JP3165459U - Blower - Google Patents

Abstract

[PROBLEMS] To provide a low-power blower that improves work efficiency in a manhole and has excellent transportability. A blower (11) has a box-shaped housing (12), an electric fan mounted inside the housing (12), one end of which is detachably connected to the housing (12), and the other end arranged in a work site (102). And a tubular air duct 15 to be used. Here, the electric fan has a power consumption of 160 W or less, a maximum static pressure of 550 Pa or more, and a maximum air volume of 10 m3 / min or more. Further, the diameter of the air duct 15 is 150 mm or less. [Selection diagram] Fig. 1

Description

  The present invention relates to a blower, and more particularly, to a blower used at a work site closed from outside air such as the inside of a manhole.

  When the work site is closed from the outside air, such as in a manhole, there is a risk of a decrease in the oxygen concentration at the work site, so it is necessary to send the outside air to the work site during the work. is there. For example, a blower described in Japanese Utility Model Laid-Open No. 5-87288 (Patent Document 1) is disclosed as a blower for work sites used for such applications. A blower described in Patent Document 1 includes a fan that sucks and exhausts air by driving a motor, a bellows-like air duct that is connected to the fan and sucks and exhausts air into a manhole, a storage unit that stores the air duct, and a portable handle Department. According to this configuration, since the bellows-shaped air duct can be housed in the housing portion, it is possible to provide a blower with better transportability.

Japanese Utility Model Publication No. 5-87288

  Many conventional blowers for work sites including the blower described in Patent Document 1 were provided with a blow duct having a diameter of about 300 mm. This is because, if the diameter of the air duct is not set to this level, it is difficult to ensure a sufficient air volume due to pressure loss that occurs when air flows in the air duct. However, the use of the air duct having such a diameter has caused the following problems in the field work. In other words, the current standard manhole in Japan has a diameter of about 600 mm. For this reason, if the ventilation duct which has the above diameters is inserted in a manhole, when an operator raises / lowers the inside of a manhole, it will become a big trouble. Thereby, working efficiency will fall.

  In addition, there have been many requests for improving the convenience of transporting the apparatus when moving on the site by reducing the size and size of the blower.

  Therefore, in view of the above problems, an object of the present invention is to provide a low-power blower that improves work efficiency in a manhole and is more excellent in transportability.

A blower according to the present invention is used to send outside air into a work site closed from outside air, and has a box-like housing having an air suction opening and an air blowing opening and having a handle on the upper surface. And an electric fan attached to the air outlet from the inside of the housing, and a tubular air duct having one end detachably connected to the air outlet and the other end arranged in the work site. Here, the electric fan has a power consumption of 160 W or less, a maximum static pressure of 550 Pa or more, and a maximum air volume of 10 m ³ / min or more. Furthermore, the diameter of the air duct is 150 mm or less.

  According to this configuration, even when an air duct having a diameter of 150 mm or less, in which the pressure loss is relatively large, is applied to the blower by applying the electric fan having the air blowing capacity that brings the static pressure and the air volume as described above. It is possible to blow a sufficient air volume into the work site. That is, a relatively small diameter air duct having a diameter of 150 mm or less can be applied to the blower. Therefore, for example, when the blower according to the present invention is used for work in a manhole, when the worker moves up and down in the manhole during work, the movement of the worker is prevented from being hindered by the air duct. it can. Thereby, working efficiency can be improved.

  Preferably, the electric fan is a propeller axial fan. The propeller axial fan can generate a larger air volume than a centrifugal blower.

  Preferably, a cigar socket adapter that can be inserted into a cigar socket of an automobile is further provided, and electric power can be taken out from the cigar socket of the automobile. According to this configuration, the blower can be driven using the cigar socket of the automobile as a power source. Thereby, it becomes possible to use a blower without using a separate generator at a site where it is difficult to obtain power for driving from a commercial power source.

