Operating machinery

Abstract

The present invention provides a work machine capable of appropriately arranging a plurality of exhaust treatment devices. The work machine comprises: an engine (7); a first exhaust treatment device (12) for treating exhaust gas discharged from the engine (7); and a second exhaust treatment device (14) for treating exhaust gas after passing through the first exhaust treatment device (12). The longitudinal direction of the first exhaust treatment device (12) is inclined relative to the front-rear direction (X) and the left-right direction (Y), and is inclined relative to the longitudinal direction of the second exhaust treatment device (14).

Description

Technical Field

[0001] The present disclosure relates to a working machine. Background Art

[0002] International Publication No. 2016 / 002973 (Patent Document 1) discloses a rear-mounted ultra-small swing-type hydraulic excavator equipped with an exhaust gas treatment unit having a diesel particulate filter device and a selective catalyst reduction device.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2016 / 002973 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In a work machine equipped with a plurality of exhaust gas treatment devices in order to comply with exhaust gas regulations, it is necessary to appropriately arrange the plurality of exhaust gas treatment devices on a vehicle body frame having a limited area.

[0008] The present disclosure proposes a work machine capable of appropriately arranging a plurality of exhaust treatment devices.

[0009] Means for solving problems

[0010] According to the present disclosure, a work machine is provided, comprising: an engine; a first exhaust treatment device for treating exhaust gas discharged from the engine; and a second exhaust treatment device for treating exhaust gas after passing through the first exhaust treatment device. The longitudinal direction of the first exhaust treatment device is inclined relative to the front-to-back direction and the left-to-right direction, and is inclined relative to the longitudinal direction of the second exhaust treatment device.

[0011] Effects of the Invention

[0012] According to the working machine of the present disclosure, a plurality of exhaust treatment devices can be appropriately arranged. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a left side view schematically showing the structure of the hydraulic excavator according to the embodiment.

[0014] Figure 2 It is enlarged to show Figure 1 A top view of the right rear portion of the hydraulic excavator's body is shown.

[0015] Figure 3 It is from Figure 2 The rear view of the right rear part of the hydraulic excavator body is viewed in the direction of arrow III.

[0016] Figure 4 It is from Figure 2 A right side view of the right rear portion of the hydraulic excavator body viewed in the direction of arrow IV shown.

[0017] Figure 5 This is a top view of the right rear portion of the hydraulic excavator's body with the engine hood and exhaust treatment cover removed.

[0018] Figure 6 It is from Figure 5 The rear view of the right rear part of the hydraulic excavator body is shown as viewed in the direction of arrow VI.

[0019] Figure 7 This is a rear view of the support structure of the exhaust treatment device.

[0020] Figure 8 This is a right side view of the support structure of the exhaust treatment device.

[0021] Figure 9 This is a perspective view showing the exhaust gas treatment device mounted on the support frame.

[0022] Figure 10 It is a three-dimensional diagram of the support frame.

[0023] Figure 11 It is a functional diagram schematically showing the path of the reducing agent and the path of the exhaust gas of the engine. DETAILED DESCRIPTION

[0024] Hereinafter, the embodiment will be described based on the accompanying drawings. In the following description, the same reference numerals are used for the same components. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[0025] In the embodiments, a rear-extra-small-swing hydraulic excavator is described as an example of a work machine. A rear-extra-small-swing hydraulic excavator is a hydraulic excavator whose rear-end swing radius allows full swing within 120% of the full width of the vehicle body, but whose front minimum swing radius exceeds 120% of the full width of the vehicle body, ensuring safety behind the vehicle body during swinging (based on the definition in Japanese Industrial Standards (JIS A 8340-4)). The concepts of the embodiments can also be applied to other types of work machines.

[0026] Figure 1 1 is a left side view schematically showing the structure of the hydraulic excavator 1 according to the embodiment. Figure 1 As shown, the hydraulic excavator 1 of this embodiment mainly includes a traveling structure 2, a revolving structure 3, and a working device 4. The traveling structure 2 and the revolving structure 3 constitute a vehicle body of the hydraulic excavator 1.

[0027] The traveling body 2 has a pair of left and right crawler tracks. The hydraulic excavator 1 is configured to be self-propelled by driving the pair of left and right crawler tracks to rotate. The revolving body 3 is mounted on the traveling body 2. The revolving body 3 is provided so as to be freely rotatable relative to the traveling body 2 via a revolving plate.

[0028] The revolving structure 3 includes a cab 10. The cab 10 is located on the left front portion of the revolving structure 3 (the front portion of the vehicle). The cab 10 is mounted on the body of the hydraulic excavator 1. An operating room is formed within the cab 10. The operating room is a space for an operator to operate the hydraulic excavator 1. A driver's seat is located within the operating room.

[0029] The working device 4 is a device for performing operations such as excavating sand and soil. The working device 4 includes a boom 4A, an arm 4B, a bucket 4C, a hydraulic cylinder 4D, and the like. The base end of the boom 4A is mounted on the revolving body 3 so as to be rotatable in both directions relative to the revolving body 3 about the boom pin. The base end of the arm 4B is mounted on the front end of the boom 4A so as to be rotatable in both directions relative to the boom 4A about the arm pin. The bucket 4C is mounted on the front end of the arm 4B so as to be rotatable in both directions relative to the arm 4B about the bucket pin. The boom 4A, the arm 4B, and the bucket 4C are driven by the hydraulic cylinder 4D, respectively, so as to drive the working device 4.

[0030] In this embodiment, the positional relationship between the various parts of the hydraulic excavator 1 will be described with reference to the work implement 4 .

