JP2020196300A - Battery mounting structure of vehicle - Google Patents

Abstract

To provide a battery mounting structure of a vehicle which effectively inhibits transmission of heat of a battery to a vehicle cabin.SOLUTION: A battery mounting structure of a vehicle includes: a battery 4 disposed below a floor panel 3; and an elastic member 7 disposed between the floor panel 3 and the battery 4. The battery mounting structure further includes a heat shieling member (a heat shielding sheet) 8 (at least one of) between the elastic member 7 and the battery 4 (and between the floor panel 3 and the elastic member 7).SELECTED DRAWING: Figure 2

Description

The present invention relates to a vehicle battery-mounted structure.

The following Patent Document 1 discloses a mounting structure of a battery in a vehicle (battery electric vehicle (BEV)). The battery disclosed in Patent Document 1 is mounted below the floor panel. A cushioning member such as urethane foam is arranged between the battery (battery casing) and the floor panel.

JP-A-2009-193942

As the battery for the BEV, for example, a high voltage lithium ion battery is used. Batteries can generate heat and become hot. The cushioning member such as urethane foam arranged on the battery disclosed in Patent Document 1 does not positively contribute to suppressing the heat conduction of the battery to the vehicle interior.

Therefore, an object of the present invention is to provide a battery-mounted structure of a vehicle that effectively suppresses the conduction of heat of the battery to the vehicle interior.

The vehicle battery-mounted structure according to the present invention includes a floor panel of a vehicle body, a battery arranged below the floor panel, and an elastic member between the floor panel and the battery. Further, the battery mounting structure further includes a heat shield member at least between the elastic member and the battery and between the floor panel and the elastic member.

According to the battery-mounted structure of the vehicle according to the present invention, the heat conduction of the battery to the vehicle interior can be effectively suppressed.

It is the schematic side sectional view of the vehicle which provided the battery-mounted structure which concerns on embodiment. It is a schematic partial sectional view of the battery mounting structure which concerns on 1st Embodiment. It is a schematic partial sectional view of the battery mounting structure which concerns on 2nd Embodiment. It is a schematic partial sectional view of the battery mounting structure which concerns on 3rd Embodiment.

Hereinafter, the battery-mounted structure of the vehicle according to the embodiment will be described with reference to the drawings.

As shown in FIG. 1, the vehicle provided with the battery-mounted structure according to the embodiment is the Battery Electric Vehicle (BEV) 1. The BEV1 is provided with a battery 4 below the floor panel 3 of the vehicle interior 2, and is provided with a motor and an inverter in the front motor room 5. The floor panel 3 is made of steel. The DC power stored in the high-voltage battery 4 is converted into AC by an inverter and then supplied to a three-phase AC motor. The BEV1 runs on the output (driving force) of this motor. The battery 4 includes a casing 4a, and the battery cell is housed inside the casing 4a. A plurality of modules incorporating a plurality of battery cells may be housed inside the casing 4a. The casing 4a is made of steel or resin, but may be made of an aluminum alloy, and functions as a protective wall to prevent collision of water or pebbles of the internal battery cell. The BEV1 of the present embodiment is equipped with a plurality of batteries 4, and these batteries 4 are mounted on a frame 6, and the frame 6 is fixed to the vehicle body so as to be suspended from the floor panel 3.

An elastic member 7 is arranged in a compressed state between the floor panel 3 and the upper surface of the battery 4 (that is, the upper surface plate of the casing 4a). The elastic member 7 is a foam of semi-independent semi-open cells. Then, at least one of the space between the elastic member 7 and the battery 4 (first embodiment: FIG. 2) and between the floor panel 3 and the elastic member 7 (second embodiment: FIG. 3) is a heat shield member. The heat shield sheet 8 is further provided. The heat shield sheet 8 is made of a material that has fire resistance (flame retardancy) and heat resistance by itself and does not easily transfer heat from one surface to the other. Specifically, the heat shield sheet 8 is formed of an inorganic fiber member and has a thickness of 1 mm or more and 2 mm or less. Since the heat generated by the battery 4 is blocked by the heat shield sheet 8, the heat generated by the battery 4 is prevented from being conducted to the vehicle interior 2 via the floor panel 3.

