Heat protector structure

Abstract

A heat protector structure for covering an exhaust emission control device, comprising a first heat protector covering a first region of a surface of the exhaust emission control device, and a second heat protector covering a second region of the surface different from the first region, the second heat protector having a harness fixing part for fixing a harness to be connected to a sensor fixed to the exhaust emission control device.

Description

Heat protector structure

[0001] The present disclosure relates to a heat protector structure for an exhaust gas purification device.

[0002] Conventionally, a heat protector is attached to an engine exhaust pipe to suppress a rise in temperature around the exhaust pipe (see, for example, Patent Document 1). Patent Document 1 discloses a heat protector that can be simply fixed to the exhaust pipe.

[0003] Japanese Patent Application Laid-Open No. 2018-144719

[0004] Such exhaust pipes are fitted with exhaust purification devices that purify harmful substances contained in the exhaust. In recent years, such exhaust purification devices have included multiple sensors. The sensors are connected to harnesses that transmit the values ​​detected by the sensors to an ECU (Electronic Control Unit). It is also necessary to reduce the heat received by the harnesses extending from these sensors from the exhaust purification device.

[0005] An object of the present disclosure is to provide a heat protector structure that can suppress heat reception by a harness.

[0006] The heat protector structure of the present disclosure is a heat protector structure that covers an exhaust purification device, and includes a first heat protector that covers a first region of the surface of the exhaust purification device, and a second heat protector that covers a second region of the surface that is different from the first region, and the second heat protector has a harness fixing portion that fixes a harness connected to a sensor fixed to the exhaust purification device.

[0007] According to this heat protector structure, the second region of the surface of the exhaust gas purification device that cannot be covered by the first heat protector can be covered by the second heat protector. By fixing the harness extending from the sensor to the second heat protector, it is possible to prevent the harness from receiving heat.

[0008] 3A and 3B are cross-sectional views of a heat protector structure according to an embodiment of the present disclosure, ...

[0009] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings. The heat protector structure 1 of this embodiment is mounted on a vehicle. Therefore, in the drawings, the front side of the vehicle is designated as F, the rear side as B, the right side as R, the left side as L, the upper side as U, and the lower side as D, with the vehicle as the reference.

[0010] 1 and 2 , the heat protector structure 1 covers the surface of an exhaust purification device 2 that purifies exhaust gas emitted from an engine E. The heat protector structure 1 includes a main heat protector (an example of a first heat protector) 4, an intermediate sensor heat protector (an example of a second heat protector) 6, and an outlet sensor heat protector (an example of a second heat protector) 16.

[0011] The exhaust purification device 2 is a device that purifies exhaust gas emitted from the engine E. In this embodiment, the exhaust purification device 2 is a diesel particulate filter that purifies exhaust gas from a diesel engine. The exhaust purification device 2 in this embodiment is disposed on the right side of the engine, tilted up and down.

[0012] A plurality of sensors 2a are fixed to the exhaust purification device 2. In this embodiment, the sensors 2a are temperature sensors that detect the temperature of exhaust gas passing through the exhaust purification device 2. A total of three sensors 2a are arranged, one each at the inlet portion, middle portion, and outlet portion of the exhaust purification device 2. The sensors 2a arranged at the middle portion and the outlet portion are visible in Figures 1 and 2.

[0013] The main heat protector 4 covers a first region X1 on the surface of the exhaust purification device 2, and has the function of suppressing the transfer of heat from the exhaust purification device 2 to the surrounding area. The main heat protector 4 is formed along the surface of the cylindrical exhaust purification device 2. The main heat protector 4 mainly covers the surface of the exhaust purification device 2 opposite the engine E, and notches are provided in areas where it is difficult to attach the main heat protector 4, such as the surface 2b facing the engine E and around the sensors. Therefore, the first region X1 is the area of ​​the surface of the exhaust purification device 2 that can be covered by the main heat protector 4. The main heat protector 4 is formed from a sheet metal member.

