JP3055385B2 - Engine sound absorber for construction machinery - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine soundproofing device for reducing noise from an engine in a hydraulic shovel and other construction machines.

[0002]

2. Description of the Related Art In construction machines such as hydraulic excavators,
An engine is provided for driving a hydraulic pump and the like, and the engine is mounted on a vehicle body frame at a position rearward of an upper swing body of the vehicle. Further, a counterweight is mounted at a position further behind the mounting portion of the engine.

[0003] When the engine is operated, an extremely loud noise is generated. Therefore, in order to reduce the noise and to protect the engine, the engine is surrounded by a cover member. However, since the counter weight is provided at the rear position of the engine, the rear side is not covered. Further, the cover member is formed separately from the counterweight, and is attached to the vehicle body frame independently of each other.

[0004]

As described above, if there is a gap between the cover member and the counterweight, noise leaks from the gap to the outside. Regardless of the noise leaking upward or to the side, the noise leaking downward is reflected complexly on the ground, and this reflected noise is extremely unpleasant for workers working around the construction machine.

Here, since the counterweight is located at the rearmost part of the vehicle body, its outer surface side affects the turning radius, and therefore, the rear side usually has an arc centered on the turning center. Or a shape close to an arc.
In addition, the height of the counterweight also has a certain dimension from the viewpoint of securing a rear view from the cab. Naturally, the counterweight must have a fixed weight in order to balance the weight with the front working mechanism and exhibit the function of stabilizing the vehicle body. As described above, the counterweight is limited in its outer surface and height, and must have a predetermined weight. Therefore, the surface shape of the inner surface, that is, the surface facing the engine, is determined as follows. It is determined according to whether or not to have weight, and often has a shape with complicated irregularities. On the other hand, the shape of the lower cover portion of the cover member is also designed based on the relationship between the arrangement and shape of the engine.

As described above, in the prior art, since the cover member and the counterweight are formed separately from each other and mounted on the vehicle body frame, a considerably large gap is entirely and partially generated therebetween. I will. In order to prevent noise from leaking from this gap, there is also known a configuration in which a sound absorbing material made of urethane foam or the like is attached to this gap. However, the sound absorbing material cannot attenuate the sound passing through it very efficiently. Therefore, in order to effectively reduce the noise, it is necessary to mount an enormous amount of sound absorbing material in such a wide gap formed between the cover member and the counterweight. Even if a sound absorbing material is attached, the noise reduction effect is not always good.

The present invention has been made in view of the above points, and a gap is generated between the cover accommodating the engine and the counterweight, which are separately mounted on the body frame as separate members. It is unavoidable that the object is to reduce noise by managing the gap.

[0008]

In order to achieve the above-mentioned object, according to the present invention , the lower cover of the cover member is first turned to the counterweight so that the lower portion of the cover member can be moved during operation of the vehicle. It is configured to extend to a position separated only by a distance . Such groups
In addition to this configuration, the present invention further enhances the soundproofing effect.
For this purpose, the following configuration is adopted.
It is assumed that. First, in the first invention, the aforementioned
Of the lower cover and counterweight in addition to the
A packing member made of an elastic member in a gap formed therebetween
Is filled. Ma
According to a second aspect of the present invention, in addition to the above-described configuration, a lower cover is provided.
The distance between the bar and the counterweight is
Separation from the lower cover at the middle in the width direction of the eight
The separation distance is the separation distance at both ends of the counterweight.
The feature is that the length is shortened .

[0009]

From the viewpoint of noise reduction, it is sufficient that no gap is formed between the lower cover and the counterweight of the cover member. However, if the lower cover is configured to contact the counterweight to eliminate the gap between them, after the lower cover is mounted on the body frame, when the counterweight is mounted, it will collide with the lower cover and deform. Or may be damaged. Also, while the vehicle is running or working, the counterweight may move, and at this time, it repeatedly collides with the lower cover, generating noise due to the impact, and deforming due to excessive force being applied. Will happen.

In view of the above, in the present invention, a gap is provided so as not to contact the counterweight and the lower cover, and the gap is minimized by strictly managing the gap. By doing so, leakage of noise to the outside is reduced as much as possible.

