Structure for inflow part of reserve tank

Abstract

To provide a structure for an inflow part of a reserve tank capable of suppressing inclusion of air in a coolant.SOLUTION: In a structure for an inflow part 52 of a reserve tank 5 provided in a coolant circulation circuit, when a side close to a reserve tank body 51 in the inflow part 52 is defined as one end side and a side far from the reserve tank body 51 is defined as the other end side, a flow passage area on the one end side in the inflow part 52 is set larger than that on the other end side. A shape of a flow passage inside the inflow part 52 is a tapered shape in which the flow passage area gradually becomes larger from the other end side toward the one end side.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a structure of an inlet portion of a reserve tank provided in a coolant circulation circuit. [Background technology]

[0002] Conventionally, as disclosed in, for example, Patent Document 1, a vehicle is provided with a coolant circulation circuit for cooling a device that generates heat (a heat generating component), and the device is cooled by the coolant circulating through the coolant circulation circuit. The coolant circulation circuit is also provided with a reserve tank. The reserve tank is used to replenish the coolant circulation circuit with coolant, and also has the function of absorbing volumetric changes caused by thermal expansion of the coolant.

[0003] If air gets mixed into the coolant in the reserve tank, there is a possibility that the air will flow out into the coolant circulation circuit, resulting in a deterioration in the cooling efficiency of the device.

[0004] In consideration of this point, Patent Document 2 and Patent Document 3 have been proposed. Patent Document 2 discloses a structure that swirls the coolant in the reserve tank, thereby separating air mixed in the coolant by centrifugal force. Patent Document 3 discloses a structure in which a partition plate with a hole in the lower part is provided in the reserve tank, and the air mixed in the coolant is separated while the coolant is retained between the partition plates. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2022-53938 A [Patent Document 2] Patent Publication No. 2021-169815 [Patent Document 3] JP 2022-149429 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, all of these patent documents are directed to separating air that has been mixed into the cooling liquid.

[0007] The inventors of the present invention have considered the fact that, rather than separating the air mixed in the coolant, preventing air from mixing in the coolant in the first place is more effective in suppressing deterioration of cooling efficiency.

[0008] FIG. 6 is a cross-sectional view of the periphery of the reserve tank a for explaining a situation in which air (air bubbles) c gets mixed into the coolant b in the reserve tank a. An inlet e made of a straight pipe is provided at the bottom of the side wall d of the reserve tank a, and an outlet g is provided at the bottom plate f of the reserve tank a. The coolant b that flows into the reserve tank a from the coolant circulation circuit (not shown) through the inlet e collides with the side wall h of the reserve tank a (the side wall opposite to the side wall d on which the inlet e is provided) and the flow line becomes upward, causing the liquid level of the coolant b to fluctuate (wave). The higher the flow rate of the coolant b flowing into the reserve tank a, the larger the fluctuation in the liquid level becomes. As the liquid level of the coolant b fluctuates in this way, the air i present in the upper layer of the reserve tank a is caught in the coolant b, and the air c gets mixed into the coolant b. If the air c flows out of the outlet g into the coolant circulation circuit and circulates through the coolant circulation circuit, it will cause a deterioration in cooling efficiency. Therefore, in order to suppress the deterioration of the cooling efficiency, it is effective to prevent the air c from mixing with the coolant b in the reserve tank a.

[0009] The present invention has been made in consideration of the above-mentioned points, and its object is to provide a structure for the inlet portion of a reserve tank that can prevent air from being mixed into the coolant. [Means for solving the problem]

[0010] The solution of the present invention for achieving the above object is based on the structure of an inlet of a reserve tank provided in a coolant circulation circuit, and is characterized in that, when the side closer to the reserve tank body in the flow direction of the coolant in the inlet is defined as one end side, and the side farther from the reserve tank body is defined as the other end side, the flow path area of ​​the one end side of the inlet part is larger than the flow path area of ​​the other end side.

