JP2008001309A - Vehicle underfloor structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a vehicular underfloor structure capable of suppressing the temperature rise around an exhaust system by a simple constitution. <P>SOLUTION: In the vehicular underfloor structure 10, a latent heat storage device 28 is arranged between a floor panel 14 and an under-cover 26 facing an exhaust system 22. Thus, even when an exhaust gas passes through the exhaust system 22, the exhaust device 22 is heated thereby, and the heat is radiated from the exhaust system 22, the heat radiated from the exhaust system 22 is stored with the latent heat by the latent heat storage device 28. Any temperature rise around the exhaust system 22 is suppressed thereby. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a vehicle underfloor structure, and more particularly, to a vehicle underfloor structure configured with an under cover at a lower portion of a vehicle body.

Conventionally, the following is known as this kind of vehicle under floor structure (for example, refer to patent documents 1). For example, Patent Document 1 discloses an example of a vehicle undercover device. In the example described in Patent Document 1, an under cover that covers the floor panel and the exhaust device from below is provided at the lower portion of the vehicle body. Further, the under cover is provided with a slit and a slide type cover for promoting cooling around the exhaust device.
JP-A-7-215074

  However, in the example described in Patent Document 1, it is necessary to drive the slide type cover in order to open and close the slit provided in the under cover. For this reason, a drive mechanism for driving the slide type cover is required.

  The present invention has been made in view of the above circumstances, and an object thereof is to suppress a temperature rise around the exhaust device with a simpler configuration.

  In order to solve the above-described problem, the vehicle underfloor structure according to claim 1 includes a floor panel provided at a lower part of a vehicle body, an exhaust unit provided below the floor panel and extending from an engine, And a latent heat storage means arranged to face the exhaust means below the floor panel.

  In the vehicle underfloor structure according to the first aspect, the latent heat storage means is disposed so as to face the exhaust means below the floor panel. Therefore, even if the exhaust means is heated by passing the exhaust gas through the exhaust means and heat is released from the exhaust means, the heat released from the exhaust means is stored as latent heat by the latent heat storage means. Thereby, the temperature rise around the exhaust means can be suppressed.

  As described above, according to the vehicle underfloor structure of the first aspect, the temperature around the exhaust unit can be reduced by a simple configuration in which the latent heat storage unit is disposed so as to face the exhaust unit below the floor panel. The rise can be suppressed.

  The vehicle underfloor structure according to claim 2 is the vehicle underfloor structure according to claim 1, further comprising an under cover below the exhaust means, and between the floor panel and the under cover as the vehicle travels. An air flow can be formed.

  In the vehicle underfloor structure according to the second aspect, an under cover is provided below the exhaust means, and an air flow is formed between the floor panel and the under cover as the vehicle travels. Therefore, when the vehicle travels, an air flow is formed between the floor panel and the under cover, and the periphery of the exhaust means is cooled by this air flow. Thereby, the temperature rise around the exhaust means can be suppressed as the vehicle travels.

  The vehicle underfloor structure according to claim 3 is the vehicle underfloor structure according to claim 1 or 2, wherein the latent heat storage means is disposed between the floor panel and the exhaust means. And

  In the vehicle underfloor structure according to claim 3, the latent heat storage means is arranged between the floor panel and the exhaust means. Therefore, even when heat is released from the exhaust means to the floor panel side, this heat is stored as latent heat by the latent heat storage means. Thereby, the temperature rise of a floor panel can also be suppressed.

  The vehicle underfloor structure according to claim 4 is the vehicle underfloor structure according to claim 3, wherein the latent heat storage means includes a latent heat storage material and a container in which the latent heat storage material is enclosed, A first facing surface facing the floor panel; and a second facing surface facing the exhaust means and made of a material having a higher thermal emissivity than the first facing surface. It is characterized by.

