JP4486475B2 - Construction machinery noise reduction structure - Google Patents

Description

  The present invention relates to a noise reduction structure for a construction machine in which noise countermeasures are taken so that engine noise and hydraulic noise of the construction machine do not leak to the front of the machine body.

As an example of a construction machine, for example, in a hydraulic excavator 1, as shown in FIG. 5, a pair of left and right boom cylinders that raise and lower a boom 20 on a boom foot 3 serving as a base for pivotally attaching a boom at the front end of an upper swing body 1A. In order to pass the hydraulic hose 22 connected to 21, the distance plate 4 is provided with an opening 6.
On the other hand, behind the upper swing body 1A, as shown in FIG. 4, a heat exchanger 11 such as a radiator, a cooling fan 12, an engine 13, a hydraulic pump 14, and a muffler 15 are disposed inside the cover of the upper swing body 1A. Built in.
Therefore, there is a problem that engine sound and hydraulic sound released to the front of the aircraft by passing through the firewall W or the like in the cover leaks from the opening 6 and the noise level in front of the aircraft rises. .

Therefore, as a noise reduction structure of a hydraulic excavator, for example, in JP-A-11-254976, a heat exchanger such as a radiator and an oil cooler and an engine are cooled by an air flow generated by a fan, and the engine, the heat exchanger, and An exhaust part is provided on the upper surface of the cover that covers the fan to allow the air flow flowing out at an angle θ with respect to the axis of rotation of the fan to be discharged to the outside, and the exhaust resistance is reduced by reducing the exhaust resistance. A configuration for reducing noise is disclosed.
However, an effective reduction method has not been adopted for noise emitted forward through a firewall or the like.

On the other hand, as shown in FIG. 10, the distance plate 4 ′ is not provided with an opening, and the portion connected to the rear of the distance plate 4 ′, that is, the upper part of the section in which the hydraulic control valve 24 and the swivel unit are accommodated is made of sheet metal or the like. A covering configuration is known.
However, in this case, since no opening is formed in the distance plate 4 ', the destination of the hot air exhausted from the engine room disappears, and heat is trapped at the same time, and noise such as engine noise is also trapped. There was a problem that the level increased.

Furthermore, in order to reduce engine noise, a configuration is also known in which a rubber molded product cover is directly attached around the engine oil pan to reduce noise.
However, since this cover is manufactured in accordance with the shape of the engine oil pan, a mold is required, and the cover is expensive as a whole, and it takes time to manufacture.
JP, 11-254976, A Refer to Drawing 2, Drawing 6, and Drawing 9.

The present invention provides a noise reduction structure for a construction machine that can reduce the noise emitted to the front of the machine body. The first object is to provide a shielding plate that closes the opening of the distance plate at a separated position. The purpose is to limit noise.
The second problem is to make a hole through the upper swinging body to the lower traveling body to release noise and heat directly under the airframe to reduce noise.
A third problem is to reduce noise leaking from the engine oil pan by providing a cover that surrounds the periphery of the engine oil pan from below on the engine under cover.

In order to solve the first problem, the present invention provides a first aspect of the present invention.
Provided Bumufuto portion of the upper rotating body of the construction machine Ri cover and communicating of the upper frame covers the boom rearward, the noise reduction structure for a construction machine having a distance plate which is provided a base plate inclined downward toward the vehicle body front Because
The distance plate is provided with an opening for passing the hydraulic hose of the boom cylinder.
Inside the distance plate, a shielding plate having a surface that is large enough to close the opening as seen from the front side of the body is provided at a position separated from the opening.
A hydraulic control device is formed behind the shielding plate by forming a space through which the hydraulic hose of the boom cylinder can pass between the upper end of the shielding plate and the inclined inner wall surface of the base plate of the distance plate. The hydraulic hose is connected to
The interval between the shielding plate and the opening is set to an interval that does not restrain the movement of the hydraulic hose,
Characterized by comprising reducing the noise emitted to the fuselage forward by the said shielding plate.
In the invention of claim 2,
The space is formed between an upper end of the shielding plate and an inclined inner wall surface of the base plate of the distance plate .
In the invention of claim 3,
The shielding plate is made of a material having a high sound absorbing property, or a sound absorbing material is attached to the back surface of the shielding plate.

