Cooling liquid tank

Abstract

The invention provides a cooling liquid tank capable of reducing air entrainment at the liquid level even when the flow rate of flowing cooling liquid is high. A storage tank (20) is provided in a cooling circuit (1) for circulating a cooling liquid and cooling a heat-generating device (13) mounted on a vehicle. The storage tank (20) is provided with: a tank main body (21) for storing a cooling liquid; an inflow port (22) which is formed in the lower part of the tank main body (21) and into which a cooling liquid flows from the cooling circuit (1); and an outlet (23) through which the cooling liquid in the tank main body (21) flows out to the cooling circuit (1). The tank main body (21) has: a first wall section (51) for dispersing the flow of the cooling liquid flowing into the tank main body (21); and a second wall section (52) for blocking the upward flow of the cooling liquid along the first wall section (51).

Description

Technical Field

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

[0002] In recent years, efforts to achieve a low-carbon or decarbonized society have been actively underway. To reduce CO2 emissions and improve energy efficiency in vehicles, research and development related to electrification technologies have been conducted. With electrification, the power conversion devices and other equipment in vehicles generate significant heat, and therefore, cooling methods such as coolant are sometimes used to cool these devices.

[0003] For example, Patent Document 1 describes a vehicle equipment cooling system that includes a cooling circuit that circulates coolant to cool heat-generating equipment. The cooling circuit described in Patent Document 1 includes a storage tank with a coolant reservoir, the storage tank having a coolant inlet in the lower region of the reservoir. The storage tank absorbs volume changes caused by the thermal expansion of the coolant, or discharges air bubbles generated within the cooling circuit to the outside.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 7146865 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] In order to improve the cooling performance of the heat-generating equipment, the pump installed in the cooling circuit is set as a high-output pump to increase the flow rate of the coolant flowing in the cooling circuit. However, if the coolant inlet is set in the storage tank in the lower part of the coolant storage section, as in Patent Document 1, the flow velocity at the liquid surface in the storage tank increases, resulting in an unstable liquid surface and the possibility of air being drawn into the coolant.

[0009] The present invention provides a coolant tank that can reduce air entrainment at the liquid surface even when the flow of coolant is at a high flow rate.

[0010] Solution for solving the problem

[0011] This invention relates to a coolant tank, which is disposed in a cooling circuit for circulating coolant to cool heat-generating equipment mounted in a vehicle.

[0012] The coolant tank includes:

[0013] The main body of the tank is used to store the coolant;

[0014] An inlet, formed at the lower part of the tank body, is used to allow the coolant to flow in from the cooling circuit; and

[0015] An outlet is provided for allowing the coolant within the tank body to flow out into the cooling circuit.

[0016] The main body of the box has:

[0017] A first wall portion, which serves to disperse the flow of the coolant into the tank body; and

[0018] The second wall portion serves to block the upward flow of the coolant along the first wall portion.

[0019] Invention Effects

[0020] According to the present invention, by providing the first and second walls of the tank body, the flow of coolant toward the liquid surface is dispersed, so even if the coolant flowing in the cooling circuit is at a high flow rate, the flow velocity of the coolant at the liquid surface can be reduced, and air entrainment caused by liquid surface instability can be reduced. Attached Figure Description

[0021] Figure 1 This is a circuit diagram of a cooling circuit 1 provided with a storage tank 20, which is one embodiment of the coolant tank of the present invention.

[0022] Figure 2 This is a side view of the storage box 20 as seen from the rear.

[0023] Figure 3 This is an enlarged cross-sectional view of the storage box 20 showing the structure near the first wall portion 51 and the second wall portion 52.

[0024] Figure 4 The coolant level L is shown when the reservoir 20 is tilted at a specified angle while the vehicle is in motion.

[0025] Figure 5 This is a diagram of storage box 20 as viewed from the right.

[0026] Figure 6 It is viewed from the lower left along Figure 5 A three-dimensional view of the cross-section cut along line AA.

[0027] Figure 7 The storage box 200 of the comparative example is shown.

[0028] Explanation of reference numerals in the attached figures

[0029] 1 Cooling circuit

[0030] 13 Heating equipment

[0031] 20 Storage tank (coolant tank)

[0032] 21 main body

[0033] 21A Lower Box Component

[0034] 21B Upper Box Component

[0035] 22 Inlet

[0036] 23 Outlet

[0037] 42 Side wall portion

[0038] 51 First wall section

[0039] 52 Second wall section

[0040] 53 Third wall section

[0041] 54. Slit. Detailed Implementation

[0042] Hereinafter, an embodiment of the coolant reservoir of the present invention will be described with reference to the accompanying drawings. For convenience, the orientation will be determined according to the posture of the coolant reservoir mounted on the vehicle, with the front of the vehicle denoted 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 posture of the coolant reservoir mounted on the vehicle is varied and is not limited to the orientation shown in the accompanying drawings.