  Preferably, the housing is further provided with an air inlet cover that covers the air inlet from the outside, and the air inlet cover is opened downward. According to this configuration, for example, when the blower according to the present invention is used for outdoor work in rainy weather, the air intake cover can prevent rainwater from entering the housing from the air intake. . That is, it is possible to prevent the electric fan from being damaged by rainwater. Therefore, the blower according to the present invention can be advantageously applied to work outdoors in rainy weather.

  Preferably, the total weight of the blower is 20 kg or less. According to this configuration, since the blower can be carried by one person, the convenience of carrying the blower can be improved when the blower is installed or moved on the site.

  According to the present invention, when an electric fan having a diameter of 150 mm or less, in which a pressure loss is relatively large, is applied to a blower by selecting an electric fan having an air blowing capacity that brings about the wind pressure and air volume as described above, A sufficient air volume can be blown into the work site. That is, a relatively small diameter air duct having a diameter of 150 mm or less can be applied to the blower. Therefore, for example, when the blower according to the present invention is used for work in a manhole, it is possible to prevent the movement of the worker from being hindered by the air duct when the worker moves up and down in the manhole during work. it can. Thereby, working efficiency can be improved.

It is the schematic which shows the use condition of the air blower concerning one Embodiment of this invention. It is a left view of the air blower concerning one embodiment of the present invention. It is the left view which looked at the state which removed the ventilation duct from the air blower shown in FIG. 2 from the left side. It is the front view which looked at the air blower of the state shown in FIG. 3 from the arrow IV in FIG. FIG. 5 is a side cross-sectional view of the blower shown in FIG. 4 taken along VV in FIG. 4 and viewed from the left side. It is a graph which illustrates the air volume-static pressure characteristic of a standard electric fan.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the structure of the air blower 11 which concerns on one Embodiment of this invention is demonstrated using FIGS. In the following description, the front-rear and left-right directions are based on FIG. 2, the front side indicates the left side of the paper in FIG. 2, and the left side indicates the front side of the paper in FIG.

  With reference to FIGS. 1-5, when the air blower 11 which concerns on this invention needs to work in the space closed from external air like the work site 102 provided in the inside of the manhole 101, for example, It is a blower used to send outside air into the work site 102.

  The blower 11 has a box-shaped housing 12, an electric fan 13 attached to the inside of the housing 12, one end detachably connected to the housing 12 via a duct attachment adapter 14, and the other end at the work site 102. And a tubular air duct 15 disposed therein.

  The housing 12 includes a bottom wall portion 16, a left side wall portion 17 rising from the left end of the bottom wall portion 16, a right side wall portion 18 rising from the right end of the bottom wall portion 16, and a front wall portion rising from the front end of the bottom wall portion 16. 19, a rear wall portion 20 that rises from the rear end of the bottom wall portion 16, and front and rear wall portions 19 and 20 and upper ends of the left and right side wall portions 17 and 18, and an internal space S defined by these four wall portions is defined. And a ceiling wall portion 21 that is closed from above.

  The bottom wall portion 16 is a rectangle that is long in the left-right direction, and the front and rear wall portions 19, 20 and the left and right side wall portions 17, 18 rise from the outer edge of the bottom wall portion 16 vertically upward. That is, the housing 12 has a hollow quadrangular prism shape that is long in the left-right direction. Legs 22 are provided at the four corners of the bottom surface of the bottom wall portion 16, and the housing 12 is supported from below so that the housing 12 is disposed horizontally.

