by heating and plastic welding. In order to ensure operation convenience, a stop valve can be provided on the oil delivery channel 13;

[0034] In addition, the rotational connection between the oil injector 20 and the oil gun head 12 should ensure the sealing performance to avoid oil leakage when the oil injection nozzle 21 is rotated for switching. Specifically, a gasket / ring and a sealing slip ring (similar to the form of a piston ring) can be provided between the inner hole of each oil injection nozzle 21 and the peripheral wall of the oil gun head 12.

[0035] Compared with the prior art, the oil gun for refueling a transformer bushing provided in this embodiment, that is, the oil gun for refueling a transformer bushing of the present invention, has an oil injector 20 rotatably and sealingly connected to the end of the oil gun head 12. When refueling the transformer bushing, it can be aimed at the oil injection hole diameter of the transformer bushing. By rotating the oil injector 20, the oil injection nozzle 21 matching the oil injection hole diameter is communicated with the oil delivery channel 13 inside the oil gun body 10, and then the oil injection nozzle 21 can be inserted into the oil injection hole for refueling. The operation is simple and convenient. And because there are multiple oil injection nozzles 21 respectively matching the oil injection holes of different types of transformer bushings, only by rotating the oil injector 20 can the oil injection nozzle 21 be switched for refueling. Therefore, it can be applied to the refueling work of various transformer bushings, and can avoid the oil leakage phenomenon caused by disassembling and replacing spare parts when refueling different transformer bushings, thus avoiding oil waste. At the same time, the method of rotating and switching the oil injection nozzle 21 can improve the work efficiency compared with the method of disassembling and replacing.

[0036] In some embodiments, please refer to Figure 1 and Figure 2 , a lengthening sleeve 22 extending along its axial direction is slidably sleeved on the oil gun head 12. The inner peripheral wall of the lengthening sleeve 22 is in sealing and sliding contact with the peripheral wall of the extending end of the oil gun head 12. The extending end of the lengthening sleeve 22 is closed, and an oil discharge hole 221 communicating with its inner cavity is provided on the peripheral wall of the closed end. The oil injector 20 is rotatably sleeved on the closed end of the lengthening sleeve 22, and the oil discharge hole 221 is aligned and communicated with one of the oil injection nozzles 21.

[0037] Since the inner peripheral wall of the extended sleeve 22 is in sealing contact with the peripheral wall of the extended end of the oil gun head 12, a sealed cavity is formed between the inner wall of the closed end of the extended sleeve 22 and the end wall of the extended end of the oil gun head 12, and is communicated with the oil injection nozzle 21 rotated to the corresponding position through the oil discharge hole 221. Therefore, when refueling, the oil liquid enters the sealed cavity from the oil transmission channel 13, and then enters the oil injection nozzle 21 from the oil discharge hole 221. When it is necessary to switch the oil injection nozzle 21, only need to rotate the oil injector 20 to align the corresponding oil injection nozzle 21 with the oil discharge hole 221. It should be understood here that when one of the oil injection nozzles 21 is communicated with the oil discharge hole 221, the remaining oil discharge nozzles are blocked by the peripheral wall of the extended end of the oil gun head 12. Therefore, only one oil injection nozzle 21 is always in the working state.

[0038] When the transformer bushing is actually refueled and replenished, due to the limited operating space, the maintenance personnel often cannot maintain a posture of being in close contact with the transformer bushing. In view of this situation, in this embodiment, an extended sleeve 22 is provided on the oil gun head 12. When the distance between the transformer bushing and the maintenance personnel is far, by sliding the extended sleeve 22 in the direction away from the oil gun handle 11, the distance between the oil injector 20 located at the closed end of the extended sleeve 22 and the oil gun handle 11 is lengthened to meet the long-distance refueling and replenishing requirements, thereby reducing the operation difficulty and avoiding action deformation caused by inconvenient operation, which may lead to the oil injection nozzle 21 being unable to maintain the state of aligning with the oil injection hole of the transformer bushing, and further resulting in oil leakage. It can reduce the problem of oil waste and improve the refueling and replenishing operation efficiency of the transformer bushing.

