JP7327632B2 - Motor protection structure - Google Patents

Description

The present disclosure relates to a protective structure for an electric motor mounted on a vehicle.

As a related technique, various structures have been proposed for protecting a connector to which a power supply cable is connected in an electric motor mounted on a vehicle. For example, since there is a possibility that the electric motor may move due to an external force at the time of a vehicle collision and come into contact with other surrounding parts, it is being studied to improve the strength of the connector in advance. There is also a known structure in which a protrusion is formed near the connector of the electric motor so that the protrusion contacts other parts around the electric motor before the connector in the event of a vehicle collision (Japanese Patent Application Laid-Open No. 2019-2019). 099003, JP 2018-083510, and JP 2018-114899).

However, designing a reinforcing structure to improve the strength of the connector of the electric motor would increase the weight and complicate the structure, which would be disadvantageous in terms of manufacturing cost and productivity. The same is true when a protective member is arranged around the connector, and an increase in weight and complication of the structure cannot be avoided. In light of these circumstances, it is desirable to be able to effectively protect the connector of the electric motor with a simpler and easier configuration.

The electric motor protection structure according to the present disclosure is a simple structure and relates to improving the protection performance of the electric motor against external force.

According to one aspect of the present disclosure, an electric motor protection structure includes at least one electric motor mounted on a vehicle, a planar panel that partitions between the electric motor and a vehicle compartment, and a coolant that cools the electric motor. a cooling component including a heat exchanger configured to transfer heat to a medium other than the refrigerant, the cooling component being integrally secured to a surface of the motor facing the panel. be done.

FIG. 1 is a schematic diagram of a vehicle to which a motor protection structure as an embodiment is applied. 2 is a perspective view schematically showing the internal structure of the cooling component shown in FIG. 1. FIG. FIG. 3A is a schematic diagram for explaining the protective performance of the protective structure shown in FIG. 1 against external force. FIG. 3B is a schematic diagram for explaining the protective performance of the protective structure shown in FIG. 1 against external force. FIG. 3C is a schematic diagram for explaining the protective performance of the protective structure shown in FIG. 1 against external force. FIG. 4 is a schematic diagram of a vehicle to which a motor protection structure as a modification is applied.

[1. composition]
A motor protection structure as an embodiment and modifications will be described with reference to FIGS. 1 to 4. FIG. The arrows (front, rear, up, and down) indicating directions in the drawing mean directions determined with the vehicle 10 as a reference. FIG. 1 is a schematic side view showing through the inside of a vehicle 10 to which a motor protection structure is applied. An engine room 12 (also called a motor room or a compartment room) is provided in the front part of the vehicle 10, and a passenger compartment 11 is provided behind it. In the engine room 12, driving force generation devices such as the motor 1, the generator 2, and the engine 3 are arranged. These drive force generators are connected to each other so as to be able to transmit power to each other via a transmission and a transaxle (not shown).

The motor 1 is, for example, a three-phase AC synchronous motor, and has both a function of rotating a motor shaft (rotating shaft of a rotor) with the electric power of the battery 13 and a function of generating power using the inertial power of the vehicle 10. The generator 2 (generator) is, for example, a three-phase AC synchronous generator, and has a function (starter function) of rotating the crankshaft of the engine 3 with the electric power of the battery 13, and uses the rotational power of the crankshaft. It also has the function of generating power by The engine 3 is an internal combustion engine (gasoline engine, diesel engine) that burns gasoline or light oil.

Generally, a device that generates rotational force through the interaction of a current flowing through a rotor and a magnetic field is called an "electric motor". The motor 1 of this embodiment is an "electric motor". In addition, the generator 2 of this embodiment generates an induced current by rotating the rotor within the magnetic field, and it is possible to generate a rotational force by applying a current to the rotor. In other words, the generator 2 of this embodiment can function as an "electric motor" and can be regarded as a kind of "electric motor". In this sense, it is possible to define an “electric motor” as a concept that includes the motor 1 and the generator 2 . Therefore, the "electric motor" described in this specification may be described as "motor or generator or motor generator" and may be understood as such.

