WO2010071082A1

WO2010071082A1 - Engine device

Info

Publication number: WO2010071082A1
Application number: PCT/JP2009/070726
Authority: WO
Inventors: 謙太齋藤; 洋泰西川
Original assignee: ヤンマー株式会社
Priority date: 2008-12-19
Filing date: 2009-12-11
Publication date: 2010-06-24

Abstract

An engine (70) equipped with an exhaust gas purifying device (1) is efficiently mounted on a working vehicle (120) having a limited mounting space. The engine device is an engine device for mounting on a traveling machine body (124) of the working vehicle (120). The engine device is provided with a radiator (134) for cooling the engine (70) by water and located on one side of the engine (70) provided below an operating seat (128) of the traveling machine body (124), and the engine device is also provided with a cooling fan (76) for cooling the engine (70) and the radiator (134). The exhaust gas purifying device (1) for purifying exhaust gas from the engine (70) is provided below the radiator (134) and the cooling fan (76).

Description

Engine equipment

The present invention relates to an engine device used in a work vehicle such as a backhoe, a forklift, or a tractor, and more particularly to an arrangement structure of an engine, an exhaust gas purification device, and the like on a fuselage.

Conventionally, a diesel particulate filter (or NOx catalyst) or the like is provided as an exhaust gas purification device (post-treatment device) in the exhaust path of the diesel engine, and exhaust gas discharged from the diesel engine is supplied to a diesel particulate filter ( Alternatively, a technology for purifying with a NOx catalyst or the like is known (see Patent Document 1, Patent Document 2, and Patent Document 3). Further, a technique in which a filter case (inner case) is provided in a casing (outer case) and a particulate filter is disposed in the filter case is also known (see Patent Document 4).

JP 2000-145430 A Japanese Patent Laid-Open No. 2003-27922 JP 2008-82201 A JP 2001-173429 A

By the way, the diesel engine has wide versatility and is used in various fields such as construction machines, agricultural machines, and ships. Diesel engine mounting space varies depending on the vehicle on which it is mounted, but especially on work vehicles such as forklifts and backhoes, the aircraft itself must be made compact in order to minimize the turning radius to prevent contact with the surroundings. In many cases, the mounting space is limited (narrow).

On the other hand, in the exhaust gas purifying apparatus described above, it is functionally desirable that the temperature of the exhaust gas passing through the exhaust gas purifying apparatus is high (for example, 300 ° C. or higher), so the exhaust gas purifying apparatus is attached to the diesel engine. There is a request to want.

However, in order to apply a diesel engine with an exhaust gas purification device to a work vehicle, not only a diesel engine with an exhaust gas purification device but also various parts such as a radiator and an air cleaner are efficiently arranged in a narrow mounting space. There must be. In addition to the problem of mounting space limitations, engine vibration due to driving is easily transmitted directly to the exhaust gas purification device, or when cooling air from a cooling fan provided in the diesel engine directly hits the exhaust gas purification device. Also, there is a problem that the exhaust gas purifying device, and thus the exhaust gas temperature, may be lowered.

Therefore, the present invention aims to improve such a current situation.

In order to achieve the above object, an invention according to claim 1 is an engine device mounted on a traveling machine body of a work vehicle, wherein engine water cooling is provided on one side of an engine disposed below a control seat in the traveling machine body. And an exhaust gas purifying device for purifying exhaust gas from the engine is disposed below the radiator and the cooling fan. It is that.

According to a second aspect of the present invention, in the engine device according to the first aspect, a filter support that supports the exhaust gas purifying device at a pair of engine leg mounting portions located near the cooling fan on both side surfaces of the engine. And the exhaust gas purification device is connected to each engine leg mounting portion via each filter support.

According to a third aspect of the present invention, in the engine device according to the first aspect, the exhaust gas purifying device is disposed below the radiator and the cooling fan in a form that is long in a direction orthogonal to the output shaft of the engine. The exhaust gas moves in the exhaust gas purification device along the orthogonal direction.

According to a fourth aspect of the present invention, in the engine device according to the first aspect, the radiator and the cooling fan are located at a high position near the counterweight between the control seat and a counterweight disposed behind the control seat. On the other hand, the exhaust gas purifying device is arranged so as to face the oil pan arranged below the radiator and the cooling fan and on the lower surface side of the engine.

According to a fifth aspect of the present invention, in the engine device according to the second aspect, a windshield that blocks cooling air from the cooling fan toward the exhaust gas purification device is disposed between the exhaust gas purification device and the cooling fan. It has been done.

According to a sixth aspect of the present invention, in the engine device according to the fifth aspect, the windshield is attached to the casing of the exhaust gas purification device.

The invention of claim 7 is the engine device according to claim 5, wherein the exhaust manifold provided in the engine and the exhaust gas purification device are connected via a relay exhaust pipe, and the relay exhaust pipe and the Between the cooling fan, an exhaust pipe windshield for blocking cooling air from the cooling fan toward the relay exhaust pipe is disposed.

According to an eighth aspect of the present invention, in the engine device according to the fifth aspect, an exhaust manifold provided in the engine and the exhaust gas purification device are connected via a relay exhaust pipe, and the relay exhaust pipe is insulated. It is a structure.

According to the present invention, an engine device mounted on a traveling machine body of a work vehicle, on one side of an engine disposed below a control seat in the traveling machine body, a radiator for engine water cooling, the engine, and the engine A cooling fan for cooling the radiator, and an exhaust gas purifying device for purifying exhaust gas from the engine is disposed below the radiator and the cooling fan, so the radiator and the cooling fan The space below can be effectively used as an arrangement space for the exhaust gas purification device, and the utilization efficiency of the internal space of the traveling machine body can be improved.

Further, since the exhaust gas purification device is disposed at a position as close as possible to the engine (particularly the exhaust manifold) and where the cooling air from the cooling fan is difficult to hit, the exhaust gas purification device using the cooling air, As a result, the fall of the exhaust gas temperature in the inside can be suppressed, and the exhaust gas purification performance of the exhaust gas purification device can be easily maintained in an appropriate state. In addition, since the exhaust gas purification device, which is heavy, for example, from a silencer or the like, is disposed below the cooling fan, the center of gravity of the engine is lowered, and vibration isolation can be improved.

According to a second aspect of the present invention, in the engine device according to the first aspect, the filter that supports the exhaust gas purifying device on a pair of engine leg mounting portions located on the side of the cooling fan on both side surfaces of the engine. Since the exhaust gas purifying device is connected to each engine leg mounting portion via each filter support, the exhaust gas purifying device is provided as one of the components of the engine. It is possible to arrange the gas purification device with high rigidity, eliminate the need for exhaust gas countermeasures for each device such as a work vehicle, and improve the versatility of the engine.

That is, the exhaust gas purification device can be supported with high rigidity by using the high rigidity portion of the engine, and damage to the exhaust gas purification device due to vibration or the like can be prevented. In addition, the exhaust gas purifying device can be assembled and shipped in the engine at the manufacturing site of the engine, and there is an advantage that the engine and the exhaust gas purifying device can be configured compactly. As described above, the engine can be shipped with the exhaust gas purification device incorporated therein, so that it is possible to eliminate the trouble of shipping application for each work vehicle equipped with the engine, and the manufacturing cost can be reduced.

According to a third aspect of the present invention, in the engine device according to the first aspect, the exhaust gas purifying device is disposed below the radiator and the cooling fan in a form that is long in a direction perpendicular to the output shaft of the engine. Since the exhaust gas moves in the exhaust gas purification device along the orthogonal direction, the exhaust gas is directed below the cooling fan in the left-right direction orthogonal to the engine output shaft. The purification device can be extended. For this reason, it is possible to easily improve the exhaust gas purification performance and add a silencing function. Since the size of the exhaust gas purification device in the direction of the engine output shaft can be made compact, it is possible to easily secure an arrangement space for the exhaust gas purification device below the cooling fan.

