Apparatus and method for controlling a fluid pump for a motor vehicle

Abstract

An apparatus for controlling a fluid pump for a motor vehicle includes: a first controller configured to actuate an electric prime mover of the fluid pump by impressing at least one motor current with an adapted current intensity and an adapted waveform; and a second controller configured to detect a rotational speed of the electric prime mover and to apply an adapted voltage to the electric prime mover on the basis of the detected rotational speed.

Claims

1-10. (canceled)

11. An apparatus (1) for controlling a fluid pump (100) for a motor vehicle (2), the apparatus comprising: a first controller (10) configured to actuate an electric prime mover (110) of the fluid pump (100) by impressing at least one motor current with an adapted current intensity and an adapted waveform; and a second controller (20) configured to detect a rotational speed of the electric prime mover (110) and to apply an adapted voltage to the electric prime mover (110) on the basis of the detected rotational speed.

12. The apparatus as claimed in claim 11, wherein the apparatus (1)is configured to compare the detected rotational speed of the electric prime mover (110) with a rotational speed threshold value for the electric prime mover (110).

13. The apparatus as claimed in claim 12, wherein the first controller (10) is configured to actuate the electric prime mover (110) if the detected rotational speed of the electric prime mover (110) is below the rotational speed threshold value for the electric prime mover (110).

14. The apparatus as claimed in claim 12, wherein the second controller (20) is configured to actuate the electric prime mover (110) if the detected rotational speed of the electric prime mover (110) is above the rotational speed threshold value for the electric prime mover (110).

15. The apparatus as claimed in claim 11, wherein the first controller (10) is configured to actuate the at least one motor current with the adapted waveform in accordance with a predefined field frequency.

16. The apparatus as claimed in claim 15, wherein fee first controller (10) is configured to read out the field frequency from a characteristic curve diagram, and/or the first controller (10) is configured to determine the field frequency using a gradient calculation.

17. The apparatus as claimed in claim 16, wherein the first controller (10) is configured to determine the gradient calculation taking into account a mass moment of inertia of a rotor of the electric prime mover (110).

18. A fluid pump (100) for a motor vehicle (2), wherein the fluid pump (100) comprises an apparatus (1) as claimed in claim 11.

19. The fluid pump (100) as claimed in claim 18, wherein the fluid pump (100) is a water pump or a fuel pump or an oil pump or a pump with an electric prime mover (110) configured as a synchronous machine with a permanent magnet.

20. A method for controlling a fluid pump (100) for a motor vehicle, the method comprising: detecting (S1) a rotational speed of the electric prime mover (110) and comparing the detected rotational speed with a rotational speed threshold value for the electric prime mover (110); impressing (S2) at least one motor current with an adapted current intensity and an adapted waveform into the electric prime mover (110) if the detected rotational speed of the electric prime mover (110) is below the rotational speed threshold value for the electric prime mover (110); and applying (S3) an adapted voltage to the electric prime mover (110) if the detected rotational speed of the electric prime mover (110) is above the rotational speed threshold value for the electric prime mover (110).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The appended drawings are intended to permit better understanding of the embodiments of the present invention. The appended drawings illustrate embodiments and serve to clarify concepts of the invention in conjunction with the description.

[0035] Other embodiments and many of the specified advantages arise in view of the drawings. The illustrated elements of the drawings are not necessarily shown, true to scale with respect to one another. In the drawings:

[0036] FIG. 1 shows a schematic illustration of an apparatus for controlling a fluid pump for a motor vehicle according to an embodiment of the present invention;

[0037] FIG. 2 shows a schematic illustration of a flow chart for controlling a fluid pump for a motor vehicle according to a further embodiment of the present invention;

[0038] FIG. 3 shows a schematic illustration of a fluid pump for a motor vehicle according to a further advantageous embodiment of the present invention; and

[0039] FIG. 4 shows a schematic illustration of a diagram illustrating the winding section current of a fluid pump over a specific rotational speed range of the fluid pump in order to clarify the present invention.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

[0040] In the figures of the drawings, identical reference symbols denote identical or functionally identical elements, parts, components or method steps, unless stated otherwise.

