Expansion water tank with locking function

Abstract

The utility model relates to the field of expansion water tank, concretely relates to an expansion water tank with locking function. Including box body and be used for sealing the filling cover of filling port on the box body, the filling cover has mistaken opening prevention locking structure, the mistaken opening prevention locking structure is configured as allowing the filling cover is locked in the filling port when rotating to locking direction, and produces idling when rotating to opening direction. The mistaken opening prevention locking structure is arranged on the filling cover of expansion water tank in the application, so that the filling cover can be stably locked to the filling port of the box body when rotating to the locking direction, and idling effect is produced when rotating to the opening direction, effectively preventing the misoperation of non-professionals, fundamentally avoiding the risk of personnel scalding caused by high-temperature cooling liquid or steam spraying due to the mistaken opening of the filling cover, and also preventing the damage of the thermal management system and associated equipment caused by the random filling of cooling liquid that does not meet the design requirements.

Description

Technical Field

[0001] This utility model relates to the field of expansion tanks, specifically to an expansion tank with a locking function. Background Technology

[0002] In the thermal management system of new energy commercial vehicles, the expansion tank is one of the core components for maintaining stable system operation. Its core function is to compensate for the volume fluctuations of coolant caused by temperature changes, ensuring that the system pressure remains within a safe range. When the water temperature in the thermal management system pipeline rises, the coolant expands due to thermal expansion and contraction, causing the system pressure to rise. At this time, the expansion tank can absorb the expanded coolant in time, avoiding the risk of pipeline rupture due to excessive internal pressure. When the coolant temperature drops, a negative pressure is formed inside the system, and the expansion tank will draw the stored coolant back into the system, ensuring the continuity of coolant circulation and thus maintaining the normal operation of the entire thermal management system. With the continuous development of new energy commercial vehicle technology, the working environment of the thermal management system is becoming increasingly complex, placing higher demands on the safety and reliability of the expansion tank. However, existing expansion tanks generally have a key deficiency: the filler cap lacks an effective protection mechanism against accidental opening. Because new energy commercial vehicles are used in diverse scenarios, the personnel involved include not only professional maintenance personnel but also non-professional users or related staff. These individuals often lack understanding of the working principle of the expansion tank and are not equipped with corresponding protective equipment. They may unknowingly unscrew the tank cap. The dangers of such misoperation are extremely serious: First, when the system is under high pressure, the high-temperature coolant or steam in the tank will spray out rapidly the moment the cap is unscrewed, easily causing severe burns to the operator and directly threatening personal safety. Second, non-professionals may add coolant that is inconsistent with the system's design requirements. Mixing different types of coolant will destroy the original coolant's chemical properties and performance, leading to corrosion, blockage, or damage to core components such as thermal management system pipes, water pumps, and radiators. It may even affect the normal operation of related equipment such as under-vehicle overcharge liquid cooling piles, resulting in high maintenance costs and potentially causing the vehicle to break down on the road, affecting operational efficiency. Summary of the Invention

[0003] The purpose of this utility model is to provide an expansion tank with a locking function to solve the problem of how to prevent non-professionals from accidentally unscrewing the expansion tank filling cap through structural design.

[0004] To achieve the above objectives, the following technical solution is adopted.

[0005] An expansion tank with a locking function includes a tank body and a filling cap for sealing the filling port on the tank body. The filling cap has an anti-accidental opening locking structure, which is configured to allow the filling cap to lock onto the filling port when rotated in the locking direction and to generate free rotation when rotated in the opening direction.

[0006] Optionally, the filling cap includes an outer cap and a middle cap for threaded connection with the filling port, and a one-way transmission mechanism is provided between the outer cap and the middle cap.

[0007] Optionally, the one-way transmission mechanism includes locking teeth disposed on the outer cover and / or the middle cover, and corresponding elastic buckles; when the outer cover rotates in the locking direction, the locking teeth push the elastic buckles to make the outer cover drive the middle cover to rotate synchronously; when the outer cover rotates in the opening direction, the locking teeth act on the elastic buckles to retract or make way, so that the outer cover rotates freely relative to the middle cover.