  In the vehicle underfloor structure according to claim 4, the latent heat storage means includes a latent heat storage material and a container in which the latent heat storage material is sealed, and a second facing surface facing the exhaust means of the container has a floor It is comprised with the material whose heat emissivity is higher than the 1st opposing surface which opposes a panel. Here, in general, a material having a high thermal emissivity is a material having a high heat absorption rate at the same time. Therefore, as described above, if the second facing surface facing the exhaust means is made of a material having a high thermal emissivity, the heat released from the exhaust means is transferred to the latent heat storage material via the second facing surface. You can store quickly. Thereby, the temperature rise around the exhaust means can be more reliably suppressed.

  Moreover, the 1st opposing surface which opposes a floor panel is comprised with the material whose heat emissivity is lower than the 2nd opposing surface in other words. Therefore, in the heat dissipation process of the latent heat storage material, the amount of heat released to the floor panel can be reduced as compared with the case where the entire container is made of the material having the same thermal emissivity. Thereby, the temperature rise of the floor panel in the heat dissipation process of the latent heat storage material can be more reliably suppressed.

  The vehicle underfloor structure according to claim 5 is the vehicle underfloor structure according to claim 1 or 2, further comprising an under cover below the exhaust means, wherein the latent heat storage means includes the exhaust means and the under cover. It is arrange | positioned between covers.

  In the vehicle underfloor structure according to the fifth aspect, the latent heat storage means is disposed between the exhaust means and the under cover. Therefore, the heat released downward from the exhaust means, that is, to the under cover side can be stored by the latent heat by the latent heat storage means.

  The vehicle underfloor structure according to claim 6 is the vehicle underfloor structure according to claim 5, which is disposed between the floor panel and the exhaust means, and the heat released from the exhaust means is transferred to the latent heat storage means side. It is characterized by comprising a heat reflecting material capable of reflecting toward the surface.

  In the vehicle underfloor structure according to the sixth aspect, a heat reflecting material capable of reflecting the heat released from the exhaust means to the latent heat storage means side is disposed between the floor panel and the exhaust means. Therefore, the heat released from the exhaust means to the floor panel side can be reflected to the latent heat storage means side by the heat reflecting material. Thereby, the temperature rise of a floor panel can be suppressed. Further, heat from the exhaust means to the floor panel side can be prevented, and heat from the exhaust means can be efficiently stored by the latent heat storage means.

  The vehicle underfloor structure according to claim 7 is the vehicle underfloor structure according to claim 5, wherein the latent heat storage means is disposed in contact with the under cover.

  In the vehicle underfloor structure according to the seventh aspect, the latent heat storage means is disposed in contact with the under cover. Therefore, in the heat release process of the latent heat storage means, the heat from the latent heat storage means can be released to the outside through the wide surface of the under cover.

  The vehicle underfloor structure according to an eighth aspect is the vehicle underfloor structure according to the first to seventh aspects, further comprising an under cover below the exhaust means, and the under cover is provided with a heat radiating means. It is characterized by being.

  In the vehicle underfloor structure according to the eighth aspect, the under cover is provided with a heat dissipating means. Therefore, the heat from the latent heat storage means can be released to the outside more efficiently through the wide surface of the under cover.

  As described above in detail, according to the present invention, it is possible to suppress the temperature rise around the exhaust means with a simpler configuration.

[First embodiment]
First, a first embodiment of the present invention will be described with reference to FIGS.

  FIG. 1 is a perspective view of a vehicle 12 to which a vehicle underfloor structure 10 according to the first embodiment of the present invention is applied, and FIG. 2 is a sectional view taken along line 2-2 of FIG. In these drawings, the arrow Fr indicates the vehicle front-rear direction front side, the arrow Up indicates the vehicle vertical direction upper side, and the arrow Out indicates the vehicle width direction outer side.

  As shown in FIG. 1, the vehicle underfloor structure 10 according to the first embodiment of the present invention is suitably equipped on a vehicle 12 such as a passenger car, for example. In the vehicle 12 to which the vehicle underfloor structure 10 according to the first embodiment of the present invention is applied, for example, as shown in FIG. 2 which is a sectional view taken along line 2-2 in FIG. Is provided. The floor panel 14 is provided with a tunnel portion 16 at the center in the vehicle width direction along the vehicle front-rear direction. The tunnel portion 16 is configured to be recessed from the lower side to the upper side and open to the lower side.

