EP1608876B1 - Coolant pump, especially electric convection-cooled coolant pump with integrated directional control valve, and corresponding method - Google Patents

Abstract

A coolant pump and method thereof for a coolant circuit of the internal combustion engine of a motor vehicle including at least a radiator circuit and a bypass circuit is disclosed. The coolant pump contains a coolant pump housing ( 14 ) which is provided with an intake pipe ( 22 ), a bypass pipe ( 24 ), and a pressure pipe ( 34 ). A coolant pump electric motor ( 26 ) is arranged in the coolant pump housing ( 14 ), the motor housing ( 28 ) of which is situated in the coolant flow, drives a pump impeller ( 32 ) via a pump shaft ( 30 ). A directional control valve ( 40 ) is integrated into the coolant pump housing ( 14 ). The intake pipe ( 22 ) is arranged in the area of the end of the pump motor facing away from the pump impeller ( 32 ). Furthermore the bypass pipe is arranged in an area downstream of the intake pipe ( 22 ).The pressure pipe ( 34 ) is arranged in an area downstream of the bypass pipe ( 24 ). Only the coolant that can be taken in by the radiator via the intake pipe is adapted to be guided past the pump motor in a peripheral flow ( 50 ) in particular through a flow channel ( 56 ) limited by the outer wall ( 52 ) of the pump motor housing ( 28 ) and the facing inner wall ( 54 ) of the pump housing and/or the facing inner wall ( 60 ) of the directional control valve ( 40 ).

Description

The present invention relates to a coolant pump according to the preamble of claim 1, and a method for this according to the preamble of claim 22.

Recent studies on the fuel consumption of automotive internal combustion engines show that consistent thermal management in a modern automotive internal combustion engine can provide fuel savings of about 3 to 5%. The thermal management refers to those measures that lead to the energetically and thermo-mechanically optimal operation of an internal combustion engine. For this purpose, an active control of the heat flows and thus the temperature distribution in the engine is required.

Thus, a precise control of the coolant flow rate and the temperature of the enforced coolant is required. Accordingly, coolant pumps are increasingly used instead of the conventional, rigidly coupled to the engine speed coolant pumps whose speed is variable and thus the flow rate is adjustable.

For this purpose, the applicant already has an exemplary electric coolant pump in the application DE 100 47 387 discussed. This proven electric coolant pump has been developed consistently by the applicant. An ensuing, improved electric coolant pump with integrated directional control valve is in the DE 102 07 653 described.

The discussed there electrical coolant pump with integrated directional control valve has a coolant pump housing, which has a suction nozzle for the inlet from the radiator, a bypass nozzle for the inlet of the bypass circuit and a discharge nozzle for the supply or return of the coolant to the vehicle engine. In the coolant pump housing, a coolant pump electric motor is arranged, the motor housing is flowed around by the circulated coolant. The pump motor drives a pump impeller via a pump shaft to circulate the coolant. Suction nozzle and bypass nozzle upstream of the integrated in the coolant pump directional control valve in the inlet to the pump are integrated so that when open directional control valve, a mixture of cooler coolant coming from the radiator and directly coming from the motor vehicle heated coolant sucked by the pump impeller and the pump motor over to the downstream pressure nozzle for the supply or return of this coolant mixture to the motor vehicle engine.

Although this electric coolant pump with integrated directional control valve has already proven itself, recent investigations by the applicant showed that the electrical and / or electronic components installed in the coolant pump can at least temporarily be exposed to an extremely high heat load despite the flow around the electric motor housing with the circulated coolant mixture.

For example, the maximum temperature of the cooled by the radiator, pending at the output and from there to the pump coolant flowing 113 ° C. This desired upper value has been set by the automotive industry for the design of automotive radiators. This is to ensure that when operating a motor vehicle, even in extremely hot areas, such as in the desert, cooled coolant for the motor vehicle engine is available in a temperature range available with a maximum Input temperature of 113 ° C supplied to the engine, with a remaining temperature range of at least 7 ° C to 17 ° C to a maximum allowed for conventional coolant upper limit of 120 ° C to at most 130 ° C still sufficient heat from the engine and take to the radiator can dissipate.

Accordingly, the temperature of the coolant carried away from the engine can easily reach 120 ° C or, in unfavorable cases, more, ie up to 130 ° C.

Further, in modern internal combustion engines, a short circuit or bypass circuit is provided, can be returned to the heated coolant from the engine coming via the coolant pump directly to the engine. Thus, for example, during the cold start the Anwärmphase the engine shortened overall, achieved a rapid warm-up of the cylinder tube after the cold start and a control of the tribologically optimum temperature are possible.

The coolant pump installed electronic as well as electrical components, such as the electric motor that drives the pump impeller or the electronic components, sensors, transducers or control loops that allow control and / or regulation of the engine speed, the pump power, the valve position or other functions point a limited temperature compatibility and are therefore not infinitely high temperatures exposable. At a reasonable price affordable, approved in the automotive industry and available in sufficient quantities components can be operated in some cases only a maximum of 120 ° C. Above threatens the rapid heat death of such electrical and / or electronic components. Accordingly, for example, in a circulation of possibly up to 130 ° C heated coolant of the bypass circuit by the coolant pump can not be ruled out that the electrical and / or electronic components of the coolant pump are exposed to a heat load, which leads to failure of these components.

Last but not least, the two switching positions of a 3/2-way valve, such as in the in the DE 102 07 653 The electric coolant pump discussed by the automotive industry has sometimes been considered insufficient for more extensive applications.

Accordingly, it is an object of the present invention, while avoiding the aforementioned disadvantages, to propose a flow-cooled electric coolant pump with integrated directional control valve, in which there is no risk of overheating of the electronic and / or electrical components installed therein. It is another object of the present invention to provide a method suitable for this purpose.

This object is achieved in device-technical terms by the features of claim 1, and in procedural terms by the features of claim 22nd

It is - starting from the in the DE 102 07 653 described electric coolant pump with integrated directional valve - an advanced coolant pump of this type proposed. The newly proposed coolant pump for a coolant circuit of a motor vehicle internal combustion engine, which has at least one radiator circuit and a bypass circuit, has a coolant pump housing having a suction port for the inlet from the radiator, a bypass port for the inlet of the bypass circuit and a pressure port for having the supply of the coolant from the motor vehicle engine. Furthermore, the coolant pump has a coolant pump housing arranged in the coolant pump housing, the motor housing flows around the coolant is, and drives a pump impeller via a pump shaft. Furthermore, the coolant pump has a directional control valve integrated in the coolant pump housing.

It is proposed for the first time that the suction nozzle is arranged in the region of the pump impeller facing away from the end of the pump motor. Furthermore, it is proposed for the first time that the bypass nozzle is arranged in a region downstream of the suction nozzle, in particular after the pump motor. It is also proposed that the discharge nozzle in a region lying downstream of the bypass nozzle, in particular after or in an area around the pump impeller, is arranged, finally, it is proposed for the first time that only the coolant, which through the suction nozzle for the inlet directly from Cooler can be sucked, in a sheath flow - by a, preferably from the outer wall of the pump motor housing and the facing inner wall of the pump housing and / or the facing inner wall of the directional valve limited flow channel - is fed past the pump motor, so that this and the other electronic and / or or electrical components can be optimally cooled.