According to the first aspect of the present invention, by providing the shielding plate inside the opening of the distance plate, the noise emitted to the front of the aircraft can be reduced by the shielding plate.
Moreover, since the opening is formed as in the prior art, hot air from the engine room can be discharged from the opening.
In the invention of claim 2, since the shielding plate is separated from the opening, the operation of the hydraulic hose that moves following the boom cylinder interlocked with the boom undulation is not hindered.
Furthermore, the noise emitted forward over the shielding plate can collide with the inclined inner wall surface of the distance plate and be attenuated by reflection.

According to the third aspect of the present invention, by making a hole at a predetermined position of the bottom plate of the upper swing body, the hot air and noise released to the front of the body can be released from the hole toward the ground directly below the body.
In the invention of claim 4, the section in which the swivel unit is disposed is sealed, but exhaust of hot air and noise can be reduced by the hole.

In the invention of claim 5, since the engine oil pan is surrounded from the bottom by the cover provided on the engine under cover, the generation of noise can be reduced from the beginning.
In the invention of claim 6, since the cover is formed using the engine under cover, it can be manufactured inexpensively and easily.
In the invention of claim 7, since the cover is formed separately from the engine under cover, the cover can be replaced or changed, and the versatility is high.

  In this invention, the objective of reducing the noise which leaks from an opening part was implement | achieved by providing a shielding board in the position spaced apart from an opening part inside the opening part of the distance plate connected with the cover of an upper revolving body.

Hereinafter, an embodiment in which a noise reduction structure for a construction machine according to the present invention is applied to a hydraulic excavator will be described with reference to the drawings.
As shown in FIG. 1, the excavator 1 includes an upper swing body 1A and a crawler type suspension device 1B. The upper rear body of the upper swing body 1A is an engine room, and an engine cover that covers the outside of the engine room. 2 covers devices such as a heat exchanger such as a radiator 11, a cooling fan 12, an engine 13, a hydraulic pump 14, and a muffler 15 (see FIG. 4).

[Distance plate]
In addition, a distance plate 4 is fixed at the center of the boom foot portion 3 at the front center of the upper swing body 1A through the firewall W of the engine room.
As clearly shown in FIG. 3, the distance plate 4 has a bracket 4b for pivotally mounting the boom 20 above the pair of left and right side plates 4a, and below the boom 20 disposed as a pair on the left and right sides of the boom 20. Each has a bracket 4c pivotally attached to the cylinder 21, and has a base plate 4d that rises obliquely upward from a bottom plate 5a fixed to the base frame 5.

[Aperture]
A rectangular opening 6 through which the hydraulic hose 22 of the boom cylinder 21 passes is formed in the lower center of the distance plate 4.
This opening 6 is for passing the hydraulic hose 22 of the boom cylinder 21 pivotally attached to the bracket 4c below the distance plate 4 to the inside, and this hydraulic hose 22 is connected to the distance plate 4 in front of the firewall W. Are connected to a hydraulic control valve 24 disposed between the two.

[Shield]
A shielding plate 7 is erected on the bottom plate 5 a inside the distance plate 4 and at a position facing and separating from the opening 6.
In the present embodiment, the shielding plate 7 is disposed between the hydraulic control valve 24 and the opening 6.
The shielding plate 7 is set so as to have a surface with a size capable of closing the opening 6 when viewed from the front side of the machine body.
Further, the shielding plate 7 may be made of a material having a high sound absorbing property or a structure in which a known sound absorbing material is attached to the back surface of the shielding plate 7.

The interval between the shielding plate 7 and the opening 6 is preferably set to an interval that does not restrict the movement of the hydraulic hose 21.
In the illustrated example, a space S is formed between the upper end of the shielding plate 7 and the inclined inner wall surface of the base plate 4 d of the distance plate 4.

Because of the above configuration, noises (indicated by arrows in FIG. 2) such as engine sound and hydraulic sound emitted from the engine room side to the front of the aircraft are absorbed by the shielding plate 7 or reflected and attenuated. Is done.
Further, the noise over the shielding plate 7 can collide with the inner wall surface of the base plate 4d of the distance plate 4 and be reflected and attenuated.
In this case, a sound absorbing material may be attached to the inner wall surface of the base plate 4d.
As a result, even if engine sound, hydraulic sound, or the like is released to the front of the aircraft, the noise leaking from the opening 6 by the shielding plate 7 is attenuated, and the noise level in front of the aircraft is not increased.

