Shunt tank system, liquid filling method and construction machine

Abstract

The invention relates to a shunt tank system (1) for a construction machine having a radiator (2) and a water pump (3) connected to an upper water chamber (201) and a lower water chamber (202) of the radiator (2). The system includes a shunt tank (102) and a filling tank (101), where the top of the shunt tank (102) is lower and the top of the filling tank (101) is higher than the upper water chamber (201). The filling tank (101) communicates with the radiator (2) through a first communication passage (11) and with the shunt tank (102) through a second communication passage (12) extending below a preset liquid level (L). The shunt tank (102) has a bottom connection port (102b) linked to the water pump (3). The invention also concerns a liquid filling method and a construction machine using this system.

Description

[0001]Description SHUNT TANK SYSTEM, LIQUID FILLING METHOD AND CONSTRUCTION MACHINE Technical Field The present invention relates to the technical field of heat dissipation, in particular to a shunt tank system for a construction machine, a liquid filling method for filling liquid by using the shunt tank system, and a construction machine comprising the shunt tank system. Background Art The shunt tank is an important part of the cooling system in a construction machine. As the cooling water in the cooling system heats up, the water pressure in the system increases. The shunt tank can accommodate the water expansion caused by thermal expansion, thus reducing the water pressure fluctuation caused by water expansion in the system and improving the safety and reliability of system operation. When the system leaks or cools down for some reason, the water level of the system will drop, and at this time it is necessary to replenish water for the system. The shunt tank can also be used as a water supply device to adjust the water volume of the system. In a closed cooling system, the shunt tank separates the air from the coolant and discharges the air to the outside to ensure normal operation of the cooling system. To ensure effective separation of gas and liquid, the shunt tank should be arranged at the highest place in the cabin and higher than the highest level of the cooling system, which makes components in the cabin hard to arrange compactly. As a result, it is difficult to improve the design and layout flexibility of the main peripheral components in the cabin. In addition, when it is necessary to replenish water to the cooling system or observe whether the coolant water level is in place, the workers have to climb to a high position, which greatly increases the difficulty of maintenance and repair. Therefore, it is an objective of the present invention to overcome one or more of the above problems. Summary of the Invention With regard to the above problems, the present invention proposes an improved shunt tank system, which enables the shunt tank to be arranged at any desired suitable position to facilitate subsequent liquid replenishment and liquid level observation. In addition, the system can ensure the safe and reliable operation of the cooling system. According to an aspect of the present invention, there is provided a shunt tank system for a construction machine. The construction machine comprises a radiator and a water pump in fluid connection with an upper water chamber and a lower water chamber of the radiator, wherein the shunt tank system comprises an shunt tank and a filling tank, a top of the shunt tank is lower than that of the upper water chamber of the radiator, a top of the filling tank is higher than that of the upper water chamber of the radiator, the filling tank is in fluid communication with the upper water chamber of the radiator through a first communication passage, and is in fluid communication with an interior of the shunt tank through a second communication passage, an upper port of the second communication passage is in communication with an interior of the filling tank in a top filling cap area of the filling tank, a lower port of the second communication passage extends into the interior of the shunt tank and is below a preset lowest liquid level of the shunt tank, and the shunt tank is provided with a connection port at its bottom, the connection port being in fluid connection with an input port of the water pump through a pipeline. Provided with a filling tank and a second communication passage, the shunt tank system according to the present invention advantageously solves the problem of limited space of the shunt tank, and ensures effective separation of gas and liquid in the whole system filling process and reliable operation of the cooling system. In an advantageous embodiment, the shunt tank is arranged outside the radiator; and / or the filling tank is integrated with the upper water chamber of the radiator. This provides much freedom for the design and layout of the radiator and the shunt tank. In an advantageous embodiment, the first communication passage comprises a liquid communication portion and a gas communication portion, which communicate with a bottom and an upper portion of an internal space of the filling