DESC:FIELD OF THE INVENTION
The invention relates to an oil temperature management system and in particular, relates to an oil temperature management system for vehicles.

BACKGROUND

Generally, recovery vehicles, i.e., a vehicle assigned with the task of towing other vehicles, that operate in extreme weather conditions, for example, -20 °C to +55 °C, are capable of handling variable flows of hydraulic oil. For example, such recovery vehicles may handle flows in the range of 20 ltr/min to 260 ltr/min. To carry out the towing operation, a recovery vehicle may be provided with a plurality of recovery aggregates, such as a main winch, an auxiliary winch, a crane, a dozer, and a suspension locking.
All the above aggregates, as would be known, are operated hydraulically using a hydraulic system that uses oil. It is desirable that consistent oil performance characteristics be maintained, even when the hydraulic recovery aggregate is operated in high ambient temperature conditions or low ambient temperature conditions. Generally during operation of a hydraulic aggregate 10-15% of input energy will be rejected and converted to thermal energy. This energy will further increase the temperature of oil for every cycle of operation. Any increase in the oil temperature will have an adverse effect on the viscosity of hydraulic oil, which in turn would affect the performance of the hydraulic aggregate. Generally, hydraulic aggregates will be operated in an ambient temperature range of -20 °C to +55 °C; however, the given temperature ranges may very well be different for any peculiar application. In abrupt operating conditions, higher oil temperature would cause frequent seal failure which results in frequent maintenance, servicing and replacement of spares.
Conventional hydraulic oil temperature management system implementation includes the operation of the hydraulic aggregates with excess oil quantity in the hydraulic tank to balance the temperature rise in the hydraulic tank. Additionally, the hydraulic tanks would be sized in multiples of the maximum flow rate to compensate for oil temperature balancing. The aforementioned sizing scheme of the hydraulic tanks results in an unwanted increase in overall system weight, which is undesirable.
Therefore, there is a need for intelligent hydraulic oil temperature management system for the vehicle that does not suffer from aforementioned deficiencies and work efficiently under extreme hostile environment.

SUMMARY
This summary is provided to introduce a selection of concepts, in a simplified format, that are further described in the detailed description of the invention. This summary is neither intended to identify key or essential inventive concepts of the invention and nor is it intended for determining the scope of the invention.
In an embodiment of the present subject matter, a system for controlling oil temperature in hydraulic tanks is disclosed. The system comprises a sensor to measure a temperature of oil stored in a hydraulic tank. The system further comprises a controller for obtaining the measured temperature and comparing the measured temperature with a set of threshold temperatures. The set of threshold temperatures comprises at least a first threshold temperature and a second threshold temperature. If the measured temperature is lower than the first threshold temperature, the controller activates a heating unit to cause an increase in the temperature of the hydraulic tanks. If the measured temperature is higher than the second threshold temperature, the controller activates a cooling unit to cause a decrease in the temperature of the hydraulic tank.
In another example embodiment, a method of controlling oil temperature in hydraulic tanks, the method comprises, measuring a temperature of oil stored in a hydraulic tank by a sensor. The method further comprises comparing the measured temperature with a set of threshold temperatures, wherein the set of threshold temperatures comprises at least a first threshold temperature and a second threshold temperature. The method further comprises activating one of a heating unit and a cooling unit based on the comparing. Herein the heating unit is coupled to the hydraulic tank and the cooling unit is coupled to the hydraulic tank. Furthermore, the heating unit is activated to cause an increase in temperature when the measured temperature is lower than the first threshold temperature and the cooling unit is activated to cause a decrease in the temperature when the measured temperature is greater than the second threshold temperature.
To further clarify the advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
Figure 1 illustrates a schematic block diagram of an oil temperature management system for vehicles, according to an embodiment of the present subject matter;
Figure 2 illustrates a set of threshold temperatures related to the operation of the oil temperature management system, according to an embodiment of the present subject matter;
Figure 3 illustrates a schematic block diagram of a heating unit of the oil temperature management system, according to an embodiment of the present subject matter;
Figure 4 illustrates a schematic block diagram of a cooling unit of the oil temperature management system, according to an embodiment of the present subject matter; and
Figure 5 illustrates a method of controlling temperature of oil stored in a hydraulic tank of a vehicle, according to an embodiment of the present subject matter.
Further, the person skilled in the art will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