[0039] In this embodiment, refer to Figure 1 and Figure 2 , an elastic positioning member 222 is embedded on the peripheral wall of the closed end of the extended sleeve 22. The circumferential spacing between the elastic positioning member 222 and the oil discharge hole 221 along the extended sleeve 22 is an integer multiple of the circumferential spacing between two adjacent oil injection nozzles 21 along the extended sleeve 22. When the oil discharge hole 221 is aligned and communicated with one of the oil injection nozzles 21, the elastic positioning member 222 is used for elastically clamping with the inner hole of the corresponding other oil injection nozzle 21.

[0040] Specifically, the optional structure of the elastic positioning member 222 is as shown in Figure 2 : A mounting blind hole is provided on the peripheral wall of the closed end of the extended sleeve 22. A ball 2221 is provided in the mounting blind hole, and a spring 2222 is provided between the ball 2221 and the bottom wall of the mounting blind hole; the ball 2221 is pressed against the inner peripheral wall of the oil injector 20 or the inner hole port of one of the oil injection nozzles 21 under the elastic force of the spring 2222.

[0041] Since the circumferential spacing between the elastic positioning member 222 and the oil drain hole 221 along the extended sleeve 22 is an integer multiple of the circumferential spacing between two adjacent oiling nozzles 21 along the extended sleeve 22, that is, when one of the oiling nozzles 21 is aligned and connected with the oil drain hole 221, the elastic positioning member 222 will inevitably be aligned with the inner hole of the other oiling nozzle 21. At this time, the marble 2221 is partially sunken at the end of the inner hole of the oiling nozzle 21 under the elastic thrust of the spring 2222, thereby forming a clamping positioning state. On the one hand, it is convenient for the operator to grasp whether the corresponding oiling nozzle 21 is accurately aligned with the oil drain hole 221. On the other hand, it can avoid the oiler 20 from automatically rotating during the oil filling process, causing the oiling nozzle 21 and the oil drain hole 221 to be misaligned, thereby causing the oil discharge to slow down or stop, thereby ensuring that the oil filling process is smooth and efficient.

[0042] Of course, when it is necessary to switch the oiling nozzle 21, since the ball 2221 is a spherical structure, the rotational force on the oiler 20 itself can make the port edge position of the inner hole of the oiling nozzle 21 press against the ball 2221, thereby overcoming the elastic force of the spring 2222 and retracting into the embedded blind hole. After the oiling nozzle 21 is staggered with the embedded blind hole, the ball 2221 presses against the inner circumferential wall of the oiler 20 until the next oiling nozzle 21 is aligned with the embedded blind hole, and the ball 2221 automatically pops out and re-forms a snap-fit ​​state with the inner hole of the oiling nozzle 21. The operation is simple and convenient, and can improve the alignment accuracy of each oiling nozzle 21 and the oil drain hole 221, ensuring smooth discharge of oil during the oiling and replenishing process, thereby improving the oil replenishment efficiency.

[0043] In some embodiments, please combine Figure 1 and Figure 2 A one-way air passage 23 is provided on the peripheral wall of the lubricator 20 between two adjacent lubricating nozzles 21. When the lubricator 20 rotates until the one-way air passage 23 is connected to the oil drain hole 221 and the extension sleeve 22 slides and extends toward the extended end of the oil gun head 12, the one-way air passage 23 is used to allow outside air to enter the inner cavity of the extension sleeve 22.

[0044] For details, see Figure 2 The one-way air passage 23 is a one-way valve embedded in the side wall of the oiler 20. The air inlet end of the one-way valve is located on the outer wall of the oiler 20, and the air outlet end is located on the inner wall of the oiler 20. When it is rotated to be radially aligned with the oil drain hole 221, the air outlet end of the one-way valve is connected to the oil drain hole 221.

