Reserve tank

Abstract

To prevent outflow of air bubbles even if a fluid level in a reserve tank is largely fluctuated.SOLUTION: A reserve tank includes: an upper reserve tank body 2 having a hollow inner side; a lower reserve tank body 3 welded to the upper reserve tank body on a welding surface 9 in a sealed manner and having a hollow inner side; a cooling water inlet 4a that is provided in the upper reserve tank body 2 and to which cooling water W is introduced; a turning flow generation part 5 that is provided in the upper reserve tank body 2, has a curved inner surface with an arc cross section, and causes the cooling water W introduced from the cooling water inlet 4a to generate a turning flow; an inner cylinder part 6 formed within the turning flow generation part 5 and having a lower end extending to a lower side of the cooling water inlet; a cooling water outlet 7a that is provided in the lower reserve tank body 3 and from which the cooling water W is discharged; a partition plate 8 provided on the welding surface 9 for partition into the upper reserve tank body 2 and the lower reserve tank body 3; and a partition plate through hole 8a that is formed on the partition plate 8 and causes the cooling water W to flow from the upper reserve tank body 2 into the lower reserve tank body 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a reserve tank, and more particularly to a gas-liquid separation structure thereof. [Background technology]

[0002] Conventionally, "HVs (hybrid vehicles)," "EVs (electric vehicles)," and "PHVs (plug-in hybrid vehicles)" are equipped with motors and batteries, and coolant and hot water are constantly circulating to cool the motor, regulate the battery temperature, and air-condition the interior. Within these cooling circuits, reserve tanks are used to temporarily store excess coolant that expands as the fluid temperature rises.

[0003] Furthermore, if air bubbles get mixed into these cooling circuits, the pump performance and the efficiency of heat exchange will decrease, so some systems are provided with a gas-liquid separation mechanism in the reserve tank (for example, Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7287377 [Patent Document 2] Patent No. 7227865 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional reserve tanks, the fluid level changes significantly due to sudden acceleration and deceleration of the vehicle, centrifugal force when making sharp turns, and vibrations on rough roads.If the fluid level reaches the fluid outlet, air may escape from the fluid outlet and air bubbles may become mixed into the fluid.

[0006] The present invention has been made in consideration of the above points, and its purpose is to prevent air bubbles from escaping and becoming mixed into the fluid even when the fluid level in the reserve tank fluctuates greatly due to sudden acceleration / deceleration of the vehicle, centrifugal force on a sharp curve, or vibration on a rough road. [Means for solving the problem]

[0007] To achieve the above object, in the present invention, a partition plate is provided at an appropriate position within the reserve tank.

[0008] Specifically, in the first invention, A reserve tank provided in the fluid flow path for separating air bubbles from the fluid, The upper reserve tank body is hollow inside, a hollow lower reserve tank body that is hermetically welded to the upper reserve tank body at a welding surface; a fluid inlet provided in the upper reserve tank body and into which the fluid is introduced; a swirl flow generating section provided in the upper reserve tank body and having a curved inner surface with an arc-shaped cross section that generates a swirl flow in the fluid introduced from the fluid inlet; an inner cylindrical portion formed inside the swirl flow generating portion and having a lower end extending below the fluid inlet; a fluid outlet provided in the lower reserve tank body and through which the fluid is discharged; a partition plate provided on the welding surface to separate the upper reserve tank body from the lower reserve tank body; The partition plate has a partition plate through-hole formed therein, through which the fluid flows from the upper reserve tank body to the lower reserve tank body.

[0009] According to the above configuration, the swirl flow generating section, which has an inner wall with an arc-shaped cross section, generates a swirl flow in the fluid introduced through the fluid inlet, causing air bubbles contained in the fluid to gather at the center of the swirl flow and separate by moving toward the ceiling along the interior and outer periphery of the inner cylindrical section. Because the upper and lower reserve tank bodies are separated by the partition plate, air accumulated on the ceiling side of the upper reserve tank body is prevented from flowing into the lower reserve tank body, and the fluid flows into the lower reserve tank body through the partition plate through-holes formed in the partition plate. Meanwhile, even if the fluid level in the upper reserve tank body is greatly displaced due to sudden acceleration / deceleration of the vehicle, centrifugal force during sharp turns, or vibrations on rough roads, the fluid level remains within the upper reserve tank body, preventing air bubbles from escaping through the fluid outlet provided in the lower reserve tank body.