DETAILED DESCRIPTION OF FIGURES
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which this invention belongs. However, one of ordinary skill in the art will readily recognize that the present subject matter for intelligent oil temperature management system and method using the components/accessories/devices for the operation of hydraulic aggregates is not intended to be limited to the embodiments described, but is to be accorded the widest scope consistent with the principles and features described herein.
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
Figure 1 illustrates an oil temperature management system 100, hereinafter “the system 100”, for controlling temperature of oil stored in a hydraulic tank of a vehicle, according to an embodiment of the present subject matter. In an example, the system 100 may include a hydraulic tank 102, a temperature sensor 104, a controller 106, a heating unit 108, and a cooling unit 110. In an example, the system 100 may operate to control the temperature of oil stored in the hydraulic tank 102. In an example, the system 100 may further include a display unit 112 and an alarm unit 114.
In an example, the hydraulic tank 102 may be configured to store oil therein. The temperature sensor 104 may be configured to monitor and communicate the temperature of the oil in the hydraulic tank 102 to the controller 106. Accordingly, the controller 106 may operate at least one of the heating unit 108 and the cooling unit 110 to maintain the temperature of the oil at a desired temperature or within a desired temperature range.
As mentioned above, in an example embodiment, the temperature sensor 104 may be configured to monitor the temperature of the oil stored in the hydraulic tank 102. To that end, in an example, the temperature sensor 104 may measure the temperature continuously, i.e., at all times. In another example, the temperature sensor 104 may measure the temperature after predefined time intervals. Post measuring, the temperature sensor 104 may transmit the measured temperature to the controller 106.
In an example embodiment, the controller 106 may be configured to compare the received measured temperature with a set of threshold temperatures and accordingly operate the heating unit 108 and the cooling unit 110. An example set 200 of threshold temperatures is illustrated in Figure 2. The set 200 comprises at least a first threshold temperature 202, a second threshold temperature 204, a third threshold temperature 206, a fourth threshold temperature 208, and a fifth threshold temperature 210.
In an example embodiment, the first threshold temperature 202 and the third threshold temperature 206 may be correlated to the heating unit 108. That is, the controller 106 may perform the activation and the deactivation of the heating unit 108 based on the first threshold temperature 202 and the third threshold temperature 206, respectively. In an example, the first threshold temperature 202 and the third threshold temperature 206 represent a low ambient temperature range. Herein, the first threshold temperature 202 maybe minus 10 degrees and the third threshold temperature 206 maybe plus 10 degrees.
Furthermore, in an example embodiment, the second threshold temperature 202 and the fourth threshold temperature 208 may be correlated to the cooling unit 110. That is, the controller 106 may perform the activation and the deactivation of the cooling unit 110 based on the second threshold temperature 202 and the fourth threshold temperature 208, respectively. In an example, the second threshold temperature 204 and the fourth threshold temperature 208 represent a high ambient temperature range. Herein, the second threshold temperature 204 maybe plus 55 degrees and the fourth threshold temperature 208 maybe plus 40 degrees. In an example, the third threshold temperature 206 and the fourth threshold temperature 208 may represent a normal ambient temperature range.
Furthermore, in an example embodiment, the controller 106 may be configured to deactivate the cooling unit 110 based on the fifth threshold temperature 210. In an example, the fifth threshold temperature 210 maybe plus 65 degrees.
Continuing with the operation of the system 100, in an example, if the controller 106 determines that the measured temperature is less than the first threshold temperature 202, the controller 106 may activate the heating unit 108. Accordingly, the heating unit 108 operates to cause heating of the oil in the hydraulic tank 102. Now, as the temperature of the oil rises, the controller 106 may deactivate the heating unit 108 when the measured temperature becomes greater than the third threshold 206.
Furthermore, in an example, if the controller 106 determines that the measured temperature is greater than the second threshold temperature 204, the controller 106 may activate the cooling unit 110. Accordingly, the cooling unit 110 operates to cause cooling of the oil in the hydraulic tank 102. Now, as the temperature of the oil decreases, the controller 106 may deactivate the cooling unit 108 when the measured temperature becomes less than the fourth threshold 208. In an example, when the temperature of the oil is in the normal ambient temperature range, the controller 106 keeps both the heating unit 108 and the cooling unit 110 deactivated.
Furthermore, in an example, if the controller 106 determines that despite the activation of the cooling unit 110, the measured temperature is now greater than the fifth threshold, the controller 106 may deactivate the cooling unit 110 and may issue notifications using the display 112 and the alarm unit 114.
Figure 3 illustrates one or more components of the heating unit 108, according to an embodiment of the present subject matter. As shown in the figure, the heating unit 108 may include includes one or more heating coils 300-1, 300-2, ..., and 300-N, and a power unit 302. In an example embodiment, each of the heating coils 300 may have a rating of 500 W. In an example, the power unit 302 may be a 24V power supply. In an example embodiment, the power unit 302 may be activated by the controller 106 when the measured temperature becomes less than the first threshold 202. Accordingly, the power unit 302 switches ON the heating coils 300. Furthermore, the power unit 302 may be deactivated by the controller 106 when the measured temperature becomes greater than the third threshold 206.
Figure 4 illustrates one or more components of the cooling unit 110, according to an embodiment of the present subject matter. As shown in the figure, the cooling unit 110 may include a thermo-switch 402, a cooling fan 404, and a cut off relay switch 406. In an example embodiment, the cooling fan 404 may be a DC motor enabled fan. In an example embodiment, the thermo-switch 402 may be activated by the controller 106 when the measured temperature becomes greater than the second threshold 204. Accordingly, the thermo-switch 402 switches ON the cooling fan 404. Furthermore, the thermo-switch 302 may be shut OFF by the controller 106 when the measured temperature becomes less than the fourth threshold 208. In an example embodiment, the cut-off relay switch 406 may be activated by the controller 106 when the measured temperature becomes greater than the fifth threshold 210. The cut-off relay switch 406 shuts down the electrical supply to the cooling fan 404.
Figure 5 illustrates a method 500 of controlling temperature of oil stored in a hydraulic tank of a vehicle, according to an embodiment of the present subject matter. In an embodiment, at block 502, a temperature of oil stored in a hydraulic tank of a vehicle is measured by a sensor.
At block 504, the measured temperature is compared with a set of threshold temperatures. In an example, the set of threshold temperatures comprises at least a first threshold temperature and a second threshold temperature, as explained above.
In an example, if it is determined based on the comparison that the measured temperature is lower than the first threshold temperature, the method proceeds to block 506. At block 506, a heating unit is activated to cause an increase in the temperature of the oil stored in the hydraulic tank. Furthermore, after the heating of the oil is commenced, at block 508, if it is determined that the measured temperature is greater than a third threshold temperature, the heating unit is deactivated.
In another example where at block 504 it is determined that the measured temperature is greater than the second threshold temperature, the method proceeds to block 510. At block 510, a cooling unit is activated to cause a decrease in the temperature of the oil, when the measured temperature is greater than the second threshold temperature. Furthermore, after the cooling of the oil is commenced, at block 512, if it is determined that the measured temperature is less than a fourth threshold temperature, the cooling unit is deactivated. Furthermore, in case despite the activation of the cooling unit, if the temperature still continues to increase and crosses a fifth threshold, then at step 514, electrical supply to the cooling unit is cut off. Furthermore, an alarm either through an alarm unit or a display may be provided to an operator of the vehicle.
While specific language has been used to describe the present subject matter, any limitations arising on account thereto, are not intended. As would be apparent to a person in the art, various working modifications may be made to the method in order to implement the inventive concept as taught herein. The drawings and the foregoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment.
,CLAIMS:We Claim:

