Engine exhaust pipe system

Abstract

To prevent, while the moisture contained in engine exhaust is discharged to the outside of an exhaust pipe, dirt components contained in the moisture from polluting the surroundings.SOLUTION: An engine exhaust pipe device 50 includes: an inlet pipe 53 connected to an exhaust outlet of an engine; a swirl flow pipe 60 for converting engine exhaust, which is introduced to the inside from the inlet pipe 53, into a swirl flow; an outlet pipe 55 for discharging the engine exhaust exhausted from the swirl flow pipe 60 to the outside; and a pipe body 61 having a cylindrical space in the swirl flow pipe 60. An inlet-side exhaust passage of the inlet pipe 53 is connected in a direction along a plane intersecting a central axis of the cylindrical space and eccentrically to the central axis, so that the engine exhaust forms a swirl flow in the cylindrical space. A water drain hole is provided on the downstream side of the swirl flow, and in the inside of the pipe body 61, the moisture contained in the engine exhaust adheres to an inner peripheral surface by the centrifugal force generated by the swirl flow of the engine exhaust to form water droplets and is discharge to the outside through the water drain hole.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an engine exhaust pipe device that is provided at a location where exhaust gas from an engine is discharged. [Background technology]

[0002] Engines (internal combustion engines) are widely used in work equipment such as shovel loaders and power shovels (also called excavators or backhoes) used to excavate the ground and move excavated soil, etc. One such work vehicle has an operator's cabin on the vehicle base, where the operator sits, and an engine room that houses the engine is located behind the operator's cabin.

[0003] Among such work vehicles, there are work vehicles that house a silencer (hereinafter also referred to as a muffler) in the engine compartment to reduce exhaust noise from the engine, and are equipped with an air conditioning system to regulate the temperature inside the operator's cabin. In work vehicles equipped with an air conditioning system, an air conditioning unit (comprising an evaporator, heater core, blower fan, etc.) for blowing cool air and warm air into the operator's cabin is provided inside the operator's cabin, and a compressor for compressing the air conditioning refrigerant, a condenser for condensing the compressed refrigerant, etc. are located inside the engine compartment (see, for example, Patent Documents 1 and 2 listed below). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 3920679 [Patent Document 2] Patent No. 4388458 Summary of the Invention [Problem to be solved by the invention]

[0005] Exhaust from an engine contains moisture (steam), which liquefies inside the exhaust pipe and is discharged from the exhaust pipe to the outside. Moisture condenses easily, particularly immediately after a cold start of the engine, and this condensed water is discharged to the outside through the exhaust pipe along with the exhaust gas. Because exhaust from the exhaust pipe is discharged to the outside at a fairly high speed, the exhaust is dispersed widely around the exhaust pipe. The water and moisture that is dispersed and discharged in this manner contains contaminants, which can contaminate the vehicle body and engine cover around the exhaust pipe, as well as buildings and people (workers and passersby) around the work vehicle equipped with this engine.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide an engine exhaust pipe device that is configured to prevent the moisture contained in the exhaust from the engine and the liquid water that results from condensation of this moisture from being discharged outside the exhaust pipe, and to prevent the surrounding area from being polluted by the dirty components contained in the moisture. [Means for solving the problem]

[0007] In order to achieve the above object, the engine exhaust pipe device of the present invention is an engine exhaust pipe device that is connected to an exhaust outlet of an engine in a work vehicle equipped with an engine, and is configured to include an inlet exhaust pipe member (e.g., an inlet pipe in the embodiments) that is connected to the exhaust outlet of the engine and has an inlet-side exhaust passage therein, a swirl flow generating device (e.g., a swirl flow pipe in the embodiments) that is connected to the inlet-side exhaust passage and converts the engine exhaust introduced therein into a swirl flow, and an outlet exhaust pipe member (e.g., an outlet pipe in the embodiments) that has an outlet-side exhaust passage that discharges the engine exhaust discharged from the swirl flow generating device to the outside, and the swirl flow generating device flows the swirl flow generated by converting the engine exhaust Cylindrical A main body member (for example, a pipe main body in the embodiment) having an internal space, Cylindrical It has a drain hole that opens into the internal space. can.

[0008] The engine exhaust pipe device further comprises: an inlet exhaust pipe member connected to the main body member at one axial end side of the cylindrical internal space; and an inlet-side exhaust passage of the inlet exhaust pipe member connected to the main body member at one axial end side of the cylindrical internal space. internal The exhaust passage extends in a direction along a plane intersecting the central axis of the space and is connected eccentrically with respect to the central axis. internal The engine exhaust gas flowing into the space is internal the exhaust pipe member is configured to form a swirling flow within the cylindrical internal space, the outlet exhaust pipe member projects from one end side of the main body member into the cylindrical internal space and extends toward the other end of the cylindrical internal space, and the engine exhaust that has become a swirling flow at the one end side of the cylindrical internal space moves within the cylindrical internal space toward the other end side, the outlet exhaust pipe member The water contained in the engine exhaust is caused to adhere to the inner peripheral surface that forms the cylindrical internal space by centrifugal force generated by the swirling flow of the engine exhaust in the cylindrical internal space, turning into droplets, which are then discharged to the outside through the drain hole.