[0010] In the second invention, in the first invention, The partition plate is fitted into a recess formed in the welding surface.

[0011] With the above-mentioned configuration, when welding the upper and lower reserve tank bodies, the partition plate is fitted into the recess formed on the welding surface and welded, eliminating the need to weld the partition plate separately. This structure shortens the welding process.

[0012] In a third aspect of the present invention, in the first or second aspect of the present invention, A communication hole is formed in the upper side of the inner cylindrical portion, which communicates with the upper side of the upper reserve tank body.

[0013] According to the above-described configuration, air can freely flow in and out between the interior of the inner cylindrical portion and the upper reserve tank body, and the air is evenly collected on the ceiling side of the reserve tank.

[0014] In a fourth aspect of the present invention, in the first or second aspect of the present invention, The partition plate through-hole is formed as far outward as possible from the center of the swirling flow.

[0015] With the above configuration, centrifugal force is generated by the swirling flow, resulting in high pressure on the outside and low pressure in the center. Low-density bubbles gather at the center of the vortex due to this pressure difference. To prevent bubbles from escaping, the partition plate through-holes are located on the outside.

[0016] In the above configuration, the swirl flow generating portion does not necessarily have to be cylindrical, but rather needs to have an arc-shaped cross section that generates a swirl flow. It can also be an outer cylindrical portion with a C-shaped cross section and an open end. In this case, a partition plate through-hole can be provided on the outside of the outer cylindrical portion to prevent air bubbles from flowing into the lower reserve tank body. This configuration can be applied when there is not enough space to install a cylindrical swirl flow generating portion. [Effects of the Invention]

[0017] As explained above, according to the present invention, even if the fluid level in the reserve tank fluctuates greatly due to sudden acceleration / deceleration of the vehicle, centrifugal force on a sharp curve, or vibration on a rough road, the provision of a partition plate makes it possible to prevent air bubbles from escaping and becoming mixed into the fluid. [Brief explanation of the drawings]

[0018] [Figure 1] 2. FIG. 4 is a cross-sectional view of the reserve tank according to the first embodiment taken along line II in FIG. [Figure 2] 2 is a cross-sectional view of the reserve tank according to the first embodiment taken along line II-II in FIG. 1. FIG. [Figure 3] 2 according to a first modified example of the first embodiment. FIG. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 5, showing the reserve tank according to the second embodiment. [Figure 5] 5 is a cross-sectional view taken along line VV in FIG. 4, showing the reserve tank according to the second embodiment. [Figure 6] 8 is a cross-sectional view taken along line VI-VI in FIG. 7, showing a reserve tank according to a modified example of the second embodiment. [Figure 7] 7 is a cross-sectional view taken along line VII-VII in FIG. 6, showing a reserve tank according to a modified example of the second embodiment. [Figure 8]8 is a cross-sectional view of the reserve tank according to the third embodiment taken along line VIII-VIII in FIG. 9. [Figure 9] 9 is a cross-sectional view of the reserve tank according to the third embodiment taken along line IX-IX in FIG. 8. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0020] (Embodiment 1) 1 and 2 show a reserve tank 1 according to a first embodiment of the present invention. The reserve tank 1 is provided in a coolant flow path 20 of an automobile or the like, and separates air bubbles inside a coolant W as a fluid.

[0021] The reserve tank 1 is made of, for example, a resin molded product and includes an upper reserve tank body 2 with a hollow interior and a lower reserve tank body 3 with a hollow interior that is hermetically welded to the upper reserve tank body 2 at a welding surface 9. The material of the reserve tank 1 is not particularly limited, but, for example, the upper reserve tank body 2 and the lower reserve tank body 3 are each an injection-molded resin body.

