JP5271732B2 - Exhaust purification device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent thermal damage to peripheral parts while arranging an exhaust emission control device close to a diesel engine, and prevent the deterioration of an emission control efficiency of an exhaust gas while making reproduction of a particulate filter advantageous by controlling heat radiation from an outer peripheral part of the particulate filter. <P>SOLUTION: An exhaust emission control device 14 which is provided in a midway part of an exhaust pipe (an inlet side exhaust pipe 31 or the like) in an engine 10 and arranged in the vicinity of the engine 10, consists of an exhaust emission control device body 40 which is connected to the inlet side exhaust pipe 31 and which incorporates a particulate filter 53, a cover 42 which is provided around the exhaust emission control device body 40 and covers the exhaust emission control device body 40 from the outside, and an inside heat insulator 41 which is provided between the exhaust emission control device body 40 and cover 42 and arranged so as to produce air layers 78, 79 in gaps with the exhaust emission control device body 40 and with the cover 42. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a technology of an exhaust emission control device for a diesel engine.

  In recent years, in consideration of environmental problems, it is desired to mount an exhaust purification device (exhaust aftertreatment device, black smoke purification device) on various vehicles such as buses and tractors. The exhaust purification device is a device in which an exhaust inlet, an oxidation catalyst, a diesel particulate filter (DPF; hereinafter referred to as a particulate filter), and an exhaust outlet are arranged in series. The particulate filter provided in such an exhaust emission control device is clogged and deteriorates its function when used continuously. Therefore, the particulate matter (PM) accumulated on the filter is burnt (oxidized) and removed. Have to play. In order to perform this regeneration, it is necessary to maintain the temperature of the oxidation catalyst and the particulate filter at about 300 ° C., and for maintaining the increase, the thermal energy of the exhaust gas is used, or post injection (combustion process). The heat obtained by combusting the fuel after the additional injection) in the exhaust purification system is used. For this reason, the particulate filter is preferably disposed at a position where the temperature of the exhaust gas is high, that is, in the vicinity of the engine.

  Therefore, for example, a technique for disposing a particulate filter behind an engine in an engine room is known by the technique disclosed in Patent Document 1. In the technique disclosed in Patent Document 1, the particulate filter is not easily affected by the traveling wind, and the particulate filter can be maintained at a high temperature. However, if the particulate filter is disposed in a place where the traveling wind does not hit in the engine room, the particulate filter becomes too hot and the peripheral parts in the engine room are adversely affected by heat (so-called thermal damage). There was an evil.

  Further, for example, with the technique disclosed in Patent Document 2, a technique is known in which the particulate filter is disposed in the vicinity of the engine and in front of the radiator that sends the traveling wind. With the technique disclosed in Patent Document 2, it is possible to operate the particulate filter while cooling it with traveling wind, and it is possible to prevent the particulate filter from becoming too hot. However, the outer peripheral portion of the particulate filter is more easily cooled by the traveling wind than the central portion, and heat is easily radiated from the outer peripheral portion of the particulate filter. Therefore, the activity of the oxidation catalyst tends to be lower at the outer peripheral portion of the particulate filter than at the central portion, and it is difficult to keep the temperature of the oxidation catalyst and the particulate filter uniformly elevated to about 300 ° C. It was difficult to reproduce the whole uniformly. Therefore, it is difficult to obtain a uniform purification effect in the entire filter of the particulate filter.

JP 2006-70878 A JP 2008-184107 A

  The present invention has been made in view of the above circumstances, and while disposing an exhaust purification device in the vicinity of a diesel engine, it prevents thermal damage to peripheral components, and from the outer periphery of the particulate filter. It is an object of the present invention to suppress heat dissipation, to make the regeneration of the particulate filter advantageous, and to prevent the exhaust gas purification effect from decreasing.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

In Claim 1, the exhaust pipe of an engine (10) is comprised by the inlet side exhaust pipe (31) and the outlet side exhaust pipe (56), and this inlet side exhaust pipe (31), outlet side exhaust pipe (56), An exhaust purification device (14) is interposed in the vicinity of the engine (10) in the middle of the exhaust purification device main body (40) and the inner heat insulating material (41). And the cover (42) and the outer heat insulating material (43). The exhaust purification device main body (40) includes a casing (50) provided with an oxidation catalyst (52) and a particulate filter (53) inside. ), The inlet side exhaust pipe (31) and the outlet side exhaust pipe (56) are connected, and the inner heat insulating material (41) is made of a heat insulating material such as glass wool or ceramic, The purifier body (40) is covered and the cover (4 ) Is composed of a member made of a heat-resistant material such as a metal, and is composed of a right cover (64) and a left cover (65). The outer heat insulating material (43) is made of a heat insulating material such as glass wool or ceramic, covers the periphery of the cover (42), and the outer peripheral surface of the exhaust purification device main body (40). And an inner peripheral surface of the inner heat insulating material (41) to form an air layer (78), and the outer peripheral surface of the inner heat insulating material (41) and the inner surface of the cover (42) An air layer (79) is formed by providing a gap with the peripheral surface .

  As effects of the present invention, the following effects can be obtained.

