gas-liquid separation mechanism of the reserve tank

Abstract

To provide a gas-liquid separation mechanism of a reserve tank capable of efficiently separating bubbles contained in a coolant by a simple structure.SOLUTION: A gas-liquid separation mechanism for separating air bubbles contained in a coolant flowing into a reserve tank 13 provided in a circulating path of the coolant includes: a coolant inlet opening 14a provided in a first side wall 13A of the reserve tank 13; a coolant outlet opening 15a provided in a second side wall 13B opposed to the first side wall 13A; a bubble discharge port 17a provided in an upper wall 13D of the reserve tank 13 to discharge bubbles separated from the coolant; flow adjusting means 16 for adjusting the flow of the coolant flowing in from the inlet opening 14a so that the coolant rises and flows back; and a first small wall part 18 projected downward from the upper wall 13D of the reserve tank 13 in the vicinity of the bubble discharge port 17a and on a downstream side in a backflow direction to the bubble discharge port.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a gas-liquid separation mechanism for a reserve tank provided in a coolant circulation path. [Background Art]

[0002] For example, a vehicle is provided with a cooling system that cools heat-generating devices such as an engine and a power converter by circulating a coolant. In this cooling system, the heat-generating device is cooled when the coolant circulates through a circulation path forming a closed loop. The coolant, which has been heated after cooling the heat-generating device, is cooled by heat exchange with outside air in a heat exchanger such as a radiator, and the coolant whose temperature has decreased after this cooling is reused to cool the heat-generating device. By continuously repeating such an operation, the heat-generating device is cooled and its temperature is kept below a predetermined value.

[0003] A reserve tank for storing coolant is provided on the upstream side of the liquid pump in the coolant circulation path. This reserve tank functions to replenish the cooling circuit with coolant and absorb volume changes caused by thermal expansion of the coolant. The reserve tank is provided with a gas-liquid separation mechanism for separating and removing air bubbles contained in the coolant. In this cooling system, before the coolant is sucked into the liquid pump, air bubbles contained in the coolant are separated and removed from the coolant by the gas-liquid separation mechanism, thereby preventing suction of air bubbles by the liquid pump and preventing occurrence of malfunctions of the liquid pump caused by suction of air bubbles.

[0004] As a reserve tank equipped with a gas-liquid separation mechanism, for example, Patent Document 1 describes an expansion tank comprising a tank body that partitions a storage chamber for storing coolant, and having a coolant outlet at the bottom of the tank body that opens toward the storage chamber. The tank body has an opening that opens downward toward the coolant outlet, and an internal structure that defines a pressure chamber that is open toward the storage chamber only by this opening. With such an expansion tank, it is possible to suppress the generation of swirling flow and prevent a large amount of bubbles from flowing out into the coolant circulation path all at once without increasing the size of the tank body.

[0005] Furthermore, Patent Document 2 proposes a reserve tank comprising a gas-liquid separation section having an internal space for separating gas and liquid cooling water, an inlet section having an opening for supplying cooling water to the internal space, an outlet section having an opening for discharging cooling water from the internal space, and a projection section that protrudes upward from the bottom of the internal space. In this reserve tank, the portion between the inner circumferential surface of the gas-liquid separation section and the outer circumferential surface of the projection section forms an annular flow path. This reserve tank can stably perform both the function of preventing the generation of bubbles and the function of removing bubbles.

[0006] Furthermore, Patent Document 3 proposes a reserve tank comprising a gas-liquid separation section, an inlet section, an outlet section, and a cylindrical projection. Here, the gas-liquid separation section is formed in a bottomed cylindrical shape around a predetermined axis, the inlet section allows cooling water to flow into the gas-liquid separation section, and the projection is formed to extend from the bottom wall of the gas-liquid separation section along a predetermined axis. In addition, at the tip of the projection, the internal space of the projection opens into the internal space of the gas-liquid separation section. Such a reserve tank can stably perform both the function of suppressing the generation of bubbles and the function of removing bubbles. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2017-078399 [Patent Document 2] Japanese Patent Publication No. 2020-186684 [Patent Document 3] Japanese Patent Publication No. 2021-169815 [Overview of the project] [Problems that the invention aims to solve]

[0008] However, the reserve tanks proposed in Patent Documents 1 to 3 all suffer from the problem of high manufacturing costs due to the complex structure of the gas-liquid separation mechanism.

