Body structure of a hybrid vehicle

Abstract

A body structure of a hybrid vehicle (10) driven using power from an internal combustion engine (11) and power from a drive motor driven by electric power supplied from a battery, the body structure comprising: a propeller shaft (13) arranged under a floor plate (14) relative to the vertical direction of the vehicle (10) so as to extend in a front-rear direction of the hybrid vehicle (10) and configured to transmit the power of the internal combustion engine (11) and the power of the drive motor to at least one rear wheel; and an integrated battery unit (15) arranged under the floor plate (14) in such a way that it covers the cardan shaft (13) viewed from below in the vertical direction of the vehicle, the integrated battery unit (15) comprising at least the rechargeable battery, wherein the battery unit (15) has a recess (26) for receiving the cardan shaft (13).

Description

The present application claims priority to Japanese Patent Application JP 2013-112 182 A, the contents of which are incorporated herein by reference in its entirety.The present invention relates to a body structure of a hybrid vehicle, and more particularly to a body structure of a hybrid vehicle in which a battery unit is disposed outside the passenger compartment of the vehicle.A body structure of a hybrid vehicle is generally known in which a battery unit is disposed behind the rear seats. The body structure of a hybrid vehicle requires a shield member that prevents heat radiated from the battery unit from being transferred to the rear seats.The need for a shield member may increase the manufacturing cost of the body structure of a hybrid vehicle. In addition, the body structure of such a hybrid vehicle may cause the temperature in the passenger compartment of the vehicle to increase due to the heat radiated from the battery unit.Therefore, in recent years, a demand has arisen for a body structure of a hybrid vehicle in which the battery unit is disposed outside the passenger compartment.For example, JP 2000-247 261 A describes a vehicle body floor structure in which a battery unit is disposed below the floor panel of the vehicle.When a battery is disposed under the floor panel of a vehicle and the vehicle is a vehicle with an FR or 4WD drive system that requires a propeller shaft, the propeller shaft and the center of the battery unit interfere with each other, so that a plurality of battery units need to be disposed on both sides of the propeller shaft in the vehicle width direction.Therefore, when the vehicle body floor structure described in JP 2000-247 261 A is applied to a vehicle that requires a propeller shaft, the temperature in each battery unit may vary.In JP 2000-247 261 A, each battery unit requires a junction box, a battery control unit (BCU), a service plug, etc. As a result, manufacturing costs increase. In JP 2000-247 261 A, each battery unit requires a junction box, a BCU, a service connector, etc. In addition, additional manufacturing processes are required for attaching the junction box, the BCU, the service connector, etc. to each battery unit.US 2010 / 0 163 322 A1 describes a method for arranging an accumulation device in the vicinity of a vehicle floor which forms a floor wall of a passenger compartment of the vehicle itself. The accumulation device has a heating base wall free of thermal insulation and a non-heating base wall parallel and opposite to the heating base wall and provided with a thermal insulating material layer. The method enables the steps of arranging the accumulation device in a seat obtained in the vicinity of the floor and implementing the accumulation device with symmetry that the inversion of the accumulation device itself inside the seat obtained in the vicinity of the floor in such a way that the heating base wall can likewise be directed either upwards and then towards the passenger compartment or downwards and then towards the external environment.JP H05-208 617 A relates to an electric vehicle driven by an engine whose power source is accumulators mounted on the vehicle. A frame structure is provided under the floor panel of the vehicle compartment of a vehicle, which has strength and rigidity required for an accumulator accommodating part, and which has a shape surrounding the periphery of the floor of a vehicle compartment. Accumulators are mounted in the plane of the frame structure.In view of the above, an object of the present invention is to provide a body structure of a hybrid vehicle that enables an integrated battery unit to be mounted on a vehicle that requires a propeller shaft. This object is achieved by the features of the patent claims.With the body structure of a hybrid vehicle according to the present invention, an integrated battery unit can be mounted on a vehicle that requires a propeller shaft.An embodiment of a body structure according to the present invention will be described below with reference to Figs. 1 to 3. FIG. 1 shows a plan view for schematically illustrating an embodiment of a body structure according to the invention of a hybrid vehicle 10; FIG. 2 shows a side view for schematically illustrating the embodiment of the hybrid vehicle 10 according to the invention; and FIG. 3 is a cross-sectional view taken along a line III-III in FIG. 1.As illustrated in FIGS. 1 to 3, the hybrid vehicle 10 in the present embodiment includes an engine 11 disposed forward in the traveling direction of the hybrid vehicle 10. The engine 11 is connected to an unillustrated electromagnetic clutch. The electromagnetic clutch is connected to a transmission, not shown.That is, the hybrid vehicle 10 transmits a driving force from the engine 11 to the transmission via the electromagnetic clutch. The transmission is formed using a continuously variable transmission. The transmission is connected to a front differential, not shown.The driving force is supplied from the engine in the present embodiment, but the driving force may be supplied from another motor such as an electrically driven motor in addition to an engine. In addition, the driving force may be supplied via any other transmission device, such as a normal clutch, in addition to an electromagnetic clutch. In addition, the transmission is not limited to a continuously variable transmission, but may be any other transmission such as a manual transmission.The front differential gear is connected to front wheel drive shafts, not shown, on the left and right sides. That is, the