In Claim 1, the exhaust pipe of an engine (10) is comprised by the inlet side exhaust pipe (31) and the outlet side exhaust pipe (56), and this inlet side exhaust pipe (31), outlet side exhaust pipe (56), An exhaust purification device (14) is interposed in the vicinity of the engine (10) in the middle of the exhaust purification device main body (40) and the inner heat insulating material (41). And the cover (42) and the outer heat insulating material (43). The exhaust purification device main body (40) includes a casing (50) provided with an oxidation catalyst (52) and a particulate filter (53) inside. ), The inlet side exhaust pipe (31) and the outlet side exhaust pipe (56) are connected, and the inner heat insulating material (41) is made of a heat insulating material such as glass wool or ceramic, The purifier body (40) is covered and the cover (4 ) Is composed of a member made of a heat-resistant material such as a metal, and is composed of a right cover (64) and a left cover (65). The outer heat insulating material (43) is made of a heat insulating material such as glass wool or ceramic, covers the periphery of the cover (42), and the outer peripheral surface of the exhaust purification device main body (40). And an inner peripheral surface of the inner heat insulating material (41) to form an air layer (78), and the outer peripheral surface of the inner heat insulating material (41) and the inner surface of the cover (42) Since the air layer (79) is formed by providing a gap with the peripheral surface, the periphery of the exhaust purification device main body is covered with the inner heat insulating material. It is possible to prevent heat damage.

  Further, it is possible to suppress the heat release from the outer peripheral portion of the particulate filter to make the regeneration of the particulate filter advantageous, and to prevent the exhaust gas purification effect from being lowered.

In addition , since the periphery of the exhaust purification device main body is doubly covered by the inner heat insulating material and the outer heat insulating material, it is possible to effectively prevent thermal damage to peripheral components while arranging the exhaust purification device in the vicinity of the engine. It becomes possible.

Further , it is possible to suppress the heat release from the outer peripheral portion of the particulate filter to make the regeneration of the particulate filter advantageous, and to prevent the exhaust gas purification effect from being lowered.

In addition , since the particulate filter can be removed while the exhaust purification device is connected to the engine via the exhaust pipe, maintenance such as cleaning of the particulate filter can be easily performed.

1 is a side view showing an overall configuration of a power shovel including an exhaust purification device according to a first embodiment of the present invention. It is a plane schematic diagram showing an internal configuration of a hood of a power shovel. It is a back schematic diagram which shows the structure inside the bonnet of a power shovel. It is a perspective view which shows the structure of an exhaust gas purification apparatus main body. It is a left side section schematic diagram showing composition of an exhaust emission control device main part. It is a perspective view which shows the state which attached the inner side heat insulating material to the exhaust gas purification apparatus main body. It is a perspective view which shows the state which attached the inner side heat insulating material and the left side cover to the exhaust gas purification device main body. It is a perspective view which shows the state which attached the inner side heat insulating material and the cover (the left side cover and the right side cover) to the exhaust gas purification apparatus main body. It is a perspective view which shows a state when an inner side heat insulating material, a cover, and an outer side heat insulating material are attached to the exhaust gas purification apparatus main body, and is a perspective view which shows the structure of the exhaust gas purification apparatus which concerns on 1st embodiment. It is a back section schematic diagram showing composition of an exhaust-air-purification device. It is a left side section schematic diagram showing composition of an exhaust emission control device. It is a perspective view which shows the structure of the exhaust gas purification apparatus which concerns on 2nd embodiment, and is the figure which abbreviate | omitted and showed the outer side heat insulating material.

  Next, embodiments of the invention will be described with reference to the accompanying drawings.

  First, an overall configuration of a power shovel 1 including an exhaust purification device 14 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. In addition, the exhaust emission control device according to the present invention is not limited to that provided in the power shovel 1, but may be provided in other agricultural work vehicles, civil engineering work vehicles, or the like.

  In the following, for the sake of convenience, the direction in which gravity acts is “up and down direction”, the direction perpendicular to the up and down direction, the direction of arrow A in FIG. It is defined as “direction”, and explanation will be made using these directions.

  As shown in FIG. 1, the excavator 1 mainly includes a crawler type traveling device 2, a main body frame 3, an operation unit 4, a bonnet 5, a work machine 6, a blade 7, and the like.

  The crawler type traveling device 2 is a traveling device for traveling the power shovel 1. The main body frame 3 is mounted on the crawler type traveling device 2 so as to be able to turn left and right.

  The operation unit 4 is disposed at the front of the main body frame 3 and includes various operation levers, foot pedals, and the like. As shown in FIG. 2, the bonnet 5 is provided in a substantially arc shape in plan view at the rear of the main body frame 3, and houses the engine 10, the hydraulic pump 11, the hydraulic oil tank 12, the radiator 13, the exhaust purification device 14, and the like. Covered. As shown in FIG. 1, a seat 15 is disposed in the vicinity of the front upper part of the bonnet 5.

  As shown in FIG. 1, the work implement 6 is provided at the front end of the main body frame 3 and includes a boom 16, an arm 17, a bucket 18, a boom cylinder 19, a bucket cylinder 20, an arm cylinder 22, and the like. A boom bracket 21 is pivotally supported at the front end of the main body frame 3 so as to be turnable in the left-right direction. One end of the boom 16 is pivotally supported by the front end of the boom bracket 21. One end of the arm 17 is pivotally supported by the other end of the boom 16. One end of the bucket 18 is pivotally supported by the other end of the arm 17. In this way, the work implement 6 can turn the boom 16 up and down by the boom cylinder 19, can turn the arm 17 up and down by the arm cylinder 22, and can turn the bucket 18 up and down by the bucket cylinder 20.

  The blade 7 protrudes from the rear end portion of the crawler type traveling device 2 and is supported by a lift cylinder so as to be vertically rotatable.

  Next, the internal configuration of the bonnet 5 will be described with reference to FIGS. As described above, the bonnet 5 houses and covers the engine 10, the hydraulic pump 11, the hydraulic oil tank 12, the radiator 13, the exhaust purification device 14, and the like.

