JP2622285B2 - Construction vehicle soundproof structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial application field The present invention prevents noise generated by an engine mounted as a prime mover of a construction vehicle such as a backhoe, and is a source of construction noise in night work and the like. It reduces the noise of existing construction vehicles.

(B) Prior Art Conventionally, as a soundproof structure of a construction vehicle, a technique in which the surroundings of an engine and a radiator are covered with a soundproof shielding cover is known.

For example, as disclosed in Japanese Utility Model Laid-Open No. 55-121726.

(C) Problems to be Solved by the Invention However, in the conventional technology, the surroundings of the engine and the radiator are covered and sealed with a soundproof shielding cover, but a cooling air suction port for sucking the cooling air of the engine. And, since the exhaust air outlet after cooling from the radiator is greatly opened on the left and right surfaces of the soundproof shielding cover,
Despite being sealed by the soundproof cover, noise of the engine and the radiator leaked out from the cooling air opening and the exhaust air opening, and a large soundproofing effect could not be obtained.

FIG. 11 shows a soundproofing effect when the soundproofing cover is covered around a noise source such as an engine and sealed.

As can be determined in the drawing, the hole opening ratio of the soundproof shielding cover, Then, the aperture ratio has a large effect on the soundproofing effect,
As the aperture ratio approaches 0, the level decreases and the soundproofing effect increases.

However, since the engine takes in air and burns with fuel, an opening for taking in the air and a radiator for dissipating and cooling the heat generated by the combustion of the engine are required. The intake port and the exhaust air outlet for exhausting the exhaust air after cooling must be opened.

Even when these openings are minimized and the minimum opening ratio c in FIG. 11 is obtained, the noise level is reduced only to a.

In the present invention, a duct or other soundproof shielding cover provided in the opening is provided so as to further increase the soundproofing effect and achieve a lower noise level d than the noise level a based on the required minimum opening rate. The shape is taken into consideration.

(D) Means for Solving the Problems The object of the present invention is as described above, and a configuration for achieving the object will be described below.

In claim (1), the soundproof shielding room A of the construction vehicle is divided by a partition wall G into an engine room A1 for storing the engine E and a radiator room A2 for disposing the radiator 2, and the radiator on the side of the radiator room A2 is defined. 2, a cooling exhaust outlet F is provided at the position facing the engine room 2, only a cooling air inlet is provided on the engine room A1 side, and the radiator fan 3 is connected to the engine room via a communication port provided in a partition wall G for partitioning the two rooms. The air in A1 is configured to be sucked, and the communication port is disposed on the partition wall G at a position apart from a linear position connecting the cooling exhaust discharge port F and the engine E.

In claim (2), the radiator air passage M of the cooling air discharged from the radiator fan 3 in the radiator chamber A2 according to claim (1) is formed along the partition wall G.
An upper communication duct N is attached to the engine, and the upper communication duct N allows the discharge amount of the radiator fan 3 to be blown from the radiator chamber A2 to the engine room A1.

(E) Embodiment The purpose and configuration of the present invention are as described above. Next, the configuration of the embodiment shown in the attached drawings will be described.

1 is a side view of a backhoe of a construction vehicle, FIG. 2 is a plan view of the same, and FIG. 3 is a perspective view of a frame case B of the backhoe.

At the rear of the crawler-type traveling device 30, an earth discharging plate 27 that can discharge earth and sand is disposed.

In addition, the backhoe has a swing table bearing device provided on the crawler type traveling device 30, and the frame case B is pivotally supported on the swing table bearing device so as to be rotatable 360 degrees.

A boom 28 is pivotally supported at the front of the frame case B, and a bucket 29 is supported at the tip of a bucket boom above the boom 28.

A driver seat S and a steering column H are arranged on the left side of the frame case B in front and rear, and a hydraulic oil tank 31 for a hydraulic device is arranged on the upper surface of the frame case B on the right side.

The rear half of the frame case B is provided with a soundproof cover C which is a main part of the present invention.
Is divided into an engine room A1 and a radiator room A2.