In the case of the coolant pump according to the invention, in contrast to known electric coolant pumps with integrated directional valve, the direction of flow through the pump is reversed for the first time, ie the cooled coolant coming from the radiator, in particular a liquid coolant based on water, is supplied to the pump from the rear, so to speak. Thus, the cold, coming from the radiator coolant first flows past the pump motor, absorbs its waste heat and cools it down to allowable operating temperatures that are easily tolerated by the electric motor, before coming from the radiator coolant optionally with the supplied from the bypass circuit hot coolant mixed and this coolant mixture accelerated by the pump impeller or circulated through the discharge port to the vehicle engine off or is returned.

In this way, electronic components and / or electrical components in the coolant pump can advantageously be used whose temperature compatibility ends in a border region of approximately 115.degree. C. to 120.degree. Because of the maximum temperature of the coolant coming from the cooler of 113 ° C overheating of these components and / or components is excluded for the first time in principle.

Thus, even when operating a motor vehicle in hot areas, such as in the desert, due to the set by the automotive industry maximum radiator temperature sufficient heat dissipation guaranteed by the motor vehicle engine, without fear in the coolant pump exceeding the critical for some components temperature limit of 120 ° C. must, so that it is ultimately possible in an advantageous manner, even for the electric coolant pump to provide electronic components or electrical components in which not only at 120 ° C, the heat death threatens, but for example, only up to 115 ° C are reliably operated. This can be installed much cheaper electronic components.

The coolant pump according to the invention is also distinguished by its improved robustness, an extended field of application and significantly reduced production costs. The flow or coolant-cooled electric coolant pump according to the invention is an inexpensive and particularly reliable alternative to known solutions on the market.

Furthermore, larger or more powerful electric motors can be used for the first time. Although these often produce a higher heat load, which, however, can be removed easily due to the invention according to the invention always available on the electric motor cool coolant. The hitherto estimated in motor vehicle coolant pump construction as insurmountable power limit with a maximum power consumption of 500 watts at a battery voltage of 12 volts thus means for the first time no insurmountable barrier more.

Advantageous developments of the invention will become apparent from the features of the dependent claims.

In a preferred embodiment, it is provided that the coolant coming from the radiator circuit can be mixed with the coolant of the bypass circuit that can be sucked in by the bypass stub after the pump motor through the directional control valve. For this purpose, openable with the directional control valve and re-closable mouth of the bypass nozzle in an area upstream of the pump impeller is arranged so that the coolant mixture coming from the radiator cooled coolant and coming from the bypass heated coolant is accelerated or circulated together by the pump impeller can. It is provided in a further preferred embodiment that the mouth of the directional control valve is located in a region between the pump impeller and the downstream end of the flow channel.

This ensures that the cooled coolant coming from the radiator is completely or unmixed completely available to the pump motor for its cooling and optionally also for cooling further electrical and / or electronic components arranged in the region of the pump motor. In addition, it is further ensured that a heat input by the coming from the bypass circuit heated coolant in the coming from the radiator cooled down coolant only after the Kühlmittelpumpenelektromotor and thus a desired or requested by the engine management mixture temperature can be set or regulated targeted, without an optimal Affecting cooling of the pump motor.

In a further preferred embodiment it is provided that the pump motor and the pump shaft are arranged coaxially to the longitudinal axis of the pump housing. Although constructive alternatives are conceivable in which the pump shaft is arranged coaxially to the longitudinal axis of the pump motor, however, this assembly is arranged asymmetrically or eccentrically in the pump housing, which may possibly lead to cost advantages in the manufacture of the housing. Nevertheless, the concentric or coaxial variant is preferred because it builds much easier, due to the symmetries structurally easier to implement and fluidically provides the greatest benefits as well as probably the most cost-effective solution in terms of cost.

In a further preferred embodiment, it is provided that the flow channel, which is bounded by the outer wall of the motor housing comprising the pump motor and the facing inner wall of the pump housing, has an annular cross section. Through this annular flow channel is - starting from the pump impeller end remote from the pump motor - coolant, which is sucked cooled by the inlet from the radiator, in a ring surrounding the motor housing sheath flow on the pump motor vorbeiführbar. Thus, the heat generated by the electric motor is dissipated all around evenly in an advantageous manner. A point or partial surface occurring heating or even so-called "hot spots" are excluded. This ensures long-term reliable operation at temperatures compatible with the pump motor.

According to a further preferred embodiment, it is provided that the flow channel has a constant cross section in the flow direction. In this case, from the downstream end of the pump motor to the pump impeller, a constriction of the prevailing at the end of the flow channel diameter to the diameter of the discharge nozzle. Thus, a fluidically particularly favorable variant is specified. The cooler with the Coolant pump sucked cool coolant can flow past without any loss of flow at constant cross section of the pump motor, this optimally cool and then sucked through the constriction at the end of the flow channel, sucked by the pump impeller or fed to the discharge nozzle, thereby simultaneously through the constriction of a bundling of total volume flow to the pump impeller takes place and also takes place a fluidic acceleration of the coolant. Furthermore, pressure losses are avoided in an advantageous manner and unwanted turbulence is excluded.

In a further preferred embodiment, the directional control valve is continuously switchable from a closed position "Bypass-closed" to an open position "Bypass-open".

This will not only the benefits of already from the DE 102 07 653 used known 3/2-way valve, but these benefits are extended to the infinite controllability of the valve. Thus, any desired or required by the thermal management for the motor vehicle temperature mixing ratio of cool coolant and hot bypass coolant can be adjusted. The engine management or thermal management of the motor vehicle engine can thus actively set optimum operating conditions for the engine.

In a further preferred embodiment, the directional control valve is designed as a valve slide which is displaceable in the longitudinal direction of the coolant pump. In a particularly preferred embodiment, the valve slide is designed as a cylindrical sleeve. This can be made for example of metal. Alternatively, it is conceivable to form the valve slide also made of plastic or the like. In this case, plastics can be used, for example also be used for the production of Kühlmittelpumperigehäuses.

The coolant pump housing as the valve spool can be made particularly low, for example, in the plastic injection molding process. A reworking of these components is not necessary in an advantageous manner.

The equipped with a valve spool valve has the further advantage of a fail-safe position, so that the radiator access in case of failure of the valve is open in any case. In addition, it is characterized by the lowest possible, ideally going to zero differential pressure. At the valve spool thus continues to occur advantageously no pressure drop, which ultimately leads to the fact that for switching or actuation of the valve already meets a very low switching capacity.

This positive effect is exacerbated by the fact that the valve slide due to the coming to the main flow direction of coming from the radiator, the pump motor and the valve spool flowing past coolant parallel movement direction has particularly low friction or movement losses.

Another advantage of the valve spool is that it can be formed without any leakage. In contrast, leakage is never completely ruled out with rotary valves due to the moving transversely to the main flow direction parts.

In addition, the coolant pump according to the invention has the further advantage that a low pumping capacity already to achieve a desired Coolant flow rate is sufficient. This pump motors can be used with a low electrical power consumption.

In addition, the coolant pump according to the invention has the further advantage that occurs in the valve position "radiator open" no reduction of the maximum flow cross-section, so that even for this reason a low flow rate for the circulation of the coolant is sufficient, so that the electric pump therefore also with an im Compared to commercial electric pumps lower power consumption can be produced.

In a further preferred embodiment, the valve spool is actuated by an actuator, such as an electric actuating magnet, a Dehnstoffelement, a hydrostatic pressure element or the like, displaced by force. Such actuators are characterized by a very low tendency to wear, offer a long service life and particularly high switching cycles and are available at low cost. In addition, such actuators work extremely reliable and are largely störungsunanfällig.