  In the present embodiment, the floor panel 14 includes flat portions 18 on both sides of the tunnel portion 16. The flat portion 18 is provided with a reinforcement 20 along the vehicle longitudinal direction.

  In the vehicle 12, an exhaust device 22 is disposed inside the tunnel portion 16. The exhaust device 22 extends in the vehicle front-rear direction along the tunnel portion 16. The exhaust device 22 has a front end connected to an engine provided at the front of the vehicle body, and a rear end configured as an exhaust port through which exhaust gas can be discharged. Although not particularly shown, the exhaust device 22 includes a plurality of exhaust pipes 24, a catalyst, a muffler, a tail pipe, and the like.

  Further, in the vehicle 12, as shown in FIGS. 1 and 2, an under cover 26 is provided at the lower portion of the vehicle body. The under cover 26 is for reducing the air resistance at the lower part of the vehicle body when the vehicle is running, and is made of a flat plate material that covers the entire floor panel 14 shown in FIG. As shown in FIG. 2, the under cover 26 is provided so as to cover the floor panel 14 and the exhaust device 22 provided below the floor panel 14 from below. The under cover 26 is made of a material having a high melting point, a flame retardant property, and a high thermal emissivity, for example, high heat dissipation aluminum.

  And in the vehicle 12 comprised with this under cover 26, it is set as the structure which a driving | running | working wind passes a vehicle body as follows with driving | running | working. That is, as the vehicle travels, traveling wind is taken into the engine compartment from the front grille at the front of the vehicle body, and this traveling wind is taken between the floor panel 14 and the under cover 26 after passing through the engine compartment, and then the underwind is taken. The cover 26 is configured to be discharged rearward from the vehicle.

  Further, in the vehicle 12, for example, as shown in FIG. 2 which is a sectional view taken along line 2-2 in FIG. 1, a latent heat storage device 28 is provided between the floor panel 14 and the exhaust device 22 (exhaust pipe 24). ing. The latent heat storage device 28 is formed in a circular arc shape surrounding the upper side of the exhaust device 22, and is disposed so as to face the exhaust device 22 in the radial direction. The latent heat storage device 28 extends in the vehicle front-rear direction along the exhaust device 22.

  In the present embodiment, the latent heat storage device 28 is configured such that the latent heat storage material 32 is enclosed in a hollow container 30. As the latent heat storage material 32, a material capable of storing heat as latent heat by melting is preferably used. For example, inorganic hydrate salts such as sodium acetate hydrate and calcium chloride hydrate, or paraffin Various sugar alcohols are preferably used.

  In addition, the container 30 of the latent heat storage device 28 is configured to be divided into an upper case 30 </ b> A and an upper case 30 </ b> A disposed facing the floor panel 14 and a lower case 30 </ b> B disposed facing the exhaust device 22. ing. The entire container 30 constituted by the upper case 30A and the lower case 30B is made of, for example, aluminum from the viewpoint of weight reduction, but the upper case 30A is made of a material having a low thermal emissivity, The lower case 30B is made of a material (for example, high heat dissipation aluminum) having a higher thermal emissivity than the upper case 30A.

  Next, the operation of the vehicle underfloor structure 10 according to the first embodiment of the present invention will be described.

  In the configuration described above, when the vehicle is traveling, traveling wind is taken into the engine compartment from the front grille at the front of the vehicle body, and this running wind is taken between the floor panel 14 and the under cover 26 after passing through the engine compartment. Then, it is discharged from the rear end of the under cover 26 to the rear of the vehicle.