[0031] The boom 4A of the working device 4 rotates and moves relative to the revolving body 3 with the boom pin as the center. The trajectory of movement of a specific part of the boom 4A that rotates relative to the revolving body 3, such as the front end of the boom 4A, is an arc, and a plane containing the arc is determined. When the hydraulic excavator 1 is viewed from above, the plane is represented as a straight line. The extension direction of the straight line is the front-to-back direction of the vehicle body, or the front-to-back direction of the revolving body 3, hereinafter referred to as the front-to-back direction. The left-right direction of the vehicle body (vehicle width direction), or the left-to-right direction of the revolving body 3 is a direction perpendicular to the front-to-back direction when viewed from above, hereinafter referred to as the left-to-right direction. The left-to-right direction refers to the extension direction of the boom pin. The up-down direction of the vehicle body, or the up-down direction of the revolving body 3 is a direction perpendicular to the plane determined by the front-to-back direction and the left-to-right direction, hereinafter referred to as the up-down direction.

[0032] In the front-to-back direction, the side where the work implement 4 protrudes from the vehicle body is the front direction, and the direction opposite the front direction is the rear direction. The right and left sides of the left-right direction, when viewed from the front, are the right and left directions, respectively. In the up-down direction, the side with the ground is the downside, and the side with the sky is the upside.

[0033] The front-to-back direction refers to the front-to-back direction of the operator seated in the driver's seat within cab 10. The left-to-right direction refers to the left-to-right direction of the operator seated in the driver's seat. The up-to-down direction refers to the up-to-down direction of the operator seated in the driver's seat. The direction facing the operator seated in the driver's seat is the front direction, and the direction behind the operator seated in the driver's seat is the rear direction. The right side and left side of the operator seated in the driver's seat when facing the front are the right and left directions, respectively. The lower side is the side below the operator seated in the driver's seat's feet, and the upper side is the side above the operator seated in the driver's seat.

[0034] exist Figure 1 In the following figures, the front-back direction X, the left-right direction Y, and the up-down direction Z are indicated by double arrows, respectively.

[0035] The work implement 4 is mounted on the front portion of the revolving structure 3. The work implement 4 is positioned to the right of the cab 10. The arrangement of the cab 10 and the work implement 4 is not limited to this example; the work implement 4 may be positioned to the left of the cab 10 positioned to the front right of the revolving structure 3.

[0036] Figure 2 It is enlarged to show Figure 1 The hydraulic excavator 1 is shown in a top view of the right rear portion of its vehicle body. Figure 3 It is from Figure 2 The figure is a rear view of the right rear portion of the vehicle body of the hydraulic excavator 1 as viewed in the direction of arrow III. Figure 4 It is from Figure 2 It is a right side view of the right rear portion of the vehicle body of the hydraulic excavator 1 as viewed in the direction of arrow IV shown.

[0037] like Figure 1 as well as Figures 2-4 As shown, the revolving body 3 has a body cover 8. The body cover 8 includes a top plate 8A that forms the upper surface of the revolving body 3. The engine, which is the driving source of the hydraulic excavator 1, is mounted on the revolving body 3. An engine compartment that houses the engine is provided on the revolving body 3. The body cover 8 includes an engine hood 8B that covers at least the upper portion of the engine compartment. The body cover 8 also includes a standing portion 8C for an operator to stand on during maintenance work.

[0038] like Figure 1 as well as Figures 2-4 As shown, a right camera 91, a rear camera 92, and a left camera 93 are mounted on the vehicle body cover 8. The right camera 91 faces rightward and captures images of terrain and obstacles to the right of the hydraulic excavator 1. The rear camera 92 faces rearward and captures images of terrain and obstacles to the rear of the hydraulic excavator 1. The left camera 93 faces leftward and captures images of terrain and obstacles to the left of the hydraulic excavator 1.

[0039] An exhaust gas treatment cover 70 is mounted on the top panel 8A of the vehicle body cover 8. Exhaust gas treatment cover 70 is positioned above the top panel 8A of the vehicle body cover 8. Exhaust gas treatment cover 70 protrudes upward from the top panel 8A of the vehicle body cover 8. To comply with exhaust gas regulations, exhaust gas treatment cover 70 covers at least the upper portion of the exhaust gas treatment device that processes engine exhaust.

[0040] An exhaust opening 75 is formed in the exhaust treatment cover 70. The exhaust pipe 15 through which the exhaust gas of the engine that has passed through the exhaust treatment device flows has an exhaust port 16 for discharging the exhaust gas into the atmosphere. The exhaust port 16 is exposed from the exhaust treatment cover 70 via the exhaust opening 75. The exhaust opening 75 is a circular opening, and an eaves portion 76 is provided at the upper edge of the exhaust opening 75. The eaves portion 76 protects the exhaust pipe 15 and suppresses the infiltration of moisture into the exhaust pipe 15 through the exhaust port 16. The exhaust opening 75 is formed on the rear surface of the exhaust treatment cover 70. The exhaust opening 75 is configured to be lower in height than the upper surface of the exhaust treatment cover 70. The exhaust port 16 is configured to be lower in height than the upper surface of the exhaust treatment cover 70.

[0041] Exhaust treatment cover 70 is formed with a plurality of ventilation holes 71-73, which are openings separate from exhaust opening 75. Ventilation hole 71 opens toward the right rear. Ventilation hole 72 opens toward the rear. Ventilation hole 73 opens toward the left rear. Ventilation holes 71-73 open toward the edge of revolving structure 3. Ventilation holes 71-73 do not open toward cab 10. Ventilation holes 71-73 do not open toward standing portion 8C.

