Expansion tank for a vehicle's cooling system and vehicle with such an expansion tank

Abstract

Expansion tank (1) for a cooling system of a liquid-cooled internal combustion engine of a vehicle with • a horizontal partition (4) dividing the volume of the expansion tank (1) into a lower sub-volume (5) and an upper sub-volume (6), • a suction opening (10) located in the lower partial volume (5) and connected to the cooling system, • a minimum volume of coolant (12) located in the expansion tank (1), • a passage opening (8) connecting the two partial volumes (5, 6) for the coolant (12), wherein • the passage opening (8) in the partition wall (4) is arranged above the suction opening (10), wherein the partition wall (4) is connected on the outside around the perimeter and sealingly to a wall surface (7) of the expansion tank (1), • the minimum volume of the cooling liquid (12) is arranged in the lower partial volume (5) and a liquid level (13) of the minimum volume in the lower partial volume (5) is located below the partition (4) and above the extraction opening (10) regardless of any inclination to a horizontal plane (14), • the passage opening (8) and the partition (4) are designed and arranged relative to the suction opening (10) such that the suction opening (10) lies below the liquid level (13) up to a maximum angle of inclination (15) of the liquid level (13) relative to the horizontal plane (14), wherein the liquid level (13) at the maximum angle of inclination (15) extends from an opening edge section (18) of the passage opening (8) in the partition (4) in the direction of an edge section (19) of a bottom wall (9) of the compensation tank (1) that limits the suction opening (10), characterized in that the dimensions of the passage opening (8) and / or the suction opening (10) and / or a distance (17) of the partition (4) from the suction opening (10) are selected such that the maximum angle of inclination (15) of the liquid level (13) relative to the horizontal plane (14), in which the suction opening (10) is still below the liquid level (13), is between 40° and 60° and that the lower partial volume (5) of the expansion tank (1) is smaller than the upper partial volume (6), the upper partial volume (6) forming an air reservoir for the cooling system.

Description

[0001] The invention relates to an expansion tank for a cooling system of a liquid-cooled internal combustion engine of a vehicle with • a horizontal partition dividing the volume of the expansion tank into a lower sub-volume and an upper sub-volume, • an extraction opening located in the lower part of the volume and connected to the cooling system, • a minimum volume of coolant located in the expansion tank, a flow opening connecting the two partial volumes for the coolant, wherein • the passage opening in the partition wall is arranged above the suction opening, wherein the partition wall is connected on the outside around the perimeter and in a sealing manner to a wall surface of the expansion tank (1), • the minimum volume of the cooling liquid is located in the lower sub-volume and a liquid level of the minimum volume in the lower sub-volume is located below the partition and above the extraction opening, regardless of any inclination to a horizontal plane, • the passage opening and the partition are designed and arranged relative to the suction opening in such a way that the suction opening is located below the liquid level up to a maximum angle of inclination of the liquid level relative to the horizontal plane, wherein the liquid level at the maximum angle of inclination extends from an opening edge section of the passage opening in the partition towards an edge section of a bottom wall of the expansion tank that limits the suction opening.

[0002] Furthermore, the invention relates to a vehicle with such an expansion tank.

[0003] An expansion tank of the type mentioned is already known from DE 202 17 307 U1. This expansion tank has a horizontally extending partition wall which is located inside the expansion tank below a minimum volume of coolant level. The partition wall is positioned on the bottom of the expansion tank via a central base such that a slit-shaped opening for the coolant is formed between a circumferential edge of the partition wall and an inner wall of the tank. The partition wall separates the coolant in the expansion tank into a partially foamed area above the partition wall, where air is also separated from the coolant, and a calmer area below the partition wall.The suction opening is located at the bottom of the expansion tank, in the calmed area below the partition wall and is adjacent to the central base.

[0004] Further expansion tanks for coolant with one or more partitions for achieving air separation from the coolant are disclosed in EP 1 878 891 A1 and EP 3 032 064 A1.