[0011] According to this specification, when the coolant flows into the reserve tank (reserve tank body) from the coolant circulation circuit through the inflow section, the flow area of ​​one end side (the side closer to the reserve tank body in the flow direction of the coolant) is larger than the flow area of ​​the other end side (the side farther from the reserve tank body in the flow direction of the coolant) in the inflow section, so that the flow rate of the coolant can be reduced while suppressing a decrease in the flow rate at the inflow section (the amount of coolant flowing into the reserve tank body per unit time). Therefore, the liquid level of the coolant in the reserve tank body is suppressed from fluctuating due to the coolant flowing into the reserve tank body. Therefore, it is suppressed that the air present in the upper layer part in the reserve tank body is caught in the coolant and mixed into the coolant. As a result, the amount of air flowing out into the coolant circulation circuit can be significantly reduced, and deterioration of cooling efficiency can be suppressed.

[0012] More specifically, the flow passage shape inside the inlet portion is a tapered shape having a predetermined angle such that the flow passage area gradually increases from the other end side toward the one end side.

[0013] This makes it possible to suppress a rapid change in the flow rate of the cooling liquid flowing inside the inlet. By appropriately specifying the predetermined angle of the tapered shape, separation of the cooling liquid on the inner surface of the inlet can be suppressed, and the flow rate of the cooling liquid flowing inside the inlet can be reduced (the occurrence of dead water areas due to separation of the cooling liquid can be suppressed, and therefore the flow rate of the cooling liquid can be reduced). This also makes it possible to suppress the mixing of air into the cooling liquid inside the reserve tank body, as described above, and thus to suppress deterioration of the cooling efficiency.

[0014] Also, a guide vane may be provided inside the inlet portion to divide the flow path of the cooling liquid flowing inside the inlet portion into a plurality of paths.

[0015] According to this, the direction of the flow line of the coolant can be changed by the inner surface of the inlet (e.g., a tapered surface) or the surface of the guide vane, and the angle between the direction of the flow line of the coolant and the inner surface of the inlet or the surface of the guide vane can be made small while increasing the inclination angle of the flow path shape (the expansion rate of the cross-sectional area inside the inlet). Therefore, it is possible to shorten the length of the inlet required to reduce the flow rate of the coolant flowing into the reserve tank body to a predetermined flow rate (a flow rate that can prevent air from being mixed into the coolant in the reserve tank body) while suppressing separation of the coolant. Therefore, it is possible to reduce the size of the inlet while suppressing air from being mixed into the coolant in the reserve tank body.

[0016] Furthermore, a pressure loss member may be provided inside the inlet portion to impart a pressure loss to the cooling liquid flowing inside the inlet portion.

[0017] In this case, the flow rate of the coolant can be reduced by applying a pressure loss to the coolant flowing inside the inlet. This makes it possible to suppress separation of the coolant on the inner surface of the inlet, and to increase the inclination angle of the flow path shape. This makes it possible to shorten the length of the inlet required to reduce the flow rate of the coolant flowing into the reserve tank body to a predetermined flow rate while suppressing separation of the coolant. This also makes it possible to reduce the size of the inlet while suppressing air from being mixed into the coolant inside the reserve tank body.

[0018] In addition, one end of the inflow portion may be open in a direction intersecting the side wall of the reserve tank body, and the other end of the inflow portion may be open in a direction along the extension direction of the side wall of the reserve tank body.

[0019] According to this, the flow rate of the coolant flowing into the inlet from the other end side decreases as it flows in the direction along the extension direction of the side wall of the reserve tank body. In other words, it is possible to shorten the length of the inlet in the direction intersecting the side wall of the reserve tank body, compared to when the flow rate decreases as it flows in the direction intersecting the side wall of the reserve tank body. This also makes it possible to reduce the size of the inlet while preventing air from being mixed into the coolant inside the reserve tank body. Effect of the Invention

[0020] In the present invention, the flow passage area of ​​the inflow section of the reserve tank is larger at one end, which is closer to the reserve tank body, than at the other end, which is farther from the reserve tank body. This makes it possible to reduce the flow rate of the coolant while preventing the flow rate at the inflow section from decreasing, and to prevent air in the upper layer of the reserve tank body from being mixed into the coolant. As a result, the amount of air flowing out into the coolant circulation circuit can be significantly reduced, and deterioration of cooling efficiency can be suppressed. [Brief description of the drawings]

