CN110651593A

CN110651593A - Combine harvester

Info

Publication number: CN110651593A
Application number: CN201910103373.4A
Authority: CN
Inventors: 上路嘉隆; 市丸智之; 上田光瑠
Original assignee: Iseki and Co Ltd
Current assignee: Iseki and Co Ltd
Priority date: 2018-06-28
Filing date: 2019-02-01
Publication date: 2020-01-07
Anticipated expiration: 2039-02-01
Also published as: CN209845731U; KR20200001963A; TW202000004A; CN110651593B; TWI790341B; JP6566335B1; JP2020000109A

Abstract

The invention provides a combine harvester, which can ensure the storage capacity of a grain bin and easily supply urea water solution to a urea water tank. The combine harvester is provided with an exhaust purification device (20) for purifying the exhaust gas of the engine (E), wherein the exhaust purification device (20) is provided with: an oxidation catalyst (21) that oxidizes unburned gas in exhaust gas discharged from an engine (E); and an SCR (22) for reducing and purifying nitrogen oxides in the exhaust gas after passing through the oxidation catalyst (21) by ammonia generated from the urea solution, wherein the combine harvester is provided with a urea water tank (25) for storing the urea solution supplied to the SCR (22), the urea water tank (25) is disposed at a position on the rear side of the rear wall of the grain bin (7) and outside the machine body of the trough (8A), and a water supply port (25A) of the urea water tank (25) is disposed toward the rear of the machine body.

Description

Combine harvester

Technical Field

The present invention relates to a combine harvester having an exhaust gas purification device.

Background

Conventionally, the following techniques are known: a combine harvester is provided with: an oxidation catalyst that oxidizes unburned gas in exhaust gas after combustion in an engine; and an SCR catalyst that purifies nitrogen oxides in the exhaust gas after passing through the oxidation catalyst, wherein a recess is formed in a rear wall of a grain bin that stores grains, and a urea water tank that stores an aqueous urea solution supplied to the SCR catalyst is disposed in the recess. (patent document 1)

Patent document 1: japanese patent laid-open publication No. 2017-104083

However, the technique disclosed in patent document 1 has the following problems: in order to form a recess in the rear wall of the grain bin, the storage capacity of the grain bin is reduced, and the harvesting operation must be frequently interrupted to perform the grain discharging operation, which results in a reduction in work efficiency.

Disclosure of Invention

Accordingly, a main object of the present invention is to provide a combine harvester capable of easily supplying an aqueous urea solution to a urea water tank while securing a storage capacity of a grain bin.

The present invention for solving the above problems is as follows.

That is, the invention of the first aspect is a combine harvester in which a threshing device (4) that threshes a grain stalk is provided on a body frame (1) on which an engine (E) is mounted, grain bins (7) that store grains after threshing are provided on each of the left and right sides of the threshing device (4), and a trough (8A) of a discharge screw conveyor (8) that discharges stored grains to the outside is disposed on the rear side of the grain bins (7), characterized in that,

the combine harvester is provided with an exhaust purification device (20) for purifying the exhaust gas of the engine (E), wherein the exhaust purification device (20) is provided with: an oxidation catalyst (21) that oxidizes unburned gas in exhaust gas discharged from the engine (E); and an SCR (22) for reducing and purifying nitrogen oxides in the exhaust gas after passing through the oxidation catalyst (21) by ammonia generated from the urea solution, wherein the combine harvester is provided with a urea water tank (25) for storing the urea solution supplied to the SCR (22), the urea water tank (25) is disposed at a position on the rear side of the rear wall of the grain bin (7) and outside the machine body of the trough (8A), and a water supply port (25A) of the urea water tank (25) is disposed toward the rear of the machine body.

