Coolant expansion tank with integrated swirl chamber spaced from the tank wall along its entire circumference

Abstract

Coolant expansion tank (10) for arrangement in a coolant circuit (41), comprising: - a container housing (12), - in the container housing (12) a vortex chamber (42) - a supply line (40) for introducing coolant into the container housing (12), and - an outlet opening (58) for draining coolant from the container housing (12), wherein the feed line (40) leads into the vortex chamber (42), wherein the vortex chamber (42) is defined by a wall (44) projecting along a vortex chamber axis (W) from a base wall section (44c) of the container housing (12), which is circumferentially enclosed around the vortex chamber axis (W) and is arranged at a distance from the container housing (12) in every direction orthogonal to the vortex chamber axis (W), characterized in that a flow guide plate (48) is arranged inside the vortex chamber (42), and the flow guide plate (48) extends only around a circumferential section, but not completely enclosed around the vortex chamber axis (W), wherein a gap (49) is formed between the inner surface of the wall of the vortex chamber (42) and a surface of the flow guide plate (48) facing the wall of the vortex chamber (42), the gap (49) has a gap spacing along a flow path of the cooling fluid in the gap (49), and wherein the gap spacing in the circumferential direction around the vortex chamber axis (W) is smaller orincreasing in size to accelerate or decelerate the coolant in the swirl chamber (42).

Description

[0001] The present invention relates to a coolant expansion tank for arrangement in a coolant circuit, in particular in a motor vehicle, comprising: - a container housing, - a vortex chamber in the container housing - a supply line for introducing coolant into the tank housing, and - an outlet opening for discharging cooling liquid from the tank housing, with the supply line opening into the swirl chamber.

[0002] Such a coolant expansion tank, hereinafter referred to simply as "expansion tank," is known from DE 100 50 852 A1. Like the expansion tank of the present invention, this known expansion tank is also suitable and intended for installation in a motor vehicle's coolant circuit, hereinafter referred to simply as the "cooling circuit."

[0003] Such expansion tanks in the cooling circuit typically fulfill two functions: First, they provide a compensating volume to accommodate the increase in volume of the coolant circulating in the cooling circuit caused by temperature increases. Second, expansion tanks ensure degassing of the coolant, usually via so-called swirl chambers, which is advantageous for preventing unwanted cavitation on conveying devices for the coolant in the cooling circuit, such as pump impellers and valves.

[0004] Common cooling circuits with expansion tanks for vehicles with internal combustion engines operate at a flow rate of approximately 5 l / min. Surprisingly, battery-powered electric vehicles require significantly higher coolant flows of 10 or even 12 l / min or more to cool their heating components. As the coolant flow rate increases, its degassing becomes more difficult, which is presumably related to the increasingly shorter residence time of the coolant in the expansion tank for a given capacity of the expansion tank.

[0005] Numerous other expansion tanks are known from the prior art. With some relevance to the present invention, reference is also made to the expansion tank in DE 10 2008 060 088 B4.

[0006] In both known expansion tanks with a swirl chamber integrated into the expansion tank, a portion of the swirl chamber wall, which radially delimits the swirl flow occurring in the swirl chamber, is also part of the tank wall to realize potential savings in material and manufacturing costs. DE 100 50 852 A1 also discloses dividing an area inside the tank housing, but outside the swirl chamber, into several separate chambers. The partition walls separating the chambers have communication openings through which coolant can flow from one chamber into the adjacent chamber beyond the partition wall.

[0007] US 2016 0 208 678 A1 discloses an expansion tank for creating a cyclonic flow direction for incoming coolant. The degassing bottle comprises a body and an air separator with a cylindrical wall. An inlet for the incoming coolant is attached to the upper end of the air separator and arranged tangentially to the cylindrical wall of the air separator, so that a cyclonic effect is created when the coolant enters the air separator. The air separator can be cylindrical or conical in shape. As the coolant, trapped in air, flows tangentially into the air separator, it follows the cylindrical or conical shape of the air separator. Centrifugal force presses the incoming coolant against the inner wall of the air separator, while the air separates from the coolant. The cyclically flowing coolant circulates downwards towards the tank, while the air remains on top of the coolant.

