JP2013160146A - Exhaust emission control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent breakage of a soot filter 40, when foreign matter such as a bar is inserted from an exhaust gas outlet 38a, for example, for reducing a pressure loss or by mischief, in a structure having the exhaust gas outlet 38a opened in a cover body for closing the exhaust downstream side of an exhaust emission control device 2, without installing a muffler on the exhaust downstream side.SOLUTION: An exhaust emission control device 2 includes a plurality of filter bodies 39 and 40 for purifying exhaust gas exhausted by an engine 1, and a purification casing 38 containing the plurality of filter bodies 39 and 40. An exhaust gas outlet 38a is opened in a cover body 100 for closing the exhaust downstream side of the purification casing 38. A baffle plate 101 is arranged on the inner surface side of the cover body 100, for preventing a foreign matter from being inserted into the purification casing 38.

Description

  The present invention relates to an exhaust gas purification device mounted on a diesel engine or the like, and more particularly to an exhaust gas purification device that removes particulate matter (soot, particulates) and the like contained in exhaust gas. .

  Conventionally, a diesel particulate filter (hereinafter referred to as DPF) is provided as an exhaust gas purification device in an exhaust path of a diesel engine (hereinafter simply referred to as an engine), and exhaust gas discharged from the engine is purified by the DPF. Is known (see Patent Document 1). In DPF, a technique is known in which an inner case is provided in a double structure inside an outer case, and an oxidation catalyst or a soot filter is built in the inner case (see, for example, Patent Document 2). Furthermore, in the DPF, a technique is also known in which a case containing an oxidation catalyst and a case containing a soot filter are detachably connected via a flange fastened by a bolt (see, for example, Patent Documents 3 and 4).

JP 2004-263593 A JP 2005-194949 A JP 2009-228516 A JP 2009-91982 A

  By the way, in the case where a silencer is not attached to the exhaust downstream side (exit side) of the DPF and an exhaust gas outlet is opened in a lid that closes the exhaust downstream side, the silencer is connected to the exhaust gas outlet via an exhaust pipe or the like A vessel will be attached. However, if the exhaust pipe is removed, the soot filter in the DPF can be seen from the exhaust gas outlet, so if a foreign object such as a rod is inserted from the exhaust gas outlet, for example, to reduce pressure loss, etc. There was a concern that the soot filter could easily be destroyed.

  This invention makes it a technical subject to provide the exhaust-gas purification apparatus which examined and improved the above present condition.

  The invention according to claim 1 is an exhaust gas purification device comprising a plurality of filter bodies that purify exhaust gas discharged from an engine and a purification casing that houses the plurality of filter bodies, and covers the exhaust downstream side of the purification casing. An exhaust gas outlet is opened in the lid, and a baffle plate for preventing foreign matter from being inserted into the purification casing is provided on the inner surface side of the lid.

  According to a second aspect of the present invention, in the exhaust gas purifying apparatus according to the first aspect, an exhaust pressure sensor is connected to the purification casing via an exhaust pressure sensor pipe, and the exhaust pressure sensor pipe is connected to one end side of the exhaust pressure sensor pipe. An anti-rotation body is provided on a certain fastening boss body, and the anti-rotation body is engaged with the purification casing to fasten the fastening boss body.

  According to the first aspect of the present invention, in an exhaust gas purification apparatus comprising a plurality of filter bodies that purify exhaust gas exhausted by an engine and a purification casing that houses the plurality of filter bodies, the exhaust downstream side of the purification casing is An exhaust gas outlet is opened in the lid to be closed, and a baffle plate is provided on the inner surface side of the lid to prevent foreign matter from being inserted into the purification casing. Even if the pipe is removed, the exhaust gas outlet is covered with the baffle plate from the inside, and the presence of the baffle plate can prevent foreign matter from being inserted into the purification casing. Therefore, it is possible to prevent the filter body in the purification casing from being destroyed by inserting foreign matter such as a rod from the exhaust gas outlet by, for example, reducing pressure loss or mischief.