Motor 1 , generator 2 , and engine 3 are arranged so as to overlap each other when vehicle 10 is viewed from the front. For example, the generator 2 is arranged diagonally upward on the front side of the motor 1 . Further, the engine 3 is arranged in front of the generator 2 so as to cover the front surface of the generator 2 . In other words, the motor 1 and generator 2 are arranged behind the engine 3 . Further, a transmission and a transaxle (not shown) are arranged on one side of each of the motor 1, the generator 2, and the engine 3 in the vehicle width direction. Further, the respective rotating shafts (rotor shaft and crankshaft) of the motor 1, the generator 2, and the engine 3 are arranged parallel to each other in the vehicle width direction, for example.

A planar panel 4 partitions between the vehicle compartment 11 and the engine room 12 . The panel 4 is also called bulkhead or firewall. The panel 4 here includes a floor panel and a dash panel. As shown in FIG. 1 , the panel 4 is arranged substantially horizontally below the passenger compartment 11 and is formed in a shape that rises upward at the front part of the passenger compartment 11 . When forming the panel 4 having the shape shown in FIG. 1, it may be formed by bending a single plate material, or may be formed by connecting a plurality of plate materials.

A battery 13 and an inverter 14 are arranged below the compartment 11 (below the panel 4). The battery 13 is, for example, a lithium-ion battery or a nickel-metal hydride battery, and is a secondary battery capable of supplying a high-voltage DC current of several hundred volts. Battery 13 is electrically connected to motor 1 and generator 2 via inverter 14 . The battery 13 can supply electric power to the motor 1 and the generator 2 . In addition, the battery 13 can be charged with the regenerated power of the motor 1 or the generated power of the generator 2, and can also be charged by receiving power supply from the outside of the vehicle (external charging).

The inverter 14 is a power conversion device for converting DC power on the battery 13 side and AC power on the motor 1 and generator 2 sides, and is interposed on a power line connecting the battery 13, the motor 1 and the generator 2. . The inverter 14, also called a power drive unit (PDU), contains an inverter circuit and an electronic controller. The inverter circuit includes switch elements such as IGBTs (Insulated Gate Bipolar Transistors) and MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). Further, the electronic control unit has a function of controlling the operating state (on/off timing and drive frequency) of the switch element.

The inverter 14 and each of the motor 1 and the generator 2 are connected by a high voltage cable 15 for three-phase alternating current. The high-voltage cable 15 is connected to each of a first connector 16 provided on the outer surface of the motor 1 and a second connector 17 provided on the outer surface of the generator 2, as shown in FIG. The high voltage cable 15 is detachable from each of the first connector 16 and the second connector 17 . These first connector 16 and second connector 17 are preferably arranged in the vicinity of the cooling component 5 which will be described later. In this embodiment, the first connector 16 of the motor 1 to which the cooling component 5 is attached is positioned adjacent to the cooling component 5 .

A cooling component 5 is attached to the outer surface of the motor 1 . The cooling component 5 is a component including at least a heat exchanger 7 for cooling the motor 1 , and is fixed to one of the plurality of electric motors (motor 1 and generator 2 ) provided in the vehicle 10 . The heat exchanger 7 has a function of transferring the heat of the refrigerant that cools the motor 1 to another medium. The cooling component 5 is integrally fixed to the motor 1 on the side of the surface of the motor 1 facing the panel 4 . The cooling component 5 is provided with a first inlet and a first outlet serving as inlets and outlets for the coolant that cools the motor 1, and a second inlet and a second outlet serving as inlets and outlets for the medium for cooling the coolant. . Specific examples of the refrigerant or medium referred to here include cooling water, cooling oil, cold air, various coolants, and the like.

The cooling component 5 is fixed at a position where the separation distance between the cooling component 5 and the panel 4 is smaller than the separation distance between the motor 1 or the generator 2 and the panel 4 . More preferably, the cooling component 5 and the panel 4 are fixed at a position where the separation distance is smaller than the separation distance between the first connector 16 or the second connector 17 and the panel 4 . That is, even if the motor 1 or the generator 2 approaches the panel 4 due to an external force, the cooling component 5 is configured to contact the panel 4 before the first connector 16 or the second connector 17 . Further, the first connector 16 of this embodiment is arranged behind and below the cooling component 5, as shown in FIG. Thereby, the distance between the first connector 16 and the inverter 14 can be shortened while the first connector 16 is separated from the panel 4 more than the cooling component 5 . Therefore, the high-voltage cable 15 can be shortened while enhancing the protection of the first connector 16 .

