JP7777989B2 - Engine exhaust pipe system - Google Patents

Description

The present invention relates to an engine exhaust pipe device that is installed at the location where engine exhaust is discharged.

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

Such work vehicles include those equipped with a silencer (hereinafter also referred to as a muffler) housed in the engine compartment to reduce exhaust noise from the engine, and 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.) is installed inside the operator's cabin to blow cool and warm air into the operator's cabin, and a compressor that compresses the air conditioning refrigerant and a condenser that condenses the compressed refrigerant are located inside the engine compartment (see, for example, Patent Documents 1 and 2 below).

Patent No. 3920679 Patent No. 4388458

Exhaust from an engine contains moisture (steam), which condenses inside the exhaust pipe and is then discharged to the outside. This moisture is particularly likely to condense immediately after a cold engine start, and this condensed water is then 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 rapid rate, the exhaust is dispersed widely around the exhaust pipe. The water and moisture that is dispersed widely and discharged contains contaminants, which can contaminate the vehicle body and engine covers around the exhaust pipe, as well as buildings and people (workers and passersby) around the work vehicle equipped with this engine.

The present invention was made in consideration of these circumstances, and aims to provide an engine exhaust pipe device that is configured to prevent moisture contained in the exhaust from the engine and the liquid water that results from condensation from being discharged outside the exhaust pipe, thereby preventing contamination of the surrounding area by the contaminants contained in the moisture.

In order to achieve the above-mentioned object, the engine exhaust pipe device of the present invention is an engine exhaust pipe device that is connected to the 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 inside, 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 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 releases the engine exhaust discharged from the swirl flow generating device to the outside, and the swirl flow generating device includes a main body member (e.g., a pipe main body in the embodiments) that has a cylindrical internal space through which the swirl flow generated by converting the engine exhaust flows, and a drain hole that opens into the cylindrical internal space .

The engine exhaust pipe device is further configured so that the inlet exhaust pipe member is connected to the main body member at one axial end 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, so that engine exhaust passing through the inlet-side exhaust passage and flowing into the cylindrical internal space becomes 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, so that the engine exhaust that has become a swirling flow at one end of the cylindrical internal space moves within the cylindrical internal space to the other end and flows into the outlet exhaust pipe member to be discharged, and centrifugal force generated by the swirling flow of the engine exhaust in the cylindrical internal space causes moisture contained in the engine exhaust to adhere to the inner circumferential surface that defines the cylindrical internal space, turning into water droplets which are then discharged to the outside through the drain hole.

Furthermore, in the above engine exhaust pipe device, preferably, one end of the cylindrical internal space is covered by a diagonally extending one end lid, the inlet exhaust pipe member is connected to the main body member at a position opposite the one end lid, and the engine exhaust passing through the inlet exhaust passage and flowing into the cylindrical internal space becomes a swirling flow within the cylindrical internal space and is pushed along the diagonally extending direction by hitting the one end lid, so that it flows to the other end of the cylindrical internal space.

In the above-mentioned engine exhaust pipe device, preferably, the cylindrical internal space of the main body member is formed so as to slope diagonally downward from the one end side cover toward the other end side, and the drain hole is formed and opened at the other end side of the cylindrical internal space.

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 releases the engine exhaust discharged from the swirl flow generating device to the outside, and the lower end side of the swirl flow generating device is connected to the inlet-side exhaust passage. The exhaust manifold comprises a main body member having an internal space extending vertically , both of which have their upper ends connected to the outlet-side exhaust passage, a swirl flow converter provided in the middle of the internal space in the vertical direction , and a drain hole provided so as to open into the internal space, and the internal space is divided by the swirl flow converter into an inlet-side space connected to the inlet-side exhaust passage and located on the lower side , and an outlet-side space connected to the outlet-side exhaust passage and located on the upper side , and 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.

In the above engine exhaust pipe device , the internal space is further formed as a cylindrical space extending upward from the inlet side space through the swirl flow conversion device toward the outlet side space, a capture groove is formed on the inner peripheral surface of the internal space extending vertically from the outlet side space to the inlet side space, and the 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 peripheral 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 drain hole.

Furthermore, in the engine exhaust pipe device, the drain hole is preferably formed so as to open at a lower end of the trapping groove within the inlet space.

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

In the above-described engine exhaust pipe device, it is preferable that the internal space of the main body member comprises a cylindrical space that functions as a swirl flow generating device, and that 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, engine exhaust passing through the inlet-side exhaust passage and flowing 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.

