JP6177118B2 - Tractor - Google Patents

Description

The present invention relates to a work vehicle such as an agricultural machine (tractor, combine) or a construction machine (bulldozer, hydraulic excavator, loader) equipped with an engine, and more specifically, particulate matter (soot, contained in exhaust gas). The present invention relates to a tractor provided with an exhaust gas purification device for removing particulate oxide or nitrogen oxides (NOx) contained in the exhaust gas.

  In a work vehicle such as a tractor or wheel loader, an opening / closing fulcrum shaft is arranged at the rear of the bonnet for covering the engine in order to improve the efficiency of maintenance work of the engine arranged at the front of the traveling machine body. The bonnet was rotated. Conventionally, a filter case having a diesel particulate filter and a catalyst case having a urea selective reduction catalyst are provided as exhaust gas purifiers (exhaust gas aftertreatment devices) in the exhaust path of a diesel engine. There has been known a technique for purifying exhaust gas discharged from a diesel engine by providing exhaust gas into a filter case and a catalyst case (see, for example, Patent Document 1 or 2).

JP 2009-74420 A US Patent Application Publication No. 2011/283687

  When the catalyst case is assembled away from the engine as in Patent Document 2, an exhaust pipe for supplying exhaust gas from the engine to the catalyst case is formed by a support member that supports the catalyst case on the traveling machine body. Therefore, there is a problem that it is necessary to form the support member in a special structure, and the manufacturing cost cannot be easily reduced. Also, in the structure in which urea water in the urea water tank is supplied to the urea mixing pipe, the urea water tank is installed using a space such as below the operation unit. There is a problem that the temperature of urea water supplied to the urea mixing pipe needs to be specially provided.

Therefore, the present invention seeks to provide an improved tractor by examining these current conditions.

In order to achieve the above object, the present invention relates to an operating unit on which an operator is boarded, a first case constituting a diesel particulate filter that removes particulate matter in the exhaust gas of the engine, and the exhaust gas of the engine In a tractor comprising a second case having a urea selective reduction catalyst for removing nitrogen oxides, wherein the first case and the second case are connected by a urea mixing pipe, the forward axis direction of the tractor is set forward, and the output shaft core wire The operation unit is disposed behind the hood where the engine is disposed in the front-rear direction, and the first case, the second case, and the urea mixing pipe are disposed together with the engine in the bonnet. cage, wherein the first case is configured to elongate cylindrical output axial line parallel to the direction of the engine in plan view, of the engine Shi The upper surface side of the cylinder head, is detachably supported by the support leg body, and the second case is Rutotomoni attached to up and down direction vertical posture on the rear side of the engine, the upper portion of the second case A urea mixing pipe is connected so that the exhaust gas can move from the upper part to the lower part of the second case, the first case and the urea mixing pipe are attached to the upper surface side of the engine, and the output of the engine The first case and the urea mixing tube are provided in parallel to the shaft core.

In the tractor , a urea water tank is disposed on the rear side of the engine room inside the hood where the engine is disposed, and the urea water tank is supported adjacent to the second case.

According to the present invention, there is provided an operating unit on which an operator gets on, a first case for removing particulate matter in the exhaust gas of the engine, and a second case for removing nitrogen oxides in the exhaust gas of the engine, In the tractor connecting the first case and the second case with a urea mixing pipe, the second case is mounted in a vertically long posture on the rear side of the engine, and the exhaust gas can be moved in the vertical direction of the second case. Therefore, the second case can be installed on the highly rigid engine or traveling machine body, the support structure of the second case can be simplified and simplified, and the urea mixing tube can be provided on the upper surface side of the engine. It can be easily arranged, and the workability of assembling the second case or the urea mixing tube can be easily improved. In addition, heating or protection of the second case can be easily achieved.

According to the present invention, the first case and the urea mixing tube are arranged in a U-shape in the front-rear orientation on the upper surface side of the engine, and the first case and the second case are arranged in an L shape in a side view. Therefore, while the exhaust gas movement distance of the urea mixing pipe can be formed to a length that allows ammonia to be appropriately generated in the exhaust gas supplied to the second case, the second case or the The temperature drop of the urea mixing tube can be easily reduced, and urea crystallization at the connecting portion of the urea mixing tube can be easily prevented.

According to the present invention, the first case is connected to the upper part of the second case, and the exhaust gas can be moved from the upper part to the lower part of the second case. Since one case and a urea mixing pipe are attached, and the first case and the urea mixing pipe are provided in parallel with the output shaft core line of the engine, the space on the upper surface side of the engine is utilized to The urea mixing pipe can be supported in a compact manner, and assembly workability such as piping work for connecting the urea mixing pipe to the second case disposed on the rear side of the engine can be easily improved.

