The present invention relates to a liquid-cooled internal combustion engine with a control of the cooling medium temperature of its cooling medium circulatory system by a thermostatically operating mixing valve, which includes a mixing chamber in open communication with the suction connection of a circulating pump interconnected into the cooling medium circulation and a return chamber connected by way of a radiator return line with the cooling medium outlet of a radiator and adapted to be closed off with respect to the mixing chamber by a return control valve, as well as a by-pass channel connected with the cooling medium outlet of the internal combustion engine, and adapted to be closed off with respect to the mixing chamber by a by-pass control valve, and whose cooling medium oulet is connected with the cooling medium inlet of the radiator by way of a radiator inlet line, and in which the return chamber is connected by way of a venting connection with an auxiliary-chamber fed with cooling medium by the circulating pump by way of the radiator inlet line for the formation of a liquid seal and in which the auxiliary chamber, in its turn, has a venting connection to a geodetic high-point of the cooling medium circulation serving the air separation.
An internal combustion engine of this type represents an internal, non-public development in the facilities of the assignee of the present application. In this internal combustion engine, the two control valves are actuated by an expansion element inserted into the mixing chamber, which responds to the temperature of the cooling medium that establishes itself in the mixing chamber. With a cold engine, the return control valve is closed, whereas, in contradistinction thereto, the by-pass control valve is opened. During the filling of the cooling system, the auxiliary chamber is emptied so that the return chamber together with the radiator return line connected thereto are provided with a filling ventilation by way of the auxiliary chamber. During the operation of the internal combustion engine, the liquid seal of the auxiliary chamber prevents in those operating phases, in which the return control valve is opened, the sucking-in of air by the circulating pump by way of the filling ventilation system of the return chamber.
The present invention is concerned with the task to keep as small as possible the structural expenditure for the filling ventilation system of the return chamber in connection with the aforedescribed internal combustion engine representing the internal, non-public development in the facilities of the assignee of the present application.
The underlying problems are solved in an advantageous manner according to the present invention in that the auxiliary chamber is located in series between two vent lines, of which one is connected to the return chamber and the other is connected to the radiator inlet line.
In the internal combustion engine according to the present invention, the radiator inlet line assumes essentially the removal of the vent particles out of the auxiliary chamber during the filling of the cooling system so that the expenditures in lines for this purpose are kept as small as possible.
In internal combustion engines with a thermostatically operating mixing valve, it is customary that the mixing valve includes two communicating valve connections, of which one valve connection connects the by-pass channel with the cooling medium outlet of the internal combustion engine and the other valve connection connects the radiator inlet line with the cooling medium outlet of the internal combustion engine.
In application of the present invention to such an internal combustion engine, the arrangement may be made in an advantageous manner such that the mixing valve includes a housing channel which connects a vent connection of the return chamber with a vent connection in the valve connection for the radiator inlet line.
In this manner, optimally short line paths for the filling ventilating system of the return chamber are obtained.
Accordingly, it is an object of the present invention to provide a liquid-cooled internal combustion engine which avoids by simple means the aforementioned shortcomings and drawbacks encountered in the prior art.
Another object of the present invention resides in a liquid-cooled internal combustion engine in which the length of lines is kept as short as possible, especially for the venting system of the mixing chamber.
A further object of the present invention resides in a liquid-cooled internal combustion engine which is characterized by extremely efficient operation, yet is relatively simple in construction and utilizes relatively simple, few parts.
Still a further object of the present invention resides in a liquid-cooled internal combustion engine in which a liquid seal is used to prevent the drawing-in of air by the circulating pump during the operation of the engine notwithstanding the presence of a fill-in venting system.
These and further objects, features and advantages of the present invention will become more apparent from the following description when taken in connection with the accompanying drawings, which show, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:
FIG. 1 is a schematic view of the cooling medium circulatory system of the internal combustion engine according to the present invention;
FIG. 2 is a partial axial cross-sectional view through the mixing valve of FIG. 1, on an enlarged scale, and illustrating certain details thereof; and
FIG. 3 is a plan view on the annular seal of FIG. 2, illustrated as an individual part.