According to a fourth aspect of the present invention, in the engine device according to the first aspect, the radiator and the cooling fan are located at a high position near the counterweight between the control seat and a counterweight disposed behind the control seat. On the other hand, since the exhaust gas purifying device is disposed so as to face the oil pan disposed below the radiator and the cooling fan and on the lower surface side of the engine, And an internal space formed between the counterweight and the exhaust gas purifying device can be effectively used as an arrangement space for the exhaust gas purifying device. Suppressing the decrease in gas temperature and maintaining the exhaust gas purification performance of the exhaust gas purification device in an appropriate state There is an effect that easy.

According to a fifth aspect of the present invention, in the engine device according to the second aspect, a windshield for blocking cooling air from the cooling fan toward the exhaust gas purification device is provided between the exhaust gas purification device and the cooling fan. Since it is disposed, it is possible to prevent the cooling air from the cooling fan from directly hitting the exhaust gas purification device, and it is possible to reliably suppress a decrease in the exhaust gas purification device, and hence the exhaust gas temperature inside the exhaust gas purification device due to the cooling air. . Therefore, the exhaust gas purification performance of the exhaust gas purification device can be maintained appropriately. In particular, since the exhaust gas purifying device is arranged below the cooling fan, it is difficult for the cooling air to hit only by the arrangement mode, and the presence of the windshield can reliably suppress a decrease in the exhaust gas temperature due to the cooling air. .

According to the invention of claim 6, in the engine device according to claim 5, since the windshield is attached to the casing of the exhaust gas purification apparatus, the windshield using the casing of the exhaust gas purification apparatus The support structure can be easily configured. Further, since the windshield can be incorporated in the configuration of the exhaust gas purification device, the workability of assembling exhaust system parts including the exhaust gas purification device can be improved.

According to the invention of claim 7, in the engine device according to claim 5, the exhaust manifold provided in the engine and the exhaust gas purification device are connected via a relay exhaust pipe, Between the cooling fan, an exhaust pipe wind shield that blocks cooling air from the cooling fan toward the relay exhaust pipe is disposed, so even if the relay exhaust pipe passes through the vicinity of the cooling fan, It is possible to prevent the cooling air from the cooling fan from directly hitting the relay exhaust pipe, and it is possible to reliably suppress a decrease in the exhaust gas temperature in the relay exhaust pipe due to the cooling air.

According to the invention of claim 8, in the engine device according to claim 5, since the exhaust manifold provided in the engine and the exhaust gas purification device are connected via the relay exhaust pipe, the relay exhaust pipe The exhaust pipe windshield support structure can be easily constructed using the outer peripheral surface of the exhaust pipe. In addition, since the exhaust pipe windshield can be incorporated in the configuration of the relay exhaust pipe, the workability of assembling exhaust system parts including the relay exhaust pipe can be improved. In addition, since the relay exhaust pipe has a heat insulating structure, a decrease in the exhaust gas temperature in the relay exhaust pipe due to cooling air is extremely suppressed. For this reason, it is not necessary to consider the adverse effect of the cooling air on the exhaust gas passing through the relay exhaust pipe, and the dead space below the cooling fan can be effectively used as the arrangement space of the exhaust gas purification device.

It is a front view sectional view of the exhaust-gas purification apparatus concerning an embodiment. It is the same external appearance bottom view. It is the left view seen from the exhaust gas inflow side. It is right side sectional drawing seen from the exhaust gas discharge side. FIG. 2 is an exploded front sectional view of FIG. 1. It is a front view expanded sectional view of the exhaust gas discharge side. It is a side view enlarged sectional view on the same exhaust gas discharge side. It is a left view of a diesel engine. It is a top view of a diesel engine. It is a front view of a diesel engine. It is an expanded sectional view of a relay exhaust pipe. It is a functional block diagram of a controller. It is a flowchart which shows an example of control. It is a side view of a backhoe. It is a top view of a backhoe. It is a side view of a forklift car. It is a top view of a forklift car.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the exhaust gas inflow side is simply referred to as the left side, and the exhaust gas discharge side is also simply referred to as the right side.

First, the overall structure of the exhaust gas purifying apparatus will be described with reference to FIGS. As shown in FIGS. 1 to 5, a continuous regeneration type diesel particulate filter 1 (hereinafter referred to as a DPF) is provided as an exhaust gas purification device of the embodiment. The DPF 1 is for physically collecting particulate matter (PM) and the like in the exhaust gas. The DPF 1 exhausts a diesel oxidation catalyst 2 such as platinum that generates nitrogen dioxide (NO2) and a soot filter 3 having a honeycomb structure that continuously oxidizes and removes the collected particulate matter (PM) at a relatively low temperature. The gas is arranged in series in the gas movement direction (from left to right in FIG. 1). The DPF 1 is configured so that the soot filter 3 is continuously regenerated. The DPF 1 can reduce carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas in addition to the removal of particulate matter (PM) in the exhaust gas.

The attachment structure of the diesel oxidation catalyst 2 will be described with reference to FIGS. As shown in FIGS. 1 and 5, a diesel oxidation catalyst 2 as a gas purification filter for purifying exhaust gas discharged from an engine is installed in a substantially cylindrical catalyst inner case 4 made of a heat-resistant metal material. The catalyst inner case 4 is provided in a substantially cylindrical catalyst outer case 5 made of a heat-resistant metal material. That is, the catalyst inner case 4 is fitted on the outside of the diesel oxidation catalyst 2 via the mat-shaped ceramic fiber catalyst heat insulating material 6. Further, the catalyst outer case 5 is fitted on the outer side of the catalyst inner case 4 via a thin plate support 7 having an I-shaped end face. Note that the diesel oxidation catalyst 2 is protected by the catalyst heat insulating material 6. The stress (deformation force) of the catalyst outer case 5 transmitted to the catalyst inner case 4 is reduced by the thin plate support 7.

As shown in FIGS. 1 and 5, a disc-shaped left lid 8 is fixed to the left ends of the catalyst inner case 4 and the catalyst outer case 5 by welding. The left end face 2a of the diesel oxidation catalyst 2 and the left lid 8 are opposed to each other with a predetermined distance L1 for gas inflow space. An exhaust gas inflow space 11 is formed between the left end face 2 a of the diesel oxidation catalyst 2 and the left lid 8. A sensor connection plug 10 is fixed to a portion of the exhaust gas inflow space 11 in the catalyst inner case 4 and the catalyst outer case 5. An inlet side exhaust pressure sensor 10a as an exhaust pressure detecting means for detecting the pressure of the exhaust gas in the exhaust gas inflow space 11 is inserted and attached to the sensor connection plug 10.

As shown in FIGS. 1 and 5, a cylindrical exhaust gas inlet pipe 16 is inserted and fixed to the left end portions of the catalyst inner case 4 and the catalyst outer case 5 in which the exhaust gas inflow space 11 is formed. . Although not shown in detail, one end (tip) side of the exhaust gas inlet pipe 16 is closed. Between the catalyst inner case 4 and the catalyst outer case 5 in the exhaust gas inlet pipe 16, a closing ring body 15 is fixed in a sandwiched manner. A gap between the exhaust gas inlet pipe 16, the catalyst inner case 4, and the catalyst outer case 5 is closed by a closing ring body 15, and the closing ring body 15 connects the catalyst inner case 4 and the catalyst outer case 5. The exhaust gas is prevented from flowing in between.