  As shown in FIGS. 2 and 3, the engine 10 is provided in the center of the rear part of the main body frame 3 via an engine support member 30 (see FIG. 3). A flywheel is attached to the left side of the engine 10. The flywheel is housed in a flywheel case 35 (see FIG. 3). The engine 10 includes an inlet side exhaust pipe 31 (see FIG. 2) connected to an upper exhaust manifold (not shown) for exhausting exhaust gas (combustion gas). A cooling fan 9 is attached to the right side of the engine 10.

  As shown in FIG. 3, the hydraulic pump 11 is provided on the flywheel case 35 side (the left side of the engine 10) of the engine 10. The hydraulic pump 11 is driven by the crankshaft (output shaft) of the engine 10.

  The hydraulic oil tank 12 is a tank that stores hydraulic oil for hydraulic equipment, and is provided on the rear left side of the main body frame 3 (left side of the engine 10). A hydraulic hose 24 is connected to the lower side surface of the hydraulic oil tank 12. The hydraulic oil in the hydraulic oil tank 12 is supplied to the hydraulic pump 11 through the hydraulic hose 24.

  The radiator 13 is a device for dissipating (cooling) excessive heat generated in the engine 10. As shown in FIG. 2, the radiator 13 is connected to the right side of the cooling fan 9 (on the right side of the engine 10) and is arranged at a predetermined interval from the side wall of the bonnet 5. A duct 33 is provided between the radiator 13 and the side wall of the bonnet 5, and cooling air from the cooling fan 9 can be discharged to the outside through the duct 33. The duct 33 is provided with a louver 34, and the direction of the cooling air from the cooling fan 9 can be changed.

  The exhaust purification device 14 is a device that removes particulate matter contained in the exhaust gas of the engine 10. As shown in FIGS. 2 and 3, the exhaust purification device 14 is a member having a substantially hexagonal cylindrical shape (substantially hexagonal column shape) when viewed from the back. The exhaust purification device 14 is disposed in the vicinity of the engine 10. The exhaust purification device 14 is provided above the hydraulic pump 11 and between the engine 10 and the hydraulic oil tank 12 so that the axial direction thereof is the front-rear direction of the power shovel 1.

  The exhaust purification device 14 is provided in the middle of the exhaust pipe of the engine 10, that is, between the inlet side exhaust pipe 31 and an outlet side exhaust pipe 56 described later. As shown in FIG. 2, the inlet side exhaust pipe 31 of the engine 10 is connected to the right outer peripheral surface of the exhaust purification device 14, and the exhaust gas exhausted from the engine 10 passes through the inlet side exhaust pipe 31. It is introduced in.

  Hereinafter, the exhaust emission control device 14 will be described with reference to FIGS. 4 to 11.

  The exhaust purification device 14 is disposed at a position near the engine 10 inside the hood 5 of the power shovel 1 (see FIGS. 2 and 3). The exhaust purification device 14 is fixed to the flywheel case 35 of the engine 10 via the stay 32 in the middle part of the front and rear, and is connected to the engine 10 via the inlet side exhaust pipe 31 at the front part.

  As shown in FIGS. 4 to 11, the exhaust purification device 14 includes an exhaust purification device main body 40, an inner heat insulating material 41, a cover 42, and an outer heat insulating material 43.

  The exhaust purification device main body 40 constitutes a main structure of the exhaust purification device 14 according to the present embodiment. As shown in FIGS. 4 and 5, the exhaust purification device main body 40 includes a housing 50, an inlet pipe 51, an oxidation catalyst 52, a particulate filter 53, a heat insulating sound absorbing material 54, a main body heat insulating material 55, and an outlet side exhaust pipe 56. , And a resonance tube 57 and the like.

  The casing 50 is a member that forms an outline of the exhaust purification apparatus main body 40. As shown in FIG. 4, the housing 50 includes a first housing portion 80, a second housing portion 81, and a third housing portion 82.

  As shown in FIG. 5, the first housing part 80 is a member that forms the front part of the housing 50. The first housing part 80 is formed in a substantially cylindrical shape, and is arranged so that the axial direction thereof is the front-rear direction. The front end of the first casing 80 is closed by the front lid 90, and the rear end of the first casing 80 is opened rearward.

  A flange 91 is provided around the rear edge of the first casing 80 so as to project radially outward of the first casing 80 in the radial direction. In the flange portion 91, through holes for penetrating bolts 88, 88 to be described later are formed at predetermined intervals in the circumferential direction. In the flange portion 91, the peripheral edge portions 92, 92,... Of the through hole are formed so as to largely protrude outward in the radial direction of the first housing portion 80 than other portions of the flange portion 91.

  The second housing portion 81 is a member that forms a front-rear halfway portion of the housing 50. The second housing part 81 is formed in a substantially cylindrical shape. The second housing part 81 is arranged behind the first housing part 80 and coaxially with the first housing part 80. The front end of the second housing part 81 is opened forward and the rear end is opened backward. The second housing portion 81 is formed so that the inner diameter matches the inner diameter of the first housing portion 80 and the outer diameter matches the outer diameter of the first housing portion 80.

  Around the front edge and the rear edge of the second casing 81, flanges 93 and 93 are provided so as to protrude radially outward of the second casing 81 in the radial direction. In the flange portions 93, 93, through holes for penetrating bolts 88, 88, which will be described later, are formed at predetermined intervals in the circumferential direction. The through holes of the flange portions 93 and 93 are formed at positions where they can coincide with the through holes of the flange portion 91 described above when viewed from the front (back view). Of the flange portions 93, 93, the peripheral portions 94, 94... Of the through-holes are radially outer of the second housing portion 81 than the other portions of the flange portions 93, 93, similarly to the peripheral portion 92. Formed so as to protrude greatly.

