JP2000034742A - Exhauster for construction machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a soot stain of respective apparatuses in an engine room by arranging a capturing means for capturing droplets flowing down on the inner wall surface of the tail pipe end part opposed to the delivery pipe end part of a noise eliminator in the expansively opening shape part of the tail pipe end part. SOLUTION: Rainwater infiltrates from the upper opening end 32a of a tail pipe 32 installed through a bracket 33 to blow off exhaust gas to outside air so as to penetrate through a through hole 31 of an engine cover. Droplets of the infiltrated rainwater flow down to the expansively opening shape part 32A by going along the inner wall surface of the tail pipe 32, and contains soot of exhaust gas. The flowing-down droplets are also captured in a space 34 of a pocket member 35, and exhausted outside an engine room through piping 38 after being introduced to the piping 38 through an adapter 37 from the opening part 36 to thereby prevent a soot stain of the outside surface of respective apparatuses and a turning body in the engine room.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust system for a construction machine, in which the end of a discharge pipe is inserted into the expanded shape of a tail pipe to improve the cooling efficiency of an engine room by using an ejector effect. More specifically, the present invention relates to an exhaust device for a construction machine that can prevent soot contamination on each device in an engine room and an outer surface of a revolving structure.

[0002]

2. Description of the Related Art A revolving structure of a construction machine, for example, a hydraulic shovel, is usually covered with a cover, and an engine mounted on a rear portion of the revolving structure and auxiliary equipment related to the engine are provided with an engine in the cover. Located in the room. In this type of construction machine, in order to cool the engine and the auxiliary equipment, air introduced through an intake hole provided on one side of the cover is passed by a cooling fan to a heat exchanger such as a radiator or an oil cooler. After that, the air is further passed to the sides of the engine and the hydraulic pump, and is discharged to the outside through an exhaust hole provided on the other side of the cover. For example, Japanese Patent Application Laid-Open No. 9-12 / 1990
As shown in FIG. 3 of Japanese Patent No. 5957, by utilizing the ejector effect by the flow velocity when the exhaust gas of the engine is externally discharged from the exhaust pipe, the air in the engine room is sucked to induce an upward flow. In some cases, the cooling efficiency in the engine compartment is improved.

In recent years, from the viewpoint of maintenance convenience, a muffler for silencing exhaust gas has been arranged above the engine, and a portion of the cover for covering the engine room, which is located above the engine and the muffler, can be opened and closed. There is something with an engine cover. In this case, the discharge pipe connected to the muffler is disposed so as to penetrate a through hole provided in the engine cover. Must have a relatively large opening area. However, in this case, there is a problem in that noise generated by the engine and its accessories in the engine room is likely to leak outside through the through hole. Therefore, in order to solve this, the discharge pipe is separated into a discharge pipe fixed to the muffler and a tail pipe fixed to the engine cover, and the end of the tail pipe on the muffler side is expanded, so that the discharge pipe is Arrangements have been proposed in which the end is arranged to be inserted into the flared shape of the tailpipe. In the above configuration, by inserting and disposing the end of the discharge pipe in the expanded shape of the tail pipe,
The air outside the discharge pipe is sucked into the tail pipe by using the ejector effect by the flow velocity when the exhaust gas from the discharge pipe flows into the tail pipe. This induces cooling air that cools around the muffler, thereby improving the cooling efficiency of the engine compartment.

[0004]

In the above prior art, the cooling efficiency in the engine compartment is improved by utilizing the ejector effect caused by the flow velocity when the exhaust gas from the discharge pipe flows into the tail pipe. Further, by having a structure separated into the discharge pipe and the tail pipe, the opening and closing operation of the engine cover is ensured without providing an opening in the engine cover.

