JP7003906B2 - Lubricating oil supply device for differential devices - Google Patents

Description

The present invention relates to a lubricating oil supply device that supplies lubricating oil to a differential device provided in a driving force transmission system between a driving device and left and right wheels.

In a vehicle such as an automobile, a differential device that allows differential between the left and right wheels is provided in the driving force transmission system between the drive device and the left and right wheels. Since the differential contains a plurality of gears that mesh with each other, the differential is supplied with lubricating oil (oil) by a lubricating oil supply device. The flow rate of lubricating oil required to lubricate the differential device increases as the differential rotation speed of the left and right wheels increases. Therefore, for example, as described in Patent Document 1 below, a lubricating oil supply device configured to increase the amount of lubricating oil supplied to the differential device when the differential rotation speed becomes equal to or higher than the reference rotation speed is already known. Has been done.

The viscosity of the lubricating oil decreases as the oil temperature increases, and the lubricating oil is more easily supplied as the oil temperature increases. The following Patent Document 2 describes a lubricating oil supply device configured to change the rotation speed of a pump for supplying lubricating oil to a speed change mechanism according to an oil temperature.

Japanese Unexamined Patent Publication No. 2014-126874 Japanese Unexamined Patent Publication No. 2000-27992

[Problems to be solved by the invention]
In the conventional lubricating oil supply device described in Patent Document 1, the amount of lubricating oil supplied to the differential device is not changed by the oil temperature of the lubricating oil. Therefore, when the oil temperature of the lubricating oil is high and the viscosity is low, the amount of the lubricating oil supplied to the differential device becomes excessive, and it is difficult to improve the fuel efficiency of the vehicle. Therefore, it is conceivable to apply the configuration of changing the rotation speed of the pump according to the oil temperature described in Patent Document 2 to the conventional lubricating oil supply device described in Patent Document 1.

When the configurations described in Patent Documents 1 and 2 are combined, the storage device stores the relationship between the differential rotation speed of the left and right wheels and the oil temperature of the lubricating oil and the rotation speed of the pump, and the left and right wheels are stored. The pump rotation speed shall be determined based on both the differential rotation speed of the pump and the oil temperature of the lubricating oil. Therefore, the control load of the control device is higher than that of the lubricating oil supply device described in Patent Document 1, and the control cannot be simplified.

An object of the present invention is to appropriately control the work load of the pump device based on both the differential rotation speed of the left and right wheels and the oil temperature of the lubricating oil while avoiding an increase in the control load of the control device. Is.

[Means for Solving Problems and Effects of Invention]
According to the present invention, the differential device (18) provided in the drive force transmission system (16) between the drive device (12) and the left and right wheels (14L, 14R) is connected to the differential device (18) via the pump device (46). A supply device (22) that supplies the lubricating oil (20), a control device (24) that controls the supply device, and a differential rotation speed detection device (26) that detects the differential rotation speed (ΔVwlr) of the left and right wheels. And an oil temperature detecting device (28) for detecting the oil temperature (24) of the lubricating oil, and a lubricating oil supply device (10) for a differential device including the oil temperature detecting device (28) are provided.

The pump device (46) includes a pump and a drive unit for driving the pump, and the control device (24) determines that the detected differential rotation speed (ΔVwlr) is equal to or higher than the reference rotation speed (ΔVwo). The target work amount (Qt) of the pump device is calculated based on the differential rotation speed without comparing the detected oil temperature (Toil) and the reference oil temperature (Toilo), and the detected differential rotation speed is the reference. When the number of revolutions is less than the reference oil temperature, the target work of the pump device is such that when the detected oil temperature is above the reference oil temperature, the detected oil temperature is smaller than when the detected oil temperature is below the reference oil temperature. The amount is calculated, and the drive unit of the pump device is controlled so that the work amount (Q) of the pump device supplied to the differential device (18) becomes the target work amount (Qt).