According to a further preferred embodiment, the valve spool has a radially inwardly directed seal in the region of the supply of the coolant introduced from the bypass loop through the bypass spigot, which in the closed state of the directional control valve its mouth by a valve seat sealing against an annular sealing seat of the pump housing closes.

The seal may be, for example, an elastomeric seal. The ring-shaped seat support guarantees an absolutely tight closing. Secondary leaks are excluded. A constriction of the distribution paths, regardless of whether the directional control valve is now in the position "Bypass closed" or in the position "Bypass open" is excluded, even in intermediate positions. This is a special streamlined valve variant specified. In addition, a cylindrical sleeve can be particularly easily sealed in a cylindrical housing, so that secondary leaks are excluded for this reason.

Another advantage of the formed as a cylindrical sleeve valve slide is its relatively simple kinematics, so that a switching movement in the longitudinal direction is easily implemented. This offers the further advantage that a continuous mixture of bypass and inlet by a simple linear movement, namely a longitudinal displacement is realized, so that a direct, in particular linear, relationship between valve position or orifice and mixing ratio and current position of the valve spool consists Accordingly, control technology can be displayed easily or without special effort.

In a further preferred embodiment, the radially inwardly facing surface of the seal has a contour corresponding to the opposite contour of the motor housing. Thus, the coolant flow can flow optimally, in particular laminar, through the flow channel section formed in this case. Flow losses are avoided. Turbulence is excluded.

According to a further preferred embodiment, the solenoid actuating magnet of the valve slide has an armature which is formed by the cylindrical sleeve of the valve slide. Thus, the valve spool is used twice in an advantageous manner. On the one hand it is part of the valve and on the other hand it is at the same time a component of the solenoid solenoid. This helps to further reduce costs and increases reliability due to the reduced variety of parts. In this case, this dual function can be provided particularly favorable by a metal valve slide valve. Alternatively, an in Plastic executed valve spool area also have metallic sections that serve as anchors.

Accordingly, it is provided in a further preferred embodiment that the electric actuating magnet has a coil carrier arranged in the pump housing, which encloses the armature. The anchor formed by the valve sleeve can be completely enclosed by the coil carrier. The bobbin can thus optimally interact with the armature and move it already with low magnetic forces, so that so that the valve sleeve in the longitudinal direction relative to conventional valves can be relatively easily moved back and forth. In this case, the cylindrical valve sleeve can be guided sealed radially outward against the magnet with rod seals or the like, so that even at this point no secondary leakage can occur. Thus, a particularly inexpensive embodiment of a reliable, continuously variable directional valve variant is specified.

In a further preferred embodiment it is provided that downstream of the bypass nozzle and before the impeller, a return, for example, a heating circuit, a transmission oil heat exchanger, a lubricating oil heat exchanger, a separate cylinder block cooling circuit or the like, opens into the pump housing. Thus, further, the coolant circuit and the engine thermal management complementary secondary circuits can be detected by the electric coolant pump according to the invention and the coolant flowing there are supported by the coolant pump in an advantageous manner. In this case, such a return can be coupled without a valve directly to the pump housing or, if necessary, have a valve for its targeted control, in which case advantageously the above-discussed directional control valve can be used in an adapted form.

In a further preferred embodiment, the pump housing is constructed in two parts. This allows a simplified construction of the electric coolant pump. Their assembly is facilitated. It is provided in a further preferred embodiment that the electric actuating magnet in the longitudinal direction oriented coil contacts, which in an advantageous manner when joining the two housing parts via correlating contacts with a housed in the other housing part control device, such as a CPU, a control unit or the like, can be brought into contact. This additionally facilitates the assembly.

Not least is provided in a further preferred embodiment, that in addition to the drive of the pump impeller by the coolant pump electric motor arranged coaxially with the pump shaft outside the pump housing drive wheel is provided, which is coupled via a freewheel to the pump shaft. Thus, the coolant pump can be driven primarily mechanically via a lying outside of the pump housing pulley or the like. The pulley is decoupled via a freewheel from the pump shaft drive technology. At standstill and at low speeds, a low-cost motor can take over the pump drive at a constant speed. At higher speeds, the pulley then overtakes the electric motor. This also has the advantage that even in on-board networks with low electrical power, the coolant pump according to the invention can be used. This alternative is much cheaper than the expensive brushless drive motors. Ensuring the required basal metabolic pumping power is thus ensured even in case of failure of the electric motor.

Finally, it is provided in a further preferred embodiment that the directional control valve or its valve slide with a Dehnstoffelelement is hydraulically driven or switched.

For this purpose, it is provided that the expansion element is designed, for example, as a wax element whose volume change due to a change in prevailing in the passing coolant temperature to a volume change in an adjacent, separate transmission medium, for example, also usable as a coolant water / glycol mixture leads. This separate transmission medium is separated from the wax element, for example by a flexible membrane. The volume change in the transmission medium is transmitted via corresponding lines, connecting holes or connecting channels to a cylinder space of the valve spool, so that it can be hydraulically actuated. A restoring force can be applied to the valve spool with a spring or the like.

It is further provided in a preferred embodiment that the expansion element is formed from wax. Its melting point is around 85 ° C. Its temperature-dependent volume change can then be transmitted via a separate coolant and associated connecting lines to the hydraulically driven valve spool.

According to a further preferred embodiment, the expansion element formed from wax should be arranged in an area adjacent to the pressure port in the pump housing. In this case, it can adjoin the coolant flowing past by means of a metallic inner wall which is arranged radially inside the expansion element and which, for example, can be designed as a metallic cylinder jacket. The expansion element may be separated from the associated, separate coolant with a membrane arranged radially outside of it, such that a temperature-dependent volume change of the expansion element is transferable to the coolant. The separate coolant can in turn be moved over the connecting lines in a cylinder chamber of the thus hydraulically driven valve spool.

In procedural terms, the object is achieved by the features of claim 22.

In this case, a method for conveying coolant with a coolant pump for a coolant circuit of an automotive internal combustion engine having at least one radiator circuit and a bypass circuit is proposed. The method comprises the following steps: a) supplying the coolant from the radiator to the coolant pump through a suction port of the coolant pump housing, b) supplying the coolant from the bypass circuit to the coolant pump through a bypass port, c) returning the coolant from the coolant pump to the vehicle engine by a pressure port, d) circulating the coolant with a pump impeller driven by a coolant pump electric motor via a pump shaft, the motor flowing around the coolant, e) adjusting the mixing ratio of the coolant flows circulating through the coolant pump with a directional control valve integrated in the coolant pump housing.

In this case, it is proposed for the first time to supply the coolant coming from the radiator via the suction nozzle in the region of the pump impeller facing away from the pump motor, wherein the coolant coming from the bypass is supplied via the bypass nozzle in a region downstream of the suction nozzle, and wherein the coolant over the pressure port is led away in a lying downstream of the bypass nozzle area. In this case, only the through the suction port from the radiator conveyed forward coolant in a sheath flow, by a, in particular from the outer wall of the pump motor housing and the facing inner wall of the pump housing and / or the facing inner wall of the directional valve limited flow channel, is guided past the pump motor.

Thus, an effective and reliable cooling of the pump motor is possible in an advantageous manner. Furthermore, the advantages discussed above with the method are also achievable.