[0021] [Figure 1] 1 is a diagram showing a schematic configuration of a coolant circulation circuit provided with a reserve tank according to an embodiment; [Diagram 2] FIG. 2 is a cross-sectional view of the reserve tank and its periphery according to the embodiment. [Diagram 3] 3 is an enlarged cross-sectional view of an inlet portion of the reserve tank according to the embodiment; FIG. [Figure 4] 4A is a cross-sectional view showing an enlarged view of the inlet of a reserve tank according to a first modified example, FIG. 4B is a cross-sectional view in a direction perpendicular to the flow line when the flow velocity reduction section of the inlet is shaped like a truncated cone, and FIG. 4C is a cross-sectional view in a direction perpendicular to the flow line when the flow velocity reduction section of the inlet is shaped like a truncated pyramid. [Diagram 5] Figure 5(a) is a side view showing the inlet portion of the reserve tank for the second modified example, Figure 5(b) is an oblique view showing the inlet portion of the reserve tank for the third modified example, and Figure 5(c) is an oblique view showing the inlet portion of the reserve tank for the fourth modified example. [Figure 6] 1 is a cross-sectional view of the vicinity of a reserve tank for explaining a state in which air gets mixed into the coolant in the reserve tank in the conventional technology. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, the present invention is applied to a structure of an inlet of a reserve tank provided in a coolant circulation circuit in a battery cooling system of an electric vehicle. The coolant circulation circuit to which the present invention can be applied is not limited to the battery cooling system of an electric vehicle, but may be various cooling systems such as an inverter cooling system, an electric motor cooling system, and an engine cooling system in an engine-equipped vehicle.

[0023] -Outline of the coolant circulation circuit- Fig. 1 is a diagram showing a schematic configuration of a coolant circulation circuit 1 provided with a reserve tank 5 according to this embodiment. As shown in Fig. 1, the coolant circulation circuit 1 includes a pump 2, a heat exchanger 3, a battery (e.g., a coolant flow path provided inside the battery) 4, which is a device to be cooled, and the reserve tank 5, which are connected by piping 6 so as to enable circulation of the coolant.

[0024] The pump 2 is, for example, an electric pump, and circulates the coolant through the coolant circulation circuit 1 when it is operated.

[0025] The heat exchanger 3 exchanges heat between the coolant circulating in the coolant circulation circuit 1 and the outside air, and releases the heat of the coolant to the outside air, thereby cooling the coolant. Note that the medium that exchanges heat with the coolant is not limited to the outside air.

[0026] The battery 4 stores electric power to supply power to the driving motor, which is the driving force source for the electric vehicle, and other electric devices. The battery 4 generates heat when it is charged and discharged. In recent electric vehicles, the energy density of the battery 4 tends to increase in order to improve the driving performance of the vehicle and extend the driving range. Therefore, efficient cooling of the battery 4 is required. For this reason, it is necessary to reduce the amount of air in the coolant circulation circuit 1 to suppress deterioration of cooling efficiency.

[0027] The reserve tank 5 includes a reserve tank body 51 made of a substantially cylindrical container for storing the coolant, and the reserve tank body 51 is connected to a pipe (a pipe extending from the battery 4) 6 via an inlet portion 52 and to a pipe (a pipe extending to the suction side of the pump 2) 6 via an outlet portion 53. The reserve tank 5 also has a function of absorbing a change in volume caused by thermal expansion of the coolant. The reserve tank 5 is also used to replenish the coolant circulation circuit 1 with the coolant.

[0028] -Reserve tank configuration- Next, the configuration of the reserve tank 5 will be described. Fig. 2 is a cross-sectional view of the reserve tank 5 and its surroundings according to this embodiment. As shown in Fig. 2, the reserve tank 5 includes a reserve tank body 51, and an inlet portion 52 and an outlet portion 53 that are integrally connected to the reserve tank body 51.

[0029] The reserve tank body 51 is a generally cylindrical container, and includes a side wall 51a, a top plate 51b, and a bottom plate 51c. A predetermined amount of coolant 7 is stored inside the reserve tank body 51. When the amount of coolant 7 stored inside the reserve tank body 51 decreases to a predetermined amount (when the liquid level of the coolant 7 drops to a predetermined level), the coolant 7 is replenished from the top plate 51b side of the reserve tank body 51 (the configuration for replenishing is well known and is therefore not shown). The reserve tank body 51 is not limited to a generally cylindrical container, and may be a rectangular tubular container.