  According to a second aspect of the present invention, an exhaust pressure sensor is connected to the purification casing via an exhaust pressure sensor pipe, and a fastening body is provided on a fastening boss body on one end side of the exhaust pressure sensor pipe. And when the fastening boss body is fastened to the purification casing, the rotation prevention body is locked to the purification casing. The fastening boss body may be screwed in until the rotation stopper is locked. Then, the exhaust pressure sensor pipe can be fixed to the purification casing after being always maintained in a predetermined posture, and the assembly workability of the exhaust pressure sensor pipe can be greatly improved.

It is the perspective view which looked at the engine from diagonally forward. It is a left view of an engine. It is a right view of an engine. It is a top view of an engine. It is a front view of an engine. It is a rear view of an engine. It is a section explanatory view of an exhaust gas purification device. It is the perspective view which looked at the cover body from the inner surface side. It is a principal part enlarged view of an exhaust-gas purification apparatus.

  DESCRIPTION OF EMBODIMENTS Embodiments embodying the present invention will be described below with reference to the drawings.

  First, a schematic structure of the common rail engine 1 will be described with reference to FIGS. In the following description, both sides parallel to the crank axis (the sides on both sides of the crank axis) are left and right, the cooling fan 9 arrangement side is the front side, the flywheel housing 10 arrangement side is the rear side, and the exhaust manifold 7 The arrangement side is referred to as the left side, and the intake manifold 6 arrangement side is referred to as the right side, and these are used as a reference for the positional relationship between the four sides and the top and bottom in the engine 1 for convenience.

  As shown in FIGS. 1 to 6, an engine 1 as a prime mover mounted on a work machine such as an agricultural machine or a construction / civil engineering machine includes a continuously regenerative exhaust gas purification device 2 (a diesel particulate filter (DPF)). The exhaust gas purification device 2 removes particulate matter (PM) in the exhaust gas discharged from the engine 1 and reduces carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas. Is done.

  The engine 1 includes a cylinder block 4 that incorporates an engine output crankshaft 3 and a piston (not shown). A cylinder head 5 is mounted on the cylinder block 4. An intake manifold 6 is disposed on the right side surface of the cylinder head 5. An exhaust manifold 7 is disposed on the left side surface of the cylinder head 5. A head cover 8 is disposed on the upper side surface of the cylinder head 5. A cooling fan 9 is provided on the front side surface of the cylinder block 4. A flywheel housing 10 is provided on the rear side of the cylinder block 4. A flywheel 11 is disposed in the flywheel housing 10.

  A flywheel 11 is pivotally supported on the crankshaft 3 (engine output shaft). The working unit (backhoe, forklift, etc.) is configured to take out the power of the engine 1 via the crankshaft 3 to the working part. An oil pan 12 is disposed on the lower surface of the cylinder block 4. Lubricating oil in the oil pan 12 is supplied to each lubricating portion of the engine 1 through an oil filter 13 disposed on the side surface of the cylinder block 4.

  A fuel supply pump 14 for supplying fuel is attached to the side of the cylinder block 4 above the oil filter 13 (below the intake manifold 6). The engine 1 is provided with injectors 15 for four cylinders each having an electromagnetic opening / closing control type fuel injection valve (not shown). A fuel tank (not shown) mounted on the work machine is connected to each injector 15 via a fuel supply pump 14, a cylindrical common rail 16 and a fuel filter 17.

  The fuel in the fuel tank is pumped from the fuel supply pump 14 to the common rail 16 via the fuel filter 17, and high-pressure fuel is stored in the common rail 16. By controlling the fuel injection valves of the injectors 15 to open and close, the high-pressure fuel in the common rail 16 is injected from the injectors 15 into the cylinders of the engine 1. An engine starter 18 is provided in the flywheel housing 10.

  A cooling water pump 21 for lubricating the cooling water is disposed coaxially with the fan shaft of the cooling fan 9 at a portion on the left side of the front surface of the cylinder block 4. The rotation of the crankshaft 3 drives the cooling water pump 21 together with the cooling fan 9 via the cooling fan driving V-belt 22. Cooling water in a radiator (not shown) mounted on the work machine is supplied to the cooling water pump 21 by driving the cooling water pump 21. Then, cooling water is supplied to the cylinder block 4 and the cylinder head 5 to cool the engine 1. An alternator 23 is provided on the left side of the cooling water pump 21.

