JP2002303148A - Portable blast machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively cool a cylinder of an engine and an exhaust silencer without impairing the conventional air blasting performance, and to realize the reduction of noises in operation. SOLUTION: The cylinder 2 is cooled by the air A taken out of an air outlet 13 formed on a rear wall 12a of a fan case 12, the air A after cooling the cylinder 2 is guided to the circumference of an exhaust silencer 3 by a cylinder cover 5 and a silencer cover 6 to cool the exhaust silencer 3, and then the air is discharged to a rear part of the exhaust silencer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable device such as a blower cleaner which drives a blower by an engine such as an air-cooled two-cycle engine and blows and collects fallen leaves and dust by an air flow generated by the blower. It relates to a mold blower.

[0002]

2. Description of the Related Art In general, a portable air blower of this type usually has the portable air blower mounted on a back, for example, so that a worker using the portable air blower can move around and work easily. The backpack type that can be used is the mainstream (see FIG. 6).

Here, the structure of the above-mentioned portable type blower will be described with reference to FIG. That is, the portable air blower 20 shown in FIG. 1 includes a backrest mount 21 on which a backpack band 22, 22 supported by both shoulders through both arms, an engine 23 mounted on the backrest mount 21, It has a blower 24, a flexible tube 26 connected to the outlet tube 25 of the blower 24, and an injection tube 27 connected to the flexible tube 26. The worker has the injection pipe 2
By operating the operation handle 28 attached to the base end side of the hand 7 by hand, the injection pipe 27 can be freely manipulated. By blowing the air flow from the tip of the injection pipe 27 to the fallen leaves and the dust M vigorously, the fallen leaves and the dust M can be blown and collected for cleaning, compared to the conventional cleaning work using a broom. ,
The cleaning work can be performed much more efficiently.

In this type of working machine, there is a demand to keep the surface temperature of the exhaust silencer and the temperature of exhaust gas discharged from its outlet as low as possible. Therefore,
For example, improvements are made as shown in the plan view of FIG.
FIG. 7 shows a blower 24 having a fan 29 and a fan case 30 accommodating the fan 29 and an engine E for driving the fan.
Cylinder 31, exhaust silencer 32 and air cleaner 3
3 is schematically shown. In this arrangement, most of the pressurized air generated by the drive of the fan 29 is introduced into the discharge pipe 25 through the volute portion 36 of the fan case 30 and used for the original cleaning of the blower. However, a part of the cylinder 31 is taken out from an air outlet 34 provided in the rear wall 30a of the fan case 30 and guided around the cylinder 31 so that the cylinder 31 is cooled.

Further, the rear wall 30 of the fan case 30
a is provided with another air extraction hole 35a, and the air extracted from the air extraction hole 35a is guided to the periphery of the exhaust silencer 32, whereby the exhaust silencer 32 is directly cooled, whereby the exhaust The surface temperature of the silencer 32 and the temperature of the exhaust gas discharged from its outlet can be kept as low as possible.

[0006] It is also known that an air outlet 35b corresponding to the air outlet 35a is provided at a position facing the exhaust silencer 32 in the volute portion 36 instead of the rear wall 30a of the fan case 30. (Japanese Patent Laid-Open No. 2000-7
3762). According to this, the fan case 30
Compared with the case where the air extraction hole 35a is provided in the rear wall 30a.
Since the amount of air blown out from the air outlet 35b is significantly increased, it is expected that the surface temperature of the exhaust silencer 32 and the temperature of the exhaust gas discharged from the outlet thereof will be further reduced.

[0007]

However, in the case where the air outlet holes 35a and 35b are provided in the rear wall 30a or the volute portion 36 of the fan case 30, the blowing performance inherent in this type of blower is greatly reduced. I do. This is particularly remarkable when the air extraction hole 35b is provided on the volute section 36 side. Also, originally, the cylinder 31
In addition to the air outlet 33 provided for cooling the
By newly providing the air extraction hole 35a or 35b,
Noise due to leakage of the fan rotation sound from the air extraction holes 35a or 35b and airflow noise of the air passing through the air extraction holes 35a and 35b are generated.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and efficiently reduces cylinders of an engine and an exhaust silencer without reducing the blowing performance that a portable blower should have. It is an object of the present invention to provide a portable blower that cools and reduces noise during use.