[0030] An inflow portion 52 is integrally connected to a lower portion of one side wall (the side wall located on the left side in FIG. 2) 51a of the reserve tank body 51. An outflow portion 53 is integrally connected to a bottom plate 51c of the reserve tank body 51 at a position near a side wall (the side wall facing the side wall 51a: the side wall located on the right side in FIG. 2) 51a' opposite to the side wall 51a to which the inflow portion 52 is connected.

[0031] (Structure of the inlet section) Next, the structure of the inlet section 52, which is a feature of this embodiment, will be described. Fig. 3 is an enlarged cross-sectional view of the inlet section 52. As shown in Fig. 3, the inlet section 52 has a straight pipe section 52a and a flow velocity reduction section 52b. The straight pipe section 52a is a section connected to the pipe 6 of the coolant circulation circuit 1, and the flow velocity reduction section 52b is a section connected to the side wall 51a of the reserve tank main body 51.

[0032] The straight pipe section 52a is formed of a straight pipe whose inner diameter is uniform over the entire length. The outer diameter of the straight pipe section 52a is approximately equal to the inner diameter of the pipe 6, and as shown in FIG. 2, the straight pipe section 52a is inserted into the pipe 6 to connect the pipe 6 to the inlet section 52. Conversely, the pipe 6 may be inserted into the straight pipe section 52a to connect the pipe 6 to the inlet section 52. In this embodiment, the inner and outer diameters of the straight pipe section 52a are approximately equal to the inner and outer diameters of the outlet section 53, which is made of a straight pipe.

[0033] When the side of flow velocity reduction section 52b closer to reserve tank body 51 (the side connected to reserve tank body 51) is defined as one end, and the side farther from reserve tank body 51 (the side connected to straight pipe section 52a) is defined as the other end, the flow path area of ​​one end is larger than the flow path area of ​​the other end. More specifically, the flow path shape inside flow velocity reduction section 52b is a tapered shape in which the flow path area gradually increases from the other end toward the one end.

[0034] In this way, since the flow path area on one end side of flow velocity reduction section 52b is larger than the flow path area on the other end side, the flow velocity of the cooling liquid 7 (cooling liquid 7 with flow velocity V1 in FIG. 3) that has flowed from pipe 6 into inlet section 52 is reduced (flow velocity V2 in FIG. 3 ( <V1)となる)ようになっている。

[0035] More specifically, the inclination angle (opening angle) θ of the tapered shape of the flow passage shape inside the flow rate reduction section 52b is set to less than 5°. This is to suppress separation of the coolant 7 on the inner surface of the inlet section 52, which may occur if the inclination angle θ of the tapered shape is too large. In other words, if separation of the coolant 7 occurs on the inner surface of the inlet section 52, this may cause a dead water area, making it impossible to reduce the flow rate of the coolant 7. In view of this, the inclination angle of the tapered shape is specified as described above to suppress separation of the coolant 7 on the inner surface of the inlet section 52 and suppress the generation of the dead water area, thereby making it possible to reduce the flow rate of the coolant 7.

[0036] Since the flow velocity reduction section 52b is configured in this manner, if the cross-sectional area of ​​the other end side (the end side upstream in the flow direction of the coolant 7) of the flow velocity reduction section 52b is A1 and the cross-sectional area of ​​one end side (the end side downstream in the flow direction of the coolant 7) is A2, in order to reduce the flow velocity of the coolant 7 to a predetermined flow velocity while keeping the inclination angle θ of the tapered shape as described above, the larger the ratio C=A2 / A1, the longer the length dimension of the flow velocity reduction section 52b needs to be.

[0037] - Coolant inflow status - Next, a description will be given of the flow of the coolant 7 into the reserve tank body 51 by providing the inlet portion 52 configured as described above. The dashed arrows in Fig. 2 indicate the flow of the coolant 7 flowing into the reserve tank body 51 and the flow of the coolant 7 flowing out from the reserve tank body 51 to the coolant circulation circuit 1.