[0009] Furthermore, in the engine exhaust pipe device, it is preferable that the cylindrical internal One end of the space End is covered by a diagonally extending one end side lid, and the inlet exhaust pipe member is connected to the main body member at a position facing the one end side lid, and the cylindrical exhaust pipe passes through the inlet side exhaust passage. internal The engine exhaust gas flowing into the space is internal The flow becomes a swirling flow in the space, and when it hits the one end cover, it is pushed along the obliquely extending direction, forming the cylindrical shape. internal It is configured to flow to the other end of the space.

[0010] In the engine exhaust pipe device, preferably, the cylindrical body member internal The space is provided so as to be inclined obliquely downward from the one end side cover toward the other end side, and the cylindrical internal The drain hole is provided at the other end of the space.

[0011] Another engine exhaust pipe device according to the present invention is an engine exhaust pipe device that is connected to an exhaust outlet of an engine in a work vehicle equipped with an engine, and is configured to include: an inlet exhaust pipe member that is connected to the exhaust outlet of the engine and has an inlet-side exhaust passage therein; a swirl flow generating device that is connected to the inlet-side exhaust passage and converts the engine exhaust introduced therein into a swirl flow; and an outlet exhaust pipe member that has an outlet-side exhaust passage that discharges the engine exhaust discharged from the swirl flow generating device to the outside, wherein the swirl flow generating device is lower end The inlet side is connected to the exhaust passage on the inlet side, top end The outlet side of the exhaust passage is connected to the outlet side of the exhaust passage. Extends up and down a main body member having an internal space; Up and down The swirl flow converter is provided in the middle portion, and a drain hole is provided so as to open into the internal space, and the internal space is connected to the inlet-side exhaust passage by the swirl flow converter. Located below along with The inlet side space and the outlet side exhaust passage are connected to each other. Located on the upper side together with The exhaust gas flow passing through the inlet-side exhaust passage into the inlet-side space is converted into a swirl flow by the swirl flow converter and flows into the outlet-side space. do.

[0012] In the above engine exhaust pipe device, Furthermore, the internal space is formed as a cylindrical space extending upward from the inlet side space through the swirl flow conversion device toward the outlet side space, and a capture groove is formed on the inner surface of the internal space extending up and down from the outlet side space to the inlet side space, and the water drain hole is formed opening into the inlet side space, and the centrifugal force generated by the swirl flow of the engine exhaust in the outlet side space causes the moisture contained in the engine exhaust to adhere to the inner surface forming the outlet side space, turning into droplets, which then flow into the inlet side space via the capture groove and are discharged to the outside through the water drain hole.

[0013] Furthermore, in the engine exhaust pipe device, preferably, The drain hole is formed in the inlet space at the lower end of the capture groove. [Effects of the Invention]

[0015] According to the engine exhaust pipe device of the present invention, the swirl flow generating device includes a main body member having an internal space through which the swirl flow generated by converting engine exhaust gas flows, and a drain hole provided in the internal space. The centrifugal force generated by the swirl flow of the engine exhaust gas in the internal space causes moisture contained in the engine exhaust gas to adhere to the inner circumferential surface defining the internal space, forming droplets, which are then discharged to the outside through the drain hole. That is, the moisture contained in the engine exhaust gas is separated and discharged through the drain hole, and the dehydrated exhaust gas is discharged to the outside through the exhaust pipe. As a result, moisture is discharged together with the exhaust gas from the exhaust pipe, effectively preventing contamination of the surrounding area caused by contaminants contained in the moisture. In particular, immediately after a cold start of the engine, moisture is likely to condense, and the condensed water is discharged together with the exhaust gas from the exhaust pipe, potentially causing contamination of the surrounding area. However, the engine exhaust pipe device of the present invention effectively prevents this problem.

[0016] In the above engine exhaust pipe device, it is preferable that the internal space of the main body member has a cylindrical space that functions as a swirl flow generating device, and the inlet-side exhaust passage of the inlet exhaust pipe member extends in a direction along a plane that intersects with the central axis of the cylindrical space and is connected eccentrically with respect to the central axis. With this configuration, the engine exhaust that passes through the inlet-side exhaust passage and flows into the cylindrical space can be made to swirl within the cylindrical space, and moisture in the engine exhaust can be effectively removed by this swirl flow.

[0017] Furthermore, in this engine exhaust pipe device, it is preferable that one end of the cylindrical space is covered by an end cap that extends obliquely, and the inlet exhaust pipe member is connected to the main body member at a position opposite the end cap. With this configuration, engine exhaust passing through the inlet exhaust passage and flowing into the cylindrical space becomes a swirling flow within the cylindrical space and is pushed along the oblique direction by the end cap to flow to the other end of the cylindrical space, allowing the generated swirling flow to flow smoothly toward the outlet exhaust pipe member.