However, in the above prior art, the inner diameter of the lower end of the expanded shape of the tail pipe is considerably larger than the outer diameter of the end of the discharge pipe due to the structure in which the end of the discharge pipe is inserted and arranged in the expanded shape of the tail pipe. large. Therefore, when rain falls during construction equipment non-operation and rainwater enters from the upper open end of the tailpipe, the droplets flow down the inner wall of the tailpipe and flow down to the expanded shape on the muffler side. From the lower end of the expanded shape, it drops into the engine room through the outside of the discharge pipe. At this time, since soot of exhaust gas adheres to the inner wall surface of the tail pipe at the time of the operation of the construction machine, the dripped droplet contains the soot, which causes a new problem of soiling each device in the engine room with the soot. Also, as described above, part of the liquid droplets flowing down from the upper open end of the tail tube into the expanded shape may be uneven depending on the inner wall surface shape of the tail tube, the strength of the blowing wind, the amount of the liquid droplet, and the like. Before reaching the lower end of the expanded shape, it may drop from the inlet or the intermediate portion of the expanded shape, enter the discharge pipe, and remain in the muffler as a soot-containing liquid film. In this case, when the engine is driven when the operation of the construction machine is resumed, there is also a problem that the liquid film in the muffler rides on the exhaust gas and scatters from the opening end of the tailpipe, so that the region near the tailpipe on the outer surface of the revolving body is stained with soot. is there.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an exhaust system for a construction machine in which the end of a discharge pipe is inserted into an expanded shape of a tail pipe to improve the cooling efficiency of the engine chamber by utilizing an ejector effect. It is an object of the present invention to provide an exhaust device for a construction machine which can prevent soot contamination on the outer surface of the revolving unit and the devices.

[0007]

In order to achieve the above-mentioned object, the present invention relates to a muffler connected to an engine of a construction machine, wherein a discharge pipe end is formed by expanding a tail pipe end facing the discharge pipe end. In the exhaust device of a construction machine that is disposed in the exhaust pipe and that discharges exhaust gas discharged from the discharge pipe into the tail pipe and discharges the exhaust gas to outside air, the trapping means that captures droplets flowing down the inner wall surface of the tail pipe includes An exhaust device for a construction machine, wherein the exhaust device is provided in an expanded shape of a pipe end. If there is rainfall when construction equipment is not working, the rainwater that has entered from the upper open end of the tailpipe travels down the inner wall of the tailpipe and flows down to the muffler-side expanding shape as droplets, including soot adhering to it. Will come
In the present invention, by catching the liquid droplets flowing down by the catching means, droplets containing soot pass through the outside of the discharge pipe and drip into the engine room, thereby contaminating each device in the engine room,
It is possible to prevent the intrusion into the discharge pipe, the accumulation in the muffler, and the scattering of the next time the engine is driven, thereby contaminating the outer surface of the revolving body. Also, at this time, by providing the catching means in an expanded shape at the end of the tail pipe, the flow of the exhaust gas flowing into the tail pipe from the discharge pipe is not obstructed.

Preferably, the capturing means includes a projecting member which is provided so as to protrude inward from the inner wall surface of the expanded shape and which introduces and captures the droplet between the inner wall surface.

[0009] Preferably, a discharging means for discharging the droplets captured by the capturing means is provided. This makes it possible to sequentially discharge the droplets captured by the capturing unit to the outside of the capturing unit, so that even in the case of heavy rain, it is ensured that the droplets accumulate in the capturing unit and overflow. Can be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the present invention is applied to a hydraulic excavator will be described below with reference to FIGS.

FIG. 1 shows a hydraulic excavator to which the present invention is applied. A hydraulic excavator 1 includes a traveling body 2, a revolving body 3 rotatably mounted on the upper part of the traveling body 2, and a revolving body. 3 is provided with an articulated front device 4 rotatably connected to the vertical direction.

The running body 2 has crawler tracks 2a on the left and right as running means, and these crawler tracks 2a are driven by the driving force of a left / right running motor (not shown). You. The revolving superstructure 3 has an operator's cab 5 located on the front left side, and an engine compartment 6 in which an engine (not shown, see FIG. 2 to be described later) is arranged horizontally behind the operator's cab 5. And a counter weight 7 located further rearward of the engine compartment 6 to maintain weight balance. A revolving motor (not shown) is provided at the center of the revolving unit 3 so that the revolving unit 3 and the front device 4 are revolved with respect to the traveling unit 2. The front device 4
Is a boom 4a rotatably coupled to the revolving unit 3.
And an arm 4b rotatably connected to the boom 4a.
And a bucket 4 rotatably coupled to the arm 4b.
c, the boom 4a and the arm 4
b and the bucket 4c are respectively connected to the boom cylinder 8
a, the arm cylinder 8b, and the bucket cylinder 8c.