  A blower opening 23 that is a circular through hole is provided in the central region of the front wall portion 19. And the cylindrical duct attachment adapter 14 which protrudes toward the front from the front surface of the front wall part 19 is provided so that it may connect with this ventilation port 23. As shown in FIG. More specifically, the duct mounting adapter 14 includes a conical cylinder portion 14a extending while reducing the diameter from the outer edge of the air blowing port 23 toward the front, and a substantially horizontal extension from the front end of the conical cylinder portion 14a toward the front. And the existing cylindrical portion 14b. The air duct 15 is detachably fitted into the cylindrical portion 14b. The air flow discharged from the blower opening 23 by the electric fan 13 flows through the inside of the duct mounting adapter 14 and is sent into the blower duct 15 without leakage. The shapes of the conical cylinder portion 14a and the cylindrical portion 14b are not limited to those shown in the drawings, and are appropriately designed in consideration of the diameter of the air duct 15 used, the flow path resistance against the airflow flowing through the inside, and the like.

An electric fan 13 that generates an airflow for blowing air is attached to the internal space S of the housing 12. The electric fan 13 is attached to the inner surface of the front wall portion 19 so as to cover the air blowing port 23 from the inner space S side. The electric fan 13 according to the present embodiment is a propeller axial fan, and includes an electric motor 13m and a plurality of propellers 13p that are rotationally driven by the electric motor 13m. The electric fan 13 according to the present embodiment has a maximum power consumption of 160 W or less, a maximum static pressure of 550 Pa or more, and a maximum air volume of 10 m ³ / min or more. The reason why the electric fan 13 having such specifications is applied to this embodiment will be described later.

  A power switch 30 is provided at the upper left portion of the front wall portion 19, and a power socket 31 is provided at the lower left portion. The power switch 30 and the power socket 31 are electrically connected to the electric fan 13 in the internal space S. A power cord 32 is connected to the power socket 31, and this power cord 32 is electrically connected to a cigar socket of an automobile via a commercial power outlet or a cigar socket adapter described later.

  In the central region of the rear wall portion 20, there is provided a circular air inlet 24 for taking in outside air toward the internal space S of the housing 12 when the electric fan 13 is driven. The air inlet 24 is provided so as to be substantially coaxial with the air outlet 23 from the viewpoint of smoothing the flow of the airflow generated in the internal space S. In order to prevent foreign matter from entering the internal space S, a fence member covering the air inlet 24 or a dustproof filter (both not shown) may be separately attached.

  An air inlet cover 25 that covers the air inlet 24 from the outside is further provided on the outer side of the rear wall portion 20. The air inlet cover 25 is connected to the left and right cover side wall portions 26 that extend substantially in parallel with the left and right side wall portions 17 and 18 and the left and right cover side wall portions 26, and is rearward and downward from the upper end to the lower end. And a cover rear wall 27 extending toward the front. A cover opening 28 defined by the left and right cover side wall portions 26 and the cover rear wall portion 27 is formed at the lower end of the air inlet cover 25 so as to open downward. That is, when the electric fan 13 is driven, outside air flows from the cover opening 28 and enters the air inlet 24. By providing the air inlet cover 25 in this way, for example, when the blower 11 is used for outdoor work in rainy weather, rainwater can be prevented from entering the internal space S from the air inlet 24. Thereby, it is possible to prevent the electric fan 13 from being damaged by rainwater. In other words, the blower 11 according to the present embodiment can be advantageously applied to work outdoors in the rainy weather. Note that the shape of the air inlet cover 25 is not limited to the illustrated one, and is appropriately designed in consideration of the flow resistance and the like with respect to the airflow flowing inside the cover.

  A handle portion 29 is provided on the top surface of the top wall portion 21. When the blower 11 is carried, the main body can be carried with the handle portion 29.

When the blower 11 is in use, the blower duct 15 is detachably fitted at one end to the cylindrical portion 14 b of the duct attachment adapter 14, and the other end passes through the manhole 101 and is introduced into the work site 102. The air duct 15 is a long bellows-like tubular member, and is excellent in stretchability and flexibility. Here, the blower 11 according to this embodiment, by performing the optimization specifications of the electric fan 13, the diameter phi _d of the air duct 15 made it possible to 150mm or less. This will be described below.