[0042] Figure 5 It is a plan view of the right rear portion of the vehicle body of the hydraulic excavator 1 with the engine hood 8B and the exhaust treatment cover 70 removed. Figure 6 It is from Figure 5 The figure is a rear view of the right rear portion of the vehicle body of the hydraulic excavator 1 as viewed in the direction of arrow VI.

[0043] The engine 7 is a power source for driving the traveling structure 2 and the working device 4. The engine 7 is housed in an engine compartment below the engine hood 8B. The engine 7 is relatively heavy and is therefore positioned at the rear of the revolving structure 3 to balance its weight with the working device 4.

[0044] Exhaust gas from engine 7 is treated by first exhaust treatment device 12 and second exhaust treatment device 14. First exhaust treatment device 12 treats exhaust gas from engine 7. Second exhaust treatment device 14 treats exhaust gas that has passed through first exhaust treatment device 12.

[0045] First exhaust treatment device 12 is, for example, a diesel particulate filter device. The diesel particulate filter device primarily comprises a filter. The diesel particulate filter device captures particulate matter contained in the exhaust gas from engine 7 through the filter. The filter is made, for example, of ceramic. This diesel particulate filter device can reduce the concentration of particulate matter in the exhaust gas.

[0046] The second exhaust treatment device 14 is, for example, a selective catalyst reduction device. The selective catalyst reduction device reduces nitrogen oxides contained in the exhaust gas, for example, by reacting with a reducing agent, chemically converting the nitrogen oxides into harmless nitrogen gas, thereby reducing the concentration of nitrogen oxides in the exhaust gas. The selective catalyst reduction device is a device that treats the exhaust gas from the engine 7 and is used to hydrolyze urea water as a reducing agent to reduce nitrogen oxides NO. X The selective catalytic reduction device uses ammonia (NH3) to react with nitrogen oxides (NO X ) undergoes a chemical reaction and is reduced to nitrogen (N2) and water (H2O).

[0047] However, instead of loading ammonia on the hydraulic excavator 1, a reducing agent tank filled with urea water is mounted on the hydraulic excavator 1 as a reducing agent tank. As the reducing agent, urea water is preferably used, but is not limited to this, as long as it can reduce nitrogen oxides NO X of reducing agent.

[0048] It should be noted that, in this specification, the reducing agent and its precursor are collectively referred to as the "reducing agent." Furthermore, the first exhaust treatment device 12 may be a diesel oxidation catalyst device. Furthermore, the first exhaust treatment device 12 and the second exhaust treatment device 14 may be any combination of a diesel particulate filter device, a diesel oxidation catalyst device, and a selective catalyst reduction device.

[0049] First exhaust treatment device 12 and second exhaust treatment device 14 are arranged to the side of engine 7, for example, to the right of engine 7. First exhaust treatment device 12 is connected to second exhaust treatment device 14 via relay pipe 13. Relay pipe 13 is configured to guide exhaust gas that has passed through first exhaust treatment device 12 to second exhaust treatment device 14.

[0050] An exhaust pipe 15 is connected to the second exhaust treatment device 14. Exhaust pipe 15 is connected to the upper surface of the second exhaust treatment device 14 and extends upward from the second exhaust treatment device 14. Exhaust pipe 15 extends in the vertical direction Z. Exhaust gas after passing through the second exhaust treatment device 14 flows from bottom to top within exhaust pipe 15. Exhaust pipe 15 has an exhaust port 16 for discharging the exhaust gas into the atmosphere. Exhaust port 16 opens toward the rear of the hydraulic excavator 1. Therefore, exhaust gas is discharged toward the rear of the hydraulic excavator 1 from exhaust port 16.

[0051] Exhaust port 16 is formed at the upper end of exhaust pipe 15. Exhaust port 16 opens to the side of first exhaust treatment device 12. Exhaust port 16 is positioned so as to overlap first exhaust treatment device 12 in the vertical direction Z. Exhaust port 16 is located at a position lower than the top surface of first exhaust treatment device 12. Exhaust port 16 is located at a position higher than the top surface of second exhaust treatment device 14. Exhaust port 16 is located at a position higher than the top panel 8A of vehicle body cover 8.

[0052] The first exhaust treatment device 12 is arranged above the second exhaust treatment device 14. The first exhaust treatment device 12 is arranged above the top plate 8A of the vehicle body cover 8. Figures 2-4 First exhaust treatment device 12 is covered from above and to the sides by exhaust treatment cover 70. Second exhaust treatment device 14 is disposed below top panel 8A of vehicle body cover 8.

[0053] exist Figure 5 The axis L1 indicated by the dashed line in FIG. 1 represents the longitudinal direction of the first exhaust treatment device 12. The first exhaust treatment device 12 has a substantially cylindrical outer shape, and the axis L1 corresponds to the center line of the cylinder.

[0054] The longitudinal direction of the first exhaust treatment device 12, indicated by the axis L1, is inclined relative to the longitudinal direction X and the lateral direction Y of the hydraulic excavator 1. The exhaust gas within the first exhaust treatment device 12 flows from the front to the rear. The first exhaust treatment device 12 is arranged at an angle such that the upstream end of the exhaust gas flow is located forward of the downstream end and the upstream end of the exhaust gas flow is located to the right of the downstream end.

[0055] exist Figure 5 The axis L2 indicated by the dashed line in FIG. 1 represents the longitudinal direction of the second exhaust treatment device 14. The second exhaust treatment device 14 has a substantially cylindrical outer shape, and the axis L2 corresponds to the center line of the cylinder.

