Coolant tank

Abstract

To provide a coolant tank capable of reducing entrapment of air on a liquid level even when a flow rate of a flowing coolant becomes high.SOLUTION: A reserve tank 20 is provided in a cooling circuit 1 in which a coolant circulates to cool a heat generating apparatus 13 mounted to a vehicle. The reserve tank 20 includes: a tank body 21 that stores the coolant; an inflow port 22 that is provided in a lower part of the tank body 21 and to which the coolant flows in from the cooling circuit 1; and an outflow port 23 from which the coolant in the tank body 21 flows out to the cooling circuit 1. The tank body 21 includes: a first wall part 51 that disperses a flow of the coolant flowing into the tank body 21; and a second wall part 52 that blocks the flow of the coolant flowing upwards along the first wall part 51.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a coolant tank provided in a cooling circuit for cooling a heat-generating device. [Background technology]

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development into electrification technologies is being conducted in order to reduce CO2 emissions and improve energy efficiency in vehicles. As electrification increases, devices such as power conversion devices installed in vehicles generate a large amount of heat, so these devices may be cooled using coolants, for example.

[0003] For example, Patent Document 1 describes an equipment cooling system for a vehicle equipped with a cooling circuit in which coolant circulates to cool heat-generating equipment. The cooling circuit described in Patent Document 1 is equipped with a reserve tank having a coolant storage section, and the reserve tank has a coolant inlet in a lower region of the coolant storage section. The reserve tank absorbs volume changes due to thermal expansion of the coolant and discharges air bubbles generated in the cooling circuit to the outside. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7146865 Summary of the Invention [Problem to be solved by the invention]

[0005] In order to improve the cooling performance of heat-generating equipment, if the pump installed in the cooling circuit is made high-powered and the flow rate of the coolant flowing through the cooling circuit is increased, in a reserve tank in which the coolant inlet is installed in the lower region of the coolant storage section, as in Patent Document 1, the flow rate at the liquid surface in the reserve tank will increase, causing the liquid surface to become unstable and there is a risk of air being drawn into the coolant.

[0006] The present invention provides a coolant tank that can reduce air entrainment on the liquid surface even when the flow rate of the coolant is high. [Means for solving the problem]

[0007] The present invention provides A coolant tank provided in a cooling circuit through which a coolant circulates to cool heat-generating equipment mounted on a vehicle, a tank body that stores the cooling liquid; an inlet formed in a lower portion of the tank body, through which the coolant flows from the cooling circuit; an outlet through which the cooling liquid in the tank body flows into the cooling circuit, The tank body is a first wall portion that disperses the flow of the cooling liquid that has flowed into the tank body; and a second wall portion that blocks the flow of the cooling liquid upward along the first wall portion. [Effects of the Invention]

[0008] According to the present invention, the flow of cooling liquid toward the liquid surface is dispersed by the first wall portion and the second wall portion provided on the tank body, so that even if the flow rate of cooling liquid flowing through the cooling circuit is high, the flow rate of the cooling liquid at the liquid surface can be reduced, and air entrainment caused by liquid surface turbulence can be reduced. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a circuit diagram of a cooling circuit 1 provided with a reserve tank 20 that is an embodiment of a coolant tank of the present invention. [Figure 2] FIG. 2 is a side view of the reserve tank 20 as seen from the rear. [Figure 3] 2 is an enlarged cross-sectional view of the reserve tank 20 showing the structure in the vicinity of the first wall portion 51 and the second wall portion 52. FIG. [Figure 4] 10 shows the state of the coolant level L when the reserve tank 20 is tilted at a predetermined angle while the vehicle is running. [Figure 5] FIG. 2 is a view of the reserve tank 20 as seen from the right side. [Figure 6] 6 is a perspective view of a cross section taken along line AA in FIG. 5, viewed from below on the left side. [Figure 7] 2 shows a reserve tank 200 of a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0010] An embodiment of a coolant tank of the present invention will be described below with reference to the accompanying drawings. For convenience, directions will be identified by the orientation of the coolant tank when mounted on a vehicle, with the front of the vehicle indicated as Fr, the rear as Rr, the left as L, the right as R, the top as U, and the bottom as D. However, the orientation of the coolant tank when mounted on a vehicle can vary, and is not limited to the orientation shown in the drawings.

