JP5266677B2 - Power supply temperature control structure and vehicle - Google Patents

Description

  The present invention relates to a temperature control structure for maintaining a power supply body at an appropriate operating temperature.

  As a driving or auxiliary power source for hybrid vehicles, electric vehicles, etc., from a plurality of lithium ion batteries, a cooling liquid for cooling these lithium ion batteries, and a battery pack containing these lithium ion batteries and cooling liquid A power supply device is known.

  This type of power supply device generates heat during charging and discharging, and it is considered that battery deterioration proceeds when the battery temperature exceeds a predetermined temperature (60 ° C. in the case of a lithium ion battery). Therefore, it is necessary to provide a heat dissipation structure that dissipates heat from the power supply device to the outside of the vehicle.

Here, a method is conceivable in which the battery pack is directly fixed to a floor panel, which is a heat radiating part of the vehicle, and the heat of the power supply device is radiated to the outside of the vehicle through the floor panel.
JP-A-10-246112 JP 2006-102034 A JP 2003-291656 A

  By the way, if a proper operating temperature exists in the power supply device and the battery temperature is lower than a predetermined temperature (−10 ° C. in the case of a lithium ion battery), a battery output corresponding to the vehicle output cannot be obtained.

  Therefore, when the battery pack is directly fixed to the floor panel, the heat of the power supply device is radiated from the floor panel, and there is a possibility that sufficient battery output cannot be obtained. In this case, a method of arranging a heater in the vicinity of the power supply device and heating the power supply device using this heater can be considered, but this method increases the cost.

  Accordingly, an object of the present invention is to provide a temperature adjustment structure for a power supply body for maintaining the power supply body at an appropriate operating temperature at a low cost.

In order to solve the above-described problems, a temperature control structure for a power source body according to the present invention is configured to contact a power source body disposed at a position away from a heat radiating portion of a vehicle, and to dissipate heat of the power source body A heat transfer member for transferring heat to the portion, and the heat transfer member is disposed at a position sandwiching the power supply body, and when the temperature becomes lower than a threshold value, the contact area with the power supply body is reduced. An extension part that extends toward the heat dissipation part from the contact surface that contacts the power supply body is fixed to the heat dissipation part, thereby functioning as a bracket for fixing the power supply body to the heat dissipation part characterized in that it. The heat transfer member can be made of a bimetal or a shape memory alloy.

  Heat dissipation may be promoted by applying thermally conductive grease to the contact surfaces of the heat transfer member and the power supply body.

  The heat transfer member may be fixed to the power supply body, or may be fixed to a heat insulating member disposed between the power supply body and the heat dissipation part.

  According to the present invention, when the temperature of the power supply body is lower than the threshold value, heat dissipation of the power supply body can be suppressed. Thereby, the power supply output corresponding to a vehicle output can be obtained.

  Examples of the present invention will be described below.

  With reference to FIG. 1 and FIG. 2, a temperature control structure for a battery which is an embodiment of the present invention will be described. Here, FIG. 1 is a schematic view of a battery temperature control structure (during heat dissipation), (a) is a sectional view in the vertical direction, and (b) is a plan view. FIG. 2 is a vertical sectional view of the battery temperature control structure (when heat dissipation is suppressed).

  In these drawings, a battery (power source body) 12 is disposed at a position separated from a floor panel (vehicle heat dissipation part) 15, and a bimetal (heat transfer member) 13 is attached to the outer surface of the battery 12. .

  The bimetal 13 is fixed to the floor panel 15 and is deformed when the temperature is 40 ° C. or lower, thereby reducing the contact area with the battery 12 (see FIG. 2).

  Therefore, when the temperature of the battery 12 is higher than 40 ° C. (threshold), the heat of the battery 12 can be sufficiently dissipated through the bimetal 13 (see FIG. 1A). Thereby, progress of the battery deterioration of the battery 12 can be suppressed.

  On the other hand, when the temperature of the battery 12 is 40 ° C. or less, the contact area between the bimetal 13 and the battery 12 is reduced, so that heat dissipation of the battery 12 can be suppressed (see FIG. 2). Thereby, the battery output corresponding to the vehicle output can be obtained while suppressing the temperature drop of the battery 12.

Next, the temperature adjustment structure of the battery 12 will be described in detail.
(About battery 12)
The plurality of lithium ion batteries 122 are electrically connected by a bus bar (not shown) and are accommodated in the housing 121. The housing 121 is further filled with a cooling liquid so that the heat of the lithium ion battery 122 is transferred to the cooling liquid.

