JP2022065320A - Construction machine - Google Patents

Abstract

To shield a urea water supply device from the heat generated by an engine and a hydraulic pump.SOLUTION: In a hydraulic excavator 1 comprising: a revolving frame 5; an engine 9; a hydraulic pump 12; an exhaust gas post-processor 20 which includes a urea selective reduction catalyst 30; a post-processor support member 33; a urea water supply device 44; a hydraulic oil tank 38; and a tank cover 15C2, the hydraulic oil tank 38 is provided with a planar right wall plate 41D that faces the tank cover 15C2 with an interval in the left-right direction, the post-processor support member 33 is provided with an overhanging part 35D which overhangs toward a right side frame 5C of the revolving frame 5 to partition between a pump chamber 13 and a tank chamber 42, and the urea water supply device 44 is arranged in an article storage space 43 surrounded by the right wall plate 41D of the hydraulic oil tank 38, the overhanging part 35D of the post-processor support member 33 and the tank cover 15C2.SELECTED DRAWING: Figure 8

Description

The present disclosure relates to, for example, a construction machine such as a hydraulic excavator equipped with an exhaust gas purifying device for purifying nitrogen oxides in an exhaust gas.

A hydraulic excavator that represents a construction machine consists of a self-propelled vehicle body and a work device provided on the front side of the vehicle body. It is composed of an upper swivel body. The upper swing body has a vehicle body frame as a base, a work device is attached to the front side of the vehicle body frame, and a counterweight is attached to the rear side of the vehicle body frame. Further, the vehicle body frame is equipped with an engine as a prime mover, a hydraulic pump driven by the engine, a swivel motor for swiveling an upper swivel body by hydraulic oil (hydraulic oil) from the hydraulic pump, and the like.

The engine is located on the front side of the counterweight and the swivel motor is located on the front side of the engine. A partition member (firewall) is usually provided between the engine and the swivel motor, and by partitioning between the swivel motor and the engine to which hydraulic oil is supplied and discharged, the hydraulic oil adhering to the swivel motor or the like can be removed. It prevents heating by the heat from the engine (see Patent Document 1).

On the other hand, a diesel engine is generally used as an engine of a hydraulic excavator, and this diesel engine emits nitrogen oxides (hereinafter referred to as NOx) together with exhaust gas. Therefore, the hydraulic excavator is provided with an exhaust gas aftertreatment device for purifying the exhaust gas discharged from the engine, and this exhaust gas aftertreatment device uses a urea selective reduction catalyst for removing NOx in the exhaust gas. Includes. The urea selective reduction catalyst decomposes NOx in the exhaust gas into harmless nitrogen gas and water by supplying an aqueous urea solution as a reducing agent. Therefore, the hydraulic excavator is provided with a urea water tank for accommodating urea water as a reducing agent and a urea water supply device for supplying the urea water in the urea water tank to the urea selective reduction catalyst (Patent Documents). 2).

The hydraulic excavator according to Patent Document 2 has a urea water injection control unit that controls the injection amount of urea water with respect to the urea selective reduction catalyst, a NOx sensor that detects the amount of NOx in the exhaust gas, and a urea water injection that outputs a signal from the NOx sensor. It has a NOx controller to supply to the control unit. This hydraulic excavator is provided with a shielding member that shields the NOx controller from the heat generated by the engine or the hydraulic pump.

Japanese Unexamined Patent Publication No. 2012-57590 Japanese Unexamined Patent Publication No. 2017-53315

When the urea water used for purifying NOx is held at a high temperature of about 60 ° C., the quality deteriorates at an early stage and cannot be used, and the higher the temperature, the faster the quality deteriorates. Therefore, the urea water tank for storing urea water is usually arranged in a place where the temperature is kept low and is not easily affected by the heat from the engine and the hydraulic pump. However, the urea water supply device equipped with a urea water pump that supplies urea water in the urea water tank to the urea selective reduction catalyst and a filter that captures foreign substances mixed in the urea water is exposed to heat from the engine or the like. In this case, there is a problem that the quality of the urea water supplied to the urea selective reduction catalyst deteriorates.

An object of the present invention is to provide a construction machine capable of shielding a urea water supply device from heat generated by an engine or a hydraulic pump.

One embodiment of the present invention includes a self-propelled vehicle body and a working device provided on the front side of the vehicle body. The vehicle body has a center frame and left and right side frames, and the working device is attached to the front side. A vehicle body frame, an engine mounted on the rear side of the vehicle body frame, a hydraulic pump arranged on one side of the vehicle body in the left-right direction adjacent to the engine and driven by the engine, and a hydraulic pump. An exhaust gas post-treatment device provided on the upper side and containing a urea selective reduction catalyst for removing nitrogen oxides in the exhaust gas discharged from the engine, and an exhaust gas post-treatment device attached to the vehicle body frame straddling the hydraulic pump. The post-treatment device support member that supports the device, the urea water supply device that supplies urea water that is the reducing agent of the urea selective reduction catalyst to the urea selective reduction catalyst, and the vehicle body frame located in front of the hydraulic pump. In a construction machine including an oil storage tank mounted on the vehicle body frame and a tank cover attached to the vehicle body frame and covering the oil storage tank from the left and right directions of the vehicle body frame.
The oil storage tank is provided with a flat peripheral wall surface having a flat surface facing the tank cover at intervals in the left-right direction, and the aftertreatment device support member is projected toward the side frame of the vehicle body frame and the hydraulic pressure is increased. An overhanging portion is provided between the pump chamber in which the pump is housed and the tank room in which the oil storage tank is housed. It is characterized in that it is arranged in a space surrounded by the overhanging portion of the member and the tank cover.

