Engineering vehicle fuel tank system, engineering vehicle, and automatic oil sampling method

Abstract

The present invention discloses an engineering vehicle fuel tank system, an engineering vehicle, and an automatic oil sampling method, relating to the field of engineering vehicles and used to achieve automatic oil sample retention. The engineering vehicle fuel tank system includes a first fuel tank, a second fuel tank, a first oil return flow path, and a second oil return flow path. The first fuel tank is configured to store oil. The second fuel tank is also configured to store oil, and the volume of the second fuel tank is smaller than that of the first fuel tank. The first oil return flow path is in fluid communication with the first fuel tank. The second oil return flow path is in fluid communication with the second fuel tank. Among them, the oil return sequence of the first oil return flow path and the second oil return flow path is controllable. In the above technical solution, there are both a first fuel tank and a second fuel tank, and both fuel tanks receive the oil return of the fuel system. Moreover, the oil return pressure of the first fuel tank is greater than that of the second fuel tank. Therefore, in the case of needing to sample, the oil return can preferentially enter the second fuel tank to achieve smooth sampling.

Description

Technical Field

[0001] The present invention relates to the field of construction vehicles, and particularly to a fuel tank system for a construction vehicle, a construction vehicle, and an automatic sampling method. Background Art

[0002] The oil fluid of a construction vehicle is generally diesel. With the continuous improvement of national standards, whether the exhaust gas emitted by a construction vehicle meets the standards is an important criterion for inspecting whether the construction vehicle meets the national standard requirements. The components of the exhaust gas emitted by a construction vehicle are related to the performance of the vehicle itself on the one hand, and are also directly related to the quality of the diesel added by the user to the construction vehicle on the other hand.

[0003] When the exhaust gas emitted by a construction vehicle does not meet the standards, it is necessary to determine whether there is a malfunction in the construction vehicle itself or whether the diesel quality fails to meet the requirements.

[0004] The inventor found that there are at least the following problems in the prior art: Diesel is a consumable and is replaced frequently, so it is difficult to collect the oil fluid sample used at the time of a malfunction because it is impossible to determine whether the oil fluid quality meets the requirements. Summary of the Invention

[0005] The present invention provides a fuel tank system for a construction vehicle, a construction vehicle, and an automatic sampling method for an oil fluid to achieve automatic retention of the oil fluid sample.

[0006] An embodiment of the present invention provides a fuel tank system for a construction vehicle, including:

[0007] A first fuel tank configured to store an oil fluid;

[0008] A second fuel tank also configured to store an oil fluid, and the volume of the second fuel tank is smaller than the volume of the first fuel tank;

[0009] A first oil return flow path fluidly connected to the first fuel tank; and

[0010] A second oil return flow path fluidly connected to the second fuel tank;

[0011] wherein the oil return sequence of the first oil return flow path and the second oil return flow path is controllable.

[0012] In some embodiments, the oil return pressure of the first oil return flow path is greater than or equal to the oil return pressure of the second oil return flow path.

[0013] In some embodiments, the fuel tank system for a construction vehicle further includes:

[0014] A switching valve disposed in the second oil return flow path, the switching valve being configured to switch valve positions to switch the second oil return flow path between a conducting state and a disconnected state; and

[0015] A controller, electrically connected to the switching valve, is configured to control the valve position of the switching valve according to the operating signal of the engine of the construction vehicle, and to conduct the second oil return flow path when the engine is in an abnormal condition.

[0016] In some embodiments, the fuel tank system of the construction vehicle further includes:

[0017] A liquid level switch, disposed at the top of the second fuel tank, is electrically connected to the controller; the controller is further configured to disconnect the second oil return flow path when the liquid level of the second fuel tank detected by the liquid level switch is higher than a set value.

[0018] In some embodiments, the fuel tank system of the construction vehicle further includes:

[0019] A liquid level sensor, disposed in the first fuel tank, is configured to detect the oil level of the first fuel tank.

[0020] In some embodiments, the fuel tank system of the construction vehicle further includes:

[0021] A breather, a through hole is provided in the top cover of the second fuel tank, the breather is installed in the through hole or the breather covers the through hole, and the breather is configured to communicate the second fuel tank with the outside.

[0022] In some embodiments, the fuel tank system of the construction vehicle further includes:

[0023] A protective cover, the breather is located outside the second fuel tank, and the protective cover is located outside the breather.

