WO2015136861A1

WO2015136861A1 - Cooling system

Info

Publication number: WO2015136861A1
Application number: PCT/JP2015/000912
Authority: WO
Inventors: 武司山本
Original assignee: 株式会社デンソー
Priority date: 2014-03-12
Filing date: 2015-02-24
Publication date: 2015-09-17
Also published as: JP2015172362A

Abstract

A cooling system is provided with: a pump (2) having a casing (13) in which an intake port (11) for drawing in a coolant and a discharge port (12) for discharging the coolant are formed, and an impeller (15) that is housed inside the casing and rotates with a rotating shaft (14) so as to draw in the coolant and discharge the drawn-in coolant in a direction that intersects with the rotating shaft; a rubber hose (7) connected to the intake port and through which the coolant flows; and a coil (21, 22) formed by winding a linear member into a spiral shape and placed inside the rubber hose so as to be in contact with the inner peripheral surface of the rubber hose.

Description

Cooling system

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2014-049035 filed on March 12, 2014, the disclosure of which is incorporated herein by reference.

The present disclosure relates to a cooling system that cools an object to be cooled using a coolant.

Patent Document 1 describes a centrifugal pump in which cooling liquid is sucked into an impeller in a direction parallel to the rotation axis of the impeller and discharged from the impeller in a direction orthogonal to the rotation axis of the impeller. . The pump is provided with a mechanism for generating a swirling flow of the cooling liquid in the casing in a flow path from the suction port to the impeller in the casing that houses the impeller.

According to this, by generating a swirl flow in the coolant sucked into the impeller, it is possible to reduce the flow loss that occurs when the coolant is sucked into the impeller, and to improve the pump efficiency. In the prior art of Patent Document 1, a swirl flow swirling in the same direction as the rotation direction of the impeller is generated.

JP 2012-92698 A

By the way, in a vehicle cooling system, a rubber hose is used as a pipe connected to a pump inlet. Since the rubber hose can be bent and deformed, it can be mounted on the vehicle and has a high degree of freedom in piping layout when mounted on the vehicle. Furthermore, the rubber hose does not require a complicated seal structure at the pipe connection portion, and is lightweight. Therefore, the fuel consumption of the vehicle can be improved as compared with the case where a pipe heavier than the rubber hose is employed.

And in the cooling system for vehicles using a rubber hose, the mechanism which generates the swirl | vortex flow of a cooling water in the flow path from the inlet to the impeller among the casings of a pump by applying the prior art of the above-mentioned patent document 1 It is conceivable to provide As a result, the pump efficiency can be improved and the output of the pump can be increased.

However, according to the examination by the inventors of the present application, even when the pump output is increased in this way, when the pump is actually operated at a large output, the pressure on the suction port side of the casing decreases. Therefore, the rubber hose may be crushed depending on the temperature condition of the coolant. In this case, it becomes impossible to send out a coolant having a necessary flow rate.

This indication aims at providing the cooling system which can improve pump efficiency, preventing collapse of a rubber hose in view of the above-mentioned point.

The cooling system of the present disclosure includes a casing formed with a suction port for sucking a coolant and a discharge port for discharging the coolant, and is accommodated in the casing, and sucks the coolant by rotating together with the rotating shaft. A pump having an impeller that discharges the sucked coolant in a direction intersecting the rotation axis, a rubber hose that is connected to the suction port and through which the coolant flows, and is arranged inside the rubber hose so as to be in contact with the inner peripheral surface of the rubber hose And a coil in which a linear member is spirally wound.

In the present disclosure, by arranging the coil inside the rubber hose connected to the suction port of the casing, not only the rubber hose is reinforced, but also a swirl flow is generated in the coolant flowing inside the rubber hose according to the shape characteristic of the coil. Can do. Accordingly, it is possible to improve the pump efficiency by reducing the flow loss that occurs when the coolant is sucked into the impeller while preventing the rubber hose from being crushed due to the pressure drop on the suction port side of the casing.