Further, as disclosed in FIG. 3, the frame case B is surrounded by a wide side plate, the lower surface is formed in a box shape closed by a bottom plate 13, and the inside is formed by a cooling air suction duct m. It is.

A bumper / weight 1 is disposed around the joint between the soundproof shielding cover C and the frame case B.

A cooling air opening 33 is provided at the front end of the frame case B on the side of the base of the boom 28. The cooling air opening 33
The cooling air sucked from above passes through the suction duct m and enters the radiator chamber A2 through the opening 34 provided at the front of the radiator chamber A2.

In this way, in the radiator chamber A2, the cooling air opening 33 of the radiator 2 which is absolutely necessary is formed by the long suction duct m.
Through the opening at the front end of the frame case B to disperse the discharge port of the noise generated by the engine E,
The same soundproofing effect as when the noise sources are dispersed can be exhibited, and the noise level can be reduced.

The suction duct m is formed inside the frame case B, but is on the side opposite to the driver seat S and the steering column H side. There is no problem that the noise of the engine E and the fan leaks and propagates through the gap of B.

Further, since the cooling air opening 33 is located at a position distant from the engine E and also away from the exhaust air discharge port F, the engine E
Is separated into front and rear, so that the overall noise level can be reduced.

Further, since the cooling air opening 33 and the exhaust air discharge port F described later are also opened at a position away from the driver's seat S, the noise at the position at the ear of the operator during driving can be reduced. is there.

The radiator cooling air is also sucked in from the cooling air opening 33, but other parts that absorb the cooling air for cooling the inside of the engine room A1 are formed in the duct / frames 10, 11 below the engine room A1. It is being done.

FIG. 4 is a plan view of the engine room A1 and the radiator room A2, FIG. 5 is a rear sectional view of the same, FIG. 6 is a right side sectional view, FIG. 7 is a left side sectional view, and FIG. 9, FIG. 9 is a rear view of the same, FIG. 10 is a drawing showing the relationship between the cooling water temperature and the rotation speed of the radiator fan 3, and FIG.
FIG. 11 is a diagram showing the relationship between the hole opening ratio and the noise level, FIG. 12 is a hydraulic circuit diagram showing a configuration in which the number of revolutions of the radiator fan 3 is changed to two stages, and FIG. 13 is a diagram in which the radiator fan 3 has an axial flow. It is a drawing of a structure.

The details of the present invention will be described with reference to FIGS. 4, 5, 6, and 7.

As described above, the frame case B has the bottom plate 13 adhered to the lower surface, the upper surface is formed in a box shape closed by a hydraulic oil tank 81 and steps, and the rear upper surface of the frame case B is covered with the soundproof cover C. The rear part of the frame case B and the soundproof cover C constitute the soundproof room A.

As shown in FIG. 5, the soundproof shield room A is divided into an engine room A1 at the rear of the driver's seat S and a radiator room A2 at the rear of the hydraulic oil tank 31 to improve the soundproof effect. It is.

Inside the engine room A1, a fuel tank 7, an air filter 5, and an exhaust muffler 6, which are integrally formed with the soundproof cover C, are arranged above the engine E.

A cooling water pump 4 is provided at a position attached to the engine E.
The cooling water pump 4 is provided with a pulley 16 provided on an engine crankshaft 17 as shown in FIG.
It is driven by a belt wound between a generator pulley 18 and a cooling water pump pulley 15.

Therefore, since the rotation speed of the cooling water pump 4 is based on the rotation speed of the engine crankshaft 17 of the engine E, the rotation speed cannot be changed for control.

Conventionally, the axis of the cooling water pump 4 and the rotation axis of the radiator fan 3 are set to be the same, and the rotation speeds of both are set to be the same. However, in the present invention, the rotation of the cooling water pump 4 is changed. Although the number of belts is driven by an engine crankshaft 17 as in the prior art, the radiator fan 3 is driven by a hydraulic motor 9, and the hydraulic motor 9 is driven by supplying hydraulic oil from a hydraulic pump 21 attached to the engine E. It is composed.

