Electric pump

Abstract

To simplify a cooling circuit of an electric vehicle.SOLUTION: An electric pump 1 is provided in a cooling circuit in which a cooling medium circulates in an electric vehicle. The electric pump 1 includes an inlet port 6 for taking in the cooling medium, and a plurality of outlet ports 7 for discharging the cooling medium. The outlet ports 7 have inside diameters different from each other. The electric pump 1 has the plurality of outlet ports 7, and therefore, a flow passage of the cooling circuit is branched into a plurality of flow passages on a downstream side of the electric pump 1. The outlet ports 7 have the inside diameters different from each other, and therefore, a flow rate of the cooling medium can be optimized in each of the flow passages on the downstream side of the electric pump 1.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an electric pump provided in a cooling circuit through which a cooling medium circulates in an electric vehicle. [Background technology]

[0002] Conventionally, vehicles are provided with pumps for circulating a cooling medium for cooling various devices in a cooling circuit. For example, Patent Document 1 discloses an oil pump that supplies oil as a cooling medium to a cooling circuit connected to a motor of an electric vehicle. In the technology described in Patent Document 1, the oil discharged from the oil pump is guided to a torque transmission means and a motor through a lubrication circuit and a cooling circuit that branch off from the discharge circuit. In addition, each of the lubrication circuit and the cooling circuit is provided with an orifice as a throttling means. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 8-98464 Summary of the Invention [Problem to be solved by the invention]

[0004] When the cooling medium discharged from the pump is guided to a plurality of branched flow paths as described in Patent Document 1, components for branching the flow paths (for example, a bifurcated joint or a trifurcated joint) are required, resulting in an increase in the number of parts. Also, as described in Patent Document 1, the flow rate of the cooling medium needs to be adjusted depending on the supply destination of the cooling medium, so an orifice is also required to narrow the flow path area, resulting in a further increase in the number of parts.

[0005] In particular, in electric vehicles (electric cars, hybrid cars), various devices including high-voltage batteries, motors, and inverters are to be cooled. For this reason, electric vehicles may be required to connect some of the cooling circuits in parallel or adjust the flow rate of the cooling medium according to the individual cooling objects. As a result, there are issues that the number of parts tends to increase and the cooling circuits tend to become complicated.

[0006] The present invention has been devised in view of the above-mentioned problems, and one of its objects is to simplify the cooling circuit of an electric vehicle. [Means for solving the problem]

[0007] The present invention has been made to solve at least part of the above problems, and can be realized in the following aspects or application examples. The electric pump of this application example is an electric pump provided in a cooling circuit in an electric vehicle through which a cooling medium circulates, and includes an inlet port that takes in the cooling medium, and a plurality of outlet ports that have different inner diameters and discharge the cooling medium.

[0008] According to this application example, since the electric pump has a plurality of outlet ports, the flow path of the cooling circuit can be branched into a plurality of paths downstream of the electric pump. This makes it possible to form parallel flow paths in the cooling circuit without providing a separate part (for example, a bifurcated joint or a trifurcated joint) for branching the flow path.

[0009] In addition, since the multiple outlet ports have different inner diameters, the flow rate of the cooling medium can be adjusted in each flow path downstream of the electric pump, making it possible to optimize the flow rate of the cooling medium in each flow path of the cooling circuit without providing a separate structure for adjusting the flow rate (e.g., an orifice).

[0010] Therefore, according to this application example, since the electric pump itself has both the function of branching the flow path and the function of adjusting the flow rate of the cooling medium, it is possible to omit components for branching the flow path and a structure for adjusting the flow rate of the cooling medium from the cooling circuit, thereby reducing the number of components in the cooling circuit and simplifying the cooling circuit of the electric vehicle. Effect of the Invention

[0011] According to the present invention, the cooling circuit of the electric vehicle can be simplified. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing a cooling circuit of an electric vehicle provided with an electric pump according to an application example. [Diagram 2] FIG. 2 is a front view of the electric pump (first pump) in FIG. [Diagram 3] 3 is a schematic diagram showing an arrangement of a plurality of outlet ports provided in the electric pump (first pump) in FIG. 2. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The following describes the embodiments (application examples) of the present invention with reference to the drawings. The following embodiments are merely examples, and are not intended to exclude various modifications or applications of techniques not clearly stated in the embodiments. The configurations of the following embodiments can be modified in various ways without departing from the spirit of the embodiments. They can also be selected or combined as necessary.