As will be described in detail later, the amount of work required for the pump device required to properly lubricate the differential device with lubricating oil increases as the differential rotation speed of the left and right wheels increases. The rate of increase in the required work of the pump device with the increase in the differential rotation speed is large in the region where the differential rotation speed is large, but small in the region where the differential rotation speed is small. Further, the required work amount of the pump device becomes smaller as the oil temperature of the lubricating oil is higher. The difference in the required work of the pump device when the oil temperature of the lubricating oil is high and low is large in the region where the differential rotation speed is small, but the higher the differential rotation speed is in the region where the differential rotation speed is high. It gets smaller.

Therefore, the target work amount of the pump device for properly lubricating the differential device with the lubricating oil may be calculated based only on the differential rotation speed in the region where the differential rotation speed is large. On the other hand, in the region where the differential rotation speed is small, it is preferable that the target work amount of the pump device is calculated so as to be smaller as the oil temperature of the lubricating oil is higher.

According to the above configuration, when the differential rotation speed of the left and right wheels is equal to or higher than the reference rotation speed, the pump device is based on the differential rotation speed without comparing the oil temperature of the lubricating oil with the reference oil temperature. The target workload of is calculated. Therefore, the target work amount of the pump device can be calculated without considering the oil temperature of the lubricating oil, and the work amount of the pump device can be easily controlled. Therefore, it is necessary to avoid an increase in the control load of the control device. Can be done.

Further, according to the above configuration, when the differential rotation speed is less than the reference rotation speed, when the oil temperature is equal to or higher than the reference oil temperature, the oil temperature is lower than the reference oil temperature, as compared with the case where the oil temperature is lower than the reference oil temperature. The target work amount of the pump device is calculated based on both the differential rotation speed and the oil temperature of the lubricating oil so as to be small. Therefore, when the differential rotation speed is less than the reference rotation speed, the target work amount of the pump device is calculated to an appropriate value as compared with the case where the oil temperature is not taken into consideration, and the work amount of the pump device is appropriately controlled. can do.

In the above description, in order to help the understanding of the present invention, the reference numerals used in the embodiments are added in parentheses to the configurations of the invention corresponding to the embodiments described later. However, each component of the present invention is not limited to the component of the embodiment corresponding to the reference numeral attached in parentheses. Other objects, other features and accompanying advantages of the invention will be readily understood from the description of embodiments of the invention described with reference to the following drawings.

It is a schematic block diagram which shows the embodiment of the lubricating oil supply device for a differential device by this invention. It is a flowchart which shows the control routine of the work amount Q of a pump device in 1st Embodiment. It is a flowchart which shows the control routine of the work amount Q of a pump device in 2nd Embodiment. It is a map for calculating the target work Qt of a pump device based on the differential rotation speed ΔVwlr and the oil temperature Toil of a lubricating oil. It is a graph which shows the relationship between the differential rotation speed ΔVwlr, the oil temperature Toil of a lubricating oil, and the required work amount Qreq of a pump device.

[Embodiment]
Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying figures.

The lubricating oil supply device 10 according to the embodiment of the present invention supplies the lubricating oil 20 to the differential device 18 provided in the driving force transmission system 16 between the drive device 12 and the left and right wheels 14L and 14R. 22 and an electronic control device 24 as a control device for controlling the supply device. The lubricating oil supply device 10 further includes a differential rotation speed detecting device 26 that detects the differential rotation speed Vwd of the left and right wheels, and a temperature sensor 28 as an oil temperature detecting device that detects the oil temperature Toil of the lubricating oil. Includes.

The drive device 12 may be any drive device known in the art, such as an internal combustion engine, a motor, or a hybrid system. The driving force transmission system 16 is a speed reducing device 30 that increases the driving force of the driving device 12 by deceleration and transmits the driving force to the differential device 18, and a drive that transmits the driving force from the differential device 18 to the left and right wheels 14L and 14R, respectively. Includes shafts 32L and 32R. Although not shown in FIG. 1, the speed reducer 30 may include an unauthorized transmission such as a gear type transmission or a belt type transmission.

The differential device 18 is a dry sump type differential gear device, and includes a ring gear 34, a pair of side gears 36L and 36R, and a pair of pinion gears 38 that mesh with the side gears. The ring gear 34 is integrally connected to the casing 40 and is driven by the output gear 42 of the speed reducer 30. The side gears 36L and 36R and the pinion gear 38 are rotatably supported by the casing 40. The side gears 36L and 36R are integrally connected to the inner ends of the drive shafts 32L and 32R, respectively.

