JP3778269B2 - Portable air blower - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a portable blower such as a blower cleaner that 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.
[0002]
[Prior art]
This type of portable air blower is usually a back carrying the portable air blower so that it can be carried on the back, for example, so that an operator using the portable air blower can move around and work easily. Formula types are mainstream (see FIG. 6).
[0003]
Here, the structure of the carrying type portable air blower will be described with reference to FIG. That is, the portable blower 20 shown in FIG. 1 includes a backpack 21 on which a backband 22, 22 supported by both shoulders through both arms, and an engine 23 mounted on the backpack 21. The blower 24 includes a flexible pipe 26 connected to the outlet pipe 25 of the blower 24 and an injection pipe 27 connected thereto. When the operator holds and operates the operation handle 28 attached to the proximal end side of the injection pipe 27, the injection pipe 27 can be freely operated. Then, by blowing the air flow from the tip of the injection pipe 27 against the fallen leaves and dust M, the fallen leaves and dust M can be blown up and cleaned, compared with a conventional cleaning operation using a broom. , Much more efficient cleaning work can be done.
[0004]
By the way, 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 the exhaust port as low as possible. Therefore, for example, improvements as shown in the plan view of FIG. 7 are made. FIG. 7 schematically shows an arrangement configuration of the fan 29 including the fan 29 and the fan case 30 that accommodates the fan 29, the cylinder 31 of the engine E that drives the fan 29, the exhaust silencer 32, and the air cleaner 33. In this arrangement, most of the pressurized air generated by driving the fan 29 is introduced into the discharge pipe 25 via the volute portion 36 of the fan case 30 and used for the original cleaning of the blower working machine. However, a part thereof is taken out from an air outlet 34 provided in the rear wall 30 a of the fan case 30 and guided to the periphery of the cylinder 31 to cool the cylinder 31.
[0005]
Further, another air extraction hole 35a is provided in the rear wall 30a of the fan case 30, and the air extracted from the air extraction hole 35a is guided to the periphery of the exhaust silencer 32 so that the exhaust silencer 32 is By directly cooling, the surface temperature of the exhaust silencer 32 and the temperature of exhaust gas discharged from the exhaust port can be suppressed as low as possible.
[0006]
Further, it is also known that an air extraction hole 35b corresponding to the air extraction hole 35a is provided in a position facing the exhaust silencer 32 in the volute 36 instead of the rear wall 30a of the fan case 30 (special feature). Open 2000-73762). According to this, compared with the case where the air extraction hole 35a is provided in the rear wall 30a of the fan case 30, the amount of air ejected from the air extraction hole 35b is remarkably increased. It is expected that the temperature and the temperature of the exhaust gas discharged from the discharge port will be kept lower.
[0007]
[Problems to be solved by the invention]
However, when the air extraction holes 35a and 35b are provided in the rear wall 30a or the volute portion 36 of the fan case 30, the air blowing performance inherent in this type of air working machine is significantly reduced. This is particularly noticeable when the air extraction hole 35b is provided on the volute 36 side. Further, in addition to the air outlet 34 originally provided for cooling the cylinder 31, a new air outlet hole 35a or 35b is provided, thereby leaking fan rotation sound from these air outlet holes 35a or 35b. And noise of airflow through the air extraction holes 35a and 35b are generated.
[0008]
The present invention has been made in view of the above-described problems, and efficiently cools the engine cylinder and the exhaust silencer without deteriorating the blowing performance that should originally be possessed as a portable blower working machine. An object of the present invention is to provide a portable air blower that achieves low noise during use.
[0009]
[Means for Solving the Problems]
In order to achieve the above-described object, a portable air blower according to the present invention is a portable air blower comprising a fan having a fan covered with a fan case, and an engine that drives the fan. An engine cylinder is disposed opposite to an air outlet provided on the rear wall of the fan case, and an exhaust silencer is connected to one side of the cylinder, and further above, outside and behind the cylinder. And a cylinder cover that guides the air taken out from the air outlet to the exhaust silencer through the periphery of the cylinder, and is supported by the exhaust silencer, at least above and forward and one side of the exhaust silencer covering a way, the air derived from the cylinder cover through the periphery of the exhaust muffler and a metallic silencer cover for discharging rearwardly outside, exhaust gas of the exhaust muffler engine Has a discharge port for discharging to the rear, the silencer cover has a guide portion 65 provided to protrude from one side wall to the rear, by the guiding of the guide portion, the air derived from the cylinder cover By flowing substantially parallel to the exhaust gas discharged from the discharge port through the periphery of the discharge port, the air is discharged backward from the exhaust outlet of the shroud while being mixed with the exhaust gas.