The boom cylinder 8a, the arm cylinder 8b, the bucket cylinder 8c, and the driving devices (hydraulic actuators) such as the turning motor and the left / right running motor are not described in detail. But,
It is driven by a configuration known as a hydraulic drive. That is, a control valve that responds to an operation lever operation of an operator in the cab 5 by hydraulic oil from a hydraulic pump (not shown, see FIG. 2 described later) driven by an engine in the engine room 6. The hydraulic actuators are supplied to the above-described hydraulic actuators via a device (not shown), and the hydraulic actuators are driven accordingly.

In this specification, when the revolving superstructure 3 is at the position shown in FIG. 1, the front device 4 side (left side in FIG. 1) is referred to as the front or the front side, and the counterweight 7 side (FIG. 1). 1 right side) is called the rear side or the rear side. The left-right direction when the front-rear direction is determined in this way is simply referred to as a left side and a right side.

FIG. 2 is a cross-sectional view taken along the line AA in FIG. 1 showing the internal structure of the engine compartment 6 provided with an embodiment of the exhaust device of the present invention. The same reference numerals indicate the same parts. In FIG. 2, the cover 9
A vibration damping device 1 is mounted on a main frame 10 which forms a foundation lower structure of the revolving superstructure 3 in an engine room 6 whose periphery is covered with the vibration damping device 1.
1, an engine 12 is provided, and exhaust gas from the engine 12 is guided to a muffler 13 as a muffler.

The portion of the cover 9 located above the engine 12 and the muffler 13 is an openable and closable engine cover 9a forming a substantially box-shaped lid. One side of the engine cover 9a is attached to a fixed side of the cover 9 so as to be openable and closable by a hinge 14, thereby facilitating maintenance. Also the engine cover 9
On the other side of “a”, there is provided a lock 15 for hooking the engine cover 9 a to the fixed side of the cover 9.

The driving force of the crankshaft 16 of the engine 12 is determined by the V
The power is transmitted to the auxiliary rotation shaft 20 via the belt 19. As a result, the fan 21 which is an axial fan rotates, and the cooling air P
1, P2 is induced, and so-called suction type engine cooling is performed. That is, the cooling air P1 is
An oil cooler 23 which is sucked into the engine chamber 6 from an intake hole 22 provided on the right side of the engine and cools hydraulic oil (hydraulic oil) supplied to each of the hydraulic actuators from a hydraulic pump (described later); Heat is exchanged by a radiator 24 to which the cooling water 12 is circulated and supplied, and flows into the fan 21 via a shroud 25 fixed to the radiator 24 in order to improve the suction efficiency of the fan 21. Thereafter, the air flows out of the fan 21 and flows around the engine 12 to cool it, and then flows out of the engine room 6 through the exhaust holes 26 provided in the left side portion and the lower portion of the cover 9.
After the cooling air P2 is sucked into the engine room 6 from the intake hole 22, the cooling air P2 passes through an upper space in the engine cover 9a and cools the periphery to some extent, and is formed on the left end surface of the engine cover 9a. The gas flows out from the exhaust hole 27. A hydraulic pump 28 connected to the engine 12 via a gear mechanism (not shown) and driven by the driving force of the engine 12 to supply hydraulic oil to each hydraulic actuator is provided on a side of the engine 12 opposite to the fan 21. I have. A water pump (not shown) for circulating engine cooling water to the radiator 24 is connected to a side of the auxiliary rotation shaft 20 opposite to the fan 21.

The muffler 13 is fixed to a side surface of the cover 9 via a bracket 29. FIG. 3 is a side sectional view from the right side showing a detailed structure of the vicinity of the muffler 13 of the engine room 6 provided with the embodiment of the exhaust device of the present invention shown in FIG. Those indicate the same parts. In FIG. 3, the right side corresponds to the front side, and the left side corresponds to the rear side. In FIG. 3, the exhaust gas Q from the engine 12
Is guided from the exhaust manifold 12A of the engine 12 to the exhaust pipe 30 fixed to the upper part of the engine 12 via the bracket 29, as shown by the arrow.
It flows into the muffler main body 13b through the inlet pipe 13a of the muffler 13 fitted to 0. Then, the exhaust gas Q passes through the inside of the muffler body 13b, is silenced, and has a discharge pipe 13c projecting upward (downstream side) of the muffler body 13b.
Is discharged to the outside of the muffler 13. At this time, a tail pipe 32 for discharging the exhaust gas Q to the outside air is attached via a bracket 33 so as to pass through the through hole 31 of the engine cover 9a. The vicinity of the lower end of the tail pipe 32 is an expanded portion 32A, and the above-described muffler discharge pipe 13c is arranged to be inserted into the expanded shape. Thus, the exhaust gas Q discharged from the discharge pipe 13c flows into the tail pipe 32 and is discharged to the outside air via the tail pipe 32. Then, using the ejector effect due to the flow rate of the exhaust gas Q at this time (= converting the velocity energy of the high-speed fluid into pressure energy and sucking another fluid), the discharge pipe 13 is used.
c Inhale outside air into the tail tube 32. As a result, the cooling air R that mainly cools the periphery of the muffler 13 is induced to reinforce the cooling air P2 passing through the vicinity of the muffler 13 (see FIG. 2). The cooling in the vicinity of the muffler 13 is promoted, and the cooling efficiency in the engine room 6 is improved.