The supply device 22 is a pump device 46 that sucks up the lubricating oil 20 stored in the oil pan 44 and discharges the high-pressure lubricating oil, and a conduit 48 that guides the lubricating oil discharged by the pump device to the differential device 18 and the speed reducing device 30. And include. The conduit 48 distributes the lubricating oil discharged by the pump device at a constant flow rate ratio and guides the lubricating oil to the differential device 18 and the speed reducing device 30. The lubricating oil supplied to the differential device 18 and the speed reducing device 30 and after lubricating their gears and the like is returned to the oil pan 44 by a return conduit (not shown in FIG. 1).

Although not shown in detail in FIG. 1, the pump device 46 includes a pump and a drive unit for driving the pump, and the work load of the pump device is changed by controlling the drive unit by the electronic control device 24. It is designed to do. For example, the pump is a variable capacity pump driven by an engine or the like, and the work load of the pump device changes by controlling the opening and closing of the solenoid valve as the driving unit. Further, the pump is a constant capacity pump driven by an electric motor, and the work amount of the pump device may be changed by controlling the output of the electric motor.

The differential rotation speed detection device 26 includes wheel speed sensors 50L and 50R that detect the wheel speeds Vwl and Vwr of the left and right wheels 14L and 14R. The signal indicating the wheel speeds Vwl and Vwr is input to the electronic control device 24, and the electronic control device 24 calculates the differential rotation speed ΔVwlr of the left and right wheels 14L and 14R as the absolute value of the difference Vwl-Vwr between the wheel speeds Vwl and Vwr. do. Therefore, the electronic control device 24 cooperates with the wheel speed sensors 50L and 50R to form the differential rotation speed detection device 26.

In the illustrated embodiment, the temperature sensor 28 detects the oil temperature Toil of the lubricating oil 20 stored in the oil pan 44, and a signal indicating the oil temperature Toil is input to the electronic control device 24. The temperature sensor 28 may be adapted to detect the oil temperature of the lubricating oil sucked by the pump of the pump device 46 or the lubricating oil discharged by the pump.

The electronic control device 24 includes a CPU, a ROM, a RAM, and an input / output port device, which are connected to each other by a bidirectional common bus. The CPU of the electronic control device 24 calculates the target work Qt of the pump device 46 for the supply device 22 to supply the lubricating oil to the differential device 18 according to the flowchart shown in FIG. 2 or FIG. The drive unit of the pump device 46 is controlled so that the work amount Q of the pump device 46 becomes the target work amount Qt. The ROM of the electronic control device 24 stores a control routine corresponding to the flowchart and a map described later.

[First Embodiment]
FIG. 2 is a flowchart showing a control routine of the work amount Q of the pump device according to the first embodiment. The control of the workload Q according to the flowchart shown in FIG. 2 is repeatedly executed at predetermined time intervals when the ignition switch (not shown in the figure) is on. This also applies to the control of the work amount Q by the flowchart shown in FIG. 3 described later.

First, in step 10, a signal indicating the wheel speeds Vwl and Vwr detected by the wheel speed sensors 50L and 50R and a signal indicating the oil temperature Toil detected by the temperature sensor 28 are read.

In step 20, the differential rotation speed ΔVwlr of the left and right wheels 14L and 14R is calculated as the absolute value of the difference Vwl-Vwr between the wheel speeds Vwl and Vwr.

In step 30, the pump device 46 for the supply device 22 to supply the lubricating oil 20 to the differential device 18 by referring to the map shown by the solid line in FIG. 4 based on the differential rotation speed ΔVwlr. The target work amount Qt of is calculated. As shown by the solid line in FIG. 4, when the differential rotation speed ΔVwlr is equal to or higher than the reference rotation speed ΔVwo (positive constant), the larger the differential rotation speed ΔVwlr is, the larger the target work amount Qt is. When the differential rotation speed ΔVwlr is less than the reference rotation speed ΔVwo, it is calculated to a constant value Qtc (positive constant) regardless of the differential rotation speed ΔVwlr.

