ELECTRIC COOLANT PUMP

Abstract

An electric coolant pump may include a valve device controlled at a discharge side by pressure. The valve device may include a coolant inlet, a first coolant outlet, and a second coolant outlet. The valve device may be configured to at least one of open and close at least one of the first coolant outlet and the second coolant outlet based on a selected operating point and a pressure in a coolant.

Claims

1. An electric coolant pump comprising a valve device controlled at a discharge side by pressure, the valve device including a coolant inlet, a first coolant outlet, and a second coolant outlet, wherein the valve device is configured to, based on a selected operating point and a pressure in a coolant, at least one of open and close at least one of the first coolant outlet and the second coolant outlet.

2. The coolant pump as claimed in claim 1, wherein, in a first operating point, the coolant pump is switched off and at least the first coolant outlet is open.

3. The coolant pump as claimed in claim 2, wherein: in a second operating point, the coolant pump has a rotational speed at which the first coolant outlet is open and the second coolant outlet is closed; in a third operating point, the coolant pump has a second rotational speed at which the first coolant outlet and the second coolant outlet are open; and in a fourth operating point, the coolant pump has a third rotational speed at which the first coolant outlet is closed and the second coolant outlet is open.

4. The coolant pump as claimed in claim 3, wherein the valve device includes a valve body, and wherein at least one of: in the first operating point and the second operating point, the valve body is arranged in a first position, in which the valve body blocks the second coolant outlet and uncovers the first coolant outlet; in the third operating point, the valve body is arranged in a second position, in which the valve body uncovers the first coolant outlet and the second coolant outlet; and in the fourth operating point, the valve body is arranged in a third position, in which the valve body blocks the first coolant outlet and uncovers the second coolant outlet.

5. The coolant pump as claimed in claim 1, wherein the valve device is continuously adjustable based on a rotational speed of the coolant pump.

6. The coolant pump as claimed in claim 4, wherein the valve body is structured as a valve piston and is adjustable in a translatory manner.

7. The coolant pump as claimed in claim 4, further comprising a spring device prestressing the valve body in the first position.

8. The coolant pump as claimed in claim 1, further comprising a temperature sensor and a control device communicatively connected thereto configured to control a power of the coolant pump based on a temperature of the coolant.

9. The coolant pump as claimed in claim 1, wherein the valve device is one of arranged separately from a body of the coolant pump and is integrated with the body of the coolant pump.

10. A motor vehicle comprising an internal combustion engine, a radiator, a heat exchanger, a coolant pump, and a valve device controlled at a discharge side by pressure, the valve device including a coolant inlet, a first coolant outlet, connected to an inlet of the coolant pump, and a second coolant outlet, wherein the valve device is configured to, based on a selected operating point of the coolant pump and a pressure in a coolant, at least one of open and close at least one of the first coolant outlet and the second coolant outlet, wherein the coolant inlet and the first coolant outlet are connected to the internal combustion engine, and the second coolant outlet is connected to the radiator.

11. The motor vehicle as claimed in claim 10, wherein, in a first operating point of the cooling pump, the coolant pump is switched off and at least the first coolant outlet is open.

12. The motor vehicle as claimed in claim 11, wherein: in a second operating point of the cooing pump, the coolant pump has a rotational speed at which the first coolant outlet is open and the second coolant outlet is closed; in a third operating point of the cooing pump, the coolant pump has a second rotational speed at which the first coolant outlet and the second coolant outlet are open; and in a fourth operating point of the cooing pump, the coolant pump has a third rotational speed at which the first coolant outlet is closed and the second coolant outlet is open.

13. The motor vehicle as claimed in claim 12, wherein the valve device includes a valve body, and wherein at least one of: in the first operating point and the second operating point, the valve body is arranged in a first position, in which the valve body blocks the second coolant outlet and uncovers the first coolant outlet; in the third operating point, the valve body is arranged in a second position, in which the valve body uncovers the first coolant outlet and the second coolant outlet; and in the fourth operating point, the valve body is arranged in a third position, in which the valve body blocks the first coolant outlet and uncovers the second coolant outlet.