  Engine leg mounting portions 24 are respectively provided on the left and right side surfaces of the cylinder block 4. Each engine leg mounting portion 24 is bolted to an engine leg (not shown) having vibration-proof rubber. The engine 1 is supported by a work machine (an engine mounting chassis such as a backhoe or a forklift car) via the respective engine legs.

  Further, the EGR device 26 (exhaust gas recirculation device) will be described. An air cleaner (not shown) is connected to an inlet portion of the intake manifold 6 protruding upward via an EGR device 26 (exhaust gas recirculation device). Fresh air (external air) is sent from the air cleaner to the intake manifold 6 via the EGR device 26.

  The EGR device 26 mixes a part of exhaust gas of the diesel engine (EGR gas from the exhaust manifold) and fresh air (external air from the air cleaner) and supplies it to the intake manifold 6 (collector) (illustrated). An intake throttle member (not shown) for communicating the EGR main body case 27 with the air cleaner, a recirculation exhaust gas pipe 30 as a recirculation line connected to the exhaust manifold 7 via an EGR cooler 29, An EGR valve member (not shown) for communicating the EGR main body case with the circulation exhaust gas pipe 30 is provided.

  That is, the intake manifold 6 and the intake air throttle member for introducing fresh air are connected via the EGR main body case. The EGR main body case communicates with the outlet side of the recirculated exhaust gas pipe 30 extending from the exhaust manifold 7. The EGR main body case is detachably bolted to the inlet portion of the intake manifold 6.

  Further, the outlet side of the recirculation exhaust gas pipe 30 is connected to the EGR device 26. The inlet side of the recirculated exhaust gas pipe 30 is connected to the exhaust manifold 7 via an EGR cooler 29. The amount of EGR gas supplied to the EGR device 26 is adjusted by adjusting the opening of an EGR valve (not shown) in the EGR device 26.

  With the above configuration, fresh air (external air) is supplied from the air cleaner to the EGR device 26 through the intake throttle member, while EGR gas (exhaust from the exhaust manifold) is supplied from the exhaust manifold 7 to the EGR device 26. A part of the exhaust gas). After the fresh air from the air cleaner and EGR gas from the exhaust manifold 7 are mixed in the EGR device 26, the mixed gas in the EGR device 26 is supplied to the intake manifold 6. That is, a part of the exhaust gas discharged from the engine 1 to the exhaust manifold 7 is recirculated from the intake manifold 6 to the engine 1, so that the maximum combustion temperature at the time of high load operation decreases, and NOx ( Emissions of nitrogen oxides are reduced.

Next, the exhaust gas purification device 2 will be described. The exhaust gas purification device 2 includes a purification casing 38 having a purification inlet pipe 36. Inside the purification casing 38, a diesel oxidation catalyst 39 (filter body) such as platinum that generates nitrogen dioxide (NO ₂ ), and a honeycomb that continuously oxidizes and removes the collected particulate matter (PM) at a relatively low temperature. A soot filter 40 (filter body) having a structure is arranged in series in the exhaust gas movement direction. A silencer is connected to the exhaust gas outlet 38a of the purification casing 38 via an exhaust pipe (not shown), and the exhaust gas is discharged outside the machine via the silencer.

With the above configuration, nitrogen dioxide (NO ₂ ) generated by the oxidation action of the diesel oxidation catalyst 39 is supplied into the soot filter 40 from one side end face (intake side end face). Particulate matter (PM) contained in the exhaust gas of the engine 1 is collected by the soot filter 40 and continuously oxidized and removed by nitrogen dioxide (NO ₂ ). In addition to the removal of particulate matter (PM) in the exhaust gas of the engine 1, the content of carbon monoxide (CO) and hydrocarbon (HC) in the exhaust gas of the engine 1 is reduced.