A large number of opening holes 55 are formed in the exhaust gas inlet pipe 16 in the catalyst inner case 4. The inside of the exhaust gas inlet pipe 16 communicates with the inside of the catalyst inner case 4 through a large number of opening holes 55. Accordingly, the exhaust gas is sent from the exhaust gas inlet pipe 16 into the catalyst inner case 4 through the numerous opening holes 55. As shown in FIGS. 1, 3, and 5, an exhaust connection flange body 17 is welded to a protrusion of the exhaust gas inlet pipe 16 that protrudes from the catalyst outer case 5. The exhaust connection flange body 17 is connected to a relay exhaust pipe 85 connected to an exhaust manifold 71 of the diesel engine 70 via a bolt 18 (details will be described later).

With the above configuration, the exhaust gas of the diesel engine 70 enters the exhaust gas inlet pipe 16 from the exhaust manifold 71 and then is sent from the exhaust gas inlet pipe 16 to the exhaust gas inflow space 11 through the many opening holes 55. The diesel oxidation catalyst 2 is supplied from the left end face 2a side. Nitrogen dioxide (NO 2) is generated by the oxidation action of the diesel oxidation catalyst 2.

In the exhaust gas inflow space 11 on the exhaust gas inlet side of the DPF 1, an exhaust adjustment mechanism 54 for adjusting the amount of exhaust gas taken into the soot filter 3 as an example of a gas purification filter is disposed. The exhaust control mechanism 54 is for regenerating the soot filter 3 (recovering the particulate matter collecting ability). That is, when soot (particulate matter) is deposited on the soot filter 3, the engine load is increased by increasing the exhaust pressure of the diesel engine 70 by the action of the exhaust control mechanism 54. If it does so, the output (fuel injection amount) of the diesel engine 70 will increase in order to maintain the engine speed, and the exhaust gas temperature from the diesel engine 70 will rise. As a result, the soot deposited on the soot filter 3 burns and disappears, and the soot filter 3 is regenerated.

Therefore, in the diesel engine 70, for example, even if the engine load is low and the exhaust gas temperature is likely to be low (soot is likely to accumulate), the soot filter is forced by the exhaust control mechanism 54 to increase the exhaust pressure. 3 can be regenerated, and the exhaust gas purification performance of the DPF 1 can be properly maintained. A burner or heater for burning the soot deposited on the soot filter 3 is also unnecessary. Further, since the exhaust control mechanism 54 is incorporated in the configuration of the DPF 1, it is not necessary to attach the exhaust control mechanism 54 separately from the DPF 1, and the exhaust control mechanism 54 can be assembled only by attaching the DPF 1 to the diesel engine 70. It will be. For this reason, the types of exhaust system parts are reduced, and the assembly workability and maintenance workability of the exhaust system parts can be improved.

The exhaust control mechanism 54 of the embodiment includes a pipe cover body 56 provided on the outer peripheral side of the catalyst inner case 4 in the exhaust gas inlet pipe 16. The piping cover body 56 is for adjusting the open / closed state (number of openings) of the numerous opening holes 55 in the exhaust gas inlet pipe 16, and on the outer peripheral side in the catalyst inner case 4 in the exhaust gas inlet pipe 16. It is fitted so as to be slidable along its longitudinal direction. The pipe cover body 56 is linked to a cover actuator 58 attached to the outer surface side of the left lid body 8 via a transmission gear mechanism 57 such as a rack and pinion mechanism. By driving the cover actuator 58, the piping cover body 56 is slid along the longitudinal direction of the exhaust gas inlet pipe 16, and the number of the opening holes 55 blocked by the piping cover body 56 is changed. The flow rate of the exhaust gas sent from the pipe 16 into the catalyst inner case 4 and thus the flow resistance of the exhaust gas will fluctuate.

Further, a butterfly type on-off valve 59 which is another example of the exhaust control mechanism 54 is disposed in a portion of the exhaust gas inlet pipe 16 near the exhaust connection flange body 17. The butterfly type on-off valve is configured to open and close the exhaust gas inlet pipe 16 by driving a valve actuator 60 attached to the outer peripheral surface of the exhaust gas inlet pipe 16 protruding from the catalyst outer case 5. By adjusting the opening degree of the butterfly type on-off valve 59, the flow rate of the exhaust gas sent into the catalyst inner case 4 from the exhaust gas inlet pipe 16 and the flow resistance of the exhaust gas fluctuate similarly to the operation of the pipe cover body 56. Will do.

The mounting structure of the soot filter 3 will be described with reference to FIGS. As shown in FIGS. 1 and 5, the soot filter 3 as a gas purification filter for purifying exhaust gas discharged from the engine 70 is provided in a substantially cylindrical filter inner case 20 made of a heat-resistant metal material. The filter inner case 20 is provided in a substantially cylindrical filter outer case 21 made of a heat-resistant metal material. That is, the filter inner case 20 is fitted on the outside of the soot filter 3 via the mat-shaped ceramic fiber filter heat insulating material 22. The soot filter 3 is protected by the filter heat insulating material 22.

1 and 5, the catalyst side flange 25 is welded to the end of the catalyst outer case 5 on the downstream side (right side) of the exhaust gas movement. The filter-side flange 26 is welded to the middle of the filter inner case 20 in the exhaust gas movement direction and the end of the filter outer case 21 on the upstream side (left side) of the exhaust gas movement. The catalyst side flange 25 and the filter side flange 26 are detachably fastened by bolts 27 and nuts 28. The diameter of the cylindrical catalyst inner case 4 and the diameter of the cylindrical filter inner case 20 are substantially the same. Further, the diameter of the cylindrical catalyst outer case 5 and the diameter of the cylindrical filter outer case 21 are substantially the same.

As shown in FIG. 1, in a state where the filter outer case 21 is connected to the catalyst outer case 5 via the catalyst side flange 25 and the filter side flange 26, the exhaust gas movement downstream side (right side) end of the catalyst inner case 4 is shown. The end portion on the upstream side (left side) of the exhaust gas movement of the filter inner case 20 faces the portion spaced apart by a fixed interval L2 for sensor attachment. In other words, the sensor mounting space 29 is formed between the exhaust gas movement downstream side (right side) end of the catalyst inner case 4 and the exhaust gas movement upstream side (left side) end of the filter inner case 20. A sensor connection plug 50 is fixed to the catalyst outer case 5 at the sensor mounting space 29 position. For example, an inlet side exhaust gas temperature sensor (thermistor, not shown) is connected to the sensor connection plug 50.

As shown in FIG. 5, the cylindrical length L4 of the catalyst outer case 5 in the exhaust gas movement direction is longer than the cylindrical length L3 of the catalyst inner case 4 in the exhaust gas movement direction. The cylindrical length L6 of the filter outer case 21 in the exhaust gas movement direction is shorter than the cylindrical length L5 of the filter inner case 20 in the exhaust gas movement direction. A length (L2 + L3 + L5) obtained by adding the constant interval L2 of the sensor mounting space 29, the cylindrical length L3 of the catalyst inner case 4 and the cylindrical length L5 of the filter inner case 20 is the cylindrical length L4 of the catalyst outer case 5. And a length (L4 + L6) obtained by adding the cylindrical length L6 of the filter outer case 21 to be substantially equal to each other. The exhaust gas movement upstream side (left side) end of the filter outer case 21 is connected to the exhaust gas movement upstream side (left side) end of the filter inner case 20 by a difference in length (L7 = L5-L6). Protruding. That is, when the filter outer case 21 is connected to the catalyst outer case 5, the end of the filter inner case 20 on the upstream side (left side) of the exhaust gas movement is the overlap dimension L7, and the exhaust gas movement downstream side of the catalyst outer case 5 (Right side) is interpolated.

