JP2015117597A - Work vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a work vehicle capable of downsizing and simplifying a supporting structure of a first case 62 and a second case 63, and easily improving the assembling workability of the second case 63 or an urea mixing pipe 73.SOLUTION: A work vehicle includes: an operating portion 7 on which an operator boards, a first case 62 for removing particulate substances in exhaust gas of an engine 5, a second case 63 for removing nitrogen oxide substances in the exhaust gas of the engine 5, an urea mixing pipe 73 for connecting the second case 63 to the first case 62; and an urea water tank 91 for supplying urea water to the urea mixing pipe 73. The first case 62 and the second case 63 are attached on a rear side of the engine 5 in a laterally long posture, and the supporting height of the second case 63 is formed to be lower than the supporting height of the first case 62.

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 work vehicle such as a tractor provided with an exhaust gas purifying 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

  In Patent Document 2, the exhaust pipe that supplies exhaust gas from the engine to the catalyst case is formed by a case support member that attaches the catalyst case to the traveling machine body, so that the case support has a special structure corresponding to the traveling machine body structure and the like. It is difficult to easily reduce the manufacturing cost and the structure in which the catalyst case is separated from the engine, and it is difficult to easily secure the exhaust gas temperature necessary for purifying the exhaust gas. There is a problem that the exhaust gas purification function for removing substances cannot be improved. In addition, when working in a cold region, there is a problem that it is difficult to maintain the temperature of the urea aqueous solution necessary for exhaust gas purification, and the urea water is easily crystallized before ammonia is formed.

  Therefore, the present invention seeks to provide a work vehicle that has been improved by examining these current conditions.

  In order to achieve the above object, a work vehicle according to a first aspect of the present invention includes a driving unit on which an operator is boarded, a first case for removing particulate matter in engine exhaust gas, and an engine exhaust gas in engine exhaust gas. In a work vehicle comprising a second case for removing nitrogen oxides, a urea mixing pipe connecting the second case to the first case, and a urea water tank for supplying urea water to the urea mixing pipe, a rear portion of the engine The first case and the second case are mounted in a horizontally long posture, and the support height of the second case is formed lower than the support height of the first case.

  According to a second aspect of the present invention, in the work vehicle according to the first aspect, the upper surface side of the engine is covered with a bonnet, and the engine rear portion is formed in the engine room formed by the bonnet. The first case, the second case, and the urea mixing tube are arranged in parallel to each other.

  According to a third aspect of the present invention, in the work vehicle according to the first aspect, a case support is projected upward and rearward from the rear portion of the engine, and the upper case support is provided on the upper side of the engine. The first case is attached, and the second case is attached to the upper side of the flywheel via a rear-facing case support.

  According to a fourth aspect of the present invention, in the work vehicle according to the first aspect, the left and right vehicle body frames that connect the front end side to the engine, and the transmission case that connects to the rear end sides of the left and right vehicle body frames, In the structure that constitutes the traveling machine body, a urea water tank is disposed on the lower side of the step of a driving unit on which an operator gets on, and a urea water tank is attached between the left and right body frames.

  According to the first aspect of the present invention, the operating unit on which the operator is boarded, the first case for removing particulate matter in the exhaust gas of the engine, and the second for removing nitrogen oxides in the exhaust gas of the engine. In a work vehicle comprising a case, a urea mixing pipe connecting the second case to the first case, and a urea water tank for supplying urea water to the urea mixing pipe, the first case and the second Since the case is mounted in a horizontally long posture and the support height of the second case is formed lower than the support height of the first case, the first case and the second case are disposed at the highly rigid engine rear portion. The support structure for the first case and the second case can be simplified in size, and the urea mixing tube can be easily arranged on the upper surface side of the second case, and the second case or the urea Workability of assembling the coupling pipe can be easily improved.

  According to a second aspect of the present invention, the upper surface side of the engine is covered with a bonnet, and the first case and the second case are disposed in the engine rear portion of the engine room formed by the bonnet. And the urea mixing pipe are arranged in parallel to each other, so that the first case, the second case, and the urea mixing pipe can be brought close to each other in the space behind the engine inside the engine room, and can be compactly supported. The exhaust gas temperature required for exhaust gas purification can be easily secured, and the exhaust gas purification function for removing nitrogen oxides in the exhaust gas can be improved.