[0009] The present invention has been made in view of the above problems, and its object is to provide a gas-liquid separation mechanism for a reserve tank that can efficiently separate air bubbles contained in the coolant with a simple configuration. [Means for solving the problem]

[0010] To achieve the above objective, one embodiment of the present invention is a gas-liquid separation mechanism for separating air bubbles contained in coolant flowing into a reserve tank provided in a coolant circulation path, comprising: an inlet opening for the coolant provided in a first side wall of the reserve tank; an outlet opening for the coolant provided in a second side wall facing the first side wall; a bubble outlet provided in the upper wall of the reserve tank for discharging air bubbles separated from the coolant; a flow adjustment means for adjusting the flow of the coolant flowing in from the inlet opening to rise and flow backward; and a first small wall portion projecting downward from the upper wall of the reserve tank near the bubble outlet and downstream of the bubble outlet in the direction of backward flow. Furthermore, it includes a second small wall portion projecting downward from the upper wall, located upstream of the bubble outlet in the direction of reverse flow. It is characterized by the following: Furthermore, one embodiment of the present invention is a gas-liquid separation mechanism for separating air bubbles contained in coolant flowing into a reserve tank provided in a coolant circulation path, comprising: an inlet opening for the coolant provided in a first side wall of the reserve tank; an outlet opening for the coolant provided in a second side wall facing the first side wall; a bubble outlet provided in the upper wall of the reserve tank for discharging air bubbles separated from the coolant; a flow adjustment means for adjusting the flow of the coolant flowing in from the inlet opening to rise and flow backward; and a first small wall portion projecting downward from the upper wall of the reserve tank near the bubble outlet and downstream of the bubble outlet in the direction of backward flow, wherein the flow adjustment means is provided downstream of the main flow of the coolant from the inlet opening to the outlet opening relative to the bubble outlet, and comprises a bottom small wall portion projecting upward from the bottom wall of the reserve tank. [Effects of the Invention]

[0011] According to the present invention, it is possible to efficiently separate air bubbles contained in the coolant with a simple configuration. [Brief Description of Drawings]

[0012] [Figure 1] Figure 1 is a conceptual longitudinal sectional view of a reserve tank (sub-tank) provided with a gas-liquid separation mechanism according to one embodiment of the present invention. [Figure 2] Figure 2 is a conceptual sectional view taken along line X-X in Figure 1. [Figure 3] Figure 3 is a conceptual sectional view taken along line Y-Y in Figure 1. [Figure 4A] Figure 4A is a conceptual longitudinal sectional view of the reserve tank showing the action of the gas-liquid separation mechanism. [Figure 4B] Figure 4B is a conceptual longitudinal sectional view of the reserve tank showing the action of the gas-liquid separation mechanism. [Figure 4C] Figure 4C is a conceptual longitudinal sectional view of the reserve tank showing the action of the gas-liquid separation mechanism. [Figure 5] Figure 5 is a conceptual partial longitudinal sectional view of a reserve tank showing a first modified example of the present invention. [Figure 6] Figure 6 is a conceptual partial longitudinal sectional view of a reserve tank showing a second modified example of the present invention. [Figure 7] Figure 7 is a conceptual partial longitudinal sectional view of a reserve tank showing a third modified example of the present invention. [Figure 8] Figure 8 is a block diagram showing the configuration of a cooling system installed in a vehicle. [Mode for Carrying Out the Invention]

[0013] Embodiments of the present invention will be described below based on the accompanying drawings.

[0014] [Configuration of Cooling System] The configuration of a cooling system (installed in a vehicle) including a reserve tank, which is an application example of the gas-liquid separation mechanism according to one embodiment of the present invention, will be described below based on Figure 8.

[0015] FIG. 8 is a block diagram showing a circulation path of coolant in a cooling system. The illustrated cooling system 100 cools the power conversion device 130, which is a heat-generating device, and the oil cooler 140 by circulating coolant through a circulation path forming a closed loop, and keeps their temperatures at or below a predetermined value. Here, the power conversion device 130 includes an inverter (INV), a DC / DC converter, an on-board charger (OBC), and the like. As the coolant, for example, a liquid (antifreeze) mainly containing ethylene glycol, which has high thermal conductivity and is not easily frozen, is used.

