JP2001099099A - Axial blower and air blast sprayer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an axial blower capable of restricting the generation of noise, and provide an air blast sprayer. SOLUTION: Plural holes 31 are arranged zigzag in a cylindrical fan case 23. The predetermined part α of a rotor blade 21 facing to the fan case 23 is not provided with the hole 31. On the other hand, the predetermined part βof a stator blade 29 fixed inside the fan case 23 is provided with the holes 31. The periphery of the fan case 23 is wrapped with the sound absorbing material 33 except for a part of an air duct bottom part 35. The periphery of the sound absorbing material 33 is wrapped with the cover material 37, and the fan case 23 is fixed to a carrier 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an axial blower and a speed sprayer, and more particularly, to a low noise axial blower and a speed sprayer.

[0002]

2. Description of the Related Art FIG. 9 shows an external view of a conventional speed sprayer. The speed sprayer 10 is a chemical spraying vehicle used in an orchard or the like. The speed sprayer 10 has a movable trolley 1, a driving unit 3 disposed on the trolley 1, a chemical tank 5, an engine room 7, and a jet head. 9 and a blower unit 11.

[0003] The blower unit 11 comprises an axial blower. Then, the air taken into the axial blower from the rear of the vehicle is sent to the jet head 9 in front at an increased speed.
Therefore, the mist from the plurality of nozzles 13 facing the jet head 9 is bent 90 degrees and transported in the direction perpendicular to the body.

[0004] The speed sprayer 10 radiates strong wind and fog in a fan-like manner above the fruit trees planted on the side of the running path and cultivated so as to cover the upper part of the orchard. The effect can be expected.

[0005] However, since a strong wind near 40 m / sec is generated at the outlet of the jet head 9, the noise of the axial blower in which the rotor blades 21 rotate at high speed is also large. In recent years, it has been said that noise has become a problem due to the invasion of residential areas around the field, but although there is recognition that noise reduction is one of the issues for manufacturers, no effective method has been found. Was.

[0006] In the axial blower of the speed sprayer 10, a rotor 21 driven by a motor (not shown) is disposed around a boss 27 in a cylindrical fan case 23 on the side of an air intake port 25, and is located downstream of the boss 27. Wings 29 are fan case 23
Is fixed inside. As a more specific shape,
For example, the inner diameter of the fan case 23 is 600 mm,
Outer diameter of 590 mm, the distance between the moving blade 21 and the stationary blade 29 is 10
mm. The bucket 21 is driven at 2300 revolutions per minute and obtains an air volume of about 260 cubic meters.

The main causes of the noise in the speed sprayer 10 are noise of a prime mover that drives the moving blade 21 at high speed, wind noise generated when the moving blade 21 cuts off air on the suction side, and moving blade 21. Wind noise when shearing the air between the blade and the stationary blade 29. Incidentally, the moving blades 21 and the stationary blades 29 are radially formed around the boss 27 by 10 and 13 blades, respectively.

[0008]

By the way, as a measure for reducing the noise, the rotating blades 21 and the stationary blades 29 are provided by lowering the rotation speed of the rotating blades 21 so as to allow a large-capacity motor.
Lowering the relative speed between the moving blades 21 and the stationary blades 29 so that the circumferential pitches of the moving blades 21 and the stationary blades 29 are not equal to each other.
It is conceivable to make the air flow in the air passage smooth. However, there are some that are difficult to realize in terms of cost and some that have limitations in terms of securing the blowing capacity.

[0009] The speed sprayer 10 is often used in a field where fruit trees are densely planted. Therefore, the turning radius is emphasized, and attention is focused only on the steering method and the shortening of the aircraft. No measures were taken to reduce the noise they would invite. Here, examples of prior art for noise reduction will be described. For example, in order to reduce the burden on the driver due to noise, there is a device in consideration of the arrangement of a driving engine and a fan engine (Japanese Utility Model Publication No. 63-49).
No. 325). However, this does not aim to reduce the noise of the entire working machine.

[0010] In order to reduce the noise of the work machine as a whole, the energy loss caused by changing the direction of the intake air parallel to the longitudinal direction of the machine to the direction perpendicular to the machine is considered. A chemical spray tube is installed on the blower side of the open-type blower, and the air resistance is extremely small, making it possible to use an engine with a smaller output than before, and these are superimposed to significantly reduce noise generation. There is also a proposal for a chemical sprayer that can be used (Japanese Utility Model Publication No. 61-35267). However, the air blowing direction was limited to the upper direction, and the structure was limited in spraying to the side.