[0005] The subject of DE 603 ​​16 566 T2 is a hydraulic fluid reservoir for a brake system with an overflow protection partition arranged on the reservoir ceiling. The partition is intended to limit the loss of hydraulic fluid through the supply opening.

[0006] In the expansion tank of a liquid-cooled internal combustion engine's cooling system, in addition to the minimum volume of coolant (which prevents air from being drawn into the system), there is also a so-called air buffer. The air buffer is the required amount of air in the expansion tank to compensate for the expansion of the coolant in the cooling system due to temperature changes. Accordingly, large cooling systems require a larger air buffer in the expansion tank. If the minimum volume of coolant in the expansion tank is too low, especially when cornering, accelerating or braking, or driving on an incline, the coolant within the tank can be displaced to such an extent that air is drawn into the cooling system through the vent.Air loss can be prevented by increasing the minimum volume of the coolant. However, this simultaneously reduces the air space in the expansion tank, which, depending on the size of the cooling system, may then no longer be sufficient to compensate for the expansion of the coolant due to a temperature increase.

[0007] To accommodate a larger air volume and a larger minimum volume of coolant, the expansion tank's capacity would need to be increased accordingly. However, due to the existing space limitations in the vehicle's engine compartment, this solution is not feasible.

[0008] Since increasing the size of the expansion tank is not practical, the pressure in the cooling system would have to be increased, for example, by modifying the valve. However, in the case of a pressure increase, it is necessary to adapt all components of the cooling system, as well as the filling process during production, to the new pressure level.

[0009] Another option is to divide the single large cooling circuit into several smaller cooling circuits. However, since each small cooling circuit then requires its own expansion tank, problems also arise regarding space limitations in the vehicle's engine compartment.

[0010] Another option is to reduce the cooling circuit volume by using air-cooled instead of liquid-cooled components. However, this also presents problems with limited installation space, as air-cooled components require more space for air circulation.

[0011] DE 10 2013 001 681 A1 further describes an expansion tank for the cooling system of an internal combustion engine. The tank consists of a lower and an upper domed shell, manufactured using plastic injection molding and welded along their edges. The tank has an upper and a lower connection port as well as a closable filling opening. The inner walls of the tank shells run vertically to the plane that encloses the edges of the shells and, at a certain distance from the tank circumference, form at least one inner chamber, which is connected via openings to at least one outer chamber created by this connection.

[0012] From DE 10 2013 018 781 B3, an expansion tank for the coolant of an engine cooling system is further disclosed, in which at least one baffle with a passage is arranged in the expansion volume, dividing the volume into several sections. A sealing device, in particular with flaps movable between a sealing position and an opening position, closes the passage depending on the lateral acceleration.

[0013] EP 3 012 429 A1 describes an expansion vessel for the cooling system of a motor vehicle, in which an inlet basin and a settling basin are connected by a flow channel. The outlet opening is positioned so that even at a slight incline of less than 40° it is no longer below the liquid level.

[0014] From DE 28 48 846 A1, a combination of an expansion vessel and a degassing vessel is known, separated by a wall. This wall has one or more bores in its edge region, enabling complete drainage of the liquid by gravity. The maximum angle of inclination of the liquid level, at which the suction opening is still below the liquid level, is greater than 60°.

[0015] DE 10 2011 084 263 A1 also describes an expansion tank for the cooling system of a liquid-cooled internal combustion engine of a vehicle. This tank is divided into a lower and an upper compartment by a horizontal partition. The lower compartment contains a suction opening connected to the cooling system. The tank contains a specific minimum quantity of coolant, which is located in the lower compartment. A through-hole in the partition connects the two compartments and is located above the suction opening. The partition is completely and tightly connected to the outer surface of the tank. The level of the minimum quantity of coolant in the lower compartment always remains below the partition and above the suction opening, regardless of any inclination.The arrangement and design of the through-hole and the partition ensure that the suction opening remains below the liquid level even at the maximum angle of inclination. At maximum inclination, the liquid level extends from an edge section of the through-hole in the partition towards the edge section of the bottom wall that defines the suction opening.