[0024] In some embodiments, the first fuel tank and the second fuel tank are configured to be independent and not fluidly connected to each other.

[0025] In some embodiments, the installation position of the second oil return flow path is higher than the installation position of the first oil return flow path.

[0026] In some embodiments, the first oil return flow path includes:

[0027] A first pipeline, located outside the first fuel tank; and

[0028] A second pipeline, one end of which extends out of the first fuel tank and is fluidly connected to the first pipeline, and the other end extends into the bottom of the first fuel tank.

[0029] In some embodiments, the other end of the second pipeline is configured to be bent towards the top of the first fuel tank.

[0030] In some embodiments, the fuel tank system of the construction vehicle further includes:

[0031] A bracket, fixed to the inner wall of the first fuel tank, and the second pipeline is fixed by the bracket.

[0032] In some embodiments, the second fuel tank is located inside the first fuel tank and at the top of the first fuel tank; alternatively, the second fuel tank is located outside the first fuel tank.

[0033] In some embodiments, the engineering vehicle fuel tank system further includes:

[0034] A sampling joint, installed in the second oil return flow path, and the sampling joint is configured to communicate with a sampling pipeline to sample the oil in the second fuel tank.

[0035] An embodiment of the present invention further provides an engineering vehicle, including:

[0036] An engine, having an oil return branch; and

[0037] The engineering vehicle fuel tank system provided by any technical solution of the present invention; both the first oil return flow path and the second oil return flow path are in fluid communication with the oil return branch.

[0038] An embodiment of the present invention further provides a method for automatically sampling the oil of an engineering vehicle, implemented by using the engineering vehicle fuel tank system provided by any technical solution of the present invention, and the method includes the following steps:

[0039] Judge whether the engine control component of the engineering vehicle where the engineering vehicle fuel tank system is located emits an abnormal signal;

[0040] If the engine control component emits an abnormal signal, then conduct the second oil return flow path;

[0041] A part of the oil return of the engine flows to the second fuel tank via the second oil return flow path, and another part flows to the first fuel tank via the first oil return flow path.

[0042] In some embodiments, the step of if the engine control component emits an abnormal signal, then conduct the second oil return flow path specifically includes the following steps:

[0043] If the engine control component emits an abnormal signal, then judge whether the liquid level of the first fuel tank is higher than the opening set value and whether the liquid level of the second fuel tank is lower than the oil filling lower limit value;

[0044] If the liquid level of the first fuel tank is higher than the opening set value and the liquid level of the second fuel tank is lower than the oil filling lower limit value, then conduct the second oil return flow path.

[0045] In some embodiments, the automatic oil sampling method for engineering vehicles further includes the following steps: when the oil in the second fuel tank detected by the liquid level switch reaches a set value, the second oil return flow path is disconnected.

[0046] The engineering vehicle fuel tank system provided by the above technical solution has both a first fuel tank and a second fuel tank. Both fuel tanks receive the oil return from the fuel system, and the oil return pressure of the first fuel tank is greater than that of the second fuel tank. Therefore, in the case of needing to sample, the oil return can preferentially enter the second fuel tank to achieve smooth sampling. Description of the Drawings

[0047] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0048] Figure 1 It is a schematic diagram of the principle of the engineering vehicle fuel tank system provided by some embodiments of the present invention.

[0049] Figure 2 It is a front view direction schematic diagram of the second pipeline of the engineering vehicle fuel tank system provided by some embodiments of the present invention being fixed.

[0050] Figure 3 It is a top view direction schematic diagram of the second pipeline of the engineering vehicle fuel tank system provided by some embodiments of the present invention being fixed.

[0051] Figure 4 It is a schematic diagram of the principle of the engineering vehicle fuel tank system provided by some other embodiments of the present invention.

[0052] Figure 5 It is a schematic diagram of the flow of the automatic oil sampling method for engineering vehicles provided by some other embodiments of the present invention.

[0053] Figure 6 It is a schematic diagram of the control logic of the automatic oil sampling method for engineering vehicles provided by some other embodiments of the present invention.

