JP2019082152A - Vehicle, cargo handling vehicle, and exhaust gas treatment system - Google Patents

Abstract

To provide a vehicle, a cargo handling vehicle, and an exhaust gas treatment system, capable of compensating radiation loss of an exhaust gas flowing in an exhaust gas pipe, and preventing narrowing of an operation area to exert forcible regeneration function of a DPF.SOLUTION: A vehicle includes an engine, a vehicle main body having an engine room for housing the engine, an exhaust gas treatment device disposed outside of the engine room in the vehicle main body, and including a DPF capable of capturing PM in an exhaust gas discharged from the engine, and a first DOC disposed at an upstream side in a flowing direction of the exhaust gas with respect to the DPF, an exhaust gas pipe for supplying the exhaust gas discharged from the engine to a first DOC, and a heating device disposed in the exhaust pipe for heating the exhaust gas flowing in the exhaust gas pipe.SELECTED DRAWING: Figure 2

Description

  The present disclosure relates to a vehicle, a cargo handling vehicle, and an exhaust gas treatment system provided with an exhaust gas treatment device for treating an exhaust gas discharged from an engine.

  BACKGROUND ART In order to process exhaust gas discharged from an engine such as a diesel engine, an exhaust gas processing device may be installed in an exhaust gas pipe through which the exhaust gas flows. In the exhaust gas processing apparatus, DOC (oxidation catalyst device, diesel oxidation catalyst) for oxidizing and removing carbon monoxide (CO), hydrocarbons (HC) and the like contained in the exhaust gas, and the flow direction of the exhaust gas from the DOC There are DPFs (particulate collection filter device, diesel particulate filter) disposed downstream to collect and remove PM (particulate matter) in exhaust gas (for example, Patent Documents 1 to 3).

  If the PM collected in the DPF is accumulated and the DPF is clogged, the PM collection capacity may be reduced or the exhaust pressure may be increased, which may lead to deterioration of fuel efficiency. In order to solve this problem, some exhaust gas processing apparatuses have a DPF forced regeneration function that burns and removes PM accumulated in the DPF using high temperature exhaust gas discharged from the engine (for example, Patent documents 1 and 2).

  In Patent Document 1, the above-described DPF forced regeneration function exerts a function by forcibly raising the inlet temperature of the DPF, and the forced temperature increase of the inlet temperature of the DPF is generally main It is described that unburned fuel is supplied to the DOC by post injection which injects the fuel later than the combustion injection timing, and the unburned fuel is oxidized and generated by the DOC.

  In Patent Document 2, a second oxidation catalyst device (second DOC) is connected in series upstream of the first oxidation catalyst device (first DOC), and the flow path of exhaust gas is switched upstream of the second oxidation catalyst device. It is described to provide a channel switching valve for the purpose. Then, according to Patent Document 2, when the temperature of the exhaust gas does not reach the reference temperature due to the light load operation of the engine, the flow path of the exhaust gas is increased by the flow path switching valve to substantially expand the capacity of the oxidation catalyst device. It is described that the exhaust gas flows to the first oxidation catalyst device after passing through the second oxidation catalyst device.

  Patent Document 3 describes that, in an industrial vehicle having a cargo handling device on the front side of the vehicle and having a counterweight on the rear side of the vehicle, disposing the DPF inside an engine room for housing the engine. ing. The industrial vehicle described in Patent Document 3 can shorten the exhaust gas pipe for flowing the exhaust gas between the engine and the DPF by arranging the DPF inside the engine room, and the temperature decrease of the exhaust gas in the exhaust gas pipe Can be suppressed.

JP, 2015-68233, A JP, 2010-236363, A JP, 2014-162296, A

  However, the inventions described in Patent Documents 1 to 3 do not compensate for the heat radiation loss of the exhaust gas when flowing through the exhaust gas pipe for supplying the exhaust gas discharged from the engine to the DOC. That is, the invention described in Patent Document 1 is not an invention in which the problem of compensating for the heat radiation loss of the exhaust gas flowing through the above-described exhaust gas pipe is made. In the invention described in Patent Document 2, the exhaust gas pipe is configured to be short in order to suppress the heat radiation loss of the exhaust gas in consideration of the fact that the heat radiation loss of the exhaust gas is increased correspondingly when the exhaust gas pipe is long. . For example, the first oxidation catalyst device and the second oxidation catalyst device may be directly butted and connected, or the flow path switching valve, the first oxidation catalyst device, the second oxidation catalyst device, and the DPF may be disposed near the engine. It is The invention described in Patent Document 3 has a configuration in which the exhaust gas pipe is short in order to suppress the heat radiation loss of the exhaust gas. Thus, the inventions described in Patent Documents 2 and 3 are inventions for shortening the length of the exhaust gas pipe, and do not eliminate the temperature decrease due to the heat radiation of the exhaust gas when flowing through the exhaust gas pipe.

  Therefore, in the inventions described in Patent Documents 1 to 3, even if the temperature of the exhaust gas discharged from the engine is adjusted so that the oxidation catalyst included in the DOC is activated, The operating range where DPF regeneration function can not be performed is such that the temperature of the exhaust gas supplied to the DOC falls below the activation temperature of the oxidation catalyst included in the DOC due to the temperature decrease due to the heat release of the exhaust gas when flowing through the exhaust gas pipe. There is a risk of becoming wider. In other words, there is a possibility that the operating range in which the regeneration function of the DPF can be exhibited becomes narrow.

  In the inventions described in Patent Documents 2 and 3, as described above, since it is necessary to shorten the length of the exhaust gas pipe, there is a problem that the layout of DOC and DPF is lacking. The invention described in Patent Document 2 requires arranging the first oxidation catalyst device, the second oxidation catalyst device, and the DPF along the engine, and the invention described in Patent Document 3 accommodates the engine. Although it is necessary to arrange the DPF inside the engine room, for example, some vehicles of cargo handling vehicles (forklifts etc.) do not have enough space inside the engine room and DOC or DPF inside the engine room There is a possibility that it can not be arranged.

  In view of the above-described circumstances, the object of at least one embodiment of the present invention is to compensate for the heat radiation loss of the exhaust gas flowing through the exhaust gas pipe, and to prevent the narrowing of the operating region capable of exhibiting the forced regeneration function of the DPF. It is providing a vehicle, a cargo handling vehicle, and an exhaust gas treatment system.

(1) A vehicle according to at least one embodiment of the present invention,
With the engine,
A vehicle body having an engine room for housing the engine;
An exhaust gas processing device disposed outside the engine room in the vehicle body, the DPF capable of collecting PM in exhaust gas discharged from the engine, and an upstream side of the DPF in the flow direction of the exhaust gas An exhaust gas treatment device including a first DOC disposed in
An exhaust gas pipe for flowing the exhaust gas discharged from the engine to the first DOC;
And at least one heating device provided in the exhaust gas pipe for heating the exhaust gas flowing through the exhaust gas pipe.

  According to the configuration of (1), the vehicle accommodates the engine inside the engine room of the vehicle body, and the exhaust gas processing device including the first DOC and the DPF is installed outside the engine room of the vehicle body. Then, the vehicle includes an exhaust gas pipe for flowing the exhaust gas discharged from the engine to the first DOC of the exhaust gas processing device, and at least one heating device provided in the exhaust gas pipe for heating the exhaust gas flowing in the exhaust gas pipe Have.

  Since the exhaust gas treatment device is disposed outside the engine room, the exhaust gas pipe becomes longer and the heat radiation loss of the exhaust gas when flowing through the exhaust gas pipe becomes greater than when the exhaust gas treatment device is disposed inside the engine room. For this reason, there is a possibility that the operating region in which the forced regeneration function of the DPF can not be exhibited can be broadened such that the temperature of the exhaust gas supplied to the first DOC becomes less than the activation temperature of the oxidation catalyst included in the first DOC. In other words, there is a possibility that the operating range in which the forced regeneration function of the DPF can be exhibited becomes narrow. However, by heating the exhaust gas flowing through the exhaust gas pipe by the heating device, the vehicle can compensate for the heat radiation loss of the exhaust gas when flowing through the above-described exhaust gas pipe, and the operating range where the forced regeneration function of the DPF can be exhibited is narrow. Can be prevented.