[0045] When performing the oil replenishment operation, maintenance personnel need to hold an oil gun for high-altitude operation, and the fuel tank supplying oil to the oil gun needs to be placed on the ground. Therefore, the oil gun and the fuel tank need to be connected through an oil pipe. For a transformer bushing with a relatively high height, the vertical height from it to the ground is usually more than five meters. Therefore, the length of the oil pipe is relatively long. After the oil replenishment is completed, a large amount of transformer oil still remains in the oil pipe. To avoid waste, usually, the high-altitude operation personnel need to hold the oil gun and wait for the transformer oil in the oil pipe to flow back into the fuel tank under the action of gravity before they can descend to the ground. Since the inner hole of the injection nozzle 21 is small, the speed of replenishing gas into the oil pipe is slow, which results in a very slow backflow speed of the transformer oil in the oil pipe into the fuel tank, thus affecting the operation efficiency. To increase the backflow speed of the transformer oil in the oil pipe, the one-way ventilation channel 23 can be used for assistance. The specific working process is as follows:

[0046] After the oil replenishment is completed, rotate the oil injector 20 to align the outlet end of the one-way valve (i.e., the above-mentioned one-way ventilation channel 23) with the oil discharge hole 221. At this time, if the extension sleeve 22 is in the extended state, directly push the extension sleeve 22 in the direction of the oil gun handle 11, thereby squeezing the space between the closed end of the extension sleeve 22 and the extended end of the oil gun head 12, and then generating high pressure in the oil delivery channel 13, so that the residual transformer oil in the oil pipe quickly drains back into the fuel tank under the action of high pressure. Of course, usually, pushing the extension sleeve 22 once cannot completely drain the transformer oil in the oil pipe. Therefore, it is necessary to pull the extension sleeve 22 in the direction away from the oil gun handle 11. At this time, the outside air enters the inside of the extension sleeve 22 through the one-way valve, which can ensure that the extension sleeve 22 is smoothly elongated. After elongating to the limit position, push the extension sleeve 22 in the reverse direction. At this time, since the gas in the extension sleeve 22 cannot pass through the one-way valve, it can squeeze the transformer oil in the oil pipe through the oil delivery channel 13. Repeat the above actions until the oil in the oil pipe completely flows back into the fuel tank. It should be understood that if the extension sleeve 22 is in the retracted state when the oil replenishment is completed (that is, when the distance between the operation position of the maintenance personnel and the transformer bushing is relatively close and there is no need for the extension sleeve 22 to extend for the oil replenishment operation), at this time, just align the one-way valve with the oil discharge hole 221, first elongate the extension sleeve 22, and then push back the extension sleeve 22, and repeat such actions until all the transformer oil in the oil pipe flows back into the fuel tank.

[0047] By setting the one-way ventilation channel 23, the extension sleeve 22 can cooperate with the extended end of the oil gun head 12 to assist in liquid drainage after the oil replenishment is completed, so that the transformer oil in the oil pipe can quickly flow back into the fuel tank, avoiding waste caused by oil residue in the oil pipe, and improving the operation efficiency.

[0048] Exemplarily, refer to Figure 1, a plurality of first sealing rings 121 are sleeved on the peripheral wall of the extended end of the oil gun head 12, and second sealing rings 24 are provided on both sides of the oil discharge hole 221 between the oil injector 20 and the extended sleeve 22.

[0049] The sealing effect between the extended end of the oil gun head 12 and the inner wall of the extended sleeve 22 is achieved by sleeving the first sealing ring 121, thereby preventing the leakage of transformer oil during the process of passing through the inner cavity of the extended sleeve 22 from the oil transmission channel 13 and then entering the oil discharge hole 221; the second sealing rings 24 on both sides of the oil discharge hole 221 can prevent the leakage of oil when the oil enters the corresponding oil injection nozzle 21 from the oil discharge hole 221; specifically, the first sealing ring 121 and the second sealing ring 24 can be made of corrosion-resistant rubber rings, or polytetrafluoroethylene plastic rings, or a combined structure of both, and the specific structure is not limited here.

[0050] For example, refer to Figure 1 , a locking member is screwed on the end of the extended sleeve 22 facing the oil gun handle 11 along its radial direction, and one end of the locking member passes through the side wall of the extended sleeve 22 and abuts against the outer wall of the oil gun head 12. It is only necessary to loosen the locking member (specifically, a set screw) when sliding the extended sleeve 22, and tighten the locking member after the extended sleeve 22 slides into place to prevent the relative movement between the extended sleeve 22 and the oil gun head 12. The operation is simple and convenient, and can ensure the stability of oil replenishment.