[0009]

In order to achieve the above object, a portable blower according to the present invention comprises a blower having a fan covered by a fan case and an engine for driving the blower. A blower, wherein a cylinder of the engine is arranged to face an air outlet provided on a rear wall of the fan case, and an exhaust silencer is connected to one side of the cylinder; A cylinder cover that covers the upper side, the other side, and the rear side of the cylinder, and guides the air taken out from the air outlet to the exhaust muffler through the periphery of the cylinder; and at least one of the upper side, the front side, and one side of the exhaust muffler. And a muffler cover for exhausting the air derived from the cylinder cover to the rear outside through the periphery of the exhaust muffler.

According to this structure, the air taken out from the air outlet provided in the rear wall of the fan case is used for cooling the cylinder and is not discharged to the outside as it is, but is exhausted by the cylinder cover covering the cylinder. Since it is guided to the muffler side, and is discharged to the rear outside through the periphery of the exhaust muffler by the muffler cover, not only the cylinder but also the exhaust muffler can be efficiently cooled by the air. Therefore, the temperature of the exhaust gas also decreases.
For this reason, there is no need to newly provide a dedicated air outlet for cooling the exhaust silencer in the fan case, and the blowing performance that the blower originally has does not decrease. In addition, since there is no need for an air outlet for cooling the exhaust silencer in the fan case, leakage of fan noise and airflow noise generated when the working machine is operated can be suppressed, and noise can be reduced during use. .

Further, the portable air blower according to one embodiment of the present invention is configured such that the muffler cover further covers below the exhaust muffler.

According to this embodiment, the exhaust silencer is covered not only above, in front of and on one side of the exhaust silencer, but also below the exhaust silencer, so that the air flows to the lower surface of the exhaust silencer to enhance the cooling effect. At the same time, noise generated from the exhaust silencer is also reduced.

Further, a portable air blower according to another embodiment of the present invention has an exhaust port through which the exhaust silencer exhausts the exhaust gas of the engine to the rear, and the silencer cover includes the cylinder cover. By flowing the air led out of the exhaust port substantially parallel to the exhaust gas discharged from the discharge port through the periphery of the discharge port, the air is discharged backward while mixing the air with the exhaust gas.

According to this embodiment, the air after cooling the exhaust silencer around the exhaust silencer is exhausted rearward by the silencer cover, but the air is substantially removed from the exhaust gas from the exhaust port. Since the air is flowed in parallel and the temperature of the air is much lower than that of the exhaust gas of the engine, by mixing the two, the temperature of the exhaust gas is significantly reduced and the exhaust gas can be exhausted backward. it can. Thereby, the surface temperature of the exhaust silencer and the exhaust gas temperature can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A portable air blower according to an embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, the blower 1 has a fan 11 and a fan case 12 for accommodating the fan 11, and an engine E for driving the fan 11 to rotate is connected to a rear portion of the fan case 12. The cylinder 2 of the engine E is disposed at a position facing the air outlet 13 provided on the rear wall 12a of the fan case 12 from behind. An exhaust silencer 3 is connected to one side (right side) of the cylinder 2, and an intake device 4 including a carburetor and an air cleaner is connected to the other side (left side).
Is connected. The above basic configuration is almost the same as the basic configuration of the conventional portable blower.

Further, in the present invention, the pressurized air A taken from the air outlet 13 is guided to the exhaust silencer 3 through the periphery of the cylinder 2 by covering the upper side, the other side, and the rear side of the cylinder 2. A cylinder cover 5 is provided. In other words, instead of discharging the air A after cooling the cylinder 2 to the rear and outside as it is in the related art, the cylinder cover 5 has a function as a guide for the air A, and the air A is exhausted by the cylinder cover 5. It is configured to be guided to the muffler 3 side.

Here, as shown in FIG. 2, the cylinder cover 5 is located above the cylinder 2 except for the front face facing the air outlet 13 of the fan case 12 and one side face connected to the exhaust silencer 3. An air passage (cooling passage) is secured and covered between the other side (the side connected to the intake device 4 in FIG. 1) and the rear side and the outer peripheral surface of the cylinder 2. It has an upper wall 5a, a rear wall 5b, and another side wall 5c, and has one side 50 (muffler side) and the front 5
1 is open. The upper wall 5a is formed with an insertion hole 15 for a spark plug and an insertion hole 16 for a screw body to be described later for detachably attaching the cylinder cover 5 to the cylinder 2.