[0014] [1. Configuration] [1-1. Cooling circuit] 1, an electric pump 1 according to this embodiment (application example) is provided in a cooling circuit 3 through which a cooling medium circulates in an electric vehicle 2. The electric vehicle 2 is an electric car that includes a high-voltage battery 4 (HV BATT) that stores electric power, and a motor 5 (MOTOR) to which electric power is supplied from the high-voltage battery 4, and runs on the power of the motor 5.

[0015] The electric vehicle 2 may be a hybrid vehicle equipped with an engine (internal combustion engine) in addition to the motor 5. In this embodiment, the electric vehicle 2 is a small truck, but the electric vehicle 2 is not limited to this and may be, for example, a large truck, a bus, or a passenger car. Although one high-voltage battery 4 is illustrated in FIG. 1, the electric vehicle 2 may be equipped with multiple high-voltage batteries 4.

[0016] The cooling circuit 3 is a flow path of a cooling medium provided to cool various devices mounted on the electric vehicle 2. Here, a water-cooled cooling circuit 3 using cooling water (antifreeze) as the cooling medium is illustrated. The cooling circuit 3 of this embodiment is provided with a first circuit 3A (see solid line in FIG. 1) for mainly cooling the high-voltage battery 4, and a second circuit 3B (see dashed line in FIG. 1) for mainly cooling the motor 5. In this embodiment, a first pump 1A provided in the first circuit 3A and a second pump 1B provided in the second circuit 3B are illustrated as the electric pump 1.

[0017] In addition to the first pump 1A and the high-voltage battery 4, the first circuit 3A is provided with a DC / DC converter 21 (DC / DC), an on-board charger 22 (OBC), a heater 23 (HEATER), a first radiator 24 (1st RAD), and a chiller 25 (CHILLER). The high-voltage battery 4, the DC / DC converter 21, and the on-board charger 22 are all devices (cooling targets) that are cooled by the cooling medium flowing through the first circuit 3A. Note that the high-voltage battery 4 and the DC / DC converter 21 are devices that are not installed in a normal engine vehicle, and are cooling targets unique to the electric vehicle 2.

[0018] On the other hand, the heater 23 is used to heat the cooling medium when, for example, temperature control of the high-voltage battery 4 is required in an extremely cold environment. The first radiator 24 and the chiller 25 are used to cool the cooling medium. More specifically, the first radiator 24 removes heat from the cooling medium by blowing air from the fan 30. The chiller 25 is, for example, an evaporator, and removes heat from the cooling medium by evaporating the cooling medium.

[0019] In the first circuit 3A, a first main flow path 31 and a first sub-flow path 32, which are parallel to each other, are connected to the downstream side of the first pump 1A (an outlet port 7 described later). A heater 23 and a high-voltage battery 4 are arranged in series in this order from the upstream side on the first main flow path 31. In addition, a DC / DC converter 21 and an on-board charger 22 are arranged in series in this order from the upstream side on the first sub-flow path 32.

[0020] At least one of the maximum allowable temperature and maximum flow rate of the cooling medium is different between the high-voltage battery 4 on the first main flow path 31 and the DC / DC converter 21 on the first sub-flow path 32. Therefore, the first main flow path 31 and the first sub-flow path 32 have different cooling performances required of the cooling medium, i.e., suitable flow rates of the cooling medium.

[0021] The first main flow path 31 and the first sub-flow path 32 merge into a common downstream flow path 33. The downstream flow path 33 is connected to a radiator flow path 34 and a chiller flow path 35, which are parallel to each other, via a three-way valve 26. The first radiator 24 is disposed on the radiator flow path 34, and the chiller 25 is disposed on the chiller flow path 35. The radiator flow path 34 and the chiller flow path 35 merge into a common upstream flow path 36. The upstream flow path 36 is connected to the upstream side of the first pump 1A (an inlet port 6, which will be described later).