According to one embodiment of the present invention, the urea water supply device is arranged in a space surrounded by the flat peripheral wall surface of the oil storage tank, the overhanging portion of the post-treatment device support member, and the tank cover. The water supply device can be shielded from the heat generated by the engine, hydraulic pump, and the like. As a result, it is possible to prevent the urea water supplied to the urea selective reduction catalyst through the urea water supply device from being exposed to a high temperature, and to maintain good quality of the urea water.

It is a right side view which shows the hydraulic excavator to which the embodiment of this invention is applied. It is a top view of a hydraulic excavator. It is a top view which shows the state which the engine, the hydraulic pump, the hydraulic oil tank, etc. are mounted on the swivel frame. It is a top view which shows the state which the engine, the exhaust gas aftertreatment device, the hydraulic oil tank, etc. are mounted on the swivel frame. It is a perspective view which shows the swivel frame, the exhaust gas aftertreatment device, the aftertreatment device support member, the hydraulic oil tank, the urea water supply device and the like. It is an exploded perspective view which shows the post-processing apparatus support member and the block plate. It is a perspective view which shows the state which attached the block plate to the post-processing apparatus support member. It is sectional drawing which saw the swivel frame, the post-treatment device support member, the hydraulic oil tank, the tank cover, etc. from the direction of arrow VIII-VIII in FIG. It is a block diagram which shows schematic the exhaust gas aftertreatment device.

Hereinafter, a case where the construction machine according to the embodiment of the present invention is applied to a hydraulic excavator will be described in detail with reference to FIGS. 1 to 9. In the embodiment, the traveling direction of the hydraulic excavator is defined as the front-rear direction, and the direction orthogonal to the traveling direction of the hydraulic excavator is defined as the left-right direction.

The crawler-type hydraulic excavator 1 representing a construction machine includes a self-propelled crawler-type lower traveling body 2 and an upper turning body 3 mounted on the lower traveling body 2 so as to be able to turn, and these lower traveling bodies are provided. The vehicle body is composed of 2 and the upper swivel body 3. A work device 4 is provided on the front side of the upper swivel body 3, and the hydraulic excavator 1 performs excavation work of earth and sand by moving the work device 4 up and down while swiveling the upper swivel body 3.

The upper swivel body 3 has a swivel frame 5 as a vehicle body frame, and the swivel frame 5 is mounted on the lower traveling body 2 so as to be swivelable. A work device 4 is attached to the front end side of the swivel frame 5, and a counterweight 6 for balancing the weight with the work device 4 is provided on the rear end side of the swivel frame 5. A cab 7 on which an operator rides is provided on the left side of the front part of the swivel frame 5, and an article storage 8 having a stepped boarding / alighting step formed on the upper surface thereof is provided on the right side of the front part of the swivel frame 5. .. Further, the swivel frame 5 is located in front of the counter weight 6 and has an engine 9, a hydraulic pump 12, an exhaust gas aftertreatment device 20, a posttreatment device support member 33, a hydraulic oil tank 38, and a urea water supply device, which will be described later. 44 etc. are installed.

As shown in FIGS. 3 to 5, the swivel frame 5 includes a center frame 5A arranged at the center in the left-right direction and extending in the front-rear direction, and a left side frame 5B arranged on the left side of the center frame 5A and extending in the front-rear direction. It is roughly configured by a right side frame 5C arranged on the right side of the center frame 5A and extending in the front-rear direction. The center frame 5A includes a bottom plate 5D made of a thick steel plate or the like, and a left vertical plate 5E and a right vertical plate 5F that are erected on the bottom plate 5D and extend in the front-rear direction while facing each other in the left-right direction. There is.

Between the center frame 5A and the left side frame 5B, a plurality of left overhang beams 5G extending in the left-right direction are provided at intervals in the front-rear direction. The left side frame 5B is attached to the left side of the center frame 5A via the plurality of left overhang beams 5G. On the other hand, between the center frame 5A and the right side frame 5C, a plurality of right overhang beams 5H extending in the left-right direction are provided at intervals in the front-rear direction. The right side frame 5C is attached to the right side of the center frame 5A via the plurality of right overhang beams 5H.

A rear support leg 34 of a post-processing device support member 33, which will be described later, is attached to the right overhang beam 5H1 arranged on the rearmost side of the plurality of right overhang beams 5H. Further, the front support legs 35 of the post-processing device support member 33, which will be described later, are attached to the right overhang beam 5H2 arranged on the front side of the right overhang beam 5H1. Further, a hydraulic oil tank 38, which will be described later, is attached to the right overhang beams 5H3 and 5H4 arranged on the front side of the right overhang beam 5H2.

