Lubrication control device

Abstract

To provide a lubrication control device capable of suppressing increase of friction and shortage of lubrication.SOLUTION: The lubrication control device includes a motor chamber that accommodates a motor, a gear chamber that accommodates a speed reduction unit and a differential unit connected to the motor, a first oil passage for supplying oil to the motor chamber, a second oil passage for supplying oil to the gear chamber, an oil pump that supplies oil to the first oil passage and the second oil passage, and an oil amount adjusting unit that adjusts an amount of oil supplied to the motor chamber and the gear chamber according to a motor rotation speed, a gear rotation speed, a lateral acceleration, and an oil temperature.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a lubrication control device. [Background technology]

[0002] Patent Document 1 discloses a technique for calculating an optimum amount of oil to be supplied to gears based on the running state of a vehicle, and adjusting the amount of oil according to the calculated amount of oil to be supplied. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-180514 Summary of the Invention [Problem to be solved by the invention]

[0004] In the technology disclosed in Patent Document 1, when the lateral acceleration (lateral G) of the vehicle increases due to left or right turns, the oil level may tilt, resulting in increased friction or insufficient lubrication.

[0005] The present disclosure has been made in view of the above, and aims to provide a lubrication control device that can suppress an increase in friction and insufficient lubrication. [Means for solving the problem]

[0006] The lubrication control device of the present disclosure comprises a motor chamber that houses a motor, a gear chamber that houses a reduction unit and a differential unit connected to the motor, a first oil passage for supplying oil to the motor chamber, a second oil passage for supplying the oil to the gear chamber, an oil pump that supplies the oil to the first oil passage and the second oil passage, and an oil quantity adjustment unit that adjusts the amount of oil supplied to the motor chamber and the gear chamber depending on the motor rotation speed, gear rotation speed, lateral acceleration, and oil temperature. [Effects of the Invention]

[0007] According to the present disclosure, even when lateral acceleration occurs, the amount of oil in the motor chamber and the gear chamber can be optimally controlled, thereby suppressing increased friction and insufficient lubrication. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a schematic configuration of a vehicle drive unit for realizing a lubrication control device according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of a control flow by the lubrication control device according to the embodiment. [Figure 3] FIG. 3 is a diagram showing a schematic configuration of a vehicle drive unit for realizing a modified example of the lubrication control device according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] A lubrication control device according to an embodiment of the present disclosure will be described with reference to the drawings. Note that the components in the following embodiments include those that are easily replaceable by those skilled in the art, or those that are substantially identical.

[0010] (Lubrication control device) The configuration of a lubrication control device according to an embodiment will be described with reference to Fig. 1 and Fig. 2. Fig. 1 shows a schematic configuration of a vehicle drive unit for realizing the lubrication control device according to the embodiment. Examples of vehicles on which the lubrication control device can be installed include hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs). The lubrication control device may also be installed in fuel cell electric vehicles (FCEVs), battery electric vehicles (BEVs), and the like.

[0011] The drive unit includes a motor 1, a motor chamber 2, a reduction / differential section 3, a gear chamber 4, a breather 5, a main oil passage 6, a first oil passage 7, a second oil passage 8, oil pumps 9 and 10, oil amount adjustment sections 11 and 12, an on-board sensor 13, and a calculation section 14.

[0012] The motor (MG) 1 is composed of, for example, a three-phase AC motor. The motor chamber 2 is for accommodating the motor 1. The reduction gear / differential gear 3 is connected to the rotating shaft of the motor 1. The gear chamber 4 is for accommodating the reduction gear / differential gear 3.

[0013] The breather 5 relieves pressure in the drive unit and is provided in the motor chamber 2 or the gear chamber 4. The main oil passage 6 is an oil passage for supplying oil pumped by oil pumps 9 and 10 to the first oil passage 7 and the second oil passage 8. The first oil passage 7 is an oil passage for supplying oil to the motor chamber 2. The second oil passage 8 is an oil passage for supplying oil to the gear chamber 4. The first oil passage 7 and the second oil passage 8 are connected to the main oil passage 6.