hybrid vehicle 10 transmits the driving force from the engine 11 to the front wheel drive shafts on the left and right sides via the front differential gear. A transmission 12 is mounted on the rear end of the engine in the front-rear direction of the vehicle.The transmission 12 is connected to a cardan shaft 13. The transmission 12 has a gear, not shown. Because the gear of the transmission 12 is meshed with a ring gear of the front differential gear, a part of the driving force is transmitted to the propeller shaft 13.The propeller shaft 13 extends in the front-rear direction of the vehicle below a floor panel 14 with respect to the vertical direction of the vehicle. The rear side of the propeller shaft in the front-rear direction of the vehicle is connected to a rear differential gear, not shown. The rear differential gear is connected to rear drive shafts, not shown, on the left and right sides. That is, a part of the driving force is transmitted from the propeller shaft 13 to the rear drive shafts on the left and right sides via the rear differential gear.In addition to the propeller shaft 13, an exhaust pipe 9 for exhausting an exhaust gas emitted from the internal combustion engine 11 is disposed below the floor panel 14 with respect to the vertical direction of the vehicle. Therefore, at least the propeller shaft 13 and the exhaust pipe 9 are disposed below the floor panel 14 of the vehicle as described below.In the present embodiment, the body structure of the hybrid vehicle 10 includes a battery unit 15 below the floor panel 14 of the vehicle in addition to the propeller shaft 13 and the exhaust pipe 9.The battery unit 15 combines battery modules 16, a BCU 17, distribution cables 18, a junction box 19, and a service plug 20, and serves as a unit.That is, the battery unit 15 is integrally formed in the present embodiment. As described above, the body structure of the hybrid vehicle 10 includes the propeller shaft 13 extending in the front-rear direction of the vehicle below the floor panel 14.Therefore, when the battery unit 15 is mounted below the floor panel 14 of a conventional hybrid vehicle having an FR drive system or a 4WD drive system, the body structure of the vehicle is divided on both sides of the propeller shaft in the width direction of the vehicle.On the other hand, the present embodiment of the body structure of the hybrid vehicle 10 enables the integrated battery unit 15 to be mounted on the hybrid vehicle 10, which is a vehicle requiring the propeller shaft 13, such as a vehicle having an FR drive system or a 4WD drive system.Specifically, the battery unit 15 is divided into front, middle, and rear portions in the front-rear direction of the vehicle, i.e., has a front-side portion 21, a middle, and a rear-side portion 23. The center part of the battery unit 15 includes a center portion 22, a right side portion 24, and a left side portion 25 on both sides of the center portion 22 in the width direction of the vehicle.That is, the battery unit 15 has five separate portions, i.e., the front side portion 21, the middle portion 22, the rear side portion 23, the right side portion 24, and the left side portion 25. in the battery unit 15, the battery modules 16, the BCU 17, the distribution cables 18, the junction box 19, and the service plug 20 are respectively disposed in a portion among the front side portion 21, the middle portion 22, the rear side portion 23, the right side portion 24, and the left side portion 25, so that the battery unit 15 serves as a unit as described above.Here, the battery modules 16, the BCU 17, the distribution cables 18, the junction box 19, and the service connector 20 constituting the battery unit 15 in the present embodiment are conventional components, and thus will not be described in detail but only simplified.The battery modules 16 are arranged in the right-side section 24 and in the left-side section 25 of the battery unit 15, respectively. Each battery module 16 has a function of supplying electric power to a drive motor serving as a drive source.In the present embodiment, as described above, the battery unit 15 is configured such that two battery modules 16 are respectively disposed on the left and right sides of the propeller shaft 13 in the width direction of the vehicle. However, only one large battery module 16 may be arranged on the left and right sides of the propeller shaft 13, for example. Alternatively, three small battery modules 16 may be arranged on the left and right sides of the propeller shaft 13, respectively.The BCU 17 is disposed in the central portion 22 of the battery unit 15. The BCU 17 has a function of controlling the battery module 16. i.e., the BCU 17 measures the voltages, currents, temperatures, etc. of the battery modules 16 to detect the state of each of the battery modules 16. In addition, the BCU 17 monitors the supply of the electric power from the battery modules 16 to the drive motor.Similar to the ECU 17, the distribution cables 18 are disposed in the middle portion 22 of the battery unit 15. The distribution cables 18 have a function of connecting the battery modules 16 to each other.The distribution cables 19 are provided with the junction box 19. The junction box 19 has functions for connecting, branching and relaying the distribution cables 18.The service plug 20 is disposed in the front side portion 21 of the battery unit 15. The service connector 20 has a function of interrupting a high voltage generated by the battery modules 16. Therefore, the service plug 20 interrupts a high voltage when the battery unit 15 is mounted or dismounted, thus providing safe working conditions.In this way, in the battery unit 15 in the present embodiment, the battery modules 16, the BCU 17, the distribution cables 18, the junction box 19, and the service plug are respectively disposed in a portion among the front side portion 21, the middle portion 22, the rear side portion 23, the right side portion 24, and the left side portion 25, so that the battery unit 15 is integrally formed.Therefore, with the present embodiment of the vehicle body structure of the hybrid vehicle 10, the number of BCUs 17, distribution cables 18, junction boxes 19, and service connectors 20 can be reduced, whereby the manufacturing cost can be reduced.The integrated battery unit 15 is disposed below the bottom plate 14 so as to cover the propeller shaft 13. In addition, the battery unit 15 has a recess 26 for receiving the propeller shaft 13. That is, the