The engine 9 is located on the front side of the counterweight 6 and is provided on the rear side of the turning frame 5. The engine 9 is elastically supported by the swivel frame 5 via a vibration-proof member (not shown). The engine 9 is composed of a diesel engine, and is mounted on the turning frame 5 in a horizontally placed state in which a crank shaft (not shown) extends in the left-right direction. The engine 9 is provided with a cooling fan 9A that is rotationally driven by the engine 9.

A firewall 10 extending in the left-right direction is provided on the front side of the engine 9. The firewall 10 partitions between the engine 9, which becomes hot during operation, and hydraulic equipment (not shown) such as a swivel motor and a control valve. As a result, an engine chamber 11 covered with a building cover 15, which will be described later, is formed between the firewall 10 and the counterweight 6, and the engine 9 is housed in the engine chamber 11.

The hydraulic pump 12 is provided adjacent to the engine 9 on one side (right side) in the left-right direction of the swivel frame 5. The hydraulic pump 12 is driven by the engine 9 to discharge pressure oil for operation toward various hydraulic devices mounted on the hydraulic excavator 1. An exhaust gas aftertreatment device 20 is arranged above the hydraulic pump 12. Here, at the boundary between the engine 9 and the hydraulic pump 12, a partition member (not shown) that shields the hydraulic pump 12 from the heat generated by the engine 9 is provided. As a result, a pump chamber 13 isolated from the engine chamber 11 is formed on the right side of the engine 9, and the hydraulic pump 12 is housed in the pump chamber 13.

The heat exchanger 14 is provided adjacent to the engine 9 on the other side (left side) of the turning frame 5 in the left-right direction. The heat exchanger 14 includes a radiator for cooling engine cooling water, an oil cooler for cooling hydraulic oil, and the like. The cooling fan 9A sucks outside air into the building cover 15 by being rotationally driven by the engine 9, and supplies this outside air to the heat exchanger 14 as cooling air. The heat exchanger 14 cools the engine cooling water, the hydraulic oil, and the like by the supplied cooling air.

The building cover 15 is located on the front side of the counterweight 6 and is provided on the swivel frame 5. Inside the building cover 15, the engine 9, the hydraulic pump 12, the heat exchanger 14, and the like are mounted on the swivel frame 5. Contains various on-board equipment. The building cover 15 includes a top cover 15A that covers the mounted equipment from above, a left side cover 15B that covers the mounted equipment from the left side, and a right side cover 15C that covers the mounted equipment from the right side. (Not shown) is supported on the swivel frame 5.

An engine cover 16, a heat exchanger cover 17, and an aftertreatment device cover 18 are provided adjacent to each other in the left-right direction on the upper side of the top cover 15A. The engine cover 16 is formed in a box shape that rises upward from the upper surface cover 15A, and covers the inspection opening (not shown) formed in the upper surface cover 15A so as to be openable and closable in order to perform inspection work of the engine 9 and the like. There is. The heat exchanger cover 17 is arranged on the left side of the engine cover 16 and covers the upper part of the heat exchanger 14 projecting onto the upper surface cover 15A through the inspection opening. The aftertreatment device cover 18 is arranged on the right side of the engine cover 16 and covers the exhaust gas aftertreatment device 20, which will be described later, so as to be openable and closable.

The left side cover 15B is arranged between the left end of the top cover 15A and the left side frame 5B of the swivel frame 5, and extends from the left end of the counterweight 6 to the rear end of the cab 7. The left side cover 15B faces the heat exchanger 14 in the left-right direction, and covers the heat exchanger 14 and the like so as to be openable and closable from the left side.

The right side cover 15C is arranged between the right end of the top cover 15A and the right side frame 5C of the swivel frame 5, and extends from the right end of the counterweight 6 to the rear end of the article storage 8. The right side cover 15C is composed of, for example, a rear cover 15C1, a tank cover 15C2, and a front cover 15C3, and the outer surfaces (right surface) of the rear cover 15C1, the tank cover 15C2, and the front cover 15C3 form the same plane. are doing.

Here, the rear cover 15C1 faces the hydraulic pump 12 in the left-right direction and covers the hydraulic pump 12 so as to be openable and closable from the right side. The tank cover 15C2 is arranged adjacent to the front side of the rear cover 15C1. The tank cover 15C2 covers the hydraulic oil tank 38 so as to be openable and closable from the right side. The front cover 15C3 is arranged adjacent to the front side of the tank cover 15C2. The front cover 15C3 covers the fuel tank 19 arranged on the front side of the hydraulic oil tank 38 for storing fuel from the right side.

The exhaust gas aftertreatment device 20 is provided on the upper side of the hydraulic pump 12 in a state of being supported by the aftertreatment device support member 33. The exhaust gas aftertreatment device 20 is connected to the engine 9 via the exhaust pipe 21 and treats harmful substances contained in the exhaust gas from the engine 9. The exhaust gas aftertreatment device 20 includes, for example, as shown in FIG. 9, a first aftertreatment device 22 and a second aftertreatment device 28.