In the present embodiment, a flat plate is exemplified as the shielding plate 7, but a folded plate structure, a curved shape, and other appropriate shapes may be used.
Moreover, the shielding board 7 should just have the surface which plugs up an opening part when the opening part 6 is seen from the front, and may be formed in the upper and lower sides or the left and right more than that. .

Next, FIG. 6 shows a noise reduction structure in which noise such as engine sound emitted from the engine room to the front of the aircraft is not diffused to the surroundings.
In the conventional example of FIG. 10, the opening 6 is not provided in the distance plate 4 ′, and the hydraulic control valve is not disposed in the internal space partitioned by the distance plate 4 ′. For example, the side of the boom facing the cab is used. (Not shown).
The portion connected to the upper end of the distance plate 4 ′, that is, the upper part of the section A where the turning unit is arranged is covered with a sheet metal 8 or the like and sealed.
The present embodiment is characterized in that a hole portion 9 that penetrates downward is provided in a predetermined bottom wall surface provided with a turning unit in the upper turning body 1A.

[Swivel unit]
As shown in FIGS. 6 and 7, the swivel unit has an annular bearing 31 fixed to the bottom surface of the upper swivel body 1A, and is rotatably supported by the bearing 31 via a steel ball. A connected outer ring 32, a gear 32a formed on the inner circumference of the outer ring 32, an inner ring 33 having a gear 33a meshing with the gear 32a on the outer circumference, and an upper turning provided on the rotation shaft of the inner ring 33 The swing motor 34 is fixed in the body 1A, and a swivel joint 35 is provided at the center position and sends pressure oil to various hydraulic motors.

[Hole]
This swivel unit is disposed inside the distance plate 4 ′, and as described above, is covered and sealed with the sheet metal 8 or the like.
A swing motor 34 and a swivel joint 35 are erected on the bottom plate 5 a of the section A between the distance plate 4 ′ and the firewall W.

  Therefore, in the virtual area indicated by the phantom line in FIG. 7 and hatched inside, that is, in the hole forming area R around the swivel joint 35 and avoiding the position corresponding to the outer ring 32 and the position corresponding to the inner ring 33, the bottom plate A through hole is drilled in 5a.

  For example, as shown in FIG. 8, a plurality of (three in the illustrated example) hole portions 9 are formed in the partition area A around the swivel joint 35, so that it is discharged into the partition A. Noises such as hot air and engine noise can be released to the space directly below the aircraft through the hole 9 (see FIG. 6).

  In this way, by releasing the hot air toward the lower part of the aircraft, the engine sound and the like emitted together with the hot air can be released to the ground below the aircraft, so that the diffusion of the noise such as the engine sound around the aircraft can be reduced.

  FIG. 9 shows a case where the noise reduction structure of the first embodiment is combined, and an opening 6 is provided in the distance plate 4, and a portion connected to the upper end of the distance plate 4, that is, a section in which the turning unit is arranged. The upper part of A is covered with a sheet metal 8 or the like.

The shielding plate 7 of the first embodiment is provided at a position facing the opening 6 and spaced apart.
In this case, a hydraulic control valve 24 is provided in the section A. If the hole 9 is provided at a position excluding the hydraulic control valve 24, hot air and noise are also released from the hole 9. be able to.

Next, in the engine room, the engine sound emitted to the airframe can be reduced by providing the cover 10 surrounding the engine oil pan 16.
In this embodiment, the cover 10 is formed in a pedestal shape with a thin sheet metal without using a mold.

[Cover]
The cover 10 shown in FIGS. 11 and 12 has a box shape with an upper surface and one side open, and is integrally formed with an engine under cover 17 that is detachably attached to the engine cover 2 below the engine 13.
Since the cover 10 is opened not only on the upper surface but also on one side surface, it can be stored even if the size of the engine oil pan 16 is different, and is highly versatile.

The cover 10 has a substantially U-shaped support peripheral wall 17a as seen from a plan view by cutting a part of the engine under cover 17 in three directions.
The support bottom wall 17b is horizontally fitted at a midway position in the height direction between the support peripheral walls 17a, and the edges are fixed, and the upper part from the support bottom wall 17b is covered 10.
Here, it is preferable to attach a sound absorbing material (not shown) to the upper surface of the support bottom wall 17b and the inner wall surface of the support peripheral wall 17a rising above the support bottom wall 17b.