[0016] Against this background, the invention aims to provide an improved expansion tank for the cooling system of a vehicle's internal combustion engine, which requires only a very small minimum volume of coolant to prevent air from being drawn in through the suction opening. This is achieved by allowing the coolant to flow from the lower to the upper part of the tank as the fluid level increases, as is to be expected during vehicle operation due to dynamic forces. Simultaneously, a reduction in the minimum coolant volume should ensure an increased air reserve, so that the expansion tank is also suitable for larger cooling circuits with the same installation space requirements.

[0017] This problem is solved with a compensation tank according to the features of claim 1. The dependent claims relate to particularly advantageous further developments of the invention.

[0018] According to the invention, an expansion tank for a cooling system of a liquid-cooled internal combustion engine of a vehicle is provided, in which • the passage opening in the partition wall is arranged above the suction opening, wherein the partition wall is connected to a wall surface of the expansion tank on the outside, all around and sealingly, • the minimum volume of the cooling liquid is located in the lower sub-volume and a liquid level of the minimum volume in the lower sub-volume is located below the partition and above the extraction opening, regardless of any inclination to a horizontal plane, • the passage opening and the partition are designed and arranged relative to the suction opening in such a way that the suction opening is located below the liquid level up to a maximum angle of inclination of the liquid level relative to the horizontal plane, wherein the liquid level at the maximum angle of inclination extends from an opening edge section of the passage opening in the partition towards an edge section of the wall surface of the expansion tank that limits the suction opening.

[0019] According to the invention, the dimensions of the through-hole and / or the suction opening and / or the distance of the partition from the suction opening are selected such that the maximum angle of inclination of the liquid level relative to the horizontal plane in which the suction opening is still below the liquid level is between 40° and 60°, preferably between 45° and 55°. To prevent air from being drawn out even at larger angles of inclination, the distance between the partition and the suction opening would have to be increased, assuming the size of the through-hole remains the same. With the same size of the expansion tank, this would result in an increase in the lower volume and a decrease in the upper volume. Consequently, a smaller air charge and a larger minimum volume of coolant would be required.Alternatively, if the distance between the partition and the extraction opening remains constant, the size of the through-hole would have to be reduced accordingly. This, in turn, would result in adverse changes, including to the cooling system filling process during vehicle production.

[0020] Furthermore, according to the invention, the lower volume of the expansion tank is smaller than the upper volume, with the upper volume forming an air reservoir for the cooling system. This ensures that the air reservoir is enlarged when the minimum volume of the coolant is reduced. As a result, the expansion tank can be used for larger cooling circuits without changing its volume, i.e., with the same installation space requirements.

[0021] The design according to the invention ensures that, under all driving conditions of the vehicle, particularly when cornering, braking, accelerating, or driving on an incline, the suction opening remains below the liquid level in the lower volume below the horizontal partition. This prevents air from being drawn in through the suction opening and introduced into the cooling system of the internal combustion engine, which is connected to the expansion tank via a suction port and a line. During dynamic driving or the aforementioned driving conditions, the minimum volume of coolant is moved or displaced within the lower volume defined by the partition.The horizontal partition prevents the coolant from settling in the upper section, at least up to a maximum angle of inclination. This reduces the minimum coolant volume required to prevent air from being drawn in through the vent. The vent ensures that the coolant, which expands when the temperature rises, can flow into the upper section and, when it cools, back from the upper section into the lower section. The reduced minimum coolant volume simultaneously increases the air volume in the expansion tank.The maximum angle of inclination at which it is ensured that the suction opening lies below the liquid level depends directly on the dimensions of the passage opening and / or the dimensions of the suction opening and / or on the distance of the partition wall accommodating the passage opening from the suction opening located in a base surface of the expansion tank.

[0022] Furthermore, the design stipulates that the through-hole and the partition are configured and positioned relative to the suction opening in such a way that the suction opening remains below the liquid level, regardless of the liquid level's inclination relative to the horizontal plane. This effectively prevents air from being drawn in through the suction opening of the expansion tank, not only during cornering, braking, acceleration, and road camber, but also during combinations of these conditions. For example, this would prevent air from being drawn in through the suction opening of the expansion tank, even during cornering.