In the case of the coolant pump according to the invention, the temperature detection of the mixed coolant takes place in the pump housing outlet leading to the motor vehicle engine, that is to say in the region of the discharge nozzle. This ensures that the motor vehicle engine is always supplied with a sufficient amount of coolant in the required temperature. In this case, the amount and temperature of the coolant, which flows through the discharge nozzle to the engine depending on the temperature and amount of supplied by the bypass hot coolant, supplied by the inlet supplied by the radiator coolant, the amount of heat entered by the electric motor and, if necessary, a heating return or another return, such as supplied by a lubricating oil heat exchanger or a cylinder block cooling circuit heated further coolant. Accordingly, the CPU or control unit of the pump can deliver commands or voltage signals to the bobbin and the pump motor, so that the desired or required valve position is continuously adjusted and a requested engine speed is recorded. A correspondingly miniaturized or adapted variant of the slide valve can be used to control the return of a heater, a transmission oil heat exchanger or the like.

In the coolant pump according to the invention, the coolant pump housing is expanded by the valve function. Thus, the functionality of the coolant pump is increased and at the same time reduces the design effort, resulting in less effort during assembly and ultimately at a lower price. In this case, the split design of the housing also helps to reduce costs, since due to the housing division simpler assembly of the individual components is possible.

The pump impeller arranged downstream of the pump motor on the pump shaft in the flow direction has, for example, an impeller and a stator. The principle used here corresponds to the already proven principle of the axial pump, as it is successfully sold in the house of the applicant. The required, narrow running gap is processed in one setting, so that the necessary accuracy is ensured and post-processing is eliminated.

The control of the coolant pump according to the invention is designed so that even with a closed coolant circuit, ie at an open bypass circuit, no overheating of the electric motor threatens. The cooled coolant coming from the radiator is in the valve position "Bypass open" and "Radiator inlet closed" to the downstream end of the pump motor housing and encloses the pump motor or its housing. Thus, even at worst, at a maximum of 113 ° C., the coolant can still absorb a temperature interval of at least 7 ° C. of heat even in the worst case, until 120 ° C. has been reached and there is a threat of heat death of components. The control unit of the pump ensures that this case can not occur. Should this switch position threaten to overheat, the control unit ensures that the valve is briefly transferred to a position "inlet from the radiator open" and "by-pass closed", briefly the pending coolant flows and then the valve is returned to its original position, so that then again fresh, completely cooled down coolant from the radiator encloses the electric pump and cools. Accordingly, even with a cold start and while doing some time switch position "bypass open", which is chosen to keep the warm-up phase of the vehicle internal combustion engine as short as possible, no risk to the electronic components to be feared.

Due to the slide seat valve variant, all mixtures are possible. The slide seat valve can be adjusted continuously. There are no movement gaps that would be difficult to seal. The sealing ring, which may be an elastomeric sealing ring, for example, lies axially against the seal seat of the housing in the "bypass closed" position. Accordingly, the elastomer sealing ring sets in a reverse manner at a position "inlet closed by the radiator" against the housing of the electric motor sealingly. Movement gaps do not exist. Secondary leaks are excluded.

The solenoid is mounted opposite the valve sleeve with rod seals with Abstreiffunktion. This also excludes secondary leaks.

The valve sleeve, for example, spring biased or applied with alternative means with a basic force, so that in the case of a defect in the electronics, the valve automatically in a position "inlet from the radiator open" and "Bypass closed" passes. This ensures a fail-safe position, which ensures that the motor vehicle engine can not overheat.

The housing of the pump motor can be made of metal, for example of aluminum or another noble metal, which is particularly good heat-conducting. This ensures optimum heat dissipation from the electrically operated pump motor to the coolant flowing around it.

In the coolant pump variant preferred here, the bypass and the heating return in the non-temperature-critical region are supplied radially or tangentially from the outside to the pump center.

Fig. 1

in einer schematisch vereinfachten Skizze eine Zuordnung der Kühlkreisläufe mit beispielhaftem Einsatz der elektrischen Kühlmittelpumpe mit integriertem Wegeventil;

Fig. 2.

einen Längsschnitt durch eine beispielhafte Ausführungsform der Kühlmittelpumpe, mit dem Wegeventil in der Stellung "Bypass geschlossen" bzw. "Zulauf vom Kühler offen";

Fig. 3

die in Fig. 2 gezeigte Ausführungsform der Kühlmittelpumpe wiederum im Längsschnitt mit der Ventilstellung "Bypass teilweise offen" bzw. "Zulauf vom Kühler teilweise geschlossen";

Fig. 4

die in Fig. 2 und 3 gezeigte Kühlmittelpumpen-Variante mit der Ventilstellung "Zulauf vom Kühler geschlossen" bzw. "Bypass offen";

Fig. 5

einen Schnitt durch die in Fig. 4 gezeigte Kühlmittelpumpe längs der Schnittlinie B-B;

Fig. 6

eine 3D-Ansicht der in Fig. 2 bis 5 gezeigten Pumpe;

Fig. 7

einen Längsschnitt durch eine weitere Variante der Pumpe;

Fig. 8

eine 3D-Ansicht der weiteren Variante gemäß Fig. 7;

Fig. 9

eine weitere Variante der in Fig. 1 bis 8 gezeigten Kühlmittelpumpe mit einer Betätigung des Wegeventils durch ein Dehnstoffelement, im Längsschnitt dargestellt;

Fig. 10

ein vergrößerter Ausschnitt des in Fig. 9 gezeigten Längsschnitts entlang der dortigen Schnittlinie A-A; und

Fig. 11

eine dreidimensionale Ansicht dieser Kühlmittelpumpenvariante von außen.

The invention described above is explained in more detail in exemplary embodiments with reference to the figures of the drawing. It shows:

Fig. 1

in a schematically simplified sketch, an assignment of the cooling circuits with exemplary use of the electric coolant pump with integrated directional control valve;

Fig. 2.

a longitudinal section through an exemplary embodiment of the coolant pump, with the directional control valve in the position "Bypass closed" or "inlet from the radiator open";

Fig. 3

the embodiment of the coolant pump shown in Figure 2 again in longitudinal section with the valve position "bypass partially open" or "inlet from the radiator partially closed".

Fig. 4

the coolant pump variant shown in Figures 2 and 3 with the valve position "inlet closed by the radiator" or "bypass open".

Fig. 5

a section through the coolant pump shown in Figure 4 along the section line BB.

Fig. 6

a 3D view of the pump shown in Figures 2 to 5;

Fig. 7

a longitudinal section through a further variant of the pump;

Fig. 8

a 3D view of the further variant of FIG. 7;

Fig. 9

a further variant of the coolant pump shown in Figures 1 to 8 with an actuation of the directional control valve by an expansion element, shown in longitudinal section.

Fig. 10

an enlarged section of the longitudinal section shown in Figure 9 along the section line AA there. and

Fig. 11

a three-dimensional view of this coolant pump variant from the outside.

In Fig. 1, an exemplary assignment of circuits circuit diagram in a motor vehicle engine thermal management with the above-discussed coolant pump is shown in a simplified schematic representation. The electric coolant pump 1 is integrated in a coolant circuit 2. The coolant circuit 2 has a cooler circuit 4, which runs over a cooler 6. Furthermore, the coolant circuit 2 has a short circuit or bypass circuit 8, which closes the motor 10 directly to the coolant pump 1 short. Furthermore, by way of example, a heating circuit 12 from the engine 10 via a heater 13 to the electric coolant pump 1 back to the engine 10 is shown. Other secondary circuits, such as a coolant secondary circuit for a transmission oil heat exchanger for a lubricating oil heat exchanger, a separate cylinder head and a separate engine block cycle or the like are conceivable, but not shown here.

