Vehicle underbody structure

Abstract

This disclosure aims to provide vibration control measures for certain electronic devices housed in an internal space formed between an upper case and a lower case. [Solution] The underbody structure of the vehicle comprises: a first support column with one end installed at a fixed part and the other end standing upright on the upper case side; a first cushioning material installed on the surface of the other end of the first support column and compressed by the first support column and the equipment base; a second support column with one end installed at a position opposite the first cushioning material across the equipment base and the other end standing upright on the upper case side and in contact with the upper case; and a second cushioning material installed at a position opposite the second support column across the upper case and compressed by the upper case and the vehicle floor panel.

Description

Technical Field

[0001] The present disclosure relates to a vehicle underfloor structure.

Background Art

[0002] Patent Document 1 discloses a battery capable of protecting a battery cell from a load input in the vertical direction with respect to a case.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in a case that houses a battery cell as shown in Patent Document 1, in addition to the battery cell, electronic devices such as an ECU (Electronic Control Unit) and an SBM (Satellite Battery Module) may be housed. In that case, it is necessary to suppress vibrations applied to the electronic devices to protect the electronic devices, but Patent Document 1 does not disclose anything regarding the protection of the electronic devices housed in the case, leaving room for improvement.

[0005] Therefore, an object of the present disclosure is to provide a vehicle underfloor structure capable of taking measures against vibrations of a predetermined electronic device housed in an internal space formed between an upper case and a lower case.

Means for Solving the Problems

[0006] The underbody structure of a vehicle according to claim 1 includes a lower case on which a battery module comprising a plurality of battery cells is installed, a junction box fixed to the upper side of the vehicle of the lower case at a fixing portion provided facing the lower case, an equipment base on which predetermined electronic equipment is installed and attached to the lower case at a plurality of mounting points so as to cover the junction box, and an upper covering which covers the lower case and forms an internal space between the lower case and the battery module, the junction box, and the equipment base. The system comprises a per case, a first support column with one end installed on the fixing part and the other end standing upright on the upper case side, a first cushioning material installed on the surface of the other end of the first support column and compressed by the first support column and the equipment base, a second support column with one end installed at a position opposite the first cushioning material across the equipment base and the other end standing upright on the upper case side and in contact with the upper case, and a second cushioning material installed at a position opposite the second support column across the upper case and compressed by the upper case and the vehicle's floor panel.

[0007] In the vehicle underbody structure according to claim 1, the compressed first cushioning material suppresses the movement of the equipment base downward in the vertical direction of the vehicle during vibrations downward in the vertical direction of the vehicle. Furthermore, in the same vehicle underbody structure, the compressed second cushioning material suppresses the movement of the equipment base upward in the vertical direction of the vehicle during vibrations upward in the vertical direction of the vehicle. As a result, this vehicle underbody structure makes it possible to take measures against vibrations of predetermined electronic equipment housed in the internal space formed between the upper case and the lower case.

[0008] The underbody structure of the vehicle according to claim 2 is as described in claim 1, wherein the fixing portion is a recessed portion on the lower case side, the junction box is fixed to the lower case by fastening a collar inserted into a hole at the bottom of the recess to the lower case, and one end of the first support column is inserted into the recess and in contact with the fastening device.

[0009] In the vehicle underbody structure according to claim 2, the junction box is fixed to the lower case by fastening a collar inserted into a hole at the bottom of the recess with a fastener. One end of the first support column is inserted into the recess and in contact with the fastener. As a result, with this vehicle underbody structure, when the vehicle vibrates downward in the vertical direction, the load can be transmitted to the fastener, collar, and lower case, and the input of load to the junction box can be avoided.

[0010] The underbody structure of the vehicle according to claim 3 is as described in claim 2, wherein, in the state in which the junction box and the equipment base are attached to the lower case, the plurality of mounting points are located outward in the vehicle width direction from the junction box, the junction box is fixed to the lower case in a plurality of recesses recessed into the lower case side, and the recess is the recess that is closest to the midpoint between adjacent mounting points in the vehicle width direction among the plurality of recesses.

