Vehicle water pump and vehicle including the same

Abstract

To provide a vehicle water pump which can avoid cavitation with a simple structure, and to provide a vehicle including the vehicle water pump.SOLUTION: A vehicle water pump includes: a pump case; a suction port for suctioning water; a discharge port for discharging water; and an impeller housed in the pump case. The impeller includes: a first impeller having a shaft part which is set as a center of rotation, and a plurality of blade parts which are radially disposed around the shaft part; and a second impeller which is disposed between the first impeller and the pump case so as to be rotatable by a fluid force of water flowing from the suction port to the discharge port.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a water pump for a vehicle and a vehicle including the same. [Background technology]

[0002] Patent document 1 discloses a configuration in which a water pump is provided with a bypass passage that connects the suction port and the discharge port, and the bypass passage is connected to the suction port so that cooling water flows in a tangential direction to the inner wall of the piping.

[0003] Patent document 2 discloses a vehicle cooling device in which a guide wall is formed inside the thermostat housing downstream of the sealing surface of the main valve, and the guide wall is inclined in the same direction as the rotational direction of the cooling water flowing inside the water pump to guide the cooling water.

[0004] Patent Document 3 discloses the configuration of a centrifugal water pump. Specifically, in a centrifugal water pump that includes an impeller, a pump case, a suction port, and a discharge port, the impeller includes an impeller shaft and a plurality of blades circumferentially surrounding the impeller shaft, and the impeller is rotated to pump water by centrifugal force, the impeller shaft is tapered with the base of the impeller as its bottom surface, and grooves are formed on the side surface of the impeller shaft radially from the shaft end toward the blades. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2007-009851 [Patent Document 2] Patent Publication No. 2004-263586 [Patent Document 3] Patent Publication 2014-185614 Summary of the Invention [Problem to be solved by the invention]

[0006] This is not limited to the vehicle disclosed in the above-mentioned document, but generally in vehicle water pumps, there is a problem that the flow speed of the cooling water increases near the suction port of the impeller, causing a decrease in the pressure of the cooling water and the occurrence of cavitation.

[0007] There is also concern that shock waves generated by the repeated generation and disappearance of bubbles due to cavitation will strike the surface of the impeller blades and gradually erode the surface of the impeller.

[0008] The present disclosure has been made in consideration of the above-mentioned problems as an example, and aims to provide a vehicle water pump and a vehicle equipped with the same that can avoid the above-mentioned cavitation with a simple configuration. [Means for solving the problem]

[0009] In order to solve the above problems, a vehicle water pump in one embodiment of the present disclosure comprises a pump case, an inlet for sucking in water, a discharge outlet for discharging water, and an impeller housed within the pump case, wherein the impeller includes a first impeller having a shaft portion that serves as the center of rotation and a plurality of blade portions arranged radially around the shaft portion, and a second impeller that is arranged between the first impeller and the pump case and can be rotatable by the fluid force of water flowing from the inlet to the discharge outlet. Effect of the Invention

[0010] According to the present disclosure, it is possible to provide a vehicle water pump capable of avoiding cavitation with a simple configuration, and a vehicle including the same. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram illustrating a schematic diagram of an example of a vehicle to which the present disclosure can be applied; [Diagram 2] FIG. 2 is a diagram showing a schematic arrangement of a water pump of a vehicle according to the present disclosure. [Diagram 3] 1 is a cross-sectional view illustrating a schematic diagram of a water pump according to the present disclosure. [Figure 4] FIG. 2 is a diagram illustrating a first impeller in the water pump of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Next, a preferred embodiment for carrying out the present disclosure will be described. In the following description, for the sake of convenience, the vehicle height direction of the vehicle is defined as the Z direction, the vehicle length direction as the X direction, and the vehicle width direction perpendicular to the Z direction and the X direction as the Y direction. However, the present disclosure is not dependent on the above-mentioned definition of directions, and it goes without saying that the scope of the claims is not unduly restricted.

[0013] In addition, for configurations other than those described in detail below, publicly known vehicle structures, on-board equipment, and elemental technologies thereof, including the above-mentioned patent documents, may be appropriately supplemented. In this disclosure, a configuration in which a drive pulley of a water pump rotates via a timing chain is described as an example, but the present disclosure is not limited thereto, and the present disclosure is also applicable to a water pump that obtains driving force from an electric motor. Furthermore, in this disclosure, a so-called horizontally opposed engine is described as an example in which cylinders are arranged horizontally on the left and right of a crankshaft, and a pair of pistons facing each other on the left and right reciprocate horizontally, but the present disclosure is not limited thereto, and a V-type or in-line type may also be used.

[0014] [Vehicle 1] The configuration of a vehicle 1 according to an embodiment will be described with reference to FIGS. As shown in Fig. 1, a vehicle 1 has a front space FS (engine compartment) arranged under a bonnet at the front of the vehicle. An engine EG as shown in Fig. 2 is mounted in the front space FS.