[0008] Optionally, the filling cap may further include an inner layer pressure relief device disposed inside the middle cap, the inner layer pressure relief device including a pressure regulating valve and a negative pressure compensation valve.

[0009] Optionally, the housing is provided with a liquid level sensor mounting port, and the axis of the liquid level sensor mounting port is arranged in a horizontal direction.

[0010] Optionally, it also includes a liquid level sensor, the connector of which is horizontally inserted into the liquid level sensor mounting port.

[0011] Optionally, the side wall of the housing is provided with a snap-fit ​​structure for fixing the degassing pipeline.

[0012] Optionally, the middle cover and the filling port are connected by a thread, and the outer cover is rotatably fitted onto the outside of the middle cover.

[0013] Optionally, the housing is also provided with a liquid replenishment port, a water outlet, and a degassing port.

[0014] Compared with the prior art, the present invention has the following beneficial effects: This application incorporates an anti-accidental opening locking structure on the expansion tank's filling cap. This ensures the cap is stably locked to the filling port when rotated in the tightening direction, while allowing free rotation when rotated in the opening direction. This effectively prevents accidental operation by unqualified personnel, fundamentally avoiding the risk of burns from hot coolant or steam erupting due to accidental opening of the filling cap. It also prevents damage to the thermal management system and related equipment caused by the arbitrarily added coolant that does not meet design requirements, significantly improving the safety and operational reliability of the expansion tank and the entire thermal management system. The unidirectional transmission design between the outer and middle caps ensures stable power transmission during locking, guaranteeing a secure lock. The free rotation function in the opening direction is achieved through the cooperation of locking teeth and elastic buckles. The structure is simple and reliable, ensuring both anti-accidental opening and allowing qualified personnel to perform compliant operations using specific methods. The inner pressure relief device on the inside of the filler cap can flexibly adjust pressure and compensate for negative pressure according to changes in system pressure. When the system pressure exceeds the set value, it releases excess pressure in time to prevent pipes from bursting due to overpressure. When the system develops negative pressure, it replenishes coolant in time to prevent water pump damage due to cavitation corrosion, further ensuring the pressure stability of the thermal management system. The liquid level sensor adopts a horizontal installation method, effectively avoiding the problem of water ingress or accumulation at the connector, enhancing the stability and service life of the sensor, and at the same time, it can monitor the coolant level in the tank in real time, providing accurate data for the system's replenishment and drainage control, ensuring that the liquid level is always within a reasonable range. The snap-fit ​​structure on the side wall of the tank can directly fix the degassing pipe, reducing the use of external supports, simplifying the installation process, optimizing the space layout, and reducing assembly costs. The rational configuration of the liquid inlet, water outlet, and degassing port on the tank works synergistically with the overall structure to ensure smooth flow of coolant within the system. Combined with the design of locking structure and pressure relief device, the overall performance of the expansion tank is comprehensively improved, providing a strong guarantee for the long-term stable operation of the thermal management system of new energy commercial vehicles. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of an expansion tank with locking function according to the present invention. Figure 2 This is a schematic diagram of an expansion tank assembly with locking function according to the present invention. Figure 3 This is a schematic diagram of the structure of an expansion tank with a locking function for adding a filling cover according to the present invention; Figure 4 This is a schematic diagram of the internal structure of an expansion tank filling cover with locking function according to the present invention; Figure 5 This is a schematic diagram of a one-way transmission mechanism for adding a cap to an expansion tank with a locking function, according to the present invention. The components include: 1. Tank body; 2. Filling cap; 21. Outer cover; 22. Middle cover; 23. Inner layer pressure relief device; 231. Pressure regulating valve; 232. Negative pressure compensation valve; 24. Locking teeth; 25. Elastic buckle; 3. Liquid level sensor; 4. Liquid level sensor mounting port; 5. Filling port; 6. Snap-fit ​​structure; 7. Liquid replenishment port; 8. Water outlet; 9. Degassing port. Detailed Implementation

[0016] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0017] The following detailed description is exemplary and intended to provide further detailed explanation of the present invention. Unless otherwise specified, all technical terms used in this invention have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. The terminology used in this invention is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to the present invention.