Therefore, the amount of oil discharged from the hydraulic pump 21 is
The rotation speed of the hydraulic motor 9 can be changed by changing the rotation speed of the hydraulic motor 9 by the water temperature sensor provided at the cooling water outlet of the radiator 2.
The feed is made possible by 40 and the gear can be shifted to two stages.

Also, the exhaust from the exhaust muffler 6 is connected to the connecting duct 14,
Finally, the air is discharged to the lower side of the fuselage through the silencer 8, thereby dispersing the noise.

The flywheel case 20 is located on the left side of the engine E.
The flywheel case 20 is provided with a hydraulic pump 21. The hydraulic pump 21 is provided with a hydraulic motor 9 for driving the radiator fan 3 as described above.
In addition to the pump that discharges pressure oil to the
Also, a pump that discharges pressure oil to a hydraulic cylinder disposed in the portion of the boom 28 is provided.

In this configuration, when the surface temperature of the exhaust muffler 6 and the engine E rises because the engine room A1 has a closed structure, it is necessary to cool the inside.

In the present invention, the fan case 12 of the radiator fan 3 communicates with the engine room A1 at the communication port 43, and the engine room A1
In the lower part of the frame, a duct combined frame 1 with the engine E mounted
The air for indoor cooling is sucked from the intake duct provided in the portions 0 and 11.

That is, as shown in FIG. 7, the duct-cum-frames 10, 11 open the lower surface openings 10a, 11a, and inhale air from the portions, pass through the ducts formed by the duct-cum-frames 10, 11, and vice versa. It is guided to the inside of the engine room A1 from the side openings 10b and 11b provided at the ends.

Therefore, since the lower surface openings 10a and 11a and the side openings 10b and 11b do not overlap, the noise in the engine room A1 cannot directly go outside, and although the opening is open, the portion of the duct is open. Can improve the soundproofing effect.

On the duct / combined frames 10, 11, anti-vibration rubber 22, 23L,
The engine E is supported via 23R.

The cooling air in the engine room A1 is sucked from the lower openings 10a and 11a, and after the air cools the lower part in the engine room A1, the cooling air is sucked into the fan case 12 from the communication port 43 described above, Discharged in the centrifugal direction by the radiator fan 3,
It is discharged into the radiator air passage M.

Part of the cooling air sent from the radiator fan 3 to the radiator air passage M can be sent again to the upper part of the engine room A1 via the upper communication duct N.

The cooling air from the lower openings 10a and 11a
Therefore, cooling air is sent from the upper communication duct N into the engine room A1 as cooling air for cooling the upper portion of the engine room A1.

The upper communication duct N also has an opening 44 on the radiator chamber A2 side.
And the maze duct so as not to overlap with the opening 45 on the engine room A1 side, so that the noise inside the engine room A1 does not leak from the non-wind discharge port F via the upper communication duct N. ing.

The cooling water discharged from the cooling water pump 4 is supplied from the thermostat valve 47 through the cooling water pipe 46 to the radiator 2.
After cooling, the cooling water passes through the portion of the water temperature sensor 40 and returns to the cooling water pump 4 again through the cooling water pipe 48.

Next, the configuration of the radiator chamber A2 will be described.

A partition G is provided between the engine room A1 and the radiator room A2.
Is divided and quarantined. The above-described upper communication duct N is attached to the open wall G.

Since the conventional radiator fan 3 is driven by the same axis as the axis of the cooling water pump 4, the radiator fan 3
The fan itself moves up and down with the vibration of the engine E,
A large gap had to be made so as not to make contact with the 12.

In the present invention, since the radiator fan 3 is driven by the hydraulic motor 9, there is no need to directly connect the engine E, and the radiator fan 3 is supported by the frame case B, and a minimum gap is provided between the radiator fan 3 and the fan case 12. It is.

Therefore, it is not necessary to use an axial fan as in the related art, and a centrifugal fan such as a sirocco fan can be used as in the embodiment.

The centrifugal flow fan can obtain a static pressure discharge air at a low rotation speed as compared with the axial flow fan, and greatly contributes to reduction of noise.

In addition, due to the high static pressure, it is possible to send a sufficient amount of air even if the front suction port 3a and the rear suction port 3b are arranged at the back of the duct. Can be reduced.