[0054] Reference Numerals:

[0055] 1, First fuel tank; 2, Second fuel tank; 3, First oil return flow path; 4, Second oil return flow path; 5, Switching valve; 6, Controller; 7, Liquid level switch; 8, Liquid level sensor; 9, Breather; 10, Protective cover; 11, Bracket; 12, Sampling joint; 13, Bolt; 14, Mounting seat; 21, Through hole; 31, First pipeline; 32, Second pipeline. Detailed Embodiments

[0056] The following Figures 1 to 6 further elaborates on the technical solution provided by the present invention.

[0057] The inventors found that when a construction vehicle breaks down and it is necessary to collect the oil during the occurrence of the fault, the following factors may cause abnormal sampling during fault repair. For example, during repair, the oil in the first fuel tank is deliberately or accidentally emptied by humans, or new oil is added to the first fuel tank, or all the oil in the first fuel tank is consumed. The technical solution provided by the embodiments of the present invention can achieve normal sampling of the oil under any of the above circumstances to retain the sample oil.

[0058] See Figure 1 , the embodiments of the present invention provide a fuel tank system for a construction vehicle, including a first fuel tank 1, a second fuel tank 2, a first oil return flow path 3, and a second oil return flow path 4. The first fuel tank 1 is configured to store oil. The second fuel tank 2 is also configured to store oil, and the volume of the second fuel tank 2 is smaller than the volume of the first fuel tank 1. The first oil return flow path 3 is in fluid communication with the first fuel tank 1. The second oil return flow path 4 is in fluid communication with the second fuel tank 2. Among them, the pressure of the first oil return flow path 3 is greater than or equal to the pressure of the second oil return flow path 4. In some embodiments, the pressure of the first oil return flow path 3 is greater than the pressure of the second oil return flow path 4, so that the returned oil first enters the second oil return flow path 4, thereby preferentially ensuring that the amount of the retained sample oil is sufficient.

[0059] There are many ways to adjust the oil return pressure of the first oil return flow path 3 and the oil return pressure of the second oil return flow path 4: for example, by changing the respective structures of the first oil return flow path 3 and the second oil return flow path 4 to adjust the oil return pressure. In some embodiments, one end of the first oil return flow path 3 is located outside the first fuel tank 1, and the other end extends into the bottom of the first fuel tank 1. Since the first fuel tank 1 rarely becomes completely empty during the use of the construction vehicle, there is always some oil in the first fuel tank 1, and the oil stored in the first fuel tank 1 makes the oil return pressure via the first oil return flow path 3 increase. There is almost no oil return pressure in the second oil return flow path 4, which also causes a part of the returned oil to preferentially enter the second fuel tank 2 via the second oil return flow path 4; the rest returns via the first oil return flow path 3 and then enters the first fuel tank 1.

[0060] Optionally, pressure valves are provided in the first oil return flow path 3 and the second oil return flow path 4 to adjust their respective oil return pressures.

[0061] In some embodiments, the first fuel tank 1 is set at a lower position and the second fuel tank 2 is set at a higher position, so that the position of the first oil return flow path 3 is lower than the position of the second oil return flow path 4. Although their positions are different in height, it does not affect their relative relationship. Since the oil return pressure of the second oil return flow path 4 is less than the oil return pressure of the first oil return flow path 3, a part of the returned oil still enters the second fuel tank 2. See Figure 1As shown, the return oil S is divided into two branches S1 and S2. The branch S1 enters the first fuel tank 1, and the oil in the branch S2 enters the second fuel tank 2. The return oil pressure of the branch S1 is greater than that of the branch S2.

[0062] On the premise of no contradiction, the above various methods can be combined and used.

[0063] The first return oil flow path 3 and the second return oil flow path 4 jointly receive the return oil of the fuel system of the entire construction vehicle. The first fuel tank 1 has a large volume, and most of the return oil enters the first fuel tank 1. The second fuel tank 2 has a small volume, and a small part of the return oil enters the second fuel tank 2.

[0064] See Figure 1 , the first fuel tank 1 is the fuel tank of the construction vehicle, and its volume is related to the model and parameters of the vehicle. The second fuel tank 2 is used to store oil samples when necessary. The volume of the second fuel tank 2 is 2L to 20L, and the oil of this volume can complete the detection of the oil quality, so as to judge whether the quality of the oil meets the requirements. The second fuel tank 2 is located inside the first fuel tank 1 and at the top of the first fuel tank 1.