[0043] Figure 1 This is a circuit diagram of the cooling circuit 1, which cools the heat-generating device 13 installed in the vehicle. The vehicle may be, for example, a hybrid vehicle, an electric vehicle, a fuel cell vehicle, or a gasoline engine vehicle. Coolant circulates in the cooling circuit 1 to cool the heat-generating device 13. The heat-generating device 13 may be, for example, a power conversion unit (PCU) that controls the vehicle's drive motor and generates significant heat. However, the heat-generating device 13 is not limited to a power conversion unit; it may also be, for example, an engine, a high-voltage battery, or a charger. The coolant may be a liquid with high thermal conductivity and low freezing resistance, primarily composed of components such as ethylene glycol.

[0044] The cooling circuit 1 includes a pump 11 for circulating coolant, a radiator 12 for heat exchange between the coolant and the outside air, a heating device 13, and a storage tank 20 for storing coolant replenished into the cooling circuit 1. The pump 11, radiator 12, heating device 13, and storage tank 20 are arranged sequentially from the discharge side of the pump 11 toward the suction side.

[0045] Figure 2This is a side view of the storage tank 20 as seen from the rear. The storage tank 20 is an expansion tank that absorbs the volume change caused by the thermal expansion of the coolant circulating in the cooling circuit 1. In addition, it separates the bubbles generated in the cooling circuit 1 from the coolant (gas-liquid separation).

[0046] The storage tank 20 includes: a tank body 21 for storing coolant; an inlet 22 formed at the lower part of the tank body 21 for allowing coolant to flow in from the cooling circuit 1; an outlet 23 for allowing coolant in the tank body 21 to flow out into the cooling circuit 1; and a cover 24 for closing the inlet located at the upper part of the tank body 21. Coolant is replenished into the tank body 21 by removing the cover 24.

[0047] The box body 21 has a bottomed cylindrical shape that is longer in the vertical direction. The box body 21 has a lower box component 21A that forms the lower part of the box body 21 and an upper box component 21B that forms the upper part of the box body 21. The lower box component 21A and the upper box component 21B are respectively molded from resin or the like using a mold. The flange portion 31 of the lower box component 21A and the flange portion 41 of the upper box component 21B are fixed, for example, by welding. Since the fixing parts of the lower box component 21A and the upper box component 21B are located approximately at the center of the box body 21 in the vertical direction, it is possible to suppress the large size of the molds used to mold the lower box component 21A and the upper box component 21B, thereby reducing the cost of the molds.

[0048] When the main body 21 contains a normal amount of coolant, the lower tank component 21A is filled with coolant, and the coolant level L is located within the upper tank component 21B. More specifically, the coolant level L is located within a specified range of the upper tank component 21B. Figure 2 Within the range between MAX and MIN in the text.

[0049] Inlet 22 is formed at the lower part of the housing body 21 and is connected to a pipe (not shown) on the downstream side of the heating device 13. Inlet 22 is located at the right corner of the bottom 32 of the lower housing component 21A, facing upward to the left. Inlet 22 is obliquely opposed to the left wall (first wall 51 described later) of the side wall portion 33 of the lower housing component 21A.

[0050] Outlet 23 is formed at the lower part of the housing body 21 and is connected to a pipe (not shown) on the upstream side of the pump 11. Outlet 23 is located on the right side wall of the side wall portion 33 of the lower housing component 21A. Outlet 23 is located higher than inlet 22. Furthermore, a partition wall portion 25 is provided inside the housing body 21 between inlet 22 and outlet 23.

[0051] In recent years, in order to improve the cooling performance of the heat-generating device 13, it has been desirable to allow for a cooling circuit 1 with a high flow rate of coolant. In the case where the inlet 22 of the storage tank 20 provided in the cooling circuit 1 is formed in the lower part of the tank body 21, when the flow rate of coolant flowing in from the inlet 22 is high, the flow velocity of the coolant at the liquid surface L in the tank body 21 increases, causing the liquid surface L to become unstable, and air may be entrained into the coolant (i.e., air bubbles are mixed into the coolant).

[0052] Therefore, the storage tank 20 of this embodiment has a structure that can disperse the flow of coolant from the inlet 22 to the liquid surface L, thereby reducing the flow velocity at the liquid surface L. Specifically, the tank body 21 has: a first wall portion 51 for dispersing the flow of coolant flowing into the tank body 21; and a second wall portion 52 for blocking the coolant from flowing upward along the first wall portion 51.

[0053] Figure 3 This is an enlarged cross-sectional view of the storage box 20 showing the structure near the first wall portion 51 and the second wall portion 52. Figure 3 The thick solid arrow in the figure indicates the flow of coolant into the housing body 21 from the inlet 22. The first wall portion 51 extends vertically from the lower part of the housing 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 shape of the lower housing component 21A, and extends vertically from the bottom 32 of the lower housing component 21A to the flange portion 31.