It is a figure which shows the cross-sectional structure of the pump in 1st Embodiment, and a cooling system. It is a perspective view of an impeller inside a pump and a coil inside a rubber hose in the first embodiment. It is a measurement result of the pump efficiency in the cooling system of 1st, 2nd embodiment and the comparative example 1. FIG. It is a perspective view of the impeller inside a pump and the coil inside a rubber hose in 2nd Embodiment.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.
(First embodiment)
In the present embodiment, the cooling system of the present disclosure is applied to a cooling system for a vehicle that is mounted on a vehicle and cools an engine for the vehicle with cooling water.

As shown in FIG. 1, the cooling system 1 for vehicles of this embodiment is equipped with the electric water pump 2, the engine 3, the radiator 4, and the

piping

5, 6, and 7 which connect these. . The water pump 2, the engine 3, and the radiator 4 are connected to each other by

pipes

5, 6, and 7. Thereby, a cooling water circuit in which the cooling water circulates in the order of the water pump 2, the engine 3, and the radiator 4 is configured. In the present embodiment, an ethylene glycol aqueous solution is used as the cooling water. In addition, the water pump 2, the engine 3, and the cooling water of the present embodiment correspond to a pump, a heating element mounted on the vehicle, and a coolant, respectively.

The water pump 2 distributes cooling water. Specifically, the water pump 2 includes a casing 13, an impeller (impeller) 15, and an electric motor 16. The casing 13 has a suction port 11 for sucking cooling water and a discharge port 12 for discharging cooling water. The impeller 15 is accommodated inside the casing 13 and rotates together with the rotating shaft 14. The electric motor 16 rotationally drives the impeller 15. In this embodiment, a centrifugal pump is employed as the water pump 2.

Casing 13 is made of resin. The suction port 11 of the casing 13 is formed of a cylindrical portion, and the axis X1 of the rotary shaft 14 and the axis X2 of the suction port 11 are aligned. Thereby, cooling water is sucked into the impeller 15 from the suction port 11 in a direction parallel to the rotation shaft 14. The casing 13 has a scroll portion 17 that forms a spiral cooling water passage on the radially outer side of the impeller 15. The end of the scroll part 17 is the discharge port 12.

The impeller 15 is made of resin. The impeller 15 has a closed structure having two

disk parts

15a and 15b and a plurality of blade parts 15c arranged between the two

disk parts

15a and 15b. The rotating shaft 14 is made of metal and is sealed with a mechanical seal 18 inside the casing 13.

The engine 3 is an internal combustion engine mounted on a vehicle, and is an object to be cooled that is cooled by cooling water. The engine 3 has a cooling water inlet 3a through which cooling water flows into the interior, and a cooling water outlet 3b through which cooling water flows out to the outside. The cooling water inlet 3 a of the engine 3 is connected to the discharge port 12 of the water pump 2 via the pipe 5.

The radiator 4 is a heat exchanger that exchanges heat between cooling water and air to dissipate the cooling water. The radiator 4 has a cooling water inlet 4a through which cooling water flows into the interior, and a cooling water outlet 4b through which cooling water flows out to the outside. The cooling water inlet 4 a is connected to the cooling water outlet 3 b of the engine 3 through the pipe 6. The cooling water outlet 4b is connected to the suction port 11 of the water pump 2 through a rubber hose 7 as a pipe.

The rubber hose 7 is a rubber hose (pipe) that bends freely. As the rubber hose 7, a general rubber hose used in a vehicle cooling system can be employed. The rubber hose 7 has one end connected to the suction port 11 of the water pump 2 and the other end connected to the cooling water outlet 4 b of the radiator 4. Cooling water flows inside the rubber hose 7 from the radiator 4 toward the water pump 2. A coil 21 is located inside the rubber hose 7 so as to be in contact with the inner peripheral surface of the rubber hose 7.

The coil 21 is formed by spirally winding a metal linear member having high corrosion resistance such as stainless steel. The coil 21 reinforces the rubber hose 7 and generates a swirling flow in the cooling water flowing inside the rubber hose 7.