  The third housing portion 82 is a member that forms the rear portion of the housing 50. The third housing part 82 is formed in a substantially cylindrical shape. The third housing portion 82 is disposed behind the second housing portion 81 and coaxially with the second housing portion 81. The front end of the third housing part 82 is opened forward, and the rear end of the third housing part 82 is closed by a rear lid 95. The third housing portion 82 is formed so that the inner diameter matches the inner diameter of the second housing portion 81 and the outer diameter matches the outer diameter of the second housing portion 81.

  A hole 99 is formed at a position corresponding to the position where the outlet side exhaust pipe 56 (exhaust pipe) of the rear lid 95 is provided.

  A flange portion 96 is provided around the front end edge of the third housing portion 82 so as to protrude radially outward of the second housing portion 81. In the flange portion 96, through holes for penetrating bolts 88, 88 to be described later are formed at predetermined intervals in the circumferential direction. In the flange portion 96, the peripheral edge portions 97, 97... Of the through hole are radially outer of the third housing portion 82 than the other portions of the flange portion 96, similarly to the peripheral edge portion 92 and the peripheral edge portion 94. Formed so as to protrude greatly.

  The first housing part 80, the second housing part 81, and the third housing part 82 are provided with a through hole of the flange part 91, a through hole of the flange parts 93 and 93, and a through hole of the flange part 96. Are aligned in front view (back view), and bolts 88 are inserted into the respective through holes and fastened with nuts (not shown) so as to be connected in an airtight manner. At this time, it is preferable to provide a gasket between the first casing 80 and the second casing 81 and between the second casing 81 and the third casing 82.

  By configuring in this way, the third housing part 82 can be detached from the second housing part 81. Similarly, the second housing part 81 is detachable from the first housing part 80 and the third housing part 82. Here, the first housing portion 80 is fixed to the flywheel case 35 of the engine 10 via the stay 32.

  As shown in FIG. 5, the inlet pipe 51 is formed in a substantially cylindrical shape and penetrates part of the side surface of the housing 50 from the right side of the first housing portion 80. At one end of the inlet pipe 51, an opening 39 for connection to the inlet side exhaust pipe 31 is formed (see FIG. 4). The other end of the inlet pipe 51 is opened in the first housing 80 (see FIG. 5). The inlet pipe 51 is arranged so that its axis is orthogonal to the axis of the housing 50. Thus, the inlet pipe 51 forms a passage for guiding the exhaust gas from the engine 10 into the exhaust purification device main body 40.

  The oxidation catalyst 52 is a catalyst that functions to promote the combustion of particulate matter, and is housed in the exhaust purification apparatus main body 40 as shown in FIG. The oxidation catalyst 52 is formed, for example, by forming a catalyst support layer of alumina on a substantially cylindrical monolith support by coating, and supporting catalyst components such as Pt (platinum) and Pd (palladium) on the support layer. The oxidation catalyst 52 is accommodated in the first housing part 80. The oxidation catalyst 52 is disposed on the downstream side of the opening of the inlet pipe 51.

  By providing such an oxidation catalyst 52, hydrocarbons and carbon monoxide contained in exhaust gas are changed to carbon dioxide and water, and nitrogen monoxide in nitrogen oxides (NOx) is efficiently changed to nitrogen dioxide. The particulate matter captured by the particulate filter 53 in the subsequent stage can be burned using the nitrogen dioxide generated here. Therefore, it is possible to efficiently regenerate the particulate filter 53 in a short time.

  The particulate filter 53 is a filter for collecting particulate matter, and is housed in the exhaust purification apparatus main body 40 as shown in FIG. The particulate filter 53 is a wall flow type filter formed in a substantially cylindrical shape, and includes a filter main body formed of a honeycomb-shaped porous wall having a plurality of passages by ceramics such as cordierite. The exhaust gas is circulated through the porous wall of the filter body to collect the particulate matter. The particulate filter 53 is housed in the housing 50 (in the rear portion of the first housing portion 80 and in the second housing portion 81). The particulate filter 53 is disposed on the downstream side of the oxidation catalyst 52.

  The configuration of the particulate filter 53 is not particularly limited to the above-described one, and for example, the particulate filter 53 may be configured by a three-dimensional network structure carrier using a heat resistant material such as silicon carbide. Alternatively, the oxidation catalyst and the particulate filter may be integrated, and the oxidation catalyst may be applied to the surface of the particulate filter or may be supported.

  The heat insulating sound-absorbing material 54 prevents the heat of the exhaust gas sent into the first casing 80 from being released to the outside of the first casing 80, and the sound of the first casing that generates sound when exhaust gas is discharged. This prevents leakage to the outside of 80 (outside of the exhaust purification apparatus main body 40). The heat insulating sound absorbing material 54 is fixed to the inside of the first housing portion 80 from the front portion to the middle portion of the first housing portion 80.

  The in-body heat insulating material 55 is a member that prevents heat radiation from the inside of the exhaust purification apparatus main body 40 to the outside. The main body heat insulating material 55 is fixed to the entire inner side of the rear portion of the first casing portion 80 and the inner side of the second casing portion 81.

  As shown in FIG. 4, the outlet side exhaust pipe 56 is an exhaust pipe formed by bending a substantially cylindrical member at an intermediate portion. The outlet side exhaust pipe 56 is arranged behind the particulate filter 53 and coaxially with the particulate filter 53. The outlet side exhaust pipe 56 is penetrated through the rear cover 95 of the third housing part 82 through the hole 99. The outlet side exhaust pipe 56 is fixed to the rear lid 95 via the stay 45, bolts 46, 46... And nuts.