[0054] The second wall portion 52 is disposed above the first wall portion 51 and extends in a direction orthogonal (approximately horizontal) to the flow direction of the coolant flowing upward along the first wall portion 51. The second wall portion 52 is located below the coolant surface L. Specifically, the second wall portion 52 is disposed on the left side of the upper housing member 21B and extends in a approximately horizontal direction from the flange portion 41 toward the inner side (right side) of the upper housing 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 housing 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 housing member 21B from the flange portion 41 toward the inner side of the upper housing member 21B.

[0055] The coolant flowing into the tank body 21 from the inlet 22 first contacts the first wall portion 51 opposite to the inlet 22. Then, the coolant flowing upwards along the first wall portion 51 contacts the second wall portion 52. Since the first wall portion 51 and the second wall portion 52 are arranged opposite to the flow of the coolant, even when the flow rate of the coolant flowing in from the inlet 22 is high, the coolant flow is sufficiently dispersed at the first wall portion 51 and the second wall portion 52 before reaching the liquid surface L, thereby reducing the flow velocity at the liquid surface L. Therefore, air entrainment at the liquid surface L can be reduced. Furthermore, the dispersion of the flow at the first wall portion 51 and the second wall portion 52 reduces the flow velocity at the liquid surface L, thus eliminating the need to enlarge the tank body 21 to reduce the flow velocity at the liquid surface L, enabling miniaturization of the storage tank 20.

[0056] The main body 21 also has a third wall portion 53, which extends downward from the second wall portion 52. The third wall portion 53 is located at the inner end (right end) of the second wall portion 52. Specifically, similar to the second wall portion 52, the third wall portion 53 is located on the upper box member 21B and is formed by extending the side wall portion 42 of the upper box member 21B downwards compared to the second wall portion 52. The lower end of the third wall portion 53 is located at approximately the same position as the flange portion 41 in the vertical direction. Furthermore, the third wall portion 53 extends in the front-rear direction (see reference). Figure 5 and Figure 6 ).

[0057] Since the main body 21 has a third wall portion 53, the coolant flowing upward along the first wall portion 51 can come into further contact with the third wall portion 53, thereby further dispersing the flow of the coolant.

[0058] Figure 4 The diagram shows the coolant level L when the coolant reservoir 20 mounted on the vehicle is temporarily tilted at a predetermined angle (e.g., 30 degrees). The second wall portion 52 and the third wall portion 53 are located at the lower part of the upper reservoir component 21B, configured such that even when the reservoir 20 is tilted, the coolant level L will not reach the second wall portion 52 and the third wall portion 53. This structure prevents air from accumulating in the area surrounded by the second wall portion 52 and the third wall portion 53.

[0059] Figure 5 This is a diagram of storage box 20 viewed from the right. Figure 6 It is viewed from the lower left along Figure 5 A three-dimensional view of the cross-section cut along line AA.

[0060] A slit 54 is provided on the third wall portion 53. The slit 54 is a downwardly opening cut formed in a part of the third wall portion 53. Because the slit 54 is provided, it is possible to prevent air contained in the coolant flowing in from the inlet 22 (i.e., air bubbles generated when the coolant flows in the cooling circuit 1) from accumulating in the area surrounded by the second wall portion 52 and the third wall portion.

[0061] The slit 54 is offset relative to the inlet 22 in the front-back direction extending from the third wall portion 53. As a result, the coolant flowing from the inlet 22 along the first wall portion 51 can easily contact the second wall portion 52 and the third wall portion 53 before passing through the slit 54, thereby improving the dispersion effect of the flow in the second wall portion 52 and the third wall portion 53.

[0062] Figure 7 A comparative example storage box 200 is shown. The storage box 200 of the comparative example differs from the storage box 20 of this embodiment in that it does not have a second wall portion 52.

[0063] Similar to the inlet 22 of the storage tank 20 of this embodiment, the inlet 22 of the storage tank 200 is formed at the lower part of the tank body 21, opposite to the first wall portion 51 of the tank body 21. The first wall portion 51 disperses the flow of coolant flowing into the tank body 21. The coolant flowing into the tank body 21 from the inlet 22 flows upward along the first wall portion 51, but since the second wall portion 52 is not provided in the comparative example storage tank 200, the coolant flowing along the first wall portion 51 reaches the liquid surface L before being sufficiently dispersed. Therefore, in the comparative example storage tank 200, when the flow rate of coolant flowing in from the inlet 22 is high, the flow velocity of the coolant at the liquid surface L increases, causing the liquid surface L to be unstable and air to be easily entrained in the coolant.

