JP5481086B2 - Engine blower - Google Patents

Description

  The present invention relates to an engine blower.

Conventionally, in a backpack type engine blower, intake air necessary for the engine is supplied via an air cleaner. The filter element in the air cleaner prevents dust from entering the engine by removing dust such as dust (for example, Patent Document 1). When dust is collected in the element, engine performance deteriorates due to a decrease in intake air, so that maintenance such as cleaning and replacement of the filter element is necessary. For this reason, it is known to equip an air cleaner with a larger element size for the purpose of reducing the frequency of maintenance.
JP 2004-308273 A

  However, because the engine blower is used while blowing out the wind, the wind blows up the dust, so it will be used in an environment where it is easier to suck in the dust, and the maintenance frequency will not decrease as expected. There's a problem. In addition, the development of a large air volume engine blower increases the amount of dust that rises in proportion, so a larger air cleaner is required in consideration of the maintenance interval of the air cleaner, resulting in problems of space and weight. .

  An object of the present invention is to provide an engine blower that can reduce the frequency of maintenance of an air cleaner and can reduce the size of the air cleaner.

An engine blower according to the present invention includes an engine, a fan that is rotationally driven by the engine, and a volute case that has a suction hole, and the fan is positioned between the suction hole and the engine and accommodated therein. And an air pipe connected to the volute case, and an air blowing space is provided on the outer peripheral side of the volute case to blow in the sucked air, and the volute case includes the air blowing space. An air passage opening is provided for communicating between the vicinity of the fan outer peripheral side and an air cleaner for cleaning intake air to the engine, and the air passage opening communicates with the air cleaner via a duct provided in the volute case , The air passage port is located between the vicinity of the fan outer peripheral side of the air blowing space and the suction port .

  In the engine blower according to the present invention, a flat portion corresponding to a blade tip of the fan is provided between the air blowing space of the volute case and the suction hole, and one end side includes the flat portion and the air blowing space includes the flat portion. An air passage is formed in communication with the vicinity of the fan outer periphery and the other end of the air passage is in communication with the air passage port, and the air cleaner is in communication with the vicinity of the outer periphery of the fan in the air blowing space through the air passage. Features.

  In the engine blower of the present invention, the fan is a closed type having an annular shroud, and the air passage is formed by the flat portion and the shroud.

  In the engine blower according to the present invention, the air cleaner is provided with a pressure adjusting hole for reducing the pressure of the intake air.

  According to the present invention, the volute case is provided with an air passage opening that communicates the vicinity of the fan periphery with the air cleaner, so that the dust is centrifuged using the fan, and the air from which the dust has been separated is removed from the air. Supply to the engine from the passage opening. Thereby, since air with less dust passes through the air cleaner and is supplied to the engine, clogging of the air cleaner can be prevented, and the frequency of maintenance can be reduced. Further, the air cleaner can be downsized by significantly reducing the amount of dust trapped by the air cleaner.

  A flat portion is provided between the air blowing space and the suction hole. When the air cleaner is connected to the vicinity of the outer periphery of the fan in the air blowing space via the air passage made of the flat portion, the dust is centrifuged by the fan. In addition, since air is sucked from a narrower air passage, air with less dust can be sucked into the air cleaner.

  When the fan is a closed type having an annular shroud, the air passage is formed by a flat portion and a shroud. In other words, by forming a part of the air passage with a fan shroud, the air passage can have a simple structure, and the structure of the volute case can be simplified and manufactured easily.

  Normally, the inside of the volute case is in a pressurized state, and setting the carburetor becomes difficult if the pressurized air is supplied to the engine as it is. However, by providing a pressure adjusting hole for reducing the pressure of the intake air in the air cleaner, the pressure of the intake air can be lowered and the carburetor can be easily adjusted.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view of the engine blower 1 according to the present embodiment as viewed from the back side (back side with respect to the worker), and FIG. 2 is a view of the engine blower from the front side (front side with respect to the worker). FIG.
As shown in FIGS. 1 and 2, the engine blower 1 includes a frame 2, a blower body 3 supported by the frame 2, and a wind pipe (not shown) connected to the blower body 3.

  The frame 2 includes a backrest portion 21 to which a shoulder belt is attached and abuts against a user's back, and a pedestal portion 22 that extends from the lower portion of the backrest portion 21 in a direction orthogonal to the backrest portion 21, and has a side view L It is formed in a letter shape. An operation handle 7 (FIG. 2) is rotatably attached to the backrest portion 21. During operation, the operation handle 7 is tilted forward (left side in the figure), and the operation handle 7 is operated to perform an output operation of the engine 31 of the blower body 3.

