Heat shield device

Abstract

The present invention provides a heat shield device comprising a first unit 1, a second unit 2, and a central exhaust pipe 8 disposed between the first unit 1 and the second unit 2, and comprising a first heat shield panel 11 fixed to the first unit 1 and disposed on the central exhaust pipe 8 side and a second heat shield panel 12 fixed to the second unit 2 and disposed on the central exhaust pipe 8 side, the first heat shield panel 11 and the second heat shield panel 12 having extension sections 11A, 12A above the central exhaust pipe 8 which overhang at different heights and overlap each other at tip portions when in top-down vehicular view. The first and second units 1, 2 are not influenced by vibrations from the individual units, and the units 1, 2 disposed around the central exhaust pipe 8 are protected from heat damage from the central exhaust pipe 8.

Description

Heat shielding device

[0001] The present invention relates to a heat shield device used in vehicles such as automobiles, and more particularly to a heat shield device used to protect units such as a drive source and a battery from the heat of an exhaust pipe.

[0002] A conventional heat shield device as described above is described, for example, in Patent Document 1. Patent Document 1 describes a cooling structure for a generator unit for a range extender vehicle that includes a generator engine that supplies power to the vehicle and a muffler through which exhaust gas from the generator engine flows.

[0003] The generator engine has a cylinder case and a cooling fan that introduces air into the cylinder case, and an opening is provided in the wall of the cylinder case to exhaust the air inside the cylinder case. The muffler has a muffler body through which exhaust gas flows and a cover member formed of a heat shield that covers the muffler body, and a communication passage part is provided between the cover member and the cylinder case. The cooling structure is configured so that air taken in by the cooling fan flows through the cylinder case and the communication passage part into the cover member and is exhausted to the outside.

[0004] Japanese Patent Application Publication No. 2021-41833

[0005] In a vehicle, each unit, such as the body, engine, motor, battery, frame, and drivetrain, is combined with cushioning materials to absorb individual vibrations. In contrast, in the conventional cooling structure described above, all of the cooling system passages are connected, so it is necessary to separate the cooling passages for each unit, which can lead to heat damage due to heat leakage.

[0006] The present invention has been made in consideration of the above-mentioned conventional situation, and aims to provide a heat-shielding device that can protect the first and second units arranged around the exhaust pipe from heat damage caused by the exhaust pipe without being affected by the individual vibrations of each unit, in particular in a structure that has a first unit that is swingably mounted on the vehicle body, a second unit fixed to the vehicle body, and an exhaust pipe arranged between the first and second units.

[0007] The heat shield device of the present invention includes a first unit swingably mounted on the vehicle body, a second unit disposed adjacent to the first unit and fixed to the vehicle body, and an exhaust pipe disposed between the first and second units. The heat shield device also includes a first heat shield plate fixed to the first unit and disposed on the exhaust pipe side of the first unit, and a second heat shield plate fixed to the second unit and disposed on the exhaust pipe side of the second unit. The heat shield device is characterized in that the first heat shield plate and the second heat shield plate have extensions that protrude above the exhaust pipe at different heights and whose tip portions overlap when viewed from above the vehicle.

[0008] The heat-shielding device of the present invention adopts the above-mentioned configuration, and in a structure having a first unit that is swingably mounted on the vehicle body, a second unit fixed to the vehicle body, and an exhaust pipe arranged between the first and second units, the first and second units arranged around the exhaust pipe can be protected from thermal damage by the exhaust pipe without being affected by the individual vibrations of each unit.

[0009] The present invention relates to a heat shield device and a vehicle underside, and a heat shield device for a vehicle that is in a stopped state.

[0010] <First embodiment> A vehicle V shown in FIG. 1 has a frame F and front, rear, left, and right wheels W, and also has a first unit 1 that is swingable relative to the vehicle body, a second unit 2 that is arranged adjacent to the first unit 1 and fixed to the vehicle body, an auxiliary motor 3 that is another unit arranged behind the second unit 2, and an inverter 4.