  As shown in FIG. 5, the front end of the outlet side exhaust pipe 56 opens in the third housing portion 82 on the downstream side of the particulate filter 53. The rear end of the outlet side exhaust pipe 56 is opened outside the exhaust purification device 14 (outside the bonnet 5). Thus, the outlet side exhaust pipe 56 forms a passage that guides the exhaust gas purified by passing through the particulate filter 53 to the outside of the exhaust purification apparatus main body 40.

  As shown in FIG. 4, the outlet side exhaust pipe 56 can be detached from the rear cover 95 together with the stay 45 by attaching / detaching bolts 46, 46... And nuts. .

  The resonance tube 57 is a member that reduces noise when exhaust gas is discharged. As shown in FIG. 5, the resonance pipe 57 is a substantially cylindrical member provided in parallel with the outlet side exhaust pipe 56. Both ends of the resonance tube 57 are open. The resonance pipe 57 is provided in the third housing portion 82 in a state where the axis thereof is parallel to the axis of the outlet side exhaust pipe 56.

  By configuring in this way, the bolts 88, 88... And the nuts are removed and the third housing portion is removed while the first housing portion 80 remains connected to the engine 10 via the inlet side exhaust pipe 31. By removing the 82 and the second casing portion 81 from the first casing portion 80, the particulate filter 53 can be pulled out and removed rearward. Therefore, at the time of maintenance or the like, in the exhaust purification apparatus main body 40, it is possible to remove the particulate filter 53 from the housing 50 and clean or replace the particulate filter 53.

  Below, the structure of the inner side heat insulating material 41 is demonstrated in detail with reference to FIG.6, FIG.10 and FIG.11. The inner heat insulating material 41 is made of a heat insulating material such as glass wool or ceramic. As shown in FIG. 6, the inner heat insulating material 41 includes a front lid 58, a rear lid 59, and a side body 60, and is provided around the exhaust purification device main body 40.

  In the inner heat insulating material 41 of the present embodiment, the front lid 58, the rear lid 59, and the side body 60 are integrally formed, but the present invention is not limited to this. That is, the front lid, the rear lid, and the side surface may be provided as separate bodies, and may be held at a predetermined position by being surrounded by a cover described later.

  When the inner heat insulating material 41 is attached around the exhaust purification device main body 40, the front lid 58 covers the exhaust purification device main body 40 from the front. Further, the rear lid 59 covers the exhaust purification device main body 40 from the rear. Further, the side body 60 surrounds and covers the side surface of the exhaust purification apparatus main body 40. The side body 60 is provided so as to protrude along the outer periphery of the flange portions 91, 93, 93, and 96 (housing 50). Thus, the inner heat insulating material 41 is disposed in a cylindrical shape around the exhaust purification device main body 40.

  A gap is formed between the exhaust purification device main body 40 and the inner heat insulating material 41 (see FIGS. 10 and 11). That is, the side body 60 of the inner heat insulating material 41 is disposed so that the inner peripheral surface thereof is along the outer periphery of the flange portions 91, 93, 93, and 96, whereby the flange portions 91, 93, and 93 of the housing 50 are disposed. An air layer 78 (gap) is formed between the outer peripheral surface of the portion excluding 96 and the inner peripheral surface of the inner heat insulating material 41. Further, the side body 60 of the inner heat insulating material 41 is disposed such that the inner peripheral surface thereof is along the outer periphery of the flange portions 91, 93, 96, so that the side body 60 has the flange portions 91, 93, 96. .. Are formed at predetermined intervals in the circumferential direction of the side body 60.

  As shown in FIG. 6, a hole 61 is formed in a portion of the side body 60 corresponding to the position where the inlet pipe 51 is disposed. A hole 62 is formed in a portion of the side body 60 corresponding to the position where the stay 32 is disposed. A substantially rectangular hole 63 is formed in a portion of the rear lid 59 of the side body 60 corresponding to a position where the outlet side exhaust pipe 56 and the stay 45 are disposed.

  Thus, the inner heat insulating material 41 can cover (cover) the entire outer periphery of the exhaust purification device main body 40 other than the portion where the inlet pipe 51, the stay 32, the outlet side exhaust pipe 56, and the stay 45 are disposed. ing. By comprising in this way, the inner side heat insulating material 41 can prevent the thermal radiation from the exhaust purification apparatus main body 40 to the exterior. In other words, the inner heat insulating material 41 can suppress a decrease in temperature from the outer peripheral portions of the oxidation catalyst 52 and the particulate filter 53.

  Furthermore, the air layer 78 formed between the exhaust purification device main body 40 and the inner heat insulating material 41 also serves to prevent heat radiation from the exhaust purification device main body 40 to the outside (see FIGS. 10 and 11). That is, by interposing the air layer 78 having low thermal conductivity, heat transmission from the exhaust purification device main body 40 to the inner heat insulating material 41 is suppressed.

  Below, the structure of the cover 42 is demonstrated in detail with reference to FIG.7, FIG.8, FIG.10 and FIG. The cover 42 is a member made of a heat resistant material such as metal. The cover 42 includes a right cover 64 and a left cover 65, and is provided around the exhaust purification device main body 40 (around the inner heat insulating material 41). In order to facilitate molding, the cover 42 of the present embodiment has a structure that can be divided into left and right parts, and is configured as a substantially hexagonal cylindrical body as a whole, but the shape is particularly limited to this. It is not a thing. In other words, it can be configured integrally in a rectangular tube shape or a cylindrical shape, or can be configured in three or more parts.

  As shown in FIG. 7, flanges 84 and 84 projecting to the side are formed on the side in the longitudinal direction among the sides facing the right cover 64 (the overlapping portion) of the left cover 65. In the flange portions 84 and 84, through holes 84h, 84h, and the like are provided at predetermined intervals in the longitudinal direction of the left cover 65, for inserting bolts 89 and 89 (see FIG. 8) described later. It is formed.