  The blower body 3 includes an engine 31, a fan 37 (FIG. 3 and FIG. 4) driven by the engine 31, a volute case 32 to which the engine 31 is attached on the back side, a fuel tank 33, and fuel from the fuel tank 33. And a carburetor 34 for generating an air-fuel mixture by intake air, and a muffler 35 for discharging the exhaust gas to the outside while silencing.

  Such a blower body 3 is supported by the gantry 22 via left and right vibration isolation rubbers 36A and 36B provided under the volute case 32, and is also provided with an anti-vibration rubber (not shown) provided above the volute case 32. And is supported at three points with respect to the frame 2. In the blower body 3, when the fan 37 is driven by the engine 31 to generate compressed air, the compressed air is sent from the volute case 32 to the elbow 5 (FIG. 3) connected to the volute case 32. It will be ejected from the connected wind pipe.

FIG. 3 is a perspective view of the blower body 3. FIG. 4 is a cross-sectional view of a main part of the blower body 3.
The volute case 32 of the blower body 3 has a halved structure and is formed of a case body 32A to which the engine 31 is attached and a volute cover 32B to be attached to the case body 32A by screws 32C. A fan 37 is accommodated in the volute case 32.

  The fan 37 is formed in a disc shape and is fixed to the output shaft of the engine 31, a plurality of blades 37C erected at predetermined intervals along the circumferential direction on one side of the hub 37B, and the blade 37C. An annular shroud 38 is provided so as to cover the tip, and both ends of the blade 37C are of a closed type covered with the hub 37B and the shroud 38.

  A circular air suction hole 32D is provided at the center of the volute cover 32B constituting the blower body 3. The air sucked into the suction hole 32D passes through the net 37A provided between the frame 2 and the blower body 3, so that large foreign matters such as fallen leaves are captured by the net 37A and do not enter the blower body 3. It has become. A funnel 39 for smoothly taking air into the suction hole 32D is provided on the outer peripheral portion of the suction hole 32D. The funnel 39 is formed in an arc shape in cross section, and an air reservoir 39C is formed on the inner side.

Between the funnel 39 and the curved surface portion 32F forming the outer peripheral side of the volute cover 32B, a flat portion 39G facing the shroud 38 of the fan 37 with a predetermined gap is formed. An air passage 39B is formed by the flat portion 39G and the shroud 38. An air passage 39B communicates, in particular, the vicinity of the outer periphery of the fan 37 of the air blowing space 32H provided on the outer peripheral side of the volute case 32 with the air reservoir 39C.
The funnel 39 is provided with an air passage port 39A penetrating inside and outside. As will be described later, the air guided to the air reservoir 39C through the air passage 39B flows into the air cleaner 4 for cleaning the intake air of the engine 31 through the air passage port 39A.

  The air cleaner 4 has a rectangular box shape including a lower case 4 </ b> A, an upper cover 4 </ b> B, and a filter element 41, and is placed on the upper part of the volute case 32. The lower case 4A of the air cleaner 4 is screwed to the mounting portion 32E of the volute case 32, and the upper cover 4B is fixed to the lower case 4A with a knob bolt 4C. The filter element 41 is placed so as to cover the opening 4D provided in the lower case 4A.

  Further, on one long side of the air cleaner 4, a pressure adjusting hole 42 for adjusting the pressure of intake air by communicating the inside and outside of the air cleaner 4 is provided. On the long side facing the pressure adjusting hole 42, a pair of cleaner portion suction ports 43 for sucking the air sucked from the fan 37 into the air cleaner 4 is provided. A hollow guide member 45 is attached at a position corresponding to the cleaner section suction port 43. The front end of the duct 44 is located in the lower opening portion of the guide member 45. By the duct 44 and the guide member 45, the inside of the air cleaner 4 and the air passage port 39A described above communicate with each other.

  The duct 44 includes a U-shaped, bifurcated U-shaped cover portion 44A and a cylindrical duct portion 44B, and is screwed to the volute case 32 at three points. The cover portion 44A of the duct 44 forms a flow path together with the wall portion 33A formed integrally with the volute cover 32B. The duct portion 44B is integrally provided at an end portion of the cover portion 44A. Via this duct 44 and the guide member 45, air that has been centrifuged in the volute case 32 to remove dust is supplied to the air cleaner 4.

  According to the engine blower 1 described above, the dust sucked together with the air from the suction hole 32D of the volute case 32 is separated to the outer peripheral side of the ventilation space 32H of the volute case 32 by the centrifugal separation action by the rotation of the fan 37. In the vicinity of the outer periphery of the fan 37, that is, the inner side of the air blowing space 32H, clean air from which dust is removed flows.