[0065] In some embodiments, the fuel tank system of the construction vehicle further includes a switching valve 5 and a controller 6. The switching valve 5 is arranged in the second return oil flow path 4, and the switching valve 5 is configured to switch the valve position so that the second return oil flow path 4 switches between the conducting state and the disconnecting state. The controller 6 is electrically connected to the switching valve 5, and the controller 6 is configured to control the valve position of the switching valve 5 according to the operation signal of the engine of the construction vehicle, and conduct the second return oil flow path 4 when the engine control component issues an abnormal signal. The engine control component is, for example, a controller such as a VCU.

[0066] The states of the first oil return flow path 3 and the second oil return flow path 4 are independent. The first oil return flow path 3 is always in a conducting state, and the on-off state of the second oil return flow path 4 can be adjusted. When a fault occurs in the engine of the construction vehicle, it is necessary to retain the oil return of the fuel system in the second fuel tank 2 at this time, so as to facilitate the subsequent detection of the quality of the oil fluid. The function of the controller 6 is to control the valve position of the switching valve 5 when a fault occurs in the engine, so that the second oil return flow path 4 is conducted. At this time, the oil return is divided into two streams. Most of it enters the first oil return flow path 3; a small part is diverted to flow to the second fuel tank 2 via the second oil return flow path 4 because after the second oil return flow path 4 is conducted, the oil return pressure of the second oil return flow path 4 is less than the oil return pressure of the first oil return flow path 3. It can be seen that the above-mentioned oil sampling process is realized during the normal oil return operation of the construction vehicle, without the need to set a separate sampling step and without any additional operations on the vehicle. Therefore, the vehicle user does not need to pay extra attention to the sampling operation. Moreover, the oil fluid obtained by the sampling operation is the oil return of the construction vehicle, which also reduces the problem of oil sample quality confusion caused by the user adding new oil fluid to the construction vehicle, and also reduces the loss of the oil fluid in the first fuel tank 1 caused by the damage or abnormality of the first fuel tank 1, thereby preventing the situation where oil sampling cannot be carried out subsequently. The above technical solution provides convenience for the subsequent smooth completion of oil sample detection by injecting sufficient oil fluid into the second fuel tank 2 during the oil return process.

[0067] The controller 6 determines when to conduct the second oil return flow path 4 according to the working state of the engine. As for how to disconnect the second oil return flow path 4, the following method can be used for judgment: In some embodiments, the fuel tank system of the construction vehicle further includes a liquid level switch 7. The liquid level switch 7 is arranged at the top of the second fuel tank 2. The liquid level switch 7 is electrically connected to the control; the controller 6 is further configured to disconnect the first oil return flow path 3 when the liquid level of the second fuel tank 2 detected by the liquid level switch 7 is higher than the oil filling upper limit value.

[0068] The oil filling upper limit value of the liquid level of the second fuel tank 2 is, for example, the liquid level corresponding to 70% - 90% of the volume of the second fuel tank 2. When the liquid level of the second fuel tank 2 is higher than the set value, it indicates that the amount of oil fluid in the second fuel tank 2 is sufficient for oil sample quality detection. At this time, the second fuel tank 2 does not need to receive oil fluid, and the oil return of the fuel system of the construction vehicle can all enter the first fuel tank 1 via the first oil return flow path 3.

[0069] Furthermore, in each embodiment having the liquid level switch 7, parameters for controlling the opening of the second oil return flow path 4 can also be increased according to the liquid level of the second fuel tank 2 detected by the liquid level switch 7. That is, when both conditions that the liquid level of the second fuel tank 2 detected by the liquid level switch 7 is lower than the oil filling lower limit value and the engine has an abnormality are satisfied, the controller 6 opens the switching valve 5 to conduct the second oil return flow path 4.

[0070] See Figure 1, in some embodiments, the fuel tank system of the construction vehicle further includes a sampling joint 12, and the sampling joint 12 is installed in the second oil return flow path 4. The sampling joint 12 is configured to communicate with a sampling pipeline (not shown in the figure) to sample the oil in the second fuel tank 2. The sampling joint 12 adopts a quick-connect joint, such as the male head of the quick-connect joint. The male head is in a cut-off state under normal conditions, and the oil in the second fuel tank 2 cannot be discharged through the male head. When it is necessary to take out the oil in the second fuel tank 2, the female head of the quick-connect joint is inserted into the male head. After the two are inserted, the male head and the female head are automatically conducted, and the oil in the second fuel tank 2 flows out of the second fuel tank 2 through the male head and the female head. The above technical solution realizes multiple consecutive samplings and can be reused after taking the oil.