Referring now to the drawings wherein like reference numerals are used throughout the various views to designate like parts, the cooling spaces 1 and 2 of the internal combustion engine generally designated by reference numeral 3, which are traversed sequentially by the cooling medium, are interconnected in a cooling medium circulatory system generally designated by reference numeral 4 which is subdivided by a thermostatically operating mixing valve generally designated by reference numeral 5, into a by-pass circulation generally designated by reference numeral 6 and into a radiator circulation generally designated by reference numeral 7. The cooling medium inlet and the cooling medium outlet of the internal combustion engine 3 are designated by reference numerals 8 and 9.
A circulating pump 11 which is connected with its pressure connection 10 to the cooling medium inlet 8 and which is driven by the internal combustion engine 3, is in open communication on its suction side by way of a suction line 12 with a mixing chamber 13 of the mixing valve 5. The mixing valve 5 is provided with two communicating valve connections 14 and 15 for the cooling medium outlet 9 of the internal combustion engine 3 and for a cooling medium inlet line 18 which leads to an upper water tank or box 16 of a radiator 17. A by-pass channel 19 of the mixing valve 5, which is connected with the cooling medium outlet 9 by way of the valve connection 14, is connected with the mixing chamber 13 by way of a by-pass control valve generally designated by reference numeral 20. A return chamber 23 of the mixing valve 5 which is connected with the lower water tank or box 22 of the radiator 17 by way of a radiator return line 21, is connected with the mixing chamber 13 by way of a return control valve generally designated by reference numeral 24. The control valves 20 and 24 are actuated in a conventional manner by a cylinder 25 of an expansion element, which is arranged in the mixing chamber 13 and is filled with a temperature-sensitive expansion material, and whose piston rod 26 is locally fixed in the mixing valve 5.
A venting connection indicated at 27 is provided in the housing of the mixing valve 5 for the return chamber 23, which is connected with a venting opening 32 in the valve connection 15 for the radiator inlet line 18 by way of a housing channel 29 which operates as auxiliary chamber with liquid seal and also extends inside of the housing of the mixing valve 5.
During the filling of the cooling system by way of the opened filler connection 33 of the upper water box 16, the return control valve 24 is closed. Air enclosed or entrapped in the line system 21, 23 escapes into the atmosphere by way of parts 27-29-32-18-33.
During the operation of the internal combustion engine, water droplets or water pearls continuously enter the housing channel 29 from the valve connection 15 of the radiator inlet line 18 by way of the vent opening 32, where they act in the manner of a liquid seal and prevent -- with a slightly lowered liquid level in the radiator 17 and therewith in the cooling inlet line 18 -- the drawing-in of air out of the upper water box 16 by the circulating pump 11 which otherwise would lead to a breaking-away or separation of the cooling medium stream as a result of an air bubble.
The mixing valve 5 consists of a valve housing 34 (FIG. 2) having a separating surface 35, on which is placed a valve housing cover 36 having a corresponding separating surface 37 whereby the edge 38 of a valve seating disk generally designated by reference numeral 39 is simultaneously clamped-in. The mutually coaxially disposed valve disks or plates 40 (FIG. 1) and 41 (FIG. 2) of the by-pass control valve 20 and of the return control valve 24 are retained at the valve seating disk 39 in a conventional manner. The housing channel 29 includes a channel section 43 extending parallel to the common axis 42 (FIG. 2) of the valve disks 40 and 41, which extends through the separating surfaces 35 and 37. The edge 38 is surrounded by an annular seal 44 which at the location of the housing channel 29 includes a tongue-like tab or lug 45 with a cylindrical through-flow opening 46 (FIG. 3) which is aligned with the channel section 43 in the installed position. For securing this installed position, the annular seal 44 is provided at its outer circumference with three fixing nose portions 47.
While I have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and I therefore do not wish to be limited to the details shown and described herein but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.