[0014] The oil pump 9 is for supplying oil from within the motor chamber 2 to the first oil passage 7. The oil pump 10 is for supplying oil from within the gear chamber 4 to the second oil passage 8. The oil pumps 9, 10 may be either mechanical or electric.

[0015] The oil amount adjusting unit 11 adjusts the amount of oil supplied to the motor chamber 2 through the first oil passage 7. The oil amount adjusting unit 12 adjusts the amount of oil supplied to the gear chamber 4 through the second oil passage 8. The oil amount adjusting units 11 and 12 adjust the amount of oil supplied to the motor chamber 2 and the gear chamber 4, respectively, depending on the motor rotation speed, gear rotation speed, lateral acceleration, oil temperature, etc. In doing so, the oil amount adjusting units 11 and 12 adjust the amount of oil based on an instruction from the calculation unit 14 (an instruction to adjust the amount of oil supplied).

[0016] The on-board sensors 13 are a group of sensors mounted on the vehicle, and examples of the on-board sensors 13 include an oil amount sensor, an oil temperature sensor, an acceleration sensor, a vehicle speed sensor, a steering angle sensor, an accelerator opening sensor, and a rotation speed sensor.

[0017] As shown in FIG. 2, the oil amount sensor detects the oil level in the motor chamber 2 and the gear chamber 4. The oil temperature sensor detects the oil temperature in the motor chamber 2 and the gear chamber 4. The acceleration sensor detects the lateral acceleration. The vehicle speed sensor detects the vehicle speed. The steering angle sensor detects the steering angle of the vehicle. The accelerator opening sensor detects the accelerator opening. The rotation speed sensor detects the motor rotation speed (MG rotation speed).

[0018] The calculation unit 14 is an electronic control unit (ECU) whose main components are a microcomputer including a central processing unit (CPU), read only memory (ROM), random access memory (RAM), and the like.

[0019] As shown in Fig. 2, calculation unit 14 calculates lateral acceleration based on one or more of vehicle speed, steering angle, and accelerator opening detected by on-board sensor 13. Calculation unit 14 also calculates gear rotation speed based on motor rotation speed. Calculation unit 14 also calculates the amount of oil distributed to motor chamber 2 and gear chamber 4 based on the oil level, oil temperature, vehicle acceleration, lateral acceleration, and gear rotation speed. Calculation unit 14 also instructs oil amount adjustment units 11 and 12 to adjust the amount of oil supplied to motor chamber 2 and gear chamber 4 based on the calculated amount of oil distributed.

[0020] 2, it is not essential to detect the oil level using an oil amount sensor. Also, it is sufficient to perform either the detection of lateral acceleration using an acceleration sensor or the calculation of lateral acceleration by calculation unit 14. Furthermore, the calculation of the oil distribution amount by calculation unit 14 may be performed by substituting into a physical formula, or may be performed by using, for example, an X-dimensional map to determine the distribution amount from oil temperature, lateral acceleration, motor rotation speed, gear rotation speed, etc.

[0021] Here, conventional drive units do not have oil amount adjusting sections 11, 12, and a communication hole is formed at position A in Figure 1 (in the wall separating the motor chamber 2 and gear chamber 4). In this conventional configuration, when lateral acceleration (lateral G) occurs due to the vehicle turning left or right, the oil level in the motor chamber and gear chamber tilts and is determined by the natural course of events, which increases the contact area between the oil and the motor rotor and gears in the reduction and differential sections.

[0022] In the conventional configuration, if the lateral acceleration or motor rotation speed remains above a certain level, oil foaming due to agitation of the oil or pressure changes within the drive unit can cause oil to spray out of the breather, which releases pressure to the outside (breather spraying). To avoid this, it is possible to set the breather at a higher position or to provide a breather chamber, but this comes at the cost of increasing the size of the drive unit.