  As shown in FIG. 8, flanges 83 and 83 projecting laterally are formed on the sides in the longitudinal direction of the right side cover 64 facing the left side cover 65 (the overlapping portion). The flange portions 83 and 83 are formed so as to face the flange portions 84 and 84. In the flange portions 83 and 83, through holes (not shown) are formed at positions where they can coincide with the through holes of the flange portions 84 and 84 described above.

  Thus, the right cover 64 and the left cover 65 overlap the flange portions 83 and 83 and the flange portions 84 and 84, so that the through holes of the flange portions 83 and 83 and the through holes 84h of the flange portions 84 and 84 are overlapped.・ In a state where 84h... Coincides with each other, bolts 89 are inserted into the respective through holes and fastened with nuts (not shown), so that they can be fastened and fixed to each other. Yes.

  When the right cover 64 and the left cover 65 are fixed, the left cover 65 is disposed so that the mating surface of the flange portions 84 and 84 is an inclined surface facing diagonally upward to the right, while the right cover 64 is the flange portion 83. -It is arrange | positioned so that the alignment surface of 83 may become the inclined surface which faces the left diagonal downward. Thereby, in the cover 42, the fastening and releasing operations using the bolts 89, 89... And the nuts are easy.

  When the cover 42 is attached around the exhaust purification device main body 40 and the inner heat insulating material 41 covering the exhaust purification device main body 40, the right cover 64 covers the inner heat insulating material 41 from the right side. The left cover 65 covers the inner heat insulating material 41 from the left side (see FIG. 7). A hole 66 is formed in a portion corresponding to the inlet pipe 51 of the right cover 64. Further, a hole 67 is formed in a portion corresponding to the stay 32 of the right cover 64. A triangular notch 68 is formed in a portion of the right cover 64 corresponding to the outlet side exhaust pipe 56 and the stay 45. A triangular notch 69 is formed in a portion of the left cover 65 corresponding to the outlet side exhaust pipe 56 and the stay 45.

  Thus, the cover 42 further covers the entire outer periphery of the exhaust purification device main body 40 covered with the inner heat insulating material 41 except for the portions where the inlet pipe 51, the stay 32, the outlet side exhaust pipe 56, and the stay 45 are disposed (covering). ) Is possible. By configuring in this way, the cover 42 covers the outer periphery of the inner heat insulating material 41 and holds the inner heat insulating material 41 on the outer periphery of the exhaust purification device main body 40.

  When the cover 42 is attached around the inner heat insulating material 41, a gap is generated between the inner heat insulating material 41 and the cover 42 (see FIGS. 10 and 11). That is, the cover 42 (the right cover 64) is positioned at a predetermined position by contacting the inlet pipe 51, the stay 32, etc., so that the gap between the outer peripheral surface of the inner heat insulating material 41 and the inner peripheral surface of the cover 42 is increased. An air layer 79 (gap) is formed. The air layer 79 serves to prevent heat radiation from the inner heat insulating material 41 (exhaust gas purification device body 40) to the outside. That is, the heat transfer from the inner heat insulating material 41 (exhaust gas purification device 14) to the cover 42 is suppressed by interposing the air layer 79 having low heat conductivity.

  Below, the structure of the outer side heat insulating material 43 is demonstrated in detail with reference to FIG. The outer heat insulating material 43 is made of a heat insulating material such as glass wool or ceramic. The outer heat insulating material 43 includes a front lid 70, a rear lid 71, and a side body 72, and is provided around the cover 42 (see FIG. 8).

  In the exhaust purification device 14 of the present embodiment, the front lid 70, the rear lid 71, and the side body 72 are integrally provided, but the present invention is not limited to this. In other words, the front lid, the rear lid, and the side surfaces may be provided individually and fixed to the outer peripheral surface of the cover.

  When the outer heat insulating material 43 is attached around the cover 42, the front lid 70 covers the cover 42 from the front. The rear lid 71 covers the cover 42 from the rear. Further, the side body 72 surrounds and covers the side surface of the cover 42. The side body 72 is disposed along the outer periphery of the cover 42. Therefore, projecting portions 76 and 76 projecting to the side of the side body 72 are formed at portions corresponding to the flange portions 83 and 84 of the cover 42. Moreover, the protrusion part 85 * 85 ... which protruded from the protrusion part 76 to the side is formed in the part corresponding to volt | bolt 89 * 89 ....

  A hole 73 is formed in a portion corresponding to the inlet pipe 51 of the side body 72. A hole 74 is formed in a portion corresponding to the stay 32 of the side body 72. A substantially square hole 75 is formed in a portion of the rear lid 71 corresponding to the outlet side exhaust pipe 56 and the stay 45.

  Thus, the outer heat insulating material 43 is the entire outer periphery of the exhaust purification apparatus main body 40 covered with the inner heat insulating material 41 and the cover 42 except for the portion where the inlet pipe 51, the stay 32, the outlet side exhaust pipe 56 and the stay 45 are arranged. Can be further covered (covered). Therefore, the outer heat insulating material 43 can cover the outer periphery of the cover 42 to prevent heat radiation from the cover 42 (exhaust gas purification apparatus body 40) to the outside. In other words, the outer heat insulating material 43 can suppress a temperature drop from the outer peripheral portions of the oxidation catalyst 52 and the particulate filter 53.