[0010]
According to this configuration, the air taken out from the air outlet provided in the rear wall of the fan case is used for cooling the cylinder, and then is not discharged to the outside as it is, but the exhaust silencer side is covered by the cylinder cover that covers the cylinder. And the exhaust silencer cover passes through the periphery of the exhaust silencer and is exhausted to the outside. Therefore, not only the cylinder but also the exhaust silencer can be efficiently cooled by the air. The gas temperature also decreases. For this reason, it is not necessary to newly provide a dedicated air extraction hole for cooling the exhaust silencer in the fan case, and the air blowing performance that is originally provided as a blower does not deteriorate. In addition, since the fan case does not require an air extraction hole for cooling the exhaust silencer, the fan noise leakage and airflow noise that occur during operation of the work equipment are suppressed, and low noise during use can be realized. . Further, the air after cooling the exhaust silencer through the periphery of the exhaust silencer is exhausted rearward by the silencer cover, but the air is caused to flow substantially parallel to the exhaust gas from the exhaust port, and the air Since the temperature of the exhaust gas is much lower than that of the exhaust gas of the engine, by mixing them, the temperature of the exhaust gas can be greatly lowered and discharged backward. Thereby, the surface temperature of the exhaust silencer and the exhaust gas temperature can be lowered.
[0011]
Moreover, the portable air blower according to an embodiment of the present invention is configured such that the silencer cover further covers the lower side of the exhaust silencer.
[0012]
According to this embodiment, the exhaust silencer is covered in addition to the upper part, the front part, and one side, as well as the lower part thereof, so that the air also flows into the lower surface of the exhaust silencer and the cooling effect is enhanced. Noise generated from the silencer is also reduced.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a portable air blower according to an embodiment of the present invention will be described with reference to FIG. 1 and FIG.
[0016]
In FIG. 1, the blower 1 includes a fan 11 and a fan case 12 that accommodates the fan 11, and an engine E that rotationally drives the fan 11 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 the rear. 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). About the above basic composition, it is almost the same as the basic composition in the conventional portable air blower.
[0017]
In the present invention, the cylinder cover 5 that covers the upper side, the other side, and the rear side of the cylinder 2 and guides the pressurized air A taken out from the air outlet 13 to the exhaust silencer 3 through the periphery of the cylinder 2. Is provided. That is, the air A after cooling the cylinder 2 is not discharged to the outside as it is in the conventional manner, but the cylinder cover 5 has a function as a guide for the air A, and the air is exhausted by the cylinder cover 5. It is configured to be guided to the silencer 3 side.
[0018]
Here, as shown in FIG. 2, the cylinder cover 5 is located above the cylinder 2 and on the other side except for the front surface facing the air outlet 13 of the fan case 12 and one side surface connected to the exhaust silencer 3. An air passage (cooling passage) is secured and covered with the outer peripheral surface of the cylinder 2 (on the side connected to the intake device 4 in FIG. 1) and the rear, and an upper wall 5a And the rear wall 5b and the other side wall 5c, and the one side portion 50 ( exhaust silencer 3 side) and the front portion 51 are open. The upper wall 5a is formed with a spark plug insertion hole 15 and a screw body insertion hole 16 to be described later for detachably attaching the cylinder cover 5 to the cylinder 2.