[0008] Further expansion tanks are known from DE 100 50 852 A1, DE 696 17 066 T2, US 2 556 319 A and US 2019 0 091 607 A1.

[0009] It is an object of the present invention to improve the expansion tank mentioned at the outset in such a way that it effectively enables thermally induced expansion of the coolant and its degassing even at higher volume flows of coolant of more than 10 or even more than 12 l / min without increasing the installation space.

[0010] The present invention solves this problem with a coolant expansion tank according to claim 1.

[0011] In principle, the vortex chamber into which the cooling liquid is introduced can have almost any shape. To achieve the least turbulent flow after the cooling liquid is introduced into the vortex chamber, the wall of the vortex chamber, which encircles the vortex chamber axis in a closed manner, has a kink-free, concavely curved inner surface. The inner surface of the wall is preferably free of flow obstructions, such as webs protruding from the inner surface or impact surfaces protruding from the wall towards the vortex chamber axis. The vortex chamber can have a spherical or spherical cap-shaped inner surface. The vortex chamber preferably has a circular-cylindrical or elliptical-cylindrical inner surface.It is also not excluded that different inner surface shapes are combined in different areas of the wall of the vortex chamber, for example when a cylindrical inner wall surface in the area of ​​a cylinder end face is adjoined by a wall section with a dome-shaped inner surface.

[0012] The swirl chamber of the expansion tank of the present invention can also have a wall section formed jointly with the tank housing wall, for example, at the base wall section to form an inner wall surface that delimits the swirl chamber and is oriented transversely to the swirl chamber axis. If there is only one swirl chamber axis, the swirl chamber can have a cylindrical, conical, or generally chamber shape that tapers and / or widens in sections along the swirl chamber axis. The inner surface of the wall of the swirl chamber has, in sectional planes orthogonal to the swirl chamber axis, closed cutting lines encircling the swirl chamber axis. These are preferably circles, although elliptical or oval cutting lines should not be excluded.

[0013] By introducing the coolant into the swirl chamber, it can flow along the inner wall surface of the swirl chamber, as already known from the prior art, usually in a vortex, thereby degassing. By designing the swirl chamber wall at a distance from the tank housing, i.e., the tank wall, orthogonal to the swirl chamber axis, a long flow path for the coolant can be created within the expansion tank but outside the swirl chamber. This can increase the residence time of the coolant in the expansion tank, thus improving the degassing results.

[0014] Due to the aforementioned design of the swirl chamber at a distance from the tank housing, the swirl chamber can be completely enclosed in the tank housing on its outer side, allowing the coolant to flow around it circumferentially. The ability of the coolant to flow around the swirl chamber on its outer side after leaving the swirl chamber, but still inside the tank housing, thus generating an annular flow outside the swirl chamber in addition to the swirl flow in the swirl chamber, allows the residence time of the coolant in the expansion tank to be further increased, thus allowing the coolant to be degassed more effectively over a longer period despite the larger volume flow.

[0015] In principle, the base wall section, from which the wall defining the vortex chamber protrudes, can be any wall section of the container housing, for example, a side wall of the container or a section of the container ceiling or the container floor. Preferably, the base wall section is a section of the container floor or of the container ceiling opposite the container floor, so that the vortex chamber axis, in the fully assembled, ready-to-use state, runs essentially parallel to the direction of gravity or at least in a cone with a half-opening angle of 10° around a cone axis parallel to the direction of gravity, which intersects the vortex chamber axis.A cooling fluid flow introduced into the vortex chamber can then advantageously circulate around the vortex chamber axis in a vortex flow along a side wall of the vortex chamber, with gravity having essentially the same effect on the flowing cooling fluid at every circumferential location along the vortex flow. If the vortex chamber axis is tilted too sharply relative to the direction of gravity, undesirable flow separation can occur at the then existing upper apex of the vortex flow around the vortex chamber axis.