The invention of the second aspect is a combine harvester, which is characterized in that a threshing device (4) for threshing a grain stalk is arranged on a machine body frame (1) provided with an engine (E), a grain bin (7) for storing threshed grains is arranged on each of the left and right sides of the threshing device (4), a winnowing portion (8A) of a discharge screw conveyor (8) for discharging the stored grains to the outside is arranged on the rear side of the grain bin (7),

the combine harvester is provided with an exhaust purification device (20) for purifying the exhaust gas of the engine (E), wherein the exhaust purification device (20) is provided with: an oxidation catalyst (21) that oxidizes unburned gas in exhaust gas discharged from the engine (E); and an SCR (22) for reducing and purifying nitrogen oxides in the exhaust gas after passing through the oxidation catalyst (21) by ammonia generated from the urea solution, wherein the combine harvester is provided with a urea water tank (25) for storing the urea solution supplied to the SCR (22), the urea water tank (25) is disposed at a position on the rear side of the rear wall of the grain bin (7) and outside the body of the trough (8A), and a water supply port (25A) of the urea water tank (25) is disposed at a position on the rear side of the trough (8A).

A third aspect of the invention is the combine harvester according to the first or second aspect, wherein a 1 st support base (33) for supporting the urea water tank (25) is provided, and the 1 st support base (33) is movable to the outside of the machine body.

A fourth aspect of the invention is the combine according to the third aspect, wherein the combine is provided with a 2 nd support base (46), the 2 nd support base (46) supports a tank storing urea water for replenishment when the urea water tank (25) is replenished with urea water, and the 2 nd support base (46) is provided so as to be switchable between a storage state and a use state.

The invention of a fifth aspect is the combine harvester according to the fourth aspect, wherein the combine harvester is provided with a support member (45) that supports an outer side portion of the urea water tank (25), and the 2 nd support table (46) is attached to a rear portion of the support member (45).

According to the invention described in the first aspect, since there is no need to form a recess in the rear wall of the grain bin 7, the storage capacity of the grain bin 7 can be secured, and the efficiency of harvesting work can be improved. Further, the space formed behind the rear wall of grain bin 7 can be utilized, and urea solution can be easily supplied from the rear of the machine body to urea solution tank 25.

According to the second aspect of the present invention, since there is no need to form a recess in the rear wall of the grain bin 7, the storage capacity of the grain bin 7 can be secured, and the efficiency of the harvesting operation can be improved. Further, the space formed behind the rear wall of the grain bin 7 can be utilized, and the urea water can be easily supplied to the urea water tank 25 from the water supply inlet 25A disposed on the rear side of the grain raising portion 8A.

According to the third aspect of the present invention, in addition to the effects of the first or second aspect of the present invention, the 1 st support base 33 supporting the urea water tank 25 can be moved outward of the machine body, and the work of attaching and detaching the trough 8A and the maintenance of the urea water tank 25 can be easily performed.

According to the invention of the fourth aspect, in addition to the effect of the invention of the third aspect, the urea solution can be easily supplied to the urea solution tank 25 by switching the 2 nd support base 46 to the use state and supporting the tank storing the urea solution on the 2 nd support base 46.

According to the invention described in the fifth aspect, in addition to the effect of the invention described in the fourth aspect, the 2 nd support table 46 can be easily switched from the rear to the storage state and the use state.

Drawings

Fig. 1 is a left side view of the combine harvester.

Fig. 2 is a right side view of the combine.

Fig. 3 is a right side view illustrating the purification apparatus.

Fig. 4 is a plan view illustrating the purification apparatus.

Fig. 5 is a right side view illustrating a urea water tank of the purification apparatus.

Fig. 6 is a plan view illustrating a urea water tank of the purification apparatus.

Fig. 7 is a rear view illustrating a urea water tank of the purification apparatus.

Fig. 8 is an enlarged view illustrating a right side view of the urea water tank.

Fig. 9 is an enlarged view illustrating a rear view of the urea water tank.

Fig. 10 is a plan view of the front panel and the side panels of the manipulating section.

Fig. 11 (a) is a plan view of the switch panel, and (b) is a right side view.