[0016] Here, a liquid pump 110 for circulating the coolant is provided in the circulation path, and a radiator 120, the power conversion device 130, the oil cooler 140, and the sub-tank 13 of the reserve tank 11 are sequentially arranged along the flow direction of the coolant discharged from the liquid pump 110. A pipe 111 extending from the discharge side of the liquid pump 110 is connected to the inlet side of the radiator 120, and a pipe 112 extending from the outlet side of the radiator 120 is connected to the inlet side of the power conversion device 130. A pipe 113 extending from the outlet side of the power conversion device 130 is connected to the inlet side of the oil cooler 140, and a pipe 114 extending from the outlet side of the oil cooler 140 is connected to the inlet side of the sub-tank 13. Furthermore, a pipe 115 extending from the outlet side of the sub-tank 13 is connected to the suction side of the liquid pump 110. The radiator 120 is provided with an electric radiator fan 121 for allowing outside air to pass through the radiator 120 to promote heat exchange between the coolant and the outside air.

[0017] In the present embodiment, the reserve tank 11 is divided into a main tank 12 and a sub-tank 13, and the gas-liquid separation mechanism 10 is provided in the sub-tank 13. Here, the sub-tank 13 is provided in the circulation path as described above, and the main tank 12 is arranged at a position above the sub-tank 13. The main tank 12 and the sub-tank 13 are communicated with each other by a communication pipe 116.

[0018] In the cooling system 100 configured as described above, when the liquid pump 110 is driven by a portion of the power from an electric motor (not shown) or an engine (not shown), the liquid pump 110 circulates the coolant through a closed-loop cooling path as shown by the arrows in Figure 8. The heat-generating equipment, the power converter 130 and the oil cooler 140, are cooled by the circulating coolant, thereby keeping their temperatures below a predetermined value.

[0019] In other words, the coolant pressurized by the liquid pump 110 is discharged from the discharge side of the liquid pump 110 into the piping 111, and then introduced into the radiator 120 from the piping 111. As the coolant introduced into the radiator 120 flows through it, it is cooled by heat exchange with the outside air passing through the radiator 120 due to the airflow action of the rotating radiator fan 121.

[0020] The coolant, cooled in the radiator 120, flows from the outlet side of the radiator 120 to the pipe 112, and from this pipe 112 is introduced into the power converter 130. The power converter 130 is then cooled as the coolant flows through it, and the coolant that has been used for cooling flows from the outlet side of the power converter 130 to the pipe 113. The coolant is then introduced into the oil cooler 140 from the pipe 113, and the oil is cooled as the coolant flows through the oil cooler 140.

[0021] As described above, the oil is cooled by passing through the oil cooler 140, and the coolant, whose temperature has risen due to heat exchange, flows from the outlet side of the oil cooler 140 to the pipe 114, and from this pipe 114 is introduced into the sub-tank 13. Here, the sub-tank 13 is equipped with a gas-liquid separation mechanism 10, which will be described later in Figure 1. The air bubbles contained in the coolant that flows into the sub-tank 13 are removed by the gas-liquid separation mechanism 10. The coolant from which the air bubbles have been removed by the gas-liquid separation mechanism 10 flows from the outlet side of the sub-tank 13 to the pipe 115, and is drawn from the pipe 115 to the suction side of the liquid pump 110 and pressurized. Subsequently, the described process is repeated continuously, so that the heat-generating equipment, the power converter 130 and the oil cooler 140, are continuously cooled, and their temperatures are kept below a predetermined value.

[0022] In the above-described example of the application of the coolant circulation path, the power converter 130 and the oil cooler 140 were given as heat-generating equipment to be cooled, but the equipment to be cooled may also be the engine or other auxiliary equipment.

[0023] [Configuration of the sub-tank and gas-liquid separation mechanism] Next, the configuration of the sub-tank 13 and the gas-liquid separation mechanism 10 according to an embodiment of the present invention provided in the sub-tank 13 will be described with reference to Figures 1 to 3. Figure 1 is a longitudinal cross-sectional view of the sub-tank 13 equipped with the gas-liquid separation mechanism 10 according to an embodiment of the present invention, Figure 2 is a cross-sectional view along line XX of Figure 1, and Figure 3 is a cross-sectional view along line YY of Figure 1.