[0022] In addition to the second pump 1B and the motor 5, the second circuit 3B is provided with an inverter 27 (INV), an auxiliary inverter 28 (ePTO INV), and a second radiator 29 (2nd RAD). The motor 5, the inverter 27, and the auxiliary inverter 28 are all devices (subjects to be cooled) that are cooled by the cooling medium flowing through the second circuit 3B. In this embodiment, the motor 5 and the inverter 27 are illustrated as an integral unit. Note that the motor 5, the inverter 27, and the auxiliary inverter 28 are devices that are not installed in a normal engine vehicle, and are subjects to be cooled that are specific to the electric vehicle 2.

[0023] The auxiliary inverter 28 is an inverter for an electric auxiliary (so-called ePTO: Electric Power Take Off) mounted on the electric vehicle 2. The auxiliary inverter 28 may be, for example, an inverter for an AC compressor mounted on a refrigerated vehicle, an inverter for driving a vessel mounted on a dump truck, or an inverter for a motor that drives a mechanism for loading dust in a garbage truck.

[0024] The second radiator 29 is used to cool the cooling medium in the same manner as the first radiator 24. Specifically, the second radiator 29 is arranged alongside the first radiator 24, and removes heat from the cooling medium by air blown from the fan 30 in the same manner as the first radiator 24.

[0025] In the second circuit 3B, a second main flow path 41, a second sub-flow path 42, and a bypass flow path 43 are connected in parallel to one another to the downstream side (outlet port 7) of the second pump 1B. A unitized motor 5 and an inverter 27 are arranged on the second main flow path 41, and an auxiliary inverter 28 is arranged on the second sub-flow path 42. On the other hand, nothing is arranged on the bypass flow path 43. The bypass flow path 43 can be said to be a flow path that bypasses the motor 5, the inverter 27, and the auxiliary inverter 28.

[0026] At least one of the maximum allowable temperature and maximum flow rate of the cooling medium is different between the motor 5 and the inverter 27 in the second main flow path 41 and the auxiliary inverter 28 in the second sub flow path 42. Therefore, the cooling performance required of the cooling medium, i.e., the suitable flow rate of the cooling medium, is different between the second main flow path 41 and the second sub flow path 42. In the present embodiment, the suitable flow rate of the cooling medium is also different between the second main flow path 41 and the second sub flow path 42 in the bypass flow path 43.

[0027] The second main flow path 41, the second sub-flow path 42, and the bypass flow path 43 merge into a common connecting flow path 44. The second radiator 29 is disposed on the connecting flow path 44. The connecting flow path 44 is connected to the upstream side (inlet port 6) of the second pump 1B. Note that the flow paths 31-36, 41-44 in the cooling circuit 3 are all formed of a member (e.g., piping) through which the cooling medium can flow. In addition, a reserve tank and a condenser tank (both not shown) for temporarily storing the cooling medium are connected to each of the first circuit 3A and the second circuit 3B.

[0028] [1-2. Electric pump] The first pump 1A and the second pump 1B have a common feature except that they have different numbers of outlet ports 7. In this embodiment, the first pump 1A will be described as an example, and a detailed description of the second pump 1B will be omitted. Figures 2 and 3 show the first pump 1A as an example of the electric pump 1.

[0029] 2, the electric pump 1 has an inlet port 6 that takes in the cooling medium and multiple outlet ports 7 that discharge the cooling medium. In this way, the electric pump 1 has only one inlet port 6, but at least two outlet ports 7. This allows the electric pump 1 to have a function of branching the flow path into multiple branches.

[0030] Each of the inlet port 6 and the outlet port 7 is formed in the shape of a pipe having a hollow portion through which a cooling medium can flow. Each of the inlet port 6 and the outlet port 7 is connected to a pipe that forms a flow path of the cooling circuit 3. The pipe connected to each outlet port 7 usually has a shape and size based on a predetermined standard.

[0031] The inlet port 6 is formed on the shaft 10 in the main body 8 of the electric pump 1. The inlet port 6 takes in a cooling medium into the inside of the main body 8 along the extending direction of the shaft 10 (the direction perpendicular to the plane of FIG. 2) by the rotation of a rotor (not shown) attached to the shaft 10 inside the main body 8. On the other hand, each outlet port 7 is formed along a tangent line 11 of a virtual circle (not shown) centered on the shaft 10. Each outlet port 7 discharges the cooling medium sucked in from the inlet port 6 from the inside of the main body 8 along the extending direction of the tangent line 11 (the direction parallel to the plane of FIG. 2).