Since it consists of the said structure, the cover 10 covers the engine oil pan 16 by attaching the engine under cover 17 to the bottom face of the engine cover 2, and functions as a noise reduction box.
When the engine under cover 17 is removed, the cover 10 is also detached from the engine oil pan 16 at the same time.

A cover 10 shown in FIG. 13 includes a sheet metal box 10A having an upper surface and one side open, and a sound absorbing material block 10B such as glass wool is attached to each inner wall surface.
In the present embodiment, a hook-like connection convex portion (not shown) is provided on the inner wall surface of the cover 10, and the sound receiving block 10B is provided with a connection receiving portion 31 that engages with the connection convex portion. The sound absorbing block 10B can be easily attached to the inner wall surface.

On the other hand, the engine under cover 17 is cut and raised left and right or in three directions to form a support peripheral wall 17a '.
Then, a mounting piece 32 extending downward is fixed to the side wall of the cover 10, and the distal end of the extending piece 32 is fixed to the left and right support peripheral walls 17a 'with screws 33, so as to be detachable. To do.
This detachably fixed configuration is not limited to the configuration of the above-described embodiment, and a known engagement means or latching means may be used.

In this way, the cover 10 is supported on the engine under cover 17.
In this case as well, the cover 10 can be surrounded by the attachment / detachment of the engine under cover 17 so as to cover the engine oil pan 16 (see FIG. 12).
In the above embodiment, a case where the cover 10 is formed by cutting and raising a part of the engine undercover 17 or a wall surface supporting the cover 10 is illustrated. However, a support piece separate from the engine undercover 17 is used as the engine. The cover 10 may be supported by standing on the under cover 17.

In addition, each of the above embodiments may be applied individually or may be applied in combination with different embodiments.
In addition, it goes without saying that various design changes can be made without departing from the scope of the present invention.

It is the front view which omitted front attachments, such as a boom, in order to show the opening part of the distance plate of a hydraulic excavator. It is explanatory drawing of Example 1 seen from the side surface which shows attenuation | damping of the noise discharge | released ahead of a body. It is a perspective view of a distance plate. It is explanatory drawing which shows the structure of the engine room of an aircraft back body from the back side roughly. It is explanatory drawing seen from the side surface which shows the leak of the noise discharge | released ahead of the conventional body. It is explanatory drawing of Example 2 seen from the side surface which shows attenuation | damping of the hot air and noise which are discharge | released ahead of a body. It is a top view which shows a turning unit and a hole part formation area. It is a top view which shows a hole part. It is explanatory drawing seen from the side surface at the time of combining the structure of Example 2 with Example 1. FIG. It is explanatory drawing seen from the side surface which shows the flow of the hot air of the conventional structure which covered the upper end of the distance plate with the sheet metal, and was continued with the engine cover, and the noise. 10 is a perspective view showing a cover of Example 3. FIG. It is a side view of FIG. It is a perspective view which shows the cover of Example 4. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hydraulic excavator 1A Upper revolving body 1B Lower traveling body 2 Engine cover 3 Boom foot part 4 Distance plate 5 Base frame 6 Opening part 7 Shielding plate 8 Sheet metal 9 Hole part 10 Cover 11 Radiator 12 Cooling fan 13 Engine 14 Hydraulic pump 15 Muffler 16 Engine oil pan 17 Engine under cover 20 Boom 21 Boom cylinder 22 Hydraulic hose 24 Hydraulic control device

Claims (2)

A construction machine noise reduction structure that has a distance plate that is provided at the boom foot of the upper swing body of the construction machine, covers the rear of the boom, is connected to the cover of the upper swing body, and has a base plate that is inclined downward toward the front of the machine body. And
The distance plate is provided with an opening for passing the hydraulic hose of the boom cylinder.
Inside the distance plate, a shielding plate having a surface that is large enough to close the opening as seen from the front side of the body is provided at a position separated from the opening.
A hydraulic control device is formed behind the shielding plate by forming a space through which the hydraulic hose of the boom cylinder can pass between the upper end of the shielding plate and the inclined inner wall surface of the base plate of the distance plate. The hydraulic hose is connected to
The interval between the shielding plate and the opening is set to an interval that does not restrain the movement of the hydraulic hose,
Noise reduction structure for a construction machine characterized by comprising reducing the noise emitted to the fuselage forward by the shielding plate. The noise reduction structure for a construction machine according to claim 1, wherein the shielding plate is made of a material having a high sound absorbing property, or a sound absorbing material is attached to the back surface of the shielding plate.

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