[0024] The gas-liquid separation mechanism 10 comprises a sub-tank 13 which is a reserve tank 11, an inlet opening 14a and an outlet opening 15a for cooling water provided in the sub-tank 13, a bubble outlet 17a for discharging bubbles separated from the cooling liquid, and a flow adjustment means. The flow adjustment means adjusts the flow of the cooling liquid flowing in from the inlet opening 14a so that it rises and flows backward, and in this embodiment, the flow adjustment means is provided with a small bottom wall portion 16. The gas-liquid separation mechanism 10 further comprises a first small wall portion 18 and a second small wall portion 19. The configurations of the gas-liquid separation mechanism 10 will be described in detail below. In the following description, the bubble outlet 17a will also be simply referred to as "outlet 17a".

[0025] The sub-tank 13 shown in Figure 1 is a tank formed in a roughly rectangular box shape, comprising a first side wall 13A with an inlet opening 14a and a second side wall 13B positioned opposite the first side wall 13A and having an outlet opening 15a. The sub-tank 13 also comprises a bottom wall 13C that forms the bottom surface of the tank and an upper wall 13D that forms the ceiling surface of the tank. An outlet 17a is provided in the upper wall 13D. The first side wall 13A and the second side wall 13B are roughly vertical wall sections positioned on the upstream side (right side in Figure 1) and downstream side (left side in Figure 1) of the main flow of cooling water in the circulation path. At the center of the width direction (perpendicular to the plane of the paper in Figure 1, and vertical direction in Figures 2 and 3) of the lower part of the first and second side walls 13A and 13B, respectively, circular cylindrical nipples 14 and 15, which constitute the inlet and outlet passages, are connected roughly horizontally, respectively. Then, the pipes 114 and 115 shown in Figure 8 are connected to each of the nipples 14 and 15, respectively.

[0026] Here, the connection portion of one nipple 14, which constitutes the inlet passage, to the first side wall 13A on the upstream side of the sub-tank 13 is configured as a circular inlet opening 14a. The connection portion of the other nipple 15, which constitutes the outlet passage, to the sub-tank 13 is configured as a circular outlet opening 15a at the lower part of the second side wall 13B on the downstream side. Therefore, the inlet opening 14a and the outlet opening 15a open opposite each other in the direction of coolant flow.

[0027] Furthermore, a small bottom wall portion 16 is provided inside the sub-tank 13. The small bottom wall portion 16 is located downstream of the main flow of coolant from the inlet opening 14a to the outlet opening 15a relative to the discharge port 17a, and protrudes upward from the bottom wall 13C of the sub-tank 13 into the sub-tank 13. In this embodiment, a plate-shaped small bottom wall portion 6 is provided as a vertical wall, protruding almost vertically from the inner surface of the bottom wall 13C of the sub-tank 13, near the downstream outlet opening 15a. This small bottom wall portion 16 constitutes a flow adjustment means that adjusts the flow of coolant flowing into the sub-tank 13 from the inlet opening 14a to be directed upward. As shown in Figures 2 and 3, the small bottom wall portion 16 in this embodiment is arranged almost parallel to the first side wall 13A and the second side wall 13B across the entire width of the sub-tank 13.

[0028] As shown in Figure 1, the height h3 of the bottom wall portion 16 is set to be less than or equal to the center height h0 of the outlet opening 15a (height from the bottom surface of the sub-tank 13 to the center of the outlet opening 15a) (h3 ≤ h0) so that the bottom wall portion 16 does not excessively obstruct the main flow of coolant flowing out of the outlet opening 15a. As an example, in this embodiment, the height h3 of the bottom wall portion 16 is set to about 1 / 4 to 1 / 5 of the height H of the sub-tank 13 (H / 5 ≤ h3 ≤ H / 4). In this embodiment, the bottom wall portion 16 is used as a flow adjustment means, but the configuration of the flow adjustment means is not limited to this. For example, as a flow adjustment means, the downstream nipple 15 that constitutes the outlet flow path can be offset to a higher position than the upstream nipple 14 that constitutes the inlet flow path, or the upstream nipple 14 can be connected so that it faces diagonally upward toward the inside of the sub-tank 13.

[0029] By providing the bottom small wall portion 16, the cooling liquid flowing inside the sub-tank 13 is adjusted so that, as shown in Figures 4A and 4B, it hits the bottom small wall portion 16 and rises, and then flows in a reverse direction in the upper part of the sub-tank 13, thus creating a vertical vortex.

[0030] A circular, cylindrical nipple 17 is connected almost vertically to the upper wall 13D of the sub-tank 13, near the upstream side (to the right in Figure 1) in the center of the width direction. One end of the connecting pipe 116 shown in Figure 8 is connected to this nipple 17. This nipple 17 opens into the upper wall 13D of the sub-tank 13 as a circular outlet 17a to discharge air bubbles separated from the coolant.