Further, assuming that the rotation of the moving blade is a noise generating source, there is also a device in which a sound absorber is arranged so as to be orthogonal to the rotating shaft of the moving blade and opposed to the moving blade while securing a small air inflow gap ( Japanese Utility Model Laid-Open No. 3-59062). However, it cannot be denied that the sound absorbing body is obstructing the smooth flow of air, and an attempt to obtain a predetermined air blowing performance involves an increase in the output of the engine. There is a possibility that a sufficient noise reduction effect may not always be obtained.

Further, in a conventional speed sprayer using an axial flow blower, the joint between the fan case and the wind tunnel surrounding the fan case does not disturb the smooth flow in the air flow path. There have been proposals for inventions to eliminate the cause of noise generation (Japanese Patent Laid-Open No. Hei 8-2574).
No. 56, JP-A-11-93899). These can be said to be one approach to eliminating the cause of noise, but it is far from being a drastic improvement of the noise generated by the speed sprayer.

The present invention has been made in view of such conventional problems, and has as its object to provide a low-noise axial blower and a speed sprayer.

[0014]

SUMMARY OF THE INVENTION Therefore, the present invention (claim 1) provides a wind tunnel having an air inlet (25) at one end and an air outlet (39) at the other end, and a wind tunnel of the wind tunnel. A rotating drive source disposed on the other end side, a moving blade (21) disposed inside the wind tunnel and being rotationally driven by the rotating driving source; In an axial blower including a stationary blade (29) fixed inside the wind tunnel with a gap therebetween, the stationary blade (21) is removed except for a predetermined portion (α) of the moving blade (21) facing the wind turbine. 29) a sound absorbing means (23, 31) at at least one of a predetermined portion (β) facing the wind tunnel, around the air intake port (25) side and around the air discharge port (39) side of the wind tunnel. 33, 53, 63, 6
5) is provided.

The axial arrangement of the moving blade (21) and the stationary blade (29) does not matter. A predetermined portion (α) of the rotor blade (21) facing the wind tunnel is provided with a sound absorbing means (2) for securing a blowing pressure.
3, 31, 33, 53, 63, 65) are not provided. The sound absorbing means (23, 31) is provided at at least one of the predetermined portion (β) of the stationary blade (29) facing the wind tunnel, around the air intake port (25) and around the air discharge port (39). ,
33, 53, 63, 65).

[0016] The noise of the axial blower is that the air is a stationary blade (29).
Wind noise generated when sheared by the moving blade (21) is considered as one of the causes of noise, and the moving blade (2) having a relatively high relative speed is generated.
It is conceivable that a loud sound is generated as the outer edge of 1) is approached.

In order to send a large amount of air to the stationary blade (29) side, it is preferable that the gap between the inner periphery of the wind tunnel and the tip of the moving blade (21) is small. At this time, a vortex is generated between the moving blade (21) and the wind tunnel by air flowing upstream along the wind tunnel and air flowing downstream, but the vortex is generated at the air inlet (25) side of the wind tunnel. Sound absorbing means (23, 31, 3,
3, 53, 63, 65), the relative velocity of the axial flow along the inner circumferential surface of the wind tunnel is reduced, and the generation of vortices is reduced.

The sound generated near the inner surface of the wind tunnel and heading upstream rebounds on the inner surface of the wind tunnel facing the moving blade (21), and the sound absorbing means (2) disposed upstream of the moving blade (21).
3, 31, 33, 53, 63, 65), the interference action and energy attenuation are promoted, and as a result, the air intake port (2
5) A noise reduction effect on the side is produced.

The sound absorbing means (23, 31, 33, 53, 63, 65) disposed downstream of the moving blade (21) and / or a predetermined portion of the stationary blade (29) opposed to the wind tunnel. β), the sound absorbing means (23, 31, 33, 53, 63,
65), the pulsation of the pressurized air which is increased by sandwiching the air between the stationary blades (29) and the moving blades (21) and the wind noise generated at the time of the pulsation of the compressed air, and the energy attenuation. And reduce noise as a result.