[0018] Furthermore, in this engine exhaust pipe device, it is preferable that the cylindrical space of the main body member be formed so as to slope obliquely downward from the one end cover toward the other end, and that the drain hole be formed at the other end of the cylindrical space. In this way, centrifugal force generated by the swirling flow of the engine exhaust causes moisture contained in the engine exhaust to adhere to the inner circumferential surface that forms the cylindrical space and turn into water droplets, and then the water droplets flow along the obliquely downward slope and can be efficiently discharged from the drain hole formed at the lower end (i.e., the other end).

[0019] According to another engine exhaust pipe device of the present invention, the swirl flow generating device includes a main body member having the internal space, a swirl flow converter disposed in the middle of the internal space, and a drain hole disposed in the internal space. The internal space is divided into an inlet space and an outlet space by the swirl flow converter, so that the engine exhaust flow passing through the inlet exhaust passage and flowing into the inlet space is converted into a swirl flow by the swirl flow converter and flows into the outlet space. Therefore, the centrifugal force generated by the swirl flow of the engine exhaust in the outlet space causes moisture contained in the engine exhaust to adhere to the inner circumferential surface forming the outlet space, forming droplets, which can then be efficiently discharged to the outside through the drain hole. As a result, moisture is discharged from the exhaust pipe together with the exhaust, effectively preventing contamination of the surrounding area by contaminants contained in the moisture. In particular, immediately after a cold start of the engine, moisture is likely to condense and the condensed water is discharged from the exhaust pipe together with the exhaust gas to the outside, polluting the surrounding area, but the engine exhaust pipe device according to the present invention can effectively prevent this problem.

[0020] Furthermore, in the engine exhaust pipe device, it is preferable that the inlet-side exhaust pipe member is connected to the lower end of the main body member and the outlet-side exhaust pipe member is connected to the upper end of the main body member, and the internal space is formed as a cylindrical space extending upward from the inlet-side space through the swirl flow converter toward the outlet-side space, thereby effectively generating a swirl flow in the outlet space.

[0021] Furthermore, in the engine exhaust pipe device, it is preferable that a trap groove is formed on the inner circumferential surface that defines the cylindrical space, extending vertically from the outlet space to the inlet space, and the drain hole is formed in the inlet space at a lower end of the trap groove, so that water droplets can be effectively trapped in the trap groove and can flow downward within the trap groove and be smoothly discharged from the drain hole that opens at the lower end.

[0022] Furthermore, in the engine exhaust pipe device, it is preferable that the internal space in the main body member is formed as a cylindrical space extending obliquely downward from the inlet space through the swirl flow converter toward the outlet space, and the drain hole is formed so as to open at a lower end of the outlet space. In this way, water that has been converted into droplets by the swirl flow in the outlet space can be made to flow obliquely downward and effectively discharged from the drain hole. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a perspective view of a power shovel on which an engine equipped with an engine exhaust pipe device according to the present invention is mounted. [Figure 2] FIG. 2 is a perspective view showing the power shovel with an engine cover open. [Figure 3] FIG. 2 is a perspective view of an engine mounted on the power shovel. [Figure 4] 5A to 5C are five views (plan view, front view, left and right side views, and bottom view) showing an engine exhaust pipe device provided in the engine. [Figure 5]5(a) and 5(b) are cross-sectional views of the engine exhaust pipe device taken along the line AA and BB, respectively, shown in FIG. 4(b). [Figure 6] FIG. 5 is a cross-sectional view of the engine exhaust pipe device taken along the line CC in FIG. 4(d). [Figure 7] FIG. 5 is a cross-sectional view of the engine exhaust pipe device taken along the line DD in FIG. 4(d). [Figure 8] FIG. 8 is a cross-sectional view corresponding to FIG. 7, showing a modified embodiment of the engine exhaust pipe device. [Figure 9] FIG. 10 is an external perspective view showing a different embodiment of an engine exhaust pipe device according to the present invention. [Figure 10] 1 is a perspective view showing the exterior of an engine exhaust pipe device according to this embodiment, with a partial cross section. [Figure 11] FIG. 4 is a cross-sectional view showing another embodiment of an engine exhaust pipe device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In this embodiment, an example in which the present invention is applied to a wheeled power shovel (excavator) will be described. First, the overall configuration of the power shovel 1 will be described with reference to Figs. 1 and 2. As shown in the drawings, the power shovel 1 comprises a traveling body 10 configured to be able to travel, and a water tank mounted on the top of the traveling body 10. It comprises a rotating body 20 that is provided so as to be able to rotate horizontally, and a shovel device 30 provided at the front of the rotating body 20.