Fig. 12 (a) is a plan view of a grip portion of the main shift lever, (b) is a side view, (c) is a front view, (d) is a left side view, and (e) is a rear view.

Description of the reference symbols

1: a machine body frame; 4: a threshing device; 7: a grain bin; 8: a discharge screw conveyor; 8A: raising the valley part; 20: an exhaust gas purification device; 21: DOC (oxidation catalyst); 22: SCR; 25: a urea water tank; 25A: a water supply port; 33: a support table (1 st support table); 45: a support member; 46: a support table (2 nd support table); e: an engine.

Detailed Description

As shown in fig. 1 and 2, in the combine harvester, a traveling device 2 composed of a pair of right and left crawler belts that travel on the ground is provided on the lower side of a body frame 1, a harvesting device 3 that harvests grain stalks in the field is provided on the front side of the body frame 1, a threshing device 4 that performs threshing/screening processing on the harvested grain stalks is provided on the rear left side of the harvesting device 3, and a control unit 5 on which an operator rides is provided on the rear right side of the harvesting device 3.

An engine room 6 on which an engine E is mounted is provided below the manipulation unit 5, a grain bin 7 for storing grains subjected to threshing/screening processing is provided behind the manipulation unit 5, a discharge screw conveyor 8 for discharging the grains to the outside is provided behind the grain bin 7, and the discharge screw conveyor 8 is composed of a valley portion 8A extending in the vertical direction and a lateral discharge portion 8B extending in the front-rear direction.

As shown in fig. 3 to 7, the lower portion of the right wall of the threshing device 4 and the upper portion of the left wall of the grain bin 7 are communicated through a 1 st winnowing barrel 9, and the 1 st winnowing barrel 9 conveys the grains threshed/screened by the threshing device 4 to the grain bin 7. Further, a 2 nd winnowing barrel 10 for recovering 2-time screened materials such as attached branches and stalks to the threshing device 4 is provided behind the 1 st winnowing barrel 9.

Impurities in the exhaust gas after combustion in the engine E are purified by the exhaust gas purification device 20 and then discharged to the outside. The exhaust gas purification device 20 is constituted by: a DOC (in the claims, "oxidation catalyst") 21, which is a catalyst that oxidizes harmful components in exhaust gas; and an SCR (Selective Catalytic Reduction) 22 that reduces and purifies nitrogen oxides in the exhaust gas discharged from the DOC 21 by ammonia generated from an aqueous urea solution (hereinafter, also referred to as an aqueous urea solution), and the exhaust gas purification apparatus 20 includes: urea injection means 23 that injects urea water to SCR 22; a supply means 24 for feeding the urea solution under pressure to the urea injection means 23; and a urea water tank 25 that stores the urea water supplied to the supply means 24.

An exhaust port of the engine E and an intake port formed at a lower portion of the DOC 21 provided so that a flow direction of exhaust gas is directed in a vertical direction are connected by a flexible connection pipe 11. An exhaust port formed in the upper portion of the DOC 21 and an intake port formed in the rear portion of the SCR22 provided so that the flow direction of the exhaust gas is oriented in the front-rear direction are connected by a non-flexible connecting pipe 12, and a urea injection member 23 is provided at a position on the upstream side of the connecting pipe 12. An exhaust pipe (not shown) is connected to an exhaust port formed in the front portion of the SCR 22.

When the body is viewed from the side, the DOC 21 and SCR22 are arranged between the front wall of the grain bin 7 and the 1 st winnowing barrel 9. In the left-right direction, the DOC 21 and the SCR22 are provided between the right wall of the threshing device 4 and a bottom wall inclined higher left and lower right formed at the lower part of the left wall of the grain bin 7. Specifically, a recess is formed in a bottom wall inclined in a horizontal direction at a lower portion of a left wall of grain bin 7, and a part or all of DOC 21, connection pipe 12, and SCR22 enters the recess. This can prevent rainwater, direct sunlight, and high-pressure water from directly contacting the DOC 21 and the SCR22 during washing.