[0023] 1, the lubrication control device according to the embodiment has a first oil passage 7 that supplies oil to the motor chamber 2 and a second oil passage 8 that supplies oil to the gear chamber 4. Then, oil amount adjusters 11, 12 adjust the amounts of oil supplied to the motor chamber 2 and the gear chamber 4, respectively, according to the motor rotation speed, gear rotation speed, lateral acceleration, oil temperature, etc., thereby creating a difference in oil level between the motor chamber 2 and the gear chamber 4.

[0024] For example, in the example shown in Fig. 1, when the oil supply rate through the main oil passage 6 is set to "10", the supply rate through the first oil passage 7 is set to "3", thereby lowering the oil level in the motor chamber 2 (see part C) below the oil level in the conventional configuration (see part B). Also, in the example shown in Fig. 1, when the oil supply rate through the main oil passage 6 is set to "10", the supply rate through the second oil passage 8 is set to "7", thereby raising the oil level in the gear chamber 4 (see part D) above the oil level in the conventional configuration (see B).

[0025] In this way, in the lubrication control device according to the embodiment, when lateral acceleration occurs in the vehicle, the ratio of oil supplied to the motor chamber 2 and the gear chamber 4 can be freely adjusted, thereby suppressing an increase in the contact area between the rotor of the motor 1 and the gears of the reduction / differential unit 3 and the oil. This makes it possible to suppress breather spray without increasing the size of the drive unit.

[0026] (Variation 1) A first modification of the lubrication control device according to the embodiment will now be described. While the lubrication control device shown in FIG. 1 is provided with two oil quantity adjusting units, only one oil quantity adjusting unit may be used. In this case, an oil quantity adjusting unit is provided on the route of the main oil passage 6, and a first oil passage 7 and a second oil passage 8 are branched from the position of the oil quantity adjusting unit and connected to the motor chamber 2 and the gear chamber 4, respectively. Furthermore, the calculation unit 14 issues an instruction to this single oil quantity adjusting unit to adjust the amount of oil supplied to the motor chamber 2 and the gear chamber 4. In this way, in the first modification of the lubrication control device according to the embodiment, by using only one oil quantity adjusting unit, the size of the drive unit can be made smaller.

[0027] (Variation 2) A second modification of the lubrication control device according to the embodiment will now be described. While the lubrication control device shown in FIG. 1 is provided with two oil pumps, only one oil pump may be used. In this case, for example, only oil pump 10 from the configuration of FIG. 1 is used. A third oil passage is provided below motor chamber 2 to return oil from within motor chamber 2 to oil pump 10, and an oil quantity adjuster 11 is provided in this third oil passage. Similarly, a fourth oil passage is provided below gear chamber 4 to return oil from within gear chamber 4 to oil pump 10, and an oil quantity adjuster 12 is provided in this fourth oil passage. Thus, in the second modification of the lubrication control device according to the embodiment, by using only one oil pump, the size of the drive unit can be further reduced and costs can be reduced.

[0028] (Variation 3) A third modification of the lubrication control device according to the embodiment will now be described. While the lubrication control device shown in FIG. 1 includes two oil pumps and two oil quantity adjustment units, only one oil pump and one oil quantity adjustment unit may be used. In this case, for example, only the oil pump 10 of the configuration shown in FIG. 1 is used. A third oil passage is provided below the motor chamber 2, returning oil from the motor chamber 2 to the oil pump 10. Similarly, a fourth oil passage is provided below the gear chamber 4, returning oil from the gear chamber 4 to the oil pump 10. An oil quantity adjustment unit is provided at the junction of the third and fourth oil passages. Thus, in the third modification of the lubrication control device according to the embodiment, by using only one oil pump and one oil quantity adjustment unit, the size of the drive unit can be further reduced, and costs can be reduced.

[0029] (Variation 4) A fourth modified example of the lubrication control device according to the embodiment will now be described. In the lubrication control device shown in Fig. 1, an example has been described in which the oil level in the motor chamber 2 is lowered compared to the conventional configuration and the oil level in the gear chamber 4 is raised compared to the conventional configuration, but how the oil level in each chamber is adjusted varies depending on the direction of lateral acceleration and the position of the breather 5.