tank, respectively. This configuration of the first communication passage makes the gas-liquid separation very effective. In an advantageous embodiment, a baffle is arranged in the shunt tank near the lower port of the second communication passage to prevent bubbles from entering the lower port of the second communication passage. In this way, it can be prevented that the gas reversely enters the second communication passage and the filling tank, causing insufficient gas-liquid separation which adversely affects the reliable operation of the water pump and the whole system. In an advantageous embodiment, a side of the shunt tank is provided with a sight gauge, which is marked with a lowest liquid level scale line and a highest liquid level scale line. In this way, the workers can observe the liquid level of the shunt tank at any time. In an advantageous embodiment, the lower port of the second communication passage is located at a position 5-10 mm below the preset lowest liquid level of the shunt tank. This liquid seal can ensure that no air will enter the second communication passage from its lower end port. According to another aspect of the present invention, there is provided a liquid filling method for filling liquid by using the above-mentioned shunt tank system. The liquid filling method comprises a first filling process, which comprises steps below: detaching a top filling cap fastened on a filling hole of the filling tank while keeping a top cap of the shunt tank buckled, and filling the filling tank with liquid via the filling hole; stopping filling the filling tank with liquid when the filling tank is full and a liquid level of the shunt tank reaches the preset lowest liquid level, and fastening the top filling cap onto the filling hole of the filling tank; detaching the top cap fastened on a filling port of the shunt tank, and filling the shunt tank with liquid via the filling port until the liquid level of the shunt tank reaches the preset highest liquid level; fastening the top cap to the filling port of the shunt tank, operating the water pump for a predetermined period of time, and then stopping the water pump; judging whether the liquid level of the shunt tank is at the preset highest liquid level, discharging excess liquid from the shunt tank when the liquid level is above the preset highest liquid level, and detaching the top cap of the shunt tank and filling the shunt tank with liquid via the filling port to the preset highest liquid level when the liquid level does not reach the preset highest liquid level, and then fastening the top cap to the filling port of the shunt tank. The liquid filling method can ensure that the coolant is fully distributed throughout the channels or flow paths of the system, avoiding air involvement and therefore cavitation against the water pump. In an advantageous embodiment, the liquid filling method comprises a liquid replenishing step of detaching the top cap of the shunt tank to fill the shunt tank with liquid via the filling port while keeping the top filling cap of the filling tank buckled. In this way, the workers do not need to climb up at the time of subsequent liquid replenishment, which will greatly enhance the convenience. According to still another aspect of the present invention, there is provided a construction machine. The construction machine comprises a radiator and a water pump in fluid connection with the radiator, characterized in that the construction machine further comprises the above-mentioned shunt tank system, wherein the filling tank of the shunt tank system is in fluid communication with the upper water chamber of the radiator, and the shunt tank of the shunt tank system is in fluid connection with the water pump. Advantageously, the construction machine comprises a motor to be cooled, which is arranged downstream of the water pump and upstream of the upper water chamber of the radiator, wherein the motor is positioned at a lower height than the upper water chamber of the radiator. Only further provided with a filling tank and first and second communication passages than the existing shunt tank, the shunt tank system according to the present invention features a simple structure and easy installation. Because it is not required that the shunt tank should be disposed at the highest point, the whole cooling system (including the radiator, fan, etc.) can have a more flexible and compact design and layout. In addition, the workers can replenish liquid, observe liquid level, or perform other operations required by the system easily and conveniently. The shunt tank system according to the present invention can also ensure the air to be discharged effectively out of the circulating coolant, thus improving the reliability and safety of the entire system operation. Brief Description of the Drawings Features and advantages of an example of the present invention will become apparent with reference to the following detailed description and drawings. Fig. 1 is a schematic diagram of a shunt tank system according to the present invention connected to a radiator; Fig. 2 is a schematic diagram of a filling tank of the shunt tank system according to the present invention; Fig. 3 is a schematic diagram