A specific example of the cooling component 5 is shown in FIG. This cooling component 5 has a structure in which a laminated heat exchanger 7 is built in a hollow casing 6 . The heat exchanger 7 has a structure in which a plurality of plates 8 are stacked in multiple layers with a gap between them. Also, corrugated fins 9 are provided between the plurality of plates 8 . The corrugated fin 9 is a plate-like member having a corrugated cross section so as to come into contact with each of the two plates 8 . By providing the corrugated fins 9, heat transfer between the plurality of plates 8 is promoted, and heat exchange efficiency is improved.

Inside the heat exchanger 7, as shown in FIG. 2, layers through which a refrigerant (for example, cooling oil) that cools the motor 1 flows and layers through which a medium that cools the refrigerant (for example, engine cooling water) flow alternately. is laminated to These refrigerants and mediums flow through the groove-like space sandwiched between the plate 8 and the corrugated fins 9 . Also, the direction of circulation of the coolant flowing through the former layer is set to be orthogonal to the direction of circulation of the medium flowing through the latter layer. By making the flow directions in each layer orthogonal, it is possible to easily form a structure in which the coolant and medium do not mix with each other.

The stacking direction of the plurality of plates 8 is set to match the direction from the motor 1 toward the panel 4 as shown in FIG. The lamination direction referred to here may be understood by reading, for example, the normal direction of the plate 8 . Alternatively, the direction perpendicular to the circulation direction of the coolant and medium flowing through each layer may be defined as the "stacking direction". With such a layout, for example, when an external force acts on the heat exchanger 7 of the cooling component 5, the impact is absorbed by deformation of the plate 8 in the thickness direction, and the cooling component 5 functions as a cushioning member.

As shown in FIG. 1 , the cooling component 5 is arranged on the surface of the panel 4 at a position facing a slope whose front is inclined upward (that is, the plate 8 of the heat exchanger 7 faces the slope of the panel 4 ). ). This slope is provided, for example, at the front end of the floor panel or the lower end of the dash panel. By facing the cooling component 5 to the inclined surface, the reaction force when the cooling component 5 comes into contact with the panel 4 can act diagonally forward and downward. Therefore, it becomes easier to secure a space in the passenger compartment 11, and the occupant protection performance is improved.

The cooling component 5 is arranged at a position facing the flat portion 18 of the panel 4 . The planar portion 18 is a portion formed in a planar shape, and is provided substantially parallel to the plate 8 positioned closest to the panel 4 among the plates 8 of the heat exchanger 7 . As shown in FIG. 1, by arranging the cooling component 5 on a planar portion, the contact area when the cooling component 5 contacts the panel 4 increases, and the pressure acting on the cooling component 5 decreases. This makes it easier to absorb the impact, and improves the cushioning performance of the cooling component 5 .

[2. action, effect]
As shown in FIG. 3A , when an external force (indicated by a black arrow in the drawing) acts from the front of the vehicle 10 , the engine 3 may be pushed rearward of the vehicle 10 inside the engine room 12 . In this case, the engine 3 contacts the generator 2 and pushes the generator 2 backward, and the motor 1 and the generator 2 move toward the panel 4 . The separation distance between the motor 1 and generator 2 and the panel 4 gradually decreases.

On the other hand, a cooling component 5 is attached to the outer surface of the motor 1 . The cooling component 5 is arranged at a position where it comes into contact with the panel 4 before the motor 1 and the generator 2 do. Therefore, as shown in FIG. 3B, when the cooling component 5 contacts the panel 4, the separation distance between the motor 1 and the generator 2 and the panel 4 is ensured, and direct contact is avoided. Also, the cooling component 5 is arranged at a position where it comes into contact with the panel 4 before the first connector 16 and the second connector 17 do. Therefore, when the cooling component 5 contacts the panel 4, the separation distance between the first connector 16 and the second connector 17 and the panel 4 is also ensured.

As the motor 1 and generator 2 move further toward the panel 4, the cooling component 5 sandwiched between the panel 4 and the motor 1 is compressed and deformed, as shown in FIG. 3C. The energy of the external force is absorbed in the process of this compressive deformation. This prevents contact between the motor 1, the generator 2, the first connector 16, the second connector 17, and the panel 4, and suppresses deformation and damage. Note that the distance from the inverter 14 to the first connector 16 changes as the motor 1 moves. However, if the high-voltage cable 15 connecting between the inverter 14 and the first connector 16 has flexibility, such deformation is reasonably allowed.