Furthermore, in this engine exhaust pipe device, it is preferable that one end of the cylindrical space is covered by a diagonally extending one-end lid, and the inlet exhaust pipe member is connected to the main body member at a position opposite the one-end lid. 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, hits the one-end lid, and is pushed along the diagonal direction toward the other end of the cylindrical space, allowing the generated swirling flow to flow smoothly toward the outlet exhaust pipe member.

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 diagonally downward from the one end lid toward the other end, and that the drain hole be formed at the other end of the cylindrical space. In this way, the centrifugal force generated by the swirling flow of the engine exhaust causes moisture contained in the engine exhaust to adhere to the inner surface forming the cylindrical space, turning it into water droplets. These water droplets then flow along the diagonally downward slope and can be efficiently discharged from the drain hole formed at the lower end (i.e., the other end).

According to another engine exhaust pipe device of the present invention, a swirl flow generating device includes a main body member having an internal space, a swirl flow converter disposed in a central portion 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. 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 then flows into the outlet space. Therefore, 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 of the outlet space, forming droplets, which are then 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 likely to be discharged from the exhaust pipe to the outside along with the exhaust, polluting the surrounding area; however, the engine exhaust pipe device of the present invention can effectively prevent this problem.

Furthermore, in the above-mentioned 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 thereof, and that the internal space be formed as a cylindrical space extending upward from the inlet-side space through the swirl flow converter toward the outlet-side space. This allows a swirl flow to be effectively generated within the outlet space.

Furthermore, in the above engine exhaust pipe device, it is preferable that a capture groove is formed on the inner peripheral surface forming the cylindrical space, extending vertically from the outlet space to the inlet space, and that the drain hole is formed within the inlet space, opening at the lower end of the capture groove. In this way, water droplets can be effectively captured within the capture groove, and the captured water droplets can flow downward within the capture groove and be smoothly discharged through the drain hole opening at its lower end.

Furthermore, in the above-mentioned engine exhaust pipe device, it is preferable that the internal space in the main body member be formed as a cylindrical space that extends obliquely downward from the inlet space through the swirl flow converter toward the outlet space, and that the drain hole be formed so as to open at the 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.

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. FIG. 2 is a perspective view showing the power shovel with an engine cover open. FIG. 2 is a perspective view of an engine mounted on the power shovel. 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. 5A and 5B are cross-sectional views of the engine exhaust pipe device taken along the line AA and BB, respectively, shown in FIG. 4B. 4(d) is a cross-sectional view of the engine exhaust pipe device taken along the line CC shown in FIG. 4(d) is a cross-sectional view of the engine exhaust pipe device shown in FIG. FIG. 8 is a cross-sectional view corresponding to FIG. 7 showing a modified embodiment of the engine exhaust pipe device. FIG. 10 is an external perspective view showing a different embodiment of an engine exhaust pipe device according to the present invention. 1 is a perspective view showing the exterior of an engine exhaust pipe device according to this embodiment, with a partial cross section. FIG. 4 is a cross-sectional view showing another embodiment of an engine exhaust pipe device according to the present invention.

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 is configured to have a traveling body 10 configured to be able to travel, a rotating body 20 provided above the traveling body 10 so as to be able to rotate horizontally, and a shovel unit 30 provided at the front of the rotating body 20.

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 running hydraulic 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 and at a desired speed by controlling the rotational drive of the running hydraulic motor and steering the front wheels 12 by the steering device. A blade 15 is mounted to the front of the running vehicle frame 11 so that it can swing up and down. Outriggers 17 that can extend downward are mounted to the rear of the running vehicle frame 11, and can extend the outriggers 17 downward to provide stable support for the vehicle when working with the shovel device 30.

A rotating body 20 is provided on the upper part of the running body frame 11 and is rotatable via a rotating mechanism (not shown). The rotating body 20 comprises a rotating body body 21 that is rotated by the rotating mechanism, and a driver's cabin 22 attached to the rotating body body 21. An operator can ride in the driver's cabin 22 to drive and operate the power shovel 1. As shown in Figure 2, an engine installation space 26 covered by an engine cover 25 is located inside the rear of the rotating body body 21, and the engine EG is mounted in this engine installation space 26.

The shovel unit 30, mounted at the front of the rotating unit 20, is composed of a boom 31 attached to the front of the rotating 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. 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.