In the present embodiment, the elastic member 7 is arranged in a compressed state between the floor panel 3 and the battery 4. Therefore, the elastic member 7 is in close contact with the floor panel 3 and the battery 4 (that is, the upper surface plate of the casing 4a), and is preloaded on the floor panel 3 and the battery 4 (that is, the upper surface plate of the casing 4a) by the elastic restoring force. Is given. Further, the surfaces of the floor panel 3 and the battery 4 are often not flat, for example, beads for ensuring rigidity are formed. By putting the elastic member 7 in a compressed state, the heat shield sheet 8 can be brought into close contact with the surface of the floor panel 3 or the battery 4 by its elastic restoring force, and the heat shield sheet 8 can be firmly held without causing misalignment. Can be retained.

The battery 4 mounted on the frame 6 is lifted from below the floor panel 3 toward the floor panel 3 and attached to the vehicle body. At this time, by arranging the elastic member 7 in advance between the floor panel 3 and the battery 4, the elastic member 7 is in a compressed state after the battery 4 is mounted on the vehicle. The elastic member 7 may be previously adhered or placed on the upper surface of the battery 4 (casing 4a), or may be previously adhered to the lower surface of the floor panel 3. The heat shield sheet 8 is also arranged or attached at an appropriate position.

Since the floor panel 3 and the battery 4 (the upper surface plate of the casing 4a) are preloaded by the elastic member 7, the vibration of the floor panel 3 and the battery 4 (the upper surface plate of the casing 4a) is suppressed, that is, vibration is suppressed. The casing. Further, since the elastic member 7 is brought into close contact with the floor panel 3 and the battery 4 (the upper surface plate of the casing 4a), the elastic member 7 attenuates the vibration of the floor panel 3 and the battery 4 (the upper surface plate of the casing 4a). That is, the elastic member 7 also functions as a vibration damping material like an asphalt sheet or the like. The floor panel 3 and the battery 4 (the upper surface plate of the casing 4a) vibrate due to the air propagating sound from the outside of the vehicle and the solid propagating sound of the sound generated by the motor and the tire, and these vibrations are suppressed as described above. To.

Further, the elastic member 7 of the present embodiment is a semi-independent semi-open cell foam. If it is an open cell foam, it is easily crushed and an appropriate elastic restoring force cannot be obtained, so that a desired preload cannot be applied. Therefore, by making the elastic member 7 a semi-independent semi-open cell foam, an appropriate elastic restoring force can be obtained and a desired preload can be applied. The compressibility of the elastic member 7 (semi-independent semi-open cell foam) is preferably 10% or more and 75% or less. The compressibility here is, for example, 35% when the initial thickness of the elastic member 7 is 100 mm and the thickness after compression is 65 (= 100-35) mm. That is, (compression rate) [%] = {[(initial thickness) − (thickness after compression)] / (initial thickness)} × 100. Since the compressed area does not change, the compressibility can be said to be the volume reduction rate.

As described above, beads may be formed on the surfaces of the floor panel 3 and the battery 4, so that the compression ratio varies slightly depending on the location. If the compression ratio is less than 10%, the desired preload cannot be applied. If the compression ratio exceeds 75%, the elastic restoring force at the time of compression becomes too large, and the assembling property of the battery 4 to the vehicle body deteriorates. In order to strike a good balance between the desired preload (that is, stable damping effect) and the above-mentioned assembly property, the elastic modulus is 35% (specifically, 30% or more because there is some variation depending on the location as described above). 40% or less) is preferable. The elastic member 7 also functions as a cushioning member between the floor panel 3 and the battery 4, as in Patent Document 1 described above.