[0016] To ensure that the cooling fluid introduced into the swirl chamber can also reach the area outside the swirl chamber but still within the tank housing, the wall of the swirl chamber preferably has at least one through-opening that completely penetrates the wall in the thickness direction. The through-opening is preferably formed at a location that is geodetically as low as possible when the expansion tank is in the ready-to-operate state, so that the cooling fluid can be introduced into the swirl chamber at a location that is geodetically as high as possible, thus traveling the longest possible path within the swirl chamber before reaching the through-opening. The through-opening is preferably arranged such that a section of it is delimited by the tank bottom.

[0017] Deviating from the above, the outlet of the supply line into the vortex chamber can be located at the same height as at least one through-hole. This is particularly possible with high volume flows of 12 l / min or more, for example, more than 20 l / min or more than 30 l / min. Therefore, the outlet of the supply line can also be located at a geodetically low point, in particular at the geodetically lowest point, of the vortex chamber. Due to the high volume flow, the introduced cooling fluid can then rise from the geodetically low outlet, thus extending its flow path and thus its residence time.

[0018] In principle, a single through-opening in the wall of the swirl chamber can be sufficient. To ensure that even large volume flows of cooling liquid can safely pass from the swirl chamber into the area between the swirl chamber and the container housing, the wall of the swirl chamber can have a plurality of through-openings, each of which completely penetrates the wall in the thickness direction. At least two of the through-openings can be arranged at different circumferential positions around the swirl chamber axis. Additionally or alternatively, at least two of the through-openings can be arranged at different positions in a direction along the swirl chamber axis. Additionally or alternatively, at least two through-openings can have different shapes, for example circular and elliptical or round and polygonal, and / or different opening cross-sectional areas.

[0019] To better guide the flow of coolant in the swirl chamber, a flow guide plate is arranged inside the swirl chamber. To achieve a coolant flow that follows the inner wall surface, i.e. the inner surface of the swirl chamber wall, as closely as possible, the flow guide plate can run parallel to the inner wall surface of the swirl chamber at a distance from this inner wall surface. The flow guide plate extends only around a circumferential section, but not completely closed around the swirl chamber axis. Therefore, if the swirl chamber is a cylindrical swirl chamber, the flow guide plate is preferably a partially cylindrical flow guide plate. The flow guide plate preferably projects from the same base wall section along the swirl chamber axis as the swirl chamber wall. The flow guide plate is preferably curved around the swirl chamber axis or around an axis of curvature parallel to the swirl chamber axis.

[0020] Likewise, the flow guide plate preferably extends in the area of ​​the flow inlet into the swirl chamber, i.e., approximately along the swirl chamber axis in an axial region common to the outlet of the supply line. Since the flow guide plate is intended to influence the course of the coolant flow, preferably in its inlet area into the swirl chamber, it is sufficient if the flow guide plate extends only over part of the axial dimension of the swirl chamber relative to the swirl chamber axis. The flow guide plate is preferably located entirely within a supporting, particularly preferably injection-molded, container shell, as explained in more detail below.

[0021] In order to accelerate or decelerate the cooling liquid in the swirl chamber, a gap distance between the inner surface of the wall of the swirl chamber and a surface of the flow guide plate facing it along the flow path of the cooling liquid in the gap formed by the inner surface of the wall of the swirl chamber and the surface of the flow guide plate facing it, approximately in the circumferential direction around the swirl chamber axis and / or around an axis of curvature of the flow guide plate parallel to the swirl chamber axis, becomes smaller or larger.

[0022] In principle, it may be sufficient if the vortex chamber extends over only part of the space provided inside the container housing along the vortex chamber axis. However, to achieve the longest possible flow path within the vortex chamber, it is advantageous if the vortex chamber extends from the base wall section of the container housing along the vortex chamber axis to the end wall section of the container housing opposite the base wall section. The vortex chamber therefore preferably extends from the container bottom to the opposite container ceiling. Likewise, the flow guide plate, if present, is preferably formed only in the lower or only in the upper container shell. For the reasons stated above, the flow guide plate, if present, is preferably formed in that container shell which also shows the opening of the feed line into the vortex chamber.

