Safe small and micro oil-immersed high-frequency transformer

Abstract

The utility model discloses a safe type small and micro oil-immersed high-frequency transformer, primary coil, core, secondary coil are located in the oil tank inner chamber, the thermistor is pasted to the oil tank side, the upper end through -hole of oil tank is connected with the lower end of telescopic pipe, and the upper end of telescopic pipe is connected with the lower end of upper cover, and the lower end of support foot is connected with the upper end outer edge of oil tank, and the upper end is connected with the lower side outer edge of emergency stop switch. Emergency stop switch is connected with signal input end, and thermistor is connected in series, thermistor is connected in series with primary coil, and primary coil is connected with signal input end. Secondary coil and primary coil are same core coil, and signal output end is connected. The telescopic pipe of the utility model can replace the radiating fin, improve the heat dissipation, and the thermistor acts as temperature controller, improve the thermal stability, can also regulate and control the power of the utility model, prevent overload, when thermistor fails, telescopic pipe can push upper cover and trigger emergency stop switch, start emergency stop. The utility model has good heat dissipation, good overload prevention and good thermal stability, and is more conducive to the small and micro oil-immersed high-frequency transformer.

Description

Technical Field

[0001] This utility model relates to the field of transformer safety protection technology, specifically to a miniaturized oil-immersed high-frequency transformer. Background Technology

[0002] High-frequency transformers often use epoxy resin-cast dry insulation. However, epoxy resin has low thermal conductivity, which is not conducive to efficient heat dissipation of the transformer. In addition, high-frequency transformers operate at high frequencies and have high loss densities, resulting in a much higher heat generation per unit volume than traditional power frequency transformers. When the heat generated inside a high-frequency transformer cannot be effectively dissipated, the internal temperature will rise, affecting the reliability and lifespan of the insulation materials. Air cooling is the most common heat dissipation method, but traditional air cooling methods have limited effectiveness, and the air cooling device is relatively large in size, power consumption, and noise. When the air cooling device draws in cold air from outside the equipment for air cooling, dust and moisture will also enter the equipment and adhere to the transformer. Over time, the accumulated dust and moisture will affect the insulation and heat dissipation of the circuit board components, easily leading to failure due to excessive temperature and reduced insulation. This problem is even more serious in production workshops or construction sites with high humidity and heavy dust. How to balance dust prevention and moisture prevention when air-cooling high-frequency transformers has become a thorny issue.

[0003] As circuit boards for small devices develop towards integration, miniaturization, and high precision, the requirements for miniaturization and compact installation space of related high-frequency transformers are becoming increasingly stringent. However, the miniaturization of high-frequency transformers, due to their small size and surface area, affects heat dissipation. Furthermore, due to the compact installation space, there is not enough space to configure a separate fan. If a custom-made miniature fan is used, the fan itself is too small and has heat dissipation problems, making the heat dissipation problem even more serious. Although the open structure is conducive to heat dissipation, the loss of the shielding cover will cause power loss due to magnetic leakage and interference with other components, and noise is also difficult to shield.

[0004] Oil-immersed high-frequency transformers have excellent heat dissipation, with transformer oil acting as a heat transfer medium for efficient cooling and stable operation under short-term overload. Their enclosed structure also effectively prevents magnetic leakage. Transformer oil has a certain buffering and shock absorption effect, which can reduce noise to some extent, making them very suitable for miniaturization of high-frequency transformers. However, due to their enclosed structure, the temperature of the transformer oil inside rises due to heat accumulation during long-term high-load operation. If heat dissipation is not timely, combined with other environmental factors (such as lightning strikes, overloads, short circuits, etc.), it is easy to cause a risk of deflagration. Miniature oil-immersed high-frequency transformers are difficult to prevent explosion by thickening the shell. Although they can be explosion-proofed by pressure relief protection devices, the handling of oil leakage during pressure relief is complicated and can easily cause fires in other components, resulting in poor safety.