[0031] The first small wall portion 18 and the second small wall portion 19, which constitute the gas-liquid separation mechanism 10, are each projecting downward from the upper wall 13D of the sub-tank 13. The first small wall portion 18 and the second small wall portion 19 of this embodiment will be described in detail below.

[0032] On the inner surface of the upper wall 13D of sub-tank 3, in the portion upstream of the outlet 17a (the right portion in Figure 1; downstream of the outlet 17a in the direction in which the cooling water flows backward due to the flow adjustment means), a rectangular plate-shaped first small wall portion 18 is provided as a vertical wall to retain and catch air bubbles, projecting approximately vertically downward. Similarly, on the upper wall 13D of sub-tank 13, in the portion downstream of the main flow of the cooling water from the outlet 17a (the left portion in Figure 1; upstream of the outlet 17a in the direction in which the cooling water flows backward), a rectangular plate-shaped second small wall portion 19 is provided as a vertical wall to suppress turbulence in the cooling liquid guided upward by the bottom small wall portion 16, projecting approximately vertically downward.

[0033] Here, the rectangular plate-shaped first small wall section 18 and the second small wall section 19 are arranged approximately parallel to the first side wall 13A and the second side wall 13B, respectively, across the entire width of the sub-tank 13, as shown in Figure 2. In this embodiment, as an example, the height h1 of the first small wall section 18 and the height h2 of the second small wall section 19 are set to be equal (h1=h2). Similar to the height h3 of the bottom small wall section 6, as an example, in this embodiment, the height h1 of the first small wall section 18 and the height h2 of the second small wall section 19 are set to approximately 1 / 4 to 1 / 5 of the total height H of the sub-tank 3 (H / 5≦h1=h2≦H / 4). The heights h1 and h2 of each small wall section may be different.

[0034] The heights h1 and h2 of the first and second small wall sections 18 and 19, and the height h3 of the bottom small wall section 16 are not limited to the above range and can be changed as appropriate. For example, the heights h1 and h2 of the first and second small wall sections 18 and 19 may be different. In this embodiment, the small wall sections 16, 18, and 19 are arranged over the entire width of the sub-tank 13, but this is not limited to the case, and they may be installed to be arranged over only a part of the width. For example, the bottom small wall section 16 may be positioned on a straight line extending from the inlet opening 14a to the outlet opening 15a and erected to create an upward flow.

[0035] In the sub-tank 13 configured as described above, the gas-liquid separation mechanism 10 is formed by the bottom small wall portion 16, the first small wall portion 18, and the second small wall portion 19. The configuration of the main tank 12 is not shown or described, but an opening for replenishing the coolant is formed at the upper end of the main tank 12, and this opening is closed by a cap. A valve (relief valve) is provided on the cap. As described later, the gas bubbles separated from the coolant by the gas-liquid separation mechanism 10 in the sub-tank 13 are introduced into the main tank 12 through the connecting pipe 116 by buoyancy, and when the internal pressure of the main tank 12 exceeds a predetermined value, the valve provided on the cap opens and the air in the main tank 12 is discharged into the atmosphere.

[0036] [Operation of the gas-liquid separation mechanism] Next, the operation of the gas-liquid separation mechanism according to the present invention will be explained below with reference to Figures 4A to 4C.

[0037] Figures 4A to 4C are longitudinal cross-sectional views of the sub-tank 13 showing the operation of the gas-liquid separation mechanism according to the present invention. The coolant used to cool the heat-generating equipment, the power converter 130 and the oil cooler 140, flows almost horizontally as the main stream into the lower part of the sub-tank 13 from the inlet opening 14a of the upstream nipple 14, as shown in Figure 4A. Then, as the main stream of coolant that has flowed into the lower part of the sub-tank 13 flows toward the downstream outlet opening 5a, a portion of it is guided upward by the bottom small wall portion 16, and the rest of the coolant is drawn from the outlet opening 15a through the downstream nipple 15 and through the piping 115 shown in Figure 8 to the suction side of the liquid pump 110.

[0038] As described above, when a portion of the coolant that flows into the lower part of the sub-tank 13 from the inlet opening 14a is guided upward by the bottom wall portion 16, the large and small bubbles 21 contained in this coolant also move upward, as shown in Figure 4A. Furthermore, within the sub-tank 13, the coolant that has been guided upward by the bottom wall portion 16 flows backward from the outlet opening 15a towards the inlet opening 14a in the upper part of the sub-tank 13, generating a longitudinal vortex (tumble).