With the above configuration, nitrogen dioxide (NO2) generated by the oxidation action of the diesel oxidation catalyst 2 is supplied to the soot filter 3 from the left end face 3a. The collected particulate matter (PM) in the exhaust gas of the diesel engine 70 collected by the soot filter 3 is continuously oxidized and removed by nitrogen dioxide (NO2) at a relatively low temperature. In addition to the removal of particulate matter (PM) in the exhaust gas of the diesel engine 70, carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas of the diesel engine 70 are reduced.

As shown in FIGS. 1 to 5, a diesel oxidation catalyst 2 or soot filter 3 as a gas purification filter for purifying exhaust gas discharged from a diesel engine 70, and a catalyst inner case in which the diesel oxidation catalyst 2 or soot filter 3 is installed. 4, a filter inner case 20, a catalyst outer case 5 in which the catalyst inner case 4 and the filter inner case 20 are installed, and a filter outer case 21, a plurality of sets of diesel oxidation catalysts 2 and soot The filter 3, the catalyst inner case 4, the filter inner case 20, the catalyst outer case 5, and the filter outer case 21 are provided, and the catalyst outer case 5 and the filter outer case 21 with respect to the connection boundary position of the diesel oxidation catalyst 2 and the soot filter 3. Catalyst side flange 25 and fill as flange body connecting Since it is obtained by constituting the side flanges 26 so as to offset, by reducing the distance between the junction of the diesel oxidation catalyst 2 or the soot filter 3 can shorten the connection length of the catalyst outer case 5 and the filter outer case 21. Further, a gas sensor or the like can be easily arranged at the connection boundary position of the diesel oxidation catalyst 2 or the soot filter 3. Since the length of the catalyst outer case 5 and the filter outer case 21 in the exhaust gas movement direction can be shortened, the rigidity and weight of the catalyst outer case 5 and the filter outer case 21 can be improved.

As shown in FIGS. 1 to 5, two types of diesel oxidation catalysts 2 and soot filters 3 are provided, and a filter inner case 20 in which one soot filter 3 is installed is provided in the catalyst of the other diesel oxidation catalyst 2. Since the catalyst outer case 5 in which the inner case 4 is installed is configured to overlap, the catalyst outer case 5 or the soot filter 3 is secured while maintaining the length of the diesel oxidation catalyst 2 or the soot filter 3 in the exhaust gas movement direction. The length of the filter outer case 21 in the exhaust gas movement direction can be shortened. Further, since the catalyst inner case 4 (the other diesel oxidation catalyst 2) where the catalyst outer case 5 overlaps is largely exposed to the outside by the separation (disassembly) of the catalyst outer case 5 and the filter outer case 21, the catalyst inner case 4 is exposed. The exposure range of the case 4 (the other diesel oxidation catalyst 2) is increased, and maintenance work such as soot (particulate matter) removal of the one soot filter 3 can be easily performed.

As shown in FIGS. 1 to 5, a diesel oxidation catalyst 2 and a soot filter 3 are provided as a plurality of sets of gas purification filters, and the catalyst side flange 25 and the filter side flange 26 are offset on the outer peripheral side of the soot filter 3. Therefore, by separating the catalyst outer case 5 and the filter outer case 21, the end of the inner case 20 on the exhaust gas inlet side of the soot filter 5 can be greatly exposed from the end surface of the outer case 21. Maintenance work such as removal of soot adhering to the case 20 can be easily performed.

As shown in FIGS. 1 to 5, two types of diesel oxidation catalyst 2 and soot filter 3 are provided, and a catalyst inner case 4 in which one diesel oxidation catalyst 2 is installed, and the other soot filter 3 in the interior. Since the sensor mounting space 29 is formed between the filter inner case 20 and the filter outer case 20 to be provided, the connection length of the catalyst outer case 5 and the filter outer case 21 in the exhaust gas moving direction is shortened, and the catalyst outer case 5 is reduced. In addition, a gas sensor or the like can be easily arranged in the sensor mounting space 29 at the connection boundary position between the diesel oxidation catalyst 2 and the soot filter 3 while improving the rigidity and weight of the filter outer case 21 and the like.

As shown in FIGS. 1 to 5, a sensor connection plug 50 as a sensor support is assembled to the catalyst outer case 5 that overlaps the filter inner case 20, and the sensor is installed at the connection boundary position of the diesel oxidation catalyst 2 and the soot filter 3. Since the sensor means such as the inlet side exhaust gas temperature sensor (thermistor) is arranged via the connection plug 50, the catalyst outer case 5 and the filter outer case 21 are improved in rigidity and weight. The sensor connection plug 50 can be compactly installed at the connection boundary position of the diesel oxidation catalyst 2 and the soot filter 3 while being planned.

As described above, the diesel oxidation catalyst 2 and the soot filter 3 are provided as gas purification filters for purifying the exhaust gas discharged from the engine. However, instead of the diesel oxidation catalyst 2 and the soot filter 3, urea (reducing agent) is used. NOx selective reduction catalyst (NOx removal catalyst) for reducing nitrogen oxide (NOx) in the exhaust gas of the engine 70 by ammonia (NH3) generated by the addition of)) and residual ammonia discharged from the NOx selective reduction catalyst You may provide the ammonia removal catalyst to remove.

As described above, when a NOx selective reduction catalyst (NOx removal catalyst) is provided in the catalyst inner case 4 and an ammonia removal catalyst is provided in the filter inner case 20 as a gas purification filter, nitrogen oxidation in the exhaust gas exhausted by the engine is performed. The substance (NOx) is reduced and can be discharged as harmless nitrogen gas (N2).

1 to 5, the length of the catalyst inner case 4 and the filter inner case 20 in the exhaust gas moving direction is different from the length of the catalyst outer case 5 and the filter outer case 21 in the exhaust gas moving direction. Therefore, the flange body connecting the catalyst outer case 5 and the filter outer case 21 can be offset with respect to the joining position of the plurality of sets of the diesel oxidation catalyst 2 and the soot filter 3. The mounting interval of the plurality of sets of diesel oxidation catalysts 2 and soot filters 3 can be easily reduced or expanded.

As shown in FIGS. 1 to 5, a plurality of sets of diesel oxidation catalysts 2 and soot filters 3, a catalyst inner case 4 and a filter inner case 20, a catalyst outer case 5 and a filter outer case 21 are provided. The soot filter 3 is configured such that the catalyst side flange 25 and the filter side flange 26 connecting the plurality of sets of the catalyst outer case 5 and the filter outer case 21 are offset with respect to the joining position of the catalyst 2 and the soot filter 3. A catalyst outer case 5 facing the other diesel oxidation catalyst 2 is configured to overlap with the filter inner case 20 facing the other.

Therefore, a sensor or the like can be easily arranged between the junctions of the plurality of sets of diesel oxidation catalysts 2 and the soot filter 3 while the junction interval of the plurality of sets of diesel oxidation catalysts 2 and the soot filter 3 can be reduced. The lengths of the plurality of sets of catalyst outer cases 5 and filter outer cases 21 in the exhaust gas movement direction can be shortened to improve the rigidity and weight of the plurality of sets of catalyst outer cases 5 and filter outer cases 21 and the like. . By shortening the joining interval of the plurality of sets of diesel oxidation catalysts 2 and soot filters 3, the length of the plurality of sets of catalyst outer case 5 and filter outer case 21 in the exhaust gas moving direction can be shortened.