[0056] The longitudinal direction of second exhaust treatment device 14, indicated by axis L2, is inclined relative to the longitudinal direction X and the lateral direction Y of hydraulic excavator 1. Exhaust gas within second exhaust treatment device 14 flows from the front to the rear. Second exhaust treatment device 14 is arranged at an inclination such that the upstream end of the exhaust gas flow is located forward of the downstream end and the upstream end of the exhaust gas flow is located to the left of the downstream end.

[0057] The length direction of the first exhaust treatment device 12 is inclined relative to the length direction of the second exhaust treatment device 14. The length direction of the first exhaust treatment device 12 is not parallel to the length direction of the second exhaust treatment device 14. Figure 5 In the top view shown, the first exhaust treatment device 12 intersects the second exhaust treatment device 14. Figure 5 As shown, the first exhaust treatment device 12 and the second exhaust treatment device 14 are overlapped with each other as viewed from above along the vertical direction Z.

[0058] Standing portion 8C is configured to cover a portion of engine 7 from above. An operator can stand on standing portion 8C to operate engine 7, thereby performing maintenance work on engine 7. Standing portion 8C is located to the side of first exhaust treatment device 12, specifically to the left of first exhaust treatment device 12. An operator can stand on standing portion 8C to operate first exhaust treatment device 12, thereby performing maintenance work on first exhaust treatment device 12, such as cleaning or replacing the filter.

[0059] Figure 7 This is a rear view of the support structure of the exhaust treatment device. Figure 8 This is a right side view of the exhaust treatment device support structure. Figure 7 The middle figure shows the exhaust treatment device and its supporting structure viewed from the rear. Figure 8 The middle figure shows the exhaust treatment device and its supporting structure as viewed from the right.

[0060] The hydraulic excavator 1 includes a revolving frame 31. The engine 7 and the exhaust treatment device are arranged above and supported by the revolving frame 31. The rear edge of the revolving frame 31, when viewed from above, is formed into an arc shape centered on the rotation center of the revolving structure 3. The various devices mounted on the revolving frame 31, such as the engine 7 and the exhaust treatment device, are arranged so as to be housed within the arc-shaped revolving frame 31. This results in a rear-type, ultra-small revolving hydraulic excavator 1 with a reduced rearward revolving radius.

[0061] Refer to Figure 2 The rear edge of the vehicle body cover 8 covering the engine 7 is also formed in an arc shape. Figure 5The first exhaust treatment device 12 is arranged such that its longitudinal direction follows the arc shape of the rear edge of the revolving frame 31 (the rear edge of the vehicle body cover 8 ).

[0062] The revolving frame 31 has a pair of longitudinal plates 34L and 34R. The longitudinal plates 34L and 34R are located in the center of the revolving frame 31 in the left-right direction Y. The longitudinal plates 34L and 34R are formed by plates extending in the front-back direction X and the up-down direction Z and standing upward. The pair of longitudinal plates 34L and 34R are arranged at intervals from each other in the left-right direction Y. The longitudinal plate 34L is arranged to the left of the longitudinal plate 34R separately from the longitudinal plate 34R. The longitudinal plate 34R is arranged to the right of the longitudinal plate 34L separately from the longitudinal plate 34L. Working device 4 ( Figure 1 ) is supported at the front end portions of a pair of vertical plates 34L, 34R in a manner that allows relative rotation relative to the vertical plates 34L, 34R.

[0063] The revolving frame 31 includes a center frame 31C positioned between a pair of vertical plates 34L and 34R in the left-right direction Y, a left side frame 31L positioned to the left of the vertical plate 34L in the left-right direction Y, and a right side frame 31R positioned to the right of the vertical plate 34R in the left-right direction Y. The left side frame 31L is positioned to the left of the center frame 31C. The right side frame 31R is positioned to the right of the center frame 31C. The center frame 31C, the left side frame 31L, and the right side frame 31R are integrally formed.

[0064] A plurality of engine mount support portions 36 are integrally attached to the vertical plates 34L and 34R, for example, by welding. The engine 7 is mounted on the engine mount support portions 36 via the engine mounts 35, thereby being supported relative to the revolving frame 31. Providing the engine mount support portions 36 on the strong vertical plates 34L and 34R allows the heavy engine 7 to be supported on the revolving frame 31. The engine 7 is generally positioned between the vertical plates 34L and 34R.

[0065] A hydraulic pump 9 is positioned to the right of the engine 7. The hydraulic pump 9 is positioned to the right of the vertical plate 34R. The hydraulic pump 9 is connected to the output shaft of the engine 7 and operates by receiving power from the engine 7. The hydraulic pump 9 supplies hydraulic oil to various brakes, including the hydraulic cylinder 4D that drives the work implement 4, the travel motor that drives the traveling structure 2, and the swing motor that swings the swing structure 3 relative to the traveling structure 2. The first exhaust treatment device 12 and the second exhaust treatment device 14 are positioned above the hydraulic pump 9.

[0066] The support structure that supports the first exhaust treatment device 12 and the second exhaust treatment device 14 on the revolving frame 31 includes three column members 61, 62, and 63, and the support frame 40 (described later). The column members 61, 62, and 63 extend in the vertical direction, functioning as columns that bear compressive loads in the direction of their extension. The column members 61, 62, and 63 support the first exhaust treatment device 12 and the second exhaust treatment device 14 at three locations relative to the revolving frame 31. This ensures that the heavy first and second exhaust treatment devices 12 and 14 are stably supported on the revolving frame 31.