Further, according to the present invention (claim 2), the sound absorbing means (23, 31, 33, 53, 63, 65) has a predetermined length in the axial direction in which a plurality of holes (31) are provided. A sound absorbing material that covers a fan case (23, 53) and / or a whole or a part of an outer periphery of the fan case (23, 53) and / or a periphery of the wind tunnel exceeding the predetermined length of the fan case (23, 53). (33).

The fan cases (23, 53) can be disposed over the entire length of the wind tunnel in the axial direction, but may be disposed for a predetermined length. A sound absorbing material (33) is provided on the outer periphery of the fan cases (23, 53). However, when the fan cases (23, 53) are provided by a predetermined length, the sound absorbing material (33) may be provided beyond the predetermined length. The sound absorbing material (33) is provided so as to cover all or a part of the periphery of the wind tunnel. The reason for this is that it is assumed that there is little influence of the direct sound on the outside or that it is difficult to arrange the sound absorbing material (33) due to the structure, as in the case of the wind tunnel bottom (35).

The reason why the plurality of holes (31) are provided in the fan case (23, 53) is that the fan case (23, 53)
The sound absorbing material (33) is held from the inside by the
3) is protected from deterioration due to high-speed air flow or pulsation.

Further, the present invention (claim 3) is characterized in that the outer periphery of the sound absorbing material (33) is covered with a covering (37). Due to this, by the covering (37),
The sound absorbing material (33) can be held from the outside.

Further, according to the present invention (claim 4), a bell mouth portion (41) gradually expanding outward is provided at the end of the wind tunnel or at the end of the fan case (23, 53). Said cover (37) being disposed at one end and the other end of a body;
Is characterized in that it surrounds between the outer edges of the one end and the other end of the bell mouth portion (41).

[0025] Thus, the support of the sound absorbing material (33) wound around the fan cases (23, 53) of the blower unit and the like can be ensured, the appearance of the blower can be made smooth, and trees and the like that come into contact during operation can be obtained. Breakage can be prevented.

Further, according to the present invention (claim 5), the sound absorbing means (23) provided around the air suction port (25) side of the wind tunnel and the air discharge port (39) side of the wind tunnel. , 3
1, 33, 53, 63, 65) and the bucket (21)
And the predetermined portion (α, β) to which the stationary blade (29) belongs
Are configured as divided units, and the unit is detachably connected to the predetermined portions (α, β) to which the moving blades (21) and the stationary blades (29) belong. .

As described above, the sound absorbing means (23, 31, 3)
By preparing the units provided with (3, 53, 63, 65) in advance, the axial blower can be easily assembled. Also, the situation in the work area (for example,
It is also possible to selectively use the unit according to the requirement of turning performance in work).

Further, according to the present invention (claim 6), the sound absorbing material (33) is a sponge body. The sound absorbing material (33) is, for example, a porous body called urethane foam.

Further, according to the present invention (claim 7), the sound absorbing material (33) is in a cotton state made of fine fibers. The sound absorbing material (33) may be, for example, a thin metal wire of glass wool or aluminum, or a cotton or a layer of felt.

Further, according to the present invention (claim 8), the covering (37) and / or the fan cases (23, 53) are constituted by a net.

Further, the present invention (claim 9) is characterized in that the sound absorbing material (33) has a honeycomb structure (63, 65) having an open end (65) facing the inside of the wind tunnel.

Further, the present invention (claim 10) is a speed sprayer, wherein the speed sprayer is provided with the axial blower according to claim 1, 2, 3, 4, 5, 6, 7, 8 or 9. It is characterized by being mounted.

[0033]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of an axial blower according to a first embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA in FIG. Note that the same components as those in FIG. 9 are denoted by the same reference numerals, and description thereof will be omitted.

In FIGS. 1 and 2, a plurality of holes 31 are arranged in a zigzag manner in a cylindrical fan case 23 as shown in FIG. The hole 31 is not provided in a predetermined portion α of the bucket 21 facing the fan case 23. On the other hand, the stationary blade 2 fixed inside the fan case 23
The hole 31 is provided in the predetermined portion β of the reference numeral 9.

On the outer periphery of the fan case 23, a wind tunnel bottom 3 is provided.
Except for a part of 5, a sound absorbing material 33 is wound. Sound absorbing material 3
A cover 37 is wound around the outer circumference of the fan 3, and the fan case 23 is fixed to the carriage 1. The sound absorbing material 33 is a sponge body, and is slightly protruded from the hole 31 of the fan case 23 as shown in FIG.