  According to the invention of claim 3, a case support is protruded upward and rearward from the rear portion of the engine, and the first case is attached to the upper side of the engine via the upward case support, Since the second case is attached to the upper side of the flywheel via a rear-facing case support, it is not necessary to form the case support member in a special structure, and the manufacturing cost cannot be easily reduced. Since the cooling air of the engine is blown to the second case and the urea mixing pipe, the exhaust gas temperature necessary for the purification of the exhaust gas can be easily secured, for example, the purification of the exhaust gas even in work in a cold region. Therefore, it is possible to easily maintain the temperature of the urea aqueous solution necessary for the crystallization of the urea water before ammonia is formed.

  According to the fourth aspect of the present invention, the traveling vehicle body is configured by the left and right body frames that connect the front end side to the engine and the transmission case that is connected to the rear end sides of the left and right body frames. Since the urea water tank is disposed on the lower side of the step of the driving unit on which the operator is boarded and the urea water tank is attached between the left and right body frames, power is transmitted from the engine to the transmission case. The urea water tank can be installed in a compact manner by effectively using the space where the main transmission shaft and the like are installed, and the support rigidity of the urea water tank can be easily improved. Protection can be easily achieved.

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. An oil cooler 42, an air cleaner 43, a battery 44, and the like are disposed on the front chassis 23 in front of the radiator 41. 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. 5, 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 elongated cylindrical shape that extends long in a direction crossing the output shaft (crankshaft) of the diesel engine 5 in a 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. One end side and the other end side of the first case 62 in the exhaust gas movement direction are detachably supported on the cylinder head 32 of the diesel engine 5 via the front support leg body 69 and the rear support leg body 70. That is, the first case 62 is attached to the rear portion on the upper surface side of the diesel engine 5 via the front support leg body 69 and the rear support leg body 70. The longitudinal direction of the cylindrical first case 62 faces the left and right direction of the diesel engine 5 and the first case 62 is supported in a direction crossing the exhaust manifold 36.

  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 horizontally long elongate cylindrical shape extended long in the left-right direction. An SCR inlet pipe 74 for taking in exhaust gas is provided on the left 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 right end side of the cylindrical shape of the second case 63, and an exhaust pipe 77 is connected to the SCR outlet pipe 76 via a bellows-like connecting pipe 75 that can be bent and stretched. The lower end side of the tail pipe 81 is connected to the air pipe via the exhaust pipe 77. 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. Mechanical vibration on the diesel engine 5 side is blocked by the bellows-like connecting pipe 75 and is not transmitted to the exhaust pipe 77 side.

  A case mounting bracket 83 is fixed to the rear support leg 70, and the second case 63 is detachably mounted to the case mounting bracket 83. The rear side of the diesel engine 5 (the upper surface side of the flywheel 38) In addition, a cylindrical first case 28 that is long, a cylindrical urea mixing tube 73 that is long in the left-right direction, and a cylindrical second case 63 that is long in the left-right direction are arranged in parallel. A urea mixing pipe 73 is arranged on the rear side of the first case 28, a second case 63 is arranged on the lower side of the urea mixing pipe 73, and a urea mixing pipe is installed in the space between the rear surface of the diesel engine 5 and the front surface of the operation cabin 7. 73 and the second case 63 are supported.

  Accordingly, the first case 62 is disposed horizontally (horizontally long) on the upper surface side of the diesel engine 5, while the urea mixing pipe 73 and the second case 63 are horizontally disposed on the rear side of the diesel engine 5 ( The first case 62 and the second case 63 can be arranged in a compact manner inside the hood 6 while being arranged in a horizontally long posture and capable of functionally forming the exhaust gas movement path of the diesel engine 5.

  Further, a urea water tank 91 is mounted on the traveling machine body 2 below the operation cabin 7 via the tank mount 90. A water injection port 92 for the urea water tank 91 is provided on the upper surface side of the boarding step 11 of the operation cabin 7. Since the urea water tank 91 is installed on the lower side of the blowout of the cooling air discharged to the rear of the diesel engine 5, the urea water tank 91 is heated by the cooling air of the diesel engine 5, so that even when working in a cold region In addition, the temperature of the urea aqueous solution in the urea water tank 91 can be easily maintained, and the crystallization of the urea water can be reduced. In addition, a main transmission shaft 45, a front wheel drive shaft 46, and a urea water tank 91 are disposed between the diesel engine 5 and the transmission case 17. Therefore, the urea water tank 91 can be compactly supported in the space where the main transmission shaft 45 and the front wheel drive shaft 46 are installed.

  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.