In the lithium ion battery 122, carbon (C) such as graphite can be used as the negative electrode active material, and lithium cobaltate (LiCoO ₂ ), lithium nickelate (LiNiO ₂ ), lithium manganate (LiMn ₂ ) as the positive electrode active material. O ₄ ) can be used.

As the cooling liquid, the specific heat, thermal conductivity and boiling point are high, and the casing 121, the lithium ion battery 12.
A material that does not corrode the outer tube 2 and is not susceptible to thermal decomposition, air oxidation, or electrolysis is suitable. Furthermore, an electrically insulating liquid is desirable in order to prevent a short circuit between the electrode terminals.
For example, a fluorinated inert liquid can be used. As the fluorine-based inert liquid, Fluorinert, Novec HFE (hydrofluorether), and Novec 1230 manufactured by 3M can be used. In addition, a liquid other than the fluorine-based inert liquid (for example, silicon oil) can be used.

  Stainless steel with high thermal conductivity can be used for the housing 121. Furthermore, a plurality of heat radiation fins (not shown) for promoting heat dissipation of the battery 12 can be provided on the upper surface and the lower surface of the housing 121.

(About bimetal 13)
The bimetal 13 is in contact with the outer surface (side surface) of the casing 121 of the battery 12, and the lower end portion of the bimetal 13 is fixed to the floor panel 15. Thus, by providing the bimetal 13 with the two functions of the heat transfer member during heat dissipation and the battery 12 fixing member, the cost can be reduced by reducing the number of components.

The bimetal 13 is attached to the region near the lower end of the side surface of the housing 121 using the fastening bolt 14. When the temperature is 40 ° C. or lower as shown in FIG. Further, the upper portion is deformed so as to be separated from the housing 121.

The bimetal 13 includes a first plate member 131 made of Al or Pb and an invar (Ni:
36% by mass, Fe: 64% by mass), and a second plate member 132 made of a laminate.

Thermally conductive grease is applied to the contact surface of the second plate member 132 with the housing 121. Here, as the thermally conductive grease, aluminum grease or silicon grease can be used.

As described above, by interposing the heat conductive grease between the second plate member 132 and the housing 121, the minute unevenness present on the contact surface of the second plate member 132 and the housing 121 is removed from the heat conductive grease. Can be filled with. Thereby, heat radiation from the battery 12 to the second plate member 132 can be promoted.

  Here, in this embodiment, the temperature at which the bimetal 13 is deformed, that is, the threshold value is set to 40 ° C., but the battery temperature necessary to obtain the battery output corresponding to the vehicle output is secured and the temperature rises. From the two viewpoints of suppressing the progress of the battery deterioration due to, it can be changed as appropriate.

  Next, a method for adjusting the temperature of the battery 12 will be described in detail. In the initial state, the battery temperature of the battery 12 is assumed to be raised to a temperature higher than 40 ° C. due to charge / discharge. In this case, the bimetal 13 is not deformed and is in contact with the entire side surface of the housing 121 (see FIG. 1).

  Therefore, the battery 12 can sufficiently dissipate heat through the bimetal 13. Thereby, the battery temperature of the battery 12 falls, and progress of battery deterioration can be suppressed.

  On the other hand, when the temperature of the battery 12 is lower than 40 ° C., the upper part of the bimetal 13 above the fastening hole of the fastening bolt 14 is deformed so as to be separated from the housing 121 (see FIG. 2). The contact area of the housing 121 is reduced. Thereby, it is possible to suppress the heat of the battery 12 from being radiated to the outside of the vehicle through the bimetal 13. As a result, a battery output can be obtained corresponding to the vehicle output.

  The battery 12 is disposed at a position separated from the floor panel 15, and an air layer is formed between the lower surface of the housing 121 and the floor panel 15. Therefore, it is possible to suppress the heat of the battery 12 from being transferred to the floor panel 15 from the lower surface of the housing 121.

  As described above, according to this embodiment, the battery 12 can be maintained at an appropriate temperature with a simple structure. Here, the appropriate temperature is a battery temperature that is considered to promote the progress of battery deterioration (in the case of a lithium ion battery, 60 ° C. can be exemplified) and a battery output corresponding to the vehicle output is obtained. It means a temperature between the battery temperature required for the battery (in the case of a lithium ion battery, −10 ° C. can be exemplified).