  With this configuration, the exhaust gas purification device 14 of the present embodiment is disposed in the vicinity of the engine 10, so that the distance from the exhaust outlet of the engine 10 to the particulate filter 53 is reduced, and high-temperature exhaust gas is removed from the particulate matter. It is possible to feed the curate filter 53. That is, by preventing the exhaust gas from being cooled before the exhaust gas is sent to the particulate filter 53, the temperature of the oxidation catalyst 52 and the particulate filter 53 can be easily maintained at about 300 ° C. The regeneration of the curate filter 53 can be advantageously performed. This contributes to preventing the particulate filter 53 from being clogged and thus preventing a reduction in the exhaust gas purification effect.

  Further, the periphery of the exhaust purification device main body 40 is covered with the inner heat insulating material 41, and further, the periphery of the inner heat insulating material 41 is covered with the outer heat insulating material 43 through the cover 42. It becomes possible to suppress heat dissipation. Therefore, a decrease in temperature from the outer peripheral portion of the particulate filter 53 can be mitigated, and a decrease in the activity of the oxidation catalyst 78 in the outer peripheral portion of the particulate filter 53 can be suppressed. Therefore, a uniform purification effect can be obtained in the entire filter of the particulate filter 53, and the exhaust gas can be purified efficiently.

Further, the periphery of the exhaust purification device main body 40 is covered with an inner heat insulating material 41, and further, the inner heat insulating material 41 is covered with an outer heat insulating material 43 through a cover 42, so that the particulate filter 53 has. Heat can be prevented from being conducted to peripheral components in the bonnet 5, and thermal damage to the peripheral components (adverse effects due to heat) can be prevented.
Further, the load on the engine 10 due to the heat radiation from the particulate filter 53 can be reduced, and the heat balance performance in the hood 5 can be ensured.

  Furthermore, in the exhaust purification device 14 of the present embodiment, in addition to the inner heat insulating material 41 and the outer heat insulating material 43, the air layer 78 and the air layer 79 also have a heat insulating action, so that more effective heat insulating performance can be obtained. It becomes possible to obtain the temperature, and the temperature management becomes easy (see FIGS. 10 and 11).

  In the exhaust purification device 14 of the present embodiment, an air layer 78 (gap) is formed between the inner heat insulating material 41 and the exhaust purification device 14, and in addition to this, the inner heat insulating material 41 and the cover 42 The air layer 79 (gap) is formed between them, but the present invention is not limited to this. For example, an air layer is formed only between the inner heat insulating material and the exhaust purification device, and the inner heat insulating material and the cover are formed. It is good also as what does not form an air layer between.

  As described above, the exhaust purification device 14 is provided in the middle of the exhaust pipe of the engine 10 (between the inlet side exhaust pipe 31 and an outlet side exhaust pipe 56 described later), and is disposed in the vicinity of the engine 10. The purifying device 14, which is connected to the exhaust pipe and includes the particulate filter 53, and a cover that is provided around the exhaust purifying device main body 40 and covers the exhaust purifying device main body 40 from the outside. 42, an inner heat insulating material 41 provided between the exhaust purification device main body 40 and the cover 42, and disposed so that an air layer 78, 79 is formed between at least one of the exhaust purification device main body 40 and the cover 42. It is equipped with. Therefore, since the periphery of the exhaust purification device main body 40 is covered with the inner heat insulating material 41 and the air layers 78 and 79, heat radiation from the exhaust purification device main body 40 to the outside can be suppressed, and the exhaust purification device 14 is connected to the engine 10. It is possible to prevent adverse effects (heat damage) due to heat on peripheral components while being arranged in the vicinity. In addition, it is possible to advantageously regenerate the particulate filter 53 by suppressing heat radiation from the outer peripheral portion of the particulate filter 53 and making it easy to keep the temperature of the particulate filter 53 uniformly raised and maintained. This is advantageous for preventing the exhaust gas purification effect from being lowered. In addition, the load on the engine 10 due to heat radiation from the exhaust purification device 14 (particulate filter 53) can be reduced, and the heat balance performance in the hood 5 can be ensured.

  Further, the exhaust purification device 14 includes an outer heat insulating material 43 provided around the cover 42. Therefore, since the periphery of the exhaust purification device main body 40 is doubly covered by the inner heat insulating material 41 and the outer heat insulating material 43 and further covered by the air layers 78 and 79, heat radiation from the exhaust purification device main body 40 to the outside is effective. Therefore, it is possible to effectively prevent thermal damage to the peripheral components while disposing the exhaust purification device 14 in the vicinity of the engine 10. Further, by suppressing the heat radiation from the outer peripheral portion of the particulate filter 53 and making it easy to keep the temperature of the entire particulate filter 53 uniformly raised, it becomes possible to make the regeneration of the particulate filter 53 more advantageous. . This is advantageous for preventing the exhaust gas purification effect from being lowered.

  Below, the exhaust gas purification device 140 which is 2nd embodiment of the exhaust gas purification device of this invention is demonstrated with reference to FIG. Of the members related to the exhaust purification device 140, members having substantially the same configuration as the exhaust purification device 14 are denoted by the same reference numerals, and description thereof is omitted. In FIG. 12, the configuration of the exhaust emission control device 140 is shown after omitting the outer heat insulating material 43 provided around the cover 25.

  The exhaust purification device 140 is mainly different from the exhaust purification device 14 in that the cover 25 can be divided into a plurality (three) of a right cover 64, a left cover 65, and a rear cover 28.

  At the rear end of the right cover 64 and the rear end of the left cover 65, flange portions 26 and 26 for attaching the rear lid 28 are provided. The flange portions 26 and 26 are provided so as to protrude outward in the radial direction of the cover 25. In the flange portions 26, 26, through holes for penetrating bolts 29, 29, which will be described later, are formed at predetermined intervals in the radial direction. The flange portions 26 and 26 form an integral surface when the right cover 64 and the left cover 65 are fastened with bolts 89, 89, and nuts and attached to the periphery of the exhaust purification apparatus main body 40.