[0067] The column member 61 is supported by the vertical plate 34R via the engine mount support portion 36. The engine mount support portion 36, which protrudes leftward from the vertical plate 34R, is integrally formed with the vertical plate 34R, and the lower end of the column member 61 is attached to the engine mount support portion 36. The lower end of the column member 62 is attached to the right side frame 31R. The column member 62 is positioned at a position separated to the right from the vertical plate 34R. The lower end of the column member 63 is attached to the center frame 31C directly to the left of the vertical plate 34R. The column member 63 is positioned between the pair of vertical plates 34L and 34R, and is located near the rear edge of the revolving frame 31.

[0068] The pillar members 61, 62, and 63 are arranged in this order from the front to the rear in the front-rear direction X. The pillar members 62, 61, and 63 are arranged in this order from the right to the left in the left-right direction Y. The pillar members 61, 62, and 63 are fixed to the revolving frame 31 using fastening members such as bolts.

[0069] Figure 9 It is a perspective view showing first exhaust treatment device 12 and second exhaust treatment device 14 mounted on support frame 40 . Figure 10 It is a perspective view of the support frame 40. Figure 10 In the figure, it is shown that Figure 9 Omitted Figure 9 The first exhaust treatment device 12, the second exhaust treatment device 14, the introduction pipe 11, the relay pipe 13, and the exhaust pipe 15 are shown in the illustrated state.

[0070] Reference Figure 7 、 8 as well as Figure 8 、 9The first exhaust treatment device 12 is connected to the engine 7 via an inlet pipe 11. The inlet pipe 11 is configured to guide the exhaust gas discharged from the engine 7 to the first exhaust treatment device 12. The inlet pipe 11 passes through the side of the second exhaust treatment device 14 and extends in the up-down direction, and is connected to the lower surface of the first exhaust treatment device 12. The exhaust gas from the engine 7 flows from bottom to top in the inlet pipe 11 and flows into the first exhaust treatment device 12 from below. Figure 8 As shown, the introduction pipe 11 is arranged closer to the right side edge of the revolving frame 31 than the second exhaust treatment device 14 .

[0071] Inlet pipe 11 is connected to one end in the longitudinal direction of first exhaust treatment device 12. Inlet pipe 11 is connected to the upstream end of first exhaust treatment device 12 in the direction of exhaust gas flow. Because the longitudinal direction of first exhaust treatment device 12 is inclined with respect to the front-to-back direction X and the left-to-right direction Y, inlet pipe 11 is connected to the front end of first exhaust treatment device 12 in the front-to-back direction X and to the right end of first exhaust treatment device 12 in the left-to-right direction Y.

[0072] A relay pipe 13 that guides the exhaust gas after passing through the first exhaust treatment device 12 to the second exhaust treatment device 14 is connected to the bottom surface of the first exhaust treatment device 12 and to the side surface of the second exhaust treatment device 14 .

[0073] Relay pipe 13 is connected to the other longitudinal end of first exhaust treatment device 12. Relay pipe 13 is connected to the downstream end of first exhaust treatment device 12 in the exhaust flow direction. Because the longitudinal direction of first exhaust treatment device 12 is inclined relative to the front-to-back direction X and the left-to-right direction Y, relay pipe 13 is connected to the rear end of first exhaust treatment device 12 in the front-to-back direction X and to the left end of first exhaust treatment device 12 in the left-to-right direction Y.

[0074] The relay pipe 13 includes a vertical pipe portion extending downward from the first exhaust treatment device 12, and a horizontal pipe portion bent from the lower end of the vertical pipe portion and extending along the second exhaust treatment device 14. The longitudinal direction of the horizontal pipe portion is substantially the same as the longitudinal direction of the second exhaust treatment device 14. Figure 5 Junction pipe 13 is disposed to the left of second exhaust treatment device 14. Junction pipe 13 is disposed closer to engine 7 than second exhaust treatment device 14. Junction pipe 13 is located farther from the right side edge of revolving frame 31 than second exhaust treatment device 14.

[0075] The cross pipe section includes a large-diameter portion 13A, where the diameter of the relay pipe 13 is enlarged, near the upstream end of the exhaust gas flow. An injector 27 is mounted in the large-diameter portion 13A. The injector 27 injects the reducing agent into the relay pipe 13. The relay pipe 13 functions as a mixing pipe, injecting the reducing agent into the exhaust gas and mixing the two. Because the injector 27 is connected to the upstream side of the relay pipe 13, the reducing agent supplied to the relay pipe 13 mixes with the exhaust gas before reaching the second exhaust treatment device 14.

[0076] Relay pipe 13 is connected to one end of the second exhaust treatment device 14 in the longitudinal direction. Relay pipe 13 is connected to the upstream end of second exhaust treatment device 14 in the direction of exhaust gas flow. Because the longitudinal direction of second exhaust treatment device 14 is inclined relative to the front-to-back direction X and the left-to-right direction Y, relay pipe 13 is connected to the front end of second exhaust treatment device 14 in the front-to-back direction X and to the left end of second exhaust treatment device 14 in the left-to-right direction Y. Relay pipe 13 is connected to the left surface of second exhaust treatment device 14.