14. The motor vehicle as claimed in claim 13, wherein the valve body is structured as a valve piston and is adjustable in a translatory manner.

15. The motor vehicle as claimed in claim 13, further comprising a spring device prestressing the valve body in the first position.

16. The motor vehicle as claimed in claim 10, wherein the valve device is continuously adjustable based on a rotational speed of the coolant pump.

17. The motor vehicle as claimed in claim 10, further comprising a temperature sensor and a control device communicatively connected thereto configured to control a power of the coolant pump based on a temperature of the coolant.

18. The motor vehicle as claimed in claim 10, wherein one of: the valve device is arranged separately from a body of the coolant pump; and the valve device is integrated with the body of the coolant pump.

19. An electric coolant pump comprising a valve device controlled at a discharge side by pressure, the valve device including a coolant inlet, a first coolant outlet, and a second coolant outlet, wherein the valve device is configured to, based on a selected operating point and a pressure in a coolant, at least one of open and close at least one of the first coolant outlet and the second coolant outlet via adjusting a position of a valve body.

20. The coolant pump as claimed in claim 19, wherein: in a first operating point, the coolant pump is switched off and at least the first coolant outlet is open; in a second operating point, the coolant pump has a rotational speed at which the first coolant outlet is open and the second coolant outlet is closed; in a third operating point, the coolant pump has a second rotational speed at which the first coolant outlet and the second coolant outlet are open; and in a fourth operating point, the coolant pump has a third rotational speed at which the first coolant outlet is closed and the second coolant outlet is open.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings show, in each case schematically:

[0017] FIG. 1 shows a partly sectional coolant pump according to the invention, having a valve device with valve bodies,

[0018] FIG. 2 shows an illustration as in FIG. 1, but with another valve device,

[0019] FIG. 3 shows a schematic diagram of an installation situation of the coolant pump according to the invention in a motor vehicle according to the invention,

[0020] FIG. 4 shows an illustration as in FIG. 3, but with another arrangement of the valve device,

[0021] FIG. 5 shows a cooling system which does not fall under the invention, having a coolant pump with three valve units.

DETAILED DESCRIPTION

[0022] According to FIGS. 1 to 4, an electric coolant pump 1 according to the invention for delivering a coolant 2 has a valve device 6 which is controlled at the discharge side and by pressure and has a coolant inlet 3, a first coolant outlet 4 and a second coolant outlet 5. In this case, the coolant pump 1 according to the invention is adjustable between a plurality of operating points, in particular between a first, a second, a third and a fourth operating point. In this case, the valve device 6 is either integrated in the coolant pump 1 (c.f. FIGS. 1 and 2) or is arranged separately from this (c.f. FIGS. 3 and 4) and formed such that, depending on the selected operating point of the coolant pump 1 and therefore the coolant pressure p, it opens and/or closes the first or second coolant outlet 4, 5 or simultaneously opens the first and second coolant outlet 4, 5. In this case, controlled at the discharge side and by pressure should be understood to mean that, at the valve device 6, the coolant outlets 4, 5 can be opened/closed by means of a valve body 7 which is adjustable depending on the pressure.

[0023] As can be seen in FIGS. 1 and 2, the coolant pump 1 according to the invention and the valve device 6 form a common unit 19 which, compared to hitherto used coolant pumps with thermostat valves arranged separately therefrom, is considerably compacter in design and thus offers considerable advantages in terms of the installation space.

[0024] The pressures in the respective operating points are achieved by a corresponding rotational speed of the coolant pump 1, so that, in the second operating point, the coolant pump 1 has a rotational speed at which the first coolant outlet 4 is opened and the second coolant outlet 5 is closed, wherein, in the third operating point, the coolant pump 1 has a rotational speed at which the first coolant outlet 4 and the second coolant outlet 5 are opened, and wherein, in a fourth operating point, the coolant pump 1 has a rotational speed at which the first coolant outlet 4 is closed and the second coolant outlet 5 is opened.