The first post-processing device 22 includes a cylindrical body 23 extending in the front-rear direction. The tubular body 23 is formed as a closed container with both ends closed, an inflow port 23A is provided on the upstream side of the tubular body 23, and the tip of the exhaust pipe 21 is connected to the inflow port 23A. An oxidation catalyst 24 is disposed in the cylinder 23. The oxidation catalyst 24 is made of, for example, a ceramic cell-shaped cylinder, and a large number of through holes are formed in the axial direction thereof, and the inner surface thereof is coated with a precious metal or the like. The oxidation catalyst 24 oxidizes and removes carbon monoxide (CO), hydrocarbons (HC) and the like contained in the exhaust gas by passing the exhaust gas through the through holes under a predetermined temperature. Further, the oxidation catalyst 24 burns and removes particulate matter (PM) as needed.

The connection pipe 25 connects between the first post-processing device 22 and the second post-processing device 28. The inlet side of the connecting pipe 25 is connected to the tubular body 23 of the first aftertreatment device 22, and a urea water injection valve 26 is attached to an intermediate portion of the connecting pipe 25. The urea water injection valve 26 is connected to, for example, a urea water tank (not shown) arranged in the article storage 8 via a urea water pipeline 27, and supplies urea water supplied by a urea water supply device 44 described later. , Is injected toward the exhaust gas circulating in the connecting pipe 25.

The second aftertreatment device 28 is connected to the outlet side of the connecting pipe 25. The second aftertreatment device 28 includes a cylindrical cylinder 29 extending in the front and rear directions in parallel with the cylinder 23 of the first aftertreatment device 22. The tubular body 29 is formed as a closed container with both ends closed, and a urea selective reduction catalyst 30 and an oxidation catalyst 31 are provided in the tubular body 29.

The urea selective reduction catalyst 30 is made of, for example, a ceramic cell-shaped cylinder, and has a large number of through holes formed in the axial direction thereof, and the inner surface thereof is coated with a precious metal. The urea selective reduction catalyst 30 selectively reduces nitrogen oxides (NOx) contained in the exhaust gas discharged from the engine 9 with ammonia in the urea aqueous solution injected from the urea water injection valve 26, and causes a reduction reaction with nitrogen. Decomposes into water. Like the oxidation catalyst 24 of the first post-treatment device 22, the oxidation catalyst 31 is made of a cell-shaped cylinder made of ceramics, and a large number of through holes are formed in the axial direction thereof, and the inner surface thereof is coated with a precious metal. There is. As a result, the oxidation catalyst 31 oxidizes the ammonia remaining after the urea selective reduction catalyst 30 reduces the nitrogen oxide, and separates it into nitrogen and water.

The tail tube 32 is provided in a rear portion on the downstream side of the tubular body 29, the lower end side is inserted into the tubular body 29, and the upper end protrudes upward from the tubular body 29. Therefore, the exhaust gas discharged from the engine 9 is introduced into the exhaust gas aftertreatment device 20 through the exhaust pipe 21, purified by the exhaust gas aftertreatment device 20, and then discharged to the outside through the tail pipe 32. ..

Next, the aftertreatment device support member 33 that supports the exhaust gas aftertreatment device 20 on the swivel frame 5 will be described.

The aftertreatment device support member 33 straddles the hydraulic pump 12 from above and is attached to the swivel frame 5, and supports the exhaust gas aftertreatment device 20 on the upper side of the hydraulic pump 12. As shown in FIGS. 5 to 8, the post-processing device support member 33 includes a rear support leg 34, a front support leg 35, and a gantry 37.

The rear support leg 34 is attached to the rearmost right overhang beam 5H1 of the right overhang beam 5H constituting the swivel frame 5. The rear support legs 34 include a lower plate 34A that abuts on the upper surface of the right overhang beam 5H1, a rear vertical plate 34B that extends upward from the lower plate 34A, and an upper plate 34C that is fixed to the upper end of the rear vertical plate 34B. Have. The rear vertical plate 34B is formed by using, for example, a groove-shaped steel having a U-shaped cross-sectional shape. The rear support legs 34 are attached to the swivel frame 5 in a state of being arranged behind the hydraulic pump 12 by fixing the lower plate 34A to the right overhang beam 5H1 using bolts.

The front support leg 35 is attached to the right overhang beam 5H2 arranged on the front side of the right overhang beam 5H1 and is paired with the rear support leg 34 in the front-rear direction. The front support leg 35 includes a lower plate 35A that abuts on the upper surface of the right overhang beam 5H2, a front vertical plate 35B that extends upward from the lower plate 35A, and an upper plate 35C that is fixed to the upper end of the front vertical plate 35B. Have. The front vertical plate 35B is formed by using, for example, a groove-shaped steel having a U-shaped cross-sectional shape. The front support legs 35 are attached to the swivel frame 5 in a state of being arranged on the front side of the hydraulic pump 12 by fixing the lower plate 35A to the right overhang beam 5H2 using bolts.

As shown in FIG. 7, the width dimension A in the left-right direction of the front vertical plate 35B constituting the front support leg 35 is set to be larger than the width dimension B in the left-right direction of the rear vertical plate 34B constituting the rear support leg 34. (A> B). Then, with the lower plate 35A of the front support leg 35 fixed to the right overhang beam 5H2, the left end portion 35B1 side of the front vertical plate 35B faces the rear vertical plate 34B of the rear support leg 34 in the front-rear direction, and is in the front vertical direction. The right end portion 35B2 of the plate 35B extends to the right side frame 5C side of the rear vertical plate 34B (see FIG. 8).