[0005] How to balance dust prevention, moisture prevention, overload protection, and thermal stability of small and micro oil-immersed high-frequency transformers has become an unsolved problem. Utility Model Content

[0006] To address the shortcomings of existing technologies, this utility model provides a miniature oil-immersed high-frequency transformer that can simultaneously provide dustproof, moisture-proof, overload-proof, thermally stable, noise-reducing, and fire-resistant properties.

[0007] The specific solution of this utility model is as follows: A safe and miniaturized oil-immersed high-frequency transformer includes: an emergency stop switch, support legs, a top cover, a telescopic tube, a primary coil, an iron core, a secondary coil, an oil tank, and a thermistor; the primary coil is sleeved on one side of the iron core, and the secondary coil is sleeved on the other side of the iron core, with the primary coil, iron core, and secondary coil all located inside the oil tank; the thermistor is attached to the side of the oil tank; the upper end of the oil tank has a through hole that connects to the lower end of the telescopic tube, and the upper end of the telescopic tube is sleeved to the inner side of the lower end of the top cover; the lower end of the support legs is connected to the outer edge of the upper end of the oil tank, and the upper end is connected to the outer edge of the lower side of the emergency stop switch, supporting the emergency stop switch.

[0008] The emergency stop switch is a normally closed push-button switch, with the button located at the bottom center.

[0009] The lower outer edge of the top cover has a circular step, which is made of brass and tin-plated on the outside.

[0010] The telescopic tube includes: an arc-shaped steel wire, a tension spring, and an elastic corrugated tube. There are two arc-shaped steel wires, which are located at the upper and lower openings of the elastic corrugated tube respectively. The two ends of the arc-shaped steel wires are fixedly connected to the openings, and the arc faces the inside of the elastic corrugated tube. The hooks at both ends of the tension spring are respectively suspended from the two arc-shaped steel wires.

[0011] The arc-shaped steel wire can be made by hot bending of rigid steel wire or by cutting steel wire retaining rings into sections.

[0012] The tension spring can be selected from the GB / T1973.2 series or the GB / T4142 series.

[0013] The elastic corrugated pipe has short straight pipes at both ends and a corrugated pipe in the middle. It is made of elastic brass and tin-plated on the outside.

[0014] The oil tank has a through hole at the center of the upper end for connecting the lower end of the telescopic tube, and an external grounding wire made of brass with tin plating on the outside.

[0015] The thermistor is a positive temperature coefficient thermistor.

[0016] The emergency stop switch input terminal is connected to an external signal input terminal. The emergency stop switch output terminal is connected in series with the thermistor input terminal. The thermistor output terminal is connected in series with the primary coil input terminal. The primary coil output terminal is connected to an external signal input terminal. The secondary coil is a coil with the same core as the primary coil and is connected to an external signal output terminal.

[0017] Compared with existing related technologies, this utility model has the following advantages: This invention has good heat dissipation: the elastic corrugated tube of this invention is made of brass and has a surface area much larger than that of a straight tube, so it can replace a heat sink as a heat dissipation tube.

[0018] This invention features good thermal stability: the thermistor is attached to the side of the oil tank, acting as a temperature controller. When the primary coil, iron core, and secondary coil heat up the transformer oil, the heat is transferred to the oil tank, and then to the thermistor. This thermistor is a positive temperature coefficient thermistor; as the temperature rises, its resistance increases. Because the thermistor is connected in series with the primary coil, the increased resistance leads to a higher voltage drop, a decrease in circuit current, a decrease in the current and operating voltage of the primary coil, a decrease in the eddy current in the iron core, and a corresponding decrease in the current and operating voltage of the secondary coil. This reduces the power of the primary coil, iron core, and secondary coil, thus reducing heat generation. After the primary coil, iron core, and secondary coil cool down through heat dissipation, the temperature of the transformer oil and oil tank decreases, the thermistor resistance decreases, the voltage drop decreases, the circuit current increases, and the current and operating voltage of the primary coil recover. The eddy current in the iron core recovers, and the current and operating voltage of the secondary coil also recover accordingly, restoring the power of the primary coil, iron core, and secondary coil.