The water supply port of the urea injection member 23 and the water supply port of the supply member 24 are connected by a flexible connection pipe 13. Further, the front portion of the connection pipe 13 is provided at a position higher than the urea injection member 23. This prevents the air in the connection pipe 13 from staying in the front of the connection pipe 13 and being supplied to the urea injection member 23. Even when the urea aqueous solution is frozen, a predetermined amount of unfrozen urea aqueous solution can be fed under pressure to the urea injecting means 23. A connection pipe (not shown) for returning the cooling water heated by the engine E to the radiator is provided along the connection pipe 13. This prevents the urea solution in the connection pipe 13 from freezing, and can melt the urea solution in the frozen connection pipe 13 and the urea solution tank 25.

The supply member 24 is disposed in the vicinity of the side of the lower portion of the 2 nd winnowing barrel 10 in the front-rear direction. In the left-right direction, the supply member 24 is provided facing the bottom wall of the grain bin 7 formed to be inclined high on the left and low on the right. This makes it easy to provide the connection pipe 13 on the right side of the 1 st winnowing barrel 9 while bypassing the 1 st winnowing barrel 9. In addition, the space formed below the bottom wall of the grain bin 7 formed to be inclined in a manner of being higher on the left and lower on the right can be effectively utilized.

The water supply port of the supply member 24 and the water supply port of the urea water tank 25 are connected by a flexible connection pipe 14. The connection pipe 14 is provided above the supply member 24. This prevents the air in the connection pipe 14 from staying in the connection pipe 14 and being supplied to the supply member 24. Further, even when the urea aqueous solution is frozen, a predetermined amount of unfrozen urea aqueous solution can be supplied to the supply member 24. An on-off valve is provided in an internal pipe between the water supply port and the water supply port of the supply member 24, and a harness 15 for operating the on-off valve is connected to the on-off valve.

Accordingly, when the temperature of the urea water stored in the urea water tank 25 is lower or higher than the predetermined temperature, the supply of the urea water from the urea water tank 25 to the supply means 24 can be stopped by closing the on-off valve. The temperature of the urea aqueous solution is measured by a sensor 25B provided at the upper portion of the urea aqueous solution tank 25.

The urea water tank 25 is provided on the right side (outside the engine body) of the trough 8A so that the longitudinal direction thereof extends in the front-rear direction. When the body is viewed from the side, the urea water tank 25 is disposed on the rear side of the rear wall of the grain bin 7, and the rear portion thereof is disposed at a position overlapping with the support frame 30, and the support frame 30 rotatably supports the trough 8A about the vertical axis. A water supply port 25A of the urea water tank 25 is provided to protrude obliquely rearward and upward from an inclined wall formed at an upper rear portion of the urea water tank 25 and inclined rearward and downward.

Thus, the water supply port 25A is disposed toward the rear of the machine body at the rear of the machine body of the combine harvester. The water supply port 25A is disposed behind the grain raising portion 8A. When the body is viewed from the back, the urea water tank 25 is provided between the right wall of the grain bin 7 and the trough 8A.

This makes it possible to effectively utilize the space formed behind the rear wall of grain bin 7 and to easily supply urea water from water supply port 25A of urea water tank 25.

The water supply port of the urea water tank 25 is provided at a position higher than the water supply port of the supply member 24. This enables the space formed above the front communication portion 16 to be effectively utilized, and the urea solution can be easily supplied from the urea solution tank 25 to the supply member 24.

A support shaft 40 extending in the vertical direction is provided at the right end of the rear wall of grain bin 7.

An auger cover 41 is rotatably supported on the support shaft 40, and the auger cover 41 is formed of: a right cover 41A having a predetermined length in the vertical direction and extending in the front-rear direction; and a rear cover 41B extending in the left direction from the rear of the right cover 41A. In the stored state, right cover 41A covers the right side of urea water tank 25, and rear cover 41B covers the rear side of urea water tank 25. This can prevent the urea water tank 25 from being damaged by collision with the outside.