Here, in order to minimize the gap between the lower cover and the counterweight, attention has been paid to the counterweight. The counterweight is usually fixed to the vehicle body frame, but the counterweight swings or vibrates while the vehicle is running or working. And, by this swing or vibration, it also moves in the front-rear direction, that is, the direction approaching / separating from the part where the engine is mounted,
The range of motion in this direction is not very large. Therefore, the lower cover is extended in a direction approaching the counterweight, and a gap between the lower cover and the counterweight is provided only within the range of movement of the counterweight. This minimizes gaps
Control. Moreover, the elastic member
Filling with packing material such as sound absorbing material
The sound effect can be further improved. Therefore, this gap
Since the filling amount of the packing material in between may be small,
Packing material can be saved. By the way, the counterway
The range of swing or vibration of the
The left and right sides are larger. So, the lower hippo
Change the gap, counterweight and gap in the width direction.
By doing so, the gap between them is substantially
It can be almost matched to the range of movement of the light.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. First, FIG. 1 shows an entire configuration of a hydraulic shovel as an example of a construction machine. In the figure, reference numeral 1 denotes a lower traveling body, 2 denotes an upper revolving body that is rotatably provided on the lower traveling body 1, and 3 denotes a front working mechanism that performs excavation and the like. A front working mechanism 3 is connected to a front side of the upper swing body 2, and a cab 4 is provided. A machine room 5 in which an engine, a hydraulic pump, a hydraulic oil tank, and the like are mounted is disposed on the rear side, and a counterweight 6 is mounted in a rearmost position.

2 and 3 show the structure of the rear portion of the upper swing body 2. FIG. In the figure, 10 is a main frame, 1
Reference numeral 1 denotes a beam member, and the main frame 10 and the beam member 11 constitute a structure of the upper swing body 2.
The counter weight 6 is fixed to a rear end position of the main frame 10. Reference numeral 12 denotes an engine, and 13 denotes a hydraulic pump. The hydraulic pump 13 is connected to the engine 12. The engine 12 is also installed on the main frame 10. The machine room 5 in which the engine 12 and the like are mounted has a machine room cover 14 for protecting each member.
And is surrounded by the machine room cover 14.

The machine room cover 14 includes left and right side covers 14.
a, 14b, a canopy cover 14c and a lower cover 14d
Having. Although not shown, a front cover is also provided on the front side, that is, on the side facing the cab 4. However, no cover is provided on the rear side, that is, on the side facing the counterweight 6, and the space is open. One side cover 14a of the left and right side covers 14a and 14b is an openable / closable door type, and a portion of the canopy cover 14c which is located above a portion where the engine 12 is disposed is a vertical portion. It can be opened in any direction to enable maintenance and the like.

The lower cover 14d is attached to the main frame 10
And is fixed to the beam member 11 at the rearmost end by welding means, a part of which is a detachable cover portion 14dA, and the detachable cover portion 14dA is fixed with bolts or the like so as to be detachable. It is configured to be fixed to the main frame 10, the beam member 11, and the like using a tool (not shown). The entire lower cover 14d including the detachable cover portion 14dA faces the lower end of the inner surface 6a of the counterweight 6, and the front end thereof has a predetermined gap G with respect to the inner surface 6a of the counterweight 6. It extends to the position where it is formed.

Here, the counterweight 6 is used to balance the weight of the entire vehicle body during the operation by the front working mechanism 3 so as to stabilize the counterweight. Therefore, the weight and the position of the center of gravity are the same as those of the entire hydraulic excavator. It is determined from. Further, since the shape of the rear end face of the counterweight 6, that is, the outer surface 6b affects the turning radius of the upper swing body 2, the shape thereof has a predetermined radius centered on the swing center of the upper swing body 2. It has a circular arc or a shape close to a circular arc. Further, the height dimension is still a certain height dimension from the viewpoint of securing a rear view from the cab 4 and the like. In order to give a predetermined weight to the counterweight 6 in which the shape and height of the outer surface 6b are thus determined, the volume of the entire counterweight 6 is adjusted by appropriately setting the shape of the inner surface 6a side. Like that. Therefore, this counterweight 6
As for the shape of the inner surface 6a, for example, an intermediate portion thereof is a surface substantially in a direction orthogonal to the main frame 10, and portions on both left and right sides are generally configured to bend forward by a predetermined angle. It is.