[0011] In the vehicle underbody structure according to claim 3, when the junction box and equipment base are attached to the lower case, the multiple mounting points are located outward in the vehicle width direction from the junction box. The recess into which the first support column is inserted is the recess closest to the midpoint between adjacent mounting points in the vehicle width direction among the multiple recesses. As a result, with this vehicle underbody structure, the vibration strength of the equipment base can be improved by pressing down the central portion in the vehicle width direction of the equipment base, which is not fixed to the lower case, with the first support column, the first cushioning material, the second support column, and the second cushioning material.

[0012] The underbody structure of the vehicle according to claim 4 is, in claim 2, wherein the junction box is fixed to the lower case in a plurality of recesses recessed into the lower case side, and the recesses are all of the plurality of recesses.

[0013] In the vehicle underbody structure according to claim 4, the recess into which the first support column is inserted is all of the multiple recesses. As a result, this vehicle underbody structure can improve the vibration strength of the equipment base compared to a configuration in which the first support column is inserted into only some of the multiple recesses. [Effects of the Invention]

[0014] As explained above, the underbody structure of a vehicle according to this disclosure can be used to counteract vibrations of certain electronic devices housed in the internal space formed between the upper case and the lower case. [Brief explanation of the drawing]

[0015] [Figure 1] This is a schematic diagram showing a vehicle equipped with a battery. [Figure 2] This is a top-down plan view that schematically shows the undercarriage structure of the vehicle. [Figure 3] This is a cross-sectional view of AA in Figure 2. [Modes for carrying out the invention]

[0016] Embodiments of this disclosure will be described below with reference to the drawings. In the drawings, arrow U indicates the upper side of the vehicle in the vertical direction, and arrow D indicates the lower side of the vehicle in the vertical direction. Arrow Fr indicates the front side of the vehicle in the longitudinal direction, and arrow Re indicates the rear side of the vehicle in the longitudinal direction. Arrow L indicates the left side in the vehicle width direction, and arrow R indicates the right side in the vehicle width direction. The upper side of the vehicle in the vertical direction is an example of the "upper side of the vehicle" in this disclosure.

[0017] (First embodiment) First, a first embodiment according to the present disclosure will be described.

[0018] Figure 1 is a schematic diagram showing a vehicle 100 equipped with a battery 10. The vehicle 100 shown in FIG. 1 is equipped with a battery 10. The battery 10 is mounted on the vehicle 100 that includes an electric motor (electric motor) as a driving source for traveling, and outputs DC power applicable to driving the electric motor. The vehicle 100 is, for example, a hybrid vehicle (HEV: Hybrid Electric Vehicle), a plug-in hybrid vehicle (PHEV: Plug-in Hybrid Electric Vehicle), an electric vehicle (BEV: Battery Electric Vehicle), or the like.

[0019] The battery 10 is disposed below the floor panel 150 of the vehicle 100 in the vehicle's vertical direction. The battery 10 includes a housing case 15, a plurality of battery modules 20, a junction box 30, and the like.

[0020] The housing case 15 is composed of an upper case 80 (see FIG. 3) and a lower case 40 (see FIGS. 2 and 3), and a plurality of battery modules 20, a junction box 30, and the like are housed inside the housing case 15.

[0021] The plurality of battery modules 20 are arranged side by side in the vehicle's front-rear direction. Each of the plurality of battery modules 20 includes a plurality of battery cells (not shown). The plurality of battery cells are arranged side by side in the vehicle's width direction.

[0022] The battery cell is a secondary battery such as a nickel-metal hydride battery or a lithium-ion battery. The battery cell may use a liquid electrolyte or a solid electrolyte. The battery cell may be a unit capacitor configured to be chargeable and dischargeable. The battery cell is, for example, rectangular in shape.