The electric coolant pump 1 with integrated directional control valve conveys the coolant sucked in by the engine 10 in the cooler circuit 4 via the radiator 6 back to the engine 10 or circulates it. Further, the coolant pump 1 promotes the circulating in the short-circuit 8 coolant. Last but not least, the coolant pump 1 also circulates the circulating coolant in the heating circuit 12.

The electrical coolant pump 1 with integrated directional control valve shown schematically in FIG. 1 with a symbol is explained in further detail in FIGS. 2 to 8 in various variants.

FIG. 2 shows a first exemplary embodiment of a coolant pump 1 in longitudinal section. The coolant pump housing 14 is divided into two in this embodiment. It consists of a first housing part 16 and a second housing part 18. Both housing parts 16 and 18 with an annular clip, clamp or clamp 20 firmly together, tightly connected. The housing 14 can also be made in three or more parts or even in one piece with a lid.

The coolant KZK coming from the cooler 6 in the cooler circuit 4 is fed to the pump housing 14 via the suction nozzle 22. This is symbolized by the arrow ZK pointing from the cooler 6 to the pump housing 14.

The from the bypass or short circuit 8 via the symbolized by an arrow inlet ZB, heated by the motor vehicle engine 10 coolant is supplied to the pump housing 14 via the bypass port 24.

In the coolant pump housing 14, a coolant pump electric motor 26 is arranged. Whose motor housing 28 is flowed around to cool the electric motor 26 from flowing past coolant. The pump motor 26 drives a pump impeller 32 via a pump shaft 30. In the variant shown here, the pump impeller 32, the pump shaft 30 and the pump motor 26 are arranged coaxially with the longitudinal axis X of the pump housing 14.

The coolant accelerated or circulated by the pump impeller 32 is conveyed away through a discharge nozzle 34 for the supply ZM of the coolant to the motor vehicle engine 10 symbolized with a further arrow.

In the illustrated embodiment, the coolant pump 1 in addition to the impeller 32 on a likewise arranged in the discharge nozzle 34 stator 36.

Furthermore, by way of example, a heating return 38 is shown, through which the supply ZH of the coolant from the heating circuit 12, symbolized in turn by an arrow, is possible for its circulation by the pump 1.

In the coolant pump housing 14, a continuously adjustable directional control valve 40 is integrated. The directional control valve can assume the position "bypass closed" or "supply from the radiator open" shown here in FIG. It can steplessly from this position on a position "bypass partially open" and "supply from the radiator partially open" (see Fig. 3) to a position "bypass open" or "supply from the radiator closed" (see FIG 4) and returned.

The suction nozzle 22 is arranged in an upstream region 42, which is located in the region of the end remote from the pump impeller 32 end 44 of the pump motor 26. The bypass nozzle 24 is further arranged in a region 46 located downstream of the suction nozzle 22. Furthermore, the discharge nozzle 34 is arranged in a region 48 located downstream of the bypass nozzle 24.

This ensures that only the coolant KZK, which is sucked in by the suction port inlet ZK from the radiator 6, is guided in a sheath flow 50 past the pump motor 26. The jacket flow 50 is thereby bounded firstly on the one hand by the outer wall 52 of the pump motor housing 28 and on the other hand by the facing inner wall 54 of the pump housing 14 to form a flow channel 56. The flow channel 56 is then radially outwardly through the outer wall 52 of the pump motor housing 28 facing inner wall or inner surface 60 of the directional valve 40 is limited, which adjoins the housing inner wall 54 in the flow direction in the region of the connection point of the two housing parts 16 and 18.

The exemplary embodiment of a flow-cooled electric coolant pump 1 with integrated directional control valve 40 shown in longitudinal section in FIG. 2 is again shown in longitudinal section in FIGS. 3 and 4, FIG. 3 showing a partially open position of the directional control valve 40 and FIG Directional valve 40 shows in which the inlet of the radiator ZK closed and the inlet of the bypass ZB is fully open.

The circulating with the coolant pump 1, coming from the radiator circuit 4 coolant KZK is mixed with the hinzuförderten by the bypass port 24 coolant KZB, which comes from the bypass circuit 8, through the directional control valve 40. Here, an openable with the directional control valve 40 and reclosable mouth 62 of the bypass port 24 in the region 46 upstream of the pump impeller 32 is arranged.

In the variant shown here, the mouth 62 is located between the pump impeller 32 and between the heating return 38 and the downstream end 64 of the flow channel 56th

As is clearer from FIG. 5, the inlet ZB from the bypass circuit 8 and the inlet ZH from the heating circuit 12 are arranged in the same plane, coaxial to the Y-axis, opposite to the longitudinal axis X extending perpendicular to the image plane. Alternatively, the corresponding nozzle can also be connected tangentially to the housing 14. This is primarily dependent on the available in the engine compartment for the pump 1 installation space and the position of the inlets and outlets.

Furthermore, it can be seen particularly well from Fig. 5 in conjunction with Fig. 2 to 4, that in the variant shown here, the pump motor 26, the pump shaft 30, the Pump impeller 32, the stator 36 and the pump housing 14 are arranged coaxially with each other to the longitudinal axis X.

The flow channel 56 delimited by the inner wall 54 of the pump housing 14 and / or by the inner wall 60 of the directional valve 40 on the one hand and on the other hand by the outer wall 52 of the pump motor 26 is annular in a particularly preferred embodiment or has an annular cross section. Thus, a motor housing 28 annularly enclosing sheath flow 56 is defined, which flows past the pump motor 26 and this optimally cools.

The flow channel 56 has a cross section 66 which is constant in the flow direction. From the downstream end 64 of the flow channel 56 and from the downstream end 68 of the pump motor 26 to the pump impeller 32 is a continuous or continuous constriction of the prevailing at the end of the flow channel 56 diameter up to the inner diameter 70 of the discharge nozzle 34th

The directional control valve 40 is designed as a valve slide 72, which is displaceable in the longitudinal direction X of the coolant pump 1 and, in the variant represented here, is configured as a cylindrical sleeve. The valve spool 72 is biased by a spring 73 or other suitable force-generating element so that in the event of valve control failure, the directional valve 40 is automatically transferred by the spring force of the spring 73 to a fail-safe position "inlet from the radiator open".

The valve spool 72 is used in addition to its valve function at the same time as an armature 74 of the valve spool 72 actuated Elektrostellmagneten 76. The valve spool 72 is on its radially outer side by means of Rod seals 77 with Abstreiffunktion performed and against the housing. 14 or sealed against the other adjacent components.

The solenoid actuator 76 has the aforementioned armature 74 and a coil support 78 arranged in the pump housing 14, which surrounds the armature 74. The armature 74 is formed in the manner of the cylindrical sleeve 72, that it is made of metal. The sleeve 72 can also be made of plastic and have the armature 74 forming metallic sections. On the bobbin 78, the associated coil 80 is arranged. The coil 80 is in turn surrounded by a radially outwardly of the coil 80 arranged iron yoke 82. Radial inside is an arranged between the coil support 78 and the armature 74, annular trained further iron yoke 84 integrated with characteristic influencing. The rod seals 77 are also arranged between the coil carrier 78 and the valve slide 72 formed as an armature 74, wherein a rod seal 77 connects directly to the iron yoke 84.

