Liquid level adjusting system of electric drive assembly and control method of liquid level adjusting system

Abstract

The invention relates to the technical field of electric drive assembly lubrication, and discloses a liquid level adjusting system and a control method thereof.The system comprises an oil storage device arranged in a shell of an electric drive assembly and used for storing lubricating oil; the liquid level detection device is at least partially arranged in the oil storage device and used for detecting the liquid level height of the lubricating oil in the oil storage device; the oil pump is arranged in the shell, one end of the oil pump is communicated with the oil storage device, the other end of the oil pump is communicated with the oil bottom shell of the shell, and the oil pump is used for pumping the lubricating oil in the oil storage device into the oil bottom shell of the shell or pumping the lubricating oil in the oil bottom shell into the oil storage device; the control device is connected with the liquid level detection device and the oil pump and used for controlling the oil pump to work based on the liquid level height of the lubricating oil in the oil storage tank so as to adjust the liquid level height of the lubricating oil in the oil storage device and the oil pan. Therefore, through the arrangement of the oil storage device and the oil pump communicated with the oil storage device, the liquid level can be adjusted through the oil pump.

Description

Technical Field

[0001] The present application relates to the technical field of electric drive assembly lubrication, and in particular to a liquid level regulation system for an electric drive assembly and a control method thereof. Background Art

[0002] In pure electric vehicles and extended-range vehicles, the electric drive system is the only source of driving force for the vehicle. It provides all the driving force for the vehicle and ensures the vehicle's driving dynamics, smoothness and other performance. Its function is equivalent to the engine and gearbox of a traditional car.

[0003] At present, electric drive assemblies mainly rely on gears to stir the lubricating oil, and the splashing lubricating oil lubricates the bearings and gears. The lubrication effect will be different when the lubricating oil level is different. When the vehicle is in different working conditions, different liquid levels are often required, but the liquid level cannot be adjusted according to the actual situation. Summary of the invention

[0004] In view of the above problems, the present application provides a liquid level regulation system of an electric drive assembly and a control method thereof. By providing an oil storage device and an oil pump connected thereto, the liquid level can be regulated by the oil pump.

[0005] In a first aspect, the present application provides a liquid level regulating system for an electric drive assembly, comprising: an oil storage device, disposed in a housing of the electric drive assembly, and used to store lubricating oil; a liquid level detecting device, at least partially disposed in the oil storage device, and used to detect the liquid level height of the lubricating oil in the oil storage device; an oil pump, disposed in the housing, one end of the oil pump being connected to the oil storage device, and the other end of the oil pump being connected to the oil sump of the housing, and the oil pump being used to draw the lubricating oil in the oil storage device into the oil sump of the housing, or to draw the lubricating oil in the oil sump into the oil storage device; a control device, connected to the liquid level detecting device and the oil pump, and used to control the operation of the oil pump based on the liquid level height of the lubricating oil in the oil storage tank, so as to adjust the liquid level height of the lubricating oil in the oil storage device and the oil sump.

[0006] In some specific embodiments, the liquid level detection device includes a liquid level sensor, which is disposed in the oil storage tank and extends in a vertical direction. The liquid level sensor generates different sensing signals when the length of the liquid level sensor immersed in the lubricating oil is different.

[0007] A second aspect of the present application provides a liquid level adjustment method for an electric drive assembly, which is applied to the liquid level adjustment system of any of the above-mentioned electric drive assemblies, and the method includes: detecting the current liquid level of the lubricating oil in the oil storage device by a liquid level detection device, and obtaining the current working state of the vehicle; determining the target liquid level of the lubricating oil in the oil storage device according to the current working state of the vehicle; wherein the working state of the vehicle and the target liquid level have a preset corresponding relationship; detecting whether the current liquid level is consistent with the target liquid level, and controlling the oil pump to adjust the liquid level of the lubricating oil in the oil storage device to the target liquid level when they are inconsistent.

[0008] In some specific embodiments, the step of detecting whether the current liquid level is consistent with the target liquid level includes: detecting whether the current liquid level is within a floating height range; wherein the minimum value of the floating height range is the difference between the target liquid level and a preset floating value, and the maximum value is the sum of the target liquid level and the preset floating value; if the current liquid level is within the floating height range, it is determined that the current liquid level is consistent with the target liquid level.