For this reason, the thickness of the linear member is set so that the strength against the compressive force in the radial direction of the coil is higher than that of the rubber hose 7. Further, the length of the coil 21 may not be the same as the length from the suction port 11 of the water pump 2 to the cooling water outlet 4b of the radiator 4 as long as the rubber hose 7 can be prevented from being crushed. . Further, the helical angle of the coil 21 is appropriately set according to the performance and the rotational speed of the water pump 2 so that a swirling flow capable of improving the pump efficiency can be generated.

The coil 21 is not fixed to the casing 13 and the rubber hose 7 by welding or the like. However, since the outer diameter of the coil is larger than the inner diameter of the cylindrical portion constituting the suction port 11 of the casing 13, the positioning inside the rubber hose 7 is performed by hitting the suction port 11 of the casing 13. The coil 21 is press-fitted into the rubber hose 7 and is held by the rubber hose 7 by the elastic force of the rubber hose 7.

As shown in FIG. 2, the winding direction D1 of the coil 21 when viewed from the upstream side of the cooling water flow is opposite to the rotational direction D2 of the impeller 15. Specifically, when the impeller 15 and the coil 21 are viewed from the upstream side of the cooling water flow, the rotation direction D2 of the impeller 15 is counterclockwise (counterclockwise), whereas the winding direction D1 of the coil 21 is clockwise. Rotation (clockwise).

Next, the operation and effect of this embodiment will be described.

In the water pump 2, when the impeller 15 is rotationally driven by the electric motor 16, the cooling water is sucked into the casing 13 from the suction port 11, and the cooling water is sucked into the impeller 15 from a direction parallel to the rotation shaft 14. Cooling water is discharged from the impeller 15 in a direction orthogonal to the direction 14. At this time, the cooling water flows into the blade portion 15c of the impeller 15 and flows along the blade portion 15c, whereby the flow direction of the cooling water is changed. Then, the cooling water discharged from the impeller 15 passes through the scroll portion 17 and is discharged from the discharge port 12. Note that that the cooling water is sucked into the impeller 15 means that the cooling water flows between the blade portions 15c adjacent to each other in the rotation direction D2. The cooling water being discharged from the impeller 15 means that the cooling water is discharged from between the blade portions 15c adjacent to each other in the rotation direction D2.

The cooling water discharged from the discharge port 12 of the water pump 2 passes through the inside of the engine 3 to cool the engine 3 and is then radiated by the radiator 4. Then, the cooling water radiated by the radiator 4 flows through the rubber hose 7 and is sucked from the suction port 11 of the water pump 2.

At this time, in this embodiment, since the coil 21 is located inside the rubber hose 7, the cooling water flowing inside the rubber hose 7 flows along the coil 21. For this reason, a swirl flow swirling along the coil 21 is generated inside the rubber hose 7. In the present embodiment, since the winding direction D1 of the coil 21 is opposite to the rotation direction D2 of the impeller 15, the turning direction of the swirling flow is opposite to the rotation direction D2 of the impeller 15.

Here, in the prior art of Patent Document 1, in order to improve pump efficiency, a swirl flow swirling in the same direction as the impeller rotation direction is generated with respect to the cooling water sucked into the impeller. However, as can be seen from the experimental results shown in FIG. 3, the pump efficiency is also improved by generating a swirling flow swirling in the direction opposite to the rotation direction D <b> 2 of the impeller 15 with respect to the cooling water sucked into the impeller 15. Can be made.

In addition, FIG. 3 measured the pump efficiency by controlling the flow rate by changing the pipe resistance using a prototype of the water pump 2 having a rotation speed of 5000 rpm and a flow rate of about 200 L / min (pump output 500 W). It is an experimental result. In this experiment, the cooling water temperature was room temperature. The pump efficiency (%) on the vertical axis in FIG. 3 is calculated by the formula of pump efficiency (%) = water work (W) / power (W) × 100. Since the water pump 2 of the present embodiment is an electric type, the power (W) is a value calculated by the following formula: power (W) = input voltage (V) × drive power (A). Moreover, the pump output (W) on the horizontal axis in FIG. 3 is hydraulic work (W).