The valve spool 72 has a radially inwardly directed seal 86 in the region of the bypass nozzle 24. The seal 86 may be formed as an elastomeric seal. Other seal materials are also usable. The seal 86 closes in a closed position "Bypass closed" of the directional control valve 40 with its annular flat face 88, the surface normal parallel to the longitudinal axis X, sealingly seals against a correspondingly formed annular seal seat 90 of the pump housing 14. In an open position "Bypass open" which accordingly can also be referred to as "inlet closed by the radiator" closes the seal 86 with its radially inwardly facing annular tip 92 the inlet from the radiator ZK at the end 68 of the electric motor 26 and at the end 64 of the flow channel 56 against the motor housing 28 and a subsequent pump shaft housing 94 tightly. Alternatively to the seal 86 are also other seal variants conceivable, with which in the axial direction dense completion of the directional valve 40 against the housing 14 and with which in the radial direction a tight completion of the directional control valve 40 against the pump shaft housing 94 or the pump motor housing 28 is possible. Such seals 86 may also include more than one seal seat or one or more seal lips or the like.

The electric actuating magnet 76 has coil contacts 96 oriented in the longitudinal direction X or parallel to the X-axis. These coil contacts 96 correlate with corresponding contacts 98 of an integrated electronic component in the housing part 18, such as a control device 100, a CPU or the like, so that the control device 100 and the Elektrostellmagnet 76 directly during assembly of the two housing parts 16 and 18 without further action can be brought into contact. In the housing part 18, an amplifier unit 102 is further accommodated. This can be connected from the outside by a plug 104 to corresponding control circuits.

The exemplary embodiment of a coolant pump 1 illustrated in FIGS. 2 to 5 is illustrated in FIG. 6 in a three-dimensional view for a better understanding of the spatial allocation of the connecting piece or components.

FIGS. 7 and 8 show a further exemplary embodiment of a coolant pump 1. The same or equivalent components are provided with the same reference numerals, as used in Fig. 2 to 5 used.

The coolant pump 1 shown in FIG. 7 has, in addition to the drive of the pump impeller 32 in addition to the coolant electric motor 26, a drive wheel 106 arranged outside the pump housing 14. The drive gear 106 is aligned coaxially with the pump shaft 30 and mechanically couplable to the pump shaft 30 via a freewheel 108. The pump shaft 30 has an additional one Bearing 110 in the right-hand end of the housing part 18 in this illustration. About the drive gear 106, the impeller 32 can be driven in addition to the electric motor 26 from the outside, for example via a belt or a pinion. Thus, the coolant pump 1 can be driven primarily mechanically via the example formed as a pulley drive wheel 106. The drive wheel 106 is decoupled via the freewheel 110 from the pump shaft 30 for this purpose. At standstill and at low speeds of the internal combustion engine, for example, takes a low-cost electric motor pump drive at a constant speed. At higher speeds of the internal combustion engine, the drive wheel 106 overtakes the electric motor. This pump variant can also be used in electrical systems with low electrical power. It represents a cost-effective alternative to expensive brushless drive motors. A pumping capacity is ensured even in the event of a failure of the electric motor.

The variant of the coolant pump 1 shown in longitudinal section in FIG. 7 is illustrated in FIG. 8 in a three-dimensional view for a better understanding of the spatial allocation of the components.

FIGS. 9 to 11 show a further variant of a coolant pump 1. The further variant of a coolant pump 1 shown in FIG. 9 in longitudinal section and in FIG. 10 in an enlarged detail and in FIG. 11 in three-dimensional view corresponds structurally essentially to the coolant pump 1 discussed in FIGS. 1 to 6 or equivalent components are provided for simplicity with the same reference numerals.

The exemplary modifications shown in FIGS. 9 to 11 with regard to the driving of the directional control valve 40 in more detail here via an expansion element 112 can also be correspondingly transferred to the coolant pump variants shown in FIGS. 1 to 6 as well as in the coolant pump variants shown in FIGS.

The alternative shown in FIGS. 9 to 11 of a drive of the directional control valve 40 via an expansion element 112 makes use of the volume change of the expansion element 112 as a function of the temperature prevailing in the pressure connection 34 of the coolant mixture flowing therethrough. As expansion element 112 comes in the variant shown here, for example, wax used. The wax used here has a melting point at about 85 ° C. The wax is present as wax element 112 solidified in the cold state. The wax element 112 is spatially close to the pump outlet or the discharge port 34 or adjacent. It learns by the demarcation against the passing coolant flowing metallic inner shell 114 any temperature change in the coolant flowing to the engine ZM directly. Temperature influences from the outside are prevented by the insulating effect of the pump housing 14 made of plastic. When heating or cooling of the expansion element 112 formed from wax, the resulting change in volume is transmitted via a membrane 116 to a stored in a reservoir 118 transmission medium or coolant 120. The coolant 120 may be, for example, a water / glycol mixture.

Via connecting bores 122 and 124, the resulting difference volume passes into a cylinder chamber 126 of the valve spool 72 of the directional valve 40. Thus, a hydraulic path ratio is realized. The expansion of the wax 112 by curvature of the diaphragm 116 from the reservoir 118 to the cylinder chamber 126 flowing coolant 120 - or corresponding to cooling of the wax 112 from the cylinder chamber 126 back to the reservoir 118 flowing coolant 120 - causes a shift of the valve spool 72 of the directional control valve 40 in a direction parallel to the longitudinal axis X of the coolant pump. 1

The spiral spring 73 shown in the embodiments of FIGS. 1 to 8, which provided there to ensure a fail-safe position of the directional valve 40 is now used to achieve a closing function in the directional control valve variant shown here, and no longer used to create a fail-safe position. As shown in Fig. 9 and 10, the valve spool 72 is in the relaxed state of the spring 127 in a position "bypass open" or "cooler inlet closed" before. Accordingly, heating the expansion element 112 made in wax and the resulting volume expansion of the wax leads to a curvature of the membrane 116 and thus to a change in the volume of the reservoir 118, which ultimately results in a displacement of coolant 120 from the reservoir 118 into the cylinder chamber 126. This displacement of coolant 120 into the cylinder chamber 126 causes a force which acts against the spring force of the spring 127 and thus shifts the valve spool 72 to a "bypass closed" or "radiator inlet open" position. The spring 127 accordingly provides for cooling the expansion element 112 for the required return stroke of the valve spool 72. Since it is a closed system, this process is arbitrarily repeatable.

The drive of the directional control valve 40 via an expansion element 112 offers the additional advantage over an electromagnetic drive that considerable weight can be saved. For a drive of the directional control valve 40 via an electromagnet 76, as illustrated in Figures 1 to 8, means additional weight by the electromagnet 76. Here, the light expansion element 112 in conjunction with the designed for a hydraulic drive valve slide 72 its weight and partially also play some cost advantages.

In addition, it is possible to assign the expansion element 112 not shown here cooling and / or heating elements. This can, possibly using the existing control device or CPU 100, corresponding temperature sensors and possibly control circuits or the like, active on the volume expansion of the expansion element 112 to adjust, if necessary, other control states of the directional valve 40, than those that would arise by itself.