Further, since the elastic member 7 contains closed cells, the intrusion of water into the elastic member 7 is suppressed. Further, since the elastic member 7 contains air bubbles, it has a certain degree of sound absorbing property, and functions not only as a vibration damping material but also as a sound absorbing material. Furthermore, since the elastic member 7 contains air bubbles, it also has a certain degree of heat insulating property, and also functions as a heat insulating material to suppress the conduction of heat generated by the battery 4 to the vehicle interior 2. The elastic member 7 as the semi-independent semi-open cell foam can also function as a buffer for storing the heat shielded by the heat shield sheet 8.

The heat shield sheet 8 of the first embodiment (FIG. 2) and the second embodiment (FIG. 3) has a shape larger than the plan view shape of the battery 4 (top plate shape of the casing 4a), and has a plan view. Overlaps the entire battery 4 in. That is, the heat shield sheet 8 covers the entire battery 4 in a plan view. However, the heat shield sheet 8 may cover only a part of the battery 4 instead of the entire battery 4. However, in terms of heat shielding performance, it is preferable that the heat shielding sheet 8 covers the entire battery 4.

In the third embodiment shown in FIG. 3, the entire surface of the elastic member 7 (semi-independent semi-open cell foam) is covered with the heat shield sheet 8 (the heat shield sheet 8 is a battery in a plan view). It is also an example of a form that covers the whole of 4). By doing so, it is possible to improve the heat shielding performance of the battery-mounted structure of the present embodiment without hindering the improvement of the sound vibration performance by the elastic member 7 described above. In particular, since the vehicle of the present embodiment is BEV1, it is not equipped with an internal combustion engine as a noise generation source, and there is a high demand for sound vibration performance. Therefore, the improvement of the sound vibration performance by the elastic member 7 is a great advantage in the present embodiment.

The battery mounting structure according to the present embodiment includes an elastic member 7 and a heat shield member (heat shield sheet) 8 between the floor panel 3 and the battery 4 (top plate of the casing 4a) mounted below the floor panel 3. ing. Therefore, even if the battery 4 generates heat and becomes high in temperature, the heat shield member (heat shield sheet) 8 shields the heat, so that it is possible to prevent the heat from being conducted to the vehicle interior via the floor panel 3.

Here, the heat shield member (heat shield sheet) 8 has a shape larger than the plan view shape of the battery 4, and the outer surface (FIG.) of the battery 4 facing the heat shield member (heat shield sheet) 8 is provided. It is preferable to cover all of them. That is, it is preferable that the heat shield member (heat shield sheet) 8 covers the entire battery 4. If the entire battery 4 is covered, the heat generated by the battery 4 can be reliably suppressed from being conducted to the passenger compartment 2.

Further, it is particularly preferable that all the surfaces of the elastic member 7 are covered with the heat shield member (heat shield sheet) 8. Since the (heat shield sheet) 8 is provided in two layers between the battery 4 and the floor panel 3, the heat shield performance is further improved. Further, since the elastic member 7 is wrapped with the (heat shield sheet) 8, the elastic member 7 can be protected from a high temperature.

The heat shield member is preferably a heat shield sheet 8 having a thickness of 1 mm or more and 2 mm or less, which is formed of an inorganic fiber member as in the above embodiment. By forming the heat shield member with a thin inorganic fiber member, the mass of the heat shield member can be reduced. In recent years, in a hybrid electric vehicle (HEV) equipped with an internal combustion engine and a battery, reduction of fuel consumption (which can be said to be reduction of CO ₂ emissions) is an important matter, and weight reduction of the vehicle is important. Further, in BHE1 such as the present embodiment in which the internal combustion engine is not mounted, it is important to reduce the weight of the vehicle in order to extend the mileage (it can be said that the electric cost is improved, which is the electric fuel consumption). Will be). In particular, in the case of BHE 1 as in the above embodiment, since the volume of the battery 4 mounted on the vehicle is large and the area of the heat shield sheet 8 is large, it is effective to reduce the mass of the heat shield sheet 8.