[0015] [Engine EG] As shown in FIG. 2, the engine EG includes a cylinder block SD, a cylinder head HD, a crankshaft SF, a timing chain TC, and a water pump 100.

[0016] The cylinder block SD includes a first cylinder block SDA and a second cylinder block SDB. A crankshaft SF is disposed between the first cylinder block SDA and the second cylinder block SDB. The first cylinder block SDA and the second cylinder block SDB are disposed facing each other in the horizontal direction (left-right direction) with the crankshaft SF in between. The crankshaft SF is supported rotatably (rotatably) by the cylinder block SD (the first cylinder block SDA and the second cylinder block SDB).

[0017] The cylinder head HD includes a first cylinder head HDA and a second cylinder head HDB. The first cylinder head HDA is connected to the first cylinder block SDA on the side opposite to the second cylinder block SDB. The second cylinder head HDB is connected to the second cylinder block SDB on the side opposite to the first cylinder block SDA.

[0018] In this manner, the engine EG has the first cylinder head HDA, the first cylinder block SDA, the second cylinder block SDB, and the second cylinder head HDB connected side by side in the horizontal direction.

[0019] A chain cover (not shown) is connected to the front side of the cylinder block SD and the cylinder head HD. The chain cover covers the front sides of the cylinder block SD and the cylinder head HD and forms a chain chamber between the cylinder block SD and the cylinder head HD.

[0020] The first cylinder head HDA rotatably supports a first intake camshaft ICa and a first exhaust camshaft ECa. The second cylinder head HDB rotatably supports a second intake camshaft ICb and a second exhaust camshaft ECb. The intake camshafts ICa and ICb are positioned vertically above the exhaust camshafts ECa and ECb.

[0021] A first intake cam sprocket ISRa is attached to the front end of the first intake camshaft ICa, and a second intake cam sprocket ISRb is attached to the front end of the second intake camshaft ICb.

[0022] A first exhaust cam sprocket ESRa is attached to the front end of the first exhaust camshaft ECa, and a second exhaust cam sprocket ESRb is attached to the front end of the second exhaust camshaft ECb.

[0023] The water pump 100 has a function of circulating cooling water (coolant) for the engine EG. As an example, the water pump 100 is attached to the front side of the second cylinder block SDB, between the crankshaft SF and the second cylinder head HDB. The water pump 100 rotates by using the driving force of the engine EG. More specifically, the water pump 100 rotates by obtaining the driving force from the rotation of the timing chain TC. A drive pulley 101 is attached to an end of the water pump 100.

[0024] A drive sprocket SFS is attached to the front end of the crankshaft SF. In the chain chamber, a timing chain TC is stretched around the drive sprocket SFS, first intake cam sprocket ISRa, first exhaust cam sprocket ESRa, drive pulley 101, second intake cam sprocket ISRb, and second exhaust cam sprocket ESRb.

[0025] When the crankshaft SF rotates, the first intake camshaft ICa, the first exhaust camshaft ECa, the drive pulley 101, the second intake camshaft ICb, and the second exhaust camshaft ECb are each rotationally driven via the timing chain TC.

[0026] [Water Pump] The water pump 100 of the present disclosure will be described in further detail with reference to Fig. 3. The water pump 100 of the present disclosure includes a pump case 10, an intake port 20 for sucking in water, an exhaust port 30 for exhausting water, and an impeller 40 housed within the pump case 10. The arrow in Fig. 3 indicates the rotation direction of the impeller 40.

[0027] The pump case 10 is a case having a known shape capable of housing the impeller 40, and is provided with a bottom surface and a flange surface, with one surface on the upper surface side being open. Fastening portions 15a-15f are formed on the outer edge portion constituting the flange surface of the pump case 10. At the fastening portions 15a-15f, the pump case 10 is screwed to a pump case or crank case (not shown). The pump case 10 and a pump cover (not shown) that covers the opening of the pump case 10 form a substantially circular pump chamber 13 in which the impeller 40 is housed.

[0028] The suction port 20 is connected to a cooling water hose extending from a radiator (not shown). The suction port 20 guides the cooling water flowing in from the cooling water hose to the pump chamber 13. The suction port 20 is disposed at a position opposite to a discharge port 30 (described later), so that a rotational force can be applied to the cooling water inside the pump chamber.

[0029] The discharge port 30 is a pipe portion provided in the pump case 10. The discharge port 30 is formed so as to extend in a tangential direction from the pump chamber 13. The discharge port 30 is fitted and connected to, for example, a cooling water inlet (not shown) in a cylinder block SD of the engine EG.

[0030] The impeller 40 is a centrifugal impeller that uses centrifugal force to pump the cooling water. The rotation of the impeller 40 can send the cooling water to the discharge port 30. The impeller 40 of the present disclosure includes at least a first impeller 43 disposed in the center of the pump chamber 13, and a second impeller 45 disposed outside the first impeller 43 and between the pump case 10 and the first impeller 43.