According to the present invention, the urea water tank is disposed on the rear side of the engine room inside the hood where the engine is disposed, and is configured to support the urea water tank adjacent to the second case. Thus, the urea water tank can be compactly arranged inside the engine room on the side of the second case, and the urea water tank and the urea mixing pipe are heated by the heat generated on the engine side, so that the operation in a cold district is performed. Even so, the temperature of the urea aqueous solution in the urea mixing tube can be easily maintained, crystallization of urea water in the urea mixing tube can be reduced, and nitrogen oxides in the exhaust gas in the second case can be removed. The exhaust gas hatching function can be improved.

It is a left view of the tractor which shows 1st Embodiment. It is the same top view. It is the same right view. It is a left view of a tractor front part. It is a top view of the same part. It is a right view of the same part.

  Below, 1st Embodiment which actualized this invention is described based on drawing (FIGS. 1-6). First, a farm tractor 1 equipped with a diesel engine will be described with reference to FIGS. A farm tractor 1 as a work vehicle shown in FIGS. 1 to 3 is configured to perform a plowing work and the like for plowing a farm field by mounting a plow working machine (not shown). 1 is a left side view of the tractor 1, FIG. 2 is a plan view thereof, and FIG. 3 is a right side view thereof. In the following description, the left side in the forward direction of the tractor 1 is simply referred to as the left side, and the right side in the forward direction is also simply referred to as the right side.

  As shown in FIGS. 1 to 3, a farm tractor 1 as a work vehicle supports a traveling machine body 2 with a pair of left and right front wheels 3 and a pair of left and right rear wheels 4, and a diesel engine at the front of the traveling machine body 2. 5 and driving the rear wheel 4 and the front wheel 3 with the diesel engine 5, the vehicle is configured to travel forward and backward. The upper surface side and the left and right side surfaces of the diesel engine 5 are covered with an openable / closable bonnet 6.

  In addition, on the upper surface of the traveling machine body 2, behind the hood 6, a driving cabin 7 is installed as a driving unit on which an operator gets on. Inside the cabin 7 is provided a front column 10 including a control seat 8 on which an operator sits, a control handle 9 as steering means, and the like. Further, left and right boarding steps 12 are provided outside the boarding step 11 at the bottom of the cabin 7. In the front column 10, left and right brake pedals 13, a clutch pedal 14, a transmission pedal 15, a forward / reverse switching lever 16 and the like are disposed as steering devices.

  The traveling machine body 2 also includes a mission case 17 for shifting the output from the diesel engine 5 and transmitting it to the rear wheels 4 (front wheels 3). The rear of the mission case 17 is connected to a tiller mechanism (not shown) and the like via a traction mechanism 21 such as a left and right lower link 18, a top link 19, and a left and right lift arm 20, and the like. The PTO shaft 22 provided on the rear side surface of 17 is configured to drive the tilling work machine and the like. Furthermore, the traveling machine body 2 of the tractor 1 includes a diesel engine 5, a transmission case 17, a vehicle body frame 23 that connects them, a front chassis 24 that extends forward from the diesel engine 5, and the like. A pair of left and right boarding steps 12 for the operator to get on and off are disposed on the left and right outer portions of the cabin 7.

  Next, the diesel engine 5 and the exhaust gas discharge structure will be described with reference to FIGS. As shown in FIGS. 3 to 5, an intake manifold 33 is disposed on one side surface of the cylinder head 32 of the diesel engine 5. The cylinder head 32 is mounted on a cylinder block 35 in which an engine output shaft 34 (crankshaft) and a piston are built. An exhaust manifold 36 is disposed on the other side surface of the cylinder head 32, and a front end and a rear end of the engine output shaft 34 are projected from the front and rear surfaces of the cylinder block 35.

  As shown in FIGS. 4 to 6, a flywheel 38 is fixed to the rear end of the engine output shaft 34. The left and right side surfaces of the cylinder block 35 are connected to the front end portions of the left and right body frame 23 made of steel plate. Further, an oil pan 39 is disposed on the lower surface of the cylinder block 35, a cooling fan 40 is disposed on the front surface side of the cylinder block 35, and a radiator 41 is installed facing the cooling fan 40. On the front chassis 24 in front of the radiator 41, an oil cooler 42, an air cleaner 43, a battery 44, and the like are arranged. Further, a main transmission shaft 45 that takes out the power of the diesel engine 5 from the rear end side of the engine output shaft 34 on which the flywheel 38 is pivotally supported toward the transmission case 17, and a diesel engine from the transmission case 17 toward the front wheel 3. A front wheel drive shaft 46 for taking out the motive power 5 is disposed between the left and right body frames 23.