A muffler cover that covers the upper, front, one side and lower part of the exhaust silencer 3 and discharges the air A derived from the cylinder cover 5 to the rear outside through the periphery of the exhaust silencer 3. 6 are provided. Thereby, after the cylinder 2 is cooled, the air A guided to the exhaust silencer 3 side with the cylinder cover 5 as a guide, and further to the rear outside through the periphery of the exhaust silencer 3 with the silencer cover 6 as a guide. The exhaust muffler 3 is cooled by the air A in this process. Here, the muffler cover 6 is located above, on one side (the side not connected to the cylinder 2), in front (on the side facing the fan case 12) and below the exhaust muffler 3, at the outer peripheral surface of the exhaust muffler 3. Between the upper wall 6a and the one side wall 6 so as to cover the exhaust silencer 3.
b, a front wall 6c, and a lower wall 6d.
And a second cover piece 62 having the following. First
The upper wall 6a of the cover piece 61 has a through hole 4 for a screw body to be described later.
1 is formed, and an insertion hole 43 that matches the insertion hole 41 is formed on a stay 42 joined to the upper portion of the second cover piece 62 by, for example, welding.

As described above, the cylinder cover 5 having a function as a guide for guiding the air A taken out from the air outlet 13 in FIG. 1 from the outer peripheral surface of the cylinder to the outer peripheral surface of the exhaust silencer, and the muffler cover 6 And the air A taken out of the air outlet 13 of the fan case 12
Is the air outlet 13 → around the cylinder 2 → exhaust silencer 3
Is guided and discharged in the order from the periphery to the rear outside (the flow indicated by the arrow in the figure).

According to the above configuration, the air outlet 13 normally provided for cooling the cylinder 2 is effectively used as it is, and the air A taken out from the air outlet 13 is used.
Is not exhausted after the cylinder 2 is cooled, but the air A after the cylinder is cooled is finally guided to the exhaust muffler 3 by the cylinder cover 5 and the muffler cover 6.
The guided air A can be effectively used for cooling the exhaust silencer 3. Therefore, in order to cool the exhaust silencer 3, there is no need to provide the fan case 12 with a conventional air outlet 35a or 35b as shown in FIG. Does not decrease. In addition, since it is not necessary to provide a new air outlet other than the air outlet 13 with respect to the fan case 12, leakage of noise from the fan 11 and air flow noise passing through the air outlet are suppressed. Furthermore, since most of the exhaust silencer 3 and the cylinder 2 are covered with the covers 5 and 6, the radiation noise from the exhaust silencer 3 and the cylinder 2 can be effectively shut off.

The cylinder cover 5 may be divided into two or more parts. The silencer cover 6 may be divided into three or more, or may be formed integrally. Further, as a material of the constituent members of these covers, for example, a metal plate can be manufactured by sheet metal processing into a predetermined shape, but in order to further reduce noise, an iron plate is used as a core material and carbon is coated on both surfaces thereof. It is also possible to use a material having a soundproofing effect obtained by processing an object into a predetermined shape. The silencer cover 6 serves as a guide for the air A and also has a heat shielding property or a heat shielding property in consideration of the fact that the silencer cover 6 is normally disposed close to the fan case 12 formed of a synthetic resin such as polypropylene. Since the function of heat insulation is also important, when selecting the material, a material having a large heat shielding effect or heat insulation effect is selected.

FIG. 3 is a plan view showing the entire engine E of the portable air blower according to the present invention, and FIG. In FIG. 3, the cylinder 2 of the engine E has exhaust mufflers 3 arranged on both sides thereof.
And the intake device 4 are connected to each other, and a recoil starter 17 is attached to a rear portion and a spark plug 18 is attached to an upper portion. The cylinder 2 is arranged so as to face an air outlet 13 provided on a rear wall 12 a of the fan case 12. The cylinder cover 5 is supported on the top of the cylinder 2 by a screw body 45 inserted through the insertion hole 16 (FIG. 2), and the first cover piece 61 and the second cover piece 62 of the muffler cover 6.
Is supported above the silencer 3 by a screw body 46 inserted through the insertion holes 41 and 43 (FIG. 2). As shown in FIG.
The upper part of the exhaust silencer 3 is supported by the cylinder 2 and the lower part is
The screw body 47 is used to support the crankcase 19 below the cylinder 2.

In this portable air blower, as shown in FIG. 5, the cylinder 2 and the exhaust silencer 3 are usually covered with a shroud 7, so that a hand or skin does not directly touch a high heat-prone portion. To be considered. In FIGS. 3 and 4, for the sake of convenience, FIG.
FIG. 4 shows a case where most of the shroud 7 is omitted, and FIG. 4 shows a case where the entire shroud 7 is omitted.