(1) The electric motor protection structure of this embodiment includes the motor 1 mounted on the vehicle 10, the panel 4, and the cooling component 5. FIG. The panel 4 is provided so as to partition the motor 1 and the vehicle compartment 11 . The cooling component 5 is integrally fixed to the side of the surface of the motor 1 facing the panel 4 . The cooling component 5 also includes a heat exchanger 7 that transfers the heat of the refrigerant that cools the motor 1 to another medium. With such a configuration, deformation and damage of the motor 1 due to contact between the motor 1 and the panel 4 can be suppressed. Moreover, there is no need to add a protective member or a reinforcing structure between the motor 1 and the panel 4, and an increase in weight and complication of the structure can be avoided. Therefore, it is possible to improve the protection performance of the electric motor (motor 1 and generator 2) with a simple structure.

(2) As shown in FIG. 1 , the motor 1 is arranged behind the engine 3 mounted on the vehicle 10 . As a result, deformation and damage to the motor 1 due to contact between the panel 4 and the motor 1 pushed by the engine 3 when the vehicle 10 collides can be suppressed. Incidentally, in the vehicle 10 in which the engine 3 is not mounted, it is possible to arrange some cushioning member (crash box, cushion member, etc.) at the position of the engine 3 in FIG. On the other hand, in the vehicle 10 in which the engine 3 is mounted, there are cases where there is no spatial margin for arranging such a buffer member. On the other hand, according to the above protection structure, there is an advantage that the protection performance of the motor 1 can be improved without arranging such a buffer member.

(3) The heat exchanger 7 has a structure in which a plurality of plates 8 are laminated with gaps between them. These plates 8 are stacked in the direction from the motor 1 to the panel 4, as shown in FIG. Since the stacking direction of the heat exchangers 7 corresponds to the direction from the motor 1 toward the panel 4, the impact can be absorbed by the deformation of the plate 8 in the thickness direction, and the cushioning function of the cooling component 5 can be improved. can. In addition, since there are gaps between the plurality of plates 8 through which the coolant flows, a deformation margin (maximum amount of deformation) of the plates 8 can be ensured, and impact absorption efficiency can be enhanced. Therefore, it is possible to improve the protection performance of the electric motor (motor 1 and generator 2).

(4) The first connector 16 of the motor 1 is positioned adjacent to the cooling component 5 as shown in FIG. Such a layout allows the cooling component 5 to contact the panel 4 at least before the first connector 16 when the motor 1 and generator 2 are moved towards the panel 4 . Therefore, the first connector 16 can be protected more reliably, and the protection performance of the electric motor (motor 1 and generator 2) can be improved.

(5) As shown in FIG. 1 , the first connector 16 is arranged behind the vehicle 10 relative to the cooling component 5 . As a result, in a layout in which the battery 13 and the inverter 14 are arranged behind the motor 1, the distance between the first connector 16 and the inverter 14 is increased while the first connector 16 is separated from the panel 4 more than the cooling component 5. can get closer. Therefore, the high-voltage cable 15 can be shortened while protecting the first connector 16, thereby further simplifying the configuration of the electric motor (motor 1 and generator 2).

(6) The cooling component 5 is arranged on the surface of the panel 4 at a position facing a slope whose front is inclined upward. In this way, by inclining the panel 4 at the location facing the cooling component 5, the reaction force when the cooling component 5 contacts the panel 4 can act obliquely forward and downward. In other words, when the motor 1 and the generator 2 move toward the interior of the vehicle compartment 11, the amount of horizontal movement of the motor 1 and the generator 2 can be reduced. Therefore, it is possible to secure the space of the passenger compartment 11 and improve the occupant protection performance.

(7) The cooling component 5 is fixed to the motor 1, which is one of a plurality of electric motors provided in the vehicle. The position where the cooling component 5 is fixed is set at a position where the separation distance between the cooling component 5 and the panel 4 is smaller than the separation distance between the motor 1 or the generator 2 and the panel 4 . In other words, the fixing position of the cooling component 5 is determined so that the cooling component 5 is positioned closer to the panel 4 than the motor 1 and the generator 2 when the cooling component 5 is attached. With such a layout, when the motor 1 and the generator 2 move toward the panel 4, the cooling component 5 can be brought into contact with the panel 4 before the motor 1 and the generator 2 do. Therefore, the motor 1 and the generator 2 can be reliably protected, and the protection performance of the electric motor (the motor 1 and the generator 2) can be improved.