[0011] The first unit 1 is located at the front of the vehicle body and is specifically a drive source that integrates an engine and a main motor. The second unit 2 is located at the rear of the vehicle body and is specifically a battery. The engine may be used for either power generation or driving. The inverter 4 drives and controls the auxiliary motor 3 and the main motor. For this reason, the first unit 1, the second unit 2, and the inverter 4 are connected to each other by a high-voltage harness 5 shown by the dotted line in the figure.

[0012] Here, the first unit 1 is not provided to swing significantly relative to the vehicle body, but generates vibrations by itself like a drive source including an engine. For this reason, the first unit 1 is provided to be swingable relative to the vehicle body so as to tolerate vibrations received during driving and vibrations generated by itself.

[0013] The vehicle V is equipped with engine exhaust manifolds 1L, 1R on the left and right sides of the first unit (drive source) 1, as well as a side exhaust pipe 6 and a muffler 7 that communicate with the right manifold 1R along the right side of the vehicle body, and a central exhaust pipe 8 that connects the left manifold 1L and the side exhaust pipe 6 between the first unit 1 and the second unit 2. In other words, the exhaust pipe of the heat shield device according to the present invention is the central exhaust pipe 8 in this embodiment, which discharges exhaust gas from the first unit 1, which is the drive source including the engine.

[0014] 2 and 3, the heat shield device in the vehicle V described above includes a first heat shield plate 11 disposed between the first unit 1 and the central exhaust pipe 8, and a second heat shield plate 12 disposed between the second unit 2 and the central exhaust pipe 8. The first heat shield plate 11 is disposed on the front side of the vehicle body, and the second heat shield plate 12 is disposed on the rear side of the vehicle body. The first heat shield plate 11 and the second heat shield plate 12 extend in the left-right direction of the vehicle, and are configured such that the distance L2 between the second heat shield plate 12 and the central exhaust pipe 8 is greater than the distance L1 between the first heat shield plate 11 and the central exhaust pipe 8.

[0015] The first heat shield 11 has length and width dimensions corresponding to at least the height and length of the central exhaust pipe 8, and is fixed to the first unit 1 via connecting parts 13A and 13B, as shown in Figure 2. On the other hand, the second heat shield 12 also has length and width dimensions corresponding to at least the height and length of the central exhaust pipe 8, and is fixed to the second unit 2.

[0016] As a result, the first heat shield 11 is integrated with the first unit 1, which oscillates relative to the vehicle body, and is therefore not directly affected by vibrations of units other than the first unit 1. On the other hand, the second heat shield 12 is similarly integrated with the second unit 2, which is fixed to the vehicle body, and is therefore not directly affected by vibrations of units other than the second unit 2.

[0017] 3, a tunnel portion T extending in the fore-and-aft direction of the vehicle is formed between the first heat shield 11 and the second heat shield 12 and the floor panel P of the vehicle body B. The vehicle V of this embodiment has a structure without a propeller shaft and can run on either the first unit 1 or the auxiliary motor 3. The underside of the floor panel P is covered with a heat shield (not shown). The high-voltage harness 5 described above is disposed in the tunnel portion T, which is the space between the first unit 1 and the second unit 2 and the vehicle body B.

[0018] 3, the first heat shield plate 11 and the second heat shield plate 12 have extensions 11A, 12A that protrude above the central exhaust pipe 8 at different heights and whose tip portions overlap when viewed from above the vehicle body. The heat shield device forms a flow passage 14 between the first heat shield plate 11 and the second heat shield plate 12, which runs from the upper side, passes beside the central exhaust pipe 8, and is open to the underside of the vehicle.

[0019] In the heat shield device of this embodiment, the extension 11A of the first heat shield plate 11 is positioned lower than the extension 12A of the second heat shield plate 12, and has an extension length that covers the upper surface of the central exhaust pipe 8. The lower surface of the extension 11A of the first heat shield plate 11 faces the upper surface of the central exhaust pipe 8 with a space between them.