[0038] The coolant 7 that has flowed into the inlet section 52 from the pipe 6 of the coolant circulation circuit 1 passes through the straight pipe section 52a and then flows through the flow rate reduction section 52b. The internal flow path shape of this flow rate reduction section 52b is a tapered shape in which the flow path area gradually increases in the flow direction of the coolant 7, so that the flow rate of the coolant 7 at the inlet section 52 (the amount of the coolant 7 that flows into the reserve tank main body 51 per unit time) is prevented from decreasing, while the flow rate of the coolant 7 decreases. Therefore, the flow rate of the coolant 7 flowing into the reserve tank main body 51 also decreases.

[0039] In the conventional technology, the coolant (which has a relatively high flow rate) that flows into the reserve tank body collides with the side wall (the side wall opposite the side wall where the inlet is located) of the reserve tank body, causing the flow line to move upward, and the coolant level to fluctuate, which makes it highly likely that the air in the upper layer of the reserve tank body will be entrained in the coolant. This causes the air to flow out of the outlet into the coolant circulation circuit, resulting in a deterioration in cooling efficiency.

[0040] In contrast, in this embodiment, the flow rate of the coolant 7 flowing into the reserve tank body 51 is reduced, so fluctuations in the liquid level of the coolant 7 are suppressed, and this makes it possible to prevent the air A present in the upper layer portion of the reserve tank body 51 from being mixed into the coolant 7. As a result, the amount of air flowing out into the coolant circulation circuit 1 can be significantly reduced, making it possible to suppress deterioration of the cooling efficiency.

[0041] -Effects of the embodiment- As described above, in this embodiment, the flow path area of ​​the inflow section 52 of the reserve tank 5 at one end side, which is closer to the reserve tank body 51, is made larger than the flow path area of ​​the other end side, which is farther from the reserve tank body 51. Therefore, the flow velocity of the coolant 7 can be reduced while suppressing the flow rate at the inflow section 52 from decreasing, and the air A present in the upper layer portion of the reserve tank body 51 can be suppressed from being mixed into the coolant 7. As a result, the amount of air flowing out to the coolant circulation circuit 1 can be significantly reduced, and the deterioration of the cooling efficiency can be suppressed. And, since the deterioration of the cooling efficiency can be suppressed in this way, the battery 4 can be efficiently cooled, which contributes to improving the energy consumption rate (electricity cost).

[0042] The inventors of the present invention calculated the amount of air flowing out from the outflow portion 53 (the amount of air flowing out into the coolant circulation circuit 1) by numerical analysis. Specifically, the ratio of the cross-sectional area of ​​the downstream end of the inflow portion to the upstream end was set to 1 for the prior art, and the ratio of the cross-sectional area of ​​the downstream end of the inflow portion 52 to the upstream end was set to 2 for the present invention. As a result, it was confirmed that the amount of air flowing out from the outflow portion 53 was reduced by approximately 50% in the reserve tank 5 of the present invention compared to the reserve tank of the prior art. It was thus confirmed that the deterioration of cooling efficiency could be suppressed.

[0043] -First modified example- Next, a first modified example will be described. In this modified example, the configuration of the flow velocity reduction section 52b, particularly the internal configuration of the flow velocity reduction section 52b, is different from that of the embodiment described above. Since the other configurations are the same as those of the embodiment described above, only the differences from the embodiment described above will be described here.

[0044] Figure 4 shows the inlet section 52A of the reserve tank 5 in this modified example, where Figure 4(a) is an enlarged cross-sectional view of the inlet section 52A, and Figure 4(b) is a cross-sectional view in a direction perpendicular to the flow line when the flow velocity reduction section 52b of the inlet section 52A is shaped like a truncated cone.

[0045] As shown in these figures, the flow velocity reduction section 52b according to this modification is provided with a plurality of guide vanes 52c, 52c, ... that divide the flow path of the cooling liquid 7 flowing thereinto into a plurality of paths. As shown in FIG. 4(b), each guide vane 52c extends in the horizontal direction and both ends are connected to the inner surface of the flow velocity reduction section 52b. As a result, the inside of the flow velocity reduction section 52b is formed with a plurality of flow paths that are independent of each other in the vertical direction. In addition, the inclination angle (inclination angle with respect to the horizontal direction) of each guide vane 52c, 52c, ... is larger for the guide vane 52c located on the outer side (located on the outer side in the vertical direction). More specifically, the inclination angle of each guide vane 52c, 52c, ... is arranged so that the angle formed with the adjacent wall surface (the inner surface of the flow velocity reduction section 52b or the wall surface of the adjacent guide vane 52c) is less than a predetermined angle (for example, 5°).

