Method for operating an oil circuit, in particular for a vehicle

Abstract

A method for operating an oil circuit for a vehicle, the oil circuit being configured to supply oil to an internal combustion engine, wherein the oil circuit includes an oil cooler, and wherein at least one temperature sensor measures the temperature of the oil flowing through the oil circuit, downstream of the oil cooler and upstream of the internal combustion engine, the temperature sensor being connected for signaling purposes to a regulating and/or control device, includes: controlling and/or regulating, by the regulating and/or control device, the temperature of the oil flowing through the oil circuit, such that the temperature measured by the temperature sensor has a defined target temperature value; and setting and/or adjusting, by the regulating and/or control device, as a function of a drive power of the internal combustion engine, the defined target temperature value so as to reduce fuel consumption of the internal combustion engine.

Claims

1. A method for operating an oil circuit (5) for a vehicle, the oil circuit (5) being configured to supply oil (8) to an internal combustion engine (7), wherein the oil circuit (5) includes an oil cooler (15), configured to cool the oil (8) flowing through the oil circuit (5), and wherein at least one temperature sensor (39) is provided, the temperature sensor (39) being configured to measure the temperature of the oil (8) flowing through the oil circuit (5), downstream of the oil cooler (15) and upstream of the internal combustion engine (7), the temperature sensor (39) being connected for signaling purposes to a regulating and/or control device (13, 35), the method comprising: controlling and/or regulating, by the regulating and/or control device (13, 35), the temperature of the oil (8) flowing through the oil circuit (5), such that the temperature measured by the temperature sensor (39) has a defined target temperature value (TSoll); and setting and/or adjusting, by the regulating and/or control device (11, 13, 43, 35), as a function of a drive power (PA) of the internal combustion engine (7), the defined target temperature value (TSoll) so as to reduce fuel consumption of the internal combustion engine (7), wherein the regulating and/or control device (13, 35) is connected for signaling purposes to a prediction device (47), by which the expected drive power (PA) of the internal combustion engine (7) in a segment of the route ahead of a vehicle (1) having the internal combustion engine (7) can be determined, the method further comprising: setting and/or adjusting the defined target temperature value (TSoll), chronologically prior to reaching the segment of the route ahead of the vehicle (1), by the regulating and/or control device (13, 35) as a function of the expected drive power (PA) of the internal combustion engine (7) determined by the prediction device (47).

2. The method according to claim 1, further comprising: if the drive power (PA) of the internal combustion engine (7) exceeds a defined drive power value (PA, def.), setting a first temperature value (T1) as the defined target temperature value (TSoll); and if the drive power (PA) of the internal combustion engine does not exceed the defined drive power value (PA, def.), setting a second temperature value (T2), higher than the first temperature value (T1), as the defined target temperature value (TSoll).

3. The method according to claim 1, further comprising: in a full load mode of the internal combustion engine (7) and/or in a partial load mode of the internal combustion engine (7) in an upper partial load region, setting a temperature value of 85 C. to 100 C., as the defined target temperature value (TSoll).

4. The method according to claim 1, further comprising: in a partial load mode of the internal combustion engine (7) in a lower and/or middle partial load region, setting a temperature value of 105 C. to 120 C. as the defined target temperature value (TSoll).

5. The method according to claim 1, wherein the oil circuit (5) further includes at least one bypass channel (19), by which at least a part of the oil (8) flowing through the oil circuit (5) can bypass the oil cooler (15), and wherein the regulating and/or control device (13, 35) includes an actuating device (13) configured to control the oil temperature of the oil circuit (5), the method further comprising: setting and/or adjusting, by the actuating device (13), the amount of oil (8) flowing through the bypass channel (19) and the amount of oil (8) passed via the oil cooler (15); and measuring, by the temperature sensor (39), the temperature of the oil (8) flowing through the oil circuit (5) downstream of an oil outlet (25) of the bypass channel (19) and upstream of the internal combustion engine (7) when looking in the direction of flow of the oil.

6. The method according to claim 5, wherein the actuating device (13) includes at least one regulated and/or controlled directional control valve.

7. The method according to claim 6, wherein a coolant circuit (41) is provided, by which the internal combustion engine (7) and the oil circuit (5) can be cooled by a coolant, wherein in the event of a cold start of the internal combustion engine (7) all the oil (8) is passed via the oil cooler (15) by the actuating device (13).

8. The method according to claim 1, wherein the oil circuit (5) includes at least one oil pump (11), by which the oil (8) is transported through the oil circuit (5), wherein the oil pump (11) is regulated and/or controlled by the regulating and/or control device (13, 35) for controlling the oil temperature of the oil circuit (5).

9. The method according to claim 1, wherein a coolant circuit (41) is provided, by which the internal combustion engine (7) and the oil circuit (5) can be cooled by a coolant, wherein for controlling the oil temperature of the oil circuit (5) at least one component of the coolant circuit (41) that influences the cooling of the oil circuit (5) is regulated and/or controlled by the regulating and/or control device (13, 35).