[0023] The expansion tank can advantageously be formed by injection molding and, for example, comprise an upper and a lower tank shell. Preferably, the lower tank shell comprises the tank bottom and part of the side walls of the tank, and the upper tank shell comprises the tank ceiling and part of the side walls of the tank. In this preferred case, each tank shell comprises a part of the swirl chamber, with the respective part of the swirl chamber preferably being formed integrally with the tank shell containing it.

[0024] In principle, the area outside the vortex chamber, but inside the container housing, can be free of flow obstructions. However, the area inside the container housing, but outside the vortex chamber, is preferably divided into a plurality of communicating chambers. In the prior art, such chambers are referred to as expansion chambers, as they serve to absorb the temperature-related increase in volume of the coolant to a greater extent than the vortex chamber through which the flow occurs. The chambers are generally separated from one another by partition walls, whereby the area inside the container housing, but outside the vortex chamber, should be designed in such a way that a flow in the circumferential direction around the vortex chamber axis outside the vortex chamber is possible. The flow in the circumferential direction can, but does not have to, completely surround the vortex chamber.For this purpose, partition walls separating two adjacent chambers may have a communication opening through which cooling liquid can flow from one of the chambers into the adjacent other.

[0025] All partition walls can each have at least one communication opening, so that cooling fluid in the annular flow can flow around the outside of the vortex chamber multiple times. Alternatively, at least one partition wall can be free of a communication opening, in particular to physically separate an inlet-side interior region and / or the supply line from the outlet opening. The partition wall free of communication openings preferably extends completely between the container housing and the vortex chamber to achieve a complete physical interruption of the space outside the vortex chamber.

[0026] The communication openings of at least two partition walls can be arranged at different distances from the swirl chamber to promote degassing of the cooling liquid and / or can be arranged at different positions in a direction along the swirl chamber axis. This allows a flow of cooling liquid flowing macroscopically outside the swirl chamber to be superimposed with a flow radial and / or axial with respect to the swirl chamber axis. The cooling liquid flow can thus, for example, be directed spirally or helically from the swirl chamber to a wall, in particular a side wall, of the container housing, or the cooling liquid flow flowing around the swirl chamber outside the swirl chamber can, for example, approach the swirl chamber and a wall, in particular a side wall, of the container housing in sections in a type of superimposed pendulum motion.In addition to or as an alternative to the different locations of the communication openings, these can have different shapes and / or different cross-sectional areas, for example, to specifically alter the flow velocity. This further supports degassing.

[0027] Preferably, the planar partition walls extend with at least one of their main physical extension directions parallel to the vortex chamber axis—whereby for each planar partition wall, its thickness dimension is significantly shorter than its main physical extension directions, which are orthogonal to each other and to the respective local thickness direction. Although this is not mandatory, the formation of planar partition walls is preferred.

[0028] In principle, it can be envisaged that the partition walls extend along the swirl chamber axis only over a portion of the corresponding dimension of the swirl chamber. However, for careful degassing of the aforementioned large volume flows of coolant, it is preferable for partition walls separating two adjacent chambers to extend from a vessel bottom to a vessel ceiling opposite the vessel bottom.

[0029] The partition walls are also preferably formed in one piece with the container shells that support them using the injection molding process.

[0030] To achieve a cooling fluid flow in the tank housing with the longest possible flow path, the outlet opening is preferably located outside the swirl chamber in the tank housing. This ensures that the cooling fluid flows from the interior of the swirl chamber to the exterior of the swirl chamber in the tank housing.

[0031] The present application also relates to a motor vehicle, in particular a hybrid-electric or fully electric motor vehicle, comprising a cooling circuit with a coolant expansion tank configured as described above. The cooling circuit comprises a pump arrangement for generating a coolant flow in the cooling circuit, wherein the pump arrangement is configured to generate a coolant flow rate of at least 12 l / min, preferably at least 25 l / min, and even more preferably at least 35 l / min during intended normal cooling operation.

[0032] The present invention is explained in more detail below with reference to the accompanying drawings. It shows: Fig. 1 a sectional view through an expansion tank according to the invention along a cutting axis parallel to the vortex chamber axis, Fig. 2 a plan view of the inside of the lower tank shell of the expansion tank of Fig. 1, and Fig. 3 a perspective view of the interior of the lower container shell of Fig. 2.