[0046] In this way, when the guide vanes 52c, 52c, ... are provided inside the flow velocity reduction portion 52b, the direction of the flow line of the coolant 7 can be changed (slightly changed outward) by the inner surface (e.g., tapered surface) of the flow velocity reduction portion 52b or the surface of the guide vane 52c, and it is possible to increase the inclination angle of the flow path shape (the expansion rate of the cross-sectional area inside the flow velocity reduction portion 52b) while reducing the angle between the direction of the flow line of the coolant 7 and the inner surface of the flow velocity reduction portion 52b or the surface of the guide vane 52c. Therefore, it is possible to shorten the length of the inflow portion 52A required to reduce the flow rate of the coolant 7 flowing into the reserve tank main body 51 to a predetermined flow rate (a flow rate that can prevent air from being mixed into the coolant 7 in the reserve tank main body 51) while suppressing separation of the coolant 7. Therefore, it is possible to reduce the size of the inflow portion 52A while suppressing air from being mixed into the coolant 7 in the reserve tank main body 51.

[0047] FIG. 4(c) is a cross-sectional view in a direction perpendicular to the flow line when the flow velocity reduction section 52b of the inlet section 52A is formed in a quadrangular pyramid shape. In the example shown in FIG. 4(c), a plurality of guide vanes 52c, 52c, ... are provided inside the flow velocity reduction section 52b. In this configuration, as in the above, it is possible to shorten the length of the inlet section 52A required to reduce the flow velocity of the coolant 7 flowing into the reserve tank main body 51 to a predetermined flow velocity while suppressing the separation of the coolant 7. Therefore, it is possible to reduce the size of the inlet section 52A while suppressing the mixing of air into the coolant 7 in the reserve tank main body 51.

[0048] -Second modified example- Next, a second modified example will be described. This modified example also differs from the embodiment described above in the configuration of the flow velocity reduction section 52b. Other configurations are similar to those of the embodiment described above, so only the differences from the embodiment described above will be described here.

[0049] Fig. 5(a) is a side view showing inlet section 52B of reserve tank 5 according to this modified example. As shown in Fig. 5(a), flow velocity reduction section 52b of inlet section 52B according to this modified example has a configuration in which enlarged diameter section 52d, cylindrical section 52e, and reduced diameter section 52f are integrally arranged along the flow direction of coolant 7.

[0050] The flow passage shape inside the expanded diameter portion 52d is a tapered shape in which the flow passage area gradually increases from the other end side toward the one end side. Therefore, the upstream side of the expanded diameter portion 52d in the coolant flow direction (the left side in FIG. 5(a)) corresponds to the "other end side that is farther from the reserve tank body" in the present invention, and the downstream side of the expanded diameter portion 52d in the coolant flow direction (the right side in FIG. 5(a)) corresponds to the "one end side that is closer to the reserve tank body" in the present invention.

[0051] In addition, a pressure loss member 52g (shown by a broken line in FIG. 5(a)) made of a mesh material, a porous body, or the like is accommodated inside the cylindrical portion 52e. The shape of this pressure loss member 52g is a columnar shape that is approximately the same as the shape of the inside of the cylindrical portion 52e. This causes a pressure loss to be added to the coolant 7 when the coolant 7 passes through the inside of the cylindrical portion 52e. Therefore, the flow rate of the coolant 7 that flows into the inflow portion 52B is reduced in the enlarged diameter portion 52d, and separation is therefore unlikely to occur. For this reason, the inclination angle can be increased as the shape of the flow passage inside the enlarged diameter portion 52d, and separation is unlikely to occur even when this inclination angle is set to 5° or more. Therefore, it is possible to shorten the length of the inflow portion 52B required to reduce the flow rate of the coolant 7 flowing into the reserve tank body 51 to a predetermined flow rate while suppressing separation of the coolant 7. This also makes it possible to prevent air from being mixed into the coolant 7 inside the reserve tank body 51, while also making it possible to reduce the size of the inflow portion 52B.

[0052] The reason for providing reduced diameter section 52f downstream of cylindrical section 52e is to straighten the flow of coolant 7 while allowing it to flow into reserve tank body 51, taking into consideration the possibility that the velocity distribution of coolant 7 may be disturbed as it passes through pressure loss member 52g when it flows through cylindrical section 52e.