[0032] The plurality of outlet ports 7 have different circumferential positions centered on the shaft 10. FIG. 2 illustrates two outlet ports 7 arranged point-symmetrically about the shaft 10. That is, in the first pump 1A of the present embodiment, the two outlet ports 7 are arranged such that when one outlet port 7 is virtually rotated 180° around the shaft 10, it exactly overlaps with the other outlet port 7. Such outlet ports 7 can be said to be arranged rotationally symmetrically about the shaft 10, and can also be said to be arranged at equal intervals in the circumferential direction.

[0033] As shown in FIG. 3, the plurality of outlet ports 7 provided in the electric pump 1 have different inner diameters. Thereby, the electric pump 1 has a function of adjusting the flow rate of the cooling medium in each branched flow path. Here, of the two outlet ports 7 provided in the first pump 1A, one (the left side in FIG. 3) is also referred to as the "first outlet port 7A", and the other (the right side in FIG. 3) is also referred to as the "second outlet port 7B". In the present embodiment, a case where the inner diameter d1 of the first outlet port 7A is larger than the inner diameter d2 of the second outlet port 7B (d2 < d1) is illustrated.

[0034] As described above, the multiple outlet ports 7 provided in the electric pump 1 have different inner diameters, but all have the same outer diameter. That is, as shown in Fig. 3, the outer diameter D1 of the first outlet port 7A and the outer diameter D2 of the second outlet port 7B are equal to each other (D1 = D2).

[0035] Therefore, the outlet ports 7 have the same outer diameter, but the wall thicknesses of the ports are different from one another, and therefore the inner diameters are different from one another. Specifically, the wall thickness t1 of the first outlet port 7A (half the difference between the outer diameter D1 and the inner diameter d1 [(D1-d1) / 2]) is smaller than the wall thickness t2 of the second outlet port 7B (half the difference between the outer diameter D2 and the inner diameter d2 [(D2-d2) / 2]) (t1 <t2)。

[0036] Although not shown in the drawings, the second pump 1B differs from the first pump 1A which has two outlet ports 7 in that the second pump 1B has three outlet ports 7. The three outlet ports 7 in the second pump 1B are arranged, for example, rotationally symmetrically about the axis 10 (at intervals of 120° around the axis 10). Note that in the second pump 1B as well, the three outlet ports 7 have different inner diameters and wall thicknesses but the same outer diameters.

[0037] [2. Actions and Effects] As described above, the electric vehicle 2 is equipped with specific objects to be cooled, such as the high-voltage battery 4, the DC / DC converter 21, the motor 5, the inverter 27, and the auxiliary inverter 28. As described above, the electric vehicle 2 has a larger number of devices to be cooled than an engine vehicle, and therefore it may be necessary to arrange some of the cooling circuits 3 in parallel or adjust the flow rate of the cooling medium according to each object to be cooled. As a result, for example, if a two-way or three-way joint is provided or an orifice 9 shown by a two-dot chain line in Fig. 1 is provided, the number of parts increases, which is a problem in that the cooling circuit 3 is likely to become complicated.

[0038] To address this issue, the electric pump 1 has a plurality of outlet ports 7, so that the flow path of the cooling circuit 3 can be branched into a plurality of paths downstream of the electric pump 1. This allows parallel flow paths to be formed in the cooling circuit 3 without the need for additional components (such as a bifurcated joint or a trifurcated joint) for branching the flow path. In this embodiment, the first pump 1A having two outlet ports 7 allows the flow path to be branched into the first main flow path 31 and the first sub-flow path 32 without the need for additional components for branching the flow path. Similarly, the second pump 1B having three outlet ports 7 allows the flow path to be branched into the second main flow path 41, the second sub-flow path 42, and the bypass flow path 43 without the need for additional components for branching the flow path.

[0039] In addition, in the electric pump 1, since the outlet ports 7 have different inner diameters, the flow rate of the cooling medium can be adjusted in each flow path downstream of the electric pump 1. This allows the flow rate of the cooling medium to be optimized in each flow path of the cooling circuit 3 without providing a separate structure (e.g., an orifice) for adjusting the flow rate. Therefore, in this embodiment, a suitable flow rate of the cooling medium can be realized in each of the first main flow path 31 and the first sub-flow path 32 downstream of the first pump 1A. Similarly, a suitable flow rate of the cooling medium can be realized in each of the second main flow path 41, the second sub-flow path 42, and the bypass flow path 43 downstream of the second pump 1B.