[0009] In some specific embodiments, before the step of detecting whether the current liquid level is within the floating height range, the step includes: obtaining the degree of bumpiness of the vehicle within a preset historical period; wherein the duration of the preset historical period is a preset duration, and the end time of the preset historical period is the current time; determining a first floating adjustment value according to the preset bumpiness range in which the bumpiness is located, and adjusting the preset floating base value by the first floating adjustment value to obtain a preset floating value; wherein the preset bumpiness range corresponds to the first floating adjustment value, and the greater the bumpiness, the greater the first floating adjustment value corresponding to the preset bumpiness range.

[0010] In some specific embodiments, before the step of detecting whether the current liquid level is within the floating height range, the step includes: determining a preset speed range in which the current vehicle speed is located; wherein, there are multiple preset speed ranges and they do not overlap with each other; determining a second floating adjustment value according to the preset speed range, and adjusting the preset floating base value by the second floating adjustment value to obtain a preset floating value; wherein, the preset speed range corresponds to the second floating adjustment value, and the higher the vehicle speed, the larger the second floating adjustment value corresponding to the preset speed range.

[0011] In some specific embodiments, the step of obtaining the current working state of the vehicle includes: detecting whether the vehicle is in a preset limit operating condition, and obtaining the current vehicle speed of the vehicle when it is not in the preset limit operating condition; the step of determining the target liquid level height of the lubricating oil in the oil storage device according to the current working state of the vehicle includes: determining a preset vehicle speed range in which the current vehicle speed is located; wherein the preset vehicle speed ranges are multiple and do not overlap with each other; determining the target liquid level height of the lubricating oil in the oil storage device according to the preset vehicle speed range; wherein the preset vehicle speed range corresponds to the target liquid level height, and the higher the average vehicle speed, the higher the target liquid level height corresponding to the preset vehicle speed range.

[0012] In some specific embodiments, the step of detecting whether the vehicle is in a preset extreme operating condition includes: obtaining the current wheel speed difference between the left and right wheels connected to the electric drive assembly; if the current wheel speed difference is greater than the preset wheel speed difference, determining that the vehicle is in a first preset extreme operating condition.

[0013] In some specific embodiments, the step of detecting whether the vehicle is in a preset limit operating condition includes: obtaining the current slope of the road on which the vehicle is traveling; if the current slope is greater than the preset slope, determining that the vehicle is in a second preset limit operating condition.

[0014] In some specific embodiments, the step of determining the target liquid level of the lubricating oil in the oil storage device according to the current working state of the vehicle includes: if the vehicle is in a first extreme operating condition or a second extreme operating condition, determining the target liquid level of the lubricating oil in the oil storage device to be the minimum liquid level.

[0015] The present application has at least the following beneficial technical effects: Based on the liquid level regulating system and control method provided by the present application, the system includes: an oil storage device, which is arranged in the housing of the electric drive assembly and is used to store lubricating oil; a liquid level detection device, which is at least partially arranged in the oil storage device, and the liquid level detection device is used to detect the liquid level of the lubricating oil in the oil storage device; an oil pump, which is arranged in the housing, one end of the oil pump is connected to the oil storage device, and the other end of the oil pump is connected to the oil pan of the housing, and the oil pump is used to extract the lubricating oil in the oil storage device into the oil pan of the housing, or extract the lubricating oil in the oil pan into the oil storage device; a control device, which is connected to the liquid level detection device and the oil pump, and the control device is used to control the operation of the oil pump based on the liquid level of the lubricating oil in the oil storage tank, so as to adjust the liquid level of the lubricating oil in the oil storage device and the oil pan. Therefore, by setting the oil storage device and the oil pump connected thereto, the liquid level can be adjusted by the oil pump.