[0071] See Figure 1 , the end of the second oil return flow path 4 that is fluidly connected to the second fuel tank 2 is located at the top or upper part of the second fuel tank 2, so that the oil in the second oil return flow path 4 can smoothly enter the second fuel tank 2 under the action of its own gravity.

[0072] Continue to see Figure 1 , in some embodiments, the fuel tank system of the construction vehicle further includes a breather 9. There is a through hole 21 in the top cover of the second fuel tank 2, and the breather 9 is installed in the through hole 21 or the breather 9 covers the through hole 21, and the breather 9 makes the second fuel tank 2 communicate with the outside.

[0073] The through hole communicates the second fuel tank 2 and the breather, which is convenient for the air inside the second fuel tank 2 to be discharged in time when refueling and for the oil to be easily discharged when taking the oil.

[0074] The breather 9 includes a two-way valve and a filter element, which ensures the air circulation when the second fuel tank 2 takes in and discharges oil, and at the same time ensures that the oil is not polluted by the outside when it remains in the second fuel tank 2. The breather 9 makes the second fuel tank 2 always in fluid communication with the outside atmosphere. When filling the second fuel tank 2 through the second oil return flow path 4, the oil will not be difficult to enter the second fuel tank 2 because the inside of the second fuel tank 2 is in a vacuum environment. When sampling from the second fuel tank 2, the oil in the second fuel tank 2 will not be difficult to flow out. The breather 9 is fixed to the first fuel tank 1 through a mounting seat 14, specifically connected to the mounting seat 14 through bolts 13 or flanges. The mounting seat 14 is welded to the first fuel tank 1.

[0075] Continue to see Figure 1 , in some embodiments, the fuel tank system of the construction vehicle further includes a protective cover 10. The breather 9 is located outside the second fuel tank 2, and the protective cover 10 is located outside the breather 9. The protective cover 10 plays a protective role for the breather 9, reducing or even avoiding the blockage of the breather 9 by foreign impurities from the outside.

[0076] Continue to see Figure 1, the first oil return flow path 3 includes a first pipeline 31 and a second pipeline 32. The first pipeline 31 is located outside the first fuel tank 1. One end of the second pipeline 32 extends out of the first fuel tank 1 and is in fluid communication with the first pipeline 31, and the other end of the second pipeline 32 extends into the bottom of the first fuel tank 1.

[0077] The other end of the second pipeline 32 is located at the bottom of the first fuel tank 1. On the premise that there is oil in the first fuel tank 1, the other end of the second pipeline 32 is located below the liquid level of the oil, and this oil will increase the oil return pressure of the oil flowing back through the second pipeline 32, that is, increase the oil return pressure of the first oil return flow path 3. Therefore, the oil return of the fuel system can branch off into the conducting second oil return flow path 4 under this pressure to achieve oil filling into the second fuel tank 2. The more oil there is in the first fuel tank 1, the deeper the position of the other end of the second pipeline 32, which is equivalent to the greater the oil return pressure. By controlling the liquid level of the oil in the first fuel tank 1, the oil return pressure of the first oil return flow path 3 can be controlled. This liquid level parameter is a known parameter of the engineering vehicle, so there is no need to design additional components, and the control of the oil return pressure is achieved almost imperceptibly to the vehicle user.

[0078] In some embodiments, the engineering vehicle fuel tank system further includes a liquid level sensor 8. The liquid level sensor 8 is disposed in the first fuel tank 1 and is configured to detect the oil level of the first fuel tank 1. Through the liquid level detected by the liquid level sensor 8, it can be accurately determined whether the other end of the second pipeline 32 is below the liquid level in the first fuel tank 1, so as to determine whether the oil return pressure of the first oil return flow path 3 is large enough.

[0079] In the above embodiments, the first fuel tank 1 and the second fuel tank 2 are configured to be independent and not in fluid communication with each other. That is, all the oil in the first fuel tank 1 comes from the first oil return flow path 3, and all the oil in the second fuel tank 2 comes from the second oil return flow path 4. The first fuel tank 1 and the second fuel tank 2 are two independent components and do not exchange oil with each other.