[0023] A further advantageous embodiment of the invention is achieved by arranging a sensor for detecting the coolant level in the expansion tank such that at least one end section of the sensor is located in the lower part of the volume and lies below the coolant level regardless of the inclination of the coolant level in the minimum volume relative to the horizontal plane. This ensures that the sensor always remains below the coolant level, even during dynamic vehicle operation, thus preventing unwanted indications or warnings of a coolant shortage from the sensor.

[0024] The production of the expansion tank is further simplified by arranging the horizontal partition in a dividing plane between the upper and lower shells of the tank. This allows the components, which are separate parts, to be easily joined and sealed in a single step. Alternatively, the partition can first be joined to only one shell, and this semi-finished product then subsequently joined to the other shell.

[0025] Another advantageous embodiment of the invention is characterized in that a surface of the partition, which delimits the lower partial volume and / or the upper partial volume, has a flow-guiding structure oriented towards the through-opening. This ensures improved air separation, as the air located in the lower partial volume is guided by the flow-guiding structure towards the through-opening and through it into the upper partial volume. Furthermore, coolant located in the upper partial volume flows in a controlled manner towards the through-opening and through it back into the lower partial volume of the expansion tank.

[0026] It proves particularly advantageous that the structuring is formed by raised areas and / or recesses in the partition. Recesses designed as grooves and / or raised areas designed as ribs or ribbing provide a simple and effective flow path for the air and coolant.

[0027] An alternative embodiment of the invention, in contrast to the structuring in the partition wall, provides that a surface of the horizontal partition wall, which defines the lower partial volume and / or a surface which defines the upper partial volume, each has an inclination directed towards the passage opening. This also allows the air in the lower partial volume and the coolant in the lower air volume to be easily directed to the passage opening and flow from the respective partial volume into the other partial volume.

[0028] According to the invention, a vehicle is also provided with a previously described expansion tank for a cooling system of a liquid-cooled internal combustion engine.

[0029] The invention allows for numerous embodiments. To further illustrate its basic principle, one of these is shown in the drawing and described below. This shows in Fig. 1 A schematic representation of an expansion tank without coolant in a sectional view; Fig. 2 den in Fig. 1. Expansion tank shown with a minimum volume of coolant and a horizontally extending liquid level; Fig. 3 the expansion tank with a minimum volume of coolant and a liquid level that is inclined; Fig. 4 the expansion tank with a minimum volume of coolant and a liquid level that is inclined; Fig. 5 a schematic representation of an expansion tank with a sensor for detecting the coolant level; Fig. 6 a perspective and partially cutaway view of the expansion tank; Fig. 7 one in Fig. 6. Partition wall of the expansion tank shown in a top view; Fig. 8 the in Fig. 6. Partition wall of the expansion tank shown in a bottom view.

[0030] Based on the Fig. In sections 1 to 8, an expansion tank 1 according to the invention for a cooling system of a liquid-cooled internal combustion engine of a vehicle (not shown) is described below.

[0031] The expansion tank 1, which encloses a reservoir volume, has a lower reservoir shell 2 and an upper reservoir shell 3. The reservoir volume is divided into a lower sub-volume 5 and an upper sub-volume 6 by a horizontally extending partition 4. The partition 4 is connected to a wall surface 7 of the expansion tank 1 on its outer surface in a sealing manner. A flow-connecting opening 8, which has a circular cross-section, is arranged in the partition 4. In the lower sub-volume 5 of the expansion tank 1, a suction opening 10 with a suction port 11 is located in a bottom wall 9 of the expansion tank 1. The expansion tank 1 is connected to the cooling system of the internal combustion engine via a line connected to the suction port 11.