(8) As shown in FIG. 1 , the cooling component 5 is arranged at a position facing the flat portion 18 of the panel 4 . As a result, when the motor 1 and the generator 2 move toward the panel 4, the end surface of the cooling component 5 near the panel 4 can be brought into surface contact with the panel 4, and the contact area between the cooling component 5 and the panel 4 can be reduced to can be increased. In other words, the pressure acting on the cooling component 5 can be reduced, and the shock can be absorbed while compressively deforming the entire cooling component 5 evenly. Therefore, the cushioning performance of the cooling component 5 can be improved.

[3. Modification]
The above embodiment is merely an example, and is not intended to exclude various modifications and application of techniques not explicitly described in this embodiment. Each configuration of this embodiment can be modified in various ways without departing from the gist thereof. Also, they can be selected or combined as needed. For example, in the above embodiment, the hybrid vehicle in which the motor 1, the generator 2, and the engine 3 are arranged inside the engine room 12 was exemplified, but the above protection structure is applied to an electric vehicle that does not have the generator 2 or the engine 3. It is also possible to

In the above embodiment, the cooling component 5 is fixed to the surface of the motor 1 at a position facing the flat portion 18 of the panel 4, but the positional relationship between the cooling component 5 and the panel 4 is such a relationship. Not limited. For example, as shown in FIG. 4 , the cooling component 5 may be arranged at a position facing the bent portion 19 of the panel 4 . The bent portion 19 is a portion having a shape in which two surfaces are joined with a ridgeline interposed therebetween, and is formed by bending a planar member, for example. By providing the cooling component 5 so as to face the bent portion 19, interference between the bent portion 19 and the motor 1 is prevented. Therefore, it is possible to improve the protection performance of the electric motor (motor 1 and generator 2).

This application is based on Japanese Patent Application No. 2020-022503 filed on February 13, 2020, the contents of which are incorporated herein by reference.

1 motor (electric motor, driving device)
2 Generator (motor, driving device)
3 Engine (internal combustion engine, drive system)
4 Panel 5 Cooling component 6 Casing 7 Heat exchanger 8 Plate 9 Corrugated fin 10 Vehicle 11 Vehicle compartment 12 Engine room 13 Battery 14 Inverter 15 High voltage cable 16 First connector 17 Second connector 18 Flat part 19 Bending part

Claims (7)

at least one electric motor mounted on the vehicle;
a planar panel that partitions between the electric motor and the vehicle compartment;
a heat exchanger configured to transfer heat of a refrigerant that cools the electric motor to a medium different from the refrigerant;
The heat exchanger has a structure in which a plurality of plates are stacked with a gap between each other,
integrally fixed to the side of the surface of the electric motor facing the panel , in a laminated state such that the stacking direction of the plurality of plates coincides with the direction from the electric motor to the panel;
The at least one electric motor includes a plurality of electric motors mounted on the vehicle,
The heat exchanger is fixed to one of the plurality of electric motors, and a separation between a plate of the plurality of plates of the heat exchanger located closest to the panel and the panel. A protective structure for an electric motor, wherein the motors are fixed so that a distance between them is smaller than a separation distance between each of the plurality of electric motors and the panel. 2. A protection structure for an electric motor according to claim 1, wherein said electric motor is arranged behind an engine mounted on said vehicle. 3. The electric motor according to claim 1 , further comprising a connector arranged adjacent to the heat exchanger on the surface of the electric motor and connected to a battery mounted on the vehicle via a cable. motor protection structure. 4. A protective structure for an electric motor according to claim 3 , wherein said connector is arranged behind said heat exchanger . The panel includes a slope that slopes obliquely upward on the front side of the vehicle,
A protective structure for an electric motor according to any one of claims 1 to 4 , wherein said heat exchanger is arranged to face said inclined surface. The panel has a planar portion that is a flat surface,
The protection structure for an electric motor according to any one of claims 1 to 5 , wherein the heat exchanger is arranged so as to face the flat portion of the panel. The panel has a bent portion that is a bent surface,
A protective structure for an electric motor according to any one of claims 1 to 5 , characterized in that said heat exchanger is arranged so as to face said bent portion of said panel.

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