[0023] When the junction box 30 is placed inside the housing case 15, it is positioned further forward in the vehicle's longitudinal direction than the multiple battery modules 20. The junction box 30 is electrically connected to the multiple battery modules 20. The junction box 30 is a device (electrical distribution box) that relays the electrical connections between devices.

[0024] Figure 2 is a top-view plan view schematically showing the underside of the floor panel 150 in the vertical direction of the vehicle, i.e., the underbody structure of the vehicle 100. Figure 2 also shows the underbody structure of the front portion in the longitudinal direction of the vehicle in the lower case 40 where the junction box 30 is located.

[0025] As shown in Figure 2, the junction box 30 is provided facing the lower case 40, that is, the lower side in the vehicle's vertical direction, and has multiple recesses 32 that serve as fixing parts recessed to the lower side in the vehicle's vertical direction. The junction box 30 is fixed to the upper side of the lower case 40 in the vehicle's vertical direction at the recesses 32. The multiple recesses 32 consist of recesses 32A and 32B provided at the right end of the junction box 30 in the vehicle's width direction, recesses 32C and 32D provided in the center of the junction box 30 in the vehicle's width direction, and recesses 32E and 32F provided at the left end of the junction box 30 in the vehicle's width direction. As described above, when the junction box 30 is fixed to the lower case 40, multiple battery modules 20 are installed on the rear side of the junction box 30 in the vehicle's longitudinal direction.

[0026] Furthermore, on the outer side in the vehicle width direction of the junction box 30 in the lower case 40 shown in Figure 2, there are multiple fastening points 42 for attaching the equipment base 50 on which the ECU 54 and SBM 56 are installed. The multiple fastening points 42 consist of fastening points 42A and 42B provided on the right side in the vehicle width direction of the junction box 30, and fastening points 42C and 42D provided on the left side in the vehicle width direction of the junction box 30.

[0027] Here, Figure 2 shows an equipment base 50 that is attached to the lower case 40. On the equipment base 50, an SBM 56 is installed on the right side in the vehicle width direction, and an ECU 54 is installed on the left side of the SBM 56 in the vehicle width direction. The ECU 54 and SBM 56 are examples of "predetermined electronic equipment" in this disclosure.

[0028] The equipment base 50 includes multiple mounting points 52 corresponding to multiple fastening points 42, namely mounting points 52A and 52B provided on the right side in the vehicle width direction of the SBM 56, and mounting points 52C and 52D provided on the left side in the vehicle width direction of the ECU 54. Mounting point 52A is fastened to fastening point 42A, mounting point 52B to fastening point 42B, mounting point 52C to fastening point 42C, and mounting point 52D to fastening point 42D, respectively, using bolts and nuts (not shown). When the junction box 30 and the equipment base 50 are attached to the lower case 40, the equipment base 50 is positioned above the junction box 30 in the vehicle vertical direction. In other words, the equipment base 50 is attached to the lower case 40 so as to cover the junction box 30 at the multiple mounting points 52. Furthermore, when the junction box 30 and the equipment base 50 are attached to the lower case 40, the multiple mounting points 52 of the equipment base 50 are located further outward in the vehicle width direction than the junction box 30.

[0029] Furthermore, in the underbody structure of the vehicle 100 shown in Figure 2, an exhaust pipe 130 is provided on the right side in the vehicle width direction of the lower case 40. The exhaust pipe 130 consists of a straight section 132 that runs along the vehicle's longitudinal direction and a curved section 134 that curves from the front end of the straight section 132 to the left in the vehicle width direction and extends to the front of the vehicle in the vehicle's longitudinal direction. The front end of the lower case 40 has a shape in which the right end in the vehicle width direction is cut out to avoid the exhaust pipe 130. As a result, there is not enough space to install the battery module 20 in this front end, and a junction box 30 and equipment base 50, which require less space than the battery module 20, are placed there.

[0030] Figure 3 is a cross-sectional view AA in Figure 2. Specifically, Figure 3 shows a longitudinal cross-section of the recess 32D, indicated by line AA in Figure 2, when the vehicle width direction is cut vertically, with the junction box 30 and equipment base 50 attached to the lower case 40. The lower case 40 is made of steel plate or the like.