of a shunt tank of the shunt tank system according to the present invention; and Fig. 4 is a schematic diagram of an internal structure of the shunt tank of the shunt tank system according to the present invention. List of Reference Signs 1-Shunt tank system; 101-Filling tank; 101p-Filling tank top cover; 101f-Filling hole; 101c-Top filling cap; W1-Liquid level observation window; 11-First communication passage; 111-Liquid communication portion; 112-Gas communication portion; 12-Second communication passage; 2-Radiator; 20-Radiator core; 201-Upper water chamber; 202-Lower water chamber; 102- Shunt tank; 102f-Filling port; 102c-Top cap; W2-Sight gauge; M-Highest liquid level scale line; L-Lowest liquid level scale line; 102o-Connection port; 102b- Baffle; 3-Water pump; 4-Motor. Detailed Description of the Embodiments In order that those skilled in the art can better understand the present invention, the technical solutions in the embodiments of the present invention will be described clearly and completely in conjunction with the accompanying drawings. Obviously, the described embodiments are only a part instead of the whole of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without exerting any creative effort should fall within the scope of protection of the present invention. It should be noted that the terms "comprising", “including” and "having" and any variation thereof in the description, claims, and accompanying drawings of the present invention are intended to mean non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the explicitly listed steps or units, but may include other steps or units not explicitly listed or inherent to the process, method, product or device. In the illustrated embodiment of the present invention, a radiator 2 vertically installed on a frame of a construction machine includes a radiator core 20, an upper water chamber 201 disposed above the radiator core, and a lower water chamber 202 disposed below the radiator core. The lower water chamber of the radiator is in fluid connection with an input port of a water pump 3 through a pipeline, an output port of the water pump is in fluid connection with a motor 4 to be cooled, and a liquid outlet of the motor is in fluid connection with the upper water chamber 201 of the radiator 2 through a pipeline. Thus, the radiator 2, the water pump 3 and the motor 4 form a closed coolant circulation loop. As shown in fig. 1, a shunt tank system 1 according to the present invention includes a filling tank 101 and a shunt tank 102. The filling tank 101 and the shunt tank 102 are arranged outside the radiator 2. The shunt tank 102 is in a lower position relative to the radiator 2. The filling tank 101 is in a higher position relative to the upper water chamber 201 of the radiator 2. The filling tank 101 is in fluid communication with the upper water chamber 201 of the radiator 2 through the first communication passage 11. In the illustrated embodiment, the first communication passage 11 includes a liquid communication portion 111 and a gas communication portion 112. The first port of the liquid communication portion 111 communicates with the bottom of the internal space of the filling tank 101, and the second port of the liquid communication portion 111 communicates with the upper water chamber 201 of the radiator 2. The first port of the gas communication portion 112 communicates with the upper part of the internal space of the filling tank. As can be seen from fig. 2, the first port of the gas communication portion 112 opens into the filling tank at a position P close to a top cover 101p of the filling tank. The second port of the gas communication portion 112 communicates with the top of internal space of the upper water chamber 201 of the radiator. In the embodiment shown in fig. 1, the second port of the gas communication portion 112 can be directly combined with the liquid communication portion 111 near the second port of the liquid communication portion 111 to form a bifurcation for gas-liquid separation. When the upper water chamber 201 of the radiator 2 is nearly full, the gas will enter the gas communication portion 112 at the bifurcation and flow to the upper part of internal space of the filling tank, and liquid will enter the liquid communication portion 111 and flow into the filling tank. This will avoid formation of bubbles due to gas-liquid mixing during liquid filling as much as possible. As shown in fig. 1, the filling tank 101 is in fluid communication with the interior of the shunt tank 102 through the second communication passage 12. With reference to fig. 2, the upper port of the second communication passage 12 communicates with the interior of the filling tank in an area S of a filling hole 101f of the filling tank 101. A top filling cap 101c is buckled on the filling hole 101f. For convenient observation of the liquid level in the filling tank, a side of the filling tank is provided with a liquid level observation window W1. As shown in figs. 3 and 4, a side of the shunt tank is provided with a sight gauge W2, which is marked with a lowest liquid level scale line L and a highest liquid level scale line M. The lower port of the second communication passage 12 