JP3703658B2 - Snow blower blower housing structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a noise reduction technique for a snowplow.
[0002]
[Prior art]
For example, a snow removal machine including an engine, an auger, and a blower is shown in Japanese Utility Model Publication No. 5-35152 “Snow Removal Machine”. FIG. 3 of this publication is reproduced in the next figure. However, the names and symbols of the components were changed.
[0003]
FIG. 8 is a cross-sectional view of a blower of a conventional snow remover. A blower housing 100 includes a cylindrical portion 102 that houses an impeller 101 and a discharge portion 103 that extends from the cylindrical portion 102 along a tangent line of the cylinder. . By rotating the impeller 101 at high speed in the clockwise direction, it is possible to apply a centrifugal force to the snow and project it through the discharge unit 103.
Since the blower efficiency decreases as the clearance between the cylindrical portion 102 and the impeller 101 increases, the clearance is reduced in order to increase the efficiency.
[0004]
[Problems to be solved by the invention]
Since the centrifugal force is proportional to the diameter of the impeller 101 and proportional to the square of the rotational speed, if the rotational speed is increased in a snow remover of a certain size, the processing capacity can be increased. In recent years, the rotation of the impeller 101 tends to be increased.
[0005]
As a result, although the amount of processed snow has increased significantly, there has been a new problem that noise from the blower housing 100 also increases.
[0006]
9 (a) and 9 (b) are noise graphs for a conventional snowplow.
(A) shows the noise investigated when the blower was stopped and only the engine was operated, the horizontal axis represents the frequency, and the vertical axis represents the noise.
(B) shows the noise examined when the blower is operated. Since both the engine and the blower are operated, the noise is generally larger than that of (a).
For example, comparing the noise at the frequency f on the horizontal axis of (a) and the noise at the frequency f on the horizontal axis of (b), it was found that (b) was larger by Δ1, that is, noisy. This Δ1 corresponds to the noise emitted from the blower housing 100.
[0007]
As described above, since the noise increases with the high speed rotation of the blower, it is difficult to improve the performance of the blower.
[0008]
[Means for Solving the Problems]
Therefore, as a result of various studies conducted by the present inventors to solve the above-described problems, in FIG. 8, the tongue-shaped portion 105 (the portion that forms a letter or V-shape at the boundary between the cylindrical portion 102 and the discharge portion 103). Air (wind) accelerated by the impeller 101 and snow (snow that enters the cylindrical portion 102 again without entering the discharge portion 103) collide with the blower terminology “tongue” or “tongue”. Thus, the present inventors have found that the collision sound at this time is a factor of the Δ1.
As described above, in order to maintain the blower performance, the clearance between the cylindrical portion 102 and the impeller 101 is set to be small. Therefore, when wind (air) or snow released by the discharge portion 103 enters a small clearance, a sound is generated. May also occur.
Then, when the shape of the tongue-like part 105 was improved variously and it experimented, it succeeded in achieving silence.
[0009]
Specifically, in claim 1, a blower housing is constituted by a cylindrical portion that houses the impeller and a discharge portion that extends along a tangent to the cylindrical portion, and the centrifugal force is applied to the snow by turning the impeller. In a snowplow of the type that projects this snow through the discharge part and shooter
In the tongue-shaped portion where the discharge portion intersects the cylindrical portion, a bulging groove on the V-bottom is formed in a slope shape in which the bulging margin decreases along the rotation of the impeller and bulges outward toward the cylindrical portion side. The groove is provided such that the apex of the groove extends horizontally and in the tangential direction of the cylindrical portion .
[0010]
Wind or snow that leaves the impeller and travels toward the tongue-like portion smoothly returns to the cylindrical portion along the bulging groove.