  Moreover, since the vehicle provided with such a heating device can lengthen the length of the exhaust gas pipe without degrading the function of the exhaust gas processing device, the layout of the exhaust gas processing device in the vehicle can be improved. In addition, since the exhaust gas processing device is disposed outside the engine room housing the engine, it is possible to reduce the wear and damage of the first DOC and the DPF due to the vibration of the engine.

(2) In some embodiments, in the configuration of (1) above,
The at least one heating device comprises a plurality of heating devices.
According to the configuration of (2), since the at least one heating device includes the plurality of heating devices, the exhaust gas flowing through the exhaust gas pipe can be heated stepwise by the plurality of heating devices. Since heating of the exhaust gas can be shared by a plurality of heating devices, each heating device may be a small one with low heating performance. For this reason, the enlargement of each heating device can be prevented, and the layout of the plurality of heating devices in the vehicle main body can be improved. Moreover, since it is not necessary to make exhaust gas high temperature with one heating apparatus, deterioration by the heat of a heating apparatus can be suppressed.

(3) In some embodiments, in the configuration of (1) or (2) above,
The at least one heating device includes at least one second DOC disposed inside the engine compartment.

  According to the configuration of (3), since the heating device includes at least one second DOC disposed inside the engine room, fuel is injected into the combustion chamber at a timing not contributing to combustion in the engine (late post By injecting the unburned fuel into the second DOC, the exhaust gas flowing through the exhaust gas pipe can be heated by the second DOC. The exhaust gas flowing through the exhaust pipe inside the engine room, which is located upstream in the flow direction of the exhaust gas, has a small temperature drop due to heat radiation, and can activate the oxidation catalyst included in the second DOC. Therefore, the second DOC can heat the exhaust gas passing through the second DOC by the heat generated by the oxidation reaction of the exhaust gas by the oxidation catalyst by adding the necessary unburned fuel (late post injection), It is possible to compensate for the heat radiation loss when flowing through the exhaust gas pipe.

  In particular, when the heating device includes a plurality of second DOCs disposed inside the engine room, the exhaust gas whose flow is disrupted at the inlet of each second DOC flows to the second DOC, so the reaction of the exhaust gas as a whole of the second DOC Can be enhanced.

(4) In some embodiments, in the configuration of (3) above,
And a controller for controlling the engine.
The control device includes a post injection control unit that controls execution of post injection for supplying unburned fuel to the first DOC and the second DOC,
At the time of forced regeneration of the DPF, the post injection control unit
A first step of raising the temperature of the second DOC to the activation temperature by raising the temperature of the exhaust gas at the outlet of the engine by injecting fuel into the combustion chamber of the engine;
After the first step, a second step of raising the first DOC to an activation temperature by supplying a predetermined amount of unburned fuel to the second DOC, and after the second step, the second DOC is sent to the first DOC. A third step of forced regeneration of the DPF by supplying more unburned fuel than the predetermined amount;
Configured to perform.

  According to the configuration of the above (4), the post injection control unit of the control device is configured to execute the first step, the second step and the third step at the time of forced regeneration of the DPF. Therefore, after raising the second DOC to the activation temperature in the first step, the oxidation reaction in the second DOC and the first DOC can be efficiently performed by raising the first DOC to the activation temperature in the second step. In addition, after raising the first DOC to the activation temperature in the second step, more unburned fuel is supplied than the unburned fuel supplied to the second DOC in the second step to the first DOC in the third step By doing this, it is possible to raise the temperature of the exhaust gas at the outlet of the first DOC and the inlet of the DPF by the oxidation reaction in the first DOC while suppressing adhesion of unburned fuel to the exhaust gas pipe and the like. For this reason, forced regeneration by DPF can be performed efficiently.

(5) In some embodiments, in the configuration of (3) or (4) above,
The amount of precious metal catalyst contained in the second DOC is 1/50 or more and 1/5 or less of the amount of precious metal catalyst contained in the first DOC.

  According to the configuration of the above (5), since the first DOC and the second DOC contain the precious metal catalyst, the engine is in a low load operation, and the exhaust gas emitted from the engine is contained in the exhaust gas even if the temperature is low. It is possible to oxidize and remove hydrocarbons (HC) and the like. Further, since the amount of precious metal catalyst contained in the second DOC is 1/50 or more of the amount of precious metal catalyst contained in the first DOC, the temperature at which the exhaust gas supplied to the first DOC can activate the oxidation catalyst included in the first DOC Thus, the exhaust gas can be heated by the second DOC. In addition, since the amount of precious metal catalyst contained in the second DOC is 1⁄5 or less of the amount of precious metal catalyst contained in the first DOC, the heat generation due to the oxidation reaction in the second DOC is suppressed and the exhaust gas becomes too high temperature in the second DOC. It can be prevented. Here, the condition that the amount of precious metal catalyst contained in the second DOC is 1/50 or more and 1/5 or less of the amount of precious metal catalyst contained in the first DOC is derived as a result of intensive studies by the present inventors. If the condition is not satisfied, there is the following possibility. That is, if the temperature of the exhaust gas in the second DOC becomes too high, the catalyst of the second DOC may be degraded by heat. In addition, it is necessary to further increase the amount of injection of unburned fuel (the amount of injection of late post injection) by the increase of the amount of heat release from the exhaust gas pipe, which may lead to the deterioration of fuel efficiency. For this reason, the second DOC that satisfies the above-described conditions can suppress catalyst deterioration due to heat and suppress deterioration of the combustion efficiency of the engine.

(6) In some embodiments, in the above configurations (3) to (5),
When the external dimension in the direction orthogonal to the axis of the first DOC is D0, the external dimension D in the direction orthogonal to the axis of the second DOC satisfies D ≦ D0.
According to the configuration of the above (6), when the external dimension in the direction orthogonal to the axis of the first DOC is D0, the external dimension D in the direction orthogonal to the axis of the second DOC satisfies D ≦ D0. It is possible to improve the layout of the exhaust pipe in which the 2DOC and the second DOC are provided in the engine room.

(7) In some embodiments, in the configurations of (1) to (6) above,
A controller for controlling the engine;
A second exhaust gas temperature detection device that detects the temperature of the exhaust gas supplied to the first DOC;
The controller is
According to the detection result of a said 2nd exhaust gas temperature detection apparatus, the calorie | heat amount control part which controls the calorie | heat amount added to the said waste gas by the said at least 1 heating device is included.

  According to the configuration of (7), the heat amount control unit of the control device controls the amount of heat added to the exhaust gas by the heating device according to the detection result of the second exhaust gas temperature detection device. Therefore, the heating device can heat the exhaust gas so that the second exhaust gas temperature detection device detects a predetermined temperature, for example, a temperature at which the first DOC has activity.

(8) In some embodiments, in the configurations of (1) to (6) above,
A controller for controlling the engine;
A first exhaust gas temperature detection device for detecting the temperature of the exhaust gas discharged from the engine;
A second exhaust gas temperature detection device that detects the temperature of the exhaust gas supplied to the first DOC;
The controller is
According to the detection result of a said 1st exhaust gas temperature detection apparatus and a said 2nd exhaust gas temperature detection apparatus, the calorie | heat amount control part which controls the calorie | heat amount added to the said exhaust gas by the said at least 1 heating device is included.

  According to the configuration of (8), a first exhaust gas temperature detection device for detecting the temperature of exhaust gas discharged from the engine, and a second exhaust gas temperature detection device for detecting the temperature of the exhaust gas supplied to the first DOC Since the control device is provided, the temperature calculated by the heat release in the exhaust gas pipe is calculated from the difference between the temperature of the exhaust gas detected by the first exhaust gas temperature detection device and the temperature of the exhaust gas detected by the second exhaust gas temperature detection device Can. Then, the heat quantity control unit of the control device controls the amount of heat added to the exhaust gas by the heating device according to the detection results of the first exhaust gas temperature detection device and the second exhaust gas temperature detection device, thereby the first exhaust gas temperature detection device The exhaust gas can be heated by the heating device such that the difference between the temperature of the exhaust gas detected in the above and the temperature of the exhaust gas detected by the second exhaust gas temperature detection device disappears.