[0022] In this embodiment, the upper reserve tank body 2 has a cylindrical shape that is open downward and has a ceiling with an upper flange 2a formed at its lower end, and a cooling water inlet pipe 4 protrudes from the middle of the side surface, offset from the center in a plan view, and inside the cooling water inlet pipe 4a is formed through which cooling water W is introduced. Pipes and the like that form a cooling water flow path 20 are connected to the cooling water inlet pipe 4.

[0023] Furthermore, a swirl flow generating section 5 having a curved inner surface with an arc-shaped cross section that generates a swirl flow in the cooling water W introduced from the cooling water inlet 4a is integrally molded with the upper reserve tank body 2. The swirl flow generating section 5 in this embodiment is formed by the inner wall of the cylindrical upper reserve tank body 2.

[0024] Inside the swirl flow generating section 5, a cylindrical inner tube 6 is formed concentrically with the central axis of the upper reserve tank body 2 and protrudes downward from the ceiling surface of the upper reserve tank body 2. A lower end opening 6a of the inner tube 6 is located above the upper flange 2a and below the cooling water inlet 4a. This lower end opening 6a causes the cooling water entering from the cooling water inlet 4a to first collide with the outer periphery of the inner tube 6 and then change direction towards the swirl flow generating section 5. It is positioned appropriately so that a stable swirl flow is generated even when the water level fluctuates.

[0025] A communication hole 6b is formed on the upper side of the inner cylindrical portion 6, which communicates with the upper space of the upper reserve tank body 2. This communication hole 6b allows air to freely flow in and out between the inside of the inner cylindrical portion 6 and the upper reserve tank body 2, and the air gathers evenly on the ceiling side of the reserve tank 1.

[0026] Furthermore, a cylindrical pressure relief portion 10 is formed concentrically at the upper end of the inner cylindrical portion 6 so as to protrude upward. A relief valve (not shown) is attached to this pressure relief portion 10, which also serves as a refill port for refilling the cooling water W. The relief valve allows the pressure in the reserve tank 1 to be released and also allows the cooling water W to be refilled into the cooling water flow path 20 when necessary. Note that, as will be described later, the pressure relief portion 10 does not necessarily have to be provided concentrically with the inner cylindrical portion 6.

[0027] On the other hand, the lower reserve tank body 3 has a bottomed cylindrical shape that is open at the top and has a lower flange 3a that corresponds to the upper flange 2a, and a cooling water outlet pipe 7 that protrudes downward from its underside and has a cooling water outlet 7a through which the cooling water W is discharged. The cooling water outlet pipe 7 is connected to piping and the like that form a cooling water flow path 20, as shown by a two-dot chain line.

[0028] The upper flange 2a and the lower flange 3a form an annular welding surface 9. In this embodiment, a stepped recess 9a is formed on the inner surface of the lower flange 3a. The outer peripheral edge of a disk-shaped partition plate 8 that separates the upper reserve tank body 2 and the lower reserve tank body 3 is fitted into the recess 9a of this welding surface 9. The upper flange 2a and the lower flange 3a are welded with the partition plate 8 fitted into the recess 9a formed in the welding surface 9, eliminating the need to weld the partition plate 8 separately. This structure shortens the welding process and allows the outer peripheral edges to be firmly fixed. The recess 9a may be provided on the upper flange 2a side or on both flanges 2a, 3a.

[0029] The partition plate 8 has, for example, a circular partition plate through-hole 8a formed therein, through which the cooling water W flows from the upper reserve-tank body 2 to the lower reserve-tank body 3. This partition plate through-hole 8a is desirably located as far outward as possible from the center of the swirling flow. In FIG. 2, it is located close to the inner wall of the swirling flow generating section, and in FIG. 9, which will be described later, it is located outside the outer cylinder portion 205a. In plan view, it is desirably that the cooling water outlet 7a is located offset from this partition plate through-hole 8a.