1. A system (100) for controlling oil temperature in hydraulic tanks (102), comprising:
a temperature sensor (104) to measure a temperature of oil stored in a hydraulic tank (102);
a heating unit (108) to affect heating of the oil stored in the hydraulic tank (102);
a cooling unit (110) to affect cooling of the oil stored in the hydraulic tank (102); and
a controller (106) to:
obtain the measured temperature;
compare the measured temperature with a set of threshold temperatures, wherein the set of threshold temperatures comprises at least a first threshold temperature and a second threshold temperature;
activate the heating unit (108) to cause an increase in the temperature, when the measured temperature is lower than the first threshold temperature; and
activate the cooling unit (110) to cause a decrease in the temperature, when the measured temperature is greater than the second threshold temperature.

2. The system (100) as claimed in claim 1, wherein the controller (106) further is to deactivate the heating unit (108) when the temperature is greater than a third threshold temperature.
3. The system (100) as claimed in claim 1, wherein the controller (106) further is to deactivate the cooling unit (110) when the measured temperature is lower than a fourth threshold temperature.
4. The system (100) as claimed in claim 1, wherein the controller (106) further is to deactivate an electric supply from the cooling unit (110) when the measured temperature is greater than a fifth threshold temperature.
5. The system (100) as claimed in claim 1, wherein the controller (106) further is to trigger an alarm signal, prior to activation of the heating unit (108) and the cooling unit (110).
6. A method of controlling oil temperature in hydraulic tanks (102), the method comprising:
measuring a temperature of oil stored in a hydraulic tank (102) by a temperature sensor (104);
comparing the measured temperature with a set of threshold temperatures, wherein the set of threshold temperatures comprises at least a first threshold temperature and a second threshold temperature; and
activating one of a heating unit (108) and a cooling unit (110) based on the comparing, wherein the heating unit (108) is coupled to the hydraulic tank (102), wherein the cooling unit (110) is coupled to the hydraulic tank (102), wherein the heating unit (108) is activated to cause an increase in temperature when the measured temperature is lower than the first threshold temperature, and wherein the cooling unit (110) is activated to cause a decrease in the temperature when the measured temperature is greater than the second threshold temperature.

7. The method as claimed in claim 6, wherein the method further comprises:
comparing the measured temperature with a third threshold temperature; and
deactivating the heating unit (108) when the measured temperature is determined to be greater than the third temperature threshold.

8. The method as claimed in claim 6, wherein the method further comprises comparing the measured temperature with a fourth threshold temperature; and deactivating the cooling unit (110) when the measured temperature is determined to be lower than the fourth threshold temperature.
9. The method as claimed in claim 6, wherein the method further comprises of deactivating an electric supply when the measured temperature is determined to be greater than a fifth threshold temperature.
10. The method as claimed in claim 6, wherein the method further comprises of triggering an alarm signal prior to activating one of the heating unit (108) and the cooling unit (110).