[0051] In some possible implementation manners, please refer to Figure 1 and Figure 3 , a plug 130 is hermetically embedded in the part of the oil transmission channel 13 located in the oil gun handle 11, and the plug 130 divides the oil transmission channel 13 into an oil inlet channel 131 and an oil outlet channel 132; a switch valve 14 for connecting or blocking the oil inlet channel 131 and the oil outlet channel 132 is provided on the oil gun handle 11.

[0052] For convenient processing, after the oil gun handle 11 is manufactured and the oil transmission channel 13 is formed together (it can be integrally formed by injection molding, which is simple and convenient), the plug 130 is embedded into the oil transmission channel 13 from the bottom end of the oil gun handle 11, thereby dividing the oil transmission channel 13 into the oil inlet channel 131 and the oil outlet channel 132, and then the oil inlet channel 131 and the oil outlet channel 132 are connected by a switch. When the switch valve 14 is in the open state, the oil inlet channel 131 and the oil outlet channel 132 are connected, and when the switch valve 14 is in the closed state, the oil inlet channel 131 and the oil outlet channel 132 are blocked, thus facilitating the control by high-altitude operators.

[0053] In the embodiment, please refer to Figure 3, an annular chute 15 is provided around the oil delivery channel 13 inside the oil gun handle 11. The annular chute 15 extends along the axial direction of the oil delivery channel 13. Valve holes 133 communicating with the annular chute 15 are provided at the parts of the oil inlet channel 131 and the oil outlet channel 132 close to the plug 130.

[0054] The on-off valve 14 includes a valve sleeve 141 and a driving assembly 142. The valve sleeve 141 is slidably connected to the annular chute 15 along the axial direction of the annular chute 15. The inner peripheral wall of the valve sleeve 141 is in sealing contact with the inner ring wall of the annular chute 15. Two oil grooves 1410 are spaced apart along the axial direction on the inner peripheral wall of the valve sleeve 141. The driving assembly 142 is arranged inside the oil gun handle 11. The operating end extends out of the side wall of the oil gun handle 11, and the output end is connected to the valve sleeve 141 for driving the valve sleeve 141 to slide so that the two oil grooves 1410 are respectively aligned with or staggered from the two valve holes 133.

[0055] It should be noted that, in order to ensure the sealing performance between the on-off valve 14 and the oil delivery channel 13, a section of the oil delivery channel 13 located inside the oil gun handle 11 is formed by a section of metal spacer sleeve 151 (inner hole) embedded in the oil gun handle 11. The outer peripheral wall of the metal spacer sleeve 151 serves as the inner ring surface of the annular chute 15. During processing, a hole is machined based on the diameter of the outer ring surface of the annular chute 15, and then the metal spacer sleeve 151 is embedded into the hole so that the outer peripheral wall of the metal spacer sleeve 151 and the peripheral wall of the hole jointly form the annular chute 15 structure. The valve sleeve 141 is made of a metal sleeve to ensure the fitting sealing between the inner peripheral wall of the valve sleeve 141 and the inner ring surface of the annular chute 15.

[0056] Specifically, in this embodiment, the optional structure of the driving assembly 142 is that the driving assembly 142 includes a rack 1421, a gear 1422, a worm 1424, a worm gear 1423, and a dial 1425. The rack 1421 is arranged on the outer wall of the valve sleeve 141 along the axial direction of the valve sleeve 141. The gear 1422 is rotatably connected inside the oil gun handle 11 and meshes with the rack 1421. The worm gear 1423 is sleeved on the rotating shaft of the gear 1422. The worm 1424 is rotatably connected inside the oil gun handle 11 along the axial direction of the rack 1421 and meshes with the worm gear 1423. The dial 1425 is sleeved on one end of the worm 1424, and the edge of the dial 1425 extends out of the side wall of the oil gun handle 11. Among them, there is a one-way transmission self-locking property between the worm gear 1423 and the worm 1424.