Therefore, it is possible to suppress the collision of wind and snow on the tongue-like portion, and it is possible to achieve noise reduction.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a side view of a snowplow according to the present invention. A snowplow 10 includes a crawler frame 16 provided with a free wheel 11 at a front portion and three lower rolling wheels 12, 13, and 14 at a lower portion, respectively. A vehicle body frame 21 is connected to the rear portion so as to be able to swing up and down, a snow removing portion 30 is attached to the front portion of the vehicle body frame 21, an engine 22 is mounted on the vehicle body frame 21, and a driving wheel 23 is attached to the rear portion of the vehicle body frame 21, A crawler belt 24 is wound around the driving wheel 23 and the idler wheel 11, the pivot shaft 25 connecting the vehicle body frame 21 to the crawler frame 16 is moved forward, the driving wheel 23 is moved rearward, and the last lower roller 14 is moved to the pivot shaft. The upper roller 26 is disposed on the crawler frame 16 so as to be disposed below the intermediate portion 25 and the drive wheel 23 and to support the crawler belt 24 between the pivot shaft 25 and the drive wheel 23. It is a crawler type vehicle, wherein.
[0012]
The snow removal unit 30 includes an auger 31, an impeller 32, a blower housing 60, a sled 34 and a shooter 35 which are driven by the engine 22 as basic elements. The engine 22, a small diameter pulley 36, a belt 37, a large diameter pulley 38, a drive shaft 39, the gear case 41, and the auger shaft 42 are transmitted in the order of the engine 22 to rotate the auger 31 and scrape the snow on the road in the direction of the drawing. Then, snow is projected through the shooter 35. 43 is an engine cover, 44 is an engine air cooling fan, 45 is an output pulley connected to the drive wheel 23, and 50 is an auger height adjusting hydraulic cylinder.
[0013]
2 is a cross-sectional view taken along the line 2-2 of FIG. 1, and the main components of the blower housing 60 are a cylindrical portion 61 that houses the impeller 32, and a discharge portion that extends from the cylindrical portion 61 along the tangent line of the cylinder. 62 and the tongue-shaped portion 63 where the discharge portion 62 intersects the cylindrical portion 61 bulges outward toward the cylindrical portion 61 and expands along the rotation of the impeller 32 (arrow (1)) (described later). 4 and the sloped bulging groove 64 in which the signs D1 and D2) in FIG. 4 decrease.
[0014]
FIG. 3 is a plan view of the blower housing according to the present invention. A triangular columnar member extending from the cylindrical portion 61 to the rectangular duct-shaped discharge portion 62 is a bulging groove forming member 65, and the bulging groove forming member 65 is shown in FIG. There is a bulging groove on the lower surface of the.
[0015]
FIG. 4 is a perspective view of the bulging groove forming member (first embodiment) according to the present invention. The bulging groove 64 formed in the bulging groove forming member 65 has a triangular cross section and the rotation of the impeller ( It indicates that the bulge allowance is a slope that decreases as D1 → D2 along the arrow (1).
[0016]
Next, the operation of the blower housing structure described above will be described.
In FIG. 2, when the impeller 32 is rotated as indicated by the arrow {circle around (1)}, wind or snow imparted with centrifugal force by the impeller 32 is directed to the tongue-like portion 63. Since the tongue-like portion 63 has a slope-like bulging groove 64, wind and snow smoothly move along the bulging groove 64 as shown by the arrow (2) and return to the cylindrical portion 61. Therefore, the tongue-like portion 63 does not cause a collision as in the prior art, and even if it collides, it becomes minor.
[0017]
If the clearance between the inner surface of the cylindrical portion 61 and the impeller 32 is increased, the collision sound can be reduced. However, an increase in clearance leads to a decrease in blower efficiency and a decrease in snow throwing performance. That is, the length L of the bulging groove 64 has a positive effect on noise reduction and a negative effect on blower efficiency. Therefore, the length L of the bulging groove 64 may be set in consideration of both noise reduction and blower efficiency.
[0018]
FIGS. 5A and 5B are comparative diagrams of noise.
(A) shows the noise of a comparative example and is the same graph as FIG.9 (b). That is, (a) the comparative example shows noise in the blower housing of FIG.
(B) shows the noise of the Example provided with the bulging groove | channel, and the noise is entirely smaller than (a).