10. The method according to claim 1, wherein the prediction device (47) includes a weight determination device (49), by which the weight of the vehicle (1) is determined, and/or the prediction device (47) includes a gradient determination device (51), by which the gradient of the segment of the route ahead is determined.

11. The method according to claim 1, further comprising setting and/or adjusting, by the regulating and/or control device (13, 35), the defined target temperature value (TSoll) as a function of a current viscosity of the oil (8).

12. The method according to claim 11, wherein a viscosity measuring device (27, 31, 33, 37) is provided that is connected for signaling purposes to the regulating and/or control device (13, 35), the viscosity measuring device (27, 31, 33, 37) being configured to measure the current viscosity of the oil (8) flowing through the oil circuit (5), and/or an input device (36) is provided that is connected for signaling purposes to the regulating and/or control device (13, 35) and that can be operated by a person, by which the viscosity class and/or the HTHS characteristic of the oil (8) are input.

13. A vehicle configured to perform the method according to claim 1.

14. The method according to claim 1, wherein the drive power (PA), comprises at least one selected from the group consisting of: the drive torque and the drive revolution rate.

15. The method according to claim 1, further comprising: in a full load mode of the internal combustion engine (7) and/or in a partial load mode of the internal combustion engine (7) in an upper partial load region, setting a temperature value of 85 C. to 95 C., as the defined target temperature value (TSoll).

16. The method according to claim 1, further comprising: in a partial load mode of the internal combustion engine (7) in a lower and/or middle partial load region, setting a temperature value of 110 C. to 120 C. as the defined target temperature value (TSoll).

17. A device for a vehicle, comprising: an oil circuit (5) configured to supply an internal combustion engine (7) with oil (8), the oil circuit (5) comprising an oil cooler (15) configured to cool the oil (8) flowing through the oil circuit (5); a temperature sensor (39) configured to measure the temperature of the oil (8) flowing through the oil circuit (5) downstream of the oil cooler (15) and upstream of the internal combustion engine (7) in a direction of flow of oil; and a regulating and/or control device (13, 35) to which the temperature sensor (39) is connected for signaling purposes, the regulating and/or control device (13, 35) being configured to: control and/or regulate the temperature of the oil (8) flowing through the oil circuit (5) such that the temperature measured by the temperature sensor (39) has a defined target temperature value (TSoll), and set and/or adjust the defined target temperature value (TSoll) as a function of the drive power (PA) of the internal combustion engine (7) so as to reduce fuel consumption of the internal combustion engine (7), wherein the regulating and/or control device (13, 35) is connected for signaling purposes to a prediction device (47), by which the expected drive power (PA) of the internal combustion engine (7) in a segment of the route ahead of a vehicle (1) having the internal combustion engine (7) can be determined, the regulating and/or control device (13, 35) being further configured to: set and/or adjust the defined target temperature value (TSoll), chronologically prior to reaching the segment of the route ahead of the vehicle (1), by the regulating and/or control device (13, 35) as a function of the expected drive power (PA) of the internal combustion engine (7) determined by the prediction device (47).

18. A vehicle having a device according to claim 17.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention and the advantageous configurations and/or developments thereof as well as the advantages thereof are described in detail below using figures only by way of example.

(2) In the figures:

(3) FIG. 1 shows a side view of a vehicle with the device according to the invention;

(4) FIG. 2 shows a schematic representation, using which the design of the device is described; and

(5) FIG. 3 shows a flow chart representation, using which the procedure according to the invention is described.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(6) In FIG. 1 a vehicle 1, here by way of example in the form of a truck, with a device 3 according to the invention (FIG. 2) is shown. The design of the device 3 is described in detail below using FIG. 2:

(7) As is shown in FIG. 2, the device 3 comprises an oil circuit 5, by which an internal combustion engine 7, indicated in FIG. 2 with dashed lines, is supplied with oil 8. The oil circuit 5 comprises here by way of example an oil sump 9, an oil pump 11, a directional control valve 13, an oil cooler 15 and a main channel 17 when looking in the direction of flow of the oil. By the oil pump 11, the oil 8 that is collected in the oil sump 9 is sucked in and transported in the further oil circuit 5. The directional control valve 13, here by way of example in the form of a 3/2 directional control valve, forms an actuator, by which the amount of oil 8 that is passed by the oil cooler 15 and the amount of oil 8 flowing through a bypass channel 19 of the oil circuit 5 can be set or adjusted. By way of example, the oil circuit 5 branches here into the bypass channel 19 and into an oil cooler channel 23 at a branching region 21 disposed upstream of the oil cooler 15. The bypass channel 19 and the oil cooler channel 23 are re-joined in a joining region 25 disposed downstream of the oil cooler 15 when looking in the direction of flow of the oil. The branching region 21 is formed by the directional control valve 13 here by way of example. The main channel 17 of the oil circuit 5 runs downstream of the joining region 25 here. The internal combustion engine 7, the oil pump 11 and the directional control valve 13 are also connected for signaling purposes to a control unit 35 here, by which the oil pump 11 and the directional control valve 13 are controlled.