battery unit 15 is disposed below the bottom plate 14 such that the battery unit and the propeller shaft 13 do not interfere with each other due to the recess.Here, the battery unit 15 is disposed at the deepest point as viewed in the vertical direction in the present embodiment. That is, the battery unit 15 is not disposed at a portion having protrusions and recesses, such as the rear side of the rear seats, so that the lower side of the battery unit 15 in the vertical direction of the vehicle may be formed in any shape.Therefore, the battery unit 15 has a smooth-shaped bottom surface. For this reason, in the present embodiment of the body structure of the hybrid vehicle 10, the battery modules 16, the BCU 17, the distribution cables 18, the junction box 19, and the service plug 20 constituting the battery unit 15 can be easily arranged, in particular, the wiring of the BCU 17, the distribution cables 19, and the junction box 19 can be easily performed, so that the working conditions in the assembly and disassembly can be improved.The recess 26 of the battery unit 15 in the present embodiment has an insulating member on the surface of the recess 26 facing the propeller shaft 13. The insulating member on the surface of the recess itself is a heat insulating plate.Therefore, in the present embodiment, the battery unit 15 can prevent heat generated by the battery unit 15 from being transferred into the recess 26. On the other hand, the battery unit 15 can prevent heat generated from the exhaust pipe accommodated in the recess 26 from being transferred to the battery unit 15.As described above, the battery unit 15 is disposed below the floor panel 14 so as to cover the propeller shaft 13, that is, so as to cover the propeller shaft 13 as viewed from below in the vertical direction of the vehicle, so that the battery unit 15 serves as a receptacle that receives the propeller shaft 13.As a result, the battery unit 15 in the present embodiment can prevent the propeller shaft 13 from coming off. When the propeller shaft 13 disengages, the tension of the propeller shaft 13 may cause the vehicle to be lifted, i.e., a so-called stick jump-up phenomenon may occur.That is, the battery unit 15 in the present embodiment accommodates the propeller shaft 13 to prevent occurrence of a stick-up phenomenon, thereby improving the safety of the vehicle.In the present embodiment, the hybrid vehicle 10 is a vehicle that requires the propeller shaft 13, such as a vehicle having an FR drive system or a 4WD drive system, but a similar effect is also obtained for a vehicle without a propeller shaft 13, such as a vehicle having an FF drive system, or for a vehicle in which the exhaust pipe 9 and similar components are disposed under the floor panel 14 of the vehicle.On the outer periphery of the battery unit 15, a flange (mounting portion) 28 is provided, via which the battery unit 15 is mounted on the bottom plate 14. The flange 28 has bolts.Therefore, since the battery unit 15 is integrally formed as described above, the battery unit 15 can be mounted on the bottom plate 14 by inserting the bolts into the bottom plate 14, so that the mounting can be easily performed.In addition, the battery unit 15 has a first contact surface 27 and a second contact surface 29, the first contact surface 27 coming into contact with the floor panel 14 and the second contact surface 29 coming into contact with a side pillar when the battery unit 15 is mounted on the floor panel 14.Therefore, the battery unit 15 as well as the floor panel 14 and the side pillar have a function of absorbing an impact force applied when the vehicle experiences a side impact. As a result, the body structure of the hybrid vehicle 10 enables the battery unit 15 to serve as a stiffener during a side collision, so that safety in a side collision can be improved.The front side of the battery unit 15 is connected to a cover member for the engine 11 in the present embodiment. In this way, the body structure of the hybrid vehicle 10 in the present embodiment has the battery integrated unit 15, so that the number of connection points can be larger than that of a battery divided unit. Therefore, the battery unit 15 can be stably fixed.Therefore, the body structure of the hybrid vehicle 10 in the present embodiment enables mounting of the integrated battery unit 15 under the floor panel 14 of the vehicle 10 requiring a propeller shaft 13, so that the working conditions in mounting and dismounting of the battery unit 15 can be improved.In addition, in the present embodiment, the battery unit 15 of the body structure of the hybrid vehicle 10 is mounted below the floor panel 14 and the front row of seats. Here, the lower part is located under the front row of seats at a position furthest from the wheels, so that a relatively larger space is available for this than at other portions of the vehicle.Therefore, with the present embodiment, even when the battery unit 15 is disposed below the floor panel 14, the body structure of the hybrid vehicle 10 is prevented from being reduced in the passenger compartment of the vehicle, so that the influence on the passenger compartment of the vehicle can be reduced.In the present embodiment, the body structure of the hybrid vehicle 10 enables a cooling device 30 for supplying cooling air into the battery unit 15 to be connected to the rear portion 23 of the battery unit 15.The cooling device 30 includes a cooling fan 31 for generating cooling air, and a cooling passage 32 for blowing the cooling air from the cooling fan 31 into the battery unit 15. The cooling fan 31 and the cooling duct 32 constituting the cooling device 30 are known in the art and therefore will not be described in detail.The battery unit 15 is integrally formed in the present embodiment as described above. That is, the present embodiment of the body structure of the hybrid vehicle 10 enables cooling air to be blown into the battery unit 15 from the cooling fan 31 without scattering, so that the cooling air can be blown uniformly into the battery unit 15.Therefore, the present embodiment of the body structure of the hybrid vehicle 10 can suppress temperature fluctuations of the battery modules 16 in the battery unit 15.Therefore, the present embodiment of the body structure of the hybrid vehicle 10 enables the integrated battery unit 15 to be mounted on the hybrid vehicle 10 that requires a propeller shaft 13, whereby temperature fluctuations in the battery unit 15 can be suppressed.