[0077] An exhaust pipe 15 is connected to the other end of the second exhaust treatment device 14 in the longitudinal direction. The exhaust pipe 15 is connected to the downstream end of the second exhaust treatment device 14 in the exhaust flow direction. Since the longitudinal direction of the second exhaust treatment device 14 is inclined with respect to the front-rear direction X and the left-right direction Y, the exhaust pipe 15 is connected to the rear end of the second exhaust treatment device 14 in the front-rear direction X and to the right end of the second exhaust treatment device 14 in the left-right direction Y. Figure 5 、 6 Exhaust pipe 15 is arranged to the right of first exhaust treatment device 12 and to the rear of first exhaust treatment device 12. Exhaust pipe 15 is arranged closer to the edge of revolving frame 31 than first exhaust treatment device 12.

[0078] Figure 10 The support frame 40 shown is mounted on the reference Figure 7 、 8 The first exhaust treatment device 12 and the second exhaust treatment device 14 are supported by the support frame 40. The first exhaust treatment device 12 and the second exhaust treatment device 14 are supported by the support frame 40. The first exhaust treatment device 12 and the second exhaust treatment device 14 are supported by the support frame 40 on the column members 61, 62, and 63 via the support frame 40. The support frame 40 is supported by the revolving frame 31 via the column members 61, 62, and 63. The first exhaust treatment device 12 and the second exhaust treatment device 14 are supported by the support structure including the support frame 40 and the column members 61, 62, and 63.

[0079] The support frame 40 mainly includes a first bottom plate portion 41 , beam portions 46 and 47 , a second bottom plate portion 51 , wall members 57 and 58 , and a junction pipe support portion 66 .

[0080] The first bottom plate portion 41 constitutes a layer portion of the support frame 40. The first bottom plate portion 41 is arranged above the hydraulic pump 9. Of the first exhaust treatment device 12 and the second exhaust treatment device 14, the second exhaust treatment device 14 arranged below is mounted on the first bottom plate portion 41. The first bottom plate portion 41 has a generally flat plate shape and extends generally horizontally. Figure 6 The first bottom plate portion 41 is arranged at a position lower than the top plate 8A of the vehicle body cover 8 .

[0081] A pair of support brackets 42 and 43 are mounted on the upper surface of first bottom plate 41. Support brackets 42 and 43 are arranged side by side and spaced apart in the longitudinal direction of second exhaust treatment device 14. Mounting tools 44 are mounted on support bracket 42, and mounting tools 45 are mounted on support bracket 43. Mounting tools 44 and 45 are, for example, U-bolts.

[0082] like Figure 9 As shown, second exhaust treatment device 14 is mounted on a pair of support brackets 42 and 43. In this state, a generally U-shaped mounting tool 44 surrounds the upper surface and side surfaces of the cylindrical second exhaust treatment device 14, with both ends of mounting tool 44 secured to support bracket 42. A generally U-shaped mounting tool 45 surrounds the upper surface and side surfaces of the second exhaust treatment device 14, with both ends of mounting tool 45 secured to support bracket 43. In this manner, second exhaust treatment device 14 is mounted on first bottom plate 41 and supported from below by first bottom plate 41.

[0083] The second bottom plate portion 51 constitutes the second layer of the support frame 40. The second bottom plate portion 51 is arranged above the first bottom plate portion 41. The second bottom plate portion 51 is arranged above the second exhaust treatment device 14 mounted on the first bottom plate portion 41. Of the first exhaust treatment device 12 and the second exhaust treatment device 14, the first exhaust treatment device 12 arranged above is mounted on the second bottom plate portion 51. The second bottom plate portion 51 has a generally flat plate shape and extends generally horizontally. The first bottom plate portion 41 and the second bottom plate portion 51 extend generally parallel to each other. Refer to Figure 6 The second bottom plate portion 51 is arranged at a position higher than the top plate 8A of the vehicle body cover 8 .

[0084] A pair of support brackets 52 and 53 are mounted on the upper surface of the second bottom plate 51. Support brackets 52 and 53 are arranged side by side and spaced apart in the longitudinal direction of the first exhaust treatment device 12. An attachment tool 54 is attached to support bracket 52, and an attachment tool 55 is attached to support bracket 53. Attachment tools 54 and 55 are, for example, U-bolts.

[0085] like Figure 9 As shown, first exhaust treatment device 12 is mounted on a pair of support brackets 52 and 53. In this state, a generally U-shaped mounting tool 54 surrounds the upper surface and side surfaces of the cylindrical first exhaust treatment device 12, with both ends of mounting tool 54 secured to support bracket 52. A generally U-shaped mounting tool 55 surrounds the upper surface and side surfaces of the first exhaust treatment device 12, with both ends of mounting tool 55 secured to support bracket 53. In this manner, first exhaust treatment device 12 is mounted on second bottom plate 51 and supported from below by second bottom plate 51.

[0086] Wall members 57 and 58 extend generally in the vertical direction, connecting first floor portion 41 and second floor portion 51, and supporting second floor portion 51 above first floor portion 41. When second exhaust treatment device 14 is mounted on first floor portion 41, second exhaust treatment device 14 is positioned between wall members 57 and 58, with wall members 57 and 58 positioned on either side of second exhaust treatment device 14. In the left-right direction Y, wall member 57 is positioned to the right of second exhaust treatment device 14, while wall member 58 is positioned to the left of second exhaust treatment device 14. The support structure for first exhaust treatment device 12, including second floor portion 51 and wall members 57 and 58, is positioned so as to straddle second exhaust treatment device 14.

[0087] Wall member 58 has an opposing surface facing wall member 57 and an opposite surface opposite to the opposing surface. A junction pipe support 66 is attached to the opposite surface of wall member 58. An attachment tool 67 is attached to junction pipe support 66. Attachment tool 67 is, for example, a U-bolt.