[0025] The running vehicle 10 is configured with left and right front wheels 12 and left and right rear wheels 13 mounted on a running vehicle frame 11. Either or both of the front wheels 12 and rear wheels 13 are driven to rotate by a hydraulic traveling motor (not shown), enabling the vehicle to travel. The front wheels 12 are steered by a steering device (not shown). The running vehicle 10 can travel in a desired direction at a desired speed by controlling the rotational drive of the hydraulic traveling motor and steering the front wheels 12 by the steering device. A blade 15 is provided at the front of the running vehicle frame 11 so as to be able to swing up and down. Outriggers 17 that can extend downward are provided at the rear of the running vehicle frame 11, and the outriggers 17 can be extended downward to stably support the vehicle body when working using the shovel device 30.

[0026] A rotating body 20 is provided on the upper part of the running body frame 11 so as to be rotatable via a rotating mechanism (not shown). The rotating body 20 includes a rotating body body 21 that is rotated by the rotating mechanism, and an operator's cabin 22 attached to the rotating body body 21, and an operator can ride in the operator's cabin 22 to travel and operate the power shovel 1. As shown in FIG. 2 , an engine installation space 26 covered by an engine cover 25 is provided inside the rear part of the rotating body body 21, and an engine EG is mounted in this engine installation space 26.

[0027] The shovel unit 30 provided at the front of the revolving unit 20 is configured to have a boom 31 attached to the front of the revolving unit body 21 so as to be able to swing up and down (raise and lower), an arm 32 attached to the tip of the boom 31 so as to be able to swing up and down (bend and extend), and a bucket 34 attached to the tip of the arm 32 so as to be able to swing up and down (bend and extend) via a link mechanism 33 provided at the tip of the arm 32. The shovel unit 30 further has a boom cylinder 31a for raising and lowering the boom 31, an arm cylinder 32a for bending and extending the arm 32, and a bucket cylinder 34a for bending and extending the bucket 34 via the link mechanism 33.

[0028] The engine cover 25 can be opened and closed between a closed position that covers the engine installation space 26 as shown in Fig. 1 and an open position that exposes the engine installation space 26 as shown in Fig. 2. As described above and as shown in Fig. 2, the engine EG is mounted in the engine installation space 26. As shown in Fig. 3, the engine EG includes an engine body 40 having a flywheel 43 as an output member, and a muffler 45 is provided above the engine body 40 to introduce exhaust gas from the engine and reduce exhaust noise. An engine exhaust pipe device 50 is provided that is connected to an outlet portion 45a of the muffler 45 and has a moisture removal function. The engine cover 25 is formed with an opening 28 that allows exhaust gas from the engine exhaust pipe device 50 to be discharged to the outside.

[0029] As shown in Figures 4 and 5, the engine exhaust pipe device 50 includes a flange portion 51 connected to the outlet portion 45a of the muffler 45 with bolts, an inlet pipe 53 joined to the flange portion 51, a swirl-flow pipe 60 joined to the inlet pipe 53 and reinforced with a reinforcing member 67, and an outlet pipe 55 joined to the swirl-flow pipe 60. As shown in Figure 5(a), which shows a cross section taken along arrow AA in Figure 4(b), and Figure 5(b), which shows a cross section taken along arrow BB, the inlet pipe 53 has an inlet opening 53a penetrating the flange portion 51 on the inlet side and an outlet opening 53b on the outlet side that communicates with the internal space 64 of the swirl-flow pipe 60. Therefore, exhaust gas from the muffler 45 is introduced into the inlet pipe 53 through the inlet opening 53a, passes through the inlet pipe 53, and flows into the internal space 64 of the swirl-flow pipe 60 through the outlet opening 53b. As shown in FIG. 7, which shows a cross section taken along the arrow DD in FIG. 4(d), the inlet pipe 53 intersects with and is joined to an eccentric position relative to the center of the pipe body 61 of the swirl flow pipe 60.

[0030] The swirl flow pipe 60 has a hollow cylindrical pipe body 61, the cylindrical outer periphery of which is joined to the tip of the inlet pipe 53, with the cylindrical axis of the pipe body 61 facing obliquely (see FIGS. 4(c), 4(d), 5, and 6). The upper end of the obliquely oriented pipe body 61 is covered by an upper end cap 62 extending obliquely relative to the cylindrical axis of the pipe body 61, and the lower end is covered by a disk-shaped lower end cap 63 extending perpendicular to the cylindrical axis of the pipe body 61. A cylindrical internal space 64 is formed between the cylindrical inner periphery of the pipe body 61, the upper end cap 62, and the lower end cap 63. A small drain hole 61a is formed through the lower part of the lower end of the pipe body 61, and a drain pipe 65 is attached to and connected to this small drain hole 61a.