[0041] FIG. 1 shows a schematic illustration of an apparatus for controlling a fluid pump for a motor vehicle.

[0042] The apparatus 1 comprises, for example, a first controller 10 and a second controller 20.

[0043] The first controller is configured, for example, to actuate an electric prime mover 110 of the fluid pump 100 by impressing at least one motor current with an adapted current intensity and an adapted waveform.

[0044] The second controller is configured, for example, to detect a rotational speed of the electric prime mover and to apply an adapted voltage to the electric prime mover on the basis of the detected rotational speed.

[0045] FIG. 2 shows a schematic illustration of a flow chart for controlling a fluid pump for a motor vehicle according to a further embodiment of the present invention.

[0046] The method for controlling the fluid pump 100 (see FIG. 3) for a motor vehicle 2 comprises the following steps here;

[0047] As a first step of the method, for example a rotational speed of the electric prime mover 110 (see FIG. 3) is detected (S1), and the detected rotational speed is compared, which a rotational speed threshold value for the electric prime mover 110.

[0048] As a second step of the method, for example at least one motor current with an adapted current intensity and an adapted waveform is impressed (S2) into the electric prime mover 110 if the detected rotational speed of the electric prime mover 110 is below the rotational speed threshold value for the electric prime mover 110.

[0049] As a third step of the method, for example an adapted voltage is applied (S3) to the electric prime mover 110 on the basis of the detected rotational speed if the detected rotational speed of the electric prime mover 110 is above the rotational speed threshold value for the electric prime mover.

[0050] FIG. 3 shows a schematic illustration of a fluid pump according to a further embodiment of the present invention.

[0051] A fluid pump 100 for a motor vehicle 2 comprises, for example, an apparatus 1 as pump control electronics and an electric prime mover 110.

[0052] FIG. 4 shows a schematic illustration of a diagram in order to clarify the invention.

[0053] For example a rotational speed of a fluid pump is recorded on the X axis of the diagram.

[0054] For example the winding section current of the fluid pump is plotted on the Y axis of the diagram.

[0055] The characteristic curves or current curves for different pressures P0 to P4 illustrated in FIG. 4 result in a characteristic curve diagram.

[0056] The indicated arrow in the diagram represents the direction of the increasing system pressure.

[0057] A dashed line parallel to the y axis represents a boundary with the normal operation. In other words, this is a rotational speed threshold value for the electric prime mover 110, and, for example, the boundary between the low rotational speed range and the normal operation of the fluid pump is at a rotational speed of the electric prime mover 110 of the fluid pump of 100 rpm or 500 rpm or 1000 rpm or 2000 rpm.

[0058] The boundary with the normal operation therefore differentiates a low rotational speed range from a normal operating range of the fluid pump with respect to its rotational speed.

[0059] FIG. 4 shows a winding section current/rotational speed diagram with current boundaries of the winding section current for low rotational speed ranges and normal operating ranges, and in the low rotational speed range the curves correspond to the impressed current or winding section current at predetermined pressures P0 to P4.

[0060] FIG. 4 represents an adapted current intensity, wherein the controllers can also use an adapted waveform for the motor current, for example a sine form or a ramp form.

[0061] In the normal operating range or normal rotational speed range, the winding section current is substantially lower at respectively identical pressures P0 to P4. However, the pump drive current or the fluid pressure, or in the case of a fuel pump the fuel pressure, can also be correspondingly limited during normal operation if specific rotational-speed-dependent values are reached.

[0062] Although the present invention has been described above with reference to preferred exemplary embodiments, it is not restricted thereto but rather can be modified in a variety of ways. In particular, the invention can be changed or modified in various ways without departing from the core of the present invention.

[0063] In addition, it is to be noted that “comprising” and “having” do not exclude other elements or steps, and “a” or “an” does not exclude a plurality.

[0064] In addition it is to be noted that features or steps which have been described with reference to one of the above exemplary embodiments can also be used in combination with other features or steps of other exemplary embodiments described above. Reference symbols in the claims are not to be considered as restrictions.

[0065] Thus, while there have been 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 he 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.