[0011] FIG. 1 is a circuit diagram of a cooling circuit 1 that cools a heat-generating device 13 mounted on a vehicle. The vehicle may be, for example, a hybrid vehicle, an electric vehicle, a fuel cell vehicle, or a gasoline engine vehicle. A coolant circulates through the cooling circuit 1 to cool the heat-generating device 13. The heat-generating device 13 may be, for example, a power conversion device (PCU (Power Control Unit)) that controls a drive motor of the vehicle and generates a large amount of heat. However, the heat-generating device 13 is not limited to a power conversion device and may be, for example, an engine, a high-voltage battery, a charger, or the like. The coolant may be a liquid that has high thermal conductivity and is resistant to freezing, and is mainly composed of ethylene glycol or the like.

[0012] The cooling circuit 1 includes a pump 11 that circulates the coolant, a radiator 12 that exchanges heat between the coolant and the outside air, a heat-generating device 13, and a reserve tank 20 that stores the coolant to be replenished in the cooling circuit 1. The pump 11, radiator 12, heat-generating device 13, and reserve tank 20 are arranged in this order from the discharge side of the pump 11 toward the suction side.

[0013] 2 is a side view of the reserve tank 20 as seen from the rear. The reserve tank 20 is an expansion tank that absorbs volume changes caused by thermal expansion of the coolant circulating in the cooling circuit 1 and separates air bubbles generated in the cooling circuit 1 from the coolant (gas-liquid separation).

[0014] The reserve tank 20 includes a tank body 21 that stores the coolant, an inlet 22 formed at the bottom of the tank body 21 through which the coolant flows in from the cooling circuit 1, an outlet 23 through which the coolant in the tank body 21 flows out into the cooling circuit 1, and a cap 24 that closes an inlet provided at the top of the tank body 21. The coolant can be refilled into the tank body 21 by removing the cap 24.

[0015] The tank body 21 has a cylindrical shape with a bottom that is long in the vertical direction. The tank body 21 includes a lower tank member 21A that forms the lower portion of the tank body 21, and an upper tank member 21B that forms the upper portion of the tank body 21. The lower tank member 21A and the upper tank member 21B are each molded from resin or the like using a mold. A flange portion 31 of the lower tank member 21A and a flange portion 41 of the upper tank member 21B are fixed by welding, for example. The fixing point between the lower tank member 21A and the upper tank member 21B is provided in approximately the center of the tank body 21 in the vertical direction, which prevents the molds used to mold the lower tank member 21A and the upper tank member 21B from becoming too large, thereby reducing the cost of the molds.

[0016] When a normal amount of coolant is stored in the tank body 21, the lower tank member 21A is filled with the coolant, and the coolant level L is located in the upper tank member 21B. More specifically, the coolant level L is located within a predetermined level range (the range between MAX and MIN in FIG. 2) in the upper tank member 21B.

[0017] The inlet 22 is formed in the lower part of the tank body 21 and is connected to a pipe (not shown) downstream of the heat-generating device 13. The inlet 22 is provided in the right corner of the bottom 32 of the lower tank member 21A and faces leftward and upward. The inlet 22 faces at an angle relative to the left wall portion (first wall portion 51 described later) of the side wall portion 33 of the lower tank member 21A.

[0018] The outlet 23 is formed in the lower part of the tank body 21 and is connected to a pipe (not shown) on the upstream side of the pump 11. The outlet 23 is provided in the right wall part of the side wall part 33 of the lower tank member 21A. The outlet 23 is located above the inlet 22. Furthermore, a partition part 25 is provided inside the tank body 21 between the inlet 22 and the outlet 23.