  First, the relationship between the air volume-static pressure characteristic of the electric fan and the flow path resistance characteristic will be described with reference to FIG. FIG. 6 is a graph illustrating the airflow-static pressure characteristics of a standard electric fan. A line 33 in FIG. 6 indicates the air flow-static pressure characteristics of a standard electric fan, and alternate long and short dash lines 34 to 36 indicate flow path resistance characteristics.

Referring to FIG. 6, generally, there is an inversely proportional relationship between the static pressure generated by the electric fan and the air volume, as indicated by line 33. That is, the air volume increases when the static pressure is small, while the air volume decreases when the static pressure increases. When an electric fan is incorporated in an arbitrary device to generate an air flow, flow passage resistance (pressure loss) occurs in the air flow passage generated in the device. Such channel resistance characteristics vary depending on the shape and length of the channel. Lines 34 to 36 in FIG. 6 illustrate three types of typical flow path resistance characteristics. In addition, it has shown that the flow-path resistance of an apparatus is so large that the inclination of the lines 34-36 is large (flow-path resistance: Line 34 <Line 35 <Line 36). The air volume and static pressure of the airflow that actually flows in the apparatus when the electric fan is driven are indicated by the intersection of the air volume-static pressure characteristics and the flow path resistance characteristics of the electric fan shown in FIG. For example, in the case of the apparatus having the flow path resistance characteristic indicated by the line 34, the required static pressure P ₃₇ and the air volume Q ₃₇ flowing through the apparatus at that time are indicated by the intersection point 37 between the line 33 and the line 34. As shown in FIG. 6, when the flow resistance of the apparatus increases to the lines 34, 35, and 36, the air volume decreases to Q ₃₇ , Q ₃₈ , and Q ₃₉ , but is necessary to secure this air volume. It can be seen that the static pressure to be as large as P ₃₇ , P ₃₈ , P ₃₉ .

Here, considering the tubular air duct 15 as described above, since the higher the flow resistance to be reduced in diameter phi _d of the air duct 15 increases, the air volume flowing through the air duct 15 is reduced, and, It can be seen that there is a need for an electric fan that can provide greater static pressure. In general, in a blower for a work site, an air volume of about 10 m ³ / min or more is required as an air volume to be blown from the air duct into the work site. Due to these various factors, it has been conventionally difficult to reduce the diameter of the air duct.

  Therefore, the inventor of the present application pays attention to the airflow-static pressure characteristics of the electric fan and the flow resistance characteristics of the air duct, which vary in association with each other, and even when the diameter of the air duct is set to 150 mm or less, an appropriate airflow is achieved. The blower 11 is configured so as to be able to ensure the above.

  Next, a description will be given of verification results performed by the inventors of the present invention using the electric fan 13 and the air duct 15 having the specifications shown in Table 1 below.

The inventor of the present application calculates the flow resistance of the air duct 15 having a diameter of 125 mm and a length of 5 m, and even when this air duct 15 is used, the air volume of about 10 m ³ / min or more is secured from the air duct opening. The airflow-static pressure characteristics of the fan that can do is discussed. Then, as shown in Table 1, a propeller axial flow fan having a maximum static pressure of 1000 Pa and a maximum air volume-static pressure characteristic of 15.5 m ³ / min was constructed and applied to the blower 11. As a result of the verification under the above conditions, an air volume of about 11 m ³ / min could be secured as the air volume discharged from the opening of the air duct 15.

Thus, according to the present invention, the relationship between the air volume-static pressure characteristics of the electric fan 13 and the flow path resistance characteristics depending on the dimensions of the air duct 15 is taken into consideration, and the electric fan 13 and the air duct 15 By optimizing the specifications, the diameter of the air duct can be made 150 mm or less. Accordingly, as shown in FIG. 1, for example, when the worker A moves up and down in the manhole 101 having a diameter φ _m = 600 mm, the ratio of the diameter φ _{d of the} air duct 15 to the diameter φ _{m of the} manhole 101 Therefore, the movement of the worker A can be prevented from being obstructed by the air duct 15. Therefore, working efficiency can be improved compared with the conventional air blower.