As shown in FIGS. 1 and 5, a drain plug 61 as a water draining mechanism that can communicate with the inside and the outside is provided in the vicinity of the sensor mounting space 29 on the outer peripheral surface of the catalyst outer case 5. The outward opening of the drain plug 61 is closed by a removable plug body 62. If comprised in this way, when the diesel engine 70 is not used for a long period of time, the inside of DPF1 can be maintained to the open air through the drain plug 60 only by removing the plug body 62. For this reason, it is possible to easily eliminate the accumulation of water in the DPF 1 due to condensation due to the long-term non-use of the diesel engine 70. For example, in the warm-up operation of the diesel engine 70, there is no need to evaporate water accumulated in the DPF 1. Further, since the generation of rust in the DPF 1 due to the presence of water can be reduced, the durability of the DPF 1 is also improved. In addition, the possibility of high temperature exhaust gas leaking out from the hole opened due to corrosion can be suppressed, and the possibility of peripheral equipment and the like being burned out by the high temperature exhaust gas can be extremely reduced.

The mounting structure of the silencer 30 will be described with reference to FIGS. 1 to 3 and FIGS. 5 to 7. As shown in FIGS. 1 to 3 and 5, the silencer 30 for attenuating the exhaust gas sound discharged from the diesel engine 70 includes a substantially cylindrical silencer inner case 31 made of a heat resistant metal material, and an abbreviation made of a heat resistant metal material. It has a cylindrical silencing outer case 32 and a disc-shaped right lid 33 fixed to the right end of the silencing inner case 31 and the silencing outer case 32 by welding. A silencer inner case 31 is provided in the silencer outer case 32. The diameter size of the cylindrical catalyst inner case 4, the diameter size of the cylindrical filter inner case 20, and the cylindrical sound deadening inner case 31 are substantially the same size. Further, the diameter of the cylindrical catalyst outer case 5, the diameter of the cylindrical filter outer case 21, and the cylindrical silencing outer case 32 are substantially the same.

As shown in FIGS. 4 to 7, an exhaust gas outlet pipe 34 is passed through the silencer inner case 31 and the silencer outer case 32. One end side of the exhaust gas outlet pipe 34 is closed by an outlet lid 35. A number of exhaust holes 36 are formed in the entire exhaust gas outlet pipe 34 inside the silencer inner case 31. The interior of the muffler inner case 31 is communicated with an exhaust gas outlet pipe 34 via a number of exhaust holes 36. A silencer and a tail pipe (not shown) are connected to the other end side of the exhaust gas outlet pipe 34.

As shown in FIGS. 6 and 7, the muffler inner case 31 has a large number of muffler holes 37. The interior of the silencer inner case 31 is communicated between the silencer inner case 31 and the silencer outer case 32 via a number of silencer holes 37. The space between the silencer inner case 31 and the silencer outer case 32 is closed by the right lid 33 and the thin plate support 38. A ceramic fiber silencer 39 is filled between the silencer inner case 31 and the silencer outer case 32. The exhaust gas movement upstream (left side) end of the muffler inner case 31 is connected to the exhaust gas movement upstream (left side) end of the muffler outer case 32 via a thin plate support 38.

With the above configuration, exhaust gas is discharged from the muffler inner case 31 through the exhaust gas outlet pipe 34. Further, in the silencer inner case 31, exhaust gas sounds (mainly high frequency band sounds) are absorbed into the silencer 39 from the numerous silencer holes 37. The noise of the exhaust gas discharged from the outlet side of the exhaust gas outlet pipe 34 is attenuated. In the embodiment, the casing of the DPF 1 is configured by the catalyst outer case 5, the filter outer case 21, the muffler outer case 32, and the left and right lid bodies 9 and 33.

As shown in FIGS. 1 and 5, the filter side outlet flange 40 is welded to the exhaust gas movement downstream side (right side) end of the filter inner case 20 and the filter outer case 21. The silencer flange 41 is welded to the exhaust gas movement upstream side (left side) of the silencer outer case 32. The filter side outlet flange 40 and the silencer side flange 41 are detachably fastened by bolts 42 and nuts 43. A sensor connection plug 44 is fixed to the filter inner case 20 and the filter outer case 21. The sensor connection plug 44 is fitted with an outlet side exhaust pressure sensor 44a as exhaust pressure detection means for detecting the pressure of the exhaust gas in the muffler inner case 31.

As shown in FIGS. 1, 2, 5 to 7, a diesel oxidation catalyst 2 or soot filter 3 as a gas purification filter for purifying exhaust gas discharged from the diesel engine 70, and a diesel oxidation catalyst 2 or soot filter 3 are provided. Exhaust gas comprising a catalyst inner case 4 or filter inner case 20 as an inner case to be installed inside, and a catalyst outer case 5 or filter outer case 21 as an outer case in which the catalyst inner case 4 or filter inner case 20 is installed. The gas purification apparatus includes a silencer 39 as an exhaust sound attenuator that attenuates the exhaust sound of the exhaust gas discharged from the diesel engine 70, and the silencer at the exhaust gas outlet side end of the catalyst outer case 5 or the filter outer case 21. 39 is arranged so that the diesel oxidation catalyst 2 or the soot filter 3 While maintaining the exhaust gas purification function, without changing the structure of the diesel oxidation catalyst 2 or the soot filter 3 can be easily added to mute the exhaust gas. For example, an exhaust structure in which a tail pipe is directly connected to the outer case, an exhaust structure that further improves the silencing function of an existing silencer, and the like can be easily configured. Further, it is possible to easily execute the high-frequency reduction measures for exhaust gas, which has been difficult to implement at the site of the diesel oxidation catalyst 2 or the soot filter 3. For example, a silencing structure (silencing material 39) formed by punch holes and a fibrous mat can be easily installed.

Since the silencer 30 having the silencer 39 is provided as shown in FIGS. 5 to 7 and the silencer 30 is detachably connected to the exhaust gas outlet side end of the filter outer case 21, By attaching / detaching the silencer 30, the exhaust gas silencing function in the diesel oxidation catalyst 2 or the soot filter 3 can be easily changed.

As shown in FIG. 5 to FIG. 7, a silencer 30 having a silencer 39 is provided, and the catalyst outer case 5 or the filter outer case 21 and the silencer 30 are formed in a cylindrical shape having substantially the same outer diameter, respectively. A filter-side outlet flange 40 as a ring-shaped flange body is provided at an end portion of the exhaust gas outlet side of 21, and a silencer 39 is attached to an end portion of the exhaust gas outlet side of the filter outer case 21 via the filter-side outlet flange 40. Since the silencer 30 having substantially the same outer diameter is connected to the filter outer case 21 by the filter-side outlet flange 40, the catalyst outer case is arranged in the exhaust gas moving direction. 5 or the filter outer case 21 can be assembled in a compact manner simply by lengthening the mounting dimension of the filter outer case 21. For example, the catalyst outer case 5 or the filter outer case 21 can be easily installed close to the side surface of the exhaust gas discharge part of the diesel engine 70. Moreover, the high frequency reduction measures of exhaust gas can be easily implemented by installing the silencer 39 while improving the gas purification function of the diesel oxidation catalyst 2 or the soot filter 3 by maintaining the temperature of the exhaust gas.