[0031] As shown in Figure 5 and further shown in Figure 6, which is a cross section taken along arrow CC in Figure 4(d), outlet pipe 55 extends concentrically with swirl flow pipe 60 and penetrates and is attached to upper end lid 62. The inlet side portion of outlet pipe 55 projects into internal space 64, with inlet end opening 55a facing lower end lid 63, and the outlet side portion protrudes outward, with outlet end opening 55b opening diagonally upward and outward. As shown in Figure 1, outlet end opening 55b faces opening 28 of engine cover 25, and engine exhaust gas discharged from outlet end opening 55b is discharged to the outside through opening 28.

[0032] The engine exhaust pipe device 50 configured as described above is attached to the outlet portion 45a of the muffler 45 via the flange portion 51, and engine exhaust gas that passes through the muffler 45 flows into the inlet pipe 53. The inlet engine exhaust gas passes through the inlet pipe 53 and flows into the internal space 64 of the pipe body 61 of the swirl-flow pipe 60. Because the inlet pipe 53 is joined at an eccentric position relative to the pipe body 61 and the outlet pipe 55, the inlet engine exhaust gas forms a swirling flow along the cylindrical inner circumferential surface of the pipe body 61, as shown by arrow Z1 in FIGS. 5 to 7. This swirling flow hits the obliquely extending upper end lid 62, becomes a swirling flow that flows toward the lower end, hits the lower end lid 63, turns back, and enters the outlet pipe 55 from the inlet end opening 55a as shown by arrow Z2, and is then released to the outside from the outlet end opening 55b.

[0033] As shown in Figure 7, outlet opening 53b at the upper end of inlet pipe 53 is formed at an angle. In this state, as shown in the figure, the open end face of outlet opening 53b approaches outlet pipe 55 on the left side in Figure 7, restricting the opening area, and the right side is open widely. As a result, most of the engine exhaust passes through the right side of outlet opening 53b and flows into internal space 64 on the right side of pipe body 61 in Figure 7, efficiently generating a swirling flow.

[0034] As shown in Fig. 8, outlet opening 53b' at the upper end of inlet pipe 53 may be formed so as to be inclined obliquely in the opposite direction to that shown in Fig. 7. When outlet opening 53b' is formed in this manner, the open end face of outlet opening 53b' is closer to outlet pipe 55 on the left side in Fig. 8, limiting the opening area, and the right side is wider open. As a result, most of the engine exhaust flows from outlet opening 53b' through the right side in Fig. 8 into internal space 64 of pipe main body 61, enabling more efficient generation of a swirl flow.

[0035] 7 and 8, the tips of outlet openings 53b, 53b' do not have to be inclined, and the outlet openings may be located in positions facing the space to the right of outlet pipe 55. In this way, engine exhaust gas flows into the space to the right of outlet pipe 55, allowing for efficient generation of a swirling flow.

[0036] In this way, the engine exhaust gas becomes a swirling flow along the cylindrical inner peripheral surface of the pipe body 61 within the internal space 64 of the swirling flow pipe 60, and centrifugal force corresponding to the swirling flow acts on the engine exhaust gas. Because the water droplets and moisture contained in the engine exhaust are heavier than the gas components of the exhaust, they are pressed against and adhere to the cylindrical inner circumferential surface of the pipe body 61 by centrifugal force, forming a water droplet flow. The swirling flow of the engine exhaust hits the upper end cover 62 and becomes a swirling flow flowing downward, so the water droplet flow flows toward the lower end while adhering to the cylindrical inner circumferential surface of the pipe body 61. When the water droplet flow reaches the small water drain hole 61a at the bottom of the lower end of the pipe body 61, it passes through this small water drain hole 61a and then through the water drain pipe 65 to be discharged downward. Note that although the water drain pipe 65 is configured to open downward to allow the water droplet flow to fall onto the road surface, a storage tank connected to the water drain pipe 65 may be provided to store the water droplet flow in the storage tank and periodically disposed of.

[0037] As a result, water droplets and moisture contained in the engine exhaust gas are separated into a water droplet flow and discharged through the water drain pipe 65, and the moisture-free exhaust gas passes through the outlet pipe 55 and is discharged from its outlet end opening 55b, and is then discharged to the outside through the opening 28 in the engine cover 25. The moisture in the engine exhaust gas contains pollutants, but these pollutants are contained in the water droplet flow and are discharged through the water drain pipe 65, so that purified exhaust gas that is free of water and pollutants is discharged to the outside through the outlet pipe 55 and the opening 28 in the engine cover 25. This prevents the moisture, water droplets, and pollutants contained therein from being discharged together with the engine exhaust gas and polluting the surroundings.