Here, since the dust is centrifuged by the fan 37 and sucked from the narrow air passage 39B, the dust is more difficult to enter.
At this time, when the intake process is started by the engine 31, the air pushed into the air passage 39B due to the negative pressure generated on the engine 31 side is pressurized while the air passage 39B, the air passage port 39A, and the duct 44 are pressurized. The air cleaner 4 and the cab side duct 6 (FIG. 3) supply the carburetor 34 as intake air.

  In this process, in the air cleaner 4, a slight amount of dust that could not be separated by centrifugation in the volute case 32 is collected by the filter element 41. That is, the dust collected by the filter element 41 is a very small amount of dust that could not be completely centrifuged in the volute case 32. Therefore, clogging of the filter element 41 can be suppressed, and the maintenance interval of the air cleaner 4 can be increased. In addition, the air cleaner 4 can be reduced in size.

By the way, the intake air drawn into the air cleaner 4 is pressurized (supercharged). However, since it is difficult to set the carburetor 34 in the supercharged state, the intake pressure (supercharge pressure) is lowered. There is a need. In order to reduce the supercharging pressure, the aforementioned pressure adjusting hole 42 is provided. A part of the intake air drawn into the air cleaner 4 in a supercharged state is discharged from the pressure adjusting hole 42, and the air inside the air cleaner 4 is reduced to an appropriate pressure and supplied to the carburetor 34. Furthermore, part of the dust that could not be separated from the pressure adjusting hole 42 is also discharged.

[Modification of Embodiment]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, the fan 37 of the above embodiment is provided with the shroud 38, but may be an open type without a shroud as shown in FIG.
In general, an engine blower using an open type fan 37 is not formed to be equivalent to the air passage 39B of the above-described embodiment. For this reason, the air between the flat part of the volute case 32 and the fan 37 is sucked by the fan 37, and the air is sucked in without being centrifuged, so that dust easily enters.
On the other hand, in the present modification, a first flat portion 39D is provided between the funnel 39 and the curved surface portion 32F, and a second flat portion 39E is provided between the first flat portion 39D and the fan 37. Is provided. The first flat portion 39D and the second flat portion 39E form an air passage 39B similar to that in the above-described embodiment.
Thus, in the open type fan 37 as well, the dust is centrifuged by providing the second flat portion 39E, and it becomes difficult for the dust to enter because the air is sucked from the narrow passage, and the same effect as the closed type fan 37 is obtained. Can be obtained.

  Furthermore, the air passage port 39A may be provided at the end of the curved surface portion 32F near the fan 37. Also in this case, air that has been centrifuged in the volute case 32 and from which dust has been removed can be drawn in from the air passage port 39A, and the object of the present invention can be sufficiently achieved.

  The present invention can be used for an engine blower.

The perspective view which looked at the engine blower concerning this embodiment from the back side The perspective view which looked at the engine blower from the front side. The perspective view of a blower main body. Sectional drawing of the principal part of a blower main body. Sectional drawing of the principal part of the modification of an engine blower.

  DESCRIPTION OF SYMBOLS 1 ... Engine blower, 2 ... Frame, 3 ... Blower main body, 4 ... Air cleaner, 31 ... Engine, 32 ... Volute case, 32D ... Suction hole, 32H ... Air blowing space, 37 ... Fan, 37C ... Blade, 38 ... Shroud, 39A ... air passage port, 39B ... air passage, 39D ... first flat part, 39E ... second flat part, 39G ... flat part, 42 ... pressure adjusting hole.

Claims (4)

Engine,
A fan that is rotationally driven by the engine;
A volute case having a suction hole, the fan being positioned between the suction hole and the engine and housed therein;
A wind pipe connected to the volute case;
On the outer peripheral side of the volute case is provided with a blowing space for blowing sucked air,
The volute case is provided with an air passage port that communicates the vicinity of the fan outer periphery side of the air blowing space with an air cleaner that cleans the intake air to the engine.
The air passage port communicates with the air cleaner through a duct provided in the volute case ,
The engine blower , wherein the air passage port is located between the vicinity of the fan outer peripheral side of the air blowing space and the suction port . The engine blower according to claim 1, wherein
A flat portion corresponding to the blade tip of the fan is provided between the air blowing space of the volute case and the suction hole,
Including this flat part, an air passage is formed in which one end side communicates with the vicinity of the fan outer periphery of the air blowing space, and the other end side communicates with the air passage port,
An engine blower, wherein the air cleaner and the vicinity of the outer periphery of the fan in the air blowing space communicate with each other via the air passage. The engine blower according to claim 2,
The fan is a closed type having an annular shroud,
The air passage is formed by the flat portion and the shroud. The engine blower according to any one of claims 1 to 3,
The air cleaner is provided with a pressure adjusting hole for reducing the pressure of the intake air.

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