[0019] Recently, there has been a demand for a cooling circuit 1 that can accommodate a high flow rate of coolant in order to improve the cooling performance of heat-generating equipment 13. In a configuration in which inlet 22 of reserve tank 20 provided in cooling circuit 1 is formed in the lower part of tank body 21, if the flow rate of coolant flowing in from inlet 22 is high, the flow rate of the coolant at liquid level L in tank body 21 increases, causing the liquid level L to become unstable, and air may be entrained in the coolant (i.e., air bubbles may be mixed in the coolant).

[0020] Therefore, the reserve tank 20 of this embodiment has a structure that can disperse the flow of the coolant between the inlet 22 and the liquid level L, thereby reducing the flow velocity at the liquid level L. Specifically, the tank body 21 has a first wall portion 51 that disperses the flow of the coolant that has flowed into the tank body 21, and a second wall portion 52 that blocks the flow of the coolant upward along the first wall portion 51.

[0021] 3 is an enlarged cross-sectional view of the reserve tank 20, showing the structure near the first wall portion 51 and the second wall portion 52. The thick solid arrows in FIG. 3 indicate the flow of coolant that has flowed into the tank body 21 from the inlet 22. The first wall portion 51 extends in the vertical direction from the lower part of the tank body 21 to the second wall portion 52. Specifically, the first wall portion 51 corresponds to the left wall portion of the side wall portion 33 that constitutes the outer shape of the lower tank member 21A, and extends in the vertical direction from the bottom portion 32 of the lower tank member 21A to the flange portion 31.

[0022] The second wall portion 52 is provided above the first wall portion 51 and extends in a direction (substantially horizontal) perpendicular to the flow direction of the coolant flowing upward along the first wall portion 51. The second wall portion 52 is located below the liquid level L of the coolant. Specifically, the second wall portion 52 is provided on the left side of the upper tank member 21B and extends in a substantially horizontal direction from the flange portion 41 toward the inside (right side) of the upper tank member 21B. The inner end (right end) of the second wall portion 52 is connected to the side wall portion 42 that forms the outer shape of the upper tank member 21B. In other words, the second wall portion 52 is formed by recessing the left side of the side wall portion 42 of the upper tank member 21B from the flange portion 41 toward the inside of the upper tank member 21B.

[0023] The coolant flowing into the tank body 21 from the inlet 22 first hits the first wall 51 facing the inlet 22. Then, the coolant flowing upward along the first wall 51 hits the second wall 52. Because the first wall 51 and the second wall 52 are arranged opposite the flow of the coolant, even when the flow of the coolant flowing in from the inlet 22 is high, the flow of the coolant is sufficiently dispersed by the first wall 51 and the second wall 52 before reaching the liquid level L, reducing the flow velocity at the liquid level L. This reduces air entrainment at the liquid level L. Furthermore, because the flow dispersion at the first wall 51 and the second wall 52 reduces the flow velocity at the liquid level L, there is no need to increase the size of the tank body 21 in order to reduce the flow velocity at the liquid level L, and the reserve tank 20 can be made smaller.

[0024] The tank body 21 further has a third wall portion 53 extending downward from the second wall portion 52. The third wall portion 53 is provided on the inner end portion (right end portion) of the second wall portion 52. Specifically, the third wall portion 53 is provided on the upper tank member 21B, similar to the second wall portion 52, and is formed by the side wall portion 42 of the upper tank member 21B extending downward beyond the second wall portion 52. The lower end portion of the third wall portion 53 is located at approximately the same position as the flange portion 41 in the up-down direction. The third wall portion 53 also extends in the front-rear direction (see FIGS. 5 and 6).

[0025] Since the tank body 21 has the third wall portion 53, the coolant flowing upward along the first wall portion 51 can be made to hit the third wall portion 53 further, thereby further dispersing the flow of the coolant.