The side opposite to the driver seat S of the frame case B is formed as a suction duct m having a cooling air opening 33 opened.

The opening 34 at the rear of the suction duct m communicates with the radiator chamber A2.

Therefore, the cooling air passes through the cooling air opening 33, the suction duct m, and the opening 34, and as shown in FIG.
The air taken in from the air is discharged in the centrifugal direction by the radiator fan 3, the direction is controlled by the air flow direction plates 24, 25, 26, passes through the radiator 2, and becomes the radiator cooling air discharged from the exhaust air discharge port F.

As described above, the communication port 43 is formed between the engine room A1 and the communication port 43, and the cooling air of the lower openings 10a and 11a is sucked from the communication port 43, and the radiator fan 3 moves the cooling air to the upper radiator air passage M. It is discharging.

The radiator fan 3 is constituted by a sirocco fan, and is driven by a fan shaft 3c. The fan shaft
3c is driven by the hydraulic motor 9.

As shown in FIGS. 8 and 9, the radiator fan 3 is a sirocco fan having a front opening with a front suction port 3a and a rear opening with a rear suction port 3b. The cooling air is sent to both of the chambers A2.

Next, in FIG. 10, the relationship between the water temperature sensor 40, the thermostat valve 47, and the shift of the hydraulic motor 9 will be described.

If the cooling by the radiator 2 is performed while the temperature of the cooling water does not sufficiently rise at the initial stage of the start of the engine E, the temperature of the engine E does not rise forever and the incomplete combustion occurs. When the water temperature is low, the circulation amount of the cooling water is reduced to promote the temperature rise.

That is, in FIG. 10, curves A, B, C, and D indicate the radiator inlet temperatures, and curves I, II, III, and IV illustrate the radiator outlet temperatures.

When the thermostat valve 47 is not fully throttled and the throttle operation is not performed, the radiator inlet temperature follows curves d to a. Similarly, the radiator outlet temperature follows curves III-I.

In this case, the interval between the two curves indicating the temperature difference between the inlet and the outlet of the radiator is narrow, the cooling effect of the radiator is low, and the temperature of the engine does not rise forever in the early stage of engine start, so incomplete combustion occurs. It is.

Next, when the load on the engine E is low and the amount of cooling water is reduced by the thermostat valve 47, the radiator inlet temperature follows the curves H to Y, and the radiator outlet temperature changes according to the curves.
It follows IV-I.

In this manner, by narrowing down the thermostat valve 47 at a low load, the temperature of the cooling water of the engine E can be increased at a low load.

In the present invention, in addition to this, the coolant temperature is detected by a coolant temperature sensor 40, and the hydraulic motor 9 is shifted in two steps.
A hysteresis portion is generated halfway along b. The radiator outlet temperature follows the curves II to I, and also in this case, a hysteresis portion occurs on the way.

By changing the rotational speed of the radiator fan 3 in this manner, the inlet temperature can be increased at a low load, and the outlet temperature is also increased at a low load, but this has no adverse effect.

Furthermore, since the noise level of the radiator fan 3 can be reduced by lowering the rotation speed of the radiator fan 3 at the time of a low load, this effect is greater.

 Next, FIG. 13 will be described.

FIG. 13 is a drawing in which the radiator fan 3 is constituted by an axial fan.

The point that the fan drive shaft 3c of the radiator fan 3 constituted by the axial fan is driven by the hydraulic motor 9 is the same, but since the fan drive shaft 3c is arranged in parallel with the engine crankshaft 17, the hydraulic motor It is also possible to drive by winding a V-belt between the two instead of driving by the drive unit 9.

A partition G is provided between the engine room A1 and the radiator room A2.
Is the same as that of the engine compartment A1.
The cooling air inside is configured to pass through the inside sucked by the suction force of the radiator fan 3.

That is, duct / combination frames 10 and 11 are provided in the bottom plate 13 at the lower part of the frame case B, and the duct / combination frames 10 and 11 have lower surface openings 10a and 11a and side openings 10b and 11b.
Is provided, and the lower part of the engine E is cooled by the cooling air.