[0038] Another embodiment of an engine exhaust pipe device to which the present invention is applied will be described with reference to Figures 9 and 10. This engine exhaust pipe device 70 includes a flange portion 71 that is bolted to the outlet portion 45a of a muffler 45, an inlet pipe 73 joined to the flange portion 71, a swirl flow pipe 80 joined to the inlet pipe 73, and an outlet pipe 75 joined to the swirl flow pipe 80. The inlet side of the inlet pipe 73 is joined to the flange portion 71 and has an inlet opening 73a that penetrates the flange portion 71. The upper end of the inlet pipe 73, which is the outlet side, is joined to the lower end of the swirl flow pipe 80 and communicates with an internal space 83 of the swirl flow pipe 80. Therefore, exhaust gas from the muffler 45 flows from the inlet opening 73a through the inlet pipe 73 and into the internal space 83 of the swirl flow pipe 80.

[0039] Swirl flow pipe 80 is a hollow cylindrical member (main body member defined in the claims) that has a cylindrical internal space 83 that extends vertically, with a swirl flow converter 85 provided in the vertical middle section. Therefore, internal space 83 is divided by swirl flow converter 85 into a lower space 83a (inlet space defined in the claims) and an upper space 83b (outlet space defined in the claims). Swirl flow converter 85 consists of a plurality of swirl vanes 85a joined to the inner circumferential surface of swirl flow pipe 80, and a cylindrical central member 85b joined to the inner circumferential ends of swirl vanes 85a. When exhaust gas from muffler 45 flows from inlet opening 73a through inlet pipe 73 into lower space 83a of swirl-flow pipe 80, the exhaust gas passes through swirl-flow converter 85 and flows into upper space 83b, where it is converted into a swirling flow by the action of swirl vanes 85a and flows into upper space 83b. A capturing groove 81 that extends vertically and has a V-shaped cross section perpendicular to the cylindrical axis is formed in the cylindrical inner surface that forms cylindrical internal space 83 of swirl-flow pipe 80. A small drainage hole is formed through the lower end surface of swirl-flow pipe 80 opposite the lower end of capturing groove 81, and drainage pipe 77 is attached to this small drainage hole.

[0040] The outlet pipe 75 extends concentrically with the upper end surface of the swirl flow pipe 80 and is attached so as to communicate with the interior space 83. The inlet side portion of the outlet pipe 75 protrudes slightly into the upper space 83b, and the outlet side portion protrudes outward, with an open upper end. This upper end opening 75b faces the opening 28 of the engine cover 25 shown in Figure 1, and engine exhaust gas discharged from the upper end opening 75b of the outlet pipe 75 is discharged to the outside through the opening 28.

[0041] The engine exhaust pipe device 70 configured as above is connected to the muffler 4 via the flange portion 71. The muffler 45 is attached to the outlet portion 45a of the muffler 45, and the engine exhaust gas that passes through the muffler 45 flows into the inlet pipe 73. The inlet engine exhaust gas passes through the inlet pipe 73 and flows into the lower space 83a of the swirl flow pipe 80. The engine exhaust gas then flows from the lower space 83a through the swirl flow converter 85 to the upper space 83b. At this time, the flow of the engine exhaust gas is converted into a swirl flow by the swirl vanes 85a and flows into the upper space 83b. The engine exhaust gas then passes through the outlet pipe 75 and is released to the outside.

[0042] As described above, the engine exhaust gas is converted into a swirling flow as it passes through the swirling flow converter 85 from the lower space 83a in the swirling flow pipe 80 and flows into the upper space 83b. Therefore, in the upper space 83b, centrifugal force corresponding to the swirl acts on the engine exhaust gas. This centrifugal force causes the water droplets and moisture contained in the engine exhaust gas to be pressed against and adhere to the cylindrical inner circumferential surface of the swirling flow pipe 80, forming a water droplet flow. The water droplet flow is pushed by the swirling flow and flows circumferentially along the cylindrical inner circumferential surface of the swirling flow pipe 80, entering the capture groove 81. The capture groove 81 extends vertically, and the water droplet flow that enters the capture groove 81 flows downward due to gravity and is discharged downward through the drain pipe 77. While the drain pipe 77 is configured to open downward to allow the water droplet flow to fall onto the road surface, a storage tank connected to the drain pipe 77 may be provided to store the water droplet flow in the storage tank and periodically discard it.

[0043] As a result, water droplets and moisture contained in the engine exhaust gas are separated into a water droplet flow and discharged through the water drain pipe 77, while water-free exhaust gas is discharged through the outlet pipe 75 and then discharged to the outside through the opening 28 in the engine cover 25. The moisture in the engine exhaust gas contains pollutants, but these pollutants are contained in the water droplet flow and discharged through the water drain pipe 77, so purified exhaust gas that is free of water and pollutants is discharged to the outside through the outlet pipe 75 and the opening 28 in the engine cover 25. This prevents the moisture, water droplets and pollutants contained in the engine exhaust gas from being discharged together with the engine exhaust gas and polluting the surrounding area.