[0018] like Figures 1-5 As shown, this expansion tank is used in the thermal management system of new energy commercial vehicles. Its overall structure is optimized around the functions of preventing accidental opening, pressure regulation, liquid level control and installation adaptability to ensure stable and reliable operation under complex vehicle conditions.

[0019] The housing 1, serving as the load-bearing foundation of the entire device, is made of high-strength and corrosion-resistant composite materials. Commonly used composite materials include glass fiber reinforced nylon, carbon fiber reinforced resin matrix composites, etc. These materials possess excellent mechanical strength, impact resistance, and chemical stability, enabling them to withstand the high and low temperature cycles, vibration impacts, and chemical corrosion of coolant encountered during the operation of new energy commercial vehicles, making them suitable for the harsh environment of long-term vehicle operation. The external design of housing 1 fully integrates with the chassis space layout and thermal management system piping routing of different new energy commercial vehicles. It can be designed as a rectangular cylinder or an irregular irregular shape according to actual installation requirements, ensuring a tight fit to the vehicle's reserved installation position and minimizing space occupation. The interior of housing 1 is carefully designed with reasonable flow channels and buffer spaces. The flow channels adopt an arc-shaped transition structure to avoid right angles or sharp dead angles, reducing resistance during coolant flow and ensuring that the coolant can circulate quickly and smoothly inside and outside housing 1. The volume of the buffer space is scientifically set according to the total amount of coolant in the thermal management system, typically 10% to 15% of the total system coolant volume, which can fully absorb the volume expansion of coolant caused by temperature changes and avoid abnormal fluctuations in system pressure. The housing 1 integrates multiple functional interfaces, namely the filling port 5, the water inlet, the degassing port 9, and the liquid replenishment port 7. Each interface is integrally formed with the housing 1, and the inner wall of the interface is machined with a precision connection structure to ensure a firm and sealed connection with the corresponding pipeline of the thermal management system and prevent coolant leakage.

[0020] The filling cap 2, as a core functional component, mainly consists of three parts: an outer cap 21, a middle cap 22, and an inner pressure relief device 23. These three parts work together to achieve sealing, prevention of accidental opening, and pressure regulation. The outer cap 21 is made of engineering plastic, possessing good mechanical strength and wear resistance. Its surface is textured with anti-slip textures, which can be diamond, vertical, or cross-patterned. By increasing the friction between the hand and the surface of the outer cap 21, it facilitates gripping and applying force during assembly and professional maintenance, preventing slippage. The outer cap 21 is rotatably fitted onto the outside of the middle cap 22. The inner side of the outer cap 21 has an annular guide groove, and the outer side of the middle cap 22 has a corresponding annular guide boss. The guide boss is embedded in the guide groove, forming a sliding fit. This ensures both the relative rotational freedom between the outer cap 21 and the middle cap 22 and restricts their relative displacement in the axial direction, ensuring structural stability after assembly.

[0021] The middle cover 22 is made of engineering plastic with the same or similar performance as the outer cover 21. Its outer circumference is machined with precision threads that match the threads on the inner wall of the filling port 5 of the housing 1. Fine-pitch threads, such as M30×1.5, are typically used. Fine-pitch threads offer higher connection accuracy and sealing performance, effectively enhancing the tightness of the connection between the middle cover 22 and the filling port 5. A high-performance sealing ring is installed in the sealing groove of the middle cover 22. The sealing ring is made of fluororubber or silicone rubber, materials with excellent high-temperature resistance, corrosion resistance, and elasticity. It maintains good sealing performance within an operating temperature range of -40℃ to 120℃, preventing coolant leakage from the threaded connection and blocking external dust, moisture, and other impurities from entering the housing 1, thus avoiding coolant contamination and damage to system components.