FIG. 4 is an enlarged vertical sectional view showing a detailed structure in the vicinity of a connection portion between the tail pipe 32 and the muffler discharge pipe 13c, which is a main part of one embodiment of the exhaust device of the present invention shown in FIG. 3 have the same reference numerals. In FIG. 4, a pocket member 35 is provided which protrudes inward from the inner wall surface of the tail tube widening shape portion 32A and forms a substantially annular space 34 with the inner wall surface. This pocket member 35
Has a substantially horizontal bottom portion 35a and a side surface portion 35b substantially parallel to the expanded shape portion 32A, and is configured by, for example, joining these by welding or the like. Also, the bottom 35
An opening 36 for drainage is formed at one position (or a plurality of positions) in the circumferential direction of a, and a pipe 38 such as a hose is connected through an adapter 37 fitted into the opening 36. . This pipe 38 is, as shown in FIG.
It is pulled while being gripped by the attachment 40 provided on the muffler 13 and the engine 12, and its lower end 38 a is exposed downward through the exhaust hole 26 provided on the bottom of the cover 9.

In the above configuration, the pocket member 3
5 is a protruding member that protrudes inward from the inner wall surface of the expanded shape and that introduces and captures droplets between the inner wall surface and a capturing unit that captures droplets flowing down the inner wall surface of the tail tube. Is also configured. In addition, the opening 36, the adapter 37, and the pipe 38 constitute a discharging unit that discharges the droplets captured by the capturing unit.

Next, the operation of the above-described embodiment of the exhaust device of the present invention will be described. The working time and working period of construction machines such as the hydraulic excavator 1 are often long, and when a worker takes a break or finishes working on that day, the engine 1
2 is stopped and left at the work site. Since construction machines such as the hydraulic excavator 1 work outdoors, rainfall is often encountered during such non-work.
In this case, as shown in FIG.
Rainwater may enter from 2a, and the intruded rainwater droplets 39 flow down the inner wall surface of the tail pipe 32 and flow down to the expanded shape portion 32A. At this time, since soot (not shown) of the exhaust gas adheres to the inner wall surface of the tail pipe 32 during the operation of the hydraulic excavator, the droplet 39 flowing down contains soot.

Here, if the pocket member 35 is not provided as in the conventional structure, most of the droplet 39 that has flowed down is discharged from the lower end of the expanded shape portion 32A to the outside of the discharge pipe 13c as indicated by a droplet 39A indicated by a broken line. Then, the liquid drops are dropped into the engine room 6 through the air passage, and each device in the engine room 6 is stained with soot. On the other hand, a part of the droplet 39 that has flowed down to the expanded shape portion 32A depends on the irregularity of the inner wall surface shape of the tail tube 32, the strength of the blowing wind, the amount of the droplet 39, and the like, and the like.
Before reaching the lower end of A, it drops (or scatters) from the entrance or the middle of the expanded shape portion 32A like a droplet 39B shown by a broken line, enters the discharge pipe 13c, and contains soot in the muffler 13. May remain as a liquid film. In this case, when the engine 12 is driven when the operation of the hydraulic excavator 1 is restarted, the liquid film in the muffler 13 rides on the exhaust gas Q and scatters from the tail pipe opening end 32a, so that the region near the tail pipe 32 on the outer surface of the revolving unit 3 is sooted. May get dirty.