[0044] Another embodiment of an engine exhaust pipe device to which the present invention is applied will be described with reference to Fig. 11. This engine exhaust pipe device 170 is configured to include a flange portion 171 that is bolted to the outlet portion 45a of the muffler 45, an inlet pipe 173 joined to the flange portion 171, a swirl flow pipe 180 joined to the inlet pipe 173, and an outlet pipe 175 joined to the swirl flow pipe 180. The inlet side of the inlet pipe 173 is joined to the flange portion 171 and has an inlet opening 173a that penetrates the flange portion 171. The outlet side end of the inlet pipe 173 is joined to the base end side end of the swirl flow pipe 180 and has an outlet opening 173b that communicates with an internal space 184 of the swirl flow pipe 180. Therefore, exhaust gas from muffler 45 is introduced into inlet pipe 173 from inlet opening 173a, passes through inlet pipe 173, and flows into internal space 184 of swirl flow pipe 180 from outlet opening 173b.

[0045] Swirling flow pipe 180 has a hollow cylindrical pipe body 181, the upper end of which is covered by a disc-shaped upper end cover 182, and the lower end is covered by a disc-shaped lower end cover 183. A swirl flow converter 185 is provided inside pipe body 181, and internal space 184 of pipe body 181 is divided into upper end space 184a above swirl flow converter 185 and lower end space 184b below swirl flow converter 185. Swirling flow converter 185 is composed of a central shaft member 185a and swirl vanes 185b provided around it, and when engine exhaust gas flows from upper end space 184a through swirl flow converter 185 to lower end space 184b, the engine exhaust flow is converted into a swirl flow by swirl vanes 185b and flows into lower end space 184b. 11, the pipe body 181 is provided so as to extend at an angle downward from the upper end side to the lower end side. A small drain hole 181a is formed through the lower part of the lower end side of the pipe body 181, and a drain pipe 186 is attached to the outer peripheral surface of the pipe body 181 and connected to this small drain hole 181a.

[0046] The outlet pipe 175 extends concentrically with the lower end cover 183 of the pipe body 181 and penetrates through the lower end cover 183. The inlet side portion of the outlet pipe 175 projects into the lower end space 184b, with the inlet end opening 175a facing the swirl flow converter 185, and the outlet side portion protrudes outward, with the outlet end opening 175b opening diagonally upward and outward. This outlet end opening 175b faces the opening 28 of the engine cover 25 shown in Figure 1, and engine exhaust gas discharged from the outlet end opening 175b is discharged to the outside through the opening 28.

[0047] The engine exhaust pipe device 170 configured as described above is attached to the outlet portion 45a of the muffler 45 via the flange portion 171, and the engine exhaust gas that passes through the muffler 45 flows into the inlet pipe 173. The inlet engine exhaust gas passes through the inlet pipe 173 and flows into the upper space 184a of the pipe body 181 of the swirl flow pipe 180. The engine exhaust gas then flows from the upper space 184a through the swirl flow converter 185 to the lower space 184b. At this time, the engine exhaust gas flow is converted into a swirl flow by the swirl vanes 185b and flows into the lower space 184b. The engine exhaust gas then enters the outlet pipe 175 from the inlet end opening 175a and is released to the outside from the outlet end opening 175b.

[0048] In this way, the engine exhaust gas is converted into a swirling flow as it passes from the upper space 184a to the swirling flow converter 185 in the swirling flow pipe 180 and flows into the lower space 184b. As a result, centrifugal force corresponding to the swirl acts on the engine exhaust gas in the lower space 184b, and the water droplets and moisture contained in the engine exhaust gas are pressed against and adhere to the cylindrical inner circumferential surface of the pipe body 181, forming a water droplet flow. Because the swirling flow of the engine exhaust gas flows toward the lower end, the water droplet flow also flows toward the lower end while remaining attached to the cylindrical inner circumferential surface of the pipe body 181. When the water droplet flow reaches the small drain hole 81a at the bottom of the lower end of the pipe body 181, it passes through the small drain hole 181a and then through the water drain pipe 186 to be discharged downward. Although the drain pipe 186 is configured to open downwards to allow the water droplets to fall onto the road surface, a storage tank connected to the drain pipe 186 may be provided to store the water droplets in the storage tank and periodically dispose of them.

[0049] As a result, water droplets and moisture contained in the engine exhaust gas are separated into a water droplet flow and discharged through the water drain pipe 186, and the moisture-free exhaust gas passes through the outlet pipe 175 and is discharged from its outlet end opening 175b, and is then discharged to the outside through the opening 28 in the engine cover 25. The moisture in the engine exhaust gas contains pollutants, but these pollutants are contained in the water droplet flow and are discharged through the water drain pipe 186, so that purified exhaust gas that is free of water and pollutants is discharged to the outside through the outlet pipe 175 and the opening 28 in the engine cover 25. This prevents the moisture, water droplets, and pollutants contained therein from being discharged together with the engine exhaust gas and polluting the surroundings.