[0014] The intermediate sensor heat protector 6 covers a second region X2, which is different from the first region X1, on the surface of the exhaust purification device 2. The second region X2 is an area of ​​the surface of the exhaust purification device 2 that cannot be completely covered by the main heat protector 4. In this embodiment, the intermediate sensor heat protector 6 covers the periphery of the sensor 2a, which is fixed to the surface 2b facing the engine E, in the second region X2. The sensor 2a is a sensor provided in the intermediate portion of the exhaust purification device 2 (hereinafter referred to as the intermediate sensor). The intermediate sensor heat protector 6 has a harness fixing portion 8 that fixes the harness 10 connected to the intermediate sensor. The intermediate sensor heat protector 6 functions as both a harness bracket and a heat protector that suppresses heat transfer from the exhaust purification device 2 to the harness. In this way, rationalization can be achieved by giving the intermediate sensor heat protector 6 two functions.

[0015] 3 and 4 , the intermediate sensor heat protector 6 has a first plate 6a and a second plate 6b. In the intermediate sensor heat protector 6 of this embodiment, both the first plate 6a and the second plate 6b are made of metal, and the intermediate sensor heat protector 6 has a double structure in which two metal plates are stacked on top of each other. The second plate 6b is arranged to overlap the first plate 6a in a direction away from the exhaust purification device 2. Parts of the first plate 6a and the second plate 6b overlap with the main heat protector 4, and the second plate 6b has a larger area than the first plate 6a, so that the area overlapping with the main heat protector 4 is larger than that of the first plate 6a.

[0016] As shown in Fig. 4, the second plate 6b covers the second region X2 and extends to the first region X1. As a result, the second plate 6b overlaps the main heat protector 4 in the vertical direction. The first plate 6a extends in a range where the second plate 6b and the main heat protector 4 do not overlap. In this embodiment, the first plate 6a is disposed with its end portion overlapping the main heat protector 4. However, the first plate 6a does not necessarily have to be disposed overlapping the main heat protector 4.

[0017] The intermediate sensor heat protector 6 has a heat protector fixing portion 12. In this embodiment, the heat protector fixing portion 12 includes a through-hole 12a penetrating the first plate 6a and the second plate 6b and a flat surface 12b along a base 2c (described later). As shown in FIG. 4 , the exhaust gas purification device 2 has a base 2c to which the intermediate sensor heat protector 6 is fixed, and a weld nut 2d is provided on the base 2c. The heat protector fixing portion 12 fixes the first plate 6a and the second plate 6b of the intermediate sensor heat protector 6 together by inserting a bolt 12c into the through-hole 12a and fixing it to the weld nut 2d. In this embodiment, the first plate 6a and the second plate 6b are further fixed to each other near the heat protector fixing portion 12 by spot welding or the like.

[0018] The intermediate sensor heat protector 6 has such a structure, which provides a gap between the exhaust purification device 2 and the second plate 6b, making it difficult for the temperature of the second plate 6b to rise. Furthermore, by spot welding the first plate 6a and the second plate 6b around the heat protector fixing portion 12, heat transfer between the first plate 6a and the second plate 6b occurs only around the heat protector fixing portion 12, thereby suppressing heat transfer from the first plate 6a to the second plate 6b. In this embodiment, the second plate 6b is formed larger than the first plate 6a and is attached to the exhaust purification device 2 so that the second plate 6b does not come into direct contact with the exhaust purification device 2. This suppresses heat transfer from the exhaust purification device 2 to the second plate 6b, and allows the second plate 6b to be cooled by air flowing between the exhaust purification device 2 and the second plate 6b.

[0019] 3, in this embodiment, the intermediate sensor heat protector 6 has heat protector fixing portions 12 in two locations: near the front end (top end) and in the vertical center of the intermediate sensor heat protector 6. However, it is sufficient to have at least one heat protector fixing portion 12.

[0020] The intermediate sensor heat protector 6 has a harness fixing portion 8. As described above, the harness fixing portion 8 has the function of fixing the harness 10. In this embodiment, the tip of the harness fixing portion 8, which is formed from sheet metal, is folded back in a semicircular shape, and the harness 10 fits into the folded back portion. The harness fixing portion 8 is fixed to the second plate 6b. More specifically, as shown in FIG. 4 , the harness fixing portion 8 is spot welded to the bracket base 8a. In this embodiment, the bracket base 8a is formed by the second plate 6b protruding rearward in a truncated pyramid shape.