In step 40, it is determined whether or not the differential rotation speed ΔVwlr is equal to or higher than the reference rotation speed ΔVwo. When the affirmative determination is made, the control of the workload Q proceeds to step 80, and when the negative determination is made, the control of the workload Q proceeds to step 50.

In step 50, it is determined whether or not the oil temperature Toil of the lubricating oil 20 is equal to or higher than the reference oil temperature Toilo (positive constant). When the negative determination is made, the control of the workload Q proceeds to step 80, and when the positive determination is made, the control of the workload Q proceeds to step 60.

In step 60, the supply device 22 supplies the lubricating oil 20 to the differential device 18 by referring to the map shown by the broken line or the alternate long and short dash line in FIG. 4 based on the differential rotation speed ΔVwlr. The target work amount Qt of the pump device 46 is calculated. As can be seen from the comparison between the solid line in FIG. 4 and the broken line and the alternate long and short dash line, the target work Qt calculated in this step is smaller than the constant value Qtc.

In step 80, the drive unit of the pump device 46 of the supply device 22 is controlled so that the work amount Q of the pump device 46 becomes the target work amount Qt, whereby the differential device 18 and the speed reducer 30 become the lubricating oil 20. Is lubricated.

[Second embodiment]
FIG. 3 is a flowchart showing a control routine of the work amount Q of the pump device according to the second embodiment. In FIG. 3, the same step as the step shown in FIG. 2 is assigned the same step number as the step number assigned in FIG.

In the second embodiment, step 30 in the first embodiment is not executed, and when step 20 is completed, the control of the workload Q proceeds to step 40. Further, when the affirmative determination is made in step 40 or the negative determination is made in step 50, the control of the work amount Q proceeds to step 70. In step 70, the target of the pump device 46 is targeted by referring to the map shown by the solid line in FIG. 4 based on the differential rotation speed ΔVwlr in the same manner as in step 30 in the first embodiment. The workload Qt is calculated.

As can be seen from the comparison between FIG. 3 and FIG. 2, the other steps of the second embodiment are performed in the same manner as in the first embodiment described above, whereby the differential device 18 and the speed reducer 30 are lubricated. Lubricated at 20.

[Actions and effects of the first and second embodiments]
FIG. 5 shows the required work amount Qreq of the pump device required to properly lubricate the differential device 18 with the lubricating oil 20, the differential rotation speed ΔVwlr of the left and right wheels, and the oil temperature Toil of the lubricating oil. There is a relationship as shown. That is, the required work amount Qreq increases as the differential rotation speed ΔVwlr increases. The rate of increase in the required work of the pump device with the increase in the differential rotation speed is large in the region where the differential rotation speed is large, but small in the region where the differential rotation speed is small. Further, the required work amount of the pump device becomes smaller as the oil temperature Toil of the lubricating oil is higher. The difference in the required work of the pump device when the oil temperature of the lubricating oil is high and low is large in the region where the differential rotation speed is small, but the higher the differential rotation speed is in the region where the differential rotation speed is high. It gets smaller.

Therefore, the target work amount Qt of the pump device for properly lubricating the differential device 18 with the lubricating oil 20 is limited to the differential rotation speed only in the region where the differential rotation speed ΔVwlr is larger than the reference rotation speed ΔVwo. It may be calculated based on. On the other hand, in a small region where the differential rotation speed is less than the reference rotation speed ΔVwo, it is preferable that the target work amount Qt of the pump device is calculated so as to be smaller as the oil temperature Toil of the lubricating oil is higher.

According to the first and second embodiments described above, in the target work Qt of the pump device, the oil temperature Toil of the lubricating oil is taken into consideration in the region where the differential rotation speed ΔVwlr is equal to or higher than the reference rotation speed ΔVwo. It is calculated by referring to the map shown by the solid line in FIG. 4 based on the differential rotation speed ΔVwlr. Therefore, the target work amount of the pump device can be calculated without considering the oil temperature of the lubricating oil, and the work amount of the pump device can be easily controlled. Therefore, it is necessary to avoid an increase in the control load of the control device. Can be done.