[0019]
Further, a silencer cover 6 is provided which covers the upper, front, one side and the lower side of the exhaust silencer 3 and discharges the air A led out from the cylinder cover 5 to the outside outside through the periphery of the exhaust silencer 3. ing. Thus, after the cylinder 2 is cooled, the air A guided to the exhaust silencer 3 side using the cylinder cover 5 as a guide, and further to the rear outside through the periphery of the exhaust silencer 3 using the silencer cover 6 as a guide. In this process, the exhaust silencer 3 is cooled by the air A. Here, the silencer cover 6 is located above the exhaust silencer 3, on one side (side not connected to the cylinder 2), forward (side facing the fan case 12), and below, on the outer peripheral surface of the exhaust silencer 3. An air passage (cooling passage) is secured between the exhaust cover and the exhaust silencer 3 so as to cover the first cover piece 61 having an upper wall 6a and one side wall 6b, and a front wall 6c. And a second cover piece 62 having a lower wall 6d. The upper wall 6a of the first cover piece 61 is formed with an insertion hole 41 of a screw body, which will be described later, and an insertion hole that matches the insertion hole 41 in a stay 42 joined to the upper portion of the second cover piece 62 by, for example, welding. 43 is formed.
[0020]
Thus, the cylinder cover 5 having a function as a guide for guiding the air A taken out from the air outlet 13 of FIG. 1 from the cylinder outer peripheral surface to the exhaust silencer outer peripheral surface, and the silencer cover 6 are provided. Thus, the air A taken out from the air outlet 13 of the fan case 12 is in the order of the air outlet 13 → the periphery of the cylinder 2 → the periphery of the exhaust silencer 3 → the rear outside (flow indicated by the arrow in the figure). Guided and discharged.
[0021]
According to the above configuration, the air outlet 13 that is 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 not discharged after the cylinder 2 is cooled. The air A after cooling the cylinder is finally led to the exhaust silencer 3 side by the cylinder cover 5 and the silencer cover 6, and the guided air A can be effectively used for cooling the exhaust silencer 3. . Therefore, since it is not necessary to provide the conventional air extraction hole 35a or 35b as shown in FIG. 7 in the fan case 12 in order to cool the exhaust silencer 3, the air blowing performance inherently possessed by the portable air blower is provided. Will not drop. Further, since it is not necessary to provide a new air extraction hole in addition to the air outlet 13 in the fan case 12, noise leakage of the fan 11 and airflow noise of the air 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 radiated sound from the exhaust silencer 3 and the cylinder 2 can be effectively blocked.
[0022]
The cylinder cover 5 may be divided into two or more. The silencer cover 6 may be divided into three or more, or may be formed integrally. Moreover, as a material of the constituent members of these covers, for example, a metal plate can be manufactured by means such as sheet metal processing into a predetermined shape. However, in order to further reduce noise, both sides are coated with carbon using an iron plate as a core material. A material having a soundproofing effect obtained by processing an object into a predetermined shape can be used. In addition to the role of the air silencer cover 6 as a guide for the air A, the silencer cover 6 is usually provided with a heat shielding property or a point where it is 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 the material is selected, a material having a large heat shielding effect or heat insulation effect is selected.
[0023]
FIG. 3 is a plan view showing the entire engine E of the portable blower according to the present invention, and FIG. 4 is a rear view of the engine E. In FIG. 3, an exhaust silencer 3 and an intake device 4 disposed on both sides of the engine 2 are connected to the cylinder 2 of the engine E, a recoil starter 17 is attached to the rear, and a spark plug 18 is attached to the upper part. Yes. The cylinder 2 is disposed so as to face the air outlet 13 provided in the rear wall 12a 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 silencer cover 6 are inserted into the insertion holes 41, 43. The screw body 46 inserted in (FIG. 2) is supported on the upper part of the silencer 3. As shown in FIG. 4, the upper part of the exhaust silencer 3 is supported by the cylinder 2, and the lower part is supported by a crankcase 19 below the cylinder 2 using a screw body 47.
[0024]
As shown in FIG. 5, in this portable blower, the cylinder 2 and the exhaust silencer 3 are usually covered with a shroud 7 so that hands and skin are not directly in contact with high heat-prone portions. To do. 3 and 4, for the sake of easy understanding of the internal structure, FIG. 3 shows that the most part of the shroud 7 is omitted, and FIG. 4 shows that the entire shroud 7 is omitted. ing.