[0026] 4 shows the state of the coolant level L when the reserve tank 20 mounted on a vehicle is temporarily tilted at a predetermined angle (for example, 30 degrees). The second wall portion 52 and the third wall portion 53 are provided at the bottom of the upper tank member 21B, and are configured so that the coolant level L does not reach the second wall portion 52 and the third wall portion 53 even when the reserve tank 20 is tilted. This configuration makes it possible to prevent air from accumulating in the area surrounded by the second wall portion 52 and the third wall portion 53.

[0027] 5 is a view of the reserve tank 20 as seen from the right side, and FIG. 6 is a perspective view of a cross section taken along line AA in FIG. 5 as seen from below on the left side.

[0028] A slit 54 is provided in the third wall portion 53. The slit 54 is a cutout that opens downward and is formed in a part of the third wall portion 53. The provision of the slit 54 makes it possible to prevent air contained in the coolant that flows in from the inlet 22 (i.e., air bubbles that are generated when the coolant flows through the cooling circuit 1) from accumulating in the area surrounded by the second wall portion 52 and the third wall portion.

[0029] The slit 54 is provided offset from the inlet 22 in the front-rear direction in which the third wall portion 53 extends. This makes it easier for the coolant that flows from the inlet 22 along the first wall portion 51 to hit the second wall portion 52 and the third wall portion 53 before passing through the slit 54, thereby improving the flow dispersion effect at the second wall portion 52 and the third wall portion 53.

[0030] 7 shows a reserve tank 200 of a comparative example. The reserve tank 200 of the comparative example differs from the reserve tank 20 of the present embodiment in that the second wall portion 52 is not provided.

[0031] Similar to the inlet 22 of the reserve tank 20 of this embodiment, the inlet 22 of the reserve tank 200 is formed in the lower part of the tank body 21 and faces the first wall 51 of the tank body 21. The first wall 51 disperses the flow of the coolant that has flowed into the tank body 21. The coolant that has flowed into the tank body 21 from the inlet 22 flows upward along the first wall 51. However, since the reserve tank 200 of the comparative example does not have the second wall 52, the coolant flowing along the first wall 51 reaches the liquid level L before being sufficiently dispersed. Therefore, in the reserve tank 200 of the comparative example, when the flow rate of the coolant flowing in from the inlet 22 is high, the flow velocity of the coolant at the liquid level L increases, causing the liquid level L to become unstable, and air is likely to be entrained in the coolant.

[0032] Furthermore, the tank body 21 of the reserve tank 200 of the comparative example has a lower tank member 21A and an upper tank member 21B, and the liquid level L is located in the lower tank member 21A. If the second wall portion 52 extending substantially horizontally is provided on the lower tank member 21A of the reserve tank 200 of the comparative example, the second wall portion 52 would interfere with the removal of the lower tank member 21A from a mold. Therefore, the second wall portion 52 must be separately welded after the lower tank member 21A, which does not have the second wall portion 52, is molded using a mold. On the other hand, in this embodiment, the second wall portion 52 is formed by recessing the left portion of the side wall portion 42 of the upper tank member 21B. Therefore, the second wall portion 52 does not interfere with the removal of the upper tank member 21B from the mold, and the second wall portion 52 can be molded integrally with the upper tank member 21B using a mold.

[0033] Although one embodiment of the present invention has been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can conceive of various modifications or alterations within the scope of the claims, and it is understood that these also naturally fall within the technical scope of the present invention. Furthermore, the components of the above embodiment may be combined in any manner without departing from the spirit of the invention.

[0034] This specification describes at least the following: In parentheses, components corresponding to those in the above-described embodiments are shown as examples, but the present invention is not limited to these.