For example, comparing the noise at the frequency F on the horizontal axis of (a) and the noise at the frequency F on the horizontal axis of (b), the noise level of (b) is lowered by Δ2.
Therefore, it can be said that the bulging groove 64 of the present invention has a silent effect, and it can be expected that the countermeasure can easily achieve a high speed rotation of the blower of the snowplow.
[0019]
Figure 6 is a reference diagram Rise Demizo forming member, protruding the groove forming member 65B is U-section member, forming the bulging grooves 64B indicates that exhibits an oblong rectangular cross section, and rotation of the impeller 32 It shows that the bulging allowance exhibits a slope shape that decreases as D1 → D2 along (circled numeral 1).
Since the bulging groove forming member 65B is a simple plate material in which a part of a rectangular duct is cut off, it can be manufactured easily and at low cost.
[0020]
FIG. 7 is a perspective view of a bulging groove forming member ( second embodiment) according to the present invention. The bulging groove forming member 65C is an arc cross-sectional member, and the formed bulging groove 64C has a substantially semicircular cross section. This indicates that the bulge allowance decreases as D1 → D2 along with the rotation of the impeller.
Since the bulging groove forming member 65C is a simple plate material obtained by cutting a part of a round duct, it can be manufactured easily and at low cost.
[0021]
On the other hand, since the bulging groove 64 of FIG. 4 has a triangular prism shape, the bottom is the V bottom. You can collect snow in such a V-bottom. On the other hand, since the bulging groove 64B in FIG. 6 has a rectangular cross section, there is a possibility that snow plays in a wide bottom range (reciprocates in the axial direction of the impeller). FIG. 4 is superior to FIG. 6 in that the snow is stably returned to the cylindrical portion 61.
The bulging groove 64 </ b> C having a semicircular cross section in FIG. 7 is intermediate between FIGS. 4 and 6.
Therefore, the bulging grooves 6 4, 6 4C may be appropriately selected, triangular, other semicircle, a trapezoid, an ellipse, but it may also be polygonal or pentagonal.
[0022]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
According to the first aspect of the present invention, the tongue-shaped portion where the discharge portion intersects the cylindrical portion is provided with a slope-shaped bulging groove that bulges outward toward the cylindrical portion and reduces the bulging allowance along the rotation of the impeller. The wind and snow from the impeller toward the tongue can be smoothly returned to the cylindrical portion along the bulge groove, and therefore, the collision of wind and snow on the tongue can be suppressed. Can be achieved.
As a result, the impeller can be rotated at a high speed up to a certain noise level, and the capacity of the snowplow can be easily increased.
[Brief description of the drawings]
FIG. 1 is a side view of a snowplow according to the present invention. FIG. 2 is a sectional view taken along line 2-2 in FIG. 1. FIG. 3 is a plan view of a blower housing according to the present invention. forming member (first embodiment) of a perspective view and FIG. 5 comparison diagram of noise [6] Rise Demizo members of reference view 7 bulging groove forming member according to the present invention (second embodiment) [Fig. 8] Cross-sectional view of a conventional snow blower blower [Fig. 9] Noise graph for a conventional snow remover [Explanation of symbols]
10 ... snowplow, 32 ... wheel, 60 ... blower housing, 61 ... cylindrical part, 62 ... discharge unit, 63 ... tongue, 6 4, 6 4C ... bulging grooves, 65,65B, 65C ... bulging groove Forming members, D1, D2,.

Claims (1)

A blower housing is constituted by a cylindrical portion for storing the impeller and a discharge portion extending along a tangent line of the cylindrical portion, and the impeller is rotated to apply centrifugal force to the snow, and this snow is supplied to the discharge portion and the shooter. In the type of snowplow that projects through
In the tongue-shaped portion where the discharge portion intersects the cylindrical portion, a bulging groove on the V-bottom is formed in a slope shape in which the bulging margin decreases along the rotation of the impeller and bulges outward toward the cylindrical portion side. A blower housing structure for a snowplow, wherein the top of the groove is provided horizontally and extends in the tangential direction of the cylindrical portion .

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