[0040] Therefore, according to the above electric pump 1, the electric pump 1 itself has both the function of branching the flow path and the function of adjusting the flow rate of the cooling medium, so that parts for branching the flow path and a structure for adjusting the flow rate of the cooling medium can be omitted from the cooling circuit 3. This reduces the number of parts in the cooling circuit 3, and therefore the cooling circuit 3 of the electric vehicle 2 can be simplified.

[0041] If the multiple outlet ports 7 in the electric pump 1 are arranged symmetrically, it becomes easier to adjust the balance of the flow rates of the cooling medium discharged from the multiple outlet ports 7. Therefore, the desired flow rate of the cooling medium can be more appropriately discharged from the multiple outlet ports 7. Furthermore, if all of the multiple outlet ports 7 are formed along the above-mentioned tangent line 11, the discharge of the cooling medium from each outlet port 7 can be made smoother.

[0042] If the outer diameters of the multiple outlet ports 7 in the electric pump 1 are equal to each other, all of the multiple outlet ports 7 can be made to conform to a predetermined standard. Therefore, while the flow rate adjustment function is achieved by the configuration in which the inner diameters of the outlet ports 7 are different from each other as described above, general-purpose piping that conforms to a predetermined standard can be connected to each outlet port 7. This increases the versatility of the electric pump 1.

[0043] [3.Other] The specific configuration of the electric pump 1 is not limited to the above example as long as it has at least one inlet port 6 and at least two outlet ports 7. For example, the electric pump 1 may be formed with four outlet ports 7, so that the flow path of the cooling medium is branched into four on the downstream side of the electric pump 1.

[0044] The arrangement of the outlet ports 7 in the electric pump 1 is not limited to the above example. The outlet ports 7 may be arranged asymmetrically. The outlet ports 7 may at least have different inner diameters. For example, the outlet ports 7 may have the same wall thickness or different outer diameters.

[0045] Furthermore, for example, the inner diameters of the multiple outlet ports 7 may be made different from one another by fitting a hollow member such as a collar into the outlet port 7. Alternatively, the inner diameters of the multiple outlet ports 7 may be made different from one another by providing a valve in the outlet port 7 and adjusting the opening of the valve as appropriate. Note that in this specification, the "different inner diameters" of the outlet ports 7 also includes a configuration in which the amount of cooling medium discharged from each outlet port 7 is made different from one another by adjusting the opening of the valve.

[0046] The above-described configuration of the cooling circuit 3 is also one example. The electric pump 1 is applicable to various cooling circuits in which a cooling medium circulates in the electric vehicle 2. For example, the electric pump 1 may be provided in only one of the first circuit 3A and the second circuit 3B, or may be provided in a cooling circuit other than the first circuit 3A and the second circuit 3B. [Explanation of symbols]

[0047] 1 Electric pump 1A First Pump 1B Second pump 2. Electric vehicles 3 Cooling circuit 3A first circuit 3B Second circuit 4 High Voltage Battery 5 Motor 6 Inlet Port 7 Outlet Port 7A First Outlet Port 7B Second outlet port 8 Main body 9 Orifice 10 Axis 11 tangent 21 DC / DC converter 22 On-board charger 23 Heater 24 First radiator 25 Chiller 26 Three-way valve 27 Inverter 28 Auxiliary inverter 29 Second radiator 30 Fans 31 Primary channel 32 First secondary channel 33 Downstream passage 34 Radiator passage 35 Chiller flow path 41 Second main channel 42 Second Sub-channel 43 Bypass flow path 44 Connecting Channel D1 Outer diameter of first outlet port 7A d1 Inner diameter of first outlet port 7A D2 Outside diameter of second outlet port 7B d2 Inner diameter of second outlet port 7B t1 Wall thickness of first outlet port 7A t2 Wall thickness of second outlet port 7B

Claims

[Claim 1] An electric pump provided in a cooling circuit through which a cooling medium circulates in an electric vehicle, an inlet port for taking in the cooling medium; a plurality of outlet ports having different inner diameters and discharging the cooling medium; An electric pump.

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