[0022] The anti-accidental opening locking function is achieved through a one-way transmission mechanism located between the outer cover 21 and the middle cover 22. This one-way transmission mechanism consists of locking teeth 24 and elastic buckles 25, which work together to achieve power transmission in the locking direction and free rotation in the opening direction. The locking teeth 24 can be arranged in various ways: multiple locking teeth 24 can be evenly arranged circumferentially on the inner side of the outer cover 21, multiple locking teeth 24 can be evenly arranged circumferentially on the outer side of the middle cover 22, or mutually cooperating locking teeth 24 can be arranged on both the inner side of the outer cover 21 and the outer side of the middle cover 22. In practical applications, the most common arrangement is to arrange the locking teeth 24 on the inner side of the outer cover 21 and the elastic buckles 25 on the outer side of the middle cover 22. Each locking tooth 24 is designed as a wedge-shaped structure, with a vertical surface on the side facing the locking direction and an inclined surface on the side facing the opening direction. The vertical surface is used to transmit torque during locking, and the inclined surface is used to push the elastic buckles 25 to retract during opening. The elastic buckles 25 and locking teeth 24 can correspond one-to-one and are evenly arranged around the outer circumference of the middle cover 22. The elastic buckles 25 are made of spring steel or elastic plastic and have good elastic recovery ability. Each elastic buckle 25 is connected to a spring at the bottom. The diameter of the spring wire is 0.8 to 1.2 mm and the free length is 15 to 20 mm. After assembly, the spring is in a pre-compressed state with a pre-compression amount of 3 to 5 mm. The elastic force of the spring keeps the elastic buckle 25 in an outward extended state to ensure effective cooperation with the locking teeth 24.

[0023] When it is necessary to lock the filling cap 2, the operator rotates the outer cap 21 clockwise. The outer cap 21 drives the inner locking teeth 24 to rotate synchronously. The vertical surface of the locking teeth 24 makes rigid contact with the end of the elastic buckle 25, generating an axial thrust. This thrust overcomes the preload of the spring and drives the middle cap 22 to rotate synchronously. The middle cap 22 is gradually tightened to the filling port 5 through the precision thread until the applied torque reaches 3 to 5 N. At this point, the middle cover 22 and the filling port 5 achieve a tight seal, and the elastic buckle 25 is firmly engaged with the locking tooth 24 under the action of the spring, completing the locking operation. When someone attempts to rotate the outer cover 21 counterclockwise to open the filling cap 2, the inclined surface of the locking tooth 24 contacts the end of the elastic buckle 25. During the rotation, the inclined surface generates a radial force, which pushes the elastic buckle 25 inward to compress the spring at the bottom. At this time, the locking tooth 24 and the elastic buckle 25 form a relative sliding, and the rotational power of the outer cover 21 cannot be transmitted to the middle cover 22. The outer cover 21 only rotates freely around the middle cover 22, and the middle cover 22 remains locked, thus achieving the locking function to prevent accidental opening. When professionals need to open the filling cap 2 for maintenance, they can use a special tool to reach into the reserved operation hole of the outer cover 21, press the elastic buckle 25 to overcome the spring force and retract it inward, disengaging it from the engagement state with the locking tooth 24. At this time, rotating the outer cover 21 counterclockwise will drive the middle cover 22 to rotate synchronously, thus opening the filling cap 2.

[0024] The inner pressure relief device 23 is located inside the middle cover 22 and is fixed to the middle cover 22 by snap-fit ​​connection or threaded connection to ensure a firm connection and good sealing. It mainly consists of a pressure regulating valve 231 and a negative pressure compensation valve 232, which work together to achieve dynamic balance of system pressure. The pressure regulating valve 231, also known as a steam valve, has a core structure consisting of a valve core, a spring, and a valve seat. The valve core has a conical structure, and the valve core and valve seat are sealed by line contact. The sealing surface is precision polished to improve sealing reliability. The spring's preload is precisely calibrated to correspond to the system's set pressure threshold. During system operation, the coolant expands due to heat, causing the system pressure to rise. When the pressure reaches 100 kPa, the pressure on the valve core exceeds the spring's preload, pushing the valve core upward and opening the valve. Some of the high-temperature coolant and steam in the system flow into the housing 1 for temporary storage, while simultaneously separating the gas from the coolant during the flow. When the system pressure drops below 100 kPa, the spring's preload pushes the valve core back to its original position, closing the valve and preventing the coolant and gas from flowing in reverse, thus avoiding overpressure rupture of the system pipeline. The negative pressure compensation valve 232, also known as an air valve, has a similar structure to the pressure regulating valve 231, including a valve core, spring, and seat. The only difference is the spring preload setting. When the coolant temperature drops and the system contracts, a negative pressure is created inside. The external atmospheric pressure acts on the outside of the valve core, overcoming the spring preload and pushing the valve core open. At this time, the coolant inside the housing 1 is drawn into the system under siphon action, replenishing the insufficient coolant volume and maintaining a stable system level. This process effectively prevents damage to the water pump due to cavitation corrosion, ensuring the normal service life of the water pump. All components of the inner pressure relief device 23 are made of high-temperature and corrosion-resistant materials, such as stainless steel or high-temperature alloy for the valve core and seat, and heat-resistant spring steel for the spring, ensuring that they will not deform, corrode, or fail under long-term high-temperature and high-pressure working conditions.