The upper portion of the supporting frame 30 extends forward and rotatably supports the upper portion of the grain raising portion 8A via the rotation supporting member 31. Further, the lower portion of the support frame 30 extends toward the front side and is coupled to the rear portion of the body frame 1.

The rotating frame 32 extends rightward from a coupling position coupled to a lower portion of the support frame 30 and then forward, and is pivotally supported by a vertical support shaft P at a position outside a rear portion of the body frame 1, and the rotating frame 32 is provided so as to be coupled to and uncoupled from the lower portion of the support frame 30. Thus, the rotating frame 32 can rotate outward of the machine body about the pivot shaft P by releasing the connection with the lower portion of the support frame 30. Further, by coupling the rear end portion of the rotating frame 32 to the support frame 30, the rigidity of the rotating frame 30 is increased, and deformation can be prevented.

The urea water tank 25 is placed on a plate-shaped support base (the "1 st support base" in the claims) 33. The support table 33 is supported at 2 positions in the front-rear direction of the rotating frame 32 via 2 leg portions 34 provided at predetermined intervals in the front-rear direction. Accordingly, by rotating the rotating frame 32 about the support shaft P, the urea water tank 25 and the support base 33 supported by the rotating frame 32 can be rotated outward from the machine body. This makes it possible to easily perform the work of attaching and detaching the raised/lowered part 8A and the maintenance of the urea water tank 25.

The supporting table 33 may be provided at a position higher than the rotary gear 36, the rotary gear 36 may be provided near an upper portion of the communicating portion 35, and the communicating portion 35 may communicate a lower portion of the grain raising portion 8A with the transporting means of the grain bin 7. A turning motor 37 for driving the turning gear 36 is provided above the turning gear 36 so that the longitudinal direction thereof is along the vertical direction.

As shown in fig. 8 and 9, a support member 45 is supported on the right front portion of the support base 33. The support member 45 is formed of: a 1 st extending portion 45A extending upward from the support table 33; and a 2 nd extending portion 45B bent at an upper portion of the 1 st extending portion 45A and extending rearward. This prevents the urea tank 25 from falling from the support base 33, and allows the support member 45 to be easily removed from the support base 33 and the urea tank 25 to be easily removed when the urea tank 25 is removed from the support base 33.

A fixing member 48 is coupled to a rear portion of the 2 nd extending portion 45B of the support member 45 via a coupling plate 44. A support shaft 46A extending in the left-right direction is provided above the fixing member 48, and the support shaft 46A vertically rotatably supports an upper portion of a plate-shaped support base (a "2 nd support base" in the claims) 46. An upper portion of the support member 47 is rotatably supported on a support shaft 46B formed on a right portion of the support base 46 and extending in the left-right direction.

When the urea water is supplied to the urea water tank 25, the support base 46 is rotated upward about the support shaft 46A to be in a horizontal posture, and then a key-shaped end portion bent into a long hole formed in the support member 47 is engaged with a pin 48A provided in the fixing member 48 and extending in the left-right direction. This makes it possible to place a container such as a plastic bag storing urea solution for replenishment or a tank storing a plastic bag on the support base 46, and to easily perform the replenishment operation.

On the other hand, when the supply of the urea solution to the urea water tank 25 has been completed, the key-shaped end portion of the elongated hole of the support member 47 is disengaged from the pin 48A of the fixing member 48, and then the support base 46 is rotated downward about the support shaft 46A. This allows the support stand 46 to be suspended to the rear side of the urea water tank 25 and placed in the storage state.

Next, the switch panel 50 will be explained. As shown in fig. 10, a switch panel 50 is detachably fixed to the left side of the monitor 52 of the front panel 51 of the operation unit 5 and the right front side of the main shift lever 54 of the side panel 53, and a plurality of switches for adjusting the sound volume of the alarm and the tilt angle of the body are provided on the switch panel 50.