  As shown in FIGS. 4 to 6, an exhaust gas recirculation device (EGR) 47 that takes in exhaust gas for recirculation is disposed in the intake manifold 33. An air cleaner 43 is connected to the intake manifold 33 via an exhaust gas recirculation device 47. The external air that has been dedusted and purified by the air cleaner 43 is sent to the intake manifold 33 and supplied to each cylinder of the diesel engine 5.

  With the above configuration, a part of the exhaust gas discharged from the diesel engine 5 to the exhaust manifold 36 is recirculated from the intake manifold 33 to each cylinder of the diesel engine 5 via the exhaust gas recirculation device 47. The combustion temperature of the diesel engine 5 is lowered, the amount of nitrogen oxide (NOx) discharged from the diesel engine 5 is reduced, and the fuel efficiency of the diesel engine 5 is improved.

  The diesel engine 5 is cooled by the cooling fan 40 wind. Further, as shown in FIG. 6, each of the injectors (not shown) for the four cylinders of the diesel engine 5 includes a fuel pump 52 and a common rail 53 that connect a fuel tank (not shown). A common rail 53 and a fuel filter 54 are arranged on the intake manifold 33 installation side of the cylinder head 32, and a fuel pump 52 is arranged in the cylinder block 35 below the intake manifold 33.

  The high-pressure fuel is temporarily stored in the common rail 53, the high-pressure fuel in the common rail 53 is supplied into each cylinder of the diesel engine 5, and the fuel injection valves of the injectors are controlled to open and close. As a result, the high-pressure fuel in the common rail 53 is injected into each cylinder of the diesel engine 5. That is, by electronically controlling the fuel injection valve of each injector, the fuel injection pressure, injection timing, and injection period (injection amount) can be controlled with high accuracy. Therefore, nitrogen oxides (NOx) discharged from the diesel engine 5 can be reduced.

  As shown in FIGS. 4 to 6, as an exhaust gas purifying device 61 for purifying exhaust gas discharged from each cylinder of the diesel engine 5, diesel particulates that remove particulate matter in the exhaust gas of the diesel engine 5 are used. A first case 62 as a curate filter (DPF) and a second case 63 as a urea selective catalytic reduction (SCR) system for removing nitrogen oxides in exhaust gas of the diesel engine 5 are provided. As shown in FIG. 4, an oxidation catalyst 64 and a soot filter 65 are provided in the first case 62. The second case 63 includes an SCR catalyst 66 and an oxidation catalyst 67 for reducing urea selective catalyst.

  Exhaust gas discharged from each cylinder of the diesel engine 5 to the exhaust manifold 36 is discharged to the outside via the exhaust gas purification device 61 and the like. The exhaust gas purification device 61 is configured to reduce carbon monoxide (CO), hydrocarbons (HC), particulate matter (PM), and nitrogen oxides (NOx) in the exhaust gas of the diesel engine 5. doing.

  The first case 62 is configured in a horizontally long long cylindrical shape extending long in a direction parallel to the output shaft (crankshaft) of the diesel engine 5 in plan view. A DPF inlet pipe 68 for taking in exhaust gas is provided on one end of the first case 62 in the cylindrical shape. Of the front and rear surfaces of the diesel engine 5, the one end side and the other end side of the first case 62 in the exhaust gas movement direction can be attached to and detached from the front and rear surfaces of the cylinder head 32 via the front support leg body 69 and the rear support leg body 70. I support it. That is, the first case 62 is attached to the upper surface side of the diesel engine 5 through the front support leg 69 and the rear support leg 70. The first case 62 is supported in parallel with the exhaust manifold 36 (engine output shaft 34) with the longitudinal direction of the cylindrical first case 62 facing the front-rear direction of the diesel engine 5.

  Further, the DPF inlet pipe 68 is communicated with the exhaust gas outlet of the exhaust manifold 36, and the exhaust gas of the diesel engine 5 is introduced from the DPF inlet pipe 68 into the first case 62. On the other hand, a DPF outlet pipe 72 for discharging exhaust gas is provided on the other end side of the cylindrical shape of the first case 62. The DPF outlet pipe 72 of the first case 62 is connected to the inlet side of the urea mixing pipe 73, and the exhaust gas of the first case 28 is introduced into the urea mixing pipe 73.