[0033] In Fig. 1 shows an embodiment of a coolant expansion tank according to the invention, generally designated 10. The expansion tank 10 has a tank housing 12 and is formed from an upper tank shell 14 and a lower tank shell 16.

[0034] The upper container shell 14 comprises a container cover 18 and a closed, circumferential upper side wall 20 projecting integrally from the container cover 18 as sections of the container housing 12.

[0035] The lower container shell 16 comprises a container bottom 22 opposite the container ceiling 18 in the operational state of the expansion tank 10 and a closed, circumferential lower side wall 24 projecting integrally from the container bottom 22 as sections of the container housing 12. The upper and lower container shells 14 and 16 are connected to one another along a joining plane 26, in particular welded, for example by mirror welding or by another suitable welding process.

[0036] Functional formations are formed on the outside of the container shells 14 and 16, such as holders 28, 30 and 32 for fastening the expansion tank 10 to a structure surrounding it, in particular the structure of a vehicle V. A further functional formation is the sensor holder 34 which, in the example shown, passes through the upper container shell 14 and holds a sensor arrangement 36 for detecting operating states of the expansion tank 10 and / or properties of the coolant flowing through the expansion tank 10.

[0037] In the area of ​​the tank bottom 22, a pipe 38 formed integrally with the lower tank shell 14, as part of a supply line 40, guides coolant into the expansion tank 10. In the example shown, the pipe 38 and the supply line 40 advantageously run along a rectilinear supply axis Z, which is conceived to pass centrally through the pipe 38 and the supply line 40. The supply line 40 is part of a coolant circuit or cooling circuit 41 in the motor vehicle V. The cooling circuit 41 comprises a pump 39, which, during operation of the cooling circuit 41, generates coolant volume flows of between 30 and 50 l / min.

[0038] Both container shells 14 and 16 are injection-molded from thermoplastic material, preferably polyethylene or polypropylene.

[0039] The expansion tank 10 is in Fig. 1 in its operational spatial orientation. The arrow g indicates the direction of gravity, which runs parallel to the plane of the drawing of Fig. 1 and orthogonal to the plane of Fig. 2.

[0040] A cylindrical vortex chamber 42 is formed inside the expansion tank 10, extending continuously from the tank bottom 22 to the tank ceiling 18. To facilitate the description of the interior of the expansion tank 10, a virtual vortex chamber axis W is shown, which is conceived to pass centrally through the vortex chamber 42. Due to the cylindrical shape of the vortex chamber 42, the virtual vortex chamber axis W coincides with the cylindrical axis of the vortex chamber 42.

[0041] The wall 44 of the vortex chamber 42 is formed in two parts, each approximately equal in the upper container shell 14 and in the lower container shell 16. An upper vortex chamber wall 44a formed integrally with the upper container shell 14 and a lower vortex chamber wall 44b formed integrally with the lower container shell 16 meet at the joining plane 26 and are welded together there to form the wall 44 of the vortex chamber 42.

[0042] The supply line 40 passes through the lower side wall 24 and opens into the swirl chamber 42 at an orifice 46. Cooling liquid introduced into the swirl chamber 42 via the orifice 46 eccentrically with respect to the swirl chamber axis W flows when viewed from the Fig. 2 into the vortex chamber 42 and is deflected into a counterclockwise oriented vortex flow after hitting the inner surface of the wall 44.

[0043] The vortex chamber 42 extends with its lower vortex chamber wall 44b from a base wall section 44c to an end wall section 44d. The base wall section 44c is formed by a section of the container bottom 22, and the end wall section 44d is formed by a section of the container ceiling 18.

[0044] A flow guide plate 48 also extends along the vortex chamber axis W from the base wall section 44c. The flow guide plate 48 runs orthogonally to the vortex chamber axis W at a distance from the lower vortex chamber wall 44b. The flow guide plate 48, which is curved about an axis of curvature parallel to the vortex chamber axis W, does not extend to the joining plane 26 in the example shown, but ends at a distance from it. However, the flow guide plate 48 extends so far along the vortex chamber axis W that its longitudinal end, which is remote from the container bottom 22, is closer to the joining plane 26 than to the container bottom 22.