In this way, the right end portion 35B2 of the front vertical plate 35B extends to a position adjacent to the right side frame 5C, so that the right end portion 35B2 side of the front vertical plate 35B is the right wall plate of the hydraulic oil tank 38, which will be described later. It is an overhanging portion 35D that overhangs to the right side of 41D. Here, in the front vertical plate 35B formed to be wider than the rear vertical plate 34B, a notch 35E notched in an arc shape from the left end portion 35B1 to the right end portion 35B2 is formed for the purpose of weight reduction and the like. ing. The overhanging portion 35D of the front vertical plate 35B is provided with a plurality of (for example, two) bolt holes 35F using back nuts on the peripheral edge portion of the notch portion 35E.

The block plate 36 is attached to the front vertical plate 35B. The closing plate 36 is made of a flat plate, and is detachably fixed to the front vertical plate 35B by two bolts 36A screwed into the bolt holes 35F of the front vertical plate 35B to close the notch 35E. As a result, with the aftertreatment device support member 33 and the hydraulic oil tank 38 attached to the swivel frame 5, the overhanging portion 35D of the front vertical plate 35B partitions between the tank chamber 42 and the pump chamber 13, which will be described later. It has become.

The gantry 37 is attached to the upper plate 34C of the rear support leg 34 and the upper plate 35C of the front support leg 35. The gantry 37 extends in the front-rear direction between the rear support legs 34 and the front support legs 35 straddling the upper side of the hydraulic pump 12, and supports the exhaust gas aftertreatment device 20 on the upper side of the hydraulic pump 12. The gantry 37 has a rear surface plate 37A erected on the upper side of the rear support legs 34, a front plate 37B erected on the upper side of the front support legs 35, and the rear surface plate 37A and the front plate 37B in the front-rear direction. It is roughly configured by an extended mounting pedestal 37C.

A lower plate 37A1 is provided at the lower end of the rear surface plate 37A, and the lower plate 37A1 is fixed to the upper plate 34C of the rear support leg 34 by using bolts. A lower plate 37B1 is provided at the lower end of the front plate 37B, and the lower plate 37B1 is fixed to the upper plate 35C of the front support leg 35 by using bolts. The mounting pedestal 37C has a square cylindrical upper pedestal 37C1 extending in the front-rear direction and a flat plate-shaped lower pedestal 37C2 arranged at a position lower than the upper surface of the upper pedestal 37C1. The rear end of the mounting pedestal 37C is fixed to the rear surface plate 37A by means such as welding, and the front end of the mounting pedestal 37C is fixed to the front plate 37B by means such as welding.

A first aftertreatment device 22 constituting the exhaust gas aftertreatment device 20 is attached to the lower pedestal 37C2 of the mounting pedestal 37C, and a second aftertreatment device 28 is attached to the upper pedestal 37C1. As a result, the exhaust gas aftertreatment device 20 is arranged above the hydraulic pump 12 in a state of being supported by the aftertreatment device support member 33.

The hydraulic oil tank 38 as an oil storage tank is located on the front side of the hydraulic pump 12 and between the right vertical plate 5F and the tank cover 15C2 and is mounted on the swivel frame 5. The hydraulic oil tank 38 is arranged adjacent to each other between the fuel tank 19 and the front support legs 35 of the aftertreatment device support member 33, and supplies hydraulic oil to various hydraulic actuators mounted on the hydraulic excavator 1. It is stored. The hydraulic oil tank 38 is mounted between the right vertical plate 5F and the right side frame 5C of the swivel frame 5 on two right overhang beams 5H3, 5H4 out of a plurality of right overhang beams 5H.

As shown in FIGS. 5 and 8, the hydraulic oil tank 38 serves as a peripheral wall surface connecting the bottom plate 39 and the upper plate 40 as the bottom surface and the upper surface facing each other in the vertical direction and between the bottom plate 39 and the upper plate 40. It is configured to include the peripheral wall plate 41 of the above. The bottom plate 39 is formed as a flat plate having a polygonal shape (a pentagonal shape with chamfered corners on the left rear side of a rectangle) extending in the front-rear direction, and is mounted on the right overhang beams 5H3 and 5H4 using bolts or the like. The upper plate 40 is formed as a rectangular flat plate extending in the front-rear direction, and faces the bottom plate 39 at intervals. The upper plate 40 and the upper surface cover 15A of the building cover 15 form the same plane.

The peripheral wall plate 41 is formed in a square cylinder shape having a polygonal (for example, hexagonal) cross-sectional shape. Specifically, the peripheral wall plate 41 includes a front wall plate 41A and a rear wall plate 41B extending in the left-right direction while facing each other in the front-rear direction, and a left wall plate 41C and a right wall plate 41D extending in the front-rear direction while facing each other in the left-right direction. It is composed of a hexahedron surrounded by six flat surfaces of inclined wall plates 41E and 41F having two inclined surfaces arranged at a corner where the rear wall plate 41B and the left wall plate 41C intersect. Here, the front wall plate 41A faces the fuel tank 19 at a slight distance, and the rear wall plate 41B faces the front support leg 35 (front vertical plate 35B) of the post-treatment device support member 33 at a short distance. ing. Further, the left wall plate 41C faces the right vertical plate 5F of the swivel frame 5 with a slight gap.