[0031] The first impeller 43 is connected to the pump case 10 with the first shaft portion 431 as the center of rotation. The first impeller 43 includes a plurality of blade portions 43a to 43f that are radially arranged circumferentially around the first shaft portion 431.

[0032] The second impeller 45 is a ring-shaped or cylindrical member housed inside the pump chamber 13. The second impeller 45 is rotatable by the fluid force of the cooling water rotated inside the pump case 10 by the first impeller 43. In other words, the second impeller 45 is not connected to the pump case 10 and the first shaft portion 431. However, the second impeller 45 may be journaled on the first shaft portion 431 as long as the second impeller 45 is freely rotatable with respect to the first impeller 43 outside the first impeller 43.

[0033] The second impeller 45 will be described in more detail with reference to Fig. 4. As shown in Fig. 4, the second impeller 45 has a shallow ring shape or a cylindrical shape with a height similar to that of the first impeller 43. The second impeller 45 can be made of a metal material such as steel or titanium, or a hard resin material. The material of the second impeller 45 may be the same as that of the first impeller 43, or may be a different material.

[0034] The size and thickness of the second impeller 45 are not particularly limited as long as the second impeller 45 can rotate outside the first impeller 43 in the pump case 10. As shown in FIG. 4, a plurality of convex portions 47 are provided on the inner surface of the second impeller 45. A plurality of concave portions 49 are provided on the outer surface of the second impeller 45. In FIG. 4, five convex portions 47a to 47e are shown as the convex portions 47, and five concave portions 49a to 49e are shown as the concave portions 49. However, this is not limited thereto, and concave portions or convex portions may be formed only on either the inner or outer side of the second impeller 45. Furthermore, the convex portions 47 may be provided on both the inner and outer sides of the second impeller 45. The shape (height, length, interval, etc.) of the convex portions 47 or the concave portions 49 is not particularly limited as long as the second impeller 45 can rotate by the rotational force of the cooling water.

[0035] Furthermore, as long as the second impeller 45 can be rotated by the torque of the cooling water, at least a part of the side wall of the second impeller 45 may be formed in a mesh shape. By forming the side wall of the second impeller 45 into a mesh shape, not only is the torque of the cooling water applied to the mesh portion to rotate the second impeller 45, but also the cooling water can communicate between the inside and outside of the second impeller 45, which is more preferable from the viewpoint of reducing the pressure difference of the fluid (cooling water).

[0036] Coolant pressurized by the water pump 100 of the present disclosure cools various parts of the engine EG, and the heated coolant is then sent to the radiator where it is cooled and then sent back to the water pump 100. Cavitation in a water pump generally occurs when the pressure difference in the coolant around the blades of the impeller increases.

[0037] In the present disclosure, the second impeller 45 is disposed outside the first impeller 43 connected to the rotating shaft. The cooling water introduced from the suction port 20 is given a rotational force by the first impeller 43. At that time, a pressure difference occurs in the fluid (cooling water) between the front side R1 of rotation and the rear side R2 of rotation of any blade portion (for example, the blade portion 43a). On the other hand, the second impeller 45 of the present disclosure obtains a rotational force in the same direction as the first impeller 43 by the cooling water given a rotational force by the first impeller 43. Therefore, the rotation of the second impeller 45 reduces the pressure difference between the fluid on the front side R1 of rotation and the rear side R2 of rotation of any blade portion (for example, the blade portion 43a) of the first impeller 43. In this way, in the water pump 100 of the present disclosure, the pressure difference caused by the rotation of the first impeller 43 is suppressed by the rotation of the second impeller 45, thereby suppressing the occurrence of cavitation in the pump chamber 13.

[0038] Although the preferred embodiment of the present disclosure has been described in detail above with reference to the accompanying drawings, the present disclosure is not limited to such examples. It is clear that a person having ordinary knowledge in the technical field to which the present disclosure belongs may attempt to further modify the above-mentioned embodiment within the scope of the technical ideas described in the claims, and it is understood that these also naturally belong to the technical scope of the present disclosure. [Explanation of symbols]

[0039] 100: water pump, 10: pump case, 20: suction port, 30: discharge port, 40: impeller, 43: first impeller, 45: second impeller

Claims

1. The pump includes a pump case, a suction port for sucking in water, a discharge port for discharging water, and an impeller housed in the pump case, The impeller comprises: A first impeller including a first shaft portion serving as a rotation center and a plurality of blade portions radially arranged circumferentially around the first shaft portion; a second impeller disposed between the first impeller and the pump case so as to be rotatable by a fluid force of water flowing from the suction port to the discharge port; A water pump for a vehicle comprising:

2. The water pump for a vehicle according to claim 1 , wherein a center of rotation of the second impeller is not connected to the first shaft portion.

3. The water pump for a vehicle according to claim 1 or 2, wherein the second impeller has a ring shape or a cylindrical shape.

4. The water pump for a vehicle according to claim 1 or 2, wherein the second impeller has a plurality of recesses or protrusions on a surface thereof.

5. A vehicle comprising the water pump according to claim 1 or 2.

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