  A purification inlet pipe 36 is provided on the outer peripheral portion of the purification casing 38 on the exhaust upstream side. A lid 100 is welded and fixed to the exhaust downstream end of the purification casing 38. An end of the purification casing 38 on the exhaust downstream side is closed by the lid 100. An exhaust gas outlet 38 a is opened at a substantially central portion of the lid 100. A baffle plate 101 that prevents foreign matter from being inserted into the purification casing 38 is provided on the inner surface side of the lid 100 (see FIGS. 7 and 8). The baffle plate 101 is configured as a breathable cover made of punching metal or wire mesh. The baffle plate 101 of the embodiment has many small holes. Even if the exhaust pipe (not shown) is removed, the exhaust gas outlet 38a is covered with the baffle plate 101 from the inside, and the presence of the baffle plate 101 can prevent foreign matter from being inserted into the purification casing 38. Therefore, it is possible to prevent the soot filter 40 in the purification casing 38 from being destroyed by inserting foreign matter such as a rod from the exhaust gas outlet 38a by, for example, reducing pressure loss or mischief.

  A thermistor type exhaust gas temperature sensor 42 is attached to the purification casing 38. Three sensor pipes 42 a to 42 c extend from the exhaust gas temperature sensor 42. The detection parts at the tips of the sensor pipes 42a to 42c respectively enter the exhaust upstream side of the diesel oxidation catalyst 39, between the diesel oxidation catalyst 39 and the soot filter 40, and to the exhaust downstream side of the soot filter 44. The exhaust gas temperature in each space is detected. The exhaust gas temperature sensor 42 converts the exhaust gas temperature into an electrical signal and outputs it to an engine controller (not shown).

  Further, an exhaust pressure sensor 44 is attached to the purification casing 38. An exhaust pressure sensor 44 detects the pressure difference of the exhaust gas between the upstream side and the downstream side of the soot filter 40. The pressure difference of the exhaust gas is converted into an electrical signal and output to an engine controller (not shown). Based on the exhaust pressure difference between the upstream side and the downstream side of the soot filter 40, the accumulation amount of particulate matter in the soot filter 40 is calculated, and the clogged state in the soot filter 40 can be grasped.

  As shown in FIGS. 1 to 6, the sensor bracket 46 is bolted to the outlet holding flange 45 of the purification casing 38, and the sensor bracket 46 is disposed on the outer surface side of the purification casing 38. An exhaust pressure sensor 44 integrally provided with an electrical wiring connector is attached to the sensor bracket 46. An exhaust pressure sensor 44 is disposed on the outer surface of the purification casing 38. The exhaust pressure sensor 44 is connected to one end side of an upstream sensor pipe 47 and a downstream sensor pipe 48 as exhaust pressure sensor pipes. The upstream and downstream sensor piping boss bodies 49 and 50 are arranged in the purification casing 38 so as to sandwich the soot filter 40 in the purification casing 38. Fastening boss bodies 105, 106 provided on the other end sides of the sensor pipes 47, 48 are fastened to the sensor pipe boss bodies 49, 50 via pipe joint bolts 107.

  The purification casing 38 of the embodiment has a double cylinder structure (see FIG. 7). Each sensor piping boss body 49, 50 is welded and fixed to the inner cylinder side of the purification casing 38 in such a positional relationship as to sandwich the soot filter 44. The outward projecting ends of the sensor pipe boss bodies 49 and 50 project radially outward from opening holes 109 and 110 formed on the outer cylinder side (outer peripheral side) of the purification casing 38. The fastening boss bodies 105 and 106 of the sensor pipes 47 and 48 are provided with hook-shaped detent bodies 111 and 112, respectively. When fastening the fastening boss bodies 105, 106 to the sensor piping boss bodies 49, 50 via the pipe joint bolts 107, the rotation prevention bodies 111, 112 are locked to the edges of the opening holes 109, 110 of the purification casing 38. Until then, the fastening boss bodies 105 and 106 are screwed into the sensor piping boss bodies 49 and 50. Accordingly, the fastening boss bodies 105 and 106 are fixed to the sensor pipe boss bodies 49 and 50 in the same posture in which the sensor pipes 47 and 48 always extend toward the sensor bracket 46 (and thus the exhaust pressure sensor 44). Assembling workability of the sensor pipes 47 and 48 can be remarkably improved.