As shown in fig. 11, a front hook 55 is provided on the front wall of the switch panel 50. The lower portion of the front hook 55 is fixed to the front wall of the switch panel 50, the upper portion of the front hook 55 is provided at a predetermined interval from the front wall of the switch panel 50 toward the front side, and a front groove 55A is formed in a portion of the upper wall of the switch panel 50 facing the front hook 55.

Also, a rear side hook 56 is provided on the rear wall of the switch panel 50. The lower portion of the rear hook 56 is fixed to the rear wall of the switch panel 50, and the upper portion of the rear hook 56 is provided at a predetermined interval from the rear wall of the switch panel 50 toward the rear side.

Thus, when the switch panel 50 is attached to the front panel 51 or the like, the switch panel 50 can be easily attached to the front panel 51 or the like while the front and rear portions of the upper wall of the switch panel 50 are pressed downward, and when the switch panel 50 is detached from the front panel 51 or the like, the switch panel 50 can be easily detached from the front panel 51 or the like by inserting the straight screwdriver into the front groove 55A and moving the front hook 55 rearward to release the engagement between the front hook 55 and the front panel 51 or the like.

When the number of grain stalks conveyed from the harvesting device 3 to the threshing device 4 is large and the threshing load becomes equal to or greater than a predetermined value, the alarm sounds. In order to stop the alarm, it is necessary to decelerate the traveling speed of the traveling apparatus 2 or to move the main shift lever 54 in the low speed direction.

Next, a method of starting the harvesting maintenance mode in which oil supply to the drive chain of the harvesting apparatus 3, replacement of the raising protrusion, and the like are performed will be described.

As shown in fig. 12, a turning force raising switch 60 for reducing the turning radius of the traveling device 2 is provided at an upper portion on the right side of the grip portion 54A of the main shift lever 54, and a raising speed change switch 61 is provided below the turning force raising switch 60, and the raising speed change switch 61 switches the mode of the raising speed of the raising device 3A of the harvesting device 3. When the raising speed of the raising device 3A is switched to the high-speed mode, the high-speed raising speed switch 61A is pressed, and when the raising speed of the raising device 3A is switched to the low-speed mode, the low-speed raising speed switch 61B is pressed. A threshing depth manual switch 62 is provided on the front surface of the handle portion 54A of the main shift lever 54, and the threshing depth manual switch 62 adjusts the threshing depth of the grain pole fed from the harvesting unit 3 to the threshing unit 4. When the awns of the grain bar are inserted deeply into the threshing device 4, the deep threshing depth manual switch 62A is pressed, and when the awns of the grain bar are inserted shallowly into the threshing device 4, the shallow threshing depth manual switch 62B is pressed.

To start the harvest maintenance mode, it can be performed by pressing the high-speed raising speed change switch 61A for about 2 seconds. Therefore, a starting switch of a harvesting maintenance mode is not required to be additionally arranged, and the number of parts can be saved. In addition, instead of the high-speed raising speed change switch 61A, the low-speed raising speed change switch 61B, the deep threshing depth manual switch 62A, or the shallow threshing depth manual switch 62B may be pressed for a long time to start the harvesting maintenance mode. Further, instead of the long press operation of about 2 seconds, the harvesting maintenance mode may be started by pressing the high-speed raising speed change switch 61A and the like 2 times.

When the harvesting maintenance mode is started, the raising protrusion or the like of the raising device 3A of the harvesting device 3 moves at a prescribed speed. The high-speed raising speed switch 61A is pressed to increase the moving speed of the raising protrusion or the like, and the decelerating raising speed switch 61B is pressed to decelerate the moving speed of the raising protrusion or the like. This makes it possible to increase or decrease the moving speed of the lifting protrusion and the like, thereby efficiently performing maintenance work. Further, instead of the high-speed raising speed change switch 61A, the deep threshing depth manual switch 62A may be pressed to increase the moving speed of the raising projection or the like, and instead of the slow raising speed change switch 61B, the shallow threshing depth manual switch 62B may be pressed to decrease the moving speed of the raising projection or the like.

