JPH05139219A - Noise suppressing device in industrial vehicle - Google Patents

Abstract

PURPOSE:To improve cooling efficiency of a radiator by efficiently decreasing noise such as engine operating noise generated rearward from a radiator, and preventing cooling air from acting as a reverse flow. CONSTITUTION:This noise suppressing device is provided with a cylindrical noise absorption member 18 arranged coaxially with the center line of a fan 13 just behind a radiator 12 in the cooling air passage 15 of a counter weight 11 installed on the rear of a vehicle body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial vehicle such as an engine type forklift, and more particularly to a device for reducing noise emitted rearward from a radiator.

[0002]

2. Description of the Related Art In a large-sized engine type forklift, as shown in FIGS. 5 and 6, a counterweight 1 installed at a rear portion of a vehicle body is obliquely cut out to form a cooling air passage 2 and an upper portion thereof. Is used as the cooling air outlet 3. In such a configuration, the cooling air blown backward from the radiator 4 contacts the inclined surface 5 of the counterweight 1 and then changes its direction upward, so that the upper cooling air discharge port 3
Discharged from. At the same time, the radiator 4 also emits noise such as an operating noise of the engine 6, a wind noise of the fan 7, and a wind noise of the radiator 4. These sounds are the largest noise sources to the driver's ears and surroundings.

In order to reduce such noise, in general, a plurality of sound absorbing plates 8 are generally arranged in the cooling air passage 2 of the counterweight 1 in parallel to the direction of the cooling air and laterally spaced from each other. The sound absorbing plate 8 absorbs noise by placing it upright.

[0004]

However, when such a sound absorbing plate 8 is installed, the cross section of air passage is reduced,
There is a problem that the cooling air volume decreases and the cooling efficiency of the radiator 4 decreases.

On the other hand, in a large forklift,
A large fan 7 is also used, but the blades 7a of the fan 7 are considerably shorter than the diameter of the hub 7b due to the problem of strength. Therefore, as shown in FIG. 7, there is almost no wind in the part on the fan center line immediately after the radiator,
If the air resistance behind the radiator 4 is increased by directing the cooling air exhaust port 3 upward, the cooling air is rewound (backflow) to the no-air state portion, and the cooling efficiency of the radiator 4 is reduced. There is a fear.

Therefore, it is an object of the present invention to effectively reduce noise such as engine operating noise emitted rearward from a radiator, and to prevent backflow of cooling air to improve cooling efficiency of the radiator. To provide a device.

[0007]

In order to achieve the above object, a noise reducing device according to the present invention is provided in a cooling wind passage of a counterweight mounted on a rear portion of a vehicle body, immediately after a radiator and immediately after a fan center line. It is characterized in that a cylindrical sound absorbing member is arranged coaxially with.

[0008]

In the above structure, part of the noise that has passed through the radiator is absorbed by the sound absorbing member. Further, since the sound absorbing member is arranged in the airless state portion in the cooling air passage, it serves as a barrier for preventing backflow of the cooling air without reducing the air volume of the cooling air.

[0009]

1 and 2 show a preferred embodiment of the present invention. As shown in the figure, a large-sized engine-type forklift to which the present invention is applied has an engine 10 arranged inside the vehicle body, a counterweight 11 arranged at the rear portion of the vehicle body, and an engine, as in the conventional configuration described above. 1
And a radiator 12 arranged between the counter weight 0 and the counter weight 11. Further, a fan 13 driven by the engine 10 is provided between the engine 10 and the radiator 12, and the cooling air generated by the fan 13 cools the cooling water in the radiator 12. The noise to be reduced by the present invention includes the operating noise of the engine 10, the wind noise caused by the fan 13, the wind noise generated when the cooling air passes through the radiator, and the like. The cooling air that has passed through the radiator is discharged upward from the cooling air intake 14 at the front part of the counterweight 11 through the cooling air passage 15 and from the upper cooling air exhaust port 16. The bottom surface of the cooling air passage 15 is an inclined surface 17 that faces upward when viewed from the radiator 12 side, and the cooling air blown backward from the radiator 12 changes its direction upward by this inclined surface 17 and the cooling air exhaust is performed. It is discharged from the outlet 16.