extends into the interior of the shunt tank and is located below the preset lowest liquid level of the shunt tank. The preset lowest liquid level may correspond to the liquid level indicated by the lowest liquid level scale line L. In the illustrated embodiment, the lower port of the second communication passage 12 is located at a position 5-10 mm below the preset lowest liquid level of the shunt tank. As shown in figs. 1 and 4, the shunt tank 102 is provided at its bottom with a connection port 102o, which is in fluid connection with the input port of the water pump 3 through a pipeline. Referring to fig. 4, a baffle 102b is provided in the interior of the shunt tank 102 near the lower port of the second communication passage 12 to prevent air bubbles from entering the lower port of the second communication passage. The size of the baffle can be set as required, but shall not affect the fluid communication between a compartment where the lower port of the second communication passage 12 is located and an internal main chamber of the shunt tank 102. The shunt tank is provided at its top with a filling port 102f and a top cap 102c for closing the filling port. In the embodiment shown in fig. 4, the filling port 102f of the shunt tank 102 is set as far as possible away from the area where the lower port of the second communication passage 12 is located. In this way, the fluctuation influence on the lower port of the second communication passage will be minimized in the process of liquid filling or liquid replenishment. Next, the liquid filling process and operation principle using a shunt tank system will be described with reference to the whole coolant circulation loop shown in fig. 1 that is equipped with a shunt tank system of the present invention. Before ex-factory commercial sale, the coolant circulation loop shall go through a first filling process (an initial filling process). The first filling process comprises the steps below: Step 1: detaching the top filling cap fastened on the filling hole of the filling tank while keeping the top cap of the shunt tank buckled, and filling the filling tank with liquid via the filling hole. During step 1, it is necessary to ensure that the top cap of the shunt tank is closed, that is, the shunt tank is not in communication with the atmospheric pressure. At this time, the liquid will first flow into the lower water chamber of the radiator and the radiator core. When about 1 / 3 of the volume of the radiator is filled with liquid, the liquid will flow into the motor through a liquid outlet of the lower water chamber of the radiator. When about 1 / 2 of the volume of the radiator is filled with liquid, the motor is substantially fully filled, and the air in the motor is squeezed back to the upper water chamber of the radiator through a liquid inlet of the upper water chamber of the radiator. As liquid filling proceeds, the upper water chamber of the radiator and the first communication passage are filled with liquid. The air in the upper water chamber of the radiator enters the filling tank through the gas communication portion of the first communication passage during the liquid filling process. When the filling tank is fully filled, the air gathered in the filling tank has been discharged through the filling hole. In the process of liquid filling, the liquid will flow into the shunt tank through a three-way pipeline near an inlet of the water pump towards the connection port at the bottom of the shunt tank, and at the same time, some air will be squeezed into the shunt tank. Step 2: stopping filling the filling tank with liquid when the filling tank is full and the liquid level of the shunt tank reaches the preset lowest liquid level, and fastening the top filling cap to the filling hole of the filling tank. When the liquid level of the shunt tank reaches the preset lowest liquid level and the filling tank is fully filled, the gas in the shunt tank will occupy the space above the liquid level, forming a certain pressure. At this time, the lower port of the second communication passage is below the liquid level of the shunt tank. Almost all the air inside the filling tank is squeezed out. The closing of the top filling cap of the filling tank can ensure that the filling tank is fully filled with liquid (without gas); Step 3: detaching the top cap fastened on a filling port of the shunt tank, and filling the shunt tank with liquid via the filling port until the liquid level of the shunt tank reaches the preset highest liquid level. The preset highest liquid level can correspond to the liquid level indicated by the highest liquid level scale line of the sight gauge. During step 3, when the top cap of the shunt tank is detached for injection of liquid, because the lower port of the second communication passage is below the liquid level, a liquid seal is formed for the second communication passage to prevent gas from entering the interior of the second communication passage. This is conducive to gas-liquid separation, and can keep the liquid level of the second communication passage full of liquid and the liquid level of the filling tank unchanged; Step 4: fastening the top cap to the filling port of the shunt