In Comparative Example 1 shown in FIG. 3, the coil 21 inside the rubber hose 7 is omitted from the cooling system 1 of the present embodiment. From FIG. 3, it can be seen that the pump efficiency of the present embodiment is higher than that of the comparative example in an operation region where the pump output is 400 W or higher. Therefore, as in the present embodiment, the cooling water is also drawn into the impeller 15 by generating a swirling flow swirling in the direction opposite to the rotation direction D2 of the impeller 15 with respect to the cooling water sucked into the impeller 15. When the direction is changed by flowing into the blade portion 15c and flowing along the blade portion 15c, it is presumed that a flow with less flow loss along the blade portion 15c can be made.

In addition, when the water pump 2 is operated at a high output, the pressure inside the pipe between the radiator 4 and the water pump 2 decreases. Therefore, unlike this embodiment, when the coil 21 is not inserted into the rubber hose 7 as in the comparative example 1, the strength of the rubber hose 7 becomes insufficient, and the rubber hose 7 is crushed. For this reason, there is a possibility that the effective cross-sectional area of the flow path of the cooling water becomes small and it becomes impossible to send out the coolant having a necessary flow rate. The phenomenon that the rubber hose 7 is crushed easily occurs when the temperature at which the saturated vapor pressure of the cooling water is lowered is high and when the rubber hose 7 is used at a high altitude where the atmospheric pressure is lowered.

In contrast, in the present embodiment, the rubber hose 7 is reinforced by the coil 21 disposed inside the rubber hose 7. Therefore, the rubber hose 7 can be prevented from being crushed due to a pressure drop on the suction port 11 side of the casing 13, and the effective flow area of the cooling water can be maintained at a required size.

By the way, as a method for preventing the rubber hose 7 from being crushed, a method of improving the strength of the rubber hose 7 by increasing the thickness of the rubber hose 7 or using a fibrous reinforcing material can be considered. However, in this case, the weight and cost increase. Furthermore, when the rubber hose 7 becomes thick due to thickening or the like, the radius of curvature R at the bent portion of the rubber hose 7 increases, so that the degree of freedom in layout when the rubber hose 7 is mounted on the vehicle may be reduced.

Also, as another method for preventing the rubber hose 7 from being crushed, it is conceivable to change the material of the piping to resin or metal. However, in this case, the rubber hose 7 (pipe) cannot be mounted on the vehicle while being bent and deformed, and the mountability may be deteriorated or the structure of the seal joint of the pipe connection portion may be complicated.

On the other hand, according to this embodiment, an existing general rubber hose can be adopted as the rubber hose 7. Thereby, since it is not necessary to change the structure and material of rubber hose 7 itself with respect to the existing rubber hose 7, the trouble by changing the structure and material of the above-mentioned rubber hose 7 itself can be avoided.

In the present embodiment, a configuration in which the coil 21 is disposed inside the rubber hose 7 is employed. Therefore, unlike the prior art of Patent Document 1, it is not necessary to provide a mechanism for generating a swirling flow in the casing, and the shape of the casing 13 can be simplified.

In the present embodiment, the coil 21 is simply inserted into the rubber hose 7, and the coil 21 can be easily assembled to the rubber hose 7.
(Second Embodiment)
The cooling system 1 of this embodiment is obtained by changing the coil 21 in the cooling system 1 of the first embodiment to a coil 22 shown in FIG. 4, and the other configuration is the same as that of the first embodiment.

As shown in FIG. 4, in the coil 22 of this embodiment, the winding direction D <b> 1 when viewed from the upstream side of the cooling water flow is the same direction as the rotational direction D <b> 2 of the impeller 15. Specifically, when the impeller 15 and the coil 22 are viewed from the upstream side of the cooling water flow, the winding direction D1 of the coil 22 and the rotation direction D2 of the impeller 15 are counterclockwise. For this reason, a swirl flow swirling in the same direction as the rotation direction D <b> 2 is generated inside the rubber hose 7.