[0025]
In FIG. 3, the air A taken out from the air outlet 13 is guided by the cylinder cover 5 as shown by the arrow as described in the principle diagram of FIG. It is guided to the exhaust silencer 3 side. In this process, the cylinder 2 is cooled by the air A. Subsequently, the air A guided to the exhaust silencer 3 side is exhausted rearward through the exhaust silencer 3. At this time, the exhaust gas B discharged to one side from the cylinder 2 is reduced in the exhaust silencer 3 by oxidization catalyst (not shown) to reduce HC, CO, NOx, etc. in the exhaust gas to a certain level or less. Since the air A is guided around the exhaust silencer 3 whose surface temperature is increased by the heat generated by the oxidation catalyst, the surface temperature of the exhaust silencer 3 can be lowered.
[0026]
Further, as shown in FIG. 3 or FIG. 4, the exhaust silencer 3 of the present embodiment is configured such that the exhaust gas B faces the rear side between the one side surface 3 a opposite to the cylinder 2 and the one side wall 6 b of the silencer cover 6. A discharge port 8 is formed on the one side surface 3a so as to face backward. Therefore, the exhaust gas B enters the exhaust silencer 3 from the introduction port 30 provided on the other side surface 3b of the exhaust silencer 3 shown in FIG. 2, passes through the exhaust silencer 3, and is exhausted rearward from the exhaust port 8. However, at this time, as shown in FIG. 3, the exhaust gas B and the air A are guided by the guide portion 65 provided to protrude rearward from the first cover piece 61 of the silencer cover 6, They flow rearward substantially parallel to each other, and are discharged to the outside in a sufficiently mixed state in the vicinity of the exhaust outlet 7a of the shroud 7. As a result, the temperature of the exhaust gas B at the exhaust outlet 7a can be lowered.
[0027]
【The invention's effect】
As described above, according to the portable blower according to the present invention, a part of the air taken out from the air outlet provided in the fan case can be effectively used as cooling air for the cylinder and the exhaust silencer. . For this reason, since it is not necessary to newly provide a dedicated air extraction hole in the fan case in order to cool the exhaust silencer, it is possible to prevent deterioration of the air blowing performance that the air blower originally has, and when the work machine is in operation. Leakage of fan noise and generation of airflow noise are suppressed. The air after cooling the exhaust silencer through the periphery of the exhaust silencer is caused to flow almost in parallel with the exhaust gas from the exhaust port, and the temperature of the air is much lower than the exhaust gas of the engine. Therefore, when both are mixed, the temperature of the exhaust gas can be greatly reduced and discharged backward. Thereby, the surface temperature of the exhaust silencer and the exhaust gas temperature can be lowered.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing a portable 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 the engine of the portable air blower according to the embodiment.
FIG. 4 is a rear view showing the engine of the portable air blower according to the embodiment.
FIG. 5 is a rear view showing a state in which a shroud is attached to the portable blower working machine according to the embodiment;
FIG. 6 is a perspective view showing a usage state of the portable blower working machine.
FIG. 7 is a schematic plan view showing a conventional portable blower working machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Blower, 11 ... Fan, 12 ... Fan case, 12a ... Rear wall, 13 ... Air intake, 2 ... Cylinder, 3 ... Exhaust silencer, 4 ... Air cleaner, 5 ... Cylinder cover, 6 ... Silencer cover, 7 ... shroud, 8 ... outlet, A ... air

Claims (2)

A portable blower working machine comprising a blower in which a fan is covered with a fan case, and an engine for driving the blower,
A cylinder of the engine is disposed opposite to an air outlet provided in a rear wall of the fan case;
And an exhaust silencer is connected to one side of the cylinder,
Furthermore, 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 silencer through the periphery of the cylinder;
A metal that is supported by the exhaust silencer and covers at least the upper part, the front, and one side of the exhaust silencer, and discharges the air led out from the cylinder cover to the outside outside through the periphery of the exhaust silencer . With a silencer cover
Furthermore, the cylinder and the exhaust silencer are covered with a shroud,
The exhaust silencer has an exhaust port for exhausting the exhaust gas of the engine rearward, and the silencer cover has a guide part provided to protrude rearward from one side wall, and the guide part guides the By flowing the air led out from the cylinder cover through the periphery of the exhaust port substantially in parallel with the exhaust gas exhausted from the exhaust port, the air is mixed into the exhaust gas and exhausted backward from the exhaust outlet of the shroud. A portable air blower configured to be.   The portable blower working device according to claim 1, wherein the silencer cover is configured to further cover a lower portion of the exhaust silencer.

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