[0057] When the maintenance personnel are replenishing oil, the worm 1424 is driven to rotate by turning the dial wheel 1425, thereby driving the worm wheel 1423 to rotate. Since the worm wheel 1423 and the gear 1422 are mounted on the same shaft, the gear 1422 will rotate together with the worm wheel 1423, thereby driving the rack 1421 to move along the axial direction of the valve sleeve 141, and then driving the valve sleeve 141 to slide in the annular groove 15. When the two oil grooves 1410 on the valve sleeve 141 are respectively aligned with the valve holes 133 on the oil inlet channel 131 and the oil outlet channel 132, since the two oil grooves 1410 are connected to each other, the oil inlet channel 131 and the oil outlet channel 132 can be connected, and the oil can enter the corresponding oil injection nozzle 21 through the oil delivery channel 13 for oil replenishment;

[0058] When the oil replenishment is completed, the dial wheel 1425 is turned in the reverse direction to drive the worm 1424 to rotate in the reverse direction, and the worm gear 1423 is driven to rotate by the worm 1424. Since the gear 1422 and the worm gear 1423 are mounted on the same shaft, the gear 1422 rotates together with the worm gear 1423 to drive the rack 1421 to move in the reverse direction, thereby driving the valve sleeve 141 to slide to a position where the oil groove 1410 and the valve hole 133 are offset, and the oil in the oil inlet passage 131 can no longer enter the oil groove 1410 through the valve hole 133, thereby blocking the oil inlet passage 131 and the oil outlet passage 132;

[0059] Since the worm wheel 1423 and the worm 1424 have a one-way transmission self-locking property, that is, the rotation of the worm 1424 can drive the worm wheel 1423 to rotate, while the rotation of the worm wheel 1423 cannot drive the worm 1424 to rotate. Therefore, after the dial wheel 1425 drives the valve sleeve 141 to move into place, the automatic slip of the valve sleeve 141 can be avoided. Therefore, the operator only needs to hold the oil gun handle 11 to replenish the oil, and there is no need to control the switching state of the switch valve 14 at all times, thereby reducing the labor intensity of the operator and facilitating the operator to stably hold the oil gun handle 11 to operate, thereby avoiding oil dripping caused by deformation of the movement and reducing waste.

[0060] Optionally, in this embodiment, please refer to Figure 3 One end of the annular slide groove 15 extends to the bottom end wall of the oil gun handle 11, and the end is screwed with an end cover 16, and the end cover 16 is provided with a connecting hole 161 suitable for connecting a quick connector, and the connecting hole 161 is connected to the oil inlet channel 131. The structure is simple and the connection is convenient.

[0061] Specifically, when the valve sleeve 141 slides to the point where the two oil grooves 1410 are aligned with the two valve holes 133 respectively, the top end of the valve sleeve 141 abuts against the top end of the annular groove 15; when the valve sleeve 141 slides in the opposite direction to the point where the two oil grooves 1410 are offset from the two valve holes 133 respectively, the bottom end of the valve sleeve 141 abuts against the end wall of the annular groove 15 that is screwed into the end cover 16.

[0062] By using the abutting and positioning effect between the top wall of the annular chute 15 and the screwing-in end of the end cover 16, it is possible to ensure the accurate alignment or misalignment of the oil groove 1410 and the valve hole 133, which facilitates the operator to accurately grasp the opening and closing states of the on-off valve 14 when turning the dial 1425.

[0063] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. An oil gun for refilling oil in a transformer bushing, characterized in that, it includes: An oil gun body, including an oil gun handle and an oil gun head bent and extended from the top of the oil gun handle. An oil delivery channel is provided inside the oil gun handle and the oil gun head. One end of the oil delivery channel extends to the bottom end of the oil gun handle for connecting a fuel supply pipeline, and the other end extends to the extended end of the oil gun head; An injector, sealingly and rotatably connected to the extended end of the oil gun head. A plurality of oil injection nozzles are spaced apart on the peripheral wall of the injector. The diameters of the oil injection nozzles are different and are respectively used to be inserted into the oil injection holes of different models of transformer bushings in a matching manner. Among them, when the injector rotates, the oil injection nozzles are sequentially switched and communicated with the oil delivery channel; A lengthening sleeve is slidably sleeved on the oil gun head and extends along its axis. The inner peripheral wall of the lengthening sleeve is in sealing and sliding contact with the peripheral wall of the extended end of the oil gun head. The extended end of the lengthening sleeve is closed, and an oil discharge hole communicating with its inner cavity is provided on the peripheral wall of the closed end. The injector is rotatably sleeved on the closed end of the lengthening sleeve, and the oil discharge hole is aligned and communicated with one of the oil injection nozzles; A one-way ventilation channel is provided on the peripheral wall of the injector between two adjacent oil injection nozzles. When the injector rotates to make the one-way ventilation channel communicate with the oil discharge hole and the lengthening sleeve slides and extends toward the extended end of the oil gun head, the one-way ventilation channel is used to introduce external air into the inner cavity of the lengthening sleeve; The one-way ventilation channel is used to cooperate with the lengthening sleeve to quickly discharge the residual transformer oil in the fuel supply pipeline back to the fuel tank under high pressure.