[0080] In the embodiments having the liquid level sensor 8, the parameter for controlling the opening of the second oil return flow path 4 can also be increased according to the liquid level of the first fuel tank 1 detected by the liquid level sensor 8. That is, when the liquid level of the first fuel tank 1 detected by the liquid level sensor 8 is not lower than the opening set value, the liquid level of the second fuel tank 2 detected by the liquid level switch 7 is lower than the oil filling lower limit value, and the three conditions that the engine is abnormal are all met, the controller 6 opens the switching valve 5 to conduct the second oil return flow path 4.

[0081] The liquid level corresponding to the opening set value of the first fuel tank 1 is the liquid level that can cover the end of the second pipeline 32, which can ensure the oil return pressure of the second pipeline 32. The oil filling lower limit value of the second fuel tank 2 is, for example, 20% - 40% of the volume of the second fuel tank 2.

[0082] Continue to refer to Figure 1 In some embodiments, the first oil return flow path 3 includes a first pipeline 31 and a second pipeline 32. The first pipeline 31 is located outside the first fuel tank 1. One end of the second pipeline 32 extends out of the first fuel tank 1 and is in fluid communication with the first pipeline 31, and the other end of the second pipeline 32 extends into the bottom of the second fuel tank 2. Extending the second pipeline 32 into the bottom of the first fuel tank 1 is beneficial to increasing the oil return pressure of the first oil return flow path 3 by using the oil in the first fuel tank 1, so that the oil can more smoothly enter the second fuel tank 2.

[0083] Refer to Figure 1 In some embodiments, the other end of the second pipeline 32 is configured to bend towards the top of the first fuel tank 1. The other end of the second pipeline 32 is configured to be bent, and the end of the bent end is at a certain distance from the liquid level of the first fuel tank 1. The greater this distance, the greater the oil return pressure. However, if the distance is too large, it may cause the bent section of the second pipeline 32 not to be located in the oil when the liquid level of the oil in the first fuel tank 1 is too low, then the oil return pressure of the first oil return flow path 3 will be too small, which may cause the second fuel tank 2 not to return oil preferentially. Therefore, the distance d of the bent section of the bent end of the second pipeline 32 is, for example, located between 20 mm and 70 mm, specifically, for example, 30 mm to 50 mm, so as to form the required oil return resistance and ensure that when the switching valve 5 is opened, the oil flows smoothly into the second fuel tank 2. Further, a certain oil return resistance can be maintained by adjusting the diameter of the second pipeline 32 and the value of the distance d to ensure that the oil flows into the second fuel tank 2.

[0084] Continue to refer to Figure 1 In some embodiments, the flow area of the first pipeline 31 is smaller than the flow area of the second pipeline 32. This enables the oil return to smoothly enter the second pipeline 32 and then flow into the first fuel tank 1.

[0085] Continue to refer to Figure 1 The fuel tank system of the engineering vehicle further includes a bracket 11. The bracket 11 is fixed inside the first fuel tank 1, and the bracket 11 is fixedly connected to the second pipeline 32, so that the second pipeline 32 is more firmly installed. When the engineering vehicle is in a harsh working condition, the second pipeline 32 is not easily displaced or loosened.

[0086] Refer to Figure 2 and Figure 3 The bracket 11 is in the shape of a rod or a plate. Both ends of the bracket 11 are welded and fixed to the inner wall of the first fuel tank 1. The middle part of the bracket 11 protrudes away from the inner wall of the first fuel tank 1, and the second pipeline 32 is inserted into the gap between the middle part of the bracket 11 and the inner wall of the first fuel tank 1.

[0087] Refer to Figure 4 , Figure 4The illustrated embodiment is different from the above embodiment in the following aspects: The second fuel tank 2 is located outside the first fuel tank 1. Except for the installation position of the second fuel tank 2 being different from that of the above embodiment, other contents can refer to the content introduced in the above embodiment.

[0088] An embodiment of the present invention further provides an engineering vehicle, including an engine and an engineering vehicle fuel tank system. The engine has a return oil branch. Both the first return oil flow path 3 and the second return oil flow path 4 are in fluid communication with the return oil branch.