As shown in FIGS. 5 to 7, the silencer inner case 31 and the silencer outer case 32 as silencer casings in which the silencer 39 is incorporated, the one end side is closed, and the other end side is communicated with a tail pipe (not shown). An exhaust gas outlet pipe 34, and the silencer inner case 31 and the silencer outer case 32 are passed through the exhaust hole 36 forming portion of the exhaust gas outlet pipe 34, and the filter side outlet of the filter outer case 21 is connected to the filter side outlet. Since the silencer inner case 31 and the silencer outer case 32 are detachably connected via the flange 40, the diesel oxidation catalyst 2 or the soot filter can be removed by attaching and detaching the silencer inner case 31 and the silencer outer case 32. It is possible to easily change the exhaust gas silencing function in the third part. For example, by installing a silencer (not shown) separately from the silencer inner case 31 and the silencer outer case 32, an exhaust structure that further improves the exhaust gas silencer function can be easily configured. On the other hand, the exhaust structure in which the tail pipe (not shown) is directly connected to the filter outer case 21 can be easily configured by the arrangement of the silencer inner case 31 and the silencer outer case 32 in which the silencer 39 is not incorporated. Further, as a countermeasure for reducing the high frequency of exhaust gas, which has been difficult to implement at the site of the diesel oxidation catalyst 2 or the soot filter 3, a silencer 39 (punch hole and fibrous mat) is provided in the silencer inner case 31 and the silencer outer case 32. Etc.) The muffler structure can be easily configured.

As shown in FIGS. 5 to 7, the silencer casing has a cylindrical silencer inner case 31 and a cylindrical silencer outer case 32, and the silencer inner case 31 is arranged in the silencer outer case 32, and the silencer inner case is arranged. Since the silencer 39 is filled between the silencer 31 and the silencer outer case 32 and a number of silencer holes 37 are formed in the silencer inner case 31, the catalyst inner case 4 in which the diesel oxidation catalyst 2 or the soot filter 3 is installed. Alternatively, the silencer casing (the silencer inner case 31 and the silencer outer case 32) can be configured by approximating an exhaust gas purification structure including the filter inner case 20, the catalyst outer case 5, or the filter outer case 21. The silencer casing is silenced by using the same material (pipe or the like) as the catalyst inner case 4 or the filter inner case 20, the catalyst outer case 5 or the filter outer case 21 for installing the diesel oxidation catalyst 2 or the soot filter 3. The inner case 31 and the silencer outer case 32 can be formed. The manufacturing cost of the silencer casing can be easily reduced.

A structure in which the DPF 1 is provided in the diesel engine 70 will be described with reference to FIGS. As shown in FIGS. 8 to 10, an exhaust manifold 71 and an intake manifold 73 are arranged on the left and right side surfaces of the cylinder head 72 located at the upper part of the diesel engine 70. As is clear from FIG. 9, the exhaust manifold 71 and the intake manifold 73 are distributed on both sides of the cylinder head 72 in plan view. The cylinder head 72 is mounted on a cylinder block 75 having an engine output shaft 74 (crankshaft) and a piston (not shown). The front end and the rear end of the engine output shaft 74 are projected from the front and rear surfaces of the cylinder block 75. A cooling fan 76 for cooling the diesel engine 70 and the like is provided on the front surface of the cylinder block 75. The rotational force is transmitted from the front end side of the engine output shaft 74 to the cooling fan 76 via the V belt 77.

8 and 9, a flywheel housing 78 is fixed to the rear surface of the cylinder block 75. A flywheel 79 is installed in the flywheel housing 78. A flywheel 79 is pivotally supported on the rear end side of the engine output shaft 74. The power of the diesel engine 70 is extracted via a flywheel 79 to operating parts such as a backhoe 100 and a forklift car 120 described later. An oil pan 81 is arranged on the lower surface of the cylinder block 75. Engine leg mounting portions 82 are provided on the side surfaces of the cylinder block 75 and the flywheel housing 78. An engine leg 83 having anti-vibration rubber is fastened to the engine leg mounting portion 82 with bolts 80. The diesel engine 70 is supported in an anti-vibration manner via an engine leg 83 on an engine mounting chassis 84 such as a work vehicle (backhoe 100, forklift car 120).

8 and 10, one end side of a support leg 19 as a filter support is welded to the catalyst outer case 5 and the muffler outer case 32. The other end sides of the left and right support legs 19 are fastened with bolts 80 to a pair of left and right engine leg mounting portions 82 near the cooling fan 76 on the left and right side surfaces of the cylinder block 75. The above-described DPF 1 is supported by the highly rigid cylinder block 75 via the support leg 19. The DPF 1 is formed in a shape that is long in a direction orthogonal to the engine output shaft 74, and opposes the oil pan 81 below the cooling fan 76 so that the exhaust gas movement direction is orthogonal to the engine output shaft 74. (In front of the oil pan 81).

The exhaust gas inlet pipe 16 of the DPF 1 is detachably connected to the exhaust manifold 71 of the diesel engine 70 via a relay exhaust pipe 85. The exhaust gas moves from the exhaust manifold 71 of the diesel engine 70 into the DPF 1 through the relay exhaust pipe 85 and the exhaust gas inlet pipe 16, and the exhaust gas is purified by the DPF 1, and the tail pipe ( The exhaust gas moves to (not shown) and is finally discharged out of the machine. As shown in FIG. 11, the relay exhaust pipe 85 has a heat insulating structure. That is, the relay exhaust pipe 85 employs a double pipe structure, and a heat insulating material 88 made of, for example, ceramic fiber is filled between the inner pipe 86 and the outer pipe 87 covered therewith.

As is clear from the above configuration, a cooling fan 76 for cooling the diesel engine 70 is provided on one side of the diesel engine 70, and the exhaust gas from the diesel engine 70 is purified below the cooling fan 76. Therefore, the space below the cooling fan 76 is effectively used, and as close as possible to the exhaust manifold 71 of the diesel engine 70, and at a position where the cooling air from the cooling fan 76 is difficult to hit. Can be placed. Therefore, it is possible to suppress a decrease in the temperature of the DPF 1 due to the cooling air and the exhaust gas inside thereof, and it is easy to maintain the exhaust gas purification performance of the DPF 1 in an appropriate state. In addition, for example, the DPF 1 that is a heavy object from the silencer 30 or the like is disposed below the cooling fan 76, so that the center of gravity of the diesel engine 70 is lowered, and vibration isolation can be improved.

In addition, a pair of engine leg mounting portions 82 located near the cooling fan 76 on both the left and right side surfaces of the diesel engine 70 are provided with support legs 19 that support the DPF 1, and the DPF 1 includes the support legs 19. As a component of the diesel engine 70, the DPF 1 can be disposed with high rigidity on the diesel engine 70 as one of the components of the diesel engine 70. There is an effect that the versatility of the diesel engine 70 can be improved.

That is, the DPF 1 can be supported with high rigidity by using the high rigidity portion (cylinder block 75) of the diesel engine 70, and damage to the DPF 1 due to vibration or the like can be prevented. Further, it is possible to ship the DPF 1 incorporated in the diesel engine 70 at the manufacturing site of the diesel engine 70, and there is an advantage that the diesel engine 70 and the DPF 1 can be configured in a compact manner. As described above, since it is possible to ship the DPF 1 incorporated in the diesel engine 70, it is possible to omit the trouble of applying for shipment for each work vehicle on which the diesel engine 70 is mounted, and the manufacturing cost can be suppressed.

As shown in FIGS. 8 to 10, the DPF 1 according to the embodiment has a shape that is long in the left-right direction orthogonal to the engine output shaft 74, and is configured so that the exhaust gas moves in the DPF 1 along the left-right direction. Therefore, the DPF 1 can be extended in the left-right direction perpendicular to the engine output shaft 74 below the cooling fan 76. For this reason, it is possible to easily improve the exhaust gas purification performance and add a silencing function. Since the size of the DPF 1 in the direction of the engine output shaft 74 (front-rear direction) can be made compact, a space for arranging the DPF 1 can be easily secured below the cooling fan 76.