[0025] A liquid level sensor mounting port 4 is provided on the housing 1. This mounting port is located on the lower side wall of the housing 1, with its axis arranged horizontally. This arrangement allows the connector of the liquid level sensor 3 to be inserted horizontally into the mounting port, preventing rainwater and condensation from accumulating at the connector if the connector is facing upwards or downwards. This significantly increases the waterproof safety of the connector and prevents short circuits or damage to the sensor due to water ingress or accumulation. The liquid level sensor 3 adopts a structural design adapted to the mounting port. Its detection end extends into the interior of the housing 1, allowing direct contact with the coolant or non-contact detection of liquid level changes. Common sensor types include float-type and capacitive sensors. The sensor's detection range covers the entire effective volume of the housing 1, achieving accurate detection from the lowest to the highest liquid level. The sensor's connector uses a waterproof joint design with a sealing ring. When connected to the mounting port, a threaded connection or interference fit is used to achieve a secure seal, ensuring a firm installation and reliable waterproof performance. The sensor is electrically connected to the vehicle's control system, enabling it to transmit the detected liquid level data to the control system in real time. When the liquid level is below 20%, the control system receives the signal and activates the external adjustment device to replenish coolant into the tank 1 through the replenishment port 7 until the liquid level returns to a reasonable range. When the liquid level is above 80%, the control system activates the external adjustment device to discharge excess coolant through the outlet 8, preventing abnormal system pressure caused by excessive liquid level. Through this dynamic control method, the liquid level inside the tank 1 is always kept within a reasonable range of 10% to 90%, ensuring the stable operation of the thermal management system.

[0026] The side wall of the housing 1 is integrally formed with a snap-fit ​​structure 6 for fixing the degassing pipe. The number of snap-fit ​​structures 6 is determined according to the length and layout requirements of the degassing pipe, usually 2 to 4, and evenly distributed along the extension direction of the degassing port 9. The snap-fit ​​structure 6 is made of the same composite material as the housing 1 to ensure that the structural strength is consistent with the housing 1 and can withstand the weight of the degassing pipe and the vibration load during vehicle operation. The snap-fit ​​is designed in a semi-circular shape with the opening facing outward. The opening width is slightly smaller than the outer diameter of the degassing pipe. This design allows the degassing pipe to be snapped into the snap-fit ​​through elastic deformation at the opening. The inner side of the snap-fit ​​is processed with anti-slip texture to increase the friction with the surface of the degassing pipe and achieve a tight clamping of the degassing pipe. When the degassing pipe is connected to the degassing port 9 of the housing 1, it is directly fixed to the side wall of the housing 1 by the snap-fit ​​structure 6. There is no need to set up external brackets and bolts or other fasteners. This not only simplifies the installation process of the pipe and reduces the assembly cost, but also reduces the number of parts and reduces the risk of pipe vibration and leakage caused by loose parts. At the same time, it makes the pipe layout more compact and orderly, which is suitable for the complex space environment inside the vehicle.