[0016] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are only used to illustrate the embodiments and are not to be considered as limiting the present application. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings. In the accompanying drawings:

[0018] Figure 1 It is a structural schematic diagram of an embodiment of a liquid level regulating system of an electric drive assembly provided in the present application;

[0019] Figure 2 It is a flow chart of an embodiment of a liquid level adjustment method of an electric drive assembly provided in the present application;

[0020] Figure 3 is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided by the present application;

[0021] Figure 4 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application;

[0022] Figure 5 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application;

[0023] Figure 6 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application;

[0024] Figure 7 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application;

[0025] Figure 8 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application;

[0026] Description of reference numerals: liquid level regulating system 10 of electric drive assembly, oil storage device 11, liquid level detection device 12, oil pump 13, control device 14;

[0027] Housing 21 , oil pan 211 , input shaft gear 22 , output shaft gear 23 , differential gear 24 . DETAILED DESCRIPTION

[0028] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0029] If there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features limited to "first" and "second" may explicitly or implicitly include at least one of the features. In addition, if the meaning of "and / or" appearing in the full text is to include three parallel schemes, taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0030] In a first aspect, the present application provides a liquid level regulating system 10 for an electric drive assembly. Figure 1 It is a structural schematic diagram of an embodiment of a liquid level regulation system 10 of an electric drive assembly provided in the present application.

[0031] Combination Figure 1 The liquid level regulating system 10 of the electric drive assembly includes an oil storage device 11, a liquid level detection device 12, an oil pump 13 and a control device 14. The control device 14 is connected to the liquid level detection device 12 and the oil pump 13. The control device 14 is used to receive liquid level detection information from the liquid level detection device 12 and realize control of the oil pump 13.

[0032] The oil storage device 11 is disposed in the housing 21 of the electric drive assembly, and is used to store lubricating oil. The oil storage device 11 is provided with a receiving chamber, and the lubricating oil can be received in the receiving chamber. The oil storage device 11 can form the receiving chamber independently, or can form the receiving chamber together with other structures, and no specific limitation is made here. It should be understood that in Figure 1 The oil storage device 11 is exemplarily shown as a trough structure, and together with other structures forms a containing cavity.

[0033] Among them, at least part of the liquid level detection device 12 is arranged in the oil storage device 11, and the liquid level detection device 12 may be arranged in its entirety in the accommodating cavity of the oil storage device 11, or part of the liquid level detection device 12 may be arranged in the accommodating cavity. At this time, the liquid level detection device 12 is used to detect the liquid level height of the lubricating oil in the oil storage device 11. The liquid level detection device 12 can detect and obtain liquid level detection information of the lubricating oil, and send the liquid level detection information to the control device 14, so that the control device 14 can obtain the liquid level of the lubricating oil by analyzing the liquid level detection information.

[0034] The oil pump 13 is disposed in the housing 21, one end of the oil pump 13 is connected to the oil storage device 11, and the other end of the oil pump 13 is connected to the oil pan 211. The oil pump 13 is used to extract the lubricating oil in the oil storage device 11 into the oil pan 211 of the housing 21, or to extract the lubricating oil in the oil pan 211 into the oil storage device 11. At this time, the lubricating oil in the oil storage device 11 and the lubricating oil in the oil pan 211 can be connected through a pipeline, and the oil pump 13 can be disposed in the pipeline to realize the extraction of lubricating oil between the two.

[0035] The housing 21 may be the housing of the gearbox of the electric drive system, the oil pan 211 is the lower part of the housing 21, and a large amount of lubricating oil is stored in the oil pan 211. L is the liquid level of the lubricating oil in the oil pan 211. The housing 21 is also provided with an input shaft gear 22, an output shaft gear 23 and a differential gear 24. The input shaft gear 22 is connected to the output shaft of the drive motor, and the output shaft gear 23 is driven to rotate by the input shaft gear 22, and the output shaft gear 23 drives the differential gear 24 to rotate. At this time, the lubricating oil can achieve lubrication of the input shaft gear 22, the output shaft gear 23 and the differential gear 24, and mainly achieves lubrication of the differential gear 24. In combination with the above content, the liquid level height of the lubricating oil in the oil pan 211 will affect the lubrication effect of the gears, bearings, etc. in the housing 21.

[0036] In combination with the above, when the control device 14 obtains the liquid level of the lubricating oil in the oil storage device 11, since the amount of the lubricating oil in the assembly is roughly maintained at a certain amount, the liquid level of the lubricating oil in the oil pan 211 can be obtained. At this time, the control device 14 controls the operation of the oil pump 13 based on the liquid level of the lubricating oil in the oil storage tank, which is actually controlling the operation of the oil pump 13 based on the liquid level of the lubricating oil in the oil pan 211, so as to adjust the liquid level of the lubricating oil in the oil storage device 11 and the oil pan 211, which is actually adjusting the liquid level of the liquid in the oil pan 211 to meet different lubrication requirements.