[0030] In this way, in this embodiment, when the upper reserve tank body 2 and the lower reserve tank body 3 are welded together in a sealed manner at the welding surface 9, the partition plate 8 is welded while fitted into the recess 9a formed on the welding surface 9, so there is no need to weld only the partition plate 8 individually, and the welding process can be shortened.

[0031] -Reserve tank operation- Next, the operation of the reserve tank 1 according to this embodiment will be described.

[0032] The reserve tank 1 is used, for example, by connecting a cooling water inlet pipe 4 and a cooling water outlet pipe 7 to piping that constitutes a cooling water flow path 20 of an electric vehicle, and cooling water is sucked into the cooling water inlet pipe 4 and discharged from the cooling water outlet pipe 7 by a pump or the like (not shown).

[0033] Although the cooling water flow path 20 is configured to prevent air bubbles from being mixed into the cooling water W, air bubbles may be mixed in due to cavitation or the like. In such cases, the air bubbles cause problems such as a decrease in pump performance and heat exchange efficiency. However, the reserve tank 1 not only stores the cooling water W but also serves to separate the air bubbles from the cooling water W.

[0034] As the cooling water W flows in through the cooling water inlet 4a of the cooling water inlet pipe 4, if it contains air bubbles, the bubbles will flow along the swirling flow in the direction of the arrows shown in Figure 2. As shown in Figure 1, the water surface Wa of the cooling water W is almost horizontal and stable within the inner cylindrical portion 6, but outside the inner cylindrical portion 6, the centrifugal force caused by the swirling flow causes it to rise radially outward. The action of the centrifugal force creates high pressure on the outside and low pressure in the center. Low-density bubbles gather at the center of the vortex due to this difference in pressure.

[0035] The separated air passes through a communication hole 6 b formed in the inner cylindrical portion 6 and collects on the ceiling side of the upper reserve tank body 2 .

[0036] At this time, the upper reserve tank body 2 and the lower reserve tank body 3 are separated by the partition plate 8, so that the air accumulated on the ceiling side of the reserve tank body 1 is prevented from flowing into the lower reserve tank body 3.

[0037] The cooling water W flows through the partition plate through-holes 8a formed in the partition plate 8 into the lower reserve tank body 3, and is discharged from the cooling water outlet 7a.

[0038] On the other hand, even if the liquid level Wa of the cooling water W in the reserve tank 1 fluctuates greatly due to sudden acceleration / deceleration of the vehicle, centrifugal force on a sharp curve, or vibration on a rough road, the liquid level Wa remains in the upper reserve tank body 2 due to the presence of the partition plate 8, thereby preventing air bubbles from flowing out from the cooling water outlet 7a provided in the lower reserve tank body 3.

[0039] Therefore, with the reserve tank 1 of this embodiment, even if the fluid level in the reserve tank 1 fluctuates greatly due to sudden acceleration / deceleration of the vehicle, centrifugal force on a sharp curve, or vibration on a rough road, it is possible to prevent air bubbles from escaping from the cooling water outlet 7a.

[0040] -Variations- 3 shows a reserve tank 1' according to a modification of the first embodiment of the present invention, which differs from the first embodiment in particular in the shape of the cooling water inlet 4a' of the cooling water inlet pipe 4'. Note that in the following embodiments and modifications, the same parts as those in FIGS. 1 and 2 are designated by the same reference numerals, and detailed description thereof will be omitted.

[0041] In this modification, an inlet partition wall 4b' is formed around the periphery of the cooling water inlet 4a' to change the flow direction of the cooling water W. Specifically, the inlet partition wall 4b' is formed to be curved so that the flow path narrows toward the cooling water inlet 4a' in plan view.

[0042] The cooling water W flowing in from the cooling water inlet 4a' is forcibly changed in flow direction by the inlet partition wall 4b', and collides with the swirl flow generating section 5, generating a swirl flow.