  Accordingly, since an air flow exists between the floor panel 14 and the under cover 26, the exhaust device 22 is heated when the exhaust gas passes through the exhaust device 22, and heat is released from the exhaust device 22. Even in this case, the heat released from the exhaust device 22 is cooled by the air flow. Thereby, the temperature rise of the components around the floor panel 14 and the exhaust device 22 is suppressed, and the components around the floor panel 14 and the exhaust device 22 are prevented from being overheated.

  Even when the vehicle 12 is stopped after traveling and the engine is started, the air flow between the floor panel 14 and the under cover 26 is maintained by the operation of the radiator fan in the engine compartment. Therefore, the heat released from the exhaust device 22 is cooled by the air flow as in the case of traveling of the vehicle. Thereby, the temperature rise of the components around the floor panel 14 and the exhaust device 22 is suppressed, and the components around the floor panel 14 and the exhaust device 22 are prevented from being overheated.

  On the other hand, in the state where the vehicle 12 is stopped after traveling and the engine is also stopped, the air flow between the floor panel 14 and the under cover 26 does not occur with the operation of the radiator fan in the engine compartment stopped. Therefore, heat is generated by radiation and convection from the exhaust device 22 in a high temperature state.

  However, in the present embodiment, as described above, the heat released from the exhaust device 22 is absorbed by the latent heat storage device 28 disposed around the exhaust device 22. That is, when the heat is transferred to the latent heat storage material 32 held in the latent heat storage device 28 and the temperature of the latent heat storage material 32 rises and reaches the melting point of the latent heat storage material 32, the latent heat storage device 28. While storing the latent heat storage material 32, heat is stored in the form of latent heat of fusion. Therefore, most of the heat released from the exhaust device 22 is stored in the latent heat storage material 32. As a result, the temperature rise of the components around the floor panel 14 and the exhaust device 22 is suppressed and the components around the floor panel 14 and the exhaust device 22 are prevented from being overheated, as in the case of traveling the vehicle. .

  In particular, in the present embodiment, the lower case 30B facing the exhaust device 22 of the container 30 provided in the latent heat storage device 28 is made of a material having a high thermal emissivity. Here, in general, a material having a high thermal emissivity is a material having a high heat absorption rate at the same time. Therefore, as described above, if the lower case 30B facing the exhaust device 22 is made of a material having a high thermal emissivity, the heat released from the exhaust device 22 is transferred to the latent heat storage material 32 via the lower case 30B. Can be stored more quickly. Thereby, the temperature rise around the exhaust device 22 can be more reliably suppressed.

  In the present embodiment, the latent heat storage device 28 is disposed between the floor panel 14 and the exhaust device 22. Therefore, even when heat is released from the exhaust device 22 to the floor panel 14, this heat can be stored by the latent heat storage device 28. Thereby, the temperature rise of the floor panel 14 can be suppressed more reliably.

  As described above, the heat stored in the latent heat storage device 28 is released along with the solidification when the temperature of the latent heat storage material 32 decreases and reaches the freezing point. At this time, if the vehicle 12 is in a running state, the latent heat storage device 28 that has stored heat as described above is cooled by the air flow that exists between the floor panel 14 and the under cover 26. For this reason, the heat | fever discharge | released from the latent-heat storage device 28 does not overheat the floor panel 14 and the components around the exhaust device 22.

  Further, even when the vehicle 12 is stopped, the heat release from the latent heat storage material 32 gradually proceeds as a characteristic of the latent heat storage material 32. For this reason, the temperature rise of the parts around the floor panel 14 and the exhaust device 22 is moderate, and the parts around the floor panel 14 and the exhaust device 22 are not overheated even by natural cooling.

  In particular, in this embodiment, the material of the lower case 30B disposed to face the exhaust device 22 is made of a material having a higher heat emissivity than the upper case 30A, that is, for example, high heat dissipation aluminum. Accordingly, it is possible to direct the radiant heat from the latent heat storage device 28 toward the exhaust device 22 having generally high heat resistance. In this embodiment, the under cover 26 below the exhaust device 22 is also made of high heat dissipation aluminum. Therefore, as described above, the radiant heat from the latent heat storage device 28 to the exhaust device 22 can be released to the ground side with little influence on the vehicle 12. Thereby, the temperature rise of the components around the exhaust device 22 in the heat release process of the latent heat storage material 32 can be more reliably suppressed.