[0035] (1) A coolant tank (reserve tank 20) ​​provided in a cooling circuit (cooling circuit 1) through which a coolant circulates to cool a heat-generating device (heat-generating device 13) mounted on a vehicle, A tank body (tank body 21) that stores the cooling liquid; an inlet (inlet 22) formed in a lower portion of the tank body, through which the coolant flows from the cooling circuit; an outlet (outlet 23) through which the coolant in the tank body flows out into the cooling circuit, The tank body is a first wall portion (first wall portion 51) that disperses the flow of the cooling liquid that has flowed into the tank body; and a second wall portion (second wall portion 52) that blocks the flow of the cooling liquid upward along the first wall portion. Coolant tank.

[0036] According to (1), since the tank body has a first wall portion, the coolant flowing in from the inlet can hit the first wall portion and disperse the flow. Also, since the tank body has a second wall portion that blocks the upward flow of the coolant along the first wall portion, the coolant flowing upward (i.e., toward the liquid surface) can hit the second wall portion and further disperse the flow. Therefore, even if the flow rate of the coolant flowing through the cooling circuit is high, the flow velocity of the coolant at the liquid surface can be reduced, and air entrainment due to liquid surface turbulence can be reduced.

[0037] (2) The coolant tank according to (1), The tank body further has a third wall portion (third wall portion 53) extending downward from the second wall portion. Coolant tank.

[0038] According to (2), the coolant can be made to hit the third wall portion, thereby further dispersing the flow.

[0039] (3) The coolant tank according to (2), The third wall portion is provided with a slit (slit 54). Coolant tank.

[0040] According to (3), it is possible to prevent air contained in the coolant from accumulating in the area surrounded by the second wall portion and the third wall portion.

[0041] (4) A coolant tank according to (3), The third wall portion extends in a first direction perpendicular to the up-down direction, The slit is provided offset from the inlet in the first direction. Coolant tank.

[0042] According to (4), even when slits are provided, the flow dispersion effect in the second wall portion and the third wall portion can be improved.

[0043] (5) A coolant tank according to any one of (1) to (4), The tank body has a lower tank member (lower tank member 21A) that constitutes a lower portion of the tank body, and an upper tank member (upper tank member 21B) that constitutes an upper portion of the tank body, The second wall portion is formed by recessing a part of the side wall portion (side wall portion 42) of the upper tank member. Coolant tank.

[0044] According to (5), when the lower tank member and the upper tank member are molded using a mold, the second wall portion does not get in the way when the members are removed from the mold. [Explanation of symbols]

[0045] 1 Cooling circuit 13 Heat-generating equipment 20 Reserve tank (coolant tank) 21 Tank body 21A Lower tank member 21B Upper tank member 22 Inlet 23 Outlet 42 Side wall 51 1st wall 52 2nd wall section 53 Third wall 54 Slit

Claims

1. A coolant tank provided in a cooling circuit through which a coolant circulates to cool heat-generating equipment mounted on a vehicle, a tank body that stores the cooling liquid; an inlet formed in a lower portion of the tank body, through which the coolant flows from the cooling circuit; an outlet through which the cooling liquid in the tank body flows into the cooling circuit, The tank body is a first wall portion that disperses the flow of the cooling liquid that has flowed into the tank body; a second wall portion that blocks the flow of the cooling liquid upward along the first wall portion, Coolant tank.

2. 2. The coolant tank according to claim 1, The tank body further includes a third wall portion extending downward from the second wall portion. Coolant tank.

3. 3. The coolant tank according to claim 2, The third wall portion is provided with a slit. Coolant tank.

4. 4. The coolant tank according to claim 3, The third wall portion extends in a first direction perpendicular to the up-down direction, The slit is provided offset from the inlet in the first direction. Coolant tank.

5. 5. A coolant tank according to claim 1, The tank body has a lower tank member that constitutes a lower portion of the tank body and an upper tank member that constitutes an upper portion of the tank body, the second wall portion is formed by recessing a portion of the side wall portion of the upper tank member. Coolant tank.

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