[0032] In the illustrated embodiment, the upper partial volume 6 of the expansion tank 1, which forms an air reservoir for the cooling system, is significantly larger than the lower partial volume 5. The smaller lower partial volume 5 contains a minimum volume of coolant 12. This minimum volume of coolant 12 is dimensioned such that, under a first driving condition of the vehicle, a liquid level 13 of the minimum volume extends parallel to a horizontal plane 14 and below the partition 4. The horizontal plane 14 is defined by a transverse direction (y-direction) and a longitudinal direction (x-direction) of the tank, or by a transverse direction (y-direction) and a longitudinal direction (x-direction) of the vehicle. In the illustrated embodiment, the horizontal partition 4 extends in the horizontal plane 14. In the first driving condition, in which the liquid level 13 of the minimum volume of coolant 12 extends below the level of the expansion tank 14, the lower partial volume 5 contains a minimum volume of coolant 12. Fig. In the position shown in Figure 2, the vehicle is stationary on a substantially level road surface or is moving straight ahead at a constant speed on a level road surface. In a different driving condition, particularly during dynamic driving, for example when cornering, accelerating, or braking, or when the vehicle is on or moving on an inclined road, the minimum volume of coolant 12 in the lower sub-volume 5 of the expansion tank 1 is displaced laterally, so that the fluid level 13 assumes a position inclined relative to the horizontal plane 14. Fig. 3 and Fig. Figure 4 shows such a liquid level 13 of the minimum volume of the coolant 12, which has an inclination relative to the horizontal plane 11, when the vehicle is cornering in opposite directions. In both cases, the liquid level 13 is arranged at a maximum inclination angle 15 but in different directions of inclination relative to the horizontal plane 14.

[0033] To prevent unwanted air extraction through the extraction opening 10 during dynamic vehicle driving, particularly under the aforementioned driving conditions, the passage opening 8 and the partition wall 4 are designed and arranged relative to the extraction opening 10 and the floor wall 9, respectively, such that the extraction opening 10, as shown in Fig. Figure 5 shows that the liquid level 13 is also below the respective liquid level 13, which, as a result of one of the aforementioned driving conditions of the vehicle, has an inclination relative to the horizontal plane 14. The maximum inclination angle 15 of the liquid level, at which the suction opening 10 is still below the inclined liquid level 13, is determined by the dimensions, in particular by a diameter 16 of the passage opening 8 and a distance 17 of the partition wall 4 from the suction opening 10 or the bottom wall 9. At the maximum inclination angle 15 shown, the respective liquid level 13 extends from an opening edge section 18 of the passage opening 8 towards an edge section 19 of the bottom wall 9 of the expansion tank 1 that limits the suction opening 10. Fig. Figure 5 clearly shows that the suction opening 10 is located below the two liquid levels 13 shown by dashed lines and arranged at a maximum angle of inclination 15 of about 45° to the horizontal plane 14, so that the suction of air through the suction opening 10 is effectively prevented.

[0034] Furthermore, in Fig. Figure 5 shows a sensor 20 for detecting the coolant level 12 or a coolant shortage in the expansion tank 1. The sensor 20 extends from a wall in the upper part 3 of the tank, through the opening 8, and into the lower section 5. An end section 21 of the sensor 20 is positioned in a space between the opening 8 and the suction opening 10 in the lower section 5 such that it lies below the respective liquid levels 13, regardless of the inclination of the liquid levels relative to the horizontal plane 14. This ensures that no indication or warning of a coolant shortage occurs during dynamic driving of the vehicle.

[0035] As in Fig.As can be clearly seen in Figures 6 to 8, the passage opening 8 has a circular cross-sectional area. Furthermore, a surface 22 bounding the lower sub-volume 5 and a surface 23 bounding the upper sub-volume 6 of the partition wall 4 each have a flow-guiding structure 24 in the form of ribbing consisting of several protrusions 25, which are oriented towards the passage opening 8. The air in the lower sub-volume 5 and the coolant 12 in the upper sub-volume 6 are guided by these structures 24 towards the passage opening 8 and then pass through the passage opening 8 into the respective other sub-volume 5, 6. Reference symbol list 1 expansion tank 2 Container base 3 Container top 4 Partition wall 5 lower subvolume 6 upper partial volume 7 wall surface 8 Passage opening 9 Floor wall 10 Extraction opening 11 suction ports 12 Coolant 13. Fluid levels 14 Horizontal plane 15 tilt angles 16 diameter 17 distance 18 Opening edge section 19 Marginal section 20 Sensor 21 Final section 22 surface 23 Surface 24 Structuring 25 Survey