[0045] Although the flow guide plate 48 is curved around the vortex chamber axis W, it extends only incompletely around the vortex chamber axis W and does not rotate completely around it. The angle of rotation of the flow guide plate 48 around an axis P central to the flow guide plate 48 (see Fig. 2), which, in contrast to the illustrated embodiment, can be the vortex chamber axis W, is approximately 180°.

[0046] How to get into the Fig. 2 and Fig. 3, in the example shown the flow guide plate 48 is approximately partially cylindrical, with the cylinder axis P (see Fig. 2) the flow guide plate 48 is spaced apart from the vortex chamber axis W, so that the distance between the flow guide plate 48 and the opposite lower vortex chamber wall 44b along the circumferential extent of the two formations in a counterclockwise direction in Fig. 2 is reduced. The outlet opening 46 of the supply line 40 points to an area between the flow guide plate 48 and the lower swirl chamber wall 44b, in which the distance between them is greater. A cooling liquid introduced into the gap 49 between the flow guide plate 48 and the lower swirl chamber wall 44b thus flows, when viewed from Fig. 2 counterclockwise along the gap 49 and is accelerated by the gap size of the gap 49 decreasing along the flow path.

[0047] Cooling fluid can flow from the swirl chamber 42 into the external environment of the swirl chamber 42 between the wall 44 of the swirl chamber 42 and the container housing 12 via several through openings 50. In Fig. 1 only one through opening 50 can be seen. Fig. However, Figure 3 shows two through holes 50.

[0048] Expansion chambers 52 are formed outside the swirl chamber 42, of which two immediately adjacent expansion chambers 52 are each separated from one another by a flat partition 54. The partitions 54 also extend completely between the container bottom 22 and the container ceiling 18. Like the wall 44 of the swirl chamber 42, each partition 54 in the illustrated embodiment is formed by an upper partition 54a and a lower partition 54b, which contact one another in the joining plane 26 and are preferably connected to one another, particularly preferably by a material fit. Since the two container shells 14 and 16 are preferably produced by injection molding, the upper and lower partitions 54a and 54b, respectively, are formed integrally with the container housing 12 in the illustrated example, i.e. with the container ceiling 18, container bottom 22 and side walls 20 and 24.

[0049] In each partition wall 54 except for the partition wall between the supply line 40 and the outlet opening 58, whose lower partition wall 54b' is in the Fig. 2 and Fig. 3, a communication opening 56 is formed through which cooling liquid can flow from one side of the partition wall 54 to the other side of the partition wall 54.

[0050] The vortex chamber 42 is formed at a distance from the container housing 12 in every direction orthogonal (radial) to the vortex chamber axis W. Through the communication openings 56, a flow of cooling fluid in the circumferential direction around the vortex chamber axis W is possible.

[0051] In the Fig. 2 and Fig.3 shows the outlet opening 58 through which coolant can escape from the expansion tank 10. The outlet opening 58 opens directly into an expansion chamber 52', so that coolant must necessarily flow from the swirl chamber 42 into the expansion chamber 52' ​​with the outlet opening 58 in order to be able to leave the expansion tank 10 again.

[0052] In order to increase the flow path and thus the residence time of the coolant in the expansion tank 10, the swirl chamber 42 has no through openings 50 to the expansion chamber 52' ​​with the outlet opening 58 and to the expansion chamber 52" adjacent to this expansion chamber 52' ​​opposite to the swirl direction of the coolant in the swirl chamber 42. However, the swirl chamber 42 has a through opening 50 in each of the other expansion chambers 52 adjacent to the swirl chamber 42.

[0053] The partition wall 54 between the outlet opening 58 and the supply line 40 does not have a communication opening 56. It extends completely over the entire cross-sectional area of ​​the interior space between the swirl chamber 42 and the container housing 12. All other partition walls 54 each have a communication opening 56. Thus, all expansion chambers 52 communicate with each other, with the exception of the immediately adjacent expansion chambers 52, through which the supply line 40 runs, and the expansion chamber 52', in which the outlet opening 58 is located.