(9) A cargo handling vehicle according to at least one embodiment of the present invention,
A cargo handling vehicle including a vehicle having the configuration of (1) to (8) above,
The cargo handling vehicle is
A cargo handling device provided in front of the engine room;
And a counterweight provided rearward of the engine room to limit movement of the center of gravity of the cargo handling vehicle.
The exhaust gas treatment device is disposed in an internal space defined by the counterweight.

  According to the configuration of the above (9), the cargo handling vehicle is provided with the cargo handling device provided in front of the engine room, and the counterweight provided behind the engine compartment in order to restrict the movement of the center of gravity of the cargo handling vehicle. So I can not enlarge the engine room. Therefore, there is a possibility that the exhaust gas processing device can not be installed inside the engine room. Therefore, by disposing the exhaust gas processing device not in the engine room but in the internal space defined by the counterweights, it is possible to improve the layout particularly in the engine room of the cargo handling vehicle.

  In addition, since the exhaust gas treatment device is disposed in the internal space defined by the counterweight, the exhaust gas pipe becomes longer than in the case where the exhaust gas treatment device is disposed inside the engine room, and the heat radiation of the exhaust gas when flowing through the exhaust gas pipe The loss will increase. However, since the cargo handling vehicle equipped with the heating device can lengthen the length of the exhaust gas pipe without reducing the function of the exhaust gas processing device, it improves the layout in the internal space defined by the counterweight of the exhaust gas processing device. It can be done. Moreover, since the exhaust gas processing device is disposed not in the engine room but in the above-described internal space, it is possible to reduce the wear and damage of the first DOC and the DPF due to the vibration of the engine.

(10) In some embodiments, in the configuration of (9) above,
The cargo handling vehicle further includes a radiator which is disposed between an internal space defined by the counterweight and the engine room, and which divides the internal space from the engine room.
According to the configuration of the above (10), since the cargo handling vehicle is divided by the radiator into the internal space defined by the counterweight and the engine room, the radiator is not installed in the aforementioned internal space or other places in the engine compartment Therefore, the layout of the internal space and the engine room described above can be improved.

(11) An exhaust gas treatment system according to at least one embodiment of the present invention,
An exhaust gas processing apparatus for treating exhaust gas discharged from an engine, comprising: a DPF capable of collecting PM in the exhaust gas; and a first DOC disposed upstream of the DPF in the flow direction of the exhaust gas An exhaust gas treatment device,
An exhaust gas pipe for flowing the exhaust gas discharged from the engine to the first DOC;
And a heating device provided in the exhaust gas pipe and heating the exhaust gas flowing through the exhaust gas pipe in order to compensate the heat radiation loss of the exhaust gas flowing through the exhaust gas pipe.

  According to the configuration of the above (11), the exhaust gas treatment system is an exhaust gas treatment device for treating the exhaust gas discharged from the engine, and the exhaust gas treatment device containing the first DOC and the DPF, and the exhaust gas discharged from the engine And a heating device provided in the exhaust gas pipe and heating the exhaust gas flowing in the exhaust gas pipe to compensate for the heat radiation loss of the exhaust gas flowing in the exhaust gas pipe. . In such an exhaust gas treatment system, when the exhaust gas pipe is long, the heat radiation loss of the exhaust gas when flowing through the exhaust gas pipe becomes large. For this reason, there is a possibility that the operating region in which the forced regeneration function of the DPF can not be exhibited can be expanded such that the temperature of the exhaust gas supplied to the first DOC becomes less than the activation temperature of the oxidation catalyst included in the first DOC. In other words, there is a possibility that the operating range in which the forced regeneration function of the DPF can be exhibited becomes narrow. However, by heating the exhaust gas flowing through the exhaust gas pipe by the heating device, the exhaust gas processing system can compensate the heat radiation loss of the exhaust gas when flowing through the above-described exhaust gas pipe, and can operate the forced regeneration function of the DPF. Can be prevented from becoming narrow.

  According to at least one embodiment of the present invention, a vehicle, a cargo handling vehicle, and an exhaust gas that can compensate for the heat radiation loss of the exhaust gas flowing through the exhaust gas pipe and can prevent the narrowing of the operating region capable of exerting the forced regeneration function of the DPF. A processing system is provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure for demonstrating the vehicle concerning one Embodiment of this invention, Comprising: It is a schematic side view which shows schematically the whole structure of a forklift as an example of a vehicle. It is a schematic block diagram for demonstrating the exhaust gas processing system concerning one embodiment of the present invention. It is a figure for explaining a control device in an exhaust gas treatment system concerning one embodiment of the present invention, and is a schematic structure figure showing an exhaust gas treatment system containing a control device. It is a schematic block diagram for demonstrating the exhaust gas processing system concerning other one Embodiment of this invention, Comprising: It is a figure for demonstrating the exhaust gas processing system provided with a several heating apparatus and a heat insulation apparatus. It is a figure for demonstrating the arrangement seen from the upper part of the engine and exhaust gas processing device in the forklift shown in FIG. 1, and is a schematic cross section showing the main components inside the internal space defined by the engine room and the counterweight. It is. It is a figure for demonstrating fixation of the heating apparatus shown in FIG. 5, Comprising: It is the schematic which shows the main components of the heating apparatus vicinity when the inside of an engine room is seen from the side. It is a block diagram for demonstrating the function of the control apparatus shown in FIG. It is a flow figure showing an example of injection control of fuel by a control device.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative arrangements, etc. of the components described as the embodiments or shown in the drawings are not intended to limit the scope of the present invention to this, but are merely illustrative. Absent.
For example, a representation representing a relative or absolute arrangement such as “in a direction”, “along a direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” is strictly Not only does it represent such an arrangement, but also represents a state of relative displacement with an angle or distance that allows the same function to be obtained.
For example, expressions that indicate that things such as "identical", "equal" and "homogeneous" are equal states not only represent strictly equal states, but also have tolerances or differences with which the same function can be obtained. It also represents the existing state.
For example, expressions representing shapes such as quadrilateral shapes and cylindrical shapes not only represent shapes such as rectangular shapes and cylindrical shapes in a geometrically strict sense, but also uneven portions and chamfers within the range where the same effect can be obtained. The shape including a part etc. shall also be expressed.
On the other hand, the expressions "comprising", "having", "having", "including" or "having" one component are not exclusive expressions excluding the presence of other components.

  FIG. 1 is a view for explaining a vehicle according to an embodiment of the present invention, and is a schematic side view schematically showing an entire configuration of a forklift as an example of the vehicle. As shown in FIG. 1, a vehicle 1 according to some embodiments includes an engine 3 including a diesel engine or the like as a power source for driving the vehicle 1 and an engine room 21 housing the engine 3. A main body 2 is provided. Hereinafter, in the embodiment according to FIGS. 1 to 8, the forklift 10 </ b> A (the cargo handling vehicle 10) will be described as an example of the vehicle 1.

  In the forklift 10A (the cargo handling vehicle 10), as shown in FIG. 1, an engine room 21 is provided below a seat on which a passenger sits, and the engine 3 is housed inside the engine room 21. Here, the engine 3 at least has a combustion chamber 311 defined by a cylinder head and a cylinder block. The engine room 21 is a space capable of storing the above-described engine 3 and is a space partitioned by a part of the vehicle body 2 or a space partitioned by a part of the vehicle body 2 and other members. In the embodiment shown in FIG. 1, the engine room 21 is a space defined by an upper wall portion 211, a front wall portion 212, side walls 213 and 214, a bottom portion 215 and the like which are parts of the vehicle body 2. The side wall 214 is provided on the opposite side to the side wall 213 shown in FIG.