[0027] The coolant inlet 7 on the housing 1 is located on the upper side wall and is connected to an external coolant supply device via a pipeline. Inside the inlet 7 is a one-way valve with a valve core made of elastic material, allowing only external coolant to flow into the housing 1, preventing backflow of coolant inside the housing 1 due to system pressure fluctuations. The outlet 8 is located on the lower side wall of the housing 1 and is connected to the return pipeline of the thermal management system. Inside the outlet 8 is a filter with a mesh size of 50 to 100 microns, effectively filtering impurities in the coolant and preventing them from entering the system and damaging core components such as the water pump and radiator. The filter features a detachable design for easy periodic disassembly, cleaning, or replacement, ensuring long-term stable filtration performance. The degassing port 9 is located at the top of the housing 1, above the highest liquid level line of the housing 1, to ensure that the gas generated in the system can rise naturally to the degassing port 9 and be discharged, avoiding the accumulation of gas in the housing 1 to form air blockage, which would affect the circulation of coolant and the stability of system pressure. The inner wall of the degassing port 9 is machined with connecting threads, and it is connected to the degassing pipeline through threads. A sealing ring is provided at the connection to enhance the sealing performance.

[0028] The entire assembly process of the expansion tank is carried out strictly according to precise process steps. First, the connector of the liquid level sensor 3 is horizontally inserted into the installation port and fixed by threads or interference fit to ensure good sealing of the connector and no risk of water ingress. Then, the various components of the inner pressure relief device 23 are assembled and fixed to the inside of the middle cover 22 by snaps or threads, and the flexibility of valve opening and closing is checked. Next, the high-performance sealing ring is embedded into the sealing groove of the middle cover 22, ensuring that the sealing ring fits the groove wall completely without twisting or deformation. Then, the middle cover 22 is aligned with the filling port 5 of the tank body 1 and manually rotated to make the threads engage initially, ensuring that the middle cover 22 is installed in place. Then, the outer cover 21 is inserted into the outside of the middle cover 22 from above, so that the guide groove on the inside of the outer cover 21 engages with the guide boss on the outside of the middle cover 22, ensuring that the locking teeth 24 and the elastic buckles 25 are engaged one-to-one. Finally, the operator uses a torque wrench to rotate the outer cover 21 clockwise, applying 3 to 5 N. The torque of m locks the middle cover 22 and the filling port 5. At this time, the elastic buckle 25 is tightly engaged with the locking tooth 24 under the action of the spring, completing the assembly of the entire expansion tank.

[0029] In actual use, the expansion tank and the thermal management system pipeline of the new energy commercial vehicle are fully connected through various interfaces to form a closed-loop circulation system. When the vehicle is running, the thermal management system is activated, and the coolant circulates in the pipeline. As the system load increases, the coolant temperature gradually rises and expands, and the internal pressure of the system rises accordingly. When the pressure reaches 100 kPa, the pressure regulating valve 231 of the inner pressure relief device 23 automatically opens, introducing some high-temperature steam and coolant into the tank 1. The buffer space of the tank 1 absorbs the expansion, and the system pressure gradually decreases. When the pressure drops below the set threshold, the pressure regulating valve 231 closes under the action of the spring. When the system load decreases, the coolant temperature drops and contracts, and a negative pressure is formed inside the system. At this time, the negative pressure compensation valve 232 automatically opens, and a pressure difference is formed between the external atmospheric pressure and the system negative pressure. Under the siphon effect, the coolant stored inside the tank 1 is drawn into the system pipeline to replenish the insufficient coolant volume and maintain the stability of the system liquid level. The liquid level sensor 3 monitors the coolant level inside the housing 1 in real time and continuously transmits the liquid level data to the vehicle control system. When the liquid level is detected to be below 20%, the control system issues a liquid replenishment command, and the external liquid replenishment equipment is activated to replenish the housing 1 with the required amount of coolant through the liquid replenishment port 7 until the liquid level reaches a reasonable range. When the liquid level is detected to be above 80%, the control system issues a liquid drain command, and the external regulating equipment is activated to drain the excess coolant through the outlet 8 to ensure that the liquid level is always within a safe range. During daily use, if a non-professional attempts to accidentally open the filling cap 2, when the outer cover 21 is rotated counterclockwise, the locking teeth 24 contact the inclined surface of the elastic buckle 25, the elastic buckle 25 retracts, and the outer cover 21 only rotates freely, unable to drive the middle cover 22 to rotate, effectively preventing accidental opening. When professional maintenance personnel need to perform maintenance, such as changing the coolant and inspecting the inside of the tank 1, a special tool can be inserted into the reserved operation hole of the outer cover 21, and the elastic buckle 25 can be pressed to disengage it from the constraint of the locking teeth 24. At this time, rotating the outer cover 21 counterclockwise will drive the middle cover 22 to rotate synchronously. The middle cover 22 can be unscrewed from the filling port 5, and the filling cap 2 can be opened for relevant maintenance operations. After maintenance is completed, the filling cap 2 should be re-locked according to the assembly steps to ensure that the locking function is restored normally.