According to the present invention, the cylindrical sound absorbing member 18 is arranged immediately after the radiator in the cooling air passage 15 of the counterweight 11. The sound absorbing member 18 is
For example, it is attached so as to be coaxial with the center line of the fan 13 by means of a thin support plate 19 or the like that is horizontally installed in the cooling air passage 15. Further, the dimensions of the sound absorbing member 18, that is, the outer diameter and the axial length thereof, are set so as to be able to occupy a portion immediately after the radiator 12 which would otherwise be in a substantially windless state. Although various configurations of the sound absorbing member 18 are possible, as shown in FIG. 3, a sound absorbing member 21 such as urethane foam attached to the outer peripheral surface of a cylindrical body 20 such as a steel pipe or a round bar, or
As shown in FIG. 4, a cylindrical body 2 made of punching metal
It is preferable that the inside of 2 is filled with a sound absorbing material 23 such as glass wool or urethane foam (open cell).

In such a structure, the radiator 12
A part of the noise such as the engine operating sound that has passed through is absorbed by the sound absorbing member 18 and is reduced. Further, since the sound absorbing member 18 is arranged in the windless portion,
The cooling air generated by the fan 13 is the radiator 12
After passing through, the sound absorbing member 18 flows around the sound absorbing member 18, and the sound absorbing member 18 does not hinder the flow of the cooling air. Further, in the case of the structure in which the cooling air discharge port 16 of the counterweight 11 is directed upward and the air resistance increases as in this embodiment, the cooling air flows along the fan center line in the radiator 1.
Although it tries to backflow to the 2 side, it is surely guided to the upper cooling air discharge port 16 without backflow due to the presence of the sound absorbing member 18.

As shown in FIGS. 1 and 2, when the sound absorbing material 24 is attached to the inclined surface 17 of the counterweight 11, noise which is not absorbed by the sound absorbing member 18 can be absorbed.
The noise reduction effect is further enhanced. Further, although the present invention is applied to a forklift in the above-mentioned embodiments, it goes without saying that the present invention can also be applied to other industrial vehicles.

[0013]

As described above, according to the present invention, since the noise emitted rearward from the radiator is absorbed by the cylindrical sound absorbing member, the driving / working environment is improved.

Further, since the absorbing member is arranged on the flow path of the backflow of the cooling air, it has a function of preventing the backflow of the cooling air and smoothing the flow thereof. Moreover, since that position is a portion in the cooling air passage which is originally in a no-air state, the cooling air amount is not reduced. Therefore, by installing this sound absorbing member, it is possible to improve the cooling efficiency of the radiator.

[Brief description of drawings]

FIG. 1 is a sectional view schematically showing an embodiment of a noise reduction device according to the present invention.

FIG. 2 is a plan view of the noise reduction device shown in FIG.

FIG. 3 is a perspective view showing a configuration of a sound absorbing member used in the noise reduction device of the present invention.

FIG. 4 is a perspective view showing another configuration of the sound absorbing member used in the noise reduction device of the present invention.

FIG. 5 is a sectional view schematically showing a conventional noise reduction device.

FIG. 6 is a plan view of the conventional noise reduction device shown in FIG.

FIG. 7 is a cross-sectional view showing a state of the flow of cooling air in the cooling air passage of the counterweight.

[Explanation of symbols]

 10 engine 11 counterweight 12 radiator 13 fan 15 cooling air passage 18 sound absorbing member

Claims (1)

[Claims] 1. An engine disposed inside a vehicle body, a counterweight disposed at a rear portion of the vehicle body, a radiator disposed between the engine and the counterweight, and a radiator disposed between the engine and the radiator. In an industrial vehicle having a fan driven by an engine, a cylindrical sound absorbing member coaxial with a center line of the fan in a cooling air passage provided in the counterweight and immediately after the radiator. Noise reduction device for industrial vehicles.