  As shown in FIG. 1, the forklift 10A (the cargo handling vehicle 10) includes a cargo handling device 11 such as a fork provided in front of the engine room 21 in the vehicle body 2 and a counter provided behind the engine room 21 in the vehicle body 2 And a weight 12. The counterweight 12 restricts the movement of the center of gravity of the cargo handling device 11 and the forklift 10A when placing and transporting a load on the cargo handling device 11, and plays a role of a weight to stabilize the behavior of the forklift 10A.

  The forklift 10A has an internal space 120 defined by the counterweight 12, as shown in FIG. Here, the internal space 120 defined by the counterweight 12 refers to a space partitioned by a part of the counterweight 12 or a space partitioned by a part of the counterweight 12 and another member. The embodiment shown in FIG. 1 is a space defined by the counterweight 12 and the upper wall 121, which is a part of the vehicle body 2, the rear wall 122, the side walls 123 and 124, the bottom 125, and the like. The side wall portion 124 is provided on the opposite side to the side wall portion 123 shown in FIG.

  As shown in FIG. 1, the forklift 10 </ b> A includes an exhaust gas processing device 5 disposed in an internal space 120 defined by the counterweight 12, which is outside the engine room 21 of the vehicle body 2.

  FIG. 2 is a schematic configuration view for explaining an exhaust gas treatment system according to an embodiment of the present invention. FIG. 3 is a view for explaining the control device in the exhaust gas processing system according to one embodiment of the present invention, and is a schematic configuration view showing the exhaust gas processing system including the control device. FIG. 4 is a schematic configuration view for explaining an exhaust gas treatment system according to another embodiment of the present invention, and is a view for explaining an exhaust gas treatment system provided with a plurality of heating devices and a heat insulating device. . FIG. 5 is a view for explaining the arrangement viewed from above of the engine and the exhaust gas processing device in the forklift shown in FIG. 1, and shows the main components inside the internal space defined by the engine room and the counterweight. It is a schematic sectional view shown. FIG. 6 is a view for explaining fixation of the heating device shown in FIG. 5, and is a schematic view showing main components in the vicinity of the heating device when the inside of the engine room is viewed from the side.

  As shown in FIGS. 2 to 5, the exhaust gas processing device 5 is for processing the exhaust gas discharged from the engine 3, and is disposed downstream of the engine 3 in the flow direction of the exhaust gas. As shown in FIGS. 2 to 5, the exhaust gas processing device 5 is capable of collecting PM (particulate matter) such as soot contained in the exhaust gas discharged from the engine 3. And a first DOC 51 (an oxidation catalyst device, a diesel oxidation catalyst) disposed upstream of the DPF 52 in the flow direction of the exhaust gas.

  As shown in FIG. 3, an intake pipe 25 is connected to the upstream side of the engine 3 via an intake manifold 26. As shown in FIGS. 2 to 5, an exhaust gas pipe 6 is connected to the downstream side of the engine 3 in the flow direction of the exhaust gas. The exhaust gas pipe 6 is connected to the upstream side of the first DOC 51 of the exhaust gas processing device 5 so that the exhaust gas discharged from the engine 3 flows to the first DOC 51.

  In the embodiment shown in FIG. 3, a turbocharger 35 is provided between the intake pipe 25 and the exhaust pipe 6. The turbocharger 35 has an exhaust turbine 351 disposed in the exhaust pipe 6, and a compressor 352 disposed in the intake pipe 25. The exhaust turbine 351 and the compressor 352 are coaxially driven. There is. The intake pipe 25 is provided with an intake throttle valve 27 whose opening degree is controlled by the control device 8. The compressed air supercharged by the compressor 352 flows into the combustion chamber 311 of the engine 3 after the flow rate is controlled by the intake throttle valve 27. In the embodiment shown in FIG. 3, although the flow rate is controlled by both the intake throttle valve 27 and the exhaust throttle valve 34 described later, the flow rate is controlled by only either the intake throttle valve 27 or the exhaust throttle valve 34. It may be controlled. Further, in some other embodiments, the turbocharger 35 may be omitted.

  As shown in FIG. 3, the engine 3 is provided with a fuel injection valve 28 for injecting unburned fuel into the combustion chamber 311. The injection timing of the unburned fuel and the unburned fuel injection amount of the fuel injection valve 28 are controlled by the control device 8. The unburned fuel injected into the combustion chamber 311 at the time of main injection is mixed with the above-described compressed air, and then burns in the combustion chamber 311.

  The exhaust gas discharged from the engine 3 drives the exhaust turbine 351 described above. The exhaust gas that has driven the exhaust turbine 351 described above is controlled by the exhaust throttle valve 34 whose opening degree is controlled by the control device 8 as shown in FIGS. Flow into The exhaust throttle valve 34 may be provided on the upstream side of the turbocharger 35 in the flow direction of the exhaust gas, or may be provided on the downstream side of the turbocharger 35.

The first DOC 51 of the exhaust gas processing apparatus 5 described above has a main body made of ceramic, metal or the like formed by forming a large number of honeycomb-shaped air holes and having a cylindrical or rectangular outer shape and an inner surface of the main body. And a supported oxidation catalyst 511. The first DOC 51 promotes the oxidation reaction with the oxidation catalyst 511, thereby oxidizing and removing unburned fuel (HC) and carbon monoxide (CO) in the exhaust gas passing through the first DOC 51, and NO) has a function of producing nitrogen dioxide (NO ₂ ) capable of burning and removing PM by reaction with PM trapped in the DPF 52 by oxidation. Further, the first DOC 51 raises the temperature of the exhaust gas passing through the first DOC 51 by the heat generated by the oxidation reaction of the unburned fuel contained in the exhaust gas, and raises the inlet temperature of the DPF 52.

  The DPF 52 of the exhaust gas processing device 5 has a large number of air holes in a honeycomb shape, and is configured by forming the outer shape into a cylindrical shape or a rectangular solid shape. The DPF 52 is configured such that adjacent ones of the plurality of vent holes are alternately closed on the inlet side and the outlet side so that the exhaust gas passes through the filtration wall (filter). For this reason, when exhaust gas passes the filtration wall of DPF52, PM is removed. The DPF 52 may support an oxidation catalyst on its inner surface.

  Further, as shown in FIGS. 2 to 5, an exhaust gas pipe 53 is connected to the downstream side of the first DOC 51 in the flow direction of the exhaust gas. The exhaust gas pipe 53 is connected to the upstream side of the DPF 52, and the exhaust gas heated by the heat generated by the oxidation reaction in the first DOC 51 flows to the DPF 52.

  As shown in FIGS. 2 to 5, an exhaust gas discharge pipe 54 (muffler) is connected to the downstream side of the DPF 52 in the flow direction of the exhaust gas. The exhaust gas discharge pipe 54 is provided with an outlet opening 541 outside the internal space 120 of the counterweight 12. Therefore, the exhaust gas is removed from the exhaust gas discharge pipe 54 after unburned fuel (HC) and carbon monoxide (CO) contained in the exhaust gas are removed in the first DOC 51 and PM contained in the exhaust gas is removed in the DPF 52. It is discharged to the outside of the vehicle body 2 from the outlet opening 541.

  The PM removed by the DPF 52 is partially burned (continuous regeneration) by the high temperature exhaust gas discharged from the engine 3 during operation (continuous regeneration), but the remaining is accumulated on the filter wall of the DPF 52. For this reason, the exhaust gas processing device 5 including the DPF 52 is required to exert a forced regeneration function of forcibly burning PM accumulated in the filtration wall of the DPF 52 to regenerate the filtration wall. Here, the forced regeneration function is an automatic regeneration function automatically implemented by the control device 8 by satisfying a predetermined forced regeneration execution condition, and a manual regeneration function implemented by a manual operation of the operator of the forklift 10A or the like. Contains. When the estimated value of the deposition amount of PM accumulated on the filtration wall of the DPF 52 exceeds the specified value, the operation time of the engine 3 exceeds the specified time, and the fuel injection of the engine 3 is performed under predetermined forced regeneration execution conditions. There are cases where the cumulative value of the amount exceeds the specified value.