[0020] The first heat shield 11 in the illustrated example has an extension 11A in its middle portion, and its upper end is located higher than the upper end of the second heat shield 12. In contrast, the second heat shield 12 has an extension 12A at its upper end, and its lower end is located lower than the lower end of the first heat shield 11. Furthermore, the extensions 11A, 12A of the first heat shield 11 and the second heat shield 12 each have downward flanges 11B, 12B at their respective tips.

[0021] The flange portion 11B of the extension portion 11A of the first heat shield 11 forms an obtuse angle with the main body of the extension portion 11A. This flange portion 11B may be bent at a predetermined angle as in the illustrated example, or may have a curved surface that is continuous with the main body. On the other hand, the flange portion 12B of the extension portion 12A of the second heat shield 12 forms an angle with the main body of the extension portion 12A that is smaller than the obtuse angle, and more preferably forms a right angle or acute angle, and in the illustrated example forms a right angle.

[0022] 3, the heat shield device of the vehicle V of this embodiment is configured such that the ground clearance H2 of the second unit 2 is lower than the ground clearance H1 of the first unit 1 above the ground G. In contrast, the heat shield device has a central exhaust pipe 8 on its lower part (lower surface) that has an inclined surface 8A that slopes downward from the first unit 1 side to the second unit 2 side.

[0023] In the heat shield device having the above configuration, while the vehicle V is traveling, outside air (A1) is introduced from the front of the vehicle through the radiator and engine compartment, as shown by the arrows in Figure 3. At this time, in the vehicle V, the speed of the air currents (A2, A3) flowing under the vehicle is faster than the speed of the introduced outside air (A1), and the pressure is also lower. As a result, the heat shield device draws the introduced outside air (A1) into the flow passage 14 and exhausts it (A4, A5) to the underside of the vehicle. In other words, the heat shield device generates an air flow from above to below outside the central exhaust pipe 8, dissipating heat around the central exhaust pipe 8 to the outside.

[0024] At this time, in the heat shield device of the above embodiment, the extension 11A of the first heat shield 11 is located lower than the extension 12A of the second heat shield 12, and the distance L2 between the second heat shield 12 and the central exhaust pipe 8 is greater than the distance L1 between the first heat shield 11 and the central exhaust pipe 8. Therefore, the outside air (A1) drawn into the flow passage 14 passes between the upper and lower extensions 12, 11A, as shown by the dotted arrow A6 in Figure 3, and is discharged mainly to the underside of the vehicle body via the rear side of the central exhaust pipe 8.

[0025] In addition, when the vehicle V is stopped, the above-mentioned heat shield device causes the air heated by the central exhaust pipe 8 to rise, as shown by the arrows in Figure 4, but the extension portion 11A of the first heat shield plate 11 covering the upper side of the central exhaust pipe 8 suppresses the rising of the heated air and causes the heated air to stagnate between the upper and lower extension portions 12A, 11A, reducing the amount of heated air that flows out toward the tunnel T.

[0026] In this way, when the vehicle V is moving, the heat shield device cools (releases heat from) the central exhaust pipe 8 by circulating air introduced from the front of the vehicle through the flow passage 14 to the underside of the vehicle, and when the vehicle V is stopped, it prevents heat from the central exhaust pipe 8 from leaking out toward the vehicle body B.

[0027] As a result, the heat shield device can protect each unit from heat damage by the central exhaust pipe 8, without being affected by the individual vibrations of each unit such as the first unit 1, the second unit 2, and the vehicle body B that are arranged around the exhaust pipe 8. Moreover, in the heat shield device, the upper region of the circulation path 14 has a labyrinth structure formed by the extensions 11A, 12A of the first heat shield plate 11 and the second heat shield plate 12, so that it is possible to particularly suppress the rise of heat in the circulation path 14 and protect the high-voltage harness 5 and the vehicle body B that are arranged above the circulation path 14 from heat damage by the central exhaust pipe 8.