[0021] The bracket base 8a is formed between the two heat protector fixing portions 12 in the vertical direction. As a result, the harness fixing portion 8 is positioned at a distance from the heat protector fixing portion 12. By positioning the harness fixing portion 8 at a distance from the heat protector fixing portion 12 in this manner, heat from the exhaust purification device 2 is prevented from being directly transferred to the harness fixing portion 8 via the heat protector fixing portion 12.

[0022] As shown in Figure 3, the harness 10 passes through the area where the main heat protector 4 and the intermediate sensor heat protector 6 overlap. The three harnesses 10 shown in Figure 3 represent the maximum and minimum values ​​of the allowable range of variation in the position of the harness 10 due to the mounting angle of the sensor 2a. The orientation of the sensor 2a changes depending on the magnitude of the tightening torque applied when mounting the sensor 2a, and the position of the harness changes. The harness 10 shown by the leftmost imaginary line represents the route in which the harness 10 passes through the leftmost part of the allowable range (small tightening torque of the sensor 2a), and the harness 10 shown by the rightmost imaginary line represents the route in which the harness 10 passes through the leftmost part of the allowable range (large tightening torque of the sensor 2a).

[0023] Even if there is variation, at least a portion of the bent portion 10a of the harness 10 passes through the area where the main heat protector 4 and the intermediate sensor heat protector 6 overlap. A portion of the harness 10 passes through the area where the first plate 6a and the second plate 6b of the intermediate sensor heat protector 6 overlap. In this way, by having the harness 10 pass through the area where the main heat protector 4 and the second plate 6b overlap, or the area where the first plate 6a and the second plate 6b overlap, it is possible to prevent the harness 10 from receiving heat from the exhaust purification device 2. In this embodiment, the harness fixing portion 8 is provided in the area where the intermediate sensor heat protector 6 overlaps with the main heat protector 4, and therefore the harness 10 around the harness fixing portion 8 also passes through the area where the main heat protector 4 and the intermediate sensor heat protector 6 overlap.

[0024] Furthermore, the intermediate sensor heat protector 6 has a rib 14 that indicates the direction in which the harness 10 (sensor 2a) should be oriented when the worker installs the harness 10. The rib 14 also functions as a reinforcing member for the intermediate sensor heat protector 6. In this embodiment, the intermediate sensor heat protector 6 has a first rib 14a that indicates the route in which the harness 10 passes along the leftmost side of the allowable range, and a second rib 14b that indicates the route in which the harness 10 passes along the rightmost side of the allowable range. By passing the harness 10 between the first rib 14a and the second rib 14b, the worker can more reliably pass the harness 10 through the area where the main heat protector 4 and the intermediate sensor heat protector 6 overlap.

[0025] As shown in FIG. 2 , the outlet sensor heat protector 16 covers a second region X2 different from the first region X1 on the surface of the exhaust purification device 2. In this embodiment, the outlet sensor heat protector 16 covers the periphery of a sensor 2a (hereinafter referred to as the outlet sensor) fixed to the outlet portion of the second region X2. As shown in FIG. 5 , the outlet sensor heat protector 16 has a harness fixing portion 20 that fixes a harness 18 connected to the outlet sensor. The outlet sensor heat protector 16 functions as both a harness bracket and a heat protector that suppresses the transfer of heat from the exhaust purification device 2 to the harness. In this way, rationalization can be achieved by providing the outlet sensor heat protector 16 with two functions.

[0026] The outlet sensor heat protector 16 has a first plate 16a and a second plate 16b. In this embodiment, the outlet sensor heat protector 16 has a double structure in which the first plate 16a and the second plate 16b are both made of metal, and the two metal plates are stacked on top of each other. The second plate 16b is positioned so as to overlap the first plate 16a in a direction away from the exhaust purification device 2. The first plate 16a differs from the intermediate sensor heat protector 6 in that the area of ​​the first plate 16a is larger than that of the second plate 16b.

[0027] The outlet sensor heat protector 16 has a heat protector fixing portion 22. In this embodiment, one heat protector fixing portion 22 is provided at each of the front and rear ends of the second plate 16b. The method for fixing the outlet sensor heat protector 16 is similar to that for the intermediate sensor heat protector 6, and therefore a description thereof will be omitted.