tank, operating the water pump for a predetermined period of time, and then stopping the water pump. The predetermined time period is greater than or equal to 5 minutes. The water pump is operated for driving away as much air as possible in some dead corners of the radiator, and making the liquid fill as much as possible of the whole coolant circulation loop. A tiny amount of squeezed air finally returns to the shunt tank and is discharged through an air release valve of the shunt tank. The inlet of the water pump is connected with the connection port at the bottom of the shunt tank, which increases the pressure at the inlet of the water pump and reduces the possibility of cavitation of the water pump. Step 5: judging whether the liquid level of the shunt tank is at the preset highest liquid level, discharging excess liquid from the shunt tank when the liquid level is above the preset highest liquid level, and detaching the top cap of the shunt tank and filling the shunt tank with liquid via the filling port to the preset highest liquid level when the liquid level does not reach the preset highest liquid level, and then fastening the top cap to the filling port of the shunt tank. The first to fifth steps are implemented in sequence. The end of the fifth step marks the end of the first filling process. At this time, optionally, the top filling cap of the filling tank can be welded onto the filling tank, keeping the filling tank permanently closed. After the whole machine is sold out, the liquid level of the shunt tank may drop during the operation of the machine due to the change of working conditions. At this point, the maintenance personnel can directly remove the top cap of the shunt tank and fill the shunt tank with liquid through the filling port for fluid replenishment. Because the shunt tank is in a lower position relative to the radiator, the maintenance personnel can replenish fluid and check the liquid level conveniently. In addition, it is unnecessary to place the shunt tank with after-sales filling function at the highest point of the coolant circulation loop (or radiator system) as in the prior art. Therefore, the position of the shunt tank is no more strictly restricted. Besides, in the shunt tank system of the present invention, the second communication passage is introduced and extends into a position below the lowest liquid level of the shunt tank, keeping the filling tank being filled with liquid almost all the time. Therefore, compared with the auxiliary water tank in the prior art, which is prone to negative pressure suction failure, the shunt tank system of the present invention is more reliable. Industrial Applicability The installation process and working principle of the shunt tank system according to the present invention are described below to help understand the present invention. First, install the radiator vertically on the frame of the machine. The upper water chamber of the radiator is connected with the liquid outlet of the motor through a hose, the lower water chamber of the radiator is connected with the input port of the water pump through a hose, and the output port of the water pump is connected with the liquid inlet of the motor, thereby a coolant circulation loop is formed. The filling tank is arranged at a higher position than the upper water chamber of the radiator. The shunt tank is arranged at a relatively low position next to the radiator. Then, connect the pipelines of the shunt tank system. The liquid communication between the filling tank and the upper water chamber of the radiator is achieved by using the liquid communication portion of the first communication passage, and the gas communication between the filling tank and the upper water chamber of the radiator is achieved by the gas communication portion of the first communication passage. The upper port of the second communication passage extends into the interior of the filling tank at the top filling cap area of the filling tank, and the lower port of the second communication passage extends into the interior of the shunt tank at a position 5- 10 mm below the lowest liquid level. Thereby, a fluid communication is achieved between the top of internal space of the filling tank and the space below the lowest liquid level inside the shunt tank. Implement the first filling process after the pipelines of the shunt tank system are connected: detach the top filling cap fastened on the filling hole of the filling tank, tighten the top cap on the filling port of the shunt tank, and fill the filling tank with coolant through the filling hole; when the filling tank is full and the liquid level in the shunt tank reaches the lowest liquid level scale line, tighten the top filling cap of the filling tank to close the filling hole; then, detach the top cap fastened on the filling port of the shunt tank, and fill the shunt tank with coolant through the filling port until the liquid level of the shunt tank reaches the highest liquid level scale line; fasten the top cap to the filling port of the shunt tank, keep the water pump running for more than 5 minutes, and then stop the water pump; check whether the liquid level in the shunt tank is at the highest liquid level scale