[0043] In this way, the inlet partition wall 4b' can generate a stronger swirling flow of the cooling water W, which is extremely useful when it is not possible to offset the cooling water inlet pipe 4' relative to the reserve tank 1' due to layout or other issues.

[0044] (Embodiment 2) 4 and 5 show a reserve tank 101 according to a second embodiment of the present invention, which differs from the first embodiment mainly in that the shapes of the upper reserve tank body 102 and the lower reserve tank body 103 are different.

[0045] The shape of the reserve tank 101 needs to be adapted to the vehicle layout. In addition, since the reserve tank 101 needs to accommodate the increased fluid due to volume expansion at high temperatures, a certain amount of volume is required. For this reason, the reserve tank 101 may have not only a cylindrical shape as in the first embodiment, but also a rectangular parallelepiped shape as in this embodiment. In addition to a rectangular parallelepiped, the reserve tank 101 may have an irregular polyhedral shape adapted to the vehicle layout.

[0046] In this embodiment, the upper reserve tank body 102 and the lower reserve tank body 103 have a rectangular cross section. The swirl flow generating portion 105 is formed by the inner wall of an outer cylinder portion 105a that is concentric with the inner cylinder portion 6 formed in the upper reserve tank body 102. The lower end of the outer cylinder portion 105a extends to the partition plate 108. A cooling water outlet 105b is formed at the lower end of the outer cylinder portion 105a, and the cooling water flows into other areas within the upper reserve tank body 102 through this cooling water outlet 105b.

[0047] A communication hole 105c is formed on the upper side of the outer cylindrical portion 105a, similar to the inner cylindrical portion 6, so that air accumulated on the ceiling side of the outer cylindrical portion 105a flows through this communication hole 105c into the cavity inside the upper reserve tank body 102. This communication hole 105c and the communication hole 6b of the inner cylindrical portion 6 may be provided at any position on each partition wall as long as they are in the air space on the ceiling side.

[0048] The cooling water W that has flowed into other regions within the upper reserve tank body 102 passes through a partition plate through-hole 108a formed outside the outer tubular portion 105a of a rectangular partition plate 108 and at a position away from the cooling water outlet 105b, and flows into the lower reserve tank body 103. At this time, the air bubbles have already been separated, so the separated cooling water flows into the lower reserve tank body 103.

[0049] Furthermore, since the partition plate 108 is formed, even in the reserve tank 101 of this embodiment, even if the fluid level in the reserve tank 1 fluctuates greatly due to sudden acceleration / deceleration of the vehicle, centrifugal force on a sharp curve, or vibration on a rough road, it is possible to prevent air bubbles from escaping from the cooling water outlet 7a.

[0050] -Variations- 6 and 7 show a modification of the second embodiment of the present invention, which differs from the second embodiment in that the cylindrical pressure relief portion 10 and other parts are positioned differently.

[0051] When the upper reserve tank body 102' is large as in this modified example, the pressure relief part 10 does not need to be provided directly above the inner cylindrical part 6, and may be provided at a different position on the upper reserve tank body 102.

[0052] In addition, the cooling water outlet pipe 107' forming the cooling water outlet 7a may be provided on the side of the lower reserve tank main body 102 in accordance with the layout, as shown by the two-dot chain line in Figure 7, rather than on the bottom surface of the lower reserve tank main body 102 as shown in Figure 6.

[0053] (Embodiment 3) 8 and 9 show a reserve tank 201 according to a third embodiment of the present invention, which differs from the first and second embodiments in that the shape of the swirl flow generating portion 205 is different.

[0054] In this embodiment, the upper reserve tank body 202 and the lower reserve tank body 203 are rectangular cylindrical bodies with square cross sections and formed with flanges 202a, 203a, respectively. The swirl flow generating section 205 is formed by the inner surface of an outer cylindrical section 205a that extends downward from the top surface of the upper reserve tank body 202 to the partition plate 208 and has a C-shaped cross section with the cooling water inlet 4a side missing. In this embodiment, the partition plate through-hole 208a is located on the outside of the outer cylindrical section 205a and is positioned away from the center of the swirl flow.