Thereby, as can be seen from the experimental results shown in FIG. 3, the pump efficiency can be improved in the operation region where the pump output is large as compared with the comparative example 1 in which the swirl flow is not generated according to this embodiment. Can do.

As can be seen from the experimental results shown in FIG. 3, when the first embodiment and the second embodiment are compared, the pump efficiency of the first embodiment can be further improved. Therefore, in order to increase the pump efficiency, the winding direction D1 of the coil disposed inside the rubber hose 7 is preferably opposite to the rotation direction D2 of the impeller 15.
(Other embodiments)
The present disclosure is not limited to the above-described embodiment, and can be appropriately changed within a range not departing from the gist of the present disclosure, for example, as described below.

(1) In each embodiment described above, the

coils

21 and 22 are made of metal, but may be made of resin.

(2) In each of the above embodiments, the casing 13 of the water pump 2 is not provided with a mechanism for generating a swirling flow in the cooling water. However, in order to enhance the swirl flow, the casing 13 may be provided with a mechanism similar to that of the prior art.

(3) In each of the above-described embodiments, the cooling system 1 constitutes a cooling water circuit in which the cooling water circulates in the order of the water pump 2, the engine 3, and the radiator 4. However, a cooling water circuit in which cooling water circulates in the order of the water pump 2, the radiator 4, and the engine 3 may be configured.

(4) In each of the above-described embodiments, the cooling system 1 of the present disclosure is applied to a vehicle cooling system whose cooling target is the engine 3. However, the cooling target is not limited to the engine 3, and the cooling system 1 of the present disclosure can be applied to a cooling system that cools a heating element mounted on a vehicle. The heating element mounted on the vehicle is, for example, an inverter of an electric vehicle or a hybrid vehicle, a fuel cell of a fuel cell vehicle, or the like. The cooling system 1 of the present disclosure can also be applied to a cooling system that cools a heating element other than a heating element mounted on a vehicle.

(5) In each of the above-described embodiments, an ethylene glycol aqueous solution is used as the cooling water, but other aqueous solutions may be used, and a coolant other than the aqueous solution may be used.

(6) In each of the above-described embodiments, the centrifugal pump is employed as the water pump 2, but a mixed flow pump may be employed. In this case, in the casing, the cooling water is sucked into the impeller from a direction parallel to the rotation axis, and the cooling water is discharged from the impeller in a direction oblique to the rotation axis. In short, the present disclosure can employ a pump that discharges cooling water sucked into the impeller from the impeller in a direction intersecting the rotation axis. In addition, the flow direction of the cooling water sucked into the impeller may not be a direction parallel to the rotation axis, and may be a direction along the rotation axis.

(7) The above-described embodiments are not irrelevant to each other, and can be appropriately combined unless the combination is clearly impossible. In each of the above-described embodiments, it is needless to say that elements constituting the embodiment are not necessarily essential unless explicitly stated as essential and clearly considered essential in principle. Yes.

Claims

A casing (13) in which a suction port (11) for sucking cooling liquid and a discharge port (12) for discharging the cooling liquid are formed, and the casing (13) is housed in the casing and rotates together with the rotating shaft (14). A pump (2) having an impeller (15) for sucking the coolant and discharging the sucked coolant in a direction intersecting the rotation axis;
A rubber hose (7) connected to the inlet and through which the coolant flows;
A cooling system provided with the coil (21, 22) arrange | positioned inside the said rubber hose so that the inner peripheral surface of the said rubber hose may be touched and formed by winding a linear member helically.
The cooling system according to claim 1, wherein the coil (21) has a winding direction (D1) as viewed from an upstream side of a coolant flow direction opposite to a rotation direction (D2) of the impeller.
The pump and the rubber hose are mounted on a vehicle,
The cooling system according to claim 1 or 2, wherein the cooling liquid cools a heating element (3) mounted on the vehicle.