By arranging the hydraulic oil tank 38 on the right vertical plate 5F side of the swivel frame 5 in this way, the right wall plate 41D of the hydraulic oil tank 38 is left and right with the tank cover 15C2 constituting the building cover 15. They face each other with a large interval in the direction. That is, in the present embodiment, the right wall plate 41D of the hydraulic oil tank 38 (peripheral wall plate 41) constitutes a flat peripheral wall surface. As a result, a tank chamber 42 partitioned from the pump chamber 13 by the overhanging portion 35D of the aftertreatment device support member 33 (front support leg 35) is formed in the building cover 15, and the hydraulic oil tank 38 is formed in the tank chamber 42. Is housed.

The tank chamber 42 is formed as a substantially rectangular parallelepiped space surrounded by the right vertical plate 5F of the swivel frame 5, the tank cover 15C2, the fuel tank 19, and the front support legs 35 of the aftertreatment device support member 33. .. Since the hydraulic oil tank 38 is housed in the tank chamber 42 in a state of being offset to the right vertical plate 5F, the right wall plate 41D of the hydraulic oil tank 38 and the aftertreatment device support member 33 are housed in the tank chamber 42. An article storage space 43 surrounded by an overhanging portion 35D (front support leg 35) and a tank cover 15C2 is formed.

Here, if the hydraulic oil tank has a cylindrical peripheral wall plate, a plurality of spaces dispersed at the four corners of the tank chamber 42 are formed between the cylindrical peripheral wall plate and the tank chamber 42. The accommodation space of each space is reduced. On the other hand, in the present embodiment, the hydraulic oil tank 38 is provided with a right wall plate 41D which is a flat peripheral wall surface facing the tank cover 15C2 in the left-right direction, and is provided between the right wall plate 41D and the tank cover 15C2. One article storage space 43 corresponding to the length dimension in the front-rear direction of the hydraulic oil tank 38 is formed. As a result, an article storage space 43 having a large storage space can be formed between the hydraulic oil tank 38 and the tank cover 15C2 while sufficiently securing the capacity of the hydraulic oil tank 38.

The urea water supply device 44 is located in the article storage space 43 and is attached to the right wall plate 41D of the hydraulic oil tank 38. The urea water supply device 44 includes a urea water pump that supplies urea water to the urea water injection valve 26, and a urea water filter that captures foreign substances mixed in the urea water. The urea water supply device 44 is a urea water pipeline that connects a urea water tank (not shown) arranged in the article storage 8 and a urea water injection valve 26 attached to the exhaust gas aftertreatment device 20. Urea water, which is a reducing agent provided in the middle of 27 and stored in the urea water tank, is supplied toward the urea water injection valve 26.

As shown in FIG. 5, the urea water supply device 44 is fixed to the right wall plate 41D of the hydraulic oil tank 38. As a result, the urea water supply device 44 is stably held in the article storage space 43. Here, when the engine 9 operates and the cooling fan 9A rotates, the outside air (cooling air) sucked into the building cover 15 is supplied to the heat exchanger 14, and then toward the hydraulic pump 12 side along the engine 9. Flows. As shown in FIG. 8, a part of this cooling air is a flow of cooling air F1 that tries to flow into the tank chamber 42 from the engine chamber 11 and a flow of cooling air that tries to flow into the tank chamber 42 from the pump chamber 13. Generate F2 and. In this case, the cooling air flow F1 is blocked from flowing into the tank chamber 42 by the hydraulic oil tank 38, and the cooling air flow F2 is provided by the hydraulic oil tank 38 and the overhanging portion 35D of the aftertreatment device support member 33. The inflow to the tank chamber 42 is blocked.

Therefore, even if the engine 9 and the hydraulic pump 12 generate heat when the hydraulic excavator 1 is operated, the hot air from the engine 9 and the hydraulic pump 12 flows into the article accommodating space 43 formed in the tank chamber 42. Can be blocked. As a result, the urea water supply device 44 arranged in the article storage space 43 can be shielded from the heat generated by the engine 9 and the hydraulic pump 12, and is supplied from the urea water supply device 44 to the urea water injection valve 26. The structure is such that the deterioration of the quality of urea water can be suppressed.

The upper plate 40 of the hydraulic oil tank 38 is provided with a top cover 45 as a cover member. The upper surface cover 45 is formed of a rectangular flat plate having a length dimension substantially equal to the length dimension in the front-rear direction of the upper plate 40, and is fixed to the upper plate 40 by means such as welding. The upper surface cover 45 projects to the right from the right wall plate 41D of the peripheral wall plate 41 constituting the hydraulic oil tank 38, and extends to the upper end portion of the tank cover 15C2. As a result, the upper surface cover 45 covers the urea water supply device 44 attached to the right wall plate 41D from above, and also shields the urea water supply device 44 from the heat generated by the exhaust gas aftertreatment device 20.

The hydraulic excavator 1 according to the present embodiment has the above-mentioned configuration, and its operation will be described below.