The engine cover 25 can be moved between a closed position, which covers the engine mounting space 26 as shown in FIG. 1, and an open position, which opens the engine mounting space 26 as shown in FIG. 2. As described above and as shown in FIG. 2, an engine EG is mounted within the engine mounting 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 from the engine and reduce exhaust noise. An engine exhaust pipe device 50 is provided connected to the outlet portion 45a of the muffler 45 and equipped with a moisture removal function. The engine cover 25 is formed with an opening 28 for discharging exhaust from the engine exhaust pipe device 50 to the outside.

As shown in Figures 4 and 5, the engine exhaust pipe device 50 comprises a flange portion 51 bolted to the outlet portion 45a of the muffler 45, 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 arrows A-A in Figure 4(b), and Figure 5(b), which shows a cross section taken along arrows B-B, the inlet pipe 53 has an inlet opening 53a penetrating the flange portion 51 on the inlet side and an outlet opening 53b communicating with the internal space 64 of the swirl-flow pipe 60 on the outlet side. 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 Figure 7, which shows a cross section taken along arrows D-D in Figure 4(d), the inlet pipe 53 intersects with and is joined at an eccentric position relative to the center of the pipe body 61 of the swirl flow pipe 60.

The swirl flow pipe 60 has a hollow cylindrical pipe body 61, the cylindrical outer surface of which is joined to the tip of the inlet pipe 53, with the cylindrical axis of the pipe body 61 oriented at an angle (see Figures 4(c), 4(d), 5, and 6). The upper end of the oriented pipe body 61 is covered by an upper end cap 62 that extends 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 that extends perpendicular to the cylindrical axis of the pipe body 61. A cylindrical internal space 64 is formed by the cylindrical inner surface 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 end of the pipe body 61, and a drain pipe 65 is attached to this small drain hole 61a.

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

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. Engine exhaust gas passing 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 attached eccentrically to the pipe body 61 and the outlet pipe 55, the inlet engine exhaust gas forms a swirling flow along the cylindrical inner surface of the pipe body 61, as shown by arrow Z1 in Figures 5 to 7. This swirling flow hits the obliquely extending upper end lid 62 and becomes a swirling flow flowing toward the lower end. It then 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 released to the outside from the outlet end opening 55b.

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

As shown in Figure 8, the outlet opening 53b' at the upper end of the inlet pipe 53 may be formed so as to be inclined diagonally in the opposite direction to that shown in Figure 7. By forming the outlet opening 53b' in this manner, the opening end face of the outlet opening 53b' is closer to the outlet pipe 55 on the left side in Figure 8, limiting the opening area, while the right side is left more open. As a result, most of the engine exhaust flows from the outlet opening 53b' through the right side in Figure 8 into the internal space 64 of the pipe body 61, allowing for more efficient generation of a swirling flow.

As can be seen from the structure shown and described in Figures 7 and 8, the tips of the outlet openings 53b, 53b' do not have to be inclined, and the outlet openings can be positioned so that they face the space to the right of the outlet pipe 55. In this way, engine exhaust can flow into the space to the right of the outlet pipe 55, efficiently generating a swirling flow.

In this way, the engine exhaust becomes a swirling flow along the cylindrical inner circumferential surface of the pipe body 61 within the internal space 64 of the swirl flow pipe 60, and centrifugal force corresponding to the swirl acts on the engine exhaust. Because the water droplets and moisture contained in the engine exhaust are heavier than the gas components of the exhaust, this centrifugal force causes them to be pressed against and adhere to the cylindrical inner circumferential surface of the pipe body 61, 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 remaining attached to the cylindrical inner circumferential surface of the pipe body 61. When the water droplet flow reaches the small drain hole 61a at the bottom of the lower end of the pipe body 61, it passes through this small drain hole 61a and further through the drain pipe 65 to be discharged downward. Note that although the 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 drain pipe 65 may be provided to store the water droplet flow in the storage tank and periodically dispose of it.

As a result, the water droplets and moisture contained in the engine exhaust are separated into a water droplet flow and discharged through the drain pipe 65, while the moisture-free exhaust 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 contains pollutants, but these pollutants are contained in the water droplet flow and discharged through the drain pipe 65, so purified exhaust 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 in the engine exhaust from being discharged along with the engine exhaust and contaminating the surrounding area.

Another embodiment of an engine exhaust pipe device incorporating the present invention will be described with reference to Figures 9 and 10. This engine exhaust pipe device 70 comprises a flange portion 71 bolted to the outlet portion 45a of the 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 is connected to the 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.