Next, a method of starting the sensor check mode for checking whether or not there is a disconnection abnormality in the sensor 25B and the like provided in the upper portion of the urea water tank 25 will be described.

To start the sensor check mode, it is possible to perform the high-speed raising operation by pressing the raising speed change switch 61A for about 2 seconds. Therefore, the starting switch of the sensor inspection mode is not required to be additionally arranged, and the number of components can be saved. Further, instead of the high-speed raising speed change switch 61A, the low-speed raising speed change switch 61B, the deep threshing depth manual switch 62A, or the shallow threshing depth manual switch 62B may be pressed for a long time to start the sensor check mode.

Further, instead of the long press operation of about 2 seconds, the sensor check mode may be started by pressing the high speed raising speed change switch 61A or the like 2 times.

Next, the travel device 2 in the case where the turning force increasing switch 60 is pressed will be described. For example, when the traveling device 2 is turned to the right, the crawler belt on the left side of the traveling device 2 is rotated in the forward direction, and the crawler belt on the right side is rotated in the backward direction. This makes it possible to make the turning radius of the traveling apparatus 2 smaller than the turning radius of the crawler belt on the left side of the traveling apparatus 2 in the forward direction and to lock (stop) the crawler belt on the right side. When the traveling device 2 is turned to the right, the crawler on the left side of the traveling device 2 is rotated in the backward direction, and the crawler on the right side is rotated in the forward direction.

Claims

1. A combine harvester, wherein a threshing device (4) for threshing a grain pole is arranged on a machine body frame (1) carrying an engine (E), a grain bin (7) for storing threshed grains is arranged on one side of the left and right sides of the threshing device (4), a winnowing part (8A) of a discharge screw conveyor (8) for discharging the stored grains to the outside is arranged on the rear side of the grain bin (7),

the combine harvester is provided with an exhaust purification device (20) for purifying the exhaust gas of the engine (E),

the exhaust gas purification device (20) is provided with:

an oxidation catalyst (21) that oxidizes unburned gas in exhaust gas discharged from the engine (E); and

an SCR (22) for reducing and purifying nitrogen oxides in the exhaust gas after passing through the oxidation catalyst (21) by ammonia generated from the urea water,

the combine harvester is provided with a urea water tank (25) for storing urea water supplied to the SCR (22),

the urea water tank (25) is arranged at the rear side of the rear wall of the grain bin (7) and at the part outside the machine body of the winnowing part (8A),

a water supply port (25A) of the urea water tank (25) is disposed toward the rear of the machine body.

2. A combine harvester, wherein a threshing device (4) for threshing a grain pole is arranged on a machine body frame (1) carrying an engine (E), a grain bin (7) for storing threshed grains is arranged on one side of the left and right sides of the threshing device (4), a winnowing part (8A) of a discharge screw conveyor (8) for discharging the stored grains to the outside is arranged on the rear side of the grain bin (7),

the exhaust gas purification device (20) is provided with:

a water supply port (25A) of the urea water tank (25) is disposed on the rear side of the trough (8A).

3. A combine harvester according to claim 1 or 2,

the combine is configured to be provided with a 1 st support table (33) for supporting the urea water tank (25), wherein the 1 st support table (33) can move towards the outside of the machine body.

4. A combine harvester according to claim 3,

the combine harvester is provided with a 2 nd support table (46), when the urea water is replenished to the urea water tank (25), the 2 nd support table (46) supports a container storing the urea water for replenishment, and the 2 nd support table (46) is provided to be freely switched between a storage state and a use state.

5. A combine harvester according to claim 4,

the combine harvester is provided with a support member (45) for supporting the outer side part of the urea water tank (25), and the 2 nd support table (46) is installed at the rear part of the support member (45).