[0050] The above has described the case where the present invention is applied to a power shovel, but the present invention can also be similarly applied to other work vehicles equipped with an engine, such as a shovel loader, and similar effects can be obtained. [Explanation of symbols]

[0051] 1 Power shovel 10 Running body 20 Swing unit 25 Engine cover 30 Excavator Equipment EG Engine 40 Engine body 45 Muffler 50 engine exhaust pipe device 51 flange portion 53 Inlet pipe 55 Outlet pipe 60 Swirl flow pipe 65 Drain pipe 70 engine exhaust pipe device 71 flange portion 73 Inlet pipe 75 Outlet pipe 80 Swirl flow pipe 85 Swirl flow converter 86 Drain pipe

Claims

1. An engine exhaust pipe device that is connected to an exhaust outlet of an engine in a work vehicle equipped with the engine, an inlet exhaust pipe member connected to an exhaust outlet of the engine and having an inlet-side exhaust passage therein; a swirl flow generating device that is connected to the inlet-side exhaust passage and converts the engine exhaust gas introduced thereinto into a swirl flow; an outlet exhaust pipe member having an outlet-side exhaust passage that discharges engine exhaust gas discharged from the swirl flow generating device to the outside, The swirl flow generating device includes a main body member having a cylindrical internal space through which a swirl flow generated by converting engine exhaust gas flows, and a drain hole provided so as to open into the cylindrical internal space, the inlet exhaust pipe member is connected to the main body member at one axial end side of the cylindrical internal space, the inlet-side exhaust passage of the inlet exhaust pipe member extends in a direction along a plane intersecting a central axis of the cylindrical internal space and is connected eccentrically with respect to the central axis, and engine exhaust passing through the inlet-side exhaust passage and flowing into the cylindrical internal space forms a swirling flow within the cylindrical internal space, the outlet exhaust pipe member projects from one end of the main body member into the cylindrical internal space and extends toward the other end of the cylindrical internal space, The engine exhaust gas that has become a swirling flow at one end side of the cylindrical internal space moves to the other end side within the cylindrical internal space, flows into the outlet exhaust pipe member, and is discharged, An engine exhaust pipe device characterized in that the centrifugal force generated by the swirling flow of engine exhaust in the cylindrical internal space causes moisture contained in the engine exhaust to adhere to the inner surface that forms the cylindrical internal space, turning it into water droplets, and the water droplets are discharged to the outside through the drain hole.

2. one end of the cylindrical internal space is covered by a one end lid extending obliquely, and the inlet exhaust pipe member is connected to the main body member at a position facing the one end lid, 2. The engine exhaust pipe device according to claim 1, wherein engine exhaust passing through the inlet-side exhaust passage and flowing into the cylindrical internal space forms a swirling flow within the cylindrical internal space, and is pushed along the obliquely extending direction by hitting the one-end-side lid, thereby flowing to the other end side of the cylindrical internal space.

3. The cylindrical internal space of the main body member is provided so as to slope obliquely downward from the one end lid toward the other end, 3. The engine exhaust pipe device according to claim 2, wherein the drain hole is open at the other end of the cylindrical internal space.

4. An engine exhaust pipe device that is connected to an exhaust outlet of an engine in a work vehicle equipped with the engine, an inlet exhaust pipe member connected to an exhaust outlet of the engine and having an inlet-side exhaust passage therein; a swirl flow generating device that is connected to the inlet-side exhaust passage and converts the engine exhaust gas introduced thereinto into a swirl flow; an outlet exhaust pipe member having an outlet-side exhaust passage that discharges engine exhaust gas discharged from the swirl flow generating device to the outside, the swirl flow generating device comprises a main body member having an internal space extending vertically, the lower end of which is connected to the inlet-side exhaust passage and the upper end of which is connected to the outlet-side exhaust passage; a swirl flow converter provided in a vertically intermediate portion of the internal space; and a drain hole provided so as to open into the internal space, the internal space is partitioned by the swirl flow converter into an inlet-side space connected to the inlet-side exhaust passage and located on a lower side, and an outlet-side space connected to the outlet-side exhaust passage and located on an upper side, The flow of engine exhaust passing through the inlet-side exhaust passage and flowing into the inlet-side space is converted into a swirl flow by the swirl flow converter and flows into the outlet-side space, the internal space is formed as a cylindrical space extending upward from the inlet side space through the swirl flow converter toward the outlet side space, A capture groove is formed on the inner circumferential surface of the internal space, extending vertically from the outlet-side space to the inlet-side space, The drain hole is formed so as to open into the inlet-side space, An engine exhaust pipe device characterized in that the centrifugal force generated by the swirling flow of the engine exhaust in the outlet side space causes the moisture contained in the engine exhaust to adhere to the inner surface forming the outlet side space, turning it into droplets, which then flow into the inlet side space through the capture groove and are discharged to the outside through the drain hole.

5. 5. The engine exhaust pipe device according to claim 4, wherein the drain hole is formed so as to open at a lower end of the trapping groove within the inlet space.

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