Further, according to the first and second embodiments described above, in the region where the differential rotation speed ΔVwlr is less than the reference rotation speed ΔVwo, the dashed line or the alternate long and short dash line is shown in FIG. 4 based on the differential rotation speed ΔVwlr. By referring to the map, the target work Qt of the pump device is calculated so that the higher the oil temperature Toil, the smaller the target work Qt. Therefore, when the differential rotation speed is less than the reference rotation speed, the target work amount of the pump device is calculated to an appropriate value as compared with the case where the oil temperature is not taken into consideration, and the work amount of the pump device is appropriately controlled. can do.

Although the present invention has been described in detail above with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. Will be obvious to those skilled in the art.

For example, in the first and second embodiments described above, when the differential rotation speed ΔVwlr is less than the reference rotation speed ΔVwo, the target work Qt of the pump device 46 may be a constant value Qtc. In that case, the target work Qt may be set to Qtc without reference to the map. Further, the target work Qt in the region where the differential rotation speed ΔVwlr is less than the reference rotation speed ΔVwo gradually increases as the differential rotation speed ΔVwlr increases, as shown by the alternate long and short dash line in FIG. May be set.

Further, in the first and second embodiments described above, when the oil temperature Toil of the lubricating oil 20 is equal to or higher than the reference oil temperature Toilo, in step 60, a broken line or a dotted line or one point in FIG. 4 based on the differential rotation speed ΔVwlr. By referring to the map shown by the chain line, the target work Qt of the pump device 46 is calculated to gradually increase as the differential rotation speed ΔVwlr increases. However, when the oil temperature Toil of the lubricating oil is equal to or higher than the reference oil temperature Toilo, the target work amount Qt is set to a constant value smaller than Qtc without reference to the map based on the differential rotation speed ΔVwlr. May be good.

Further, in the first and second embodiments described above, the map shown in FIG. 4 is a straight line, and the target work Qt of the pump device 46 has a constant rate of change with respect to the differential rotation speed ΔVwlr. ing. However, at least a part of the map of the target work Qt has a downwardly convex curve corresponding to FIG. 5 so that the rate of change of the target work Qt gradually increases with the increase of the differential rotation speed ΔVwlr. May be good.

Further, in the first embodiment described above, the differential rotation speed detecting device 26 for detecting the differential rotation speed Vwd of the left and right wheels is a wheel speed for detecting the wheel speeds Vwl and Vwr of the left and right wheels 14L and 14R. Includes sensors 50L and 50R. However, signals indicating wheel speeds Vwl and Vwr may be input from other control devices of the vehicle.

Further, in the second embodiment described above, the supply device 22 supplies the lubricating oil to the differential device 18 and the speed reduction device 30, but the speed reduction device 30 is supplied by a supply device other than the supply device 22. Lubricating oil may be supplied.

10 ... Lubricating oil supply device, 12 ... Drive device, 14L, 14R ... Wheels, 16 ... Driving force transmission system, 18 ... Differential device, 20 ... Lubricating oil, 22 ... Supply device, 24 ... Electronic control device, 26 ... Difference Dynamic rotation speed detection device, 28 ... temperature sensor, 30 ... deceleration device, 46 ... pump device, 50L, 50R ... wheel speed sensor

Claims (1)

A supply device that supplies lubricating oil to a differential device provided in a drive force transmission system between the drive device and the left and right wheels via a pump device, a control device that controls the supply device, and the left and right wheels. In a lubricating oil supply device for a differential device, which includes a differential rotation speed detecting device for detecting the differential rotation speed of the above, an oil temperature detecting device for detecting the oil temperature of the lubricating oil, and a lubricating oil supply device for the differential device.
The pump device includes a pump and a drive unit for driving the pump.
The control device is
When the detected differential rotation speed is equal to or higher than the reference rotation speed, the target work amount of the pump device is calculated based on the differential rotation speed without comparing the detected oil temperature with the reference oil temperature.
When the detected differential rotation speed is less than the reference rotation speed, when the detected oil temperature is equal to or higher than the reference oil temperature, the detected oil temperature is lower than the reference oil temperature. , Calculate the target work of the pump device so that it becomes smaller,
A lubricating oil supply device for a differential device configured to control a drive unit of the pump device so that the work load of the pump device becomes a target work load.

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