[0037] It should be understood that the operation of the gears and the bumps of the vehicle will cause the liquid level to fluctuate greatly, and the oil storage capacity of the oil storage device 11 is less than the oil storage capacity of the oil pan 211, and the detection device is arranged in the oil storage device 11, so it is less affected by the operation of the gears and the bumps of the vehicle, and the lubricating oil liquid level fluctuates less. Therefore, the liquid level height of the oil storage device 11 detected by the liquid level detection device 12 is relatively accurate, and thus the calculated liquid level height of the oil pan 211 is more accurate, which enables the control device 14 to control the operation of the oil pump 13 based on the more accurate liquid level height in the oil pan 211, and the adjustment of the liquid level height of the oil pan 211 is more accurate.

[0038] It should be understood that the working state of the vehicle often changes during driving. Under different working states, the vehicle often requires different liquid levels of the lubricating oil in the oil pan 211. The liquid level adjustment system 10 of the electric drive assembly provided in the above embodiment can adjust the liquid level of the lubricating oil in the oil pan 211, thereby providing a basis for adapting to the actual needs of the liquid level under different working states.

[0039] Furthermore, in some specific embodiments, the liquid level detection device 12 includes a liquid level sensor, which is disposed in the oil storage tank and extends in the vertical direction. The liquid level sensor generates different sensing signals when the length of the liquid level sensor immersed in the lubricating oil is different.

[0040] like Figure 1 As shown, the liquid level detection device 12 only shows a vertically extending liquid level sensor, the length direction of the liquid level sensor is consistent with the vertical direction, and the length of the liquid level sensor is greater than the maximum depth of the lubricating oil. In some application scenarios, the liquid level sensor can be a capacitive liquid level sensor. When the lubricating oil has different liquid level heights, the capacitive liquid level sensor will have different capacitance values. At this time, the capacitance value is the sensing information obtained by the liquid level detection device 12, and the liquid level height can be obtained through the specific capacitance value.

[0041] A second aspect of the present application provides a liquid level regulating method for an electric drive assembly, which is applied to the liquid level regulating system 10 of the electric drive assembly in any of the above embodiments. Figure 2 1 is a flow chart of an embodiment of a liquid level adjustment method for an electric drive assembly provided in the present application. Figure 2 , the method comprises the following steps:

[0042] S101: Detect the current liquid level of the lubricating oil in the oil storage device through a liquid level detection device, and obtain the current working state of the vehicle.

[0043] The current liquid level may be detected during vehicle driving, because the lubrication requirements for gears, etc. are high during vehicle driving. In combination with the above content, when the current liquid level of the oil storage device is obtained, the current liquid level of the lubricating oil in the oil pan can be obtained.

[0044] The current working state of the vehicle reflects the current specific driving state of the vehicle, and the current working state may include the driving state of the vehicle itself, and may also include the environmental state of the environment in which the vehicle is located. It should be understood that the requirements for the lubricating oil level in the oil pan are different under different driving states or environmental states.

[0045] S102: Determine a target liquid level height of the lubricating oil in the oil storage device according to the current working state of the vehicle; wherein the working state of the vehicle and the target liquid level height have a preset corresponding relationship.

[0046] Combined with the above content, it can be seen that when the vehicle is in different working states, the requirements for the liquid level in the oil pan are different, that is, the target liquid level requirements for the lubricating oil in the oil storage device are different. Among them, the target liquid level under different working states can be determined by calibration, and a preset corresponding relationship can be established and stored. When the current working state is obtained, the corresponding target liquid level can be directly obtained according to the preset corresponding relationship.

[0047] S103: Detect whether the current liquid level is consistent with the target liquid level, and if not, control the oil pump to adjust the liquid level of the lubricating oil in the oil storage device to the target liquid level.