[0088] like Figure 9 As shown, a substantially U-shaped mounting tool 67 surrounds the upper surface, lower surface, and one side surface of the relay pipe, and both ends of the mounting tool 67 are fixed to the relay pipe support portion 66 , whereby the relay pipe 13 is supported by the relay pipe support portion 66 .

[0089] Beam 46 is fixed to the upper surface of first bottom plate 41. Beam 47 is fixed to the lower surface of first bottom plate 41. Beam 46 extends along the front-rear direction X. The front end of beam 46 is fixed to the upper portion of pillar member 61. The rear end of beam 46 is fixed to the upper end of pillar member 63. Beam 47 extends along the left-right direction Y. Beam 47 is arranged to extend rightward from beam 46, with the left end of beam 47 located below beam 46. The right end of beam 47 is supported by pillar member 62.

[0090] The support frame 40 having such a structure, and the first exhaust treatment device 12 and the second exhaust treatment device 14 mounted on the support frame 40 are composed of Figure 7、 8 The three column members 61 , 62 , and 63 shown are supported from below and supported on the revolving frame 31 via the column members 61 , 62 , and 63 .

[0091] Figure 11 Schematically shows the path of the reducing agent 90 and the path of the exhaust gas of the engine 7. Figure 11 As shown, exhaust gas from engine 7 passes through inlet pipe 11, first exhaust treatment device 12, relay pipe 13, second exhaust treatment device 14, and exhaust pipe 15 in this order before being discharged into the atmosphere. An ejector 27 is provided in relay pipe 13 upstream of second exhaust treatment device 14 in the flow of the exhaust gas. Ejector 27 includes an injection nozzle 28.

[0092] Reducing agent 90 is stored within the reducing agent tank 20. A suction pipe 24 is disposed within the reducing agent tank 20, allowing the reducing agent 90 to flow out of the reducing agent tank 20. A coarse filter 26 is connected to the distal end of the suction pipe 24. The suction pipe 24 is connected to the delivery pipe 21. The reducing agent 90 drawn from the reducing agent tank 20 is transferred by the reducing agent pump 22, sequentially passing through the delivery pipe 21 and the pressure delivery pipe 25, and finally reaching the injector 27. The reducing agent 90 not used in exhaust gas treatment is returned from the reducing agent pump 22 to the reducing agent tank 20 via the return pipe 23.

[0093] Injector 27 supplies reducing agent 90 drawn from reducing agent tank 20 to relay pipe 13, located upstream of the exhaust gas flow from second exhaust treatment device 14. Reducing agent 90 is injected into exhaust gas flowing through relay pipe 13 via injection nozzle 28. In second exhaust treatment device 14, nitrogen oxides contained in the exhaust gas react with reducing agent 90, reducing the concentration of nitrogen oxides in the exhaust gas. If reducing agent 90 is urea water, the urea water decomposes into ammonia within relay pipe 13. The reaction between nitrogen oxides and ammonia decomposes the nitrogen oxides into harmless nitrogen and oxygen. Exhaust gas with the nitrogen oxide content reduced to an appropriate level is discharged from exhaust port 16.

[0094] Although some of the descriptions are repeated above, the characteristic configuration and effects of this embodiment are summarized as follows.

[0095] like Figure 5 As shown, the longitudinal direction of first exhaust treatment device 12, indicated by axis L1, is inclined relative to the longitudinal direction X and the lateral direction Y of hydraulic excavator 1. Furthermore, the longitudinal direction of first exhaust treatment device 12 is inclined relative to the longitudinal direction of second exhaust treatment device 14, indicated by axis L2.

[0096] By arranging first exhaust treatment device 12 and second exhaust treatment device 14 in this manner, multiple exhaust treatment devices can be appropriately arranged within the limited area of ​​revolving frame 31. Furthermore, the paths of the piping connected to first exhaust treatment device 12 and second exhaust treatment device 14 can be appropriately set. By appropriately arranging the exhaust treatment devices and piping, the required area of ​​standing section 8C, which serves as a space for maintenance work on engine 7 and first exhaust treatment device 12, can be ensured, thus preventing a reduction in the workability of maintenance work.

[0097] like Figure 5 As shown, first exhaust treatment device 12 is arranged above second exhaust treatment device 14, and in a plan view, first exhaust treatment device 12 intersects second exhaust treatment device 14. By stacking first exhaust treatment device 12 and second exhaust treatment device 14 in the vertical direction Z, the area occupied by first exhaust treatment device 12 and second exhaust treatment device 14 is reduced, allowing multiple exhaust treatment devices to be appropriately arranged on the limited area of ​​revolving frame 31.

[0098] like Figure 8 As shown, inlet pipe 11, which guides exhaust gas from engine 7 to first exhaust treatment device 12, passes beside second exhaust treatment device 14 and extends in the vertical direction, connecting to the bottom surface of first exhaust treatment device 12. First exhaust treatment device 12, located above second exhaust treatment device 14, is arranged at an angle relative to second exhaust treatment device 14, with their longitudinal directions intersecting. This allows the upper end of inlet pipe 11, which extends in the vertical direction, to connect to the bottom surface of first exhaust treatment device 12. The appropriately designed path of inlet pipe 11 shortens its length and reduces pressure loss in the exhaust gas flowing through it.

[0099] like Figure 9 As shown, relay pipe 13, which guides exhaust gas after passing through first exhaust treatment device 12 to second exhaust treatment device 14, is connected to the bottom surface of first exhaust treatment device 12 and to the side surface of second exhaust treatment device 14. First exhaust treatment device 12, located above second exhaust treatment device 14, is arranged at an angle relative to second exhaust treatment device 14, with their lengths intersecting. This allows the upstream end of relay pipe 13 to be connected to the bottom surface of first exhaust treatment device 12. Relay pipe 13 can be arranged from below the location where it is connected to first exhaust treatment device 12, along second exhaust treatment device 14. This allows the route of relay pipe 13 to be appropriately set, thereby shortening its length.