[0039] As described above, vertical vortices are generated in the sub-tank 13 due to the flow of the coolant. However, in the upper part of the sub-tank 13, a first small wall section 18 and a second small wall section 19 are provided on the upstream and downstream sides of the outlet 17a of the upper wall 13D of the sub-tank 13, respectively. Due to the flow straightening effect of these first small wall sections 18 and second small wall sections 19, the flow of the coolant in the upper part of the sub-tank 13 near the outlet 17a is not significantly affected by the vertical vortices. Therefore, air bubbles 21 contained in the coolant moving towards the upper part of the sub-tank 13 remain in the upper part of the sub-tank 13, and some of them are collected by buoyancy as they flow from the outlet 17a through the nipple 17 and the connecting pipe 116 shown in Figure 8 into the main tank 12 shown in Figure 8. Furthermore, as a result of the bubbles 21 being collected in the main tank 12, if the internal pressure of the main tank 12 exceeds a predetermined value, a valve (relief valve) provided in a cap (not shown) of the main tank 12 opens, as described above, and air is discharged into the atmosphere.

[0040] Furthermore, a space S is formed in the upper corner of the sub-tank 13, partitioned by the first small wall portion 18. As shown in Figure 4B, bubbles 21 that remain in the upper part of the sub-tank 13 flow into the space S within the sub-tank 13, forming an air layer in the space S, and its volume gradually increases. The larger bubbles 20 in space S then catch smaller bubbles 21 that approach them, and their volume gradually increases. As the larger bubbles 20 in space S continue to catch smaller bubbles 21 in their vicinity and grow larger, and their volume exceeds the volume of space S, as shown in Figure 4C, some of the bubbles 20 22 in space S flow out of space S over the first small wall portion 8, and flow from the outlet 17a through the nipple 17 and the connecting pipe 116 shown in Figure 8 into the main tank 12, where they are collected by the main tank 12.

[0041] As the above process is repeated, the separation of air bubbles contained in the coolant that flows into the sub-tank 13 from the coolant is promoted. As a result of the air bubbles separated from the coolant being collected by the main tank 12, the amount of air bubbles contained in the coolant that flows out from the sub-tank 13 into the piping 115 shown in Figure 8 and is drawn into the liquid pump 110 can be reduced. Therefore, malfunctions caused by air intake in the liquid pump 110 are prevented, and stable operation of the liquid pump 110 is ensured.

[0042] In the gas-liquid separation mechanism 10 of this embodiment described above, a rectangular plate-shaped bottom wall portion 16 is provided protruding from the bottom wall 13C of the sub-tank 13 as a flow adjustment means, and a rectangular plate-shaped first wall portion 18 and a second wall portion 19 are provided protruding from the top wall 13D of the sub-tank 13, resulting in a simple structure. Therefore, the structure for gas-liquid separation can be simplified, and the structure of the sub-tank 13 equipped with the gas-liquid separation mechanism 10 can also be simplified, thereby keeping its manufacturing cost low.

[0043] Furthermore, in the cooling system 100 according to this embodiment, the reserve tank 11 is divided into a main tank 12 and a sub-tank 13, and a gas-liquid separation mechanism 10 is provided in the sub-tank 13. This configuration allows for a simplification and miniaturization of the main tank 12. In addition, since the sub-tank 13 can be filled with coolant, the problem of air being drawn into the liquid pump 110 can be effectively solved.

[0044] [Differentiation] Next, a modified example of the present invention will be described.

[0045] (Variation 1) In the above embodiment, the first small wall portion 18, which constitutes part of the gas-liquid separation mechanism 10, is provided projecting vertically downward from the inner surface of the upper wall 31D of the sub-tank 13. However, as shown in Figure 5, the first small wall portion 18 may be provided projecting at an angle, with its lower end pointing towards the center of the discharge port 17a.

[0046] As described above, by providing the first small wall portion 18 at an angle, the volume of the space S defined in the upper part of the sub-tank 13 by the first small wall portion 18 can be increased, and a large amount of bubbles 20 can be stored in this space S. Furthermore, when the bubbles 20 stored in this space S are discharged from space S, the bubbles 20 can be smoothly guided along the inclined surface of the first small wall portion 18 to the discharge port 17a.