  With the above configuration, the difference between the exhaust gas pressure on the inflow side of the soot filter 40 and the exhaust gas pressure on the outflow side of the soot filter 40 (exhaust gas differential pressure) is detected via the exhaust pressure sensor 44. Since the residual amount of particulate matter in the exhaust gas collected by the soot filter 40 is proportional to the differential pressure of the exhaust gas, the exhaust gas is increased when the amount of particulate matter remaining in the soot filter 40 increases more than a predetermined amount. Based on the detection result of the pressure sensor 44, regeneration control for reducing the amount of particulate matter in the soot filter 40 (for example, control for increasing the exhaust temperature) is executed. When the residual amount of the particulate matter further increases beyond the regeneration controllable range, the cleaning casing 38 is detached and disassembled, the soot filter 40 is cleaned, and the particulate matter is removed manually. Is called.

  The electrical wiring connector 53 of the exhaust gas temperature sensor 42 is fixed to the sensor bracket 46. Each connector 53 is supported in a posture in which the connection directions of the electrical wiring connector of the exhaust pressure sensor 44 and the electrical wiring connector 53 of the exhaust gas temperature sensor 42 are directed in the same direction.

  Next, a structure in which the exhaust gas purification device 2 is attached to the engine 1 will be described. A turbocharger 91 is provided in the exhaust manifold 7. The housing support 92 is bolted to the exhaust manifold 7 and the turbocharger 91. The mounting position of the exhaust gas purification device 2 in the front-rear direction with respect to the housing support 92 can be adjusted to be movable back and forth. The exhaust gas of the engine 1 is supplied from the exhaust manifold 7 to the exhaust gas purification device 2 through the hollow portion of the housing support 92.

  Further, an inlet side bracket body 93 and an outlet side bracket body 94 are provided. The exhaust gas moving direction of the exhaust gas purifying device 2 and the crankshaft three-axis core line (output shaft core line) of the engine 1 are formed in parallel. The inlet side bracket body 93 and the outlet side bracket body 94 are formed in a plate shape that is wide in the direction intersecting with the triaxial core line of the crankshaft.

  The bifurcated lower end portion of the outlet side bracket body 94 is bolted to the front surface of the cylinder head 5, and the lower end portion of the inlet side bracket body 93 is bolted to the rear surface of the cylinder head 5. An outlet side bracket body 94 and an inlet side bracket body 93 are erected on the two surfaces of the front surface and the rear surface of the cylinder head 5. By the outlet side bracket body 94 and the inlet side bracket body 93, the cylinder head 5 of the engine 1 supports the exhaust gas inlet side and the exhaust gas outlet side of the gas purification housing 60, respectively.

1 Engine 2 Exhaust gas purification device 38 Purification casing 38a Exhaust gas outlet 39 Diesel oxidation catalyst (filter body)
40 Soot filter (filter body)
44 Exhaust pressure sensor 46 Sensor bracket 47 Upstream sensor pipe 48 Downstream sensor pipe 49, 50 Sensor piping boss body 100 Lid body 101 Baffle plates 105, 106 Fastening boss body 107 Pipe joint bolts 109, 110 Opening holes 111, 112 Non-rotating body

Claims (2)

In an exhaust gas purification device comprising a plurality of filter bodies for purifying exhaust gas discharged from an engine, and a purification casing containing the plurality of filter bodies,
An exhaust gas outlet is opened in the lid that closes the exhaust downstream side of the purification casing, and a baffle plate that prevents foreign matter from being inserted into the purification casing is provided on the inner surface of the lid.
Exhaust gas purification device. An exhaust pressure sensor is connected to the purification casing via an exhaust pressure sensor pipe,
The fastening boss body on one end side of the exhaust pressure sensor pipe is provided with a rotation preventing body, and is configured to fasten the fastening boss body by locking the rotation prevention body to the purification casing.
The exhaust gas purification apparatus according to claim 1.

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