Claims

A body structure of a hybrid vehicle (10) driven using power of an engine (11) and power of a drive motor driven by electric power supplied from a battery, the body structure comprising: a propeller shaft (13) disposed below a floor panel (14) with respect to the vertical direction of the vehicle (10) so as to extend in a front-rear direction of the hybrid vehicle (10), and configured to transmit the power of the engine (11) and the power of the drive motor to at least one rear wheel; and a battery integrated unit (15) disposed under the floor panel (14) so as to cover the propeller shaft (13) from below as viewed in the vertical direction of the vehicle, the battery integrated unit (15) including at least the battery, the battery unit (15) including a recess (26) for receiving the propeller shaft (13).The body structure according to claim 1, wherein the recess (26) has an insulating member on a surface of the recess (26) facing the propeller shaft (13).The body structure according to claim 1 or 2, wherein the battery unit (15) has a smooth bottom surface.The body structure according to any one of claims 1 to 3, wherein the battery unit (15) has a contact surface (29) that is in contact with a vehicle frame in the width direction of the vehicle (10).The body structure according to any one of claims 1 to 4, wherein an outer periphery of the battery unit (15) has a mounting portion (28) for mounting the battery unit (15) to the floor panel (14).The body structure according to any one of claims 1 to 5, wherein the recess (26) serves as a receptacle for receiving the propeller shaft (13).The body structure according to any one of claims 1 to 6, wherein the battery unit (15) is connected to a cover member of the internal combustion engine (11).

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