In such a configuration, a vortex is generated between the moving blade 21 and the fan case 23 due to air flowing upstream and downstream along the fan case 23 without reaching the stationary blade side. However, as shown in FIG.
The sound absorbing material 33 is disposed from the upstream of the air inlet 1 to the air inlet 25, and a part of the sound absorbing material 33 faces the inside of the wind tunnel. The relative velocity of the axial flow along is reduced and vortex formation is mitigated. Then, the sound absorbing material 33 promotes the interference action and energy attenuation, and as a result, a noise reduction effect of the speed sprayer 10 behind the body of the speed sprayer 10 is generated.

On the other hand, in the sound absorbing material 33 (including the fan case 23 portion to which the stationary blade 29 is fixed) disposed downstream of the moving blade 21, air is supplied between the stationary blade 29 and the moving blade 21. Shear as if sandwiched. The sound absorbing material 33 promotes the interference action and energy attenuation with respect to the pulsation of the pressurized air thus increased and the wind noise generated at that time, and as a result, reduces noise.

Note that, as shown in FIG.
The bell mouth portions 41A and 41B which are gradually expanded toward the outside are disposed on the side of the air intake port 25 and the side of the air discharge port 39, respectively, and the folded pieces 43A and 43B are provided at the respective ends of the bell mouth portions 41A and 41B. Are formed circumferentially. Folded piece 43
A around the outer periphery of 43A, 43B, bolts 45A, 45
Fix with B. The sound absorbing material 33 may be provided between the cover 37 and the fan case 23.

Next, an axial blower according to a second embodiment of the present invention will be described. The second embodiment of the present invention is a first embodiment.
Unlike the embodiment, the axial length of the fan case 53 is limited to a predetermined length. FIG. 2 of a second embodiment of the present invention
FIG. 6 shows a cross-sectional view taken along the arrow corresponding to. The same elements as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.
With this configuration, a large area of the sound absorbing material 33 can directly contribute to sound absorption without passing through the fan case 53.

Next, an axial blower according to a third embodiment of the present invention will be described. The third embodiment of the present invention is the first embodiment.
The present embodiment differs from the embodiment in that a different sound absorbing material is provided.
FIG. 7 is a cross-sectional view of a third embodiment of the present invention, which corresponds to FIG. The same elements as those in FIG. 2 are denoted by the same reference numerals, and description thereof will be omitted.

In FIG. 7, the surroundings of the stationary blade 29 and the moving blade 21 are configured similarly to the second embodiment of the present invention. A sound absorbing material 63 is provided on the upstream side of the moving blade 21 and on the downstream side of the stationary blade 29. The sound absorbing material 63 has a honeycomb structure, and the open ends 65 are gathered toward the inside of the wind tunnel. Each element constituting the honeycomb structure is shaped like a straw, and sound is reflected within this element and causes interference to be attenuated.

The term “honeycomb structure” used herein means, for example, a porous surface which is a straight cross section of a tubular body such as a bundled straw, or a corrugated cardboard laminated in a layered manner by aligning the directions of corrugations. It also includes a structure having a porous surface having a corrugated cross section facing the air passage.

Next, an axial blower according to a fourth embodiment of the present invention will be described. In the fourth embodiment of the present invention, the axial blower is divided into three units in the axial direction to form a unit. FIG. 8 shows a configuration diagram of an upstream unit (the downstream unit of the stationary blade 29 has the same shape) of the moving blade 21 according to the fourth embodiment of the present invention. However, a predetermined portion (portion corresponding to α and β in FIG. 2) to which the stationary blade 29 and the moving blade 21 belong is an integrated unit.

The three-divided unit can be detachably connected and is easily assembled. Further, versatility such as making the sound absorbing material different for each unit can be provided according to the capacity and configuration of the axial blower. The type, material and density of the sound absorbing material can be changed.

Next, the noise was actually measured using the speed sprayer 10 equipped with the axial blower according to the first embodiment of the present invention. The noise measurement by the speed sprayer 10 is performed at a point 10 m away from the front, back, left and right of the machine.
The test was performed at a point 1 m behind and near the driver's ear. As a result, in comparison of the noise measurement values of the speed sprayer according to the present invention and the corresponding conventional machine, reduction was confirmed at all points. In particular, a remarkable reduction value was obtained behind the speed sprayer.