line; if it exceeds the highest liquid level scale line, discharge excess liquid from the whole system; if it does not reach the highest liquid level scale line, detach the top cap of the shunt tank and fill the shunt tank with liquid through the filling port until it reaches the highest liquid level scale line, and then tighten the top cap of the shunt tank. Thus, the first filling process is completed. In the subsequent maintenance process, the top cap of the shunt tank can be directly unscrewed to replenish the shunt tank through the filling port of the shunt tank. This greatly facilitates the workers checking the liquid level or replenishing the liquid, and avoids the trouble of climbing up to check the liquid level of or to replenish liquid for the shunt tank at the highest point. In addition, it is not required that the shunt tank be placed at the highest point, but can be placed at any suitable height, which is conducive to flexible assembly and arrangement. The terms "first", "second", etc. introduced in the description of the shunt tank system are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance. The orientations or positional relationships indicated by the orientation words like "top", "bottom", "upper" and "lower" are based on the orientations or positional relationships shown in the accompanying drawings. In the embodiment shown in fig. 1, the radiator is shown to include two juxtaposed heat exchangers, and the upper water chamber, the radiator core and the lower water chamber of each heat exchanger are independent of each other. It will be appreciated that the specific configuration of the radiator can be changed according to the need. For example, the radiator is designed to include three or more juxtaposed heat exchangers, etc., and according to the specific configuration of the heat exchanger, the first communication passage can be designed to have a corresponding number of gas communication portions and liquid communication portions. The radiator can also be designed to have only one heat exchanger. The filling tank can also be integrated into the upper water chamber of the radiator. In this case, seen from the appearance, the protruding box on the top of the upper water chamber of the radiator is used as the filling tank, and the first communication passage constructed to communicate a main chamber of the upper water chamber with the filling tank can be formed of an internal contour of a housing of the upper water chamber. In this way, externally exposed communication pipelines can be omitted to simplify the pipeline layout of the system. In the embodiment shown in fig. 1, the shunt tank is installed on a side frame of the radiator. It will be appreciated that the shunt tank can also be set at other suitable locations, as long as it is lower than the upper water chamber of the radiator. "The shunt tank in a lower position relative to the radiator" here means that the top of the shunt tank is lower than the top of the radiator or lower than the top of the upper water chamber of the radiator. "The filling tank in a higher position relative to the upper water chamber of the radiator" means that the top of the filling tank is higher than the top of the upper water chamber of the radiator, that is, at least a part or the whole of the filling tank is located at a higher position than the top of the upper water chamber of the radiator. Although the first communication passage and the second communication passage are constructed as pipes / pipelines in the illustrated embodiment, it will be appreciated that the first communication passage (including the gas communication portion and the liquid communication portion) and the second communication passage can be designed as channels, through- slots or through-holes according to the specific layout. Exemplary embodiments of the shunt tank system according to the present invention are described hereinabove, but the method and device are not limited to the specific embodiments described herein. "An example", "another example", "examples", and the like mentioned throughout the specification are intended to describe that a certain member / element (such as feature, structure, and / or characteristic) associated with the example is included in at least one example described herein and may or may not appear in other examples. In addition, it will be appreciated that multiple elements in any example described herein may be combined in any suitable manner in multiple different examples, unless otherwise explicitly stated in the context. In the specification, the invention is disclosed by way of examples, including the optimal embodiment, which enables the skilled in the art to implement the present invention. The patentable scope of the present invention is defined by the claims, and may include other examples that may occur to those skilled in the art. If these other examples include structural elements that are not distinguishable from those described in the literal language of the claims, or if they include equivalent structural elements that are not substantially distinguishable from those described in the literal language of the claims, then they should fall within the scope of the claims.