  On the other hand, the 2nd case 63 is comprised in the vertically long elongate cylindrical shape extended long in the up-down direction. An SCR inlet pipe 74 for taking in exhaust gas is provided on the upper front end side of the cylindrical shape of the second case 63, and the SCR inlet pipe 74 is connected to the outlet side of the urea mixing pipe 73. On the other hand, an SCR outlet pipe 76 is provided on the cylindrical lower end side of the second case 63, and the lower end side of the tail pipe 81 is connected to the SCR outlet pipe 76 via a bellows-like connecting pipe 75 that can be bent and stretched. The tail pipe 81 is erected substantially vertically along the right corner of the operation cabin 7. A tail pipe 81 and a pipe cover 82 are fixed to the right corner of the operation cabin 7.

  Further, the cylindrical lower end portion of the second case 63 is detachably fixed to the rear side surface of the diesel engine 5 via the case mounting bracket 83. Mechanical vibration on the diesel engine 5 side is blocked by the bellows-like connecting pipe 75 and is not transmitted to the tail pipe 81 side. A main transmission shaft 45 that is connected to the engine output shaft 34 via a flywheel 38 and a front wheel drive shaft 46 that drives the front wheels 3 are arranged in parallel between the left and right body frames 23, and the main transmission shaft is arranged. The driving force of the diesel engine 5 is input to the mission case 17 via 45, and the front wheel driving force of the mission case 17 is output to the front wheel 3 via the front wheel drive shaft 46.

  Accordingly, the first case 62 and the urea mixing pipe 73 are horizontally arranged in the front-rear direction (horizontal orientation) on the upper surface side of the diesel engine 5, while the second case 63 is supported in the portrait orientation at the rear of the diesel engine 5. A urea water tank 91, which will be described later, is disposed adjacent to the second case 63, and the exhaust gas movement path of the diesel engine 5 can be functionally formed. The case 63, the urea mixing pipe 73, and the urea water tank 91 can be arranged in a compact manner.

  Further, a urea water tank 91 is mounted on the rear side of the diesel engine 5 via a case mounting bracket 83, and the urea water tank 91 is fixed to the rear part of the diesel engine 5. A water inlet 92 of the urea water tank 91 is provided below the rear part of the bonnet 6. The second case 63 and the urea water tank 91 are supported side by side on the rear side of the diesel engine 5 in the engine room formed by the hood 6. That is, since the second case 63 and the urea water tank 91 are installed between the front part of the front column 10 and the rear part of the diesel engine 5, heat generation and vibration generated on the diesel engine 5 side are absorbed by the urea water tank 91 and the like. Transmission to the column 10 side can be suppressed, and the urea mixing pipe 73 and the urea water tank 91 are heated by the heat generated on the diesel engine 5 side, so that urea in the urea water tank 91 can be used even in a cold region. The temperature of the aqueous solution can be easily maintained, and the crystallization of urea water can be reduced. Moreover, since a space for installing a partition material (a space for heat insulation and a space for vibration and soundproofing) is formed between the front column 10 and the diesel engine 5, the dead space can be used effectively so that the interior of the fuselage (engine The second case 63 and the urea water tank 91 can be compactly arranged in the room.

  Further, a urea water injection pump 94 that pumps the urea aqueous solution in the urea water tank 91, an electric motor 95 that drives the urea water injection pump 94, and urea that is connected to the urea water injection pump 94 via a urea water injection pipe 96. A water injection nozzle 97 is provided. A urea water injection nozzle 97 is attached to the urea mixing pipe 73, and a urea aqueous solution is sprayed from the urea water injection nozzle 97 into the urea mixing pipe 73. The urea water supplied into the urea mixing pipe 73 is configured to be mixed as ammonia in the exhaust gas from the first case 62 to the second case 63. In addition, the middle part of the urea water injection pipe 96 is bound and supported by a bonnet frame 98 for supporting the bonnet 6 so that it can be opened and closed around the rear fulcrum.

  With the above configuration, the oxidation catalyst 64 and the soot filter 65 in the first case 62 reduce carbon monoxide (CO) and hydrocarbons (HC) in the exhaust gas of the diesel engine 5. Next, urea water from the urea water injection nozzle 97 is mixed into the exhaust gas from the diesel engine 5 inside the urea mixing pipe 73. The SCR catalyst 66 and the oxidation catalyst 67 in the second case 63 reduce nitrogen oxides (NOx) in the exhaust gas in which urea water is mixed as ammonia. That is, exhaust gas with reduced carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx) is discharged from the tail pipe 81 to the outside of the machine.