  As shown in FIG. 3, a second DOC inlet temperature sensor 41 that detects the inlet temperature of the second DOC 71 and an inlet temperature of the first DOC 51 are detected in the exhaust gas pipe 6 as the temperature of the exhaust gas discharged from the engine 3. A 1 DOC inlet temperature sensor 42 is disposed. The exhaust gas pipe 53 is provided with a DPF inlet temperature sensor 43 for detecting the inlet temperature of the DPF 52. The exhaust gas discharge pipe 54 is provided with a DPF outlet temperature sensor 44 that detects the outlet temperature of the DPF 52. In the DPF 52, a DPF inlet pressure sensor 45, a DPF outlet pressure sensor 46, and a DPF differential pressure sensor 47 are disposed. Signals relating to the inlet temperature of the second DOC 71, the inlet temperature of the first DOC 51, the inlet temperature of the DPF 52, the outlet temperature of the DPF 52, the differential pressure of the DPF 52, etc. measured by these sensors are input to the control device 8. .

  The control device 8 is for controlling the engine 3 and is configured as a microcomputer including a central processing unit (CPU), a random access memory (RAM), a read only memory (ROM), an I / O interface, and the like. Ru. Further, the control device 8 can perform control based on the signals measured by the above-described sensors.

  FIG. 7 is a block diagram for explaining the function of the control device shown in FIG. FIG. 8 is a flow chart showing an example of fuel injection control by the control device. As shown in FIG. 7, the control device 8 includes an injection control unit 80 that controls the execution of the injection. As shown in FIG. 7, the injection control unit 80 includes a main injection control unit 81 that controls the execution of the main injection, and a post injection control unit 82 that controls the execution of the post injection. Here, the post injection, as shown in FIG. 8, is the injection of fuel (steps S20 and S30) by the fuel injection valve 28 which is performed later than the main injection (step S10). In the embodiment shown in FIG. 8, the post injection performs early post injection (step S20) for injecting fuel into the combustion chamber 311 at a timing that contributes to the combustion in the engine 3 and combustion at a timing that does not contribute to the combustion in the engine 3 And late post injection (step S30) for injecting fuel into the chamber 311. In late post injection, the temperature of the exhaust gas at the outlet of the engine 3 is raised by fuel injection into the combustion chamber 311 of the engine 3, or unburned fuel is supplied to the first DOC 51 of the exhaust gas processing device 5. It will be. However, in some other embodiments, post injection may not include early post injection. Hereinafter, post injection means late post injection unless otherwise stated.

  The main injection control unit 81 is configured to be able to control the injection timing of the unburned fuel and the injection amount of the unburned fuel ejected from the fuel injection valve 28 (see FIG. 3) during the main injection. The post injection control unit 82 is configured to be able to control the injection timing of the unburned fuel and the injection amount of the unburned fuel ejected from the fuel injection valve 28 at the time of post injection including early post injection and late post injection. Further, even if the main injection control unit 81 and the post injection control unit 82 are configured to be able to control the opening degree of the intake throttle valve 27 (see FIG. 3) and the exhaust throttle valve 34 (see FIGS. 2 and 5 to 7). Alternatively, the flow rate of the compressed air supplied to the engine 3 and the flow rate of the exhaust gas discharged from the engine 3 may be controlled.

  At the time of forced regeneration of the DPF 52, the unburned fuel flowing into the first DOC 51 is oxidized and heat-generated in the first DOC 51 by post injection of the fuel injection valve 28, thereby forcibly raising the inlet temperature of the DPF 52 and forcibly forcing PM. It is supposed to burn. Alternatively, unburned fuel may be injected from the exhaust gas pipe injection valve 29 (see FIG. 3) disposed in the exhaust gas pipe 6 instead of or in combination with post injection of the fuel injection valve 28. In this case, as shown in FIG. 7, the above-described injection control unit 80 may include an exhaust gas pipe injection control unit 83 that controls the execution of the injection of unburned fuel by the exhaust gas pipe injection valve 29. The exhaust gas pipe injection control unit 83 is configured to be able to control the injection timing of the unburned fuel ejected from the exhaust gas pipe injection valve 29 and the injection amount of the unburned fuel.

  As shown in FIGS. 1, 2, 4 and 5, the exhaust gas processing device 5 is disposed outside the engine room 21, and therefore, the exhaust gas pipe 6 is compared to the case where it is disposed inside the engine room 21. Becomes long, and the heat radiation loss of the exhaust gas when flowing through the exhaust gas pipe 6 becomes large. The forklift 10A is configured to be able to compensate for the heat radiation loss of the exhaust gas when flowing through the exhaust gas pipe 6. That is, as shown in FIGS. 2 to 5, the forklift 10 </ b> A is provided in the middle of the exhaust gas pipe 6 described above, and includes at least one heating device 7 for heating the exhaust gas flowing through the exhaust gas pipe 6.

  In the embodiment shown in FIGS. 2 to 5, the heating device 7 comprises a second DOC 71 arranged inside the engine compartment 21. The second DOC 71 has the same configuration as the first DOC 51 of the exhaust gas processing device 5 described above. That is, the second DOC 71 includes a main body made of a ceramic, metal or the like formed by forming a honeycomb shape into a cylindrical shape or a rectangular solid shape in which a large number of fine holes penetrate, and an oxidation catalyst 711 supported on the inner surface of the main body. It contains.

Then, the second DOC 71 of the heating device 7 promotes the oxidation reaction by the oxidation catalyst 711 to raise the temperature of the exhaust gas passing through the second DOC 71 by the heat generated by the oxidation reaction of the unburned fuel contained in the exhaust gas. The outlet temperature of the 2DOC 71 and the inlet temperature of the first DOC 51 are increased. During forced regeneration of the DPF 52, the outlet temperature of the second DOC 71 and the inlet temperature of the first DOC 51 are forcedly raised by causing the second DOC 71 to oxidize and generate unburned fuel that has flowed into the second DOC 71 by post injection of the fuel injection valve 28 It is supposed to be. The second DOC 71 promotes the oxidation reaction with the oxidation catalyst 711 to oxidize and remove the unburned fuel (HC) and carbon monoxide (CO) in the exhaust gas passing through the second DOC 71, as well as the oxidation of one part in the exhaust gas. It has a function of oxidizing nitrogen (NO) and generating nitrogen dioxide (NO ₂ ) capable of burning and removing PM by reaction with PM collected in the DPF 52.

  As described above, the vehicle 1 according to some embodiments includes the engine 3 described above, the vehicle main body 2 having the engine room 21 described above, the exhaust gas processing device 5 including the first DOC 51 and the DPF 52 described above, An exhaust gas pipe 6 and the above-described heating device 7 are provided.

  According to the above configuration, the vehicle 1 houses the engine 3 inside the engine room 21 of the vehicle body 2, and the exhaust gas processing device 5 is installed outside the engine room 21 of the vehicle body 2. The exhaust gas processing device 5 includes a DPF 52 capable of collecting PM in exhaust gas discharged from the engine 3 and a first DOC 51 disposed upstream of the DPF 52 in the flow direction of the exhaust gas. Then, the vehicle 1 is provided in the exhaust gas pipe 6 for supplying the exhaust gas discharged from the engine 3 to the first DOC 51 of the exhaust gas processing device 5 and the exhaust gas pipe 6 and at least for heating the exhaust gas flowing through the exhaust gas pipe 6 One heating device 7 is provided.

  Since the exhaust gas processing device 5 is disposed outside the engine room 21, the exhaust gas pipe 6 becomes longer than in the case where the exhaust gas processing device 5 is disposed inside the engine room 21, and heat radiation of exhaust gas when flowing through the exhaust gas pipe 6 The loss will increase. For this reason, there is a possibility that the operating region in which the forced regeneration function of the DPF 52 can not be exhibited can be broadened such that the temperature of the exhaust gas supplied to the first DOC 51 becomes less than the activation temperature of the oxidation catalyst 511 included in the first DOC 51. In other words, there is a possibility that the operating range in which the forced regeneration function of the DPF 52 can be exhibited becomes narrow. However, by heating the exhaust gas flowing through the exhaust gas pipe 6 with the heating device 7, the vehicle 1 can compensate for the heat radiation loss of the exhaust gas when flowing through the exhaust gas pipe 6 described above, and can exert the forced regeneration function of the DPF 52 It is possible to prevent the operating range from becoming narrow.