[0031] As shown in Figure 3, a metal collar 36 is inserted into a hole provided in the bottom portion 34, which is the bottom of the groove of the recess 32D. The collar 36 is in contact with a bracket 44 provided on the lower case 40. The recess 32D is then fixed to the lower case 40 by fastening a weld bolt 60, through which the bracket 44 and collar 36 are inserted, with a nut 65. In this way, the junction box 30 is fixed to the lower case 40 by fastening the collar 36 and bracket 44 inserted into the holes of each recess 32 with a weld bolt 60 and a nut 65. The weld bolt 60 and nut 65 are examples of the "fasteners" of this disclosure.

[0032] Furthermore, in Figure 3, the lower portion of the first support column 70, which is a cylindrical member made of resin, is inserted into the recess 32D, and its lower surface is in contact with the nut 65. When inserted into the recess 32D, the first support column 70 is standing upright on the upper side in the vertical direction of the vehicle. A first cushioning material 72, which is a cylindrical member with the same diameter as the first support column 70, is installed on the upper surface of the first support column 70. The first cushioning material 72 is a cushioning material made of, for example, urethane foam. The first cushioning material 72 is compressed by the first support column 70 and the equipment base 50 to a size that provides a pressing load greater than or equal to a predetermined vibration input transmitted to the battery 10.

[0033] A second support column 74 is installed opposite the first cushioning material 72, with the equipment base 50 in between, and its lower portion in the vertical direction of the vehicle is attached to the equipment base 50 by a claw fitting or the like. The second support column 74 is a cylindrical member made of resin with the same diameter as the first support column 70, and when installed on the equipment base 50, it stands upright on the upper side in the vertical direction of the vehicle, with its upper surface in contact with the upper case 80.

[0034] The upper case 80 covers the lower case 40, forming an internal space between it and the lower case 40 that houses the battery module 20, the junction box 30, and the equipment base 50. The upper case 80 is made of steel plate or the like.

[0035] A second cushioning material 76, which is a cylindrical member with the same diameter as the first support column 70, is installed opposite the second support column 74, with the upper case 80 in between. The second cushioning material 76 is a cushioning material made of, for example, urethane foam. The second cushioning material 76 is compressed by the upper case 80 and the floor panel 150 with the same compression ratio as the first cushioning material 72.

[0036] With the above configuration, in the underfloor structure of the vehicle 100, the compressed first cushioning material 72 suppresses the movement of the equipment base 50 downward in the vertical direction of the vehicle during vibrations in the vertical direction of the vehicle. Furthermore, since the movement of the equipment base 50 downward in the vertical direction of the vehicle can be stopped by the first support column 70 and the first cushioning material 72 during vibrations in the vertical direction of the vehicle, contact between the junction box 30 and the equipment base 50 is avoided. In addition, since the movement of the equipment base 50 downward in the vertical direction of the vehicle can be stopped, the vertical gap between the junction box 30 and the equipment base 50 can be reduced, which contributes to reducing the height of the battery 10.

[0037] Furthermore, in the underbody structure of vehicle 100, the junction box 30 is fixed to the lower case 40 by fixing the collar 36 and bracket 44, which are inserted into the holes of each recess 32, with weld bolts 60 and nuts 65. The lower part of the first support column 70 in the vehicle's vertical direction is inserted into the recess 32D and abuts against the nut 65 (see Figure 3). As a result, with the underbody structure of vehicle 100, when the vehicle vibrates downward in the vertical direction, the amplitude is suppressed and the load is transmitted to the nut 65, collar 36, and lower case 40, thus avoiding the input of load to the junction box 30. Therefore, damage to the junction box 30 when the vehicle vibrates downward in the vertical direction is suppressed.