[0030] The overall design of this expansion tank fully considers the actual needs of the thermal management system for new energy commercial vehicles. Through a scientific and reasonable structural layout and functional design, it achieves multiple functions such as preventing accidental opening, pressure regulation, liquid level control, leakage prevention, and waterproofing. The various components work together, which not only effectively solves the risk of accidental opening that exists in traditional expansion tanks, but also significantly improves the safety, reliability, and ease of maintenance of the system. It can adapt to the complex operating conditions of new energy commercial vehicles for a long time and provides a strong guarantee for the stable and efficient operation of the thermal management system.

[0031] As is known from common technical knowledge, this utility model can be implemented through other embodiments that do not depart from its spirit or essential characteristics. Therefore, the above-disclosed embodiments are merely illustrative in all respects and are not the only ones. All modifications within the scope of this utility model or its equivalents are included in this utility model.

Claims

1. An expansion tank with a locking function, comprising a tank body (1) and a filling cap (2) for sealing the filling port (5) on the tank body (1), characterized in that, The filling cap (2) has an anti-misoperation locking structure, which is configured to allow the filling cap (2) to lock onto the filling port (5) when rotated in the locking direction and to generate free rotation when rotated in the opening direction.

2. An expansion tank with locking function according to claim 1, characterized in that, The filling cap (2) includes an outer cap (21) and a middle cap (22) for threaded connection with the filling port (5), and a one-way transmission mechanism is provided between the outer cap (21) and the middle cap (22).

3. An expansion tank with locking function according to claim 2, characterized in that, The one-way transmission mechanism includes locking teeth (24) disposed on the outer cover (21) and / or the middle cover (22), and corresponding elastic buckles (25); when the outer cover (21) rotates in the locking direction, the locking teeth (24) push the elastic buckles (25) to make the outer cover (21) drive the middle cover (22) to rotate synchronously; when the outer cover (21) rotates in the opening direction, the locking teeth (24) act on the elastic buckles (25) to retract or make way, so that the outer cover (21) rotates freely relative to the middle cover (22).

4. An expansion tank with locking function according to claim 2, characterized in that, The filling cap (2) also includes an inner layer pressure relief device (23) disposed inside the middle cap (22), the inner layer pressure relief device (23) including a pressure regulating valve (231) and a negative pressure compensation valve (232).

5. An expansion tank with locking function according to claim 1, characterized in that, The housing (1) is provided with a liquid level sensor mounting port (4), and the axis of the liquid level sensor mounting port (4) is arranged in a horizontal direction.

6. An expansion tank with locking function according to claim 5, characterized in that, It also includes a liquid level sensor (3), the connector of which is horizontally inserted into the liquid level sensor mounting port (4).

7. An expansion tank with locking function according to claim 1, characterized in that, The side wall of the housing (1) is provided with a snap-fit ​​structure (6) for fixing the degassing pipeline.

8. An expansion tank with locking function according to claim 2, characterized in that, The middle cover (22) is connected to the filling port (5) by a thread, and the outer cover (21) is rotatably fitted onto the outside of the middle cover (22).

9. An expansion tank with locking function according to claim 1, characterized in that, The box (1) is also provided with a liquid replenishment port (7), a water outlet (8) and a degassing port (9).

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