[0100] like Figure 6As shown, an exhaust pipe 15, through which exhaust gas flows after passing through the second exhaust treatment device 14, has an exhaust port 16 for discharging the exhaust gas into the atmosphere. Exhaust port 16 opens to the rear of the hydraulic excavator 1 on the side of the first exhaust treatment device 12. By positioning exhaust port 16 at the upper end of exhaust pipe 15 at a lower height than the upper surface of the first exhaust treatment device 12, exhaust pipe 15 can be prevented from obstructing the operator's field of vision in cab 10, thereby ensuring visibility to the right rear of the hydraulic excavator 1.

[0101] like Figures 2-4 As shown, the first exhaust treatment device 12 is covered by an exhaust treatment cover 70. By removing the exhaust treatment cover 70, the first exhaust treatment device 12 can be easily accessed, thereby facilitating regular maintenance work on the first exhaust treatment device 12. A plurality of ventilation holes 71 to 73 are formed in the exhaust treatment cover 70. In the case where the first exhaust treatment device 12 is a diesel particulate filter device, particulate matter captured by the filter is burned and regenerated, thereby generating heat. By forming a plurality of ventilation holes 71 to 73 in the exhaust treatment cover 70 covering the first exhaust treatment device 12, ventilation of the housing space of the first exhaust treatment device 12 can be easily performed, thereby suppressing a temperature increase in the housing space of the first exhaust treatment device 12.

[0102] like Figure 5 As shown, the rear edge of the revolving frame 31 supporting the engine 7 is formed into an arc shape in a plan view. The first exhaust treatment device 12 is arranged so that its longitudinal direction extends along the rear edge of the revolving frame 31. By appropriately arranging multiple exhaust treatment devices and piping, multiple exhaust treatment devices can be easily installed on a rear-type ultra-small revolving hydraulic excavator 1 with a small revolving frame 31 area.

[0103] It should be understood that the embodiments and examples disclosed herein are illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the technical claims rather than the above description, and is intended to include all changes within the meaning and scope of the technical claims.

[0104] Description of reference numerals:

[0105] 1...Hydraulic excavator; 2...Traveling body; 3...Swinging body; 4...Working device; 7...Engine; 8...Body cover; 8A...Roof panel; 8B...Hood; 8C...Standing section; 10...Operating cab; 11...Inlet pipe; 12...First exhaust treatment device; 13...Relay pipe; 13A...Large diameter section; 14...Second exhaust treatment device; 15...Exhaust pipe; 16...Exhaust port; 27...Injector; 31...Swinging frame; 31C...Center frame; 31L...Left frame; 31R. ..right side frame; 34L, 34R...longitudinal plate; 35...engine mounting member; 40...support frame; 41...first bottom plate portion; 42, 43, 52, 53...support bracket; 44, 45, 54, 55, 67...installation tool; 46, 47...beam portion; 51...second bottom plate portion; 57, 58...wall member; 61, 62, 63...column member; 66...relay pipe support portion; 70...exhaust treatment cover; 71-73...ventilation holes; 75...exhaust opening; 76...eaves; L1, L2...axis line.

Claims

1. A working machine, wherein: The operating machine comprises: engine; a first exhaust treatment device for treating exhaust gas discharged from the engine; as well as a second exhaust treatment device for treating the exhaust gas after passing through the first exhaust treatment device; The longitudinal direction of the first exhaust treatment device is inclined relative to the front-rear direction and the left-right direction, and is inclined relative to the longitudinal direction of the second exhaust treatment device. The first exhaust treatment device is arranged above the second exhaust treatment device. In a plan view, the first exhaust treatment device intersects the second exhaust treatment device.

2. The working machine according to claim 1, wherein: The working machine further includes an introduction pipe that guides exhaust gas discharged from the engine to the first exhaust treatment device. The introduction pipe passes through a side of the second exhaust treatment device, extends in the up-down direction, and is connected to a lower surface of the first exhaust treatment device.

3. The working machine according to claim 1 or 2, wherein: The working machine further includes a relay pipe that guides the exhaust gas that has passed through the first exhaust treatment device to the second exhaust treatment device. The relay pipe is connected to the bottom surface of the first exhaust treatment device and is connected to the side surface of the second exhaust treatment device.

4. The working machine according to claim 1 or 2, wherein: The working machine further includes an exhaust pipe through which the exhaust gas passing through the second exhaust treatment device flows. The exhaust pipe has an exhaust port for discharging exhaust gas into the atmosphere. The exhaust port opens toward the rear of the work machine on a side of the first exhaust treatment device.

5. The working machine according to claim 1 or 2, wherein: The working machine further comprises: an engine room housing the engine; and a body shell covering the engine compartment, The first exhaust treatment device is arranged above the top plate of the vehicle body cover. The working machine further includes an exhaust gas treatment cover, the exhaust gas treatment cover being mounted on the top plate and covering the first exhaust gas treatment device. A plurality of ventilation holes are formed on the exhaust treatment cover.

6. The working machine according to claim 1 or 2, wherein: The working machine further includes a revolving frame, the revolving frame supporting the engine. The rear edge of the revolving frame is formed into an arc shape in a plan view. The first exhaust treatment device is arranged such that its longitudinal direction is along the trailing edge.

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