[0048] It should be understood that the target liquid level is the liquid level that the oil storage device needs to have under the current working state. When the current liquid level is inconsistent with the target liquid level, it means that the current liquid level does not meet the corresponding target liquid level under the current working state, that is, it does not meet the requirements for the lubricating oil level in the oil pan under the current working state. At this time, we need to control the oil pump to adjust the liquid level of the lubricating oil in the oil storage device to the target liquid level, so that the liquid level of the lubricating oil in the oil pan can meet the specific requirements under the current working state.

[0049] In summary, based on this embodiment, on the basis of the liquid level adjustment system of the electric drive assembly, the target liquid level height is determined according to the current working state, and then the liquid level height of the lubricating oil in the oil storage device is adjusted to the target liquid level height, which can meet the liquid level requirements for the lubricating oil in the oil pan under the current working state.

[0050] Figure 3 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application.

[0051] Combination Figure 3 In some specific embodiments, the step of detecting whether the current liquid level is consistent with the target liquid level includes:

[0052] S201: Detect whether the current liquid level is within the floating height range; wherein the minimum value of the floating height range is the difference between the target liquid level and the preset floating value, and the maximum value is the sum of the target liquid level and the preset floating value.

[0053] It should be understood that the liquid level in the oil storage device may fluctuate due to the influence of vehicle vibration, driving environment, etc. At this time, even if the total amount of lubricating oil in the oil storage device remains unchanged, the detected current liquid level may fluctuate within a certain range.

[0054] Therefore, when the actual liquid level of the oil storage device is the target liquid level, the current liquid level detected may fluctuate above and below the target liquid level. Although it fluctuates, the actual liquid level is equal to the target liquid level. In order to avoid frequent adjustment of the liquid level resulting in inaccurate adjustment, the present embodiment sets a preset floating value, and then obtains the floating height range through the preset floating value. At this time, as long as the current liquid level is within the floating height range, it is considered that the current liquid level is consistent with the target liquid level.

[0055] S202: If the current liquid level is within the floating height range, determine whether the current liquid level is consistent with the target liquid level.

[0056] At this time, since it is determined that the current liquid level is consistent with the target liquid level, there is no need to adjust the liquid level of the oil storage device.

[0057] Figure 4 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application.

[0058] Combination Figure 4 In some specific embodiments, before the step of detecting whether the target liquid level is within the floating height range, that is, before the above step S201, the following steps are included:

[0059] S301: Obtain the degree of turbulence of the vehicle within a preset historical period; wherein the duration of the preset historical period is a preset duration, and the end time of the preset historical period is the current time.

[0060] The preset duration can be set to a relatively short time, such as one hour. The degree of bumping can be assessed in a variety of ways, such as by using existing methods for assessing the degree of bumping, which is not specifically limited here. The greater the degree of bumping, the more severe the vehicle bumps.

[0061] It should be understood that since the preset time duration is not long and is connected to the current moment, the degree of bumpiness within the preset historical period reflects the current degree of bumpiness of the vehicle to a certain extent.

[0062] S302: Determine a first floating adjustment value according to a preset bumpiness range in which the bumpiness degree is located, and adjust the preset floating base value by the first floating adjustment value to obtain a preset floating value; wherein, the preset bumpiness range corresponds to the first floating adjustment value, and a larger bumpiness range corresponds to a larger first floating adjustment value.

[0063] At this time, there may be multiple preset ranges of bumpiness, and the relationship between the preset range of bumpiness and the first floating adjustment value may be preset and saved. After the bumpiness is obtained, the preset range of bumpiness in which it is located can be obtained, and then the first floating adjustment value is determined.

[0064] The preset floating base value is preset and may be a fixed value. In some application scenarios, the preset floating base value is adjusted by the first floating adjustment value to obtain the preset floating value, and the sum of the first floating adjustment value and the preset floating base value may be used as the preset floating value.

[0065] It should be understood that when the bumpiness of the vehicle is greater, the lubricating oil level may fluctuate more, so it is necessary to set the first floating adjustment value to be larger, thereby making the determined preset floating value larger.

[0066] Figure 5 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application.

[0067] Combination Figure 5 In some specific embodiments, before the step of detecting whether the target liquid level is within the floating height range, that is, before the above step S201, the following steps are included:

[0068] S401: Determine a preset speed range within which the current speed of the vehicle is located; wherein there are multiple preset speed ranges that do not overlap with each other.