  As shown in FIGS. 1 and 4 to 6, an operation cabin 7 as an operation unit on which an operator gets on, a first case 62 for removing particulate matter in exhaust gas of the diesel engine 5, and exhaust of the diesel engine 5. In a work vehicle having a second case 63 for removing nitrogen oxides in the gas and connecting the first case 62 and the second case 63 with a urea mixing pipe 73, the second case 63 is provided on the rear side of the diesel engine 5. The exhaust gas can be moved in the vertical direction of the second case 63 by being mounted in a vertically long posture. Therefore, the second case 63 can be installed on the high-rigidity diesel engine 5 or the traveling machine body 2, the support structure of the second case 63 can be simplified and the urea mixing pipe 73 can be easily provided on the upper surface side of the diesel engine 5, etc. Assembling workability of the second case 63 or the urea mixing tube 73 can be easily improved. In addition, the second case 63 can be easily heated or protected.

  As shown in FIGS. 4 to 6, the first case 62 and the urea mixing pipe 73 are arranged in a U-shape in the front-rear orientation on the upper surface side of the diesel engine 5, and the first case 62 and the second case 63 are viewed from the side. They are arranged in an L shape. Therefore, while the exhaust gas movement distance of the urea mixing pipe 73 can be formed to a length in which ammonia is properly generated in the exhaust gas supplied to the second case 63, the second case 63 or the urea mixing pipe 73 can be easily reduced, and urea crystallization at the connecting portion of the urea mixing tube 73 can be easily prevented.

  As shown in FIGS. 4 to 6, the first case 62 is connected to the upper part of the second case 63 so that the exhaust gas can move from the upper part to the lower part of the second case 63, and the upper surface of the diesel engine 5. The first case 62 and the urea mixing pipe 73 are attached to the side, and the first case 62 and the urea mixing pipe 73 are provided in parallel to the output shaft core line of the diesel engine 5. Therefore, the first case 62 and the urea mixing pipe 73 can be compactly supported by utilizing the space on the upper surface side of the diesel engine 5, and the urea mixing pipe 73 is connected to the second case 63 disposed on the rear side of the diesel engine 5. Assembly work such as piping work can be easily improved.

  As shown in FIGS. 4 to 6, a urea water tank 91 is disposed on the rear side of the engine room inside the hood 6 where the diesel engine 5 is disposed, and the urea water tank 91 is supported adjacent to the second case 63. It is configured. Therefore, the urea water tank 91 can be compactly arranged inside the engine room on the side of the second case 63, and the urea water tank 91 and the urea mixing pipe 73 are heated by the heat generated on the diesel engine 5 side. Even in this operation, the temperature of the urea aqueous solution in the urea mixing tube 73 can be easily maintained, the crystallization of urea water in the urea mixing tube 73 can be reduced, and the nitrogen in the exhaust gas in the second case 63 can be reduced. It is possible to improve the exhaust gas hatching function for removing the oxidizing substances.

5 Diesel engine 6 Bonnet 7 Driving cabin (driving part)
62 1st case 63 2nd case 73 Urea mixing pipe 91 Urea water tank

Claims (2)

An operating section on which an operator is boarded, a first case constituting a diesel particulate filter for removing particulate matter in engine exhaust gas, and a urea selective reduction catalyst for removing nitrogen oxides in the engine exhaust gas In a tractor comprising a second case provided, and connecting the first case and the second case with a urea mixing tube,
With the forward direction of the tractor as the front, the operating portion is disposed behind the hood where the engine with the output shaft core line in the front-rear direction is disposed, and the first case, the second case, And the urea mixing tube is disposed with the engine,
The first case has a cylindrical shape extending in a direction parallel to the output axis of the engine in plan view, and is detachably supported on the upper surface side of the cylinder head of the engine via a support leg. ,
And the second case is Rutotomoni attached to up and down direction vertical posture on the rear side of the engine, to connect the urea mixing tube in an upper portion of the second casing, directed from the top to the bottom of the second casing The exhaust gas can be moved
The tractor according to claim 1, wherein the first case and the urea mixing pipe are attached to an upper surface side of the engine, and the first case and the urea mixing pipe are provided in parallel to the output shaft core line of the engine.   2. The tractor according to claim 1, wherein a urea water tank is disposed on the rear side of the engine room inside the bonnet and is configured to support the urea water tank adjacent to the second case.

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