[0028] Furthermore, the above-mentioned heat shield device can obtain the labyrinth structure and its effects even if the arrangement of the extension portions 11A, 12A is reversed from that of the illustrated example, but by arranging the extension portion 11A of the first heat shield plate 11 lower than the extension portion 12A of the second heat shield plate 12, air can be more smoothly sucked into the circulation passage 14, as shown by the dotted arrow A6 in Figure 3.

[0029] Furthermore, in the above-mentioned heat shield device, the extension portion 11A of the first heat shield plate 11 has an extension length that covers the upper surface of the central exhaust pipe 8, so that it can suppress the rise of heated air, particularly when the vehicle V is stopped, and can contribute to further improving the protection function from heat damage.

[0030] Furthermore, the above-mentioned heat shielding device can suppress heat stagnation in the arrangement space while ensuring space for arranging high-voltage harnesses 5 and the like by using the tunnel section T between the first heat shielding plate 11 and the second heat shielding plate 12 and the floor panel P.

[0031] Furthermore, in the heat shield device, the first heat shield 11 and the second heat shield 12 extend in the left-right direction of the vehicle, and the distance L2 between the second heat shield 12 and the central exhaust pipe 8 is greater than the distance L1 between the first heat shield 11 and the central exhaust pipe 8. This allows the air flow in the circulation passage 14 to be concentrated to the rear side of the central exhaust pipe 8, making it possible to more smoothly suck air into the circulation passage 14, as shown by the dotted arrow A6 in Figure 3.

[0032] Furthermore, in the above-mentioned heat shield device, the second heat shield 12 is positioned relatively lower than the first heat shield 11, so that the outside air introduced from the front of the vehicle is accelerated in the flow passage 14, making it easier to release accumulated heat.

[0033] Furthermore, in the heat shield device, the extension 11A of the first heat shield plate 11 has a downward flange 11B that forms an obtuse angle with the main body, so that while the vehicle V is running, the so-called Coanda effect allows the sucked-in air to flow smoothly downward to the underside of the flange 11B. Also, while the vehicle V is stopped, the heat shield device allows the heated air to remain on the underside of the flange 11B, as shown by the arrow in Figure 4, and can prevent it from rising any further.

[0034] Furthermore, in the above-mentioned heat shield device, the extension portion 12A of the second heat shield plate 12 has a downward flange portion 12B that forms an angle with the main body portion that is smaller than the above-mentioned obtuse angle, more preferably a right angle or acute angle, so that, particularly when the vehicle V is stopped, the heated air can be caused to stagnate in a vortex on the underside of the flange portion 12B, as shown by the arrow in Figure 4, thereby reducing the amount of heated air that flows out toward the upper side of the flow passage 14.

[0035] Furthermore, the heat shield device has a structure in which the ground clearance H2 of the second unit 2 is lower than the ground clearance H1 of the first unit 1, and the central exhaust pipe 8 has, at its lower part, an inclined surface 8A that slopes downward from the first unit 1 side to the second unit 2 side, so that the entire underside from the first unit 1 through the central exhaust pipe 8 to the second unit 2 is continuous, as shown by dotted line S in Figure 3. As a result, the heat shield device has a venturi shape in which the flow path from the front to the rear on the underside of the vehicle narrows downstream, and the so-called nozzle effect accelerates the air flow under the vehicle, improving the outside air suction and introduction function of the flow passage 14.

[0036] A specific example of a vehicle is a hybrid vehicle in which the first unit is a drive source equipped with a longitudinally mounted V-type engine and the second unit is a battery pack housing multiple battery modules. In such a hybrid vehicle, when a muffler is arranged from the front to the rear of the vehicle, a central exhaust pipe must be used to join the exhaust from the V-type engine (first unit) and the second unit, resulting in a larger muffler and a larger heat output. Furthermore, because the V-type engine is longitudinally mounted, the front-to-rear space is reduced. The heat shield device of the present invention can also be used in such a hybrid vehicle to shield the engine (first unit) and the second unit from heat while suppressing heat accumulation in the floor panel.