The coolant 120 can be introduced into the storage chamber 118 or into the system by means of a filling opening 130 which can be closed by a screw plug 128. The running in wax expansion element 112 is so dimensionally stable in a cold state that it can be installed as a finished component when assembling the pump 1 with the same. Sealing rings 132 or the like serve to seal the valve spool 72 against the housing 14.

FIG. 10 shows particularly clearly how the spring 127 forms a force pair with the expansion element 112 via the transmission medium 120 and generates a permanent counterforce to the expansion element 112. For the expansion element 112 commercial wax wax can be used. The transfer medium or coolant 120 may be a water / glycol mixture. The filled with coolant 120 storage space 118, connecting lines 122 and 124 and cylinder chamber 126 formed hydraulic system 134 is filled bubble-free with overpressure during assembly of the coolant pump. The expansion element 112 formed of wax is inserted during assembly of the pump 1 in the housing 14, in the space 136 of the metallic cylinder jacket 114, which limits the radial clearance of the impeller 32 and the inner wall of the elastomeric membrane 116, that is hermetically delimited. The wax has a melting point of about 85 ° C. Influence of the wax 112 is possible in principle via a heating and / or a cooling element.

The variant of the coolant pump 1 shown in longitudinal section in FIG. 9 and in an enlarged partial section in FIG. 10 is illustrated in FIG. 11 in a three-dimensional view for a better understanding of the spatial allocation of the components.

The structural design of the wax element is matched to the structural conditions of the coolant pump. The with the expansion element ultimately hydraulically driven directional control valve acts advantageously similar to an electrically adjustable thermostat. The components of a vehicle that have an impact on fuel consumption and emissions are the focus of attention today. A map-controlled thermostat is a component that has a positive influence on the fuel consumption and the reduction of the emission. Conventional thermostats are set to a fixed opening temperature that can not be changed. With an electrically controllable map thermostat, the opening temperature of a valve can be varied depending on various parameters, e.g. Load, rotational speed, ignition angle, outside temperature, engine oil temperature, driving speed, etc. These advantages are also achieved with the electromagnetic valve or hydraulically operated via a Dehnstoffelement directional control valve of the coolant pump according to the invention.

The wax element may optionally be additionally heated or cooled. For heating a non-illustrated rod heater can be used. This takes over the heating of the wax element while it is in direct contact with the wax. The heating of the rod heater can be done for example via a coiled on a ceramic body resistance wire. Unheated so that the thus formed thermostat can be set for example to a temperature of 110 ° C. By heating the temperature can be lowered, for example, to about 70 ° C. The full opening temperature is thus reached at 15 ° C above the normal opening temperature. The reaction time of the thermostat can be influenced by heating power, immersion depth of the rod heater in the wax element, and the surface design of the wax element.

In order to be able to test the aforementioned application in the development phase, an electronics unit was developed by the applicant. This makes it possible to process all input variables used in engine management. By means of corresponding links, the required outputs, for example via appropriate control circuits, the control device or CPU 100 or the like, are subsequently activated. The links are freely programmable depending on the internal combustion engine. In series production, the program can then be stored, for example, in the engine electronics of the respective internal combustion engine. A separate electronics is not required.

The present invention provides for the first time a coolant pump for a coolant circuit of an automotive internal combustion engine having at least one radiator circuit and a bypass circuit. The coolant pump housing has a suction nozzle, a bypass nozzle and a discharge nozzle, and arranged in the coolant pump housing coolant pump electric motor, the motor housing is flowed around by the coolant, and drives a pump impeller via a pump shaft, as well as an integrated in the coolant pump housing directional control valve. The suction nozzle is for the first time arranged in the region of the pump impeller facing away from the end of the pump motor. The bypass nozzle is further arranged in a region downstream of the suction nozzle. The discharge nozzle is arranged in a region downstream of the bypass nozzle. Only the coolant, which can be sucked in by the suction port inlet from the cooler, should be able to be guided past the pump motor in a sheath flow, through a flow channel bounded by the outer wall of the pump motor housing and the facing inner wall of the pump housing and / or the facing inner wall of the directional control valve.

LIST OF REFERENCE NUMBERS

1

Coolant pump

2

Coolant circuit

4

cooler Closed

6

cooler

8th

Bypass circuit

10

engine

12

Heating circuit

13

heater

14

pump housing

16

First housing part

18

Second housing part

20

Clasp, clamp or clip

22

suction

24

Bypass pipe

26

Coolant pump electric motor

28

motor housing

30

pump shaft

32

pump impeller

34

pressure port

36

stator

38

Heating return

40

way valve

42

Area, lying upstream

44

upstream end of the pump motor

46

Area, lying downstream of the suction nozzle

48

Area, lying downstream of the bypass spigot

50

Mantelsrömung

52

Outer wall of the pump motor

54

Inner wall of the pump housing

56

flow channel

58

60

Inner wall of the directional control valve

62

Mouth of the bypass

64

downstream end of the flow channel

66

Cross section of the flow channel

68

downstream end of the pump motor housing

70

Inner diameter of the discharge nozzle

72

Directional valve, designed as a valve spool

73

spiral spring

74

Valve slide also designed as an anchor of the solenoid

76

Operating solenoid

78

Coil carrier of the solenoid actuator

80

Coil of the solenoid

82

Iron yoke, radially outside coil, selbige comprising

84

Iron yoke with characteristic influencing, between coil and armature

86

Seal made of elastomer

88

face

90

Seal seat, in the pump housing

92

radially inward facing sealing tip

94

Pump shaft housing

96

Coil contacts, oriented axially or parallel to the X-axis

100

Control device or CPU

102

amplifier unit

104

plug

106

drive wheel

108

freewheel

110

shaft bearing

112

Expansion element, executed in wax

114

metallic inner jacket

116

membrane

118

Storage volume / pantry

120

coolant

122

connecting bore

124

connecting bore

126

cylinder space

127

feather

128

Screw

130

filling

132

seals

134

hydraulic system

136

gap

Claims (22)

1. A coolant pump (1) for a coolant circuit (2) of an automotive internal combustion engine (10) including at least a radiator circuit (4) and a bypass circuit (8), which comprises:

   - a coolant pump housing (14) having an intake pipe (22) for the supply (ZK) from the radiator (6), a bypass pipe (24) for the supply (ZB) from the bypass circuit (8), and a pressure pipe (34) for the supply (ZM) of coolant to the automotive vehicle engine (10),

   - a coolant pump electric motor (26) arranged in the coolant pump housing (14), the motor housing (28) of which is situated in the coolant flow, and which drives a pump impeller (32) through the intermediary of a pump shaft (30), and

   - a directional control valve (40) integrated into the coolant pump housing (14),

   characterized in that

   - the intake pipe (22) is arranged in the area (42) of the end (44) of the pump motor (26) facing away from the pump impeller (32),

   - the bypass pipe (24) is arranged in an area (42) situated downstream of the intake pipe (22),

   - the pressure pipe (34) is arranged in an area (42) situated downstream of the bypass pipe (24), and