Claims

Claims 1. A shunt tank system for a construction machine, the construction machine comprising a radiator and a water pump in fluid connection with an upper water chamber and a lower water chamber of the radiator, wherein the shunt tank system comprises an shunt tank and a filling tank, a top of the shunt tank is lower than a top of the upper water chamber of the radiator, a top of the filling tank is higher than a top of the upper water chamber of the radiator, the filling tank is in fluid communication with the upper water chamber of the radiator through a first communication passage, and is in fluid communication with an interior of the shunt tank through a second communication passage, an upper port of the second communication passage is in communication with an interior of the filling tank in a top filling cap area of the filling tank, a lower port of the second communication passage extends into the interior of the shunt tank and is below a preset lowest liquid level of the shunt tank, and the shunt tank is provided with a connection port at its bottom, the connection port being in fluid connection with an input port of the water pump through a pipeline.

2. The shunt tank system according to claim 1, characterized in that the shunt tank is arranged outside the radiator; and / or the filling tank is integrated with the upper water chamber of the radiator.

3. The shunt tank system according to claim 1 or 2, characterized in that the first communication passage comprises a liquid communication portion and a gas communication portion, which communicate with a bottom and an upper portion of an internal space of the filling tank, respectively.

4. The shunt tank system according to claim 1 or 2, characterized in that a baffle is arranged in the shunt tank near the lower port ofthe second communication passage to prevent bubbles from entering the lower port of the second communication passage.

5. The shunt tank system according to claim 1 or 2, characterized in that a side of the shunt tank is provided with a sight gauge, which is marked with a lowest liquid level scale line and a highest liquid level scale line.

6. The shunt tank system according to claim 1 or 2, characterized in that the lower port of the second communication passage is located at a position 5-10 mm below the preset lowest liquid level of the shunt tank.

7. A liquid filling method for filling liquid by using the shunt tank system according to any one of claims 1 to 6, comprising a first filling process, which comprises steps below: detaching a top filling cap fastened on a filling hole of the filling tank while keeping a top cap of the shunt tank buckled, and filling the filling tank with liquid via the filling hole; stopping filling the filling tank with liquid when the filling tank is full and a liquid level of the shunt tank reaches the preset lowest liquid level, and fastening the top filling cap to the filling hole of the filling tank; detaching the top cap fastened on a filling port of the shunt tank, and filling the shunt tank with liquid via the filling port until the liquid level of the shunt tank reaches the preset highest liquid level; fastening the top cap to the filling port of the shunt tank, operating the water pump for a predetermined period of time, and then stopping the water pump; judging whether the liquid level of the shunt tank is at the preset highest liquid level, discharging excess liquid from the shunt tank when the liquid level is above the preset highest liquid level, and detaching the top cap of theshunt tank and filling the shunt tank with liquid via the filling port to the preset highest liquid level when the liquid level does not reach the preset highest liquid level, and then fastening the top cap to the filling port of the shunt tank.

8. The liquid filling method according to claim 7, characterized by comprising a liquid replenishing step of detaching the top cap of the shunt tank to fill the shunt tank with liquid via the filling port while keeping the top filling cap of the filling tank buckled.

9. A construction machine, comprising a radiator and a water pump in fluid connection with the radiator, characterized in that the construction machine further comprises a shunt tank system according to any one of claims 1 to 6, wherein the filling tank of the shunt tank system is in fluid communication with the upper water chamber of the radiator, and the shunt tank of the shunt tank system is in fluid connection with the water pump.

10. The construction machine according to claim 9, characterized by comprising a motor to be cooled, which is arranged downstream of the water pump and upstream of the upper water chamber of the radiator, wherein the motor is positioned at a lower height than the upper water chamber of the radiator.

Images