[0055] The cooling water inlet 4a is formed on the inner surface of the upper reserve tank body 202 and is separated from the outer cylindrical portion 205a. The cooling water W flowing in from the cooling water inlet 4a collides with the outer surface of the inner cylindrical portion 6 and flows as a swirling flow due to the swirling flow generating portion 205. Air bubbles with a low specific gravity gather at the center of the vortex and gather inside and along the outer periphery of the inner cylindrical portion 6 on the ceiling side of the tank body 2.

[0056] The cooling water W in the upper reserve tank body 202 flows into the lower reserve tank body 203 through a partition plate through-hole 208 a formed in a rectangular partition plate 208 .

[0057] Then, the cooling water W from which the bubbles have been separated is discharged from the cooling water outlet 7a.

[0058] In this way, the swirl flow generating part 205 does not necessarily have to be cylindrical, but may have at least a curved surface portion that generates a swirl flow, and may be a C-shaped cylinder with one open end. In that case, it should be located outside the outer cylindrical part 205a, away from the center of the swirl flow, so as to prevent air bubbles from flowing into the lower reserve tank body 3.

[0059] The swirling flow generating section 205 of this embodiment can be applied when there is no space to provide the cylindrical swirling flow generating section 5, 105 of the other embodiments.

[0060] In this embodiment, too, a partition plate 208 is provided, so that air bubbles can be prevented from escaping even if the fluid level in the reserve tank 1 fluctuates greatly due to sudden acceleration / deceleration of the vehicle, centrifugal force on a sharp curve, or vibration on a rough road.

[0061] It should be noted that the above-described embodiments are essentially preferred examples and are not intended to limit the scope of the present invention, its applications, or uses. [Explanation of symbols]

[0062] 1,1',101,201 Reserve tank 2,102,102',202 Upper reserve tank body 2a, 202a Upper flange 3,103,203 Lower reserve tank body 3a,203a Lower flange 4,4' cooling water inlet pipe 4a,4a' Cooling water inlet (fluid inlet) 4b' Entrance partition wall 5,105,205 Swirl flow generation part 6 Inner cylinder 6a Bottom opening 6b Communication hole 7,107' Cooling water outlet pipe 7a Cooling water outlet (fluid outlet) 8,108,208 Partition 8a, 108a, 208a Partition plate through holes 9 Welding surface 9a Recess 10 Pressure relief section 20 Cooling water flow path (fluid flow path) 105a, 205a Outer cylinder 105b Cooling water outlet 105c Communication hole W Cooling water (fluid) Wa liquid level (fluid liquid level)

Claims

1. A reserve tank provided in the fluid flow path for separating air bubbles from the fluid, The upper reserve tank body is hollow inside, a hollow lower reserve tank body that is hermetically welded to the upper reserve tank body at a welding surface; a fluid inlet provided in the upper reserve tank body and into which the fluid is introduced; a swirl flow generating section provided in the upper reserve tank body and having a curved inner surface with an arc-shaped cross section that generates a swirl flow in the fluid introduced from the fluid inlet; an inner cylindrical portion formed inside the swirl flow generating portion and having a lower end extending below the fluid inlet; a fluid outlet provided in the lower reserve tank body and through which the fluid is discharged; a partition plate provided on the welding surface to separate the upper reserve tank body from the lower reserve tank body; a partition plate through-hole formed in the partition plate through which the fluid flows from the upper reserve tank body to the lower reserve tank body; A reserve tank characterized by the above.

2. The partition plate is fitted into a recess formed on the welding surface.

2. The reserve tank according to claim 1, wherein:

3. A communication hole communicating with the upper side of the upper reserve tank body is formed on the upper side of the inner cylindrical portion.

3. The reserve tank according to claim 1 or 2.

4. The partition plate through-hole is formed as far outward as possible from the center of the swirling flow.

3. The reserve tank according to claim 1 or 2.

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