(8) According to FIG. 2, the device 3 also comprises, by way of example, a pressure sensor 37, by which the pressure of the oil 8 flowing through the oil circuit 5 can be measured in or on the main channel 17 of the oil circuit 5. In addition, the device 3 comprises a temperature sensor 39, by which the temperature of the oil 6 flowing through the oil circuit 5 can be measured in or on the main channel 17 of the oil circuit 5. The pressure sensor 37 and the temperature sensor 39 are also connected to the control unit 35 for signaling purposes.

(9) As is further shown in FIG. 2, the vehicle 1 comprises a temperature sensor 27, by which the temperature of the oil 8 of the oil circuit 5 collected in the oil sump 9 can be measured. Furthermore, the device 3 also comprises a pressure sensor 31, by which the pressure of the oil 8 flowing through the oil circuit 5 can be measured downstream of the oil pump 11 and upstream of the directional control valve 13 when looking in the direction of flow of the oil. Furthermore, the device also comprises, by way of example, a volumetric flow sensor 33, by which the volumetric flow of the oil 8 flowing through the oil circuit 5 can be measured downstream of the oil pump 11 and upstream of the directional control valve 13 when looking in the direction of flow of the oil. The temperature sensor 27, the pressure sensor 31 and the volumetric flow sensor 33 are connected to the control unit 35 for signaling purposes. The current viscosity of the oil 8 flowing through the oil circuit 5 downstream of the internal combustion engine 7 and upstream of the directional control valve 21 when looking in the direction of flow of the oil can be calculated by the control unit 35 from the temperature measured by the temperature sensor 27, the pressures measured by the pressure sensors 31, 37 and the volumetric flow measured by the volumetric flow sensor 33. The temperature sensor 27, the pressure sensors 31, 37, the volumetric flow sensor 33 and the control unit 35 thus form a viscosity measuring device. Alternatively, the current viscosity of the oil 8 could, for example, also be calculated from the temperature measured by the temperature sensor 27, the pressures measured by the pressure sensors 31, 37 and the revolution rate of the internal combustion engine 7.

(10) Alternatively and/or in addition to the viscosity measuring device, the device 3 could also include an input device 36 that is indicated in FIG. 2 with dashed lines and that can be operated by a person, by which the viscosity class and/or the HTHS characteristic of the oil 8 that is currently being used can be input. Using the information, the current viscosity of the oil can also be determined.

(11) As is also apparent from FIG. 2, the device 3 also comprises here by way of example a coolant circuit 41 that is partly shown in FIG. 2, by which the internal combustion engine 7 and the oil circuit 5 or the oil 8 flowing through the oil circuit 5 can be cooled by a coolant. The coolant circuit 41 comprises here by way of example a coolant pump 43, the oil cooler 15 as a heat absorbing heat exchanger and the internal combustion engine 7 when looking in the direction of flow of the coolant. The coolant pump 43 is here by way of example also connected to the control unit 35 for signaling purposes and is controlled by the control unit 35 as a function of a coolant temperature measured by a temperature sensor 45. The temperature of the coolant flowing through the coolant circuit 41 is measured here by way of example by the temperature sensor 45 downstream of the coolant transporting device 43 and upstream of the oil cooler 15.

(12) The directional control valve 13, the oil pump 15 and the coolant pump 43 are controlled or regulated by the control unit 35 such that the oil temperature measured by the temperature sensor 39 has a defined target temperature value. The target temperature value is set and/or adjusted by the control unit 35 here by way of example as a function of the drive power of the internal combustion engine 7 and the current viscosity of the oil 8 that is determined by the control unit 35.

(13) According to FIG. 3, the target temperature value is set here by way of example by the control unit 35 such that if the drive power P.sub.A of the internal combustion engine 7 exceeds a defined drive power value P.sub.A, def., a first temperature value T.sub.1 is set as the target temperature value T.sub.soll. If the drive power P.sub.A of the internal combustion engine 7 does not exceed the defined drive power value P.sub.A, def., a second temperature value T.sub.2 that is greater than the first temperature value T.sub.1 is set as the target temperature value T.sub.soll by the control unit 35. In this way the viscosity of the oil 8 flowing through the oil circuit 5 is always held as low as possible and hence the fuel consumption of the internal combustion engine 7 is reduced.

(14) Furthermore, the device 3 also comprises here an optional prediction device 47, by which the expected drive power of the internal combustion engine 7 on a segment of the route ahead of the vehicle 1 can be determined. The target temperature value can then be set and/or adjusted here by the control unit 35 chronologically prior to reaching the segment of route ahead as a function of the expected drive power of the internal combustion engine 7 that is determined by the prediction device 47. The prediction device 47 comprises here by way of example a weight determination device, by which the weight of the vehicle can be determined. In addition, the prediction device 47 also comprises here by way of example a gradient determination device 51, by which the gradient of the segment of the route ahead can be determined. In this case, the gradient of the segment of the route ahead can be determined for example by determining the position of the vehicle on the route thereof in combination with gradient data from a digital road map.

(15) Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.