Claims

[1] Coolant expansion tank (10) for arrangement in a coolant circuit (41), comprising: - a container housing (12), - a vortex chamber (42) in the container housing (12) - a supply line (40) for introducing cooling liquid into the container housing (12), and - an outlet opening (58) for discharging cooling liquid from the container housing (12), wherein the supply line (40) opens into the vortex chamber (42), wherein the vortex chamber (42) is defined by a wall (44) projecting along a vortex chamber axis (W) from a base wall section (44c) of the container housing (12), encircling the vortex chamber axis (W) in a closed manner, which wall is arranged at a distance from the container housing (12) in each direction orthogonal to the vortex chamber axis (W), characterized byin that a flow guide plate (48) is arranged in the interior of the swirl chamber (42), and the flow guide plate (48) extends only around a circumferential section, but not completely closed, around the swirl chamber axis (W), wherein a gap (49) is formed between the inner surface of the wall of the swirl chamber (42) and a surface of the flow guide plate (48) facing the wall of the swirl chamber (42), the gap (49) has a gap spacing along a flow path of the cooling liquid in the gap (49), and wherein the gap spacing becomes smaller or larger in the circumferential direction around the swirl chamber axis (W) in order to accelerate or decelerate the cooling liquid in the swirl chamber (42). [2] Coolant expansion tank (10) according to claim 1, characterized by that the vortex chamber (42) is accommodated in the container housing (12) with its outer side in the circumferential direction so that cooling liquid can flow around it completely. [3] Coolant expansion tank (10) according to claim 2, characterized by that the wall (44) of the vortex chamber (42) has at least one through-opening (50) which completely penetrates the wall (44) in the thickness direction. [4] Coolant expansion tank (10) according to claim 3, characterized by in that the wall (44) of the swirl chamber (42) has a plurality of through-openings (50) which completely penetrate the wall (44) in the thickness direction, wherein at least two of the through-openings (50) are arranged at different circumferential positions around the swirl chamber axis (W) in the circumferential direction and / or are arranged at different positions in a direction along the swirl chamber axis (W) and / or have different shapes and / or different opening cross-sectional areas. [5] Coolant expansion tank (10) according to one of claims 1-4, characterized bythat the flow guide plate (48) runs parallel to an inner wall surface of the vortex chamber (42) at a distance therefrom. [6] Coolant expansion tank (10) according to one of the preceding claims, characterized by that the vortex chamber (42) extends from the base wall section (44c) of the container housing (12) along the vortex chamber axis (W) to the end wall section (44d) of the container housing (12) opposite the base wall section (44c). [7] Coolant expansion tank (10) according to one of the preceding claims, characterized by that the area inside the container housing (12), but outside the vortex chamber (42), is divided into a plurality of chambers (52, 52', 52") communicating with each other. [8] Coolant expansion tank (10) according to claim 7, characterized byin that partition walls (54) which separate two adjacent chambers (52, 52', 52") from one another have a communication opening (56) through which cooling liquid can flow from one of the chambers (52, 52', 52") into the other, wherein the communication openings (56) of at least two partition walls (54) are arranged at different distances from the swirl chamber (42) and / or are arranged at different positions in a direction along the swirl chamber axis (W) and / or have different shapes and / or different opening cross-sectional areas. [9] Coolant expansion tank (10) according to one of claims 7 or 8, characterized by that partition walls (54) which separate two adjacent chambers (52, 52', 52") from one another extend from a container bottom (22) to a container ceiling (18) opposite the container bottom (22). [10] Coolant expansion tank (10) according to one of the preceding claims, characterized by that the outlet opening (58) is formed outside the vortex chamber (42) in the container housing (12). [11] Motor vehicle (V) with a cooling liquid circuit (41) with a cooling liquid expansion tank (10) according to one of the preceding claims, characterized by that the cooling liquid circuit (41) comprises a pump (39) which, in normal operation as intended, is designed to achieve a cooling liquid flow of more than 12 l / min.

Images