[0030] For example, as shown in Figure 1, if lateral acceleration (left lateral G) occurs in the direction from the gear chamber 4 to the motor chamber 2 and the breather 5 is installed on the motor chamber 2 side, the oil level in the motor chamber 2 is lowered and the oil level in the gear chamber 4 is raised. In this case, the oil level slopes upward to the left.

[0031] Furthermore, when lateral acceleration (right lateral G) occurs in the direction from the motor chamber 2 to the gear chamber 4 and the breather 5 is provided on the motor chamber 2 side, the oil level in the motor chamber 2 is lowered and the oil level in the gear chamber 4 is raised, as in Figure 1. In this case, the slope of the oil level rises to the right, opposite to that in Figure 1.

[0032] Furthermore, when lateral acceleration (left lateral G) occurs in the direction from the gear chamber 4 to the motor chamber 2 and the breather 5 is provided on the gear chamber 4 side, the oil level in the motor chamber 2 is raised and the oil level in the gear chamber 4 is lowered. In this case, the oil level slopes upward to the left, as in Figure 1.

[0033] Furthermore, when lateral acceleration (right lateral G) occurs in the direction from the motor chamber 2 to the gear chamber 4 and the breather 5 is provided on the gear chamber 4 side, the oil level in the motor chamber 2 is increased and the oil level in the gear chamber 4 is decreased. In this case, the oil level slopes upward to the right, opposite to that in Figure 1.

[0034] (Variation 5) A fifth modified example of the lubrication control device according to the embodiment will be described with reference to Fig. 3. The lubrication control device shown in Fig. 1 uses an oil level sensor that detects the oil level, but there are cases where the vehicle is not equipped with an oil level sensor.

[0035] In this case, for example, only the oil pump 10 is used from the configuration in Figure 1. In addition, a third oil passage is provided below the motor chamber 2 to return the oil in the motor chamber 2 to the oil pump 10 side, and an oil amount adjustment unit 11 is provided in this third oil passage. Similarly, a fourth oil passage is provided below the gear chamber 4 to return the oil in the gear chamber 4 to the oil pump 10 side, and an oil amount adjustment unit 12 is provided in this fourth oil passage. In addition, strainers are provided at the starting ends of the third and fourth oil passages.

[0036] Furthermore, a communication hole is provided in the wall separating the motor chamber 2 and the gear chamber 4. This communication hole is provided at a height that ensures that the strainer intake port is immersed in the oil by the required amount even when the vehicle turns left or right and when the oil level difference between the motor chamber 2 and the gear chamber 4 is at its maximum.

[0037] For example, if the vehicle is not equipped with an oil level sensor, the amount of oil supplied cannot be adjusted according to the oil level, and the oil level in either the motor chamber 2 or the gear chamber 4 may become too low, which could cause air suction depending on the position of the strainer. On the other hand, in Modification 5 of the lubrication control device according to the embodiment, for example, oil in one chamber is scooped up, and the oil moves to the other chamber through the communication hole. This allows the oil level in each chamber to be maintained above a certain level, thereby suppressing air suction by the strainer.

[0038] (Variation 6) A sixth modification of the lubrication control device according to the embodiment will be described. In this modification, one oil amount adjusting unit and one strainer are used in addition to the configuration of the fifth modification. The configuration of the drive unit to which this modification is applied will be described below with reference to FIG.

[0039] The drive unit includes a motor 1, a motor chamber 2, a reduction / differential section 3, a gear chamber 4, a breather 5, a main oil passage 6, a first oil passage 7, a second oil passage 8, an oil pump 9, an oil amount adjusting section 11, an on-board sensor 13, a calculation section 14, a strainer 15, and a communication hole 16.

[0040] The oil pump 9 is connected to the main oil passage 6. The main oil passage 6 branches into a first oil passage 7 and a second oil passage 8. The oil amount adjusting unit 11 is provided at the point where the main oil passage 6 branches into the first oil passage 7 and the second oil passage 8. The strainer 15 is provided in the lower part of the motor chamber 2.