  Moreover, since the vehicle 1 equipped with such a heating device 7 can lengthen the length of the exhaust gas pipe 6 without reducing the function of the exhaust gas processing device 5, the layout of the exhaust gas processing device 5 in the vehicle 1 can be improved. It can be improved. Further, since the exhaust gas processing device 5 is disposed outside the engine room 21 housing the engine 3, it is possible to reduce the wear and damage of the first DOC 51 and the DPF 52 due to the vibration of the engine 3.

  In some embodiments, as shown in FIG. 4, the at least one heating device 7 described above includes a plurality of heating devices 7 (heating devices 7A, 7B). In this case, the exhaust gas flowing through the exhaust gas pipe 6 can be heated stepwise by the plurality of heating devices 7. Since heating of the exhaust gas can be shared by the plurality of heating devices 7, each heating device 7 may be a small one with low heating performance. For this reason, the enlargement of each heating device 7 can be prevented, and the layout property of the plurality of heating devices 7 in the vehicle main body 2 can be improved. Moreover, since it is not necessary to make exhaust gas high temperature with one heating device 7, degradation by the heat of heating device 7 can be controlled.

  In some embodiments, as shown in FIGS. 2-5, the above-described heating device 7 includes at least one of the above-described second DOCs 71 disposed inside the engine compartment 21. In this case, the fuel is injected into the combustion chamber 311 (late post injection) at a timing that does not contribute to the combustion in the engine 3 and the unburned fuel is supplied to the second DOC 71. Can be heated. The exhaust gas flowing through the exhaust gas pipe 6 inside the engine room 21 located on the upstream side in the flow direction of the exhaust gas has a small temperature drop due to heat radiation, and can activate the oxidation catalyst 711 included in the second DOC 71. Therefore, the second DOC 71 can heat the exhaust gas passing through the second DOC 71 by the heat generated by the oxidation reaction of the exhaust gas by the oxidation catalyst 711 by adding necessary unburned fuel (late post injection), The heat radiation loss of the exhaust gas when flowing through the pipe 6 can be compensated.

  In particular, as shown in FIG. 4, when the heating device 7 includes a plurality of second DOCs 71 (second DOCs 71 A and 71 B) disposed inside the engine room 21, the flow is disturbed at the inlet of each of the second DOCs 71. Since the exhaust gas flows to the second DOC 71, the reactivity of the exhaust gas can be enhanced as a whole of the second DOC 71. In addition, since 2nd DOC71A and 71B have the structure similar to 2nd DOC71 mentioned above, it omits about a concrete structure.

  In some embodiments, the above-described vehicle 1 further includes the above-described control device 8 including the above-described post injection control unit 82. The post injection control unit 82 described above is configured to be able to control execution of post injection for supplying unburned fuel to the first DOC 51 and the second DOC 71 described above. Then, as shown in FIG. 8, the post injection control unit 82 performs the first step S301, the second step S302, and the third step S303 at the time of forced regeneration of the DPF 52, that is, at the time of post injection (step S30). It is configured to run.

  In the first step S301, the temperature of the exhaust gas at the outlet of the engine 3 is raised by fuel injection into the combustion chamber 311 of the engine 3 to raise the second DOC to the activation temperature. In the second step S302, the first DOC 51 is raised to the activation temperature by supplying a predetermined amount of unburned fuel to the second DOC 71 after the first step S301. In the third step S303, after the second step S302, forced regeneration of the DPF 52 is performed by supplying more unburned fuel to the first DOC 51 than the predetermined amount of the second step S302. As an example, the activation temperature of 1st DOC51 and 2nd DOC71 is 250-260 degreeC, and the inlet temperature of DPF52 at the time of forced regeneration is 600-610 degreeC.

  According to the above configuration, the post injection control unit 82 of the control device 8 is configured to execute the first step S301, the second step S302, and the third step S303 during forced regeneration of the DPF 52. Therefore, after the second DOC 71 is raised to the activation temperature in the first step S301, the oxidation reaction in the second DOC 71 and the first DOC 51 can be efficiently performed by raising the first DOC 51 to the activation temperature in the second step S302. it can. Moreover, after raising 1st DOC51 to activation temperature by 2nd step S302, there are more unburned fuels than unburned fuel supplied with respect to 1st DOC51 with 3rd step S303 with respect to 2nd DOC71 in 2nd step S302. By supplying fuel, the exhaust gas temperature at the outlet of the first DOC 51 and the inlet of the DPF 52 can be raised by the oxidation reaction in the first DOC 51 while suppressing adhesion of unburned fuel to the exhaust gas pipe 6 and the like. Therefore, forced regeneration by the DPF 52 can be efficiently performed.

  In some embodiments, the precious metal catalyst amount contained in the second DOC 71 described above is 1/50 or more and 1/5 or less of the precious metal catalyst amount contained in the first DOC 51 described above. Examples of noble metal catalysts include platinum, palladium and rhodium. In this case, since the first DOC 51 and the second DOC 71 contain a noble metal catalyst, the engine 3 is in a low load operation, and hydrocarbons contained in the exhaust gas are discharged even if the exhaust gas discharged from the engine 3 has a low temperature ( HC) etc. can be oxidized and removed.

  Further, since the amount of precious metal catalyst contained in the second DOC 71 is 1/50 or more of the amount of precious metal catalyst contained in the first DOC 51, the temperature at which exhaust gas supplied to the first DOC 51 can activate the oxidation catalyst included in the first DOC 51 The exhaust gas can be heated by the second DOC 71 so that Further, since the amount of precious metal catalyst contained in the second DOC 71 is 1⁄5 or less of the amount of precious metal catalyst contained in the first DOC 51, the heat generation due to the oxidation reaction in the second DOC 71 is suppressed and the exhaust gas becomes too high temperature in the second DOC 71 It can be prevented. Here, the condition that the amount of precious metal catalyst contained in the second DOC 71 is 1/50 or more and 1/5 or less of the amount of precious metal catalyst contained in the first DOC 51 is derived as a result of intensive studies by the inventors. If the condition is not satisfied, there is the following possibility. That is, if the temperature of the exhaust gas in the second DOC 71 becomes too high, the catalyst of the second DOC 71 may be deteriorated by heat. Further, it is necessary to further increase the amount of injection of unburned fuel (the amount of injection of late post injection) by the increase of the amount of heat release from the exhaust gas pipe 6, and there is a possibility that the fuel efficiency will be deteriorated. Therefore, the second DOC 71 that satisfies the above-described conditions can suppress catalyst deterioration due to heat and suppress deterioration of the combustion efficiency of the engine 3.

  In some embodiments, as shown in FIG. 4, assuming that the external dimension in the direction orthogonal to the axis of the first DOC 51 is D0, the external dimension D in the direction orthogonal to the axis of the second DOC 71 described above is It is designed to satisfy D ≦ D0. In this case, assuming that the external dimension in the direction orthogonal to the axis of the first DOC 51 is D0, the external diameter D in the direction orthogonal to the axis of the second DOC 71 satisfies D ≦ D0, so the second DOC 71 and the second DOC 71 The layout of the provided exhaust gas pipe 6 in the engine room 21 can be improved.