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

The outlet pipe 75 extends concentrically from the upper end surface of the swirl flow pipe 80 and is attached so as to communicate with the internal space 83. The inlet side of the outlet pipe 75 extends slightly into the upper space 83b, while the outlet side protrudes outward and is open at its 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.

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.

As described above, 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 enters the upper space 83b. As a result, centrifugal force corresponding to the swirl acts on the engine exhaust gas within the upper space 83b. This centrifugal force presses the water droplets and moisture contained in the engine exhaust gas against and adheres to the cylindrical inner surface of the swirling flow pipe 80, forming a water droplet flow. The water droplet flow is pushed by the swirling flow in a circumferential direction along the cylindrical inner surface of the swirling flow pipe 80 and enters 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 and periodically dispose of it.

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

Another embodiment of an engine exhaust pipe device to which the present invention is applied will be described with reference to Figure 11. This engine exhaust pipe device 170 comprises 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 end of the inlet pipe 173 is joined to the base end of the swirl flow pipe 180 and has an outlet opening 173b that communicates with the internal space 184 of the swirl flow pipe 180. As a result, exhaust air from the muffler 45 is introduced into the inlet pipe 173 through the inlet opening 173a, passes through the inlet pipe 173, and flows into the internal space 184 of the swirl flow pipe 180 through the outlet opening 173b.

The swirl flow pipe 180 has a hollow cylindrical pipe body 181, the upper end of which is covered by a disc-shaped upper end cap 182, and the lower end is covered by a disc-shaped lower end cap 183. A swirl flow converter 185 is provided inside the pipe body 181, and the internal space 184 of the pipe body 181 is divided into an upper end space 184a above the swirl flow converter 185 and a lower end space 184b below the swirl flow converter 185. The swirl flow converter 185 consists of a central shaft member 185a and swirl vanes 185b provided around it. When engine exhaust gas flows from the upper end space 184a through the swirl flow converter 185 to the lower end space 184b, the engine exhaust flow is converted into a swirl flow by the swirl vanes 185b and flows into the lower end space 184b. As shown in Figure 11, the pipe body 181 extends from the upper end to the lower end at an angle downward. A small drain hole 181a is formed through the lower part of the lower end of the pipe body 181, and a drain pipe 186 is attached to the outer surface of the pipe body 181, connected to this small drain hole 181a.

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 of the outlet pipe 175 protrudes into the lower end space 184b, with the inlet end opening 175a facing the swirl flow converter 185, while the outlet side 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.

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 engine exhaust passing through the muffler 45 flows into the inlet pipe 173. The inlet engine exhaust passes through the inlet pipe 173 and flows into the upper end space 184a of the pipe body 181 of the swirl flow pipe 180. The engine exhaust then flows from the upper end space 184a through the swirl flow converter 185 to the lower end space 184b. At this time, the engine exhaust flow is converted into a swirl flow by the swirl vanes 185b and flows into the lower end space 184b. The exhaust then enters the outlet pipe 175 from the inlet end opening 175a and is released to the outside from the outlet end opening 175b.

In this way, engine exhaust gas is converted into a swirling flow as it passes from the upper space 184a through 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 within the lower space 184b. This centrifugal force presses the water droplets and moisture contained in the engine exhaust gas against and adheres to the cylindrical inner surface of the pipe body 181, forming a water droplet flow. Because the swirling flow of engine exhaust flows toward the lower end, the water droplet flow also flows toward the lower end while remaining attached to the cylindrical inner 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 this 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 and allow the water droplets to fall onto the road surface, a storage tank connected to the drain pipe 186 can be provided to store the water droplets in the storage tank and periodically discard them.

As a result, the water droplets and moisture contained in the engine exhaust are separated into a water droplet flow and discharged through the drain pipe 186, while the moisture-free exhaust 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 contains pollutants, but these pollutants are contained in the water droplet flow and discharged through the drain pipe 186, so purified exhaust 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 in the engine exhaust from being discharged along with the engine exhaust and contaminating the surrounding area.

The above describes the application of the present invention to a power shovel, but the present invention can also be similarly applied to other work vehicles equipped with engines, such as shovel loaders, and similar effects can be obtained.

REFERENCE SIGNS LIST 1 Power shovel 10 Traveling body 20 Swing body 25 Engine cover 30 Shovel device 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 device 86 Drain pipe

Claims (5)

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. 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. 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. 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. The engine exhaust pipe device described in claim 4, characterized in that the drain hole is formed so as to open at the lower end of the capture groove within the inlet-side space.