  In the present embodiment, the upper case 30A facing the floor panel 14 of the container 30 provided in the latent heat storage device 28 is made of a material having a low thermal emissivity. Therefore, as described above, in the heat dissipation process of the latent heat storage material 32, the amount of heat released to the floor panel 14 can be reduced as compared with the case where the entire container 30 is made of the material having the same thermal emissivity. . Thereby, the temperature rise of the floor panel 14 in the heat dissipation process of the latent heat storage material 32 can be more reliably suppressed.

  As described above, according to the vehicle underfloor structure 10 according to the first embodiment of the present invention, the latent heat storage device 28 is simply disposed between the floor panel 14 and the under cover 26 so as to face the exhaust device 22. With this simple configuration, it is possible to suppress the temperature rise of the components around the floor panel 14 and the exhaust device 22.

  Further, as described above, even if the entire floor panel 14 and the exhaust device 22 are covered with the under cover 26, it is possible to prevent the peripheral components of the floor panel 14 and the exhaust device 22 from being overheated by the heat released from the exhaust device 22. In addition, the under cover 26 can significantly reduce the air resistance at the bottom of the vehicle body when the vehicle is traveling.

  In the present embodiment, the latent heat storage device 28 is configured to be covered with the under cover 26 from below. Therefore, it is possible to prevent the latent heat storage device 28 from becoming dirty or damaged as the vehicle travels. Thereby, it can prevent that the heat storage performance of the latent heat storage apparatus 28 falls with vehicle travel.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG.

  FIG. 3 is a cross-sectional view of the lower portion of the vehicle 42 to which the vehicle underfloor structure 40 according to the second embodiment of the present invention is applied. In this figure, the arrow Up indicates the vehicle vertical direction upper side, and the arrow Out indicates the vehicle width direction outer side.

  The vehicle underfloor structure 40 according to the first embodiment of the present invention has a configuration changed as follows with respect to the vehicle underfloor structure 10 according to the first embodiment of the present invention described above. Therefore, in the second embodiment of the present invention, a configuration different from that of the first embodiment described above will be described, and the description of the same configuration will be omitted by using the same reference numerals.

  In the vehicle 42 to which the vehicle underfloor structure 40 according to the second embodiment of the present invention is applied, a latent heat storage device 48 is disposed between the exhaust device 22 (exhaust pipe 24) and the under cover 26. The latent heat storage device 48 is configured in a flat plate shape facing the exhaust device 22 on the lower side of the exhaust device 22. The latent heat storage device 48 extends in the vehicle front-rear direction along the exhaust device 22. Further, the latent heat storage device 48 is disposed in contact with the upper surface of the under cover 26.

  In the present embodiment, the latent heat storage device 48 is configured such that a latent heat storage material 52 is enclosed in a hollow container 50. As the latent heat storage material 52, similarly to the latent heat storage material 32 of the first embodiment, a material capable of storing heat as latent heat by melting is preferably used. For example, sodium acetate hydrate or calcium chloride Inorganic hydrated salts such as hydrates, paraffin, various sugar alcohols and the like are preferably used.

  In the vehicle 42, a heat reflecting material 54 is disposed between the floor panel 14 and the exhaust device 22. The heat reflecting material 54 is configured by making a flat plate made of aluminum into a circular arc shape, and is disposed to face the exhaust device 22 in a radial direction so as to surround the upper side of the exhaust device 22. With this configuration, the heat reflecting material 54 can reflect the heat released from the exhaust device 22 to the latent heat storage device 48 side.

  Next, the operation of the vehicle underfloor structure 40 according to the second embodiment of the present invention will be described.