The DPF 1 of the embodiment is disposed below the cooling fan 76 so as to face the oil pan 81 (in front of the oil pan 81) so that the exhaust gas moving direction is a direction orthogonal to the engine output shaft 74. . For this reason, the upper surfaces of the cylinder head 72, the exhaust manifold 72, and the intake manifold 73 are exposed in a wide range, and maintenance work related to the diesel engine 70 is easy. Moreover, since the DPF 1 can be arranged as close to the diesel engine 70 as possible while avoiding the cooling air from the cooling fan 76 as close as possible to the exhaust manifold 71 of the diesel engine 70, the diesel engine incorporating the DPF 1 The engine 70 can be made compact.

As shown in FIGS. 8 to 10, a windshield 90 that blocks cooling air from the cooling fan 76 toward the DPF 1 is disposed between the DPF 1 and the cooling fan 76. The windshield 90 according to the embodiment has an arc plate shape curved along the DPF 1 casing (in this case, the catalyst outer case 5, the filter outer case 21, and the muffler outer case 32). It is attached to the housing side of the DPF 1 so as to cover the portion near 76. In this case, the windshield 90 is detachably fastened by bolts 92 to a plurality of mounting seats 91 welded and fixed to the outer peripheral surface of the housing in the DPF 1. As shown in detail in FIG. 9, a portion of the windshield 90 that overlaps with the exhaust gas inlet pipe 16 is cut out, and when the windshield 90 is attached to the DPF 1, the exhaust gas inlet pipe is formed in the cutout portion. 16 and an exhaust pipe windshield 93 (details will be described later) covering the same.

As described above, when the windshield 90 that blocks the cooling air from the cooling fan 76 toward the DPF 1 is disposed between the DPF 1 and the cooling fan 76, the cooling air from the cooling fan 76 can be prevented from directly hitting the DPF 1, It is possible to reliably suppress a decrease in the DPF 1 due to the wind, and consequently the exhaust gas temperature inside thereof. Therefore, the exhaust gas purification performance of the DPF 1 can be properly maintained.

Regarding the invention of the windshield 90, if the DPF 1 is disposed below the cooling fan 76 as in the embodiment, it is difficult for the cooling wind to hit only by the arrangement mode, and the exhaust gas generated by the cooling wind due to the presence of the windshield 90. It is preferable because a decrease in temperature can be reliably suppressed. However, the arrangement location of DPF1 should just be a peripheral part of diesel engine 70, and is not limited to the arrangement location (below cooling fan 76) of an embodiment.

In other words, if the windshield 90 is provided, there is no need to consider the adverse effect of the cooling air on the DPF 1, and therefore the location of the DPF 1 is rarely limited by the location of the cooling fan 76. This increases the degree of freedom of the layout of the DPF1.

Since the windshield 90 of the embodiment is attached to the chassis side of the DPF 1 so as to cover the portion of the DPF 1 near the cooling fan 76, the support structure of the windshield 90 is provided using the chassis of the DPF 1. Easy to configure. Further, since the windshield 90 can be incorporated in the configuration of the DPF 1, the workability of assembling exhaust system parts including the DPF 1 can be improved.

On the other hand, between the relay exhaust pipe 85 and the cooling fan 76, an exhaust pipe windshield 93 that blocks cooling air from the cooling fan 76 toward the relay exhaust pipe 85 is disposed. The exhaust pipe windshield 93 according to the embodiment is in the shape of an elongated plate having a circular cross section extending along the relay exhaust pipe 85, and relays so as to cover a portion near the cooling fan 76 on the outer peripheral surface of the relay exhaust pipe 85. It is attached to the exhaust pipe 85. In this case, the exhaust pipe windshield 93 is detachably fastened by bolts 95 to a plurality of mounting boss portions 94 welded and fixed to the outer peripheral surface of the outer pipe 87 in the relay exhaust pipe 85.

As described above, when the exhaust pipe wind shield 93 that blocks the cooling air from the cooling fan 76 toward the relay exhaust pipe 85 is disposed between the relay exhaust pipe 85 and the cooling fan 76, the relay exhaust pipe 85 is located in the vicinity of the cooling fan 76. Even if it passes through, it is possible to prevent the cooling air from the cooling fan 76 from directly hitting the relay exhaust pipe 85, and it is possible to reliably suppress a decrease in the exhaust gas temperature in the relay exhaust pipe 85 due to the cooling air. In addition, since the relay exhaust pipe 85 has a heat insulating structure, a decrease in the exhaust gas temperature in the relay exhaust pipe 85 due to cooling air is extremely suppressed. For this reason, it is not necessary to consider the adverse effect of the cooling air on the exhaust gas passing through the relay exhaust pipe 85, and the dead space below the cooling fan 76 can be effectively used as the arrangement space of the DPF 1.

Further, since the exhaust pipe windshield 93 of the embodiment is attached to the relay exhaust pipe 85 so as to cover a portion near the cooling fan 76 on the outer peripheral surface of the relay exhaust pipe 85, the relay exhaust pipe 85 (outside The support structure of the exhaust pipe windshield 93 can be easily configured using the outer peripheral surface of the pipe 87). Moreover, since the exhaust pipe windshield 93 can be incorporated into the configuration of the relay exhaust pipe 85, the workability of assembling exhaust system parts including the relay exhaust pipe 85 can be improved.

In addition, as shown in FIG.9 and FIG.10, the handle body 96 for carrying DPF1 is provided in the housing (in this case, the right side cover body 33) of DPF1 in embodiment. If comprised in this way, even if the housing of DPF1 is formed in the cylindrical shape which is hard to hold with one hand, DPF1 can be easily held with one hand using the handle body 96, and assembly and removal of DPF1 are easy. There is an advantage that can be done.

Next, a configuration for executing regeneration control of the soot filter 3 and an example of its control mode will be described with reference to FIGS. 12 and 13. A controller 140, which is an example of control means provided in a work vehicle (backhoe 100, forklift car 120) equipped with a diesel engine 70, stores a control program and data in addition to a CPU 141 that executes various arithmetic processes and controls. A ROM 142, a RAM 143 for temporarily storing control programs and data, an input / output interface, and the like are provided. Further, the controller 140 includes an inlet side exhaust pressure sensor 10a and an outlet side exhaust pressure sensor 44a as exhaust pressure detecting means, a cover actuator 58 for the piping cover body 56, a valve actuator 60 for the butterfly type on-off valve 59, and the like. Connected.

The controller 140 according to the embodiment increases the exhaust pressure of the diesel engine 70 by driving the exhaust control mechanism 54 (the piping cover body 56 and the butterfly on-off valve 59) based on the difference between the detection values of the

exhaust pressure sensors

10a and 44a. Thus, the soot filter 3 regeneration control for increasing the engine load is executed. The soot filter 3 regeneration control is executed at appropriate time intervals according to the result of the interrupt diagnosis process for checking the pressure difference ΔP between the upstream side and the downstream side of the DPF 1 with the soot filter 3 interposed therebetween.

In this case, as shown in the flowchart of FIG. 13, when the difference ΔP between the detection values of the

exhaust pressure sensors

10 a and 44 a is equal to or larger than a preset upper limit value ΔPmax, the exhaust actuator is driven by the cover actuator 58. 16, the pipe cover body 56 is slid in a direction to reduce the number of openings 55 in the opening hole 55, and the opening degree of the butterfly on-off valve 59 is narrowed by driving the valve actuator 60. Then, since the exhaust pressure of the diesel engine 70 increases and the engine load increases, the output (fuel injection amount) of the diesel engine 70 increases to maintain the engine speed, and the exhaust gas temperature from the diesel engine 70 increases. To rise. As a result, the soot deposited on the soot filter 3 burns and disappears, and the soot filter 3 is regenerated.