  In some embodiments, as shown in FIG. 3, the vehicle 1 described above includes the first DOC inlet temperature sensor 42 (second exhaust gas temperature detection device) described above that detects the temperature of the exhaust gas supplied to the first DOC 51. It is equipped further. As shown in FIG. 7, the control device 8 described above includes a heat amount control unit 84A that controls the amount of heat added to the exhaust gas by the heating device 7 in accordance with the detection result of the first DOC inlet temperature sensor 42. In this case, the heat amount control unit 84A of the control device 8 controls the amount of heat added to the exhaust gas by the heating device 7 in accordance with the detection result of the first DOC inlet temperature sensor 42. Therefore, the exhaust gas can be heated by the heating device 7 so that the first DOC inlet temperature sensor 42 detects a predetermined temperature, for example, a temperature at which the first DOC 51 has activity.

  In some embodiments, as shown in FIG. 3, the vehicle 1 described above not only includes the first DOC inlet temperature sensor 42 described above, but also detects the temperature of the exhaust gas discharged from the engine 3 described above A 2DOC inlet temperature sensor 41 (first exhaust gas temperature detection device) is further provided. As shown in FIG. 7, the control device 8 described above controls the heat amount control unit that controls the amount of heat added to the exhaust gas by the heating device 7 according to the detection results of the second DOC inlet temperature sensor 41 and the first DOC inlet temperature sensor 42. Contains 84B.

  According to the above configuration, the controller 8 detects the temperature of the second DOC inlet temperature sensor 41 (first exhaust gas temperature detection device) for detecting the temperature of the exhaust gas discharged from the engine 3 and the temperature of the exhaust gas supplied to the first DOC 51 From the difference between the temperature of the exhaust gas detected by the first DOC inlet temperature sensor 42 (the second exhaust gas temperature detecting device) to be detected, the temperature lowered by the heat radiation in the exhaust gas pipe 6 can be calculated. Then, the heat amount control unit 84B of the control device 8 controls the amount of heat applied to the exhaust gas by the heating device 7 in accordance with the detection results of the second DOC inlet temperature sensor 41 and the first DOC inlet temperature sensor 42, thereby the second DOC inlet The exhaust gas can be heated by the heating device 7 so that the difference between the temperature of the exhaust gas detected by the temperature sensor 41 and the temperature of the exhaust gas detected by the first DOC inlet temperature sensor 42 disappears.

  The cargo handling vehicle 10 according to some embodiments includes the configuration of the vehicle 1 according to some embodiments described above. That is, as illustrated in FIGS. 2 to 5, the cargo handling vehicle 10 includes the above-described engine 3, the vehicle body 2 having the above-described engine room 21, the exhaust gas processing device 5 including the above-described first DOC 51 and the DPF 52, and At least the exhaust gas pipe 6 and the heating device 7 described above are provided. And, as shown in FIG. 1, the cargo handling vehicle 10 has a cargo handling device 11 provided in front of the engine room 21 and a counter weight 12 provided behind the engine compartment 21 to restrict the movement of the center of gravity of the cargo handling vehicle 10. And further. The exhaust gas processing device 5 is disposed in an internal space 120 defined by the counterweight 12.

  According to the above configuration, the cargo handling vehicle 10 includes the cargo handling device 11 provided in front of the engine room 21 and the counterweight 12 provided behind the engine compartment 21 to limit the movement of the center of gravity of the cargo handling vehicle 10. Since it is equipped, the engine room 21 can not be enlarged. Therefore, there is a possibility that the exhaust gas processing device 5 can not be installed inside the engine room 21. Therefore, by disposing the exhaust gas processing device 5 not in the engine room 21 but in the internal space 120 defined by the counterweight 12, the layout property of the inside of the engine room 21 in the cargo handling vehicle 10 can be improved.

  Further, since the exhaust gas processing device 5 is disposed in the internal space 120 defined by the counterweight 12, the exhaust gas pipe 6 is longer than in the case where the exhaust gas processing device 5 is disposed inside the engine room 21. The heat radiation loss of the exhaust gas at the time of flowing becomes large. However, since the cargo handling vehicle 10 provided with the heating device 7 can lengthen the length of the exhaust gas pipe 6 without degrading the function of the exhaust gas processing device 5, the inside defined by the counterweight 12 of the exhaust gas processing device 5 The layout in the space 120 can be improved. Further, since the exhaust gas processing device 5 is disposed not in the engine room 21 but in the internal space 120 defined by the counterweight 12, wear and damage of the first DOC 51 and the DPF 52 due to the vibration of the engine 3 can be reduced. .

  In some embodiments, as shown in FIG. 5, the above-described cargo handling vehicle 10 is disposed between the interior space 120 defined by the counterweight 12 and the engine compartment 21 to provide the interior space 120 with the engine compartment 21 further includes a radiator 36 that separates the two. As shown in FIG. 5, engine room 21 is arranged to extend in the front-rear direction of vehicle body 2 in the front-rear direction orthogonal to front wall 212, side wall 213, side wall 214, bottom 215 and vehicle body 2. It is defined by the radiator 36 etc. Further, as shown in FIG. 5, the internal space 120 of the counterweight 12 is defined by the rear wall 122, the side wall 123, the side wall 124 of the counterweight 12, the bottom 215 of the vehicle main body 2, the radiator 36 described above, etc. It is done.

  In the embodiment shown in FIGS. 5 and 6, the engine 3 disposed in the engine room 21 includes an engine body 31, an alternator 32 mounted on the engine body 31 and rotated by the engine body 31, and an engine body And includes an engine bracket 33 that supports the portion 31 and is installed on the bottom portion 215. Then, as shown in FIGS. 5 and 6, the exhaust throttle valve 34 and the turbocharger 35 are fixed to the engine body 31.

  The first DOC 51 and the DPF 52 of the exhaust gas processing device 5 disposed in the internal space 120 of the counterweight 12 are combined with the oil cooler 37 by the support bracket 22 and the support bracket 23 erected on the bottom portion 215 as shown in FIG. It is supported. The first DOC 51 is disposed below the DPF 52 in order to shorten the exhaust gas pipe 6. The exhaust gas processing device 5 is disposed on the opposite side to the radiator 36 with the oil cooler 37 interposed therebetween, and is mounted on the engine 3 by the exhaust gas pipe 6 piped in one direction in the extension direction of the radiator 36 (vertical direction in FIG. 5). It is connected. A precleaner 38 and an air cleaner 39 are installed on the other side in the extension direction of the radiator 36. The precleaner 38 is installed in the internal space 120, and the air cleaner 39 is installed in the engine room 21. As shown in FIG. 6, the second DOC 71 is fixed to the engine bracket 33 by a bolt or the like while being mounted on the engine bracket 33.

  According to the above configuration, since the cargo handling vehicle 10 divides the internal space 120 of the counterweight 12 and the engine room 21 by the radiator 36, the radiator 36 is not installed in the internal space 120 or any other place in the engine room 21. Therefore, the layout of the internal space 120 and the engine room 21 can be improved.

  As shown in FIGS. 2 to 5, the exhaust gas processing system 4 according to some embodiments includes the exhaust gas processing device 5 including the first DOC 51 and the DPF 52 described above, the exhaust gas pipe 6 described above, and the exhaust gas flowing through the exhaust gas pipe 6. And the above-mentioned heating device 7 for heating the exhaust gas flowing through the exhaust gas pipe 6 in order to compensate for the heat radiation loss of the above.

  According to the above configuration, as shown in FIGS. 2 to 5, the exhaust gas treatment system 4 is an exhaust gas treatment device 5 for treating the exhaust gas discharged from the engine 3 and includes the first DOC 51 and the DPF 52. The exhaust gas pipe 6 for supplying the processing device 5 and the exhaust gas discharged from the engine 3 to the first DOC 51 of the exhaust gas processing device 5 and the exhaust gas pipe 6 are provided to compensate for the heat radiation loss of the exhaust gas flowing through the exhaust gas pipe 6 And a heating device 7 for heating the exhaust gas flowing through the exhaust gas pipe 6. In such an exhaust gas treatment system 4, when the exhaust gas pipe 6 is long, the heat radiation loss of the exhaust gas when flowing through the exhaust gas pipe 6 becomes large by that amount. For this reason, there is a possibility that the operation region in which the forced regeneration function of the DPF 52 can not be exhibited can be broadened such that the temperature of the exhaust gas supplied to the first DOC 51 becomes lower than the activation temperature of the oxidation catalyst 511 included in the first DOC 51. In other words, there is a possibility that the operating range in which the forced regeneration function of the DPF 52 can be exhibited becomes narrow. However, the exhaust gas processing system 4 can compensate the heat radiation loss of the exhaust gas when flowing through the above-described exhaust gas pipe 6 by heating the exhaust gas flowing through the exhaust gas pipe 6 by the heating device 7. It is possible to prevent the narrowing of the operating range that can be exhibited.