  In the configuration described above, when the vehicle is traveling, traveling wind is taken into the engine compartment from the front grille at the front of the vehicle body, and this running wind is taken between the floor panel 14 and the under cover 26 after passing through the engine compartment. Then, it is discharged from the rear end of the under cover 26 to the rear of the vehicle.

  Accordingly, since an air flow exists between the floor panel 14 and the under cover 26, the exhaust device 22 is heated when the exhaust gas passes through the exhaust device 22, and heat is released from the exhaust device 22. Even in this case, the heat released from the exhaust device 22 is cooled by the air flow. Thereby, the temperature rise of the components around the floor panel 14 and the exhaust device 22 is suppressed, and the components around the floor panel 14 and the exhaust device 22 are prevented from being overheated.

  Further, even when the vehicle 42 is stopped after traveling and the engine is started, the air flow between the floor panel 14 and the under cover 26 is maintained by the operation of the radiator fan in the engine compartment. Therefore, the heat released from the exhaust device 22 is cooled by the air flow as in the case of traveling of the vehicle. Thereby, the temperature rise of the components around the floor panel 14 and the exhaust device 22 is suppressed, and the components around the floor panel 14 and the exhaust device 22 are prevented from being overheated.

  On the other hand, in a state where the vehicle 42 is stopped after traveling and the engine is also stopped, an air flow between the floor panel 14 and the under cover 26 does not occur with the operation of the radiator fan in the engine compartment being stopped. Therefore, heat is generated by radiation and convection from the exhaust device 22 in a high temperature state.

  However, in the present embodiment, as described above, the heat released downward from the exhaust device 22 directly reaches the latent heat storage device 48 disposed below the exhaust device 22. Further, the heat released from the exhaust device 22 to the floor panel 14 side is reflected by the heat reflecting material 54 toward the latent heat storage device 48 side and reaches the latent heat storage device 48.

  In this way, when the heat released from the exhaust device 22 reaches the latent heat storage device 48, the heat is transmitted to the latent heat storage material 52 held in the latent heat storage device 48, and latent heat storage is performed. When the temperature of the material 52 rises and reaches the melting point of the latent heat storage material 52, the latent heat storage device 48 stores heat in the form of latent heat of fusion while melting the latent heat storage material 52. Therefore, most of the heat released from the exhaust device 22 is stored in the latent heat storage material 52. As a result, the temperature rise of the components around the floor panel 14 and the exhaust device 22 is suppressed and the components around the floor panel 14 and the exhaust device 22 are prevented from being overheated, as in the case of traveling the vehicle. .

  In particular, in the present embodiment, the heat released from the exhaust device 22 to the floor panel 14 side can be reflected to the latent heat storage device 48 side by the heat reflecting material 54. Thereby, the temperature rise of the floor panel 14 can be suppressed reliably. Further, heat from the exhaust device 22 to the floor panel 14 side can be prevented, and the heat from the exhaust device 22 can be efficiently stored by the latent heat storage device 48.

  As described above, the heat stored in the latent heat storage device 48 is released along with the solidification when the temperature of the latent heat storage material 52 decreases and reaches the freezing point. At this time, if the vehicle 42 is in a running state, the latent heat storage device 48 that has stored heat as described above is cooled by the air flow that exists between the floor panel 14 and the under cover 26. For this reason, the heat | fever discharge | released from the latent heat storage apparatus 48 does not overheat the floor panel 14 and the peripheral component of the exhaust apparatus 22. FIG.

  Further, even when the vehicle 42 is stopped, the heat release from the latent heat storage material 52 gradually proceeds as a characteristic of the latent heat storage material 52. For this reason, the temperature rise of the parts around the floor panel 14 and the exhaust device 22 is moderate, and the parts around the floor panel 14 and the exhaust device 22 are not overheated even by natural cooling.

  In the present embodiment, the latent heat storage device 48 is disposed in contact with the under cover 26. Therefore, in the heat release process of the latent heat storage device 48, the heat from the latent heat storage device 48 can be released to the outside through the wide surface of the under cover 26.