[0053] -Third variant- Next, a third modified example will be described. This modified example differs from the above-described embodiment in the overall configuration of the inlet portion 52. Other configurations are similar to those of the above-described embodiment, so here too, only the differences from the above-described embodiment will be described.

[0054] Fig. 5(b) is a perspective view showing an inlet section 52C of the reserve tank 5 according to this modification. As shown in Fig. 5(b), the inlet section 52C according to this modification has an upstream straight pipe section 52h, a cylindrical section 52i, and a downstream straight pipe section 52j that are integrally arranged.

[0055] The upstream straight pipe section 52h extends in the vertical direction (the extension direction of the side wall 51a of the reserve tank body 51). The upstream end of the upstream straight pipe section 52h in the flow direction of the coolant 7 opens downward, and this open portion is connected to the pipe 6.

[0056] The cylindrical portion 52i is formed in a cylindrical shape with the horizontal direction (the direction intersecting with the side wall 51a of the reserve tank main body 51) as the direction of the center line. The upstream straight pipe portion 52h is connected to the cylindrical portion 52i from the lower side in the tangential direction of the outer circumferential surface of the cylindrical portion 52i. Therefore, when the cooling liquid 7 flows from the upstream straight pipe portion 52h into the cylindrical portion 52i, the cooling liquid 7 flows inside the cylindrical portion 52i as a swirling flow along the inner circumferential surface of the cylindrical portion 52i. The internal area of ​​the cylindrical portion 52i (the area in the direction perpendicular to the direction of the flow line of the swirling flow) is larger than the flow passage area of ​​the upstream straight pipe portion 52h, so that the flow velocity of the cooling liquid 7 is reduced. Therefore, the portion of cylindrical portion 52i to which upstream straight pipe portion 52h is connected corresponds to the "other end side, which is the side farther from the reserve tank body" in this invention, and the downstream portion in the flow direction of coolant 7 in the internal space of cylindrical portion 52i corresponds to the "one end side, which is the side closer to the reserve tank body" in this invention.

[0057] Further, downstream straight pipe section 52j is connected to the center of the side wall of cylindrical section 52i facing reserve tank body 51, and its opening direction is horizontal (direction intersecting side wall 51a of reserve tank body 51), and this opening part is connected to side wall 51a of reserve tank body 51. Further, the inner diameter dimension of downstream straight pipe section 52j is set to be larger than the inner diameter dimension of upstream straight pipe section 52h, so that the flow velocity of coolant 7 does not become too high when the coolant 7 flows inside downstream straight pipe section 52j.

[0058] In this modification, the flow rate of the coolant 7 that has flowed into the inlet portion 52C decreases as it flows in a direction along the extension direction of the side wall 51a of the reserve tank body 51. In other words, it is possible to shorten the length of the inlet portion 52C in the direction intersecting the side wall 51a of the reserve tank body 51, compared to a case in which the flow rate decreases as it flows in a direction intersecting the side wall 51a of the reserve tank body 51. This also makes it possible to reduce the size of the inlet portion 52C while suppressing air from being mixed into the coolant 7 in the reserve tank body 51.

[0059] -Fourth Variation- Next, the fourth modified example will be described. This modified example differs from the third modified example in the configuration of the upstream straight pipe section 52h. The other configurations are the same as those of the third modified example, so here, only the differences from the third modified example will be described.

[0060] Fig. 5(c) is a perspective view showing an inlet section 52D of the reserve tank 5 according to this modification. As shown in Fig. 5(c), the inlet section 52D according to this modification also has an upstream straight pipe section 52h, a cylindrical section 52i, and a downstream straight pipe section 52j that are integrally arranged. The configurations of the cylindrical section 52i and the downstream straight pipe section 52j are the same as those of the third modification described above.

[0061] The upstream straight pipe section 52h extends in the vertical direction (the extension direction of the side wall 51a of the reserve tank body 51). The upstream end of the upstream straight pipe section 52h in the flow direction of the coolant 7 opens upward, and this open portion is connected to the piping 6. The upstream straight pipe section 52h is connected to the cylindrical section 52i from above in the tangential direction of the outer circumferential surface of the cylindrical section 52i.