[0089] The first return oil flow path 3 and the second return oil flow path 4 are independent. The first return oil flow path 3 is always in a conducting state, and the conducting and disconnecting states of the second return oil flow path 4 are controlled by a switching valve 5. In this way, the operation of storing oil in the second fuel tank 2 can be synchronized with the normal oil return operation, and there is no need to set a separate step to extract oil; and when the oil in the second fuel tank 2 is sufficient, the second return oil flow path 4 can be timely disconnected.

[0090] The other end of the second pipeline 32 is located below the liquid level in the first fuel tank 1, forming a necessary controllable oil return resistance to ensure that the oil enters the second fuel tank 2 normally when the switching valve 5 is opened. After the sampling is completed, the switching valve 5 is closed, and the second fuel tank 2 stores the oil normally without affecting the normal operation of the first fuel tank 1. After the diesel is released from the second fuel tank 2, the sampling process can be repeated.

[0091] See Figure 5 and Figure 6 , an embodiment of the present invention further provides an automatic sampling method for the oil of an engineering vehicle, which is implemented by using the engineering vehicle fuel tank system provided by any of the above technical solutions. The method includes the following steps:

[0092] Step S100: Determine whether the engine control component of the engineering vehicle where the engineering vehicle fuel tank system is located sends an abnormal signal. When some special abnormal signals appear in the engine, it may indicate vehicle failure, such as abnormal speed, abnormal power, etc.

[0093] Step S200: If the engine control component sends an abnormal signal, it means that the second fuel tank 2 needs to retain the sample oil, and the sample oil refers to the return oil of the fuel system of the engineering vehicle. Before filling the return oil into the second fuel tank 2, the second return oil flow path 4 is conducted.

[0094] The oil filling time into the second fuel tank 2 adopts the test set value, and this oil filling time corresponds to filling 60% - 80% of the oil into the second fuel tank 2.

[0095] In some embodiments, the following control steps are specifically adopted to conduct the second oil return flow path 4: If the engine control component issues an abnormal signal, it is judged whether the liquid level of the first fuel tank 1 is higher than the opening set value, and it is judged whether the liquid level of the second fuel tank 2 is lower than the lower limit value of oil filling. Two liquid level switches 7 can be respectively set for the high and low liquid levels of the second fuel tank 2, or a liquid level switch 7 capable of detecting the real-time liquid level of the second fuel tank 2 can be set. If the liquid level of the first fuel tank 1 is higher than the opening set value and the liquid level of the second fuel tank 2 is lower than the lower limit value of oil filling, the second oil return flow path 4 is conducted.

[0096] Step S300: A part of the engine's returned oil flows to the second fuel tank 2 via the second oil return flow path 4, and another part flows to the first fuel tank 1 via the first oil return flow path 3.

[0097] In other embodiments, the automatic oil sampling method for engineering vehicles further includes the following steps: When the oil in the second fuel tank 2 detected by the liquid level switch 7 reaches the upper limit value of oil filling, the second oil return flow path 4 is disconnected.

[0098] See Figure 6 , when the sample retention starts, the controller 6 first reads the signal of the liquid level sensor 8 of the first fuel tank 1, so as to judge whether the liquid level of the first fuel tank 1 is higher than the preset liquid level, ensure the oil return resistance of the first oil return flow path 3, and then reads the signal of the liquid level switch 7 of the second fuel tank 2 to judge whether there is a medium left in the first fuel tank 1. After meeting the conditions, the switching valve 5 is opened to start sample retention. After completing the sample retention, the controller 6 reads the signal of the liquid level switch 7 of the second fuel tank 2 and feeds it back to other terminals (or networks) to remind that the sample retention is successful and record it.

[0099] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for facilitating the description of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the protection content of the present invention.