2. An oil gun for refilling oil in a transformer bushing according to claim 1, characterized in that, An elastic positioning member is embedded on the peripheral wall of the closed end of the lengthening sleeve. The circumferential distance between the elastic positioning member and the oil discharge hole along the lengthening sleeve is an integer multiple of the circumferential distance between two adjacent oil injection nozzles along the lengthening sleeve. When the oil discharge hole is aligned and communicated with one of the oil injection nozzles, the elastic positioning member is used to elastically clamp the inner hole of the corresponding other oil injection nozzle.

3. An oil gun for refilling oil in a transformer bushing according to claim 1, characterized in that, A plurality of first sealing rings are sleeved on the peripheral wall of the extended end of the oil gun head. Second sealing rings are provided on both sides of the oil discharge hole between the injector and the lengthening sleeve.

4. An oil gun for refilling oil in a transformer bushing according to claim 1, characterized in that, A locking member is screwed on the end of the lengthening sleeve facing the oil gun handle along its radial direction. One end of the locking member passes through the side wall of the lengthening sleeve and abuts against the outer wall of the oil gun head.

5. An oil gun for refilling oil in a transformer bushing according to any one of claims 1-4, characterized in that, A plug is hermetically embedded in the part of the oil delivery channel located in the oil gun handle. The plug divides the oil delivery channel into two parts: an oil inlet channel and an oil outlet channel; A switch valve for communicating or blocking the oil inlet channel and the oil outlet channel is provided on the oil gun handle.

6. An oil gun for refilling oil in a transformer bushing according to claim 5, characterized in that, An annular chute is provided around the oil delivery channel inside the oil gun handle. The annular chute extends along the axial direction of the oil delivery channel. Valve holes communicating with the annular chute are provided at positions of the oil inlet channel and the oil outlet channel close to the plug; The switching valve includes: A valve sleeve, which is slidably connected to the annular chute along the axial direction of the annular chute. The inner peripheral wall of the valve sleeve is in sealing contact with the inner ring wall of the annular chute. Two oil grooves are spaced apart along the axial direction on the inner peripheral wall of the valve sleeve; A driving assembly, which is arranged inside the oil gun handle. The operating end extends out of the side wall of the oil gun handle, and the output end is connected to the valve sleeve for driving the valve sleeve to slide so that the two oil grooves are respectively aligned or staggered with the two valve holes.

7. An oil gun for refueling a transformer bushing as described in claim 6, characterized in that the driving assembly includes: A rack, which is arranged on the outer wall of the valve sleeve along the axial direction of the valve sleeve; A gear, which is rotatably connected inside the oil gun handle and meshes with the rack; A worm wheel, which is sleeved on the rotating shaft of the gear; A worm, which is rotatably connected inside the oil gun handle along the axial direction of the rack and meshes with the worm wheel; A dial, which is sleeved on one end of the worm, and the edge of the dial extends out of the side wall of the oil gun handle; wherein, there is a one-way transmission self-locking property between the worm wheel and the worm.

8. An oil gun for refueling a transformer bushing as described in claim 6, characterized in that One end of the annular chute extends to the bottom wall of the oil gun handle, and an end cover is screwed at this end. A connection hole adapted to connect a quick connector is provided on the end cover, and the connection hole communicates with the oil inlet channel.

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