  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. An operation including a second case 63 for removing nitrogen oxides in the gas, a urea mixing pipe 73 for connecting the second case 63 to the first case 62, and a urea water tank 91 for supplying urea water to the urea mixing pipe 73. In the vehicle, the first case 62 and the second case 63 are attached to the rear portion of the diesel engine 5 in a horizontally long posture, and the support height of the second case 63 is formed lower than the support height of the first case 62. . Therefore, the first case 62 and the second case 63 can be installed at the rear portion of the high-rigidity diesel engine 5, the support structure of the first case 62 and the second case 63 can be simplified and the upper surface side of the second case 63, etc. In addition, the urea mixing tube 73 can be easily arranged, and the assembly workability of the second case 63 or the urea mixing tube 73 can be easily improved.

  As shown in FIGS. 4 to 6, the upper surface side of the diesel engine 5 is covered with the bonnet 6, and the first case 62 and the second case 62 are formed at the rear of the diesel engine 5 in the engine room formed by the bonnet 6. The case 63 and the urea mixing tube 73 are arranged in parallel to each other. Accordingly, the first case 62, the second case 63, and the urea mixing pipe 73 can be compactly supported in the space behind the diesel engine 5 in the engine room, and the exhaust gas necessary for purifying the exhaust gas. The temperature can be easily secured and the exhaust gas purification function for removing nitrogen oxides in the exhaust gas can be improved.

  As shown in FIGS. 4 to 6, a case support (front support leg body 69, rear support leg body 70, case mounting bracket 83) is protruded upward and rearward from the rear part of the diesel engine 5, and is located on the upper side of the diesel engine 5. The first case 62 is attached via an upward case support (front support leg 69, rear support leg 70), and the second case via a rear case support (case mounting bracket 83) on the upper side of the flywheel 38. A case 63 is attached. Therefore, it is not necessary to form the front support leg 69 or the rear support leg 70 or the case mounting bracket 83 in a special structure, and the manufacturing cost cannot be easily reduced. In addition, the diesel engine 5 is included in the second case 63 and the urea mixing pipe 73. As the cooling air is blown, the exhaust gas temperature required for exhaust gas purification can be easily secured.For example, the temperature of the urea aqueous solution required for exhaust gas purification can be easily maintained even when working in cold regions. It is possible to easily prevent the urea water from crystallizing before ammonia is formed.

  As shown in FIGS. 4 to 6, a structure in which the traveling machine body 2 is configured by a left and right vehicle body frame 23 that connects the front end side to the diesel engine 5 and a transmission case 17 that is connected to the rear end side of the left and right vehicle body frame 23. The urea water tank 91 is arranged on the lower surface side of the boarding step 11 of the driving cabin 7 on which the operator is boarded, and the urea water tank 91 is attached between the left and right body frames 23. Therefore, the urea water tank 91 can be installed in a compact manner by effectively using the space where the main transmission shaft 45 for transmitting power from the diesel engine 5 to the transmission case 17 is installed, the support rigidity of the urea water tank 91, etc. The urea water tank 91 can be easily warmed or protected.

2 Driving body 5 Diesel engine 6 Bonnet 7 Driving cabin (operating part)
11 Boarding Step 17 Mission Case 23 Body Frame 38 Flywheel 62 First Case 63 Second Case 73 Urea Mixing Tube 69 Front Leg (Case Support)
70 Rear support leg (case support)
83 Case mounting bracket (case support)
91 Urea water tank

Claims (4)

An operating unit on which the operator is boarded, a first case for removing particulate matter in the exhaust gas of the engine, a second case for removing nitrogen oxides in the exhaust gas of the engine, and a second case in the first case. In a work vehicle including a urea mixing pipe that connects a case and a urea water tank that supplies urea water to the urea mixing pipe,
A work vehicle in which the first case and the second case are mounted in a horizontally long posture at a rear portion of the engine, and the support height of the second case is formed lower than the support height of the first case.   The upper surface side of the engine is covered with a bonnet, and the first case, the second case, and the urea mixing pipe are arranged in parallel to each other at the rear of the engine in the engine room formed by the bonnet. The work vehicle according to claim 1.   A case support body is provided so as to project upward and rearward from the rear part of the engine, and the first case is attached to the upper side of the engine via the upward case support body, and the rear case support body is provided to the upper side of the flywheel. 2. The work vehicle according to claim 1, wherein the second case is attached via a bracket. Steps of a driving unit on which an operator is boarded, which is a structure that constitutes the traveling vehicle body by left and right body frames that connect the front end side to the engine and a transmission case that is connected to the rear end sides of the left and right body frames. The work vehicle according to claim 1, wherein a urea water tank is disposed on a lower surface side, and a urea water tank is attached between the left and right body frames.

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