[0019] This invention has a good overload protection effect: It can regulate the power of the primary coil, iron core, and secondary coil through a thermistor to prevent overload. When the load exceeds the thermistor's regulation range and the thermistor fails, the transformer oil in the tank and telescopic tube evaporates more rapidly. Driven by the vapor expansion pressure, the telescopic tube extends, triggering the emergency stop switch on the top cover. This invention provides an emergency stop and unloads the load, preventing the tank and telescopic tube from rupturing. After the emergency stop, the primary coil, iron core, and secondary coil no longer heat up. After the transformer oil cools down through heat dissipation, the vapor begins to liquefy, the pressure drops, and the tension spring acts as a reset spring to pull the telescopic tube to retract. The emergency stop switch is a normally closed push-button switch. After the telescopic tube retracts, it automatically resets and reconnects, and the invention resumes operation.

[0020] This utility model can simultaneously prevent dust, moisture, and electromagnetic leakage: the upper end of the telescopic tube is glued and sealed to the upper cover, and the lower end of the telescopic tube is sleeved on the upper through hole of the oil tank and brazed and sealed to form a closed structure that is dustproof and moistureproof; the upper cover, telescopic tube, and oil tank are all tin-plated to effectively prevent electromagnetic leakage; the oil tank is grounded to short-circuit the induced current of the telescopic tube and the oil tank to the ground, preventing the formation of eddy currents and further reducing electromagnetic leakage.

[0021] This invention has good fire resistance: the transformer oil contains 52# chlorinated paraffin flame retardant, which can prevent fire caused by oil leakage (transformer oil is insulating oil and will not cause short circuit due to oil leakage), and can also play a certain flame retardant role when other components catch fire.

[0022] The present invention has a good noise reduction effect: the transformer oil of the present invention is mixed with 52# chloride, which can effectively increase the viscosity. The viscous oil can better convert the vibration into heat energy during the vibration process, thus achieving the effect of vibration reduction and noise reduction. The tension spring and elastic bellows of the telescopic tube are both spring-type shock absorbers, which can effectively buffer and reduce vibration, thus achieving the effect of vibration reduction and noise reduction.

[0023] This invention has good heat dissipation, good overload protection, and good thermal stability, which is more conducive to the miniaturization of high-frequency transformers. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the telescopic tube structure of this utility model; Figure 3 This is the circuit diagram of this utility model. Detailed Implementation

[0025] like Figure 1 , Figure 2 As shown, a safety-type miniaturized oil-immersed high-frequency transformer includes: an emergency stop switch 1, a support leg 2, a top cover 3, a telescopic tube 4, a primary coil 5, an iron core 6, a secondary coil 7, an oil tank 8, and a thermistor 9. The primary coil 5 is sleeved on one side of the iron core 6, and the secondary coil 7 is sleeved on the other side of the iron core 6. The primary coil 5, the iron core 6, and the secondary coil 7 are all located inside the oil tank 8. The thermistor 9 is attached to the side of the oil tank 8. The upper end of the oil tank 8 has a through hole that connects to the lower end of the telescopic tube 4, and the upper end of the telescopic tube 4 is sleeved to the inner side of the lower end of the top cover 3. The lower end of the support leg 2 is connected to the outer edge of the upper end of the oil tank 8, and the upper end is connected to the outer edge of the lower side of the emergency stop switch 1, supporting the emergency stop switch 1.

[0026] The emergency stop switch 1 is a normally closed push-button switch, with the button located at the center of the lower end.

[0027] The lower outer edge of the upper cover 3 has a circular step, which is made of brass and tin-plated on the outside.

[0028] The telescopic tube 4 includes: an arc steel wire 4-1, a tension spring 4-2, and an elastic corrugated tube 4-3. There are two arc steel wires 4-1, which are located at the upper and lower openings of the elastic corrugated tube 4-3 respectively. The two ends of the arc steel wire 4-1 are fixedly connected to the openings, and the arc faces the inside of the elastic corrugated tube 4-3. The hooks at both ends of the tension spring 4-2 are respectively suspended from the two arc steel wires 4-1.