[0069] After the current vehicle speed is obtained, the preset vehicle speed range can be directly determined. Among them, the number of settings of the current vehicle speed range can be large to meet the refined scene requirements.

[0070] S402: Determine a second floating adjustment value according to a preset vehicle speed range, and adjust the preset floating base value by the second floating adjustment value to obtain a preset floating value; wherein, the preset vehicle speed range corresponds to the second floating adjustment value, and the higher the vehicle speed, the larger the second floating adjustment value corresponding to the preset vehicle speed range.

[0071] It should be understood that the greater the current vehicle speed, the greater the fluctuation of the lubricating oil level generally is, so this embodiment sets the second floating adjustment value corresponding to the preset vehicle speed range with a higher vehicle speed to be larger.

[0072] Similarly, in this embodiment, the preset floating base value is adjusted by the second floating adjustment value to obtain the preset floating value, and the sum of the second floating adjustment value and the preset floating base value may be used as the preset floating value.

[0073] In combination with the above two embodiments, the first floating adjustment value and the second floating adjustment value can be obtained. At this time, the sum of the first floating adjustment value, the second floating adjustment value and the preset floating basic value can be used as the preset floating value. At this time, the influence of vehicle speed and vehicle bumps on liquid level fluctuations is considered at the same time.

[0074] Figure 6FIG. 1 is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application. In some specific embodiments, the step of obtaining the current working state of the vehicle includes:

[0075] S501: Detect whether the vehicle is in a preset limit operating condition, and obtain the current speed of the vehicle if it is not in the preset limit operating condition.

[0076] It should be understood that the type of preset limit operating condition is preset, and when the vehicle is in the preset limit operating condition, the liquid level height of the oil pan is required to be higher, and this application treats it as a special case separately. This embodiment mainly discusses the setting method for the target liquid level height under non-preset limit operating conditions.

[0077] The step of determining the target liquid level of the lubricating oil in the oil storage device according to the current working state of the vehicle, i.e., the above-mentioned step S102, comprises:

[0078] S502: Determine a preset vehicle speed range within which the current vehicle speed is located; wherein there are multiple preset vehicle speed ranges that do not overlap with each other.

[0079] Similarly, a plurality of preset vehicle speed ranges are pre-set, and more than one of them can be set. Among them, a plurality of preset vehicle speed ranges can be connected to form a continuous wider vehicle speed range.

[0080] S503: Determine a target liquid level height of the lubricating oil in the oil storage device according to a preset vehicle speed range; wherein the preset vehicle speed range corresponds to the target liquid level height, and the preset vehicle speed range with a higher average vehicle speed corresponds to a higher target liquid level height.

[0081] It should be understood that when the vehicle is at a high speed, the gears will run at a high speed and the gears will stir the lubricating oil. When the liquid level of the lubricating oil in the oil pan is high, it will cause a large oil stirring power loss. Therefore, in order to reduce the oil stirring power loss at high speeds, this embodiment sets the target liquid level corresponding to the speed range with a higher average speed to be lower, that is, the corresponding lubricating oil level in the oil pan is lower.

[0082] Figure 7 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application.

[0083] Combination Figure 7 In some specific embodiments, the step of detecting whether the vehicle is in a preset limit operating condition includes:

[0084] S701: Obtain the current wheel speed difference between the left and right wheels connected to the electric drive assembly.

[0085] It should be understood that the current wheel speed difference between the left and right wheels connected to the electric drive assembly reflects the working intensity of the differential of the electric drive assembly and the lubrication intensity required by the differential gear. The greater the current wheel speed difference, the higher the working intensity of the differential, the higher the lubrication intensity required by the differential gear, and the higher the oil pan level required.

[0086] S702: If the current wheel speed difference is greater than the preset wheel speed difference, it is determined that the vehicle is in a first preset limit operating condition.

[0087] The preset wheel speed difference is preset, and when the current wheel speed difference is greater than the preset wheel speed difference, it means that the current wheel speed difference is large, and a higher oil pan liquid level is required at this time. At this time, the corresponding vehicle working state is the first limit working condition.

[0088] Among them, when the vehicle is in a situation where one side of the tire is stuck in a mud pit, on an icy or snowy road, or one side of the tire is slipping, it is easy for the wheel speed difference to be greater than the preset wheel speed difference.