On the other hand, the beam member 11 is provided in a direction orthogonal to the main frame 10, and the lower cover 14d is
Irrespective of welding or fastening with bolts, beam member 1
Fixed to 1. Inner surface 6a of counterweight 6
Although there is a part near the beam member 11, the beam member 1
Some parts are quite far from one. Therefore, the lower cover 1
4d, not the beam member 11 but this counterweight 6
Is extended toward the counterweight 6 so as to minimize the gap G according to the shape of the inner surface 6a. by the way,
The counterweight 6 moves while the vehicle is running or when the front working mechanism 3 is working. Since the counterweight 6 is supported at its substantially central portion by the two main frames 10, 10, it swings and vibrates up and down around this position, but also moves in the front-back direction. become. Therefore, the gap between the lower cover 14d and the inner surface 6a of the counterweight 6 is configured to be as small as possible within a range where the movement of the counterweight 6 is not hindered in consideration of the movement of the counterweight 6.

The inner surface 6a of the counterweight 6 has a structure shown in FIG.
As shown in FIG. 1, a sound absorbing material such as urethane foam and other packing materials 15 having elasticity are fixedly provided.
Is placed on the main frame 10, the lower cover 1
It comes in contact with 4d. If the packing material 15 is formed of a solid member such as rubber, the soundproofing efficiency is further improved.

Although the present invention is constructed as described above, noise is generated when the engine 12 is operated in order to operate the hydraulic excavator to run or to operate the front working mechanism. Since the engine 12 is surrounded by the machine room cover 14, leakage of this noise to the outside is minimized. However, the machine room cover 14
Of these, no cover is provided on the rear side, and there is a gap between the counterweight 6 and the gap, so noise leaks from this gap. However, the lower cover 14d is located very close to the counterweight 6. The gap between them is small, so that noise leaking downwards is minimized. In addition, since the gap is filled with the packing material 15, the noise reduction effect is further improved.

When the vehicle is running or work is performed by the front working mechanism, the counterweight 6 swings and vibrates.
4d, there is a gap G, and since this gap G is within a range in which the movement of the counterweight 6 is allowed, the counterweight 6 may come into contact with the lower cover 14d to generate noise. Also, there is no possibility that the lower cover 14d is deformed or damaged by the impact load. Since the counterweight 6 is supported by the two main frames 10, 10 at the intermediate position, the portion between the counterweights 6 hardly moves, but both ends move within a certain range. Therefore, the middle portion where the counterweight 6 is connected to the main frame 10 is narrow, and a relatively wide gap is formed at both end sides. The gap can be minimized in a state where there is no contact, and an extremely excellent noise reduction effect is achieved.

[0021]

Since the present invention has the above-described structure, it can be prevented.
The sound effect can be significantly improved and the vehicle
The lower cover may be damaged or deformed during operation.
This produces effects such as no inconvenience .

[Brief description of the drawings]

FIG. 1 is an external view of a hydraulic excavator as an example of a construction machine.

FIG. 2 is a plan view showing a rear part of an upper revolving structure of the hydraulic excavator provided with the soundproof structure according to the embodiment of the present invention, with a canopy cover removed.

FIG. 3 is a cross-sectional view of FIG.
It is X sectional drawing.

FIG. 4 is an enlarged view of a main part of FIG. 3;

[Explanation of symbols]

 2 Upper revolving structure 5 Machine room cover 6 Counter weight 10 Main frame 11 Beam member 12 Engine 13 Hydraulic pump 14 Machine room cover 14d Lower cover 15 Packing material

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F02B 77/13 F02B 77/11 E02F 9/00 E02F 9/18

Claims (4)

(57) [Claims] 1. An engine mounted on a body frame,
A counterweight is mounted at a position rearward of the engine mounting portion, and the engine is surrounded by a cover member. The lower cover of the cover member is turned toward the counterweight during the operation of the vehicle. It is provided to extend to a position separated by the range in which the counterweight moves, and the lower cover and the counterway
Packing made of elastic material in the gap formed between
An engine soundproofing device for a construction machine, wherein the engine soundproofing device is configured to be filled with a bearing member . 2. An engine mounted on a body frame,
Counterweight mounted behind the engine mounting part
And the engine is surrounded by a cover member.
The lower cover of the cover member
To the counterweight while the vehicle is running.
Extend to the position separated by the range where the unweight moves.
In the width direction of the counterweight.
Distance between the lower cover and the intermediate cover
Shorter than the separation distance at both ends of the weight
An engine sound insulation device for a construction machine, wherein 3. The vehicle body frame includes a plurality of main frames.
The counterweight has two main frames.
The lower cover and the counterweight.
It is these two that narrow the distance between
The book is characterized by being located between the mainframes of the book.
3. The engine soundproofing device for a construction machine according to claim 2 . 4. A packing comprising an elastic member in the gap.
3. The structure according to claim 2, wherein the member is filled.
Engine soundproofing equipment for construction equipment.