[0029] The circular arc steel wire 4-1 can be made by hot bending of rigid steel wire or by cutting steel wire retaining rings into sections.

[0030] The tension spring 4-2 can be selected from the GB / T1973.2 series or the GB / T4142 series.

[0031] The elastic corrugated pipe 4-3 has short straight pipes at both ends and a corrugated pipe in the middle. It is made of elastic brass and tin-plated on the outside.

[0032] The oil tank 8 has a through hole at the center of the upper end for connecting the lower end of the telescopic tube 4, and an external grounding wire made of brass with tin plating on the outside.

[0033] The thermistor 9 is a positive temperature coefficient thermistor.

[0034] like Figure 3 As shown, the input terminal of emergency stop switch 1 is connected to an external signal input terminal, the output terminal of emergency stop switch 1 is connected in series with the input terminal of thermistor 9, the output terminal of thermistor 9 is connected in series with the input terminal of primary coil 5, and the output terminal of primary coil 5 is connected to an external signal input terminal; the secondary coil 7 and the primary coil 5 are coaxial coils and are connected to an external signal output terminal.

[0035] During assembly, first press down the retractable elastic bellows 4-3, then hook the hooks at both ends of the tension spring 4-2 onto the two arc steel wires 4-1 at the two end holes respectively, and then release them. The elastic bellows 4-3 will spring back, stretching and pre-tightening the tension spring 4-2. With the correction of the two arc steel wires 4-1, the tension spring 4-2 will be aligned and centered. Then, attach the lower end of the telescopic tube 4 to the upper end through hole of the oil tank 8, braze and seal it, and then fill it with transformer oil containing 52# chlorinated paraffin. After the transformer oil is filled to the upper end hole of the telescopic tube 4, cover it with the top cover 3 and seal it. Then, attach the thermistor 9 to the side of the oil tank 8, and then connect the emergency stop switch 1 and the oil tank 8 with the support leg 2. Finally, connect the emergency stop switch 1, thermistor 9, and primary coil 5 in series with wires, and weld or ground the wire on the outside of the oil tank 8.

Claims

1. A safety-oriented, miniaturized oil-immersed high-frequency transformer, comprising: The system comprises an emergency stop switch, a support leg, a top cover, a telescopic tube, a primary coil, an iron core, a secondary coil, an oil tank, and a thermistor. The primary coil is sleeved on one side of the iron core, and the secondary coil is sleeved on the other side of the iron core. The primary coil, iron core, and secondary coil are all located inside the oil tank, and the thermistor is attached to the side of the oil tank. The system is characterized in that: the upper end of the oil tank has a through hole that connects to the lower end of the telescopic tube, and the upper end of the telescopic tube connects to the lower end of the top cover; the lower end of the support leg is connected to the outer edge of the upper end of the oil tank, and the upper end is connected to the outer edge of the lower side of the emergency stop switch.

2. The safety-type miniaturized oil-immersed high-frequency transformer according to claim 1, characterized in that: The emergency stop switch button is located at the bottom center.

3. A safety-type miniaturized oil-immersed high-frequency transformer according to claim 1 or 2, characterized in that: The telescopic tube includes: an arc-shaped steel wire, a tension spring, and an elastic corrugated tube; there are two arc-shaped steel wires, located at the upper and lower openings of the elastic corrugated tube respectively, with both ends of the arc-shaped steel wires fixedly connected to the openings, and the arc facing the inside of the elastic corrugated tube; the hooks at both ends of the tension spring are respectively suspended from the two arc-shaped steel wires.

4. A safety-type miniaturized oil-immersed high-frequency transformer according to claim 1, characterized in that: The emergency stop switch input terminal is connected to an external signal input terminal, the emergency stop switch output terminal is connected in series with the thermistor input terminal, the thermistor output terminal is connected in series with the primary coil input terminal, and the primary coil output terminal is connected to an external signal input terminal.

Images