[0064] Furthermore, the main body 21 of the comparative example storage tank 200 has a lower tank component 21A and an upper tank component 21B, with the liquid level L located on the lower tank component 21A. When a second wall portion 52 is provided that extends substantially horizontally relative to the lower tank component 21A of the comparative example storage tank 200, the second wall portion 52 obstructs demolding when the lower tank component 21A is molded. Therefore, after molding the lower tank component 21A without the second wall portion 52, it is necessary to weld the second wall portion 52 separately. On the other hand, in this embodiment, the second wall portion 52 is formed by recessing the left side of the side wall portion 42 of the upper tank component 21B, so the second wall portion 52 does not obstruct demolding, and the second wall portion 52 can be integrally molded with the upper tank component 21B using a mold.

[0065] The present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to this embodiment. It is obvious that those skilled in the art will conceive of various modifications or alterations within the scope of the technical solution described, and it should be understood that these modifications and alterations also fall within the technical scope of the present invention. Furthermore, the constituent elements of the above embodiments can be combined arbitrarily without departing from the spirit of the invention.

[0066] At least the following items are described in this specification. The elements shown in parentheses are examples of components corresponding to those in the above embodiments, but the invention is not limited thereto.

[0067] (1) A coolant tank (storage tank 20) ​​disposed in a cooling circuit (cooling circuit 1) for circulating coolant to cool a heat-generating device (heat-generating device 13) mounted on a vehicle.

[0068] in,

[0069] The coolant tank includes:

[0070] The main body of the tank (tank body 21) is used to store the coolant;

[0071] An inlet (inlet 22), formed at the lower part of the tank body, is used to allow the coolant to flow in from the cooling circuit; and

[0072] Outlet (outlet 23) is used to allow the coolant inside the tank body to flow out to the cooling circuit.

[0073] The main body of the box has:

[0074] A first wall portion (first wall portion 51) is used to disperse the flow of the coolant flowing into the tank body; and

[0075] The second wall portion (second wall portion 52) is used to block the upward flow of the coolant along the first wall portion.

[0076] According to (1), the tank body has a first wall, which allows the coolant flowing in from the inlet to contact the first wall and disperse the flow. Furthermore, the tank body has a second wall for blocking the coolant from flowing upwards along the first wall, allowing the coolant flowing upwards (i.e., towards the liquid surface) to contact the second wall and further disperse the flow. Therefore, even if the coolant flowing in the cooling circuit is at a high flow rate, the flow velocity of the coolant at the liquid surface can be reduced, thus reducing air entrainment caused by liquid surface instability.

[0077] (2) The coolant tank according to (1), wherein,

[0078] The main body of the box also has a third wall (third wall 53) that extends downward from the second wall.

[0079] According to (2), the coolant can come into contact with the third wall and the flow can be further dispersed.

[0080] (3) The coolant tank according to (2), wherein,

[0081] A slit (slit 54) is provided in the third wall portion.

[0082] According to (3), it is possible to prevent air contained in the coolant from accumulating in the area surrounded by the second and third walls.

[0083] (4) The coolant tank according to (3), wherein,

[0084] The third wall portion extends in a first direction orthogonal to the vertical direction.

[0085] The slit is offset relative to the inlet in the first direction.

[0086] According to (4), even when slits are provided, the flow dispersion effect at the second and third walls can be improved.

[0087] (5) The coolant tank according to any one of (1) to (4), wherein,

[0088] The box body has a lower box component (lower box component 21A) constituting the lower part of the box body and an upper box component (upper box component 21B) constituting the upper part of the box body.

[0089] The second wall portion is formed by recessing a portion of the side wall portion (side wall portion 42) of the upper box component.

[0090] According to (5), when the lower box component and the upper box component are formed using a mold, the second wall will not cause any obstruction during demolding.

Claims

1. A coolant tank disposed in a cooling circuit for circulating coolant to cool heat-generating equipment mounted in a vehicle, wherein, The coolant tank includes: The main body of the tank is used to store the coolant; An inlet, formed at the lower part of the tank body, is used to allow the coolant to flow in from the cooling circuit; and An outlet is provided for allowing the coolant within the tank body to flow out into the cooling circuit. The main body of the box has: A first wall portion, which serves to disperse the flow of the coolant into the tank body; and The second wall portion serves to block the upward flow of the coolant along the first wall portion.

2. The coolant tank according to claim 1, wherein, The main body of the box also has a third wall portion that extends downward from the second wall portion.

3. The coolant tank according to claim 2, wherein, A slit is provided in the third wall portion.

4. The coolant tank according to claim 3, wherein, The third wall portion extends in a first direction orthogonal to the vertical direction. The slit is offset relative to the inlet in the first direction.

5. The coolant tank according to any one of claims 1 to 4, wherein, The box body has a lower box component constituting the lower part of the box body and an upper box component constituting the upper part of the box body. The second wall portion is formed by recessing a portion of the side wall portion of the upper box component.

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