However, in the above-described embodiment of the present invention, the provision of the pocket member 35 allows the falling droplet 39 to be captured in the space 34. Thus, it is possible to prevent each device in the engine room 6 from being stained with soot as described above, and to prevent the outer surface of the revolving unit 3 from being stained when the engine 12 is driven next time. Space 34
Droplets 39 captured one after another inside are introduced into the pipe 38 through the opening 36 via the adapter 37, and discharged to the outside of the engine room 6 through the pipe 38. Therefore, even if heavy rain falls, it is possible to reliably prevent the droplets 39 from collecting and overflowing in the space 34. Furthermore, by providing the pocket member 35 in the expanded shape portion 32A, the flow of the exhaust gas Q flowing into the tail pipe 32 from the discharge pipe 13c at the time of work is not hindered. The side surface portion 35b is expanded to the expanded shape portion 32.
By arranging substantially in parallel with A, the original ejector effect is not impaired.

From the viewpoint of reliably catching the droplet 39, the distance L between the expanded shape portion 32A and the pocket member side surface 35b is preferably 10 mm or more, and the height W of the side surface 35b is preferably not less than 10 mm. It is preferable that the upper end position is the same as the upper end of the expanded shape portion 32A. Further, the shape of the pocket member 35 is not limited to the shape shown in FIG. 5. For example, the position of the bottom 35 a is raised as shown in FIG. 6, or the bottom 35 a is inclined as shown in FIG. 7. The cooling air R may be introduced smoothly.

Further, in the above-described embodiment of the present invention, the oil cooler 23 and the radiator 24 are provided as heat exchangers cooled by the cooling air P1. An intercooler for pre-cooling the working air, a condenser for an air conditioner, or the like may be provided. In this case, a similar effect is obtained.

[0026]

According to the present invention, the droplets flowing down by the capturing means are captured, so that the droplets containing soot drips into the engine room and contaminates the various components in the engine room, or accumulates in the muffler and the next time the engine is stopped. It is possible to prevent the revolving body from being scattered at the time of driving and soiling the outer surface of the revolving body.

[Brief description of the drawings]

FIG. 1 is an external perspective view showing a hydraulic shovel to which the present invention is applied.

FIG. 2 is a cross-sectional view taken along a line AA in FIG. 1 showing a structure inside an engine room equipped with an embodiment of the exhaust device of the present invention.

3 is a right side sectional view showing a detailed structure near a muffler of an engine room provided with the embodiment of the exhaust device of the present invention shown in FIG. 2;

FIG. 4 is an enlarged vertical sectional view showing a detailed structure near a connection portion between a tail pipe and a muffler discharge pipe, which is a main part of one embodiment of the exhaust device of the present invention shown in FIG.

FIG. 5 is a diagram for explaining the operation of the embodiment of the exhaust device of the present invention when rainwater enters.

FIG. 6 is a view showing a modification of the pocket member shape in the embodiment shown in FIG. 4;

FIG. 7 is a view showing a modified example of the pocket member shape in the embodiment shown in FIG.

[Explanation of symbols]

1 ... hydraulic excavator, 6 ... engine room, 12 ... engine,
13: muffler (muffler), 13c: discharge pipe (discharge pipe), 32: tail pipe, 32A: expanded shape part, 35: pocket member (projecting member, catching means), 36: opening (discharge means), 37: Adapter (discharge means), 38: Pipe (discharge means), 39: Droplet, Q: Exhaust gas,

Claims (3)

[Claims] An end of a discharge pipe of a silencer connected to an engine of a construction machine is disposed within an expanded shape of an end of a tail pipe facing the end of the muffler, and the exhaust gas discharged from the discharge pipe is discharged from the discharge pipe. In an exhaust device for a construction machine that flows into a tail pipe and discharges to the outside air, a capturing unit that captures droplets flowing down the inner wall surface of the tail pipe,
An exhaust device for a construction machine, wherein the exhaust device is provided in an expanded shape of an end portion of the tail pipe. 2. The exhaust device for a construction machine according to claim 1, wherein said catching means is provided so as to protrude inward from an inner wall surface of said expanded shape, and introduces and captures said droplet between said inner wall surface. An exhaust device for a construction machine, comprising a projecting member. 3. The exhaust device for a construction machine according to claim 1, further comprising a discharge device for discharging the droplets captured by said capture device.