Coolant circuit

Abstract

A coolant circuit for an internal combustion engine includes: a coolant pump; at least one coolant line; a radiator; and a coolant cavity delimited in the internal combustion engine. The coolant pump, the coolant line, the radiator and the coolant cavity are filled with a coolant. One or more sensors, configured to monitor the coolant concentration, are fixedly and permanently arranged in and/or on the coolant circuit.

Claims

1. A coolant circuit (2) for an internal combustion engine (1), comprising: a coolant pump (3); at least one coolant line (4); a radiator (7); a coolant cavity (13) delimited in the internal combustion engine (1); an electronic control device (9); and an ambient temperature sensor that measures an outside ambient temperature, the ambient temperature sensor being connected to the electronic control device (9), wherein the coolant pump (3), the coolant line (4), the radiator (7) and the coolant cavity (13) are filled with a coolant (5), one or more sensors (8), configured to monitor the coolant concentration, are fixedly and permanently arranged in or on the coolant circuit (2), at least one of the one or more sensors transmits measuring results thereof to the electronic control device (9), the electronic control device (9) ascertains a temperature below which the coolant (5) would freeze, with reference to the measuring results of at least one of the one or more sensors (8), and compares said temperature below which the coolant (5) would freeze with a measuring result of the ambient temperature sensor (14), and if the comparison between said temperature below which the coolant (5) would freeze and the measuring result of the ambient temperature sensor (14) indicates that the measuring result of the ambient temperature sensor (14) is below said temperature below which the coolant (5) would freeze, the electronic control device (9) electronically prevents the internal combustion engine from starting.

2. The coolant circuit (2) as claimed in claim 1, wherein at least one of the one or more sensors (8) is an ultrasonic sensor.

3. The coolant circuit (2) as claimed in claim 1, wherein the coolant circuit (2) additionally has an expansion vessel (6).

4. The coolant circuit (2) as claimed in claim 3, wherein at least one of the one or more sensors (8) is arranged in or on the expansion vessel (6).

5. The coolant circuit (2) as claimed in claim 1, wherein at least one of the one or more sensors (8) is arranged in or on the coolant cavity (13).

6. The coolant circuit (2) as claimed in claim 1, wherein at least one of the one or more sensors (8) is arranged in or on the coolant pump (3).

7. The coolant circuit (2) as claimed in claim 1, wherein at least one of the one or more sensors (8) is arranged in or on the coolant line (4).

8. The coolant circuit (2) as claimed in claim 1, wherein at least one of the one or more sensors (8) is arranged in or on the radiator (7).

9. The coolant circuit (2) as claimed in claim 1, wherein the electronic control device (9) generates an electronic warning signal if the comparison between said temperature below which the coolant (5) would freeze and the measuring result of the ambient temperature sensor (14) indicates that the measuring result of the ambient temperature sensor (14) is below said temperature below which the coolant (5) would.

10. The coolant circuit (2) as claimed in claim 9, wherein the monitoring of the coolant concentration and the ascertaining of said temperature below which the coolant (5) would freeze and the comparison with the measuring result of the ambient temperature sensor (14) take place even after the internal combustion engine comes to a standstill.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Exemplary embodiments of the invention are explained below with reference to the drawings.

(2) In the drawings:

(3) FIG. 1 shows an internal combustion engine with four cylinders; and

(4) FIG. 2 shows a concentration sensor.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

(5) Elements of identical construction and/or function are provided with the same reference signs throughout the figures.

(6) FIG. 1 shows an internal combustion engine 1 with four cylinders 16 and an exhaust manifold 15 arranged on the internal combustion engine 1. In order to prevent overheating of the internal combustion engine 1 during the operation of the internal combustion engine 1, a coolant circuit 2 is formed on the internal combustion engine 1. The coolant circuit 2 for the internal combustion engine comprises a coolant pump 3, at least one coolant line 4, a radiator 7 and cooling cavities 13 in the internal combustion engine 1. By use of the cooling cavities 13 in the internal combustion engine 1, coolant 5 can absorb the heat from the hot internal combustion engine 1 and transport the heat away. For this purpose, the hot coolant 5 is transported by the coolant pump 3 through the coolant line 4 toward the radiator 7 where the coolant 5 is generally cooled by cold flowing air and is then supplied again to the internal combustion engine 1. The coolant 5 of an internal combustion engine 1 in motor vehicles is generally composed of water, to which a number of corrosion-reducing substances are added. This water has the property of freezing at temperatures below 0° C., which may result in serious damage to the internal combustion engine 1 or to the coolant circuit 2. Substances which reduce the freezing point of the solution to far below 0° C. are therefore generally added to the aqueous coolant 5. However, over the course of a lifetime of a vehicle, the concentration of the substances that reduce the freezing point of the coolant 5 may become too low, and therefore freezing of the internal combustion engine 1 or of the coolant circuit 2 is possible. In order to prevent this, a sensor 8 for monitoring the coolant concentration is fixedly and permanently arranged in the coolant circuit 2. The sensor 8 for monitoring the coolant concentration can be, for example, an ultrasonic sensor. Furthermore, an expansion vessel 6 can be arranged in the coolant circuit 2. The expansion vessel 6 can compensate for the thermal expansion of the coolant 5 in the coolant circuit 2. The sensor 8 for monitoring the coolant concentration can be arranged, for example, in or on the coolant cavity 13 of the internal combustion engine 1. In combination therewith or as an independent solution, the sensor 8 for monitoring the coolant concentration can be arranged on or in the coolant pump 3. Furthermore, the sensor 8 for monitoring the coolant concentration can be arranged in or on the coolant line 4 and/or in or on the radiator 7. The sensor 8 for monitoring the coolant concentration transmits the detected concentration of the coolant solution 5 to an electronic control device 9. The electronic control device 9 is configured to use information regarding the coolant concentration to determine the temperature below which the coolant agent 5 would freeze. This temperature can be compared with an outside temperature transmitted to the electronic control device 9 by an ambient temperature sensor 14. As soon as the electronic control unit identifies that the outside temperature is dropping below the freezing temperature of the coolant 5, the electronic control device can generate a warning signal and/or ensure electronically that the supercooled and/or frozen internal combustion engine is not started.

(7) FIG. 2 shows a concentration sensor 8 which is designed as an ultrasonic sensor. The sensor element 17 is excited into vibrations by a frequency generator 10, which can be integrated in the electronic control device 9, for example, as shown in FIG. 1. However, the sensor element 17 can also be excited into vibrations by an electric circuit 10, wherein the electric circuit 10 is part of the concentration sensor 8 itself, as shown in FIG. 2. These vibrations have frequencies within the ultrasonic range, and therefore an ultrasonic wave 11 is emitted and runs through the coolant 5 to a reflector 12. The ultrasonic wave 11 is reflected at the reflector 12 and thrown back to the sensor element 17. The sensor element 17 then acts as a receiver for the ultrasonic wave 11, wherein the propagating time of the ultrasonic wave 11 from the sensor element 17 via the reflector 12 back to the sensor element 17 is characteristic of the concentration of additives reducing the freezing point in the coolant. The sensor 8 shown here for monitoring the coolant concentration can therefore output a corresponding signal regarding the concentration of the coolant to the electronic control device 9, and therefore the electronic control device 9 can then calculate the temperature from which the coolant 5 would freeze. The coolant circuit 2 presented here for an internal combustion engine 1 with at least one sensor 8 for monitoring the coolant concentration can contribute to avoiding expensive damage to the internal combustion engine 1 and therefore to protecting resources.

(8) 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 be 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.