The hydraulic pump 12 is driven by the operator on the cab 7 operating the engine 9. The pressure oil from the hydraulic pump 12 is supplied to various hydraulic actuators of the hydraulic excavator 1 via a control valve (not shown). In this state, the operator can operate the traveling operation lever to move the lower traveling body 2 forward or backward. Further, by operating the operation lever for work, the operator can perform excavation work of earth and sand using the work device 4 while turning the upper swivel body 3.

When the hydraulic excavator 1 is in operation, the oxidation catalyst 24 provided in the first aftertreatment device 22 constituting the exhaust gas aftertreatment device 20 is carbon monoxide (CO) and hydrocarbons in the exhaust gas discharged from the engine 9. Hydrogen (HC) and the like are oxidized and removed. On the other hand, the urea selective reduction catalyst 30 provided in the second post-treatment device 28 makes nitrogen oxides (NOx) in the exhaust gas harmless by injecting urea water from the urea water injection valve 26. And decomposes into water. Further, the oxidation catalyst 31 provided in the second post-treatment device 28 oxidizes and removes the residual ammonia. In this way, the exhaust gas discharged from the engine 9 is purified by the exhaust gas aftertreatment device 20 and then discharged into the atmosphere through the tail pipe 32.

Here, in the present embodiment, the upper swivel body 3 of the hydraulic excavator 1 has a right wall plate 41D provided in the hydraulic oil tank 38 and an overhanging portion 35D provided in the front support leg 35 of the aftertreatment device support member 33. And the article storage space 43 surrounded by the tank cover 15C2 are formed. Then, in the article accommodating space 43, the urea water supply device 44 that supplies urea water to the urea water injection valve 26 is accommodated in a state of being fixed to the right wall plate 41D of the hydraulic oil tank 38.

When the engine 9 is operating, outside air (cooling air) is sucked into the building cover 15 by the cooling fan 9A, and this cooling air is supplied to the heat exchanger 14 and then to the hydraulic pump 12 side along the engine 9. It flows. A part of this cooling air generates a cooling air flow F1 that tries to flow into the tank chamber 42 from the engine chamber 11 and a cooling air flow F2 that tries to flow into the tank chamber 42 from the pump chamber 13 (FIG. 8). However, the flow F1 of the cooling air is blocked from flowing into the tank chamber 42 by the hydraulic oil tank 38, and the flow F2 of the cooling air is tanked by the hydraulic oil tank 38 and the overhanging portion 35D of the aftertreatment device support member 33. The inflow to the room 42 is blocked.

Therefore, even if the engine 9 and the hydraulic pump 12 generate heat when the hydraulic excavator 1 is operated, the hot air from the engine 9 and the hydraulic pump 12 flows into the article accommodating space 43 formed in the tank chamber 42. Can be blocked. As a result, the urea water supply device 44 arranged in the article accommodating space 43 can be shielded from the heat generated by the engine 9 and the hydraulic pump 12, and the urea water supply device 44 can be used by the engine 9 and the hydraulic pump 12. It is possible to prevent exposure to the generated heat. As a result, the temperature rise of the urea water supplied from the urea water supply device 44 to the urea water injection valve 26 can be suppressed, and the quality of the urea water can be maintained appropriately.

Further, the upper plate 40 of the hydraulic oil tank 38 is provided with a top cover 45. The top cover 45 projects to the right from the right wall plate 41D of the hydraulic oil tank 38 and extends to the upper end of the tank cover 15C2. As a result, the urea water supply device 44 attached to the right wall plate 41D of the hydraulic oil tank 38 can be covered from above by the upper surface cover 45. Therefore, the urea water supply device 44 can be shielded from the heat generated by the exhaust gas aftertreatment device 20, and the temperature rise of the urea water supplied to the urea water injection valve 26 can be suppressed.

Thus, in the embodiment, the swivel frame 5, the engine 9, the hydraulic pump 12, the exhaust gas aftertreatment device 20 including the urea selective reduction catalyst 30, the posttreatment device support member 33, the urea water supply device 44, and the like. In the hydraulic excavator 1 including the hydraulic oil tank 38 and the tank cover 15C2, the hydraulic oil tank 38 is provided with a flat right wall plate 41D facing the tank cover 15C2 at intervals in the left-right direction, and supports the post-treatment device. The member 33 is provided with an overhanging portion 35D that overhangs toward the right side frame 5C of the swivel frame 5 and partitions between the pump chamber 13 in which the hydraulic pump 12 is housed and the tank room 42 in which the hydraulic oil tank 38 is housed. The urea water supply device 44 is arranged in the article storage space 43 surrounded by the right wall plate 41D of the hydraulic oil tank 38, the overhanging portion 35D of the aftertreatment device support member 33, and the tank cover 15C2.

According to this configuration, the urea water supply device 44 can be shielded from the heat generated by the engine 9, the hydraulic pump 12, and the like. As a result, it is possible to prevent the urea water supplied from the urea water injection valve 26 to the urea selective reduction catalyst 30 from being exposed to a high temperature by the urea water supply device 44, and it is possible to maintain good quality of the urea water. ..