  The rear lid 28 is a cylindrical member having a substantially hexagonal shape with a lid and no bottom when viewed from the front (back view). A flange portion 27 is provided at the front end of the rear lid 28. The flange portion 27 is provided so as to protrude outward in the radial direction of the cover 25, and is provided so as to face the flange portions 26 and 26. In the flange portion 27, through holes for penetrating bolts 29, 29... Described later are formed at predetermined intervals in the radial direction. The through hole of the flange portion 27 is formed at a position where it can be matched with the through hole of the flange portions 26 and 26 in the rear view (front view).

  The rear lid 28 has bolts 29 inserted into the through holes and nuts (not shown) in a state where the through holes of the flange portions 26 and 26 and the through holes of the flange portion 27 are aligned. By fastening, it can be fixed to the flange portions 26 and 26. Therefore, the rear cover 28 of the cover 25 can be attached and detached from the rear of the right cover 64 and the left cover 65 using bolts 29, 29... And nuts.

  A rear lid 59 of the inner heat insulating material 41 is fixed to the front surface of the rear lid 28 (not shown). A rear cover 71 of the outer heat insulating material 43 is fixed to the rear surface of the rear cover 28 (not shown). Thus, when the rear cover 28 of the cover 25 is attached / detached from the rear ends (flange portions 26) of the right cover 64 and the left cover 65, the rear cover 59 and the rear cover 71 can be attached / detached simultaneously.

  With this configuration, in the exhaust purification device 140 of the present embodiment, the rear cover 28 is removed from the rear of the exhaust purification device 140 and then the third housing portion 82 provided in the exhaust purification device main body 40. By removing the second housing portion 81 from the rear, the particulate filter 53 can be pulled out of the housing 50. Therefore, it is possible to perform maintenance or the like by removing the particulate filter 53 while the exhaust purification device 140 is connected to the engine 10 via the inlet side exhaust pipe 31. That is, the particulate filter 53 can be easily removed from the exhaust purification device 140, and the work load during maintenance is reduced.

  In the exhaust purification device 140 having such a configuration, the operator does not touch the side surface of the exhaust purification device main body 40 during maintenance. Further, since the rear cover 28 is covered with the outer heat insulating material 43 (rear cover 71) and the inner heat insulating material 41 (rear cover 59), even when the rear cover 28 is at a high temperature, the operator can use this rear cover. There is little risk of touching 28 directly. Therefore, it is possible to prevent a situation in which an operator touches the exhaust purification device 140 and burns during maintenance.

  As described above, the exhaust emission control device 140 is configured such that the cover 25 can be divided into a plurality of parts (the right cover 64, the left cover 65, and the rear cover 28). Therefore, the rear cover 28 is removed from the rear of the exhaust purification device 140 while the exhaust purification device 140 remains connected to the engine 10 via the inlet side exhaust pipe 31, and then the exhaust purification device main body 40 is provided with the first. By removing the three housing portions 82 and the second housing portion 81 from the rear, the particulate filter 53 can be pulled out of the housing 50 and removed, so that maintenance such as cleaning of the particulate filter 53 is easy. Can be performed. Further, since the side surface of the exhaust purification device main body 40 is covered by the side surface body 60 of the inner heat insulating material 41, the cover 42, and the side surface body 72 of the outer heat insulating material 43, the operator touches the side surface of the exhaust purification device main body 40 during maintenance. Nothing will happen. Therefore, it is possible to prevent a situation where the operator touches the exhaust purification device 140 and burns.

  The cover 25 provided in the exhaust purification apparatus 140 according to the present embodiment is configured to be divided into the right cover 64, the left cover 65, and the rear cover 28, but the present invention is not limited to this. That is, for example, instead of the right side cover and the left side cover, a front side cover and a rear side cover may be provided, and the cover may be divided into a plurality of parts in a direction perpendicular to the axial direction.

DESCRIPTION OF SYMBOLS 1 Excavator 10 Engine 14 Exhaust gas purification device 28 Rear cover 31 Inlet side exhaust pipe 35 Flywheel case 40 Exhaust gas purification device body 41 Inner heat insulating material 42 Cover 43 Outer heat insulating material 53 Particulate filter (53) 64 Right side cover 65 Left side cover 78 Air layer 79 Air layer

Claims (1)

An exhaust pipe of the engine (10) is constituted by an inlet side exhaust pipe (31) and an outlet side exhaust pipe (56), and is located in the middle part between the inlet side exhaust pipe (31) and the outlet side exhaust pipe (56). An exhaust purification device (14) is interposed in the vicinity of the engine (10). The exhaust purification device (14) includes an exhaust purification device main body (40), an inner heat insulating material (41), and a cover (42). And the outer heat insulating material (43), and the exhaust purification device main body (40) includes a casing (50) including an oxidation catalyst (52) and a particulate filter (53) inside, An inlet side exhaust pipe (31) and an outlet side exhaust pipe (56) are connected, and the inner heat insulating material (41) is made of a heat insulating material such as glass wool or ceramic, and the exhaust purification device main body (40). The cover (42) is made of metal or other resistant material. It is composed of a material made of a material having a right side cover (64) and a left side cover (65), and can be divided into right and left parts, covering the inner heat insulating material (41) and the outer heat insulating material. The material (43) is made of a heat insulating material such as glass wool or ceramic, covers the periphery of the cover (42), and the outer peripheral surface of the exhaust purification device main body (40) and the inner heat insulating material (41). ) To form an air layer (78), and the gap between the outer peripheral surface of the inner heat insulating material (41) and the inner peripheral surface of the cover (42). And an air layer (79) is formed .

Images