The elastic member 7 is a semi-independent semi-open cell foam, and is preferably arranged between the floor panel 3 and the battery 4 in a compressed state. By mounting the elastic member 7 in a compressed state, the vibration damping effect of the floor panel 3 (the upper surface plate of the casing 4a) by imparting a preload to the floor panel 3 (and the upper surface plate of the casing 4a of the battery 4) can be obtained. can get. At the same time, the elastic member 7 also functions as a damping material for attenuating the vibration of the floor panel 3 (upper surface plate of the casing 4a). As a result, the sound vibration performance is improved. Compared with the asphalt sheet that has been used as a vibration damping material so far, if the elastic member 7 in the compressed state is used to obtain the same vibration damping effect, the weight can be reduced. As mentioned above, weight reduction is important.

Further, since the elastic member 7 is a semi-independent semi-open cell foam, a heat insulating effect (and a sound absorbing effect) due to the bubbles can be obtained. That is, the elastic member 7 also contributes to the improvement of the heat shield (heat insulation) performance by the heat shield member (heat shield sheet) 8. Further, since the elastic member 7 is a semi-independent semi-open cell foam, the elastic restoring force due to the closed cells can be secured, and the above-mentioned preload is likely to occur. That is, the elastic member 7 also contributes to the improvement of sound vibration performance from this point. Since the elastic member 7 is a semi-independent semi-open cell foam, it is possible to suppress the intrusion of water into the elastic member 7 by the closed cells.

Further, the compression ratio of the semi-independent semi-open cell foam (elastic member 7) is effectively in the range of 10% or more and 75% or less, and in particular, the compression ratio is stably described above as 30% or more and 40% or less. The inventors have found that the sound vibration performance and the heat shielding (insulation) performance can be achieved as desired performances.

The present invention is not limited to the embodiments described above. For example, the vehicle in the above embodiment is a BEH1 that does not have an internal combustion engine, but it can also be installed in a battery-mounted structure in an HEV that includes both an internal combustion engine and a battery that supplies electric power to a motor for a vehicle running motor. Applicable. Further, in the above embodiment, a plurality of batteries 4 are mounted, and one heat shield sheet 8 (elastic member 7) covers all the batteries 4, but each battery 4 has a heat shield sheet 8 (elastic member 7). May be provided.

1 Battery Electric Vehicle (BEV)
2 Car room 3 Floor panel 4 Battery 4a (Battery) Casing 5 Motor room 6 Frame 7 Elastic member (semi-independent semi-continuous bubble foam)
8 Heat shield sheet (heat shield member)

Claims (6)

In a battery-mounted structure of a vehicle including a battery arranged below the floor panel and an elastic member arranged between the floor panel and the battery.
A vehicle battery-mounted structure, characterized in that a heat shield member is further provided between the elastic member and the battery, and at least one between the floor panel and the elastic member. The battery-mounted structure of a vehicle according to claim 1, wherein the heat shield member has a shape larger than the plan view shape of the battery and overlaps the entire battery in the plan view. The vehicle battery-mounted structure according to claim 2, wherein all the surfaces of the elastic member are covered with the heat shield member. The vehicle battery-mounted structure according to any one of claims 1 to 3, wherein the heat shield member is a heat shield sheet having a thickness of 1 mm or more and 2 mm or less formed of an inorganic fiber member. .. The elastic member according to any one of claims 1 to 4, wherein the elastic member is a semi-independent semi-open cell foam and is arranged in a compressed state between the floor panel and the battery. Vehicle battery-equipped structure. The vehicle battery-mounted structure according to claim 5, wherein the semi-independent semi-open cell foam has a compressibility of 10% or more and 75% or less.

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