The axial length of the sound absorbing material 33 provided before and after the stationary blade 29 and the moving blade 21 was set to 150 mm. The sound absorbing material used was a sponge body. The cover 37 for enclosing the sound absorbing material was made of a steel plate. The holes 31 of the fan case 23 were staggered at intervals of 20 mm. The present invention is also applicable to a blower cylinder of an engine blower, a centrifugal blower, and the like.

[0047]

As described above, according to the present invention, the predetermined portion (β) of the stator vane (29) facing the wind tunnel, the periphery of the wind tunnel at the side of the air intake port (25), and the air discharge port (39). Since the sound absorbing means (23, 31, 33, 53, 63, 65) are disposed around the side, the pulsation of the compressed air generated between the stationary blade (29) and the moving blade (21) and the wind noise generated at that time Etc.
Interference and energy attenuation are promoted, and as a result, noise can be reduced.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of an axial blower according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG.

FIG. 3 Example of arrangement of holes in fan case

Fig. 4 Installation of sound absorbing material

FIG. 5 Example of arrangement of sound absorbing material

FIG. 6 is a configuration diagram of a second embodiment of the present invention.

FIG. 7 is a configuration diagram of a third embodiment of the present invention.

FIG. 8 is a configuration diagram of an upstream unit according to a fourth embodiment of the present invention.

FIG. 9 is an external view of a conventional speed sprayer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Moving blade 23, 53 Fan case 25 Air suction port 29 Stator blade 31 Hole 33, 63 Sound absorbing material 37 Coating body 39 Air discharge port 41 (41A, 41B) Bell mouth part 65 Open end

Claims (10)

[Claims] 1. A wind tunnel having an air inlet (25) at one end and an air outlet (39) at the other end, a rotary drive source disposed at the other end of the wind tunnel, It is arranged inside the torso,
A rotor blade (21) rotationally driven by the rotary drive source;
In an axial flow blower including the moving blade (21) and a stationary blade (29) fixed inside the wind turbine with a slight gap in the axial direction, the moving blade (21) faces the wind turbine. Except for the predetermined portion (α), the predetermined portion (β) of the stator vane (29) facing the wind tunnel, either around the air intake port (25) or around the air discharge port (39) of the wind turbine. Or at least one sound absorbing means (23, 31, 33, 53, 63, 6
5) An axial blower, wherein the blower is disposed. 2. The sound absorbing means (23, 31, 33, 5)
3, 63, 65) are a fan case (23, 53) having a predetermined length in the axial direction in which a plurality of holes (31) are provided, an outer periphery of the fan case (23, 53) and / or the fan The axial flow blower according to claim 1, further comprising a sound absorbing material (33) covering all or a part of the periphery of the wind tunnel exceeding the predetermined length of the case (23, 53). 3. The axial blower according to claim 2, wherein the outer periphery of the sound absorbing material is covered with a cover. 4. The end of the wind tunnel or the fan case (2)
(3, 53) At the end, a bell mouth portion (41) gradually expanding outward is disposed at one end and the other end of the wind tunnel, and the cover (37) is attached to the bell mouth portion ( The axial flow blower according to claim 3, wherein the outer periphery of the one end and the other end of (41) is surrounded. 5. The sound absorbing means (23, 31, 33, 53, 63, 63) provided around the air inlet (25) side of the wind tunnel and the air discharge port (39) side of the wind tunnel. 65)
In addition, the predetermined portions (α, β) to which the moving blades (21) and the stationary blades (29) belong are each configured as a divided unit, and the unit includes the moving blades (21) and the stationary blades (29). 3) is detachably connectable to the predetermined portion (α, β) to which the item (1) belongs.
The axial flow blower according to 2, 3 or 4. 6. The axial blower according to claim 1, wherein the sound absorbing material is a sponge body. 7. The axial flow blower according to claim 1, wherein the sound absorbing material (33) is in a cotton state made of fine fibers. 8. The shaft according to claim 1, wherein the cover (37) and / or the fan case (23, 53) are nets. Flow blower. 9. The sound absorbing material (33) has a honeycomb structure (63, 65) having an open end (65) facing the inside of the wind tunnel. 7. The axial blower according to 7 or 8. 10. The method of claim 1, 2, 3, 4, 5, 6, 7,
A speed sprayer comprising the axial blower according to 8 or 9 mounted thereon.