  As described above, according to the vehicle underfloor structure 40 according to the second embodiment of the present invention, the latent heat storage device 48 is simply disposed between the floor panel 14 and the under cover 26 so as to face the exhaust device 22. With this simple configuration, it is possible to suppress the temperature rise of the components around the floor panel 14 and the exhaust device 22.

  Further, as described above, even if the entire floor panel 14 and the exhaust device 22 are covered with the under cover 26, it is possible to prevent the peripheral components of the floor panel 14 and the exhaust device 22 from being overheated by the heat released from the exhaust device 22. In addition, the under cover 26 can significantly reduce the air resistance at the bottom of the vehicle body when the vehicle is traveling.

  In the present embodiment, the latent heat storage device 48 is configured to be covered with the under cover 26 from below. Accordingly, it is possible to prevent the latent heat storage device 48 from becoming dirty or damaged as the vehicle travels. Thereby, it can prevent that the thermal storage performance of the latent heat storage apparatus 48 falls with vehicle travel.

  Next, a modified example of the vehicle underfloor structures 10 and 40 according to the present embodiment will be described with reference to FIG.

  In each of the above embodiments, the under cover 26 is described as being configured in a flat plate shape, but may be as follows. That is, as shown in FIG. 4, heat radiation fins 56 extending in the vehicle front-rear direction may be provided on the lower surface of the under cover 26. In this case, by providing the heat radiation fins 56, the lower surface of the under cover 26 becomes uneven, and the surface area thereof is increased. Therefore, the heat radiation efficiency from the under cover 26 can be increased.

1 is a perspective view of a vehicle to which a vehicle underfloor structure according to a first embodiment of the present invention is applied. FIG. 2 is a sectional view taken along line 2-2 of FIG. It is sectional drawing of the lower part of the vehicle to which the vehicle underfloor structure which concerns on 2nd embodiment of this invention was applied. It is a perspective view which shows the modification of the undercover provided in the vehicle underfloor structure which concerns on this embodiment.

Explanation of symbols

10, 40 Vehicle underfloor structure 14 Floor panel 22 Exhaust device (exhaust means)
24 Exhaust pipe 26 Undercover 28, 48 Latent heat storage device (latent heat storage means)
30, 50 Container 30A Upper case (first facing surface)
30B Lower case (second facing surface)
32, 52 Latent heat storage material 54 Heat reflection material 56 Radiation fin (heat radiation means)

Claims (8)

A floor panel provided at the bottom of the car body,
Exhaust means provided below the floor panel and extending from the engine,
Latent heat heat storage means arranged to face the exhaust means below the floor panel;
A vehicle underfloor structure characterized by comprising: An under cover is provided below the exhaust means,
The vehicle underfloor structure according to claim 1, wherein an air flow can be formed between the floor panel and the under cover as the vehicle travels.   The vehicle underfloor structure according to claim 1 or 2, wherein the latent heat storage means is disposed between the floor panel and the exhaust means. The latent heat storage means is
Latent heat storage material,
A container in which the latent heat storage material is enclosed;
With
The container is
A first facing surface facing the floor panel;
A second facing surface made of a material facing the exhaust means and having a higher thermal emissivity than the first facing surface;
The vehicle underfloor structure according to claim 3, wherein the vehicle underfloor structure is provided. An under cover is provided below the exhaust means,
The vehicle underfloor structure according to claim 1 or 2, wherein the latent heat storage means is disposed between the exhaust means and the under cover.   The vehicle according to claim 5, further comprising a heat reflecting material disposed between the floor panel and the exhaust unit and capable of reflecting the heat released from the exhaust unit to the latent heat storage unit side. Underfloor structure.   The vehicle underfloor structure according to claim 5 or 6, wherein the latent heat storage means is disposed in contact with the under cover. An under cover is provided below the exhaust means,
The vehicle underfloor structure according to any one of claims 1 to 7, wherein the under cover is provided with a heat dissipating means.

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