[0062] Even in this modification, the flow rate of the coolant 7 that has flowed into the inlet portion 52D decreases as it flows in a direction along the extension direction of the side wall 51a of the reserve tank body 51. In other words, it is possible to shorten the length of the inlet portion 52D in the direction intersecting the side wall 51a of the reserve tank body 51, compared to the case where the flow rate decreases as it flows in a direction intersecting the side wall 51a of the reserve tank body 51. This also makes it possible to reduce the size of the inlet portion 52C while suppressing air from being mixed into the coolant 7 in the reserve tank body 51.

[0063] Furthermore, in the configurations of the third and fourth modified examples described above, the opening direction of the upstream straight pipe section 52h can be set arbitrarily, which allows for a high degree of freedom in mounting the reserve tank 5 on the vehicle.

[0064] -Other embodiments- The present invention is not limited to the above-described embodiment and each of the modifications, and all modifications and applications encompassed within the scope of the claims and equivalents thereto are possible.

[0065] For example, in the embodiment and each of the modified examples, the reserve tank body 51, the inlet portion 52 (52A, 52B, 52C, 52D), and the outlet portion 53 are integrally molded to form the reserve tank 5. The present invention is not limited to this, and the reserve tank body 51, the inlet portion 52 (52A, 52B, 52C, 52D), and the outlet portion 53 may be molded separately, and the reserve tank 5 may be formed by assembling them integrally.

[0066] In the embodiment and the first modified example, the shape of the flow velocity reduction portion 52b is a tapered shape in which the flow area gradually increases from the other end side (the side farther from the reserve tank body 51 in the flow direction of the coolant 7) to the one end side (the side closer to the reserve tank body 51 in the flow direction of the coolant 7) around the entire periphery. The present invention is not limited to this, and a part of the periphery of the flow velocity reduction portion 52b may be inclined from the other end side to the one end side, so that the flow area gradually increases (for example, only the upper part of the flow velocity reduction portion 52b may be shaped to expand upward). In addition, the flow path shape inside the inflow portion 52 does not necessarily have to be a tapered shape as long as the flow path area on the one end side is larger than the flow path area on the other end side. For example, the inner surface of the inflow portion 52 may be shaped in a stepped shape, so that the flow path area on the one end side is larger than the flow path area on the other end side. [Industrial Applicability]

[0067] The present invention is applicable to the structure of an inlet portion of a reserve tank provided in a coolant circulation circuit in a battery cooling system of an electric vehicle. [Explanation of symbols]

[0068] 1 Coolant circulation circuit 5 Reserve Tank 51 Reserve tank body 52 Inlet 52b Flow velocity reduction section 52c Guide vane 52g Pressure loss material 7 Coolant

Claims

1. A structure of an inlet portion of a reserve tank provided in a coolant circulation circuit, comprising: A structure of an inlet of a reserve tank, characterized in that when the side closer to the reserve tank body in the flow direction of the coolant in the inlet is defined as one end side, and the side farther from the reserve tank body is defined as the other end side, the flow path area of ​​the one end side of the inlet portion is larger than the flow path area of ​​the other end side.

2. In the structure of the inlet portion of the reserve tank according to claim 1, A structure of an inlet portion of a reserve tank, characterized in that the flow path shape inside the inlet portion is a tapered shape having a predetermined angle such that the flow path area gradually increases from the other end side to the one end side.

3. In the structure of the inlet portion of the reserve tank according to claim 1 or 2, A structure of an inlet portion of a reserve tank, characterized in that a guide vane is provided inside the inlet portion to divide the flow path of the cooling liquid flowing inside the inlet portion into multiple parts.

4. In the structure of the inlet portion of the reserve tank according to claim 1 or 2, 2. The structure of an inlet portion of a reserve tank, wherein a pressure loss member is provided inside the inlet portion to add pressure loss to the cooling liquid flowing inside the inlet portion.

5. In the structure of the inlet portion of the reserve tank according to claim 1 or 2, A structure of an inlet portion of a reserve tank, characterized in that one end of the inlet portion is open in a direction intersecting the side wall of the reserve tank body, and the other end of the inlet portion is open in a direction along the extension direction of the side wall of the reserve tank body.

Images