[0025] With regard to the construction of the valve device 6 according to the invention, reference is made below to FIGS. 2 and 4, from which it can be seen that the valve device 6 possesses a valve body 7 which, in this case, is formed as an adjustable valve piston 8 and which, in the first and second operating point, assumes a first position (far right), in which it blocks the second coolant outlet 5 and uncovers the first coolant outlet 4. In the third operating point, on the other hand, the valve body 7 assumes a second position, in which it uncovers the first coolant outlet 4 and the second coolant outlet 5 (c.f. FIGS. 3 and 4). In the fourth operating point, the valve body 7 assumes a third position, in which it blocks the first coolant outlet 4 and uncovers the second coolant outlet 5. Moreover, a spring device 9, for example a simple helical spring, is provided, which prestresses the valve body 7 in its first position, in which the second coolant outlet 5 is blocked. In this case, the spring device 9 exerts a force on the valve body 7 which, in relation to the surface thereof, corresponds to a pressure p.sub.F. A temperature sensor 10 and a control device 11 communicatively connected thereto can likewise be provided for controlling the operating points of the coolant pump 1 depending on the temperature of the coolant 2. In this case, the valve device 6 is continuously adjustable depending on the rotational speed of the coolant pump 1. In this case, it is, of course, also alternatively conceivable that, instead of the valve body 7 formed as a valve piston 8, the valve device 6 according to the invention can also have other valve bodies 7, so that the valve device 6 can also be formed as a ball valve or as a disk valve, for example.

[0026] Observation of FIGS. 3 and 4 now shows a motor vehicle 12 having an internal combustion engine 13, a radiator 14, a heat exchanger 15 in an air-conditioning system which is not otherwise shown, and having a coolant pump 1 according to the passages above. In this case, a coolant inlet 16 of the coolant pump 1, like the first coolant outlet 4 of the valve device 6, is connected to the internal combustion engine 13, whilst a second coolant outlet 5 of the valve device 6 is connected to the radiator 14.

[0027] In this case, in terms of controlling a coolant flow 2, the coolant pump 1 according to the invention functions as follows:

[0028] Cooling of the internal combustion engine 13 is not required or desired upon a cold start thereof in order to accelerate the heating of the internal combustion engine 13 and therefore achieve a more rapid lowering of the emissions. During this cold-start phase, the coolant pump 1 is located in its first operating point, in which it does not bring about a build-up of pressure and does not deliver coolant 2 and is therefore switched off. If the temperature of the coolant 2 increases, this is detected via the temperature sensor 10, for example, which, in the present case according to FIG. 1, is arranged in the region of the coolant pump 1, but can, of course, additionally or alternatively also be positioned at another point in the cooling system 18. If the temperature of the coolant 2 reaches a certain value, the control device 11 connected to the temperature sensor 10 adjusts the coolant pump 1 to its second operating point, in which the second coolant outlet 5 is still closed and a coolant flow circulates exclusively via the internal combustion engine 13 and, for example, the heat exchanger 15 of the air-conditioning system of the motor vehicle 12. Also, in this case, only moderate cooling of the internal combustion engine 13 is required in this second operating point. The pressure p of the coolant 2 which is generated in the second operating point is lower than the pressure p.sub.F acting on the valve body 7 by means of the spring device 9, so that the spring device 9 prestresses the valve body 7 in its first position in opposition to the coolant pressure p and fixes it there.

[0029] If the temperature of the coolant 2 increases further, this is likewise detected by the temperature sensor 10 and, upon reaching a further limit value, results in the control device 11 adjusting the coolant pump 1 to its third operating point, in which both the delivery power of the coolant pump 1 and also the pressure p generated thereby in the coolant 2 increase significantly. This results in the coolant pressure p being greater than the pressure p.sub.F applied by the spring device 9 so that, in the third operating point, the valve body 7 is adjusted to the right according to FIG. 3, compresses the spring device 9 and simultaneously uncovers the second coolant outlet 5, whereby the coolant flow now circulates via the internal combustion engine 13 and the radiator 14 and via the coolant pump 1 back to the internal combustion engine 13. However, some of the coolant flow 2 still flows via the heat exchanger 15. In this case, the maximum cooling power is produced in the fourth operating point since the coolant pump 1 has a rotational speed at which the first coolant outlet 4 is closed the second coolant outlet 5 of the valve device 6 is opened. In the fourth operating point, the valve body 7 assumes its third position, in which it blocks the first coolant outlet 4 of the valve device 6 and uncovers the second coolant outlet 5 so that all of the coolant flow 2 flows via the internal combustion engine 13 and the radiator 14.