In FIG. 3, the flow of the air A taken out from the air outlet 13 is guided by the cylinder cover 5 as indicated by the arrow, as shown in the principle diagram of FIG. Then, it is guided to the adjacent exhaust silencer 3 side. In this process, the cylinder 2
Cooled by. Subsequently, the air A guided to the exhaust muffler 3 is discharged rearward through the periphery of the exhaust muffler 3. At this time, in the exhaust gas B discharged to one side from the cylinder 2, HC, CO, NOx and the like in the exhaust gas are reduced to a certain level or less by an oxidation catalyst (not shown) in the exhaust silencer 3. Since the air A is guided around the exhaust silencer 3 whose surface temperature has increased due to the heat generated by the oxidation catalyst, the surface temperature of the exhaust silencer 3 can be reduced.

Further, as shown in FIG. 3 or FIG. 4, the muffler 3 of this embodiment has one side surface 3 opposite to the cylinder 2.
a between exhaust gas B and one side wall 6b of the muffler cover 6.
A discharge port 8 is formed on the one side surface 3a so as to flow backward. Therefore, exhaust gas B
Is the other side surface 3b on the cylinder side of the exhaust silencer 3 shown in FIG.
The exhaust gas enters the exhaust silencer 3 through an inlet 30 provided in the exhaust silencer 3, passes through the exhaust silencer 3, and is exhausted rearward through an exhaust port 8. At this time, as shown in FIG. Is
Guided by a guide portion 20 provided on the first cover piece 61 of the muffler cover 6 so as to protrude rearward, the air flows substantially rearward in parallel with each other, and is sufficiently mixed around the exhaust outlet 7a of the shroud 7 with the outside. Is discharged to as a result,
The temperature of the exhaust gas B at the exhaust outlet 7a can be reduced.

[0027]

As described above, according to the portable air blower according to the present invention, a part of the air taken out from the air outlet provided in the fan case is supplied to the air for cooling the cylinder and the exhaust silencer. Can be used effectively. For this reason, it is not necessary to newly provide a dedicated air extraction hole in the fan case to cool the exhaust silencer. Leakage of fan noise and generation of airflow noise are suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a portable air blower according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a main part of the portable air blower according to the embodiment.

FIG. 3 is a plan view showing an engine of the portable blower according to the embodiment.

FIG. 4 is a rear view showing the engine of the portable blower according to the embodiment.

FIG. 5 is a rear view showing a state in which a shroud is attached to the portable blower according to the embodiment.

FIG. 6 is a perspective view showing a use state of the portable air blower.

FIG. 7 is a schematic plan view showing a conventional portable air blower.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Blower, 11 ... Fan, 12 ... Fan case, 12
a ... rear wall, 13 ... air outlet, 2 ... cylinder, 3 ... exhaust silencer, 4 ... air cleaner, 5 ... cylinder cover, 6 ...
Silencer cover, 7: shroud, 8: outlet, A: air

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Isao Yoshimizu, Inventor 1-1, Kawasaki-cho, Akashi-shi, Hyogo Kawasaki Heavy Industries, Ltd. Inside Akashi Factory (72) Inventor Junichi Miyamoto 1554-3, Onumada, Togane-shi, Chiba Maru Co., Ltd. 3G004 AA07 BA02 BA05 DA15 DA22 EA04 EA05 FA04 FA07 GA01

Claims (3)

[Claims] 1. A portable air blower comprising: a fan having a fan covered by a fan case; and an engine for driving the fan, wherein a cylinder of the engine is provided on a rear wall of the fan case. An exhaust silencer is disposed opposite the outlet, and an exhaust silencer is connected to one side of the cylinder, and further covers an upper side, another side, and a rear side of the cylinder;
A cylinder cover that guides the air taken out from the air outlet to the exhaust muffler through the periphery of the cylinder, and covers at least an upper side, a front side, and one side of the exhaust muffler, and is led out of the cylinder cover. A portable air blower having a silencer cover for discharging air to the outside of the rear through the periphery of the exhaust silencer. 2. The portable air blower according to claim 1, wherein the muffler cover further covers a lower portion of the exhaust muffler. 3. The exhaust muffler according to claim 2, wherein the exhaust silencer has an exhaust port for exhausting exhaust gas from an engine to a rear side, and the muffler cover is configured to supply air drawn from the cylinder cover to the periphery of the exhaust port. A portable air blower configured to discharge the air rearward while mixing the air with the exhaust gas by flowing the exhaust gas substantially parallel to the exhaust gas passing through the outlet.