CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims priority to German patent application No. 102018219949.3, filed on Nov. 21, 2018. The entire contents of the above-listed application is hereby incorporated by reference for all purposes.

FIELD

The present description relates generally to a control valve for controlling a coolant circuit for a charge-air cooler.

BACKGROUND/SUMMARY

Internal combustion engine systems may be equipped with a turbocharger in order to increase the efficiency of the internal combustion engine. To further increase efficiency, the charge air compressed by a compressor of the turbocharger may be cooled, because charge air warmed as a result of the compression demands a larger volume and thus has a lower density than cooled air. In this context, charge-air cooling systems are known which cool the charge air without an additional cooling system directly at the vehicle front end, for example via an air/air heat exchanger. Alternatively or in addition, the charge-air coolers may be connected to a coolant circuit. The coolant circuit will also be referred to as low-temperature coolant circuit relative to a high-temperature coolant circuit, which cools the engine and other hotter components.

The low-temperature coolant circuit may be configured as a separate cooling system and is not connected to the high-temperature coolant circuit. The two circuits may be equipped with individual heat exchangers and separate water pumps. In some cases, a common expansion tank is used. The individual coolant pumps may be controlled separately in order to attain the desired functionality under different operating conditions. Examples of corresponding coolant circuits are disclosed in the documents US 2012/0018127 A1 and U.S. Pat. No. 9,709,065 B2.

It is an object of the present disclosure to further improve the described coolant circuits, in particular with regard to disadvantages that arise from the separation of the low-temperature coolant circuit and the high-temperature coolant circuit, for example with regard to costs, weight and stowage space.

The issues described above may be at least partially solved by a control valve according to the disclosure, wherein the control valve is configured for controlling the flow of a first fluid medium. Said control valve comprises a housing which comprises a flow channel for the fluid medium with an inlet and an outlet. The control valve furthermore comprises a closure for at least partially opening and closing the flow channel. The control valve furthermore comprises an access for at least one second fluid medium, wherein the closure is designed to be moved in the flow channel for the first fluid medium by the pressure of the second fluid medium, and a thermostat with a connection in terms of flow to the flow channel for the first fluid medium. The thermostat is arranged between the closure and the outlet. The control valve comprises a first spring, which is arranged between the closure and the thermostat. The control valve furthermore comprises a second spring, which is arranged between the thermostat and the outlet and which holds the first spring in a stop position. The closure can be moved counter to the pressure of the first spring by the pressure of the second fluid medium. The thermostat is configured to control the opening characteristic curve of the closure, such that the closure closes the flow channel of the first fluid medium in a first working state and at least partially opens said flow channel in a second working state. Here, the second spring can be pushed together or compressed, wherein the position of the stop and, here, the preload of the first spring can be controlled.

The control valve according to the disclosure has the advantage that it is controlled simultaneously by the pressure of the first fluid medium, by the pressure of the second fluid medium, and by the temperature of the first fluid medium, in one example. The first fluid medium may be a coolant of a high-temperature coolant circuit for a charge-air cooler for an internal combustion engine of a vehicle. The access for the second fluid medium advantageously has a connection in terms of flow to an intake tract of an internal combustion engine. This has the advantage that the control valve can be controlled via the charge pressure.

In a further variant, the control valve is configured to detect the temperature of the first fluid medium via the thermostat. Here, the closure may be configured such that, in the first working state, that is to say in the closed state, the inlet is connected in terms of flow to the thermostat, such that a fraction of the first fluid medium can flow to the thermostat. This may be realized for example by virtue of a leakage flow opening being provided. Alternatively, a bypass flow channel may be provided, as illustrated by dashed line69. In one example, the dashed line69illustrates a bleed line69fluidly coupling the control valve inlet to the thermostat. The possibility of detecting the temperature of the first fluid medium via the thermostat has the advantage that the control valve can be controlled in a manner dependent on the temperature of the first fluid medium, that is to say for example of the coolant.

The cooling radiator arrangement according to the disclosure comprises an inlet and an outlet, a high-temperature cooling radiator arranged downstream of the inlet, a low-temperature cooling radiator arranged downstream of the high-temperature cooling radiator, and an outlet arranged downstream of the low-temperature cooling radiator. Furthermore, the high-temperature cooling radiator comprises an outlet, and the low-temperature cooling radiator comprises an inlet. The outlet of the high-temperature cooling radiator is connected in terms of flow to the inlet of the low-temperature cooling radiator via a flow channel. Here, a control valve according to the disclosure is arranged in the flow channel.

Thus, in other words, in the cooling radiator arrangement according to the disclosure, the outlet of the high-temperature cooling radiator is connected directly to the inlet of the low-temperature cooling radiator. The low-temperature cooling circuit is thus also connected to the high-temperature cooling circuit, and a common coolant pump, for example water pump, can be used for the cooling circuit. Costs, weight, and stowage space are saved in this way.

In one variant, the low-temperature cooling radiator is integrated into the high-temperature cooling radiator, for example in the form of a low-temperature cooling radiator element. In this way, a compact arrangement is realized.

Via the control valve according to the disclosure, the coolant flow in the low-temperature coolant circuit can be automatically controlled, in particular in a manner dependent on the charge pressure, on the temperature of the coolant and on the pressure of the coolant. Typically, more intense cooling of the charge air is desired in the case of higher engine loads and operating states with high engine speeds. This is executed via the control of the valve in a manner dependent on the charge pressure. Via the simultaneous control of the valve in a manner dependent on the temperature of the coolant via the thermostat, the throughflow rate to the low-temperature cooling radiator is automatically controlled in a manner dependent on the coolant temperature. Altogether, therefore, no additional coolant pump is desired for the low-temperature coolant circuit. At the same time, simple and robust control of the low-temperature circuit for the charge-air cooling is provided via the control valve. Furthermore, the complexity of the cooling system, and thus also the susceptibility thereof to failure, is reduced.

The arrangement according to the disclosure of an internal combustion engine with a charge-air cooler in an intake tract, which charge-air cooler is connected to a coolant circuit, wherein the coolant circuit comprises a high-temperature coolant circuit and a low-temperature coolant circuit, relates to an internal combustion engine which is connected to the high-temperature coolant circuit. The intake tract is connected to the low-temperature coolant circuit. The arrangement according to the disclosure comprises a cooling radiator arrangement, wherein the high-temperature coolant circuit is connected to the inlet of the cooling radiator arrangement, and the low-temperature medium circuit is connected to the outlet of the cooling radiator arrangement. The arrangement according to the disclosure has the features and advantages already mentioned above.

The method according to the disclosure for operating an above-described arrangement according to the disclosure comprises the following steps including an internal combustion engine is operated, wherein the control valve is closed, and the temperature of the coolant is detected via the thermostat. The closure is at least partially opened via the pressure of the intake air if a certain threshold value of the pressure of the intake air is overshot. In addition or alternatively, the closure is at least partially opened by the pressure of the coolant if a certain threshold value of the pressure of the coolant is overshot. In addition or alternatively, the opening characteristic curve of the closure is varied via the action of the thermostat if a particular threshold value of the temperature of the coolant is overshot. The method according to the disclosure has the advantages already mentioned above. It permits in particular flexible control of the coolant circuit in a manner adapted to a situation.

The motor vehicle according to the disclosure comprises an above-described arrangement according to the disclosure of an internal combustion engine having a charge-air cooler in an intake tract, which charge-air cooler is connected to a coolant circuit. The motor vehicle according to the disclosure may be a passenger motor vehicle, a heavy goods vehicle, a bus, a minibus or a motorcycle. The motor vehicle according to the disclosure has the features and advantages already mentioned above.

It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.