[0047] (Modification 2) In the above embodiment, the second small wall portion 19, which constitutes part of the gas-liquid separation mechanism 10, is provided projecting vertically downward from the inner surface of the upper wall 13D of the sub-tank 13. However, as shown in Figure 6, the second small wall portion 19 may be provided projecting at an angle, with its lower end pointing towards the center of the discharge port 17a.

[0048] As described above, by providing the second small wall portion 19 at an angle, turbulence in the coolant guided upward by the bottom small wall portion 16, which is a flow adjustment means, can be effectively suppressed.

[0049] (Variation 3) In this modified example, as shown in Figure 7, the bottom small wall portion 16 constituting the flow adjustment means has a smooth circular concave curved surface 16a on the side (upstream side) that is struck and guided by the coolant. By adopting such a curved surface configuration for the bottom small wall portion 16, the main flow of coolant flowing from the inlet opening 14a into the lower part of the sub-tank 13 can be efficiently and smoothly guided upward, generating a longitudinal vortex within the sub-tank 13.

[0050] Although the above description concerns an application of the present invention to a gas-liquid separation mechanism 10 of a reserve tank 11 (sub-tank 13) provided in a vehicle cooling system 100, the present invention is similarly applicable to gas-liquid separation mechanisms of reserve tanks provided in any cooling system other than a vehicle.

[0051] Furthermore, in the embodiments described above, an example was described in which the reserve tank 11 is divided into two parts, a main tank 12 and a sub-tank 13, and a gas-liquid separation mechanism is provided in the sub-tank 13. However, the present invention can also be applied to a gas-liquid separation mechanism provided in a single reserve tank.

[0052] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible without departing from the spirit of the invention. [Explanation of Symbols]

[0053] 10 Gas-liquid separation mechanism 11 Reserve Tank 12 Main Tanks 13 Sub-tank 13A First side wall 13B Second side wall 13C bottom wall 13D upper wall 14 Nipples 14a Entrance opening 15 Nipples 15a Exit opening 16. Bottom small wall section (flow adjustment means) 16a Circular concave surface of the small wall at the bottom 17 Nipple 17a Air bubble outlet 18. First small wall section 19. Second small wall section 100 Cooling System 110 Liquid pump 116 Communication pipe 120 Radiator 130 Power converter 140 Oil Cooler

Claims

1. A gas-liquid separation mechanism for separating air bubbles contained in coolant flowing into a reserve tank provided in the coolant circulation path, The coolant inlet opening provided in the first side wall of the reserve tank, and the coolant outlet opening provided in the second side wall facing the first side wall, A bubble outlet is provided on the upper wall of the reserve tank for discharging bubbles separated from the coolant, A flow adjustment means for adjusting the flow of the coolant that flows in from the inlet opening to rise and flow in reverse, A first small wall portion is provided projecting downward from the upper wall of the reserve tank, near the bubble outlet and downstream of the bubble outlet in the direction of reverse flow, Equipped with, A gas-liquid separation mechanism for a reserve tank, characterized by having a second small wall portion projecting downward from the upper wall on the upstream side of the bubble outlet in the direction of reverse flow.

2. A gas-liquid separation mechanism for separating air bubbles contained in coolant flowing into a reserve tank provided in the coolant circulation path, The coolant inlet opening provided in the first side wall of the reserve tank, and the coolant outlet opening provided in the second side wall facing the first side wall, A bubble outlet is provided on the upper wall of the reserve tank for discharging bubbles separated from the coolant, A flow adjustment means for adjusting the flow of the coolant that flows in from the inlet opening to rise and flow in reverse, A first small wall portion is provided projecting downward from the upper wall of the reserve tank, near the bubble outlet and downstream of the bubble outlet in the direction of reverse flow, Equipped with, The gas-liquid separation mechanism for a reserve tank is characterized in that the flow adjustment means is provided downstream of the main flow of the coolant from the inlet opening to the outlet opening with respect to the bubble outlet, and comprises a small bottom wall portion projecting upward from the bottom wall of the reserve tank.

3. The gas-liquid separation mechanism for a reserve tank according to claim 1 or 2, characterized in that the first small wall portion is provided with its lower end inclined toward the center of the bubble outlet.

4. The gas-liquid separation mechanism for a reserve tank according to claim 1, characterized in that the second small wall portion is provided with its lower end inclined toward the center of the bubble outlet.

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