   - only the coolant (KZK) that can be taken in by the intake pipe (22) as a supply (ZK) from the radiator (6) may be taken past the pump motor (26) in a peripheral flow (50) through a flow channel (56) preferentially defined by the outer wall (52) of the pump motor housing (28) and the facing inner wall (54) of the pump housing (14) and/or the facing inner wall (60) of the directional control valve (40).
2. The coolant pump (1) in accordance with claim 1, characterized in that the coolant (KZB) of the bypass circuit (8) that may be taken in through the bypass pipe (24) may be admixed to the coolant (KZK) arriving from the radiator circuit (4) with the aid of the directional control valve (40), wherein an outlet (62) of the bypass pipe (24) adapted to be opened and closed again with the aid of the directional control valve (40) is disposed in an area (42) upstream of the pump impeller (32).
3. The coolant pump (1) in accordance with claim 2, characterized in that the outlet (62) of the directional control valve (40) is disposed in an area (42) between the pump impeller (32) and the downstream end (64) of the flow channel (56).
4. The coolant pump (1) in accordance with any one of claims 1 to 3, characterized in that the pump motor (26) and the pump shaft (30) are arranged coaxially with the longitudinal axis X of the pump housing (14).
5. The coolant pump (1) in accordance with any one of claims 1 to 4, characterized in that the flow channel (56) defined by the outer wall (52) of the motor housing (28) enclosing the pump motor (26) and the facing inner wall (54) of the pump housing (14) and/or the facing inner wall (60) of the directional control valve (40) has an annular cross-section through which the coolant (KZK) that can be taken in through the intake pipe (22) for the supply (ZK) from the radiator (6) may be taken past the pump motor (26) in a peripheral flow (56) annularly enclosing the motor housing (28).
6. The coolant pump (1) in accordance with any one of claims 1 to 5, characterized in that the flow channel (56) has a cross-section (66) that is constant in the direction of flow, wherein a constriction from the diameter present at the end of the flow channel (56) to the inner diameter (70) of the pressure pipe (34) takes place from the downstream end (68) of the pump motor (26) to the pump impeller (32).
7. The coolant pump (1) in accordance with any one of claims 1 to 6, characterized in that the directional control valve (40) may be switched continuously from a closed position of "bypass closed" into an open position of "bypass open."
8. The coolant pump (1) in accordance with any one of claims 1 to 7, characterized in that the directional control valve (40) has the form of a valve spool (72) slidingly displaceable in the longitudinal direction X of the coolant pump (1).
9. The coolant pump (1) in accordance with claim 8, characterized in that the valve spool has the form of a cylindrical sleeve (72).
10. The coolant pump (1) in accordance with any one of claims 8 or 9, characterized in that the valve spool (72) may be displaced by an actuator such as, e.g., an operating solenoid (76), a thermally expandable element (112), a hydrostatic pressure member, etc.
11. The coolant pump (1) in accordance with any one of claims 8 to 10, characterized in that the valve spool (72) has downstream in the area of the outlet (62) a radially inner, annular peripheral seal (86), which in the closed postion, "bypass closed", of the directional control valve (40) sealingly closes the outlet (62) thereof by means of an end face (88) against an annular seal seat (90) of the pump housing (14), and/or in the open condition, "bypass open", sealingly closes the flow channel (56) by means of a radially inwardly directed seal lip (92) against the pump motor housing (28) or the pump shaft housing (94).
12. The coolant pump (1) in accordance with claim 11, characterized in that the radially inwardly directed surface of the seal (86) has a contour corresponding to the opposite contour of the motor housing (28) or of the pump shaft housing (94).
13. The coolant pump (1) in accordance with any one of claims 8 to 12, characterized in that the operating solenoid (76) of the valve spool (72) includes an armature (74) formed by the cylindrical sleeve of the valve spool (72).
14. The coolant pump (1) in accordance with claim 13, characterized in that the operating solenoid (76) includes a coil carrier (78) arranged in the pump housing (14) and enclosing the armature (74).
15. The coolant pump (1) in accordance with any one of claims 1 to 14, characterized in that downstream following the bypass pipe (24) and still upstream of the pump impeller (32), a return flow (38), e.g. for a heating circuit, a transmission oil heat exchanger, a lubricant oil heat exchanger, a cylinder block cooling circuit or the like, merges into the pump housing (14).
16. The coolant pump (1) in accordance with any one of claims 1 to 15, characterized in that the pump housing (14) is constructed in two parts (16, 18).
17. The coolant pump (1) in accordance with any one of claims 1 to 16, characterized in that the operating solenoid (76) has coil terminals (96) oriented in the longitudinal direction X, which may by means of correlating terminals (98) be taken into contact with control means (100) accommodated in the other housing part (18) such as a CPU etc., upon joining together the two housing parts (16, 18).
18. The coolant pump (1) in accordance with any one of claims 1 to 17, characterized in that in addition to driving the pump impeller (32) by the coolant pump electric motor (26), a drive wheel (106) is provided which is arranged coaxially with the pump shaft (30) externally of the pump housing (14) and coupled to the pump shaft (30) via a free-wheel (108).
19. The coolant pump (1) in accordance with any one of claims 1 to 18, characterized in that the thermally expandable element (112) is in operative connection with the directional control valve (40) via connection lines (122, 124) such that the directional control valve (40) may be switched hydraulically through a volume change of the thermally expandable element (112).
20. The coolant pump (1) in accordance with any one of claims 1 to 19, characterized in that the thermally expandable element (112) is formed of wax, the temperature-dependent volume change of which may be transferred to the hydraulically actuatable valve spool (72) via a separate coolant (120) and connection lines (122, 124).
21. The coolant pump (1) in accordance with any one of claims 1 to 20, characterized in that the thermally expandable element (112) formed of wax is arranged in an area adjacent the pressure pipe (34) in the pump housing (14) and is separated from the associated, separate coolant (120) through a diaphragm (116), such that a temperature-dependent volume change of the thermally expandable element (112) may be transferred to the coolant (120), which in turn may be displaced via the connection lines (122, 124) into a cylinder chamber (126) of the valve spool (72) thus adapted to be actuated hydraulically.
22. A method for conveying coolant by means of a coolant pump (1) for a coolant circuit (2) of an automotive internal combustion engine (10) comprising at least a radiator circuit (4) and a bypass circuit (8), comprising the steps:

    - supplying the coolant from the radiator (6) to the coolant pump (1) through an intake pipe (22) of the coolant pump housing (14) for the supply (ZK),

    - supplying the coolant from the bypass circuit (8) to the coolant pump (1) of the coolant pump housing (14) through a bypass pipe (24) for the supply (ZB),

    - returning the coolant from the coolant pump (1) to the automotive vehicle engine (10) through a pressure pipe (34) for the coolant return (ZM),

    - circulating the coolant (1) by means of a pump impeller (32) arranged in the coolant pump housing (14) and driven by a coolant pump electric motor (26) via a pump shaft (30), wherein the engine (26) is situated in a flow of the coolant,

    - adjusting the mixing ratio of the coolant flows circulating through the coolant pump by means of a directional control valve (40) integrated into the coolant pump housing (14),

    characterized in that

    - the coolant arriving from the radiator (6) is supplied via the intake pipe (22) in the area (42) of the end (44) of the pump motor (26) facing away from the pump impeller (32),

    - the coolant arriving from the bypass is supplied via the bypass pipe (24) in an area (42) located downstream of the intake pipe (22),

    - the coolant is taken away via the pressure pipe (34) in an area (42) located downstream of the bypass pipe (24), and

    - only the coolant (KZK) supplied from the radiator (6) through the intake pipe (22) as a supply (ZK) is taken in a peripheral flow (50) past the pump motor (26) through a flow channel (56) preferentially defined by the outer wall (52) of the pump motor housing (28) and the facing inner wall (54) of the pump housing (14) and/or the facing inner wall (60) of the directional control valve (40).

Images