[0037] The configuration of the heat shield device according to the present invention is not limited to the above-described embodiment, and can be modified as appropriate within the scope of the present invention.

[0038] REFERENCE SIGNS LIST 1 First unit 2 Second unit 8 Central exhaust pipe (exhaust pipe arranged between the first unit and the second unit) 8A Inclined surface 11 First heat shield plate 11A Extension portion 11B Flange portion 12 Second heat shield plate 12A Extension portion 12B Flange portion 14 Flow passage F Floor panel T Tunnel portion V Vehicle

Claims

1. The vehicle comprises a first unit that is pivotably mounted on the vehicle body, a second unit that is positioned adjacent to the first unit and fixed to the vehicle body, and an exhaust pipe positioned between the first unit and the second unit. A first heat shield fixed to the first unit and positioned between the first unit and the exhaust pipe, The system comprises a second heat shield fixed to the second unit and positioned between the second unit and the exhaust pipe, A heat shielding device characterized in that the first heat shield and the second heat shield have extensions that protrude at different heights above the exhaust pipe and whose tip portions overlap when viewed from above the vehicle.

2. The first unit and the second unit are arranged adjacent to each other in the longitudinal direction of the vehicle. The heat shielding device according to claim 1, characterized in that the exhaust pipe is arranged along the left-right direction of the vehicle between the first unit and the second unit.

3. The heat shielding device according to claim 1, characterized in that there is a flow passage between the first heat shield and the second heat shield that is opened to the underside of the vehicle from above, passing beside the exhaust pipe.

4. The heat shielding device according to claim 2, characterized in that there is a flow passage between the first heat shield and the second heat shield that is opened to the underside of the vehicle from above, passing beside the exhaust pipe.

5. The first heat shield is positioned on the front side of the vehicle body, and the second heat shield is positioned on the rear side of the vehicle body. The heat shielding device according to claim 3 or 4, characterized in that the extension portion of the first heat shield is positioned lower than the extension portion of the second heat shield.

6. The first heat shield is positioned on the front side of the vehicle body, and the second heat shield is positioned on the rear side of the vehicle body. The heat shielding device according to claim 3 or 4, characterized in that the extension portion of the first heat shield has an extension length that covers the upper surface of the exhaust pipe.

7. The first heat shield is positioned on the front side of the vehicle body, and the second heat shield is positioned on the rear side of the vehicle body. The heat shielding device according to claim 3 or 4, characterized in that a tunnel portion extending in the longitudinal direction of the vehicle body is provided between the first heat shield and the second heat shield and the floor panel.

8. The first heat shield is positioned on the front side of the vehicle body, and the second heat shield is positioned on the rear side of the vehicle body. The extensions of the first heat shield and the second heat shield each have a downward-facing flange portion at their tip. The flange portion of the extension of the first heat shield is obtuse with respect to the main body portion of the extension. The heat shielding device according to claim 3 or 4, characterized in that the flange portion of the extension portion of the second heat shield is at an angle smaller than the obtuse angle with respect to the main body portion of the extension portion.

9. The first unit is positioned on the front side of the vehicle body, and the second unit is positioned on the rear side of the vehicle body. The structure has such that the ground clearance of the second unit is lower than the ground clearance of the first unit, The heat shielding device according to claim 3 or 4, characterized in that the exhaust pipe has an inclined surface at its lower end that slopes downward from the first unit side to the second unit side.

10. The heat shielding device according to claim 3 or 4, characterized in that the first unit is a first unit including at least an engine, the second unit is a battery, and the exhaust pipe is an exhaust pipe for discharging exhaust gas from the first unit.