[0028] The outlet sensor heat protector 16 has a harness fixing portion 20. The harness fixing portion 20 has the function of fixing the harness 18. The harness fixing portion 20 is disposed at a distance from the heat protector fixing portion 22. By disposing the harness fixing portion 20 at a distance from the heat protector fixing portion 22 in this manner, heat from the exhaust purification device 2 is prevented from being directly transferred to the harness fixing portion 20 via the heat protector fixing portion 22. In addition, the harness fixing portion 20 is attached to the second plate 16b at a location away from the first plate 16a. The shape and fixing method of the harness fixing portion 20 are similar to those of the intermediate sensor heat protector 6, and therefore will not be described here.

[0029] The exit sensor heat protector 16 has a rib 24 that indicates the direction in which the harness 10 should be oriented when the worker installs the harness 18 (sensor 2a). The rib 24 also functions as a reinforcing member for the exit sensor heat protector 16. In this embodiment, the exit sensor heat protector 16 has the rib 24 at a position that indicates the route that the harness 10 should take when the harness 18 is at an intermediate length. By passing the harness 18 over the rib 24, the worker can ensure that the harness 18 takes a more accurate route. Note that the exit sensor heat protector 16 may also be provided with a first rib that indicates the route that the harness 10 takes along the leftmost side of the allowable range and a second rib that indicates the route that the harness 10 takes along the rightmost side of the allowable range.

[0030] As described above, according to the present disclosure, it is possible to provide a heat protector structure 1 that can suppress heat reception by the harnesses 10, 18.

[0031] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the invention. In particular, the multiple modifications described in this specification can be combined as needed.

[0032] (a) In the above embodiment, the exhaust purification device 2 is described as a diesel particulate filter, but the present disclosure is not limited to this. The exhaust purification device 2 may be another exhaust purification device, such as a gasoline particulate filter that purifies the exhaust gas of a gasoline engine.

[0033] (b) In the above embodiment, the exhaust purification device 2 is disposed on the right side of the engine E at an inclination up and down, but the present disclosure is not limited to this. The exhaust purification device 2 may be disposed, for example, in front of, behind, or on the left side of the engine E. Furthermore, the exhaust purification device 2 may be disposed in the up-down direction, the front-rear direction, or the left-right direction. In this case, the positions and shapes of the main heat protector 4, the intermediate sensor heat protector 6, and the outlet sensor heat protector 16 may be changed as appropriate to suit the exhaust purification device 2.

[0034] 1: Heat protector structure, 2: Exhaust gas purification device, 2a: Sensor, 6: Intermediate sensor heat protector, 6a: First plate, 6b: Second plate, 8, 20: Harness fixing portion, 10, 18: Harness, 12, 22: Heat protector fixing portion, 14, 24: Rib, 14a: First rib, 14b: Second rib, 16: Exit sensor heat protector, 16a: First plate, 16b: Second plate, E: Engine, X1: First region, X2: Second region

Claims

1. A heat protector structure covering an exhaust gas purification device, comprising: a first heat protector covering a first region on the surface of the exhaust gas purification device; and a second heat protector covering a second region which is a surface different from the first region, wherein the second heat protector has a harness fixing portion for fixing a harness connected to a sensor fixed to the exhaust gas purification device.

2. The heat protector structure according to claim 1, wherein the second heat protector includes a first plate, a second plate disposed overlapping the first plate in a direction away from the exhaust gas purification device, and a heat protector fixing portion for fixing the second heat protector, and the first plate is fixed to the exhaust gas purification device.

3. The heat protector structure according to claim 2, wherein the harness fixing portion is disposed on the second plate and is spaced apart from the heat protector fixing portion.

4. The heat protector structure according to claim 1, wherein the harness passes through a range where the first heat protector and the second heat protector overlap.

5. The heat protector structure according to claim 1, wherein the second heat protector has ribs indicating the direction of the harness.

6. The heat protector structure according to any one of claims 1 to 5, wherein the second heat protector includes a first plate and a second plate disposed overlapping the first plate in a direction away from the exhaust gas purification device, the second plate extends to the first region and overlaps the first heat protector, and the first plate extends in a range where the second plate and the first heat protector do not overlap.

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