Claims

[1] Expansion tank (1) for a cooling system of a liquid-cooled internal combustion engine of a vehicle with • a horizontal partition wall (4) dividing a container volume of the expansion tank (1) into a lower partial volume (5) and an upper partial volume (6), • a suction opening (10) arranged in the lower part of the volume (5) and connected to the cooling system, • a minimum volume of a coolant (12) in the expansion tank (1), • a passage opening (8) for the cooling liquid (12) connecting the two partial volumes (5, 6), wherein • the passage opening (8) in the partition wall (4) is arranged above the suction opening (10), the partition wall (4) being connected on the outside circumferentially and sealingly to a wall surface (7) of the expansion tank (1), • the minimum volume of the cooling liquid (12) is arranged in the lower partial volume (5) and a liquid level (13) of the minimum volume in the lower partial volume (5) is below the partition wall (4) and above the suction opening (10), regardless of an inclination relative to a horizontal plane (14), • the passage opening (8) and the partition wall (4) are designed and arranged relative to the suction opening (10) in such a way that the suction opening (10) lies below the liquid level (13) up to a maximum angle of inclination (15) of the liquid level (13) relative to the horizontal plane (14), wherein the liquid level (13) extends at the maximum angle of inclination (15) from an opening edge section (18) of the passage opening (8) in the partition wall (4) in the direction of an edge section (19) of a bottom wall (9) of the compensation tank (1) delimiting the suction opening (10), characterized by , that the dimensions of the passage opening (8) and / or the suction opening (10) and / or a distance (17) of the partition wall (4) from the suction opening (10) are selected such that the maximum angle of inclination (15) of the liquid level (13) relative to the horizontal plane (14), in which the suction opening (10) is still below the liquid level (13), is between 40° and 60° and that the lower partial volume (5) of the expansion tank (1) is smaller than the upper partial volume (6), the upper partial volume (6) forming an air reservoir for the cooling system. [2] Expansion tank (1) according to claim 1, characterized by that the passage opening (8) and the partition wall (4) are designed and arranged relative to the suction opening (10) in such a way that the suction opening (10) lies below the liquid level (13) regardless of a direction of inclination of the liquid level (13) relative to the horizontal plane (14). [3] Expansion tank (1) according to at least one of the preceding claims, characterized by that a sensor (20) for detecting a fill level of the cooling liquid (12) is arranged in the expansion tank (1) in such a way that at least one end section (21) of the sensor (20) is arranged in the lower partial volume (5) and lies below the liquid level (13) regardless of the inclination of the liquid level (13) of the minimum volume relative to the horizontal plane (14). [4] Expansion tank (1) according to at least one of the preceding claims, characterized by that the partition wall (4) is arranged in a parting plane between a tank upper shell (3) and a tank lower shell (2) of the expansion tank (1). [5] Expansion tank (1) according to at least one of the preceding claims, characterized bythat a surface (22) delimiting the lower partial volume (5) and / or a surface (23) of the partition wall (4) delimiting the upper partial volume (6) has a flow-guiding structure (24) which is oriented in the direction of the passage opening (8). [6] Expansion tank (1) according to at least one of the preceding claims, characterized by that the structuring (24) is formed by elevations (25) and / or depressions in the partition wall (4). [7] Expansion tank (1) according to at least one of the preceding claims, characterized by that a surface (22) delimiting the lower partial volume (5) and / or a surface (23) of the partition wall (4) delimiting the upper partial volume (6) has an inclination directed in the direction of the passage opening (8). [8] Vehicle with an expansion tank (1) for a cooling system of a liquid-cooled internal combustion engine according to at least one of the preceding claims.

Images