[0089] Figure 8 It is a flow chart of another embodiment of the liquid level adjustment method of the electric drive assembly provided in the present application.

[0090] Combination Figure 8 In some specific embodiments, the step of detecting whether the vehicle is in a preset limit operating condition includes:

[0091] S801: Obtain the current slope of the road on which the vehicle is traveling.

[0092] Specifically, the current slope of the driving road may be acquired through sensors, etc. In some application scenarios, the relevant steps of this embodiment may be performed only when the driving time on the slope in a preset historical period reaches a preset duration.

[0093] S802: If the current slope is greater than the preset slope, it is determined that the vehicle is in a second preset limit operating condition.

[0094] It should be understood that when the current slope is greater than the preset slope, it means that the vehicle is on a steeper road, and the liquid level in the oil pan will present a larger inclination angle. In the oil pan, there is an oil pump for pumping lubricating oil to certain specific components that need lubrication. At this time, due to the inclination of the liquid level, it is very likely that the oil pump will be emptied, resulting in failure to achieve a good lubrication effect for other components, causing these components to work abnormally or even be damaged. At this time, we need to set the liquid level in the oil pan higher to avoid the oil pump being emptied.

[0095] In this embodiment, we regard the driving condition where the front slope is greater than the preset slope as the second preset limit condition of the vehicle.

[0096] In combination with the above embodiments, in some specific embodiments, the step of determining the target liquid level height of the lubricating oil in the oil storage device according to the current working state of the vehicle includes: if the vehicle is in the first extreme operating condition or the second extreme operating condition, then determining the target liquid level height of the lubricating oil in the oil storage device to be the minimum liquid level height.

[0097] Combined with the above content, it can be seen that in the first extreme working condition or the second extreme working condition, the requirements for the liquid level of the oil pan are both relatively high. Therefore, in this embodiment, we set the target liquid level to the minimum liquid level, and the liquid level in the oil pan is the maximum liquid level at this time.

[0098] In summary, based on the liquid level regulating system and control method thereof provided by the present application, the system includes: an oil storage device, which is arranged in the housing of the electric drive assembly and is used to store lubricating oil; a liquid level detection device, which is at least partially arranged in the oil storage device, and the liquid level detection device is used to detect the liquid level of the lubricating oil in the oil storage device; an oil pump, which is arranged in the housing, one end of the oil pump is connected to the oil storage device, and the other end of the oil pump is connected to the oil pan of the housing, and the oil pump is used to extract the lubricating oil in the oil storage device into the oil pan of the housing, or extract the lubricating oil in the oil pan into the oil storage device; a control device, which is connected to the liquid level detection device and the oil pump, and the control device is used to control the operation of the oil pump based on the liquid level of the lubricating oil in the oil storage tank, so as to adjust the liquid level of the lubricating oil in the oil storage device and the oil pan. Therefore, the liquid level can be adjusted by the oil pump, and then the liquid level can be adjusted according to the working state of the vehicle, so as to meet the actual demand of the vehicle for the lubricating oil level under different working states.

[0099] The above content is only a preferred exemplary embodiment of the present application and is not intended to limit the implementation scheme of the present application. A person skilled in the art can easily make corresponding changes or modifications based on the main concept and spirit of the present application. Therefore, the scope of protection of the present application shall be based on the scope of protection required by the claims.

Claims

1. A liquid level regulating system for an electric drive assembly, characterized in that: include: An oil storage device, disposed in the housing of the electric drive assembly, for storing lubricating oil; a liquid level detection device, at least partially disposed in the oil storage device, the liquid level detection device being used to detect the liquid level of the lubricating oil in the oil storage device; an oil pump, disposed in the housing, one end of the oil pump being connected to the oil storage device, and the other end of the oil pump being connected to the oil sump of the housing, the oil pump being used to pump the lubricating oil in the oil storage device into the oil sump of the housing, or to pump the lubricating oil in the oil sump into the oil storage device; A control device is connected to the liquid level detection device and the oil pump, and is used to control the operation of the oil pump based on the liquid level of the lubricating oil in the oil storage tank to adjust the liquid level of the lubricating oil in the oil storage device and the oil pan.