  Moreover, since the heater for heating up the battery 12 can be omitted, the cost can be reduced.

  Next, the temperature control structure of the battery of Example 2 will be described with reference to FIG. Here, FIG. 3 is a schematic diagram of the temperature adjustment structure of the battery of Example 2, (a) illustrates the state during heat dissipation, and (b) illustrates the state during heat dissipation suppression. . In addition, the part which has the same function as Example 1 is attached | subjected with the same code | symbol, and description is abbreviate | omitted.

  A heat insulating plate 21 is interposed between the battery 12 and the floor panel 15, and the bimetal 13 is attached to the heat insulating plate 21 using fastening bolts (fixing members) 14. As the heat insulating plate 21, a resin can be used.

  The heat insulating plate 21 corresponds to the heat insulating member described in the claims. Here, “heat insulation” includes not only the case where heat radiation is completely blocked, but also the case where heat is slightly radiated through the heat insulation plate 21. That is, it is only necessary to suppress heat dissipation to such an extent that a battery output corresponding to the vehicle output can be obtained.

According to the above-described configuration, when the temperature of the bimetal 13 is lower than 40 ° C., the bimetal 13 and the battery 12 can be completely brought into non-contact as illustrated in FIG. Thereby, the heat radiation from the bimetal 13 can be suppressed as compared with the configuration of the first embodiment.
(Other examples)
In each of the above-described embodiments, the bimetal 13 is used as the heat transfer member, but a shape memory alloy can also be used.

  The shape memory alloy may be any shape memory alloy having a restoring force based on thermoelastic martensitic transformation and reverse transformation such as nickel-titanium alloy and copper-zinc-aluminum alloy. The shape change temperature range in which the shape is restored to the shape restored by the formed shape can be changed by changing the heat treatment process appropriately selecting the shape memory alloy.

  In each of the above-described embodiments, the bimetal 13 is fixed using the fastening bolt 14, but may be fixed using another method. For example, the bimetal 13 may be fixed by winding a linear member such as a wire from above the bimetal 13.

  The present invention can also be applied to nickel-metal hydride batteries (power supply bodies) and electric double layer capacitors (power supply bodies). Here, the electric double layer capacitor is obtained by alternately stacking a plurality of positive electrodes and negative electrodes with a separator interposed therebetween. In this electric double layer capacitor, for example, an aluminum foil as a current collector, activated carbon as a positive electrode active material and a negative electrode active material, and a porous film made of polyethylene as a separator can be used.

  The present invention can also be applied to a prismatic battery (power supply body).

It is the schematic of the temperature control structure (at the time of heat dissipation) of a battery, (a) is sectional drawing of an up-down direction, (b) is a top view. It is sectional drawing of the up-down direction of the temperature control structure (at the time of heat dissipation suppression) of a battery. It is the schematic of the temperature control structure of the battery of Example 2, (a) has illustrated the state at the time of heat radiation, (b) has illustrated the state at the time of heat dissipation suppression.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Battery 13 Bimetal 14 Fastening bolt 15 Floor panel 21 Heat insulation plate 121 Case 122 Lithium ion battery 131 1st board member 132 2nd board member

Claims (6)

A power supply body disposed at a position away from the heat dissipation part of the vehicle;
A heat transfer member for contacting the power supply body and transferring heat of the power supply body to the heat radiating portion;
The heat transfer member is disposed at a position sandwiching the power supply body. When the temperature becomes lower than a threshold value, the heat transfer member is deformed so as to reduce a contact area with the power supply body, and the heat dissipation member is contacted with the power supply body. A temperature control structure for a power supply unit, wherein an extension portion extending toward the unit functions as a bracket for fixing the power supply unit to the heat dissipation unit by being fixed to the heat dissipation unit.   The temperature control structure of a power source body according to claim 1, wherein the heat transfer member is a bimetal or a shape memory alloy.   The temperature control structure of a power supply body according to claim 1 or 2, wherein thermally conductive grease is applied to a contact surface of the heat transfer member and the power supply body.   The temperature control structure of a power supply unit according to any one of claims 1 to 3, wherein the heat transfer member is fixed to the power supply unit.   It has the heat insulation member arrange | positioned between the said power supply body and the said thermal radiation part, The said heat transfer member was fixed to the said heat insulation member, The Claim 1 characterized by the above-mentioned. Power supply temperature control structure.   The vehicle which has the temperature control structure of the power supply body as described in any one of Claims 1 thru | or 5.

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