In the embodiment, the hydraulic oil tank 38 has a polygonal cross-sectional shape including a bottom plate 39 and an upper plate 40 facing in the vertical direction and a right wall plate 41D, and is a peripheral wall connecting between the bottom plate 39 and the upper plate 40. The swivel frame 5 includes a plate 41, and the swivel frame 5 is provided with a left vertical plate 5E and a right vertical plate 5F that are erected on the center frame 5A and extend in the front-rear direction. Arranged adjacent to the right vertical plate 5F between the right vertical plate 5F and the tank cover 15C2, the urea water supply device 44 is attached to the right wall plate 41D of the hydraulic oil tank 38. According to this configuration, an article storage space 43 having a large storage space can be formed between the right wall plate 41D of the hydraulic oil tank 38 and the tank cover 15C2. Further, by mounting the urea water supply device 44 using the right wall plate 41D of the hydraulic oil tank 38, urea is contained in the article storage space 43 without using a dedicated member for mounting the urea water supply device 44. The water supply device 44 can be stably held.

In the embodiment, the upper plate 40 of the hydraulic oil tank 38 is provided with an upper surface cover 45 that projects from the right wall plate 41D toward the tank cover 15C2 and covers the urea water supply device 44 from above. According to this configuration, by covering the urea water supply device 44 from above with the top cover 45, the urea water supply device 44 can be shielded from the heat generated by the exhaust gas aftertreatment device 20.

In the embodiment, the hydraulic oil tank 38 is exemplified as an oil storage tank that forms an article accommodating space 43 with the tank cover 15C2. However, the present invention is not limited to this, and for example, the fuel tank may be arranged at a position facing the tank cover, and an article storage space may be formed between the fuel tank and the tank cover.

Further, in the embodiment, as an oil storage tank having a flat peripheral wall surface, a hydraulic oil tank 38 provided with a peripheral wall plate 41 having a polygonal (hexagonal) cross-sectional shape is exemplified. However, the present invention is not limited to this, and for example, an oil storage tank provided with a flat peripheral wall surface having a semi-elliptical cross-sectional shape obtained by cutting an ellipse at a major axis portion may be used.

Further, in the embodiment, the hydraulic excavator 1 provided with the crawler type lower traveling body 2 as a construction machine has been described as an example. However, the present invention is not limited to this, and may be applied to, for example, a hydraulic excavator provided with a wheel-type lower traveling body, and can be widely applied to other construction machines such as hydraulic cranes.

2 Lower running body (body)
3 Upper swivel body (body)
4 Work equipment 5 Swivel frame (body frame)
5A Center frame 5B Left side frame 5C Right side frame 5F Right vertical plate (vertical plate)
9 Engine 12 Hydraulic pump 13 Pump room 15C Right side cover 15C2 Tank cover 20 Exhaust gas aftertreatment device 30 Urea selective reduction catalyst 33 Posttreatment device support member 35 Front support leg 35D Overhanging part 38 Hydraulic oil tank (oil storage tank)
39 Bottom plate 40 Top plate 41 Peripheral wall plate (peripheral wall surface)
41D right wall plate (flat peripheral wall surface)
42 Tank room 43 Goods storage space (space)
44 Urea water supply device 45 Top cover (cover member)

Claims (3)

It is equipped with a self-propelled vehicle body and a work device provided on the front side of the vehicle body.
The vehicle body has a center frame and left and right side frames, and the vehicle body frame to which the work device is attached to the front side.
The engine mounted on the rear side of the vehicle body frame and
A hydraulic pump located on one side of the vehicle body in the left-right direction adjacent to the engine and driven by the engine.
An exhaust gas aftertreatment device provided above the hydraulic pump and containing a urea selective reduction catalyst for removing nitrogen oxides in the exhaust gas discharged from the engine.
A post-treatment device support member that is attached to the vehicle body frame across the hydraulic pump and supports the exhaust gas after-treatment device.
A urea water supply device that supplies urea water, which is a reducing agent for the urea selective reduction catalyst, to the urea selective reduction catalyst.
An oil storage tank located on the front side of the hydraulic pump and mounted on the vehicle body frame,
In a construction machine including a tank cover attached to the vehicle body frame and covering the oil storage tank from the left-right direction of the vehicle body frame.
The oil storage tank is provided with a flat peripheral wall surface having a flat surface facing the tank cover at intervals in the left-right direction.
The aftertreatment device support member is provided with an overhanging portion that extends toward the side frame of the vehicle body frame and partitions between a pump chamber in which the hydraulic pump is housed and a tank room in which the oil storage tank is housed. ,
The urea water supply device is a construction machine characterized in that it is arranged in a space surrounded by the flat peripheral wall surface of the oil storage tank, the overhanging portion of the aftertreatment device support member, and the tank cover. The oil storage tank is configured to include a bottom surface and an upper surface facing each other in the vertical direction, and a peripheral wall surface having a polygonal cross-sectional shape including the flat peripheral wall surface and connecting between the bottom surface and the upper surface surface.
The vehicle body frame is provided with a vertical plate that stands on the center frame and extends in the front-rear direction.
The oil storage tank is arranged adjacent to the vertical plate between the vertical plate of the vehicle body frame and the tank cover.
The construction machine according to claim 1, wherein the urea water supply device is attached to the flat peripheral wall surface of the oil storage tank. The invention according to claim 1 or 2, wherein the upper surface of the oil storage tank is provided with a cover member that projects from the flat peripheral wall surface toward the tank cover and covers the urea water supply device from above. Construction machinery.

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