2. The liquid level regulating system of the electric drive assembly according to claim 1, characterized in that: The liquid level detection device comprises a liquid level sensor, which is arranged in the oil storage tank and extends in a vertical direction. The liquid level sensor generates different sensing signals when the length of the liquid level sensor immersed in the lubricating oil is different.

3. A method for adjusting the liquid level of an electric drive assembly, characterized in that: The method is applied to the liquid level regulating system of the electric drive assembly according to claim 1 or 2, and the method comprises: Detecting the current liquid level of the lubricating oil in the oil storage device by means of a liquid level detection device, and obtaining the current working state of the vehicle; Determining a target liquid level height of the lubricating oil in the oil storage device according to the current working state of the vehicle; wherein the working state of the vehicle and the target liquid level height have a preset corresponding relationship; Detect whether the current liquid level is consistent with the target liquid level, and if not, control the oil pump to adjust the liquid level of the lubricating oil in the oil storage device to the target liquid level.

4. The liquid level adjustment method according to claim 3, characterized in that: The step of detecting whether the current liquid level is consistent with the target liquid level comprises: Detecting whether the current liquid level is within a floating height range; wherein the minimum value of the floating height range is the difference between the target liquid level and a preset floating value, and the maximum value is the sum of the target liquid level and the preset floating value; If the current liquid level is within the floating height range, it is determined that the current liquid level is consistent with the target liquid level.

5. The liquid level adjustment method according to claim 4, characterized in that: Before the step of detecting whether the current liquid level is within the floating height range, the method includes: Obtaining the degree of turbulence of the vehicle within a preset historical period; wherein the duration of the preset historical period is a preset duration, and the end time of the preset historical period is the current time; A first floating adjustment value is determined according to the preset bumpiness range in which the bumpiness degree is located, and the preset floating base value is adjusted by the first floating adjustment value to obtain a preset floating value; wherein, the preset bumpiness range corresponds to the first floating adjustment value, and the greater the bumpiness degree, the greater the first floating adjustment value corresponding to the preset bumpiness range.

6. The liquid level adjustment method according to claim 4, characterized in that: Before the step of detecting whether the current liquid level is within the floating height range, the method includes: Determine a preset speed range within which the current speed of the vehicle is located; wherein the preset speed ranges are multiple and do not overlap with each other; A second floating adjustment value is determined according to the preset vehicle speed range, and the preset floating base value is adjusted by the second floating adjustment value to obtain the preset floating value; wherein, the preset vehicle speed range corresponds to the second floating adjustment value, and the higher the vehicle speed, the larger the second floating adjustment value corresponding to the preset vehicle speed range.

7. The liquid level adjustment method according to claim 3, characterized in that: The step of obtaining the current working state of the vehicle comprises: Detecting whether the vehicle is in a preset limit operating condition, and obtaining a current speed of the vehicle when the vehicle is not in the preset limit operating condition; The step of determining a target liquid level height of the lubricating oil in the oil storage device according to the current working state of the vehicle comprises: Determine a preset vehicle speed range within which the current vehicle speed is located; wherein the preset vehicle speed ranges are multiple and do not overlap with each other; The target liquid level of the lubricating oil in the oil storage device is determined according to the preset vehicle speed range; wherein the preset vehicle speed range corresponds to the target liquid level, and the higher the average vehicle speed, the higher the target liquid level corresponding to the preset vehicle speed range.

8. The liquid level adjustment method according to claim 7, characterized in that: The step of detecting whether the vehicle is in a preset limit operating condition comprises: Obtaining a current wheel speed difference between left and right wheels connected to the electric drive assembly; If the current wheel speed difference is greater than the preset wheel speed difference, it is determined that the vehicle is in a first preset limit operating condition.

9. The liquid level adjustment method according to claim 7, characterized in that: The step of detecting whether the vehicle is in a preset limit operating condition comprises: Obtaining the current slope of the road on which the vehicle is traveling; If the current slope is greater than the preset slope, it is determined that the vehicle is in a second preset limit operating condition.

10. The liquid level adjustment method according to claim 8 or 9, characterized in that: The step of determining a target liquid level height of the lubricating oil in the oil storage device according to the current working state of the vehicle comprises: If the vehicle is in the first limit operating condition or the second limit operating condition, the target liquid level height of the lubricating oil in the oil storage device is determined to be the minimum liquid level height.

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