In addition, a cooling air inlet 53 for the engine room A1 is provided, and the cooling air sucked in from the cooling air inlet 53 passes through the communication hole 51, passes through the radiator chamber A2, and is then cooled. It is discharged from F.

(F) Effects of the Invention Since the present invention is configured as described above, the following effects can be obtained.

Since the engine E is configured as described in claim 1, the noise of the engine E does not linearly reach the cooling exhaust discharge port F through the communication port of the partition wall G, and the communication port which is a detour is always provided. Since the cooling air is discharged to the cooling air discharge port F, the noise of the engine E emitted from the cooling air discharge port F can be reduced by the bypass communication port.

In addition, only the cooling air intake is provided on the side of the engine room A1, and the cooling air intake is formed in a maze shape and is formed as a long duct, so that the engine noise level can be reduced. is there.

In addition, the cooling air discharge port F from the radiator 2 needs to open directly to the outside air, but since the partition wall G is disposed between the cooling air discharge port F and the engine E cooling air discharge port F. In addition, the noise of the engine E does not leak to the outside from the cooling exhaust air discharge port F directly.

Further, the cooling air in the engine room A is sucked through the communication port by the radiator fan 3 to create a flow of the cooling air, so that the surfaces of the engine E and the exhaust muffler can be sufficiently cooled.

The radiator air passage M of the cooling air discharged from the radiator fan 3 in the radiator chamber A2 is formed along the partition G, and the upper communication duct N is attached to the partition G, as in claim (2). Since the discharge air from the radiator fan 3 can be blown from the room A2 to the engine room A1, the discharge air from the radiator fan 3 is used as cooling air even though the engine room A1 and the radiator room A2 are partitioned by the partition G. It becomes possible to send the cooling air into the chamber A1, and after cooling, the air is sucked into the radiator fan 3 again from the lower communication port 43, so that a cooling air circulation path can be formed.

[Brief description of the drawings]

1 is a side view of a backhoe of a construction vehicle, FIG. 2 is a plan view of the same, and FIG. 3 is a frame case B of the backhoe.
FIG. 4 is a plan view of the engine room A1 and the radiator chamber A2, FIG. 5 is a rear cross-sectional view, FIG. 6 is a right side cross-sectional view, FIG. 7 is a left side cross-sectional view, and FIG. 9 is a side view of the radiator fan 3, FIG. 9 is a rear view thereof, FIG. 10 is a diagram showing a relationship between the cooling water temperature and the rotation speed of the radiator fan 3, and FIG. 11 is a diagram showing a relationship between the aperture ratio and the noise level. Show drawing, No.
FIG. 12 is a hydraulic circuit diagram showing a configuration in which the number of rotations of the radiator fan 3 is changed to two stages, and FIG. A: Soundproof isolation room A1: Engine room A2: Radiator room B: Frame case C: Valve with throttle E: Engine F: Exhaust air discharge port M: Radiator air passage N: Upper communication duct m Suction duct 1 Bumper combined weight 2 Radiator 3 Radiator fan 4 Cooling water pump

Claims (2)

(57) [Claims] 1. A soundproof shielding room A of a construction vehicle is divided by a partition wall G into an engine room A1 for storing an engine E and a radiator room A2 for arranging a radiator, and a surface of the radiator 2 on the side of the radiator room A2. A cooling air discharge port F is provided at the position where the cooling air is discharged, only a cooling air suction port is provided on the engine room A1 side, and the radiator fan 3 is connected to the inside of the engine room A1 by a radiator fan 3 through a communication port provided in a partition wall G for partitioning both chambers. A soundproof structure for a construction vehicle, wherein the structure is configured to suck air, and the communication port is disposed on a partition wall G at a position away from a linear position connecting the cooling exhaust discharge port F and the engine E. 2. A radiator air passage M for cooling air discharged from a radiator fan 3 in a radiator chamber A2 according to claim 1 is formed along a partition G, and an upper communication duct N is attached to the partition G. A soundproof structure for a construction vehicle, characterized in that the upper communication duct N allows the air discharged from the radiator fan 3 to be sent from the radiator chamber A2 to the engine room A1.