  The electric fan 13 used in the verification has an input power of 140W. Therefore, the blower 11 according to the present invention can take out electric power from the cigar socket of the automobile by using a cigar socket adapter (not shown) that can be inserted into the cigar socket of the automobile. According to this structure, it becomes possible to drive the blower 11 by using the cigar socket of the automobile as a power source. Thereby, it becomes possible to use the blower 11 without using a separate generator at a site where it is difficult to obtain power for driving the blower 11 from a commercial power source. Therefore, the blower 11 can be applied to a wider range of uses. The maximum usable power of the cigar socket of an automobile is about 180W. Therefore, not only the electric fan with the input power of 140 W used for the verification but also the electric fan with the maximum power consumption of 160 W or less can safely use the cigar socket of the automobile as a power source.

  Moreover, since the air blower 11 which concerns on this embodiment uses the electric fan with comparatively low electric power, since a generator etc. are not required separately, it is also possible to suppress a total weight to 20 kg or less. The top wall 21 is provided with a handle 29 for transporting the main body. According to this configuration, since the blower 11 can be carried by one person, the convenience related to the transportation of the blower 11 can be improved when the blower 11 is installed or moved on the site.

In the above embodiment, the maximum air volume of the electric fan is defined such that 10 m 3 ^/ min or more, not limited to this, according to the usage status of the site, for example 7~9m 3 ^/ min about air volume It is good also as a structure which can be adjusted so that it may become.

  Moreover, in the said embodiment, although it verified using the electric fan and ventilation duct of the specification shown in Table 1, it is not limited to this. As described above, the flow resistance determined by the static pressure and air volume of the electric fan, the diameter, length, and shape of the air duct, and the flow resistance in the housing are mutually linked and used. This affects the amount of air discharged from the air duct opening end at the time. Therefore, within the scope of the present invention, these combinations can be appropriately configured so as to be optimal according to the application.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to the thing of embodiment shown in figure. Various modifications and variations can be made to the illustrated embodiment within the same range as the present invention or within an equivalent range.

  The present invention provides a blower capable of improving the working efficiency inside a manhole or the like, and is advantageously applied to a blower used at a construction site or the like.

  DESCRIPTION OF SYMBOLS 11 Blower, 12 Housing | casing, 13 Electric fan, 13m Electric motor, 13p propeller, 14 Duct attachment adapter, 15 Air duct, 16 Bottom wall part, 17 Left side wall part, 18 Right side wall part, 19 Front wall part, 20 Rear wall Part, 21 top wall part, 22 foot part, 23 air outlet, 24 air inlet, 25 air inlet cover, 26 cover side wall part, 27 cover rear wall part, 28 cover opening, 29 handle part, 30 power switch, 31 power socket , 32 Power cord, 33, 34, 35, 36 lines, 37, 38, 39 points, 101 Manhole, 102 Work site.

Claims (5)

A blower used to send outside air into a work site closed from outside air,
A box-shaped housing having an air inlet and an air outlet and having a handle on the upper surface;
An electric fan attached to the air outlet from the inside of the housing;
A tubular air duct having one end detachably connected to the air outlet and the other end disposed in the work site,
The electric fan has a power consumption of 160 W or less, a maximum static pressure of 550 Pa or more, and a maximum air volume of 10 m ³ / min or more,
The air blower has a diameter of 150 mm or less.   The blower according to claim 1, wherein the electric fan is a propeller axial fan.   The blower according to claim 1 or 2, further comprising a cigar socket adapter that can be inserted into a cigar socket of an automobile, wherein electric power can be taken out from the cigar socket of the automobile. The housing is further provided with an air inlet cover that covers the air inlet from the outside,
The blower according to any one of claims 1 to 3, wherein the air inlet cover is open toward a lower side. The blower according to any one of claims 1 to 4, wherein the total weight is 20 kg or less.

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