  In some embodiments, as shown in FIGS. 2, 4 and 5, the exhaust pipe 6 is provided with a bellows 61. In the embodiment shown in FIGS. 2 and 4, it is provided upstream of the heating device 7 in the flow direction of the exhaust gas. In the embodiment shown in FIG. 5, it is provided on the downstream side of the heating device 7 in the flow direction of the exhaust gas and on the upstream side of the exhaust gas treatment device 5. In these cases, the bellows 61 suppresses the transmission of the vibration generated by the driving of the engine 3 to the downstream side of the exhaust gas flow direction of the exhaust gas pipe 6 rather than the bellows 61, and the exhaust gas more than the bellows 61. A device such as the first DOC 51 or DPF 52 located downstream of the pipe 6 in the flow direction of the exhaust gas can reduce wear and damage due to the vibration of the engine 3.

  In some embodiments, as shown in FIG. 4, the exhaust gas pipe 6 is provided with a heat insulation device 9. In the embodiment shown in FIG. 4, the heat insulation device 9 includes a cladding tube 91 that covers the outer circumference of the exhaust gas tube 6. In another embodiment, the heat insulating device 9 is a heat insulating material attached to the outer periphery of the exhaust gas pipe 6. In this case, since the temperature decrease of the exhaust gas flowing through the exhaust gas pipe 6 can be suppressed by the heat insulating device 9, the heating device 7 may be a small-sized one with low heating performance. For this reason, the enlargement of the heating device 7 can be prevented.

  Although the heating device 7 includes the second DOC 71 in some embodiments described above, the heating device 7 may also include a heater wound around the outer periphery of the exhaust gas pipe 6 and a burner for heating the exhaust gas pipe 6 Good. The heating device 7 may be provided in the exhaust gas pipe 6 located outside the engine room 21.

  Although the forklift 10A has been described in the above-described embodiments, the vehicle 1 may be a cargo handling vehicle 10 such as a shovel loader other than the forklift 10A, or a vehicle other than the cargo handling vehicle 10 May be In addition, the exhaust gas treatment system 4 is not limited to the vehicle 1 as long as it has the engine 3. For example, it may be a facility having the engine 3 or the like.

  The present invention is not limited to the above-described embodiments, and includes the embodiments in which the above-described embodiments are modified, and the embodiments in which these embodiments are appropriately combined.

Reference Signs List 1 vehicle 10 cargo handling vehicle 10A forklift 11 cargo handling device 12 counter weight 120 internal space 121 upper wall 122 rear wall 123, 124 side wall 125 bottom 2 vehicle main body 21 engine room 211 upper wall 212 front wall 213, 214 sidewall 215 bottom 22, 23 support bracket 25 intake pipe 26 intake manifold 27 intake throttle valve 28 fuel injection valve 29 exhaust pipe injection valve 3 engine 31 engine main body 311 combustion chamber 32 alternator 33 engine bracket 34 exhaust throttle valve 35 turbocharger 351 exhaust turbine 352 compressor 36 radiator 37 oil cooler 38 precleaner 39 air cleaner 4 exhaust gas treatment system 41 second DOC inlet temperature sensor 42 first DOC inlet temperature sensor 43 DPF Mouth temperature sensor 44 DPF outlet temperature sensor 45 DPF inlet pressure sensor 46 DPF outlet pressure sensor 47 DPF differential pressure sensor 5 an exhaust gas processing device 51 first 1DOC
511 Oxidation catalyst 52 DPF
53 exhaust gas pipe 54 exhaust gas exhaust pipe 6 exhaust gas pipe 61 bellows 7 heating device 71, 71A, 71B second DOC
711 oxidation catalyst 8 control device 80 injection control unit 81 main injection control unit 82 post injection control unit 83 exhaust gas pipe injection control units 84A, 84B heat amount control unit 9 heat insulation device 91 cladding tube

Claims (11)

With the engine,
A vehicle body having an engine room for housing the engine;
An exhaust gas processing device disposed outside the engine room in the vehicle body, the DPF capable of collecting PM in exhaust gas discharged from the engine, and an upstream side of the DPF in the flow direction of the exhaust gas An exhaust gas treatment device including a first DOC disposed in
An exhaust gas pipe for flowing the exhaust gas discharged from the engine to the first DOC;
A vehicle comprising: at least one heating device provided in the exhaust gas pipe for heating the exhaust gas flowing through the exhaust gas pipe. The vehicle according to claim 1, wherein the at least one heating device includes a plurality of heating devices. The vehicle according to claim 1, wherein the at least one heating device includes at least one second DOC disposed inside the engine room. And a controller for controlling the engine.
The control device includes a post injection control unit that controls execution of post injection for supplying unburned fuel to the first DOC and the second DOC,
At the time of forced regeneration of the DPF, the post injection control unit
A first step of raising the temperature of the second DOC to the activation temperature by raising the temperature of the exhaust gas at the outlet of the engine by injecting fuel into the combustion chamber of the engine;
After the first step, a second step of raising the first DOC to an activation temperature by supplying a predetermined amount of unburned fuel to the second DOC, and after the second step, the second DOC is sent to the first DOC. A third step of forced regeneration of the DPF by supplying more unburned fuel than the predetermined amount;
The vehicle of claim 3 configured to perform. The vehicle according to claim 3 or 4, wherein the amount of precious metal catalyst contained in the second DOC is 1/50 or more and 1/5 or less of the amount of precious metal catalyst contained in the first DOC. The external dimension D in the direction orthogonal to the axis of the second DOC satisfies D ≦ D0, where D0 is the external dimension in the direction orthogonal to the axis of the first DOC. Vehicle. A controller for controlling the engine;
A second exhaust gas temperature detection device that detects the temperature of the exhaust gas supplied to the first DOC;
The controller is
The vehicle according to any one of claims 1 to 6, further comprising a heat amount control unit configured to control a heat amount applied to the exhaust gas by the at least one heating device according to a detection result of the second exhaust gas temperature detection device. A controller for controlling the engine;
A first exhaust gas temperature detection device for detecting the temperature of the exhaust gas discharged from the engine;
A second exhaust gas temperature detection device that detects the temperature of the exhaust gas supplied to the first DOC;
The control device includes a heat amount control unit that controls the amount of heat added to the exhaust gas by the at least one heating device according to the detection results of the first exhaust gas temperature detection device and the second exhaust gas temperature detection device. The vehicle according to any one of 1 to 6. A cargo handling vehicle including the vehicle according to any one of claims 1 to 8, comprising:
The cargo handling vehicle is
A cargo handling device provided in front of the engine room;
And a counterweight provided rearward of the engine room to limit movement of the center of gravity of the cargo handling vehicle.
The loading and unloading vehicle is disposed in an internal space defined by the counterweight. The cargo handling vehicle is
The cargo handling vehicle according to claim 9, further comprising: a radiator disposed between the internal space defined by the counterweight and the engine room to separate the internal space from the engine room. An exhaust gas processing apparatus for treating exhaust gas discharged from an engine, comprising: a DPF capable of collecting PM in the exhaust gas; and a first DOC disposed upstream of the DPF in the flow direction of the exhaust gas An exhaust gas treatment device,
An exhaust gas pipe for flowing the exhaust gas discharged from the engine to the first DOC;
An exhaust gas processing system, comprising: a heating device provided in the exhaust gas pipe and heating the exhaust gas flowing through the exhaust gas pipe in order to compensate the heat radiation loss of the exhaust gas flowing through the exhaust gas pipe.

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