[0100] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; Although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An engineering vehicle fuel tank system, characterized in that, Comprising: A first fuel tank (1), configured to store oil; A second fuel tank (2), also configured to store oil, and the volume of the second fuel tank (2) is smaller than the volume of the first fuel tank (1); A first oil return flow path (3), in fluid communication with the first fuel tank (1); and A second oil return flow path (4), in fluid communication with the second fuel tank (2); Wherein, the oil return sequence of the first oil return flow path (3) and the second oil return flow path (4) is controllable; Wherein, the oil return pressure of the first oil return flow path (3) is greater than or equal to the oil return pressure of the second oil return flow path (4); Wherein, the construction vehicle fuel tank system further comprises: A switching valve (5), disposed in the second oil return flow path (4), and the switching valve (5) is configured to switch the valve position to cause the second oil return flow path (4) to switch between an on state and an off state; A controller (6), electrically connected to the switching valve (5), and the controller (6) is configured to control the valve position of the switching valve (5) according to the operation signal of the engine of the construction vehicle, and to turn on the second oil return flow path (4) when the engine is in an abnormal condition; A liquid level switch (7), disposed at the top of the second fuel tank (2), and the liquid level switch (7) is electrically connected to the controller (6); the controller (6) is further configured to disconnect the second oil return flow path (4) when the liquid level of the second fuel tank (2) detected by the liquid level switch (7) is higher than a set value; and A sampling joint (12), installed in the second oil return flow path (4), and the sampling joint (12) is configured to communicate with a sampling pipeline to sample the oil in the second fuel tank (2); Wherein, the first fuel tank (1) and the second fuel tank (2) are configured to be independent and not in fluid communication with each other; the installation position of the second oil return flow path (4) is higher than the installation position of the first oil return flow path (3).

2. The fuel tank system of the construction vehicle according to claim 1, characterized in that, Further comprising: A liquid level sensor (8), disposed in the first fuel tank (1), and the liquid level sensor (8) is configured to detect the oil level of the first fuel tank (1).

3. The fuel tank system of the construction vehicle according to claim 1, characterized in that, Further comprising: A breather (9), there is a through hole (21) at the top cover of the second fuel tank (2), and the breather (9) is installed in the through hole (21) or the breather (9) covers the through hole (21), and the breather (9) is configured to communicate the second fuel tank (2) with the outside.

4. The fuel tank system of the construction vehicle according to claim 3, characterized in that Further comprising: A protective cover (10), the breather (9) is located outside the second fuel tank (2), and the protective cover (10) is located outside the breather (9).

5. The fuel tank system of the construction vehicle according to claim 1, characterized in that, The first oil return flow path (3) comprises: A first pipeline (31), located outside the first fuel tank (1); and A second pipeline (32), one end extending out of the first fuel tank (1) and in fluid communication with the first pipeline (31), and the other end extending into the bottom of the first fuel tank (1).

6. The fuel tank system of the construction vehicle according to claim 5, characterized in that, The other end of the second pipeline (32) is configured to be bent towards the top of the first fuel tank (1).

7. The fuel tank system of the construction vehicle according to claim 5, wherein, Further comprising: The bracket (11) is fixed to the inner wall of the first fuel tank (1), and the second pipeline (32) is fixed by the bracket (11).

8. The fuel tank system of the construction vehicle according to claim 1, characterized in that, The second fuel tank (2) is located inside the first fuel tank (1), and the second fuel tank (2) is located at the top of the first fuel tank (1); alternatively, the second fuel tank (2) is located outside the first fuel tank (1).

9. An engineering vehicle, characterized in that, Comprising: An engine having a return oil branch. And The construction vehicle fuel tank system according to any one of claims 1 to 8; Both the first return oil flow path (3) and the second return oil flow path (4) are in fluid communication with the return oil branch.

10. An automatic oil sampling method for engineering vehicles, characterized in that, Implemented by using the construction vehicle fuel tank system according to any one of claims 1 to 8, the method comprising the following steps: Determine whether the engine control component of the construction vehicle where the construction vehicle fuel tank system is located emits an abnormal signal; If the engine control component emits an abnormal signal, then conduct the second return oil flow path; A part of the return oil of the engine flows to the second fuel tank via the second return oil flow path, and another part flows to the first fuel tank via the first return oil flow path.

11. The automatic oil sampling method for engineering vehicles according to claim 10, characterized in that, The step of if the engine control component emits an abnormal signal, then conduct the second return oil flow path specifically includes the following steps: If the engine control component emits an abnormal signal, then determine whether the liquid level of the first fuel tank is higher than the opening set value, and determine whether the liquid level of the second fuel tank is lower than the oil filling lower limit value; If the liquid level of the first fuel tank is higher than the opening set value and the liquid level of the second fuel tank is lower than the oil filling lower limit value, then conduct the second return oil flow path.

12. The automatic oil sampling method for engineering vehicles according to claim 11, characterized in that, Further comprising the following steps: When the oil liquid in the second fuel tank detected by the liquid level switch reaches the set value, disconnect the second return oil flow path.

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