U.S. patent application number 16/346115 was filed with the patent office on 2019-08-22 for engine blower.
This patent application is currently assigned to Koki Holdings Co., Ltd.. The applicant listed for this patent is Koki Holdings Co., Ltd.. Invention is credited to Naoto ICHIHASHI.
Application Number | 20190257237 16/346115 |