[0041] The communication hole 16 is provided in the wall separating the motor chamber 2 and the gear chamber 4. The communication hole 16 is provided at a height that ensures that the strainer intake port is immersed in the oil by the required amount even when the vehicle turns left or right and when the oil level difference between the motor chamber 2 and the gear chamber 4 is at its maximum.

[0042] For example, if an oil level sensor is not installed in the vehicle, the amount of oil supplied cannot be adjusted according to the oil level, which could lead to a concern that the oil level in the motor chamber 2 may become too low, causing air to be sucked into the strainer 15. On the other hand, in the sixth modification of the lubrication control device according to the embodiment, for example, oil in the gear chamber 4 is scooped up, and the oil moves to the motor chamber 2 through the communication hole 16. This makes it possible to maintain the oil level in the motor chamber 2 at a certain level or higher, thereby suppressing air from being sucked into the strainer 15. Furthermore, in the sixth modification of the lubrication control device according to the embodiment, by using only one oil pump, one oil amount adjuster, and one strainer, the size of the drive unit can be made smaller and costs can be reduced.

[0043] (Variation 7) A seventh modification of the lubrication control device according to the embodiment will now be described. In the lubrication control device shown in Fig. 1, after detecting or calculating the lateral acceleration, the amount of oil distributed to the motor chamber 2 and the gear chamber 4 is calculated, and an instruction to adjust the amount of oil supplied to the oil amount adjusters 11 and 12 is issued. However, the lateral acceleration may be predicted in advance.

[0044] In this case, calculation unit 14 predicts whether lateral acceleration will occur and the magnitude of the lateral acceleration that will occur based on information obtained from a GPS (Global Positioning System), a navigation system, etc. Next, calculation unit 14 calculates the amount of oil to be distributed to motor chamber 2 and gear chamber 4, and issues instructions to oil amount adjusters 11 and 12 to adjust the amount of oil supplied. Calculation unit 14 performs this series of processes before lateral acceleration occurs. Then, after calculating or detecting the actual lateral acceleration, calculation unit 14 feeds back the detected or calculated lateral acceleration to the calculation process for the amount of oil to be distributed.

[0045] In this way, in the seventh modification of the lubrication control device according to the embodiment, the lateral acceleration is predicted in advance and the amount of oil supplied is controlled before the lateral acceleration starts to be applied, thereby shortening the delay time due to the control. As a result, the oil level can be brought to an optimal state earlier, further reducing the risk of breather blowout.

[0046] In addition, in the seventh modification of the lubrication control device according to the embodiment, for example, data relating to the driver's normal driving speed and lateral acceleration may be stored in a storage medium installed inside the vehicle or an online storage medium and used to predict the lateral acceleration and vehicle speed. In this way, by using the data accumulated up to now to predict the lateral acceleration and vehicle speed, predictions can be made with high accuracy, resulting in more effective control.

[0047] In the lubrication control device according to the embodiment described above, even when lateral acceleration occurs in the vehicle, the amount of oil in the motor chamber 2 and the gear chamber 4 can be optimally controlled, thereby suppressing increased friction and insufficient lubrication. [Explanation of symbols]

[0048] 1 motor (MG) 2 Motor room 3 Reduction section / Differential section 4 Gear Room 5. Breather 6 Main oilway 7 First oil road 8 Second oilway 9,10 Oil pump (O / P) 11,12 Oil amount adjustment part 13 In-vehicle sensors 14 Arithmetic section 15 strainer 16 Communication hole

Claims

[Claim 1] a motor chamber that houses a motor; a gear chamber that houses a reduction gear unit and a differential unit connected to the motor; a first oil passage for supplying oil to the motor chamber; a second oil passage for supplying the oil to the gear chamber; an oil pump that supplies the oil to the first oil passage and the second oil passage; an oil amount adjusting unit that adjusts the amount of oil supplied to the motor chamber and the gear chamber in accordance with a motor rotation speed, a gear rotation speed, a lateral acceleration, and an oil temperature; A lubrication control device comprising:

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