Thereafter, when the difference ΔP between the detection values of the

exhaust pressure sensors

10a, 44a becomes equal to or smaller than a preset lower limit value ΔPmin, the piping cover body 56 is returned to the original position before the numerical aperture is reduced by driving the cover actuator 58. And the opening degree of the butterfly type on-off valve 59 is returned to the original state before being narrowed by driving the valve actuator 60.

Note that it is not always necessary to use both the piping cover body 56 and the butterfly-type on-off valve 59 for the soot filter 3 regeneration control, and at least one of them may be used depending on the situation. The soot filter 3 regeneration control only needs to employ at least one of the configuration of the pipe cover body 56 and the butterfly type on-off valve 59. If both are used in combination, detailed soot filter 3 regeneration control considering the driving state of the diesel engine and the like becomes possible.

Referring to FIGS. 14 and 15, a structure in which the diesel engine 70 is mounted on the backhoe 100 will be described. As shown in FIGS. 14 and 15, the backhoe 100 includes a crawler-type traveling device 102 having a pair of left and right traveling crawlers 103, and a revolving machine body 104 provided on the traveling device 102. The revolving machine body 104 is configured to be horizontally revolved over 360 ° in all directions by a revolving hydraulic motor (not shown). An earthwork plate 105 for ground work is mounted on the rear part of the traveling device 102 so as to be movable up and down. A steering unit 106 and a diesel engine 70 are mounted on the left side of the revolving machine body 104. A working unit 110 having a boom 111 and a bucket 113 for excavation work is provided on the right side of the revolving machine body 104.

The control unit 106 is provided with a control seat 108 on which an operator is seated, an operation means for operating the diesel engine 70 and the like, and a lever or switch as an operation means for the working unit 110. A boom cylinder 112 and a bucket cylinder 114 are arranged on a boom 111 which is a component of the working unit 110. A bucket 113 as an attachment for excavation is pivotally attached to the tip end portion of the boom 111 so as to be inserted and rotated. The boom cylinder 112 or the bucket cylinder 114 is operated to perform earthwork work (ground work such as grooving) by the bucket 113.

A structure in which the diesel engine 70 is mounted on the forklift car 120 will be described with reference to FIGS. As shown in FIGS. 16 and 17, the forklift car 120 includes a traveling machine body 124 having a pair of left and right front wheels 122 and a rear wheel 123. The traveling body 124 is equipped with a control unit 125 and a diesel engine 70. The diesel engine 70 is covered from above with a cover body 133, and the control unit 125 is provided on the cover body 133.

A working part 127 having a fork 126 for cargo handling work is provided on the front side of the traveling machine body 124. A counterweight 131 is provided on the rear side of the traveling machine body 124 to balance the weight with the working unit 127. The control unit 125 is provided with a control seat 128 on which an operator is seated, a control handle 129, levers and switches as operation means for the diesel engine 70 and the working unit 127, and the like.

A fork 126 is mounted on the mast 130, which is a component of the working unit 127, so as to be movable up and down. The fork 126 is moved up and down, a pallet (not shown) loaded with a load is placed on the fork 126, the traveling machine body 124 is moved forward and backward, and a cargo handling operation such as transportation of the pallet is performed. Yes.

The diesel engine 70 is arranged such that the flywheel housing 78 is located on the front side of the traveling machine body 124 and the cooling fan 76 is located on the rear side of the traveling machine body 124. That is, the diesel engine 70 is arranged so that the direction of the engine output shaft 74 is along the front-rear direction in which the working unit 127 and the counterweight 131 are arranged. The diesel engine 70 is supported in an anti-vibration manner via an engine leg 83 on an engine mounting chassis 84 that constitutes the traveling machine body 124. A mission case 132 as an operating part is connected to the front side of the flywheel housing 78. The power from the diesel engine 70 via the flywheel 79 is appropriately changed in the transmission case 132 and transmitted to the hydraulic drive sources of the front wheels 122, the rear wheels 123, and the forks 126.

A radiator 134 for cooling the engine opposes the cooling fan 76 at a high position near the counterweight 131 between the control seat 128 and the counterweight 131 disposed behind the control seat 128 in the cover body 133. Are arranged as follows. By blowing cooling air to the radiator 134 by the rotation drive of the cooling fan 76, the radiator 134 is air-cooled.

As shown in FIG. 16, since the radiator 134 is disposed at a high position near the counterweight 131, a space is provided below the radiator 134 and the cooling fan 76. The DPF 1 is accommodated in the space so as to face the oil pan 81 arranged on the lower surface side of the diesel engine 70.

With this configuration, the space below the radiator 134 and the cooling fan 76 can be effectively used as the DPF 1 placement space, and the utilization efficiency of the internal space of the cover body 133 can be improved. Further, since the DPF 1 is disposed as close as possible to the exhaust manifold 71 of the diesel engine 70 and is difficult to receive the cooling air from the cooling fan 76, the DPF 1 due to the cooling air, and thus the exhaust gas temperature inside the DPF 1 is arranged. Can be suppressed, and the exhaust gas purification performance of the DPF 1 can be easily maintained in an appropriate state. In addition, for example, the DPF 1 that is a heavy object from the silencer 30 or the like is disposed below the cooling fan 76, so that the center of gravity of the diesel engine 70 is lowered and vibration isolation can be improved.

The configuration of each part in the present invention is not limited to the illustrated embodiment, and various modifications can be made without departing from the spirit of the present invention.

1 DPF (Exhaust Gas Purifier)
2 Diesel oxidation catalyst 3 Soot filter 16 Exhaust gas inlet pipe (DPF exhaust gas inlet)
19 Support leg (filter support)
34 Exhaust gas outlet pipe (DPF exhaust gas outlet)
54 Exhaust control mechanism 70 Diesel engine 71 Exhaust manifold 73 Intake manifold 76 Cooling fan 78 Flywheel housing 90 Windshield 120 Forklift car (work vehicle)
134 Radiator

Claims

An engine device mounted on a traveling machine body of a work vehicle,
On one side of the engine disposed below the control seat in the traveling machine body, it is equipped with a radiator for cooling the engine water, a cooling fan for cooling the engine and the radiator,
An exhaust gas purification device for purifying exhaust gas from the engine is disposed below the radiator and the cooling fan.
Engine equipment.
A filter support for supporting the exhaust gas purifying device is provided on a pair of engine leg mounting portions located near the cooling fan on both side surfaces of the engine, and the exhaust gas purifying device supports each filter. Connected to each engine leg mounting part through the body,
The engine device according to claim 1.
The exhaust gas purification device is disposed below the radiator and the cooling fan in a form that is long in a direction orthogonal to the output shaft of the engine, and exhaust gas is disposed in the exhaust gas purification device along the orthogonal direction. Configured to move,
The engine device according to claim 1.
The radiator and the cooling fan are disposed at a high position near the counterweight between the control seat and the counterweight disposed behind the control seat, and below the radiator and the cooling fan, and The exhaust gas purification device is disposed so as to face an oil pan disposed on the lower surface side of the engine.
The engine device according to claim 1.
Between the exhaust gas purification device and the cooling fan, a windshield that blocks cooling air from the cooling fan toward the exhaust gas purification device is disposed.
The engine device according to claim 2.
The windshield is attached to the housing of the exhaust gas purification device,
The engine device according to claim 5.
The exhaust manifold provided in the engine and the exhaust gas purification device are connected via a relay exhaust pipe, and the cooling fan is connected to the relay exhaust pipe between the relay exhaust pipe and the cooling fan. Exhaust pipe windshields that block the cooling air to go are arranged,
The engine device according to claim 5.
The exhaust manifold provided in the engine and the exhaust gas purification device are connected via a relay exhaust pipe, and the relay exhaust pipe has a heat insulating structure,
The engine device according to claim 5.