[0038] Furthermore, in the underbody structure of the vehicle 100, the compressed second cushioning material 76 suppresses the movement of the equipment base 50 upward in the vertical direction of the vehicle during vibrations in the vertical direction of the vehicle. Specifically, during vibrations in the vertical direction of the vehicle, the amplitude is suppressed while the load can be transmitted to the second support column 74, the upper case 80, and the floor panel 150, thus avoiding contact between the upper case 80 and the ECU 54 and SBM 56. This suppresses damage to the ECU 54 and SBM 56 during vibrations in the vertical direction of the vehicle.

[0039] As explained above, the underbody structure of the vehicle 100 makes it possible to reduce vibrations of the ECU 54 and SBM 56 housed in the internal space formed between the upper case 80 and the lower case 40.

[0040] Furthermore, in the underbody structure of the vehicle 100, the recesses 32 into which the first support column 70 is inserted are, among the multiple recesses 32, recess 32C closest to the midpoint between adjacent mounting points 52A and 52C in the vehicle width direction, and recess 32D closest to the midpoint between mounting points 52B and 52D. As a result, with the underbody structure of the vehicle 100, the vibration strength of the equipment base 50 can be improved by pressing down the central portion in the vehicle width direction of the equipment base 50, which is not fixed to the lower case 40, with the first support column 70, the first cushioning material 72, the second support column 74, and the second cushioning material 76.

[0041] (Second embodiment) Next, a second embodiment according to the embodiments of this disclosure will be described, omitting or simplifying any overlapping parts with the above embodiments.

[0042] In the underbody structure of the vehicle 100 according to the second embodiment, the recesses 32 into which the first support column 70 is inserted are all of the multiple recesses 32, specifically recesses 32A to 32F. As a result, the vibration strength of the equipment base 50 can be improved with the underbody structure of the vehicle 100 compared to a configuration in which the first support column 70 is inserted into only some of the multiple recesses 32. [Explanation of symbols]

[0043] 20 Battery Modules 30 Junction Box 32 recesses 50 Equipment base 52 mounting points 54 ECU (Specified Electronic Unit) 56 SBM (Specified Electronic Device) 70 1st pillar 72 1st buffer material 74 Second pillar 76 Second buffer material 80 Upper Case 100 vehicles 150 Floor Panels

Claims

1. A lower case in which a battery module, consisting of multiple battery cells, is installed, A junction box is fixed to the vehicle-upper side of the lower case in a fixing portion provided facing the lower case side, A device base is mounted on the lower case so as to cover the junction box at multiple mounting points, on which a predetermined electronic device is installed. An upper case that covers the lower case and forms an internal space between itself and the lower case for housing the battery module, the junction box, and the equipment base, A first support column, one end of which is attached to the aforementioned fixed part and the other end of which stands upright toward the upper case side, A first cushioning material is installed on the other end surface of the first support column and is compressed by the first support column and the equipment base, A second support column is provided, with one end positioned opposite the first cushioning material across the equipment base, and the other end standing upright on the upper case side and in contact with the upper case. A second cushioning material is installed in a position opposite to the second support column, with the upper case in between, and is compressed by the upper case and the vehicle's floor panel. A vehicle underbody structure equipped with the following features.

2. The aforementioned fixing portion is a recessed area on the lower case side, The junction box is fixed to the lower case by fastening a collar inserted into a hole at the bottom of the recess to the lower case with a fastener. The one end of the first support column is inserted into the recess and abuts against the fastener. The underbody structure of a vehicle according to claim 1.

3. With the junction box and the equipment base mounted on the lower case, the plurality of mounting points are located outward in the vehicle width direction from the junction box. The junction box is fixed to the lower case in a plurality of recesses that are recessed into the lower case side. The aforementioned recess is the recess among the plurality of recesses that is closest to the midpoint between adjacent mounting points in the vehicle width direction. The underbody structure of a vehicle according to claim 2.

4. The junction box is fixed to the lower case in a plurality of recesses that are recessed into the lower case side. The aforementioned recess is all of the aforementioned plurality of recesses. The underbody structure of a vehicle according to claim 2.

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