[0030] In this case, to control the valve device 6, the coolant pump 1, according to FIGS. 1 to 5, is connected to a pressure chamber 17 of the valve device 6 at its coolant outlet 20 via a pressure line 21.

[0031] In this case, according to FIG. 3, the radiator 14 is arranged upstream of the coolant pump 1 whilst, according to FIG. 4, it is arranged downstream thereof.

[0032] In this case, FIG. 1 shows a valve device 6 which has two spring devices 9 and two valve bodies 7 respectively prestressed thereby. In this case, to realize the inventive idea, the spring strengths of the spring devices 9 are different so that, in the third operating point, only the valve body 7 associated with the first coolant outlet 4 is adjusted, whilst additionally, in the fourth operating point, the valve body 7 associated with the second coolant outlet 5 is also adjusted.

[0033] According to FIG. 5, a motor vehicle 12 has a cooling system 18 and a coolant pump 1. The, in particular electric, coolant pump 1 is formed for delivering a coolant 2. Likewise provided are valve devices 6a, 6b and 6c which are arranged separately from the coolant pump 1 and each have a coolant inlet 3a, 3b, 3c and a coolant outlet 4a, 4b, 4c, which are connected to an outlet 20 of the coolant pump 1.

[0034] In this case, the coolant pump 1 is adjustable between a plurality of operating points, in particular between a first, a second, a third and a fourth operating point. The valve devices 6a, 6b, 6c are formed such that they open, partially open or close depending on the selected operating point of the coolant pump 1 and therefore the coolant pressure p. In this case, the individual coolant outlets 4a, 4b, 4c are connected to individual assemblies, for example a heat exchanger 15 of an air-conditioning system or a radiator 14. As can be seen in FIG. 5, the valve devices 6a, 6b and 6c are arranged separately from the coolant pump 1 and at the discharge side thereof, whereby a decentralized separation of the components 1, 6a, 6b and 6c, which is optimized in terms of the installation space, can also take place.

[0035] In the first operating point, the coolant pump 1 is switched off and all valve devices 6a, 6b, 6c are closed. Therefore, a pressure p generated by the coolant pump 1 does not prevail in the cooling system 18.

[0036] In the second operating point, the coolant pump 1 generates a pressure p in the coolant 2, at which at least one valve device 6c, and therefore its coolant outlet 4c, are opened and at least one further valve device 6a, 6b and its coolant outlet 4a, 4b are closed, whilst, in a third operating point, the coolant pump 1 generates a pressure p in the coolant 2, at which at least two valve devices 6b, 6c, and therefore their coolant outlets 4b, 4c, are opened and at least one further valve device 6a and its coolant outlet 4a are closed. This is illustrated in FIG. 5. In a fourth operating point, the coolant pump 1 generates a pressure p in the coolant 2/cooling system 18, at which all valve devices 6a, 6b, 6c are opened. In this case, the coolant pump 1 is connected to a respective pressure chamber 17a, 17b, 17c of the associated valve devices 6a, 6b, 6c at its coolant outlet 20.

[0037] In this case, a valve body 7a, 7b, 7c which is located in its closed position always closes the associated valve device 6a, 6b, 6c and therefore also its coolant inlets 3a, 3b, 3c or coolant outlets 4a, 4b, 4c.

[0038] With regard to the construction of the valve device 6, reference is made below to FIG. 5, from which it can be seen that the valve devices 6a, 6b, 6c each possess a valve body 7a, 7b, 7c which are formed as adjustable valve pistons 8a, 8b, 8c. Moreover, a spring device 9a, 9b, 9c, for example a simple helical spring, is provided in each case, which prestresses the associated valve body 7a, 7b, 7c in its first position, in which the associated valve device 6a, 6b, 6c is in turn blocked.

[0039] In the first and second operating point, the valve body 7a, 7b, 7c assumes a first position (c.f. the valve body 7a), in which the associated coolant inlet 3a, 3b, 3c is blocked. In the third operating point, on the other hand, the valve body 7a, 7b, 7c assumes a second position, in which it opens the associated valve device 6a, 6b, 6c and uncovers the associated coolant inlet 3a, 3b, 3c (c.f. valve body 7b, 7c). In this case, the spring device 9a, 9b, 9c exerts a force on the associated valve body 7a, 7b, 7c which, in relation to the surface thereof, corresponds to a pressure p.sub.F. In this case, the coolant outlet 20 of the coolant pump 1 is connected to the respective pressure chamber 17a, 17b, 17c of the associated valve devices 6a, 6b, 6c and, depending on the pressure, prestresses the valve body 7a, 7b, 7c in opposition to the spring device 9a, 9b, 9c. In this case, the individual spring devices 9a, 9b, 9c have an individual spring strength, whereby, at the same coolant pressure p, the one valve device 6b, 6c is already opened whilst the other valve device 6a still remains closed. In this case, the valve devices 6a, 6b, 6c are continuously adjustable depending on the rotational speed of the coolant pump 1.

[0040] For example, cooling of the internal combustion engine 13 is not required or desired upon a cold start thereof in order to accelerate the heating of the internal combustion engine 13 and therefore achieve a more rapid lowering of the emissions. During this cold-start phase, the coolant pump 1 is located in its first operating point, in which it does not bring about a build-up of pressure and does not deliver coolant 2 and is therefore switched off. If the temperature of the coolant 2 increases, this is detected via the temperature sensor 10, for example, can be positioned at virtually any point in the coolant system 18, in particular also on the internal combustion engine 13. If the temperature of the coolant 2 reaches a certain value, the control device 11 connected to the temperature sensor 10 adjusts the coolant pump 1 to its second operating point, in which the pressure p generated by the delivery power of the coolant pump 1 is at a level such that at least one valve device 6c opens if its spring strength is the lowest, whilst the valve devices 6b and 6a are still closed and a coolant flow 2 circulates exclusively via the internal combustion engine 13 and, for example, the heat exchanger 15 of the air-conditioning system of the motor vehicle 12. In this second operating point, a moderate cooling of the internal combustion engine 13 is required. The pressure p of the coolant 2 which is generated in the second operating point is lower than the pressure p.sub.F acting on the valve body 7a, 7b by means of the spring device 9a, 9b, so that the spring device 9a, 9b prestresses the valve body 7a, 7b in its first position in opposition to the coolant pressure p.

[0041] If the temperature of the coolant 2 increases further, this is likewise detected by the temperature sensor 10 and, upon reaching a further limit value, results in the control device 11 adjusting the coolant pump 1 to its third operating point, in which both the delivery power of the coolant pump 1 and also the pressure p generated thereby in the coolant 2 increase. This results in the coolant pressure p being greater than the pressure p.sub.F applied by the spring device 9b so that, in the third operating point, the valve body 7b compresses the spring device 9b and simultaneously uncovers the associated coolant inlet 3b, whereby the coolant flow 2 now circulates via the internal combustion engine 13, the radiator 14 and the heat exchanger 15 and via the coolant pump 1 back to the internal combustion engine 13. Therefore, some of the coolant flow 2 still flows via the heat exchanger 15.

[0042] If the temperature of the coolant 2 increases further, this is likewise detected by the temperature sensor 10 and, upon reaching a further limit value, results in the control device 11 adjusting the coolant pump 1 to its fourth operating point, in which both the delivery power of the coolant pump 1 and the pressure p generated thereby in the coolant 2 increase. This results in the coolant pressure p being reached and being greater than the pressure p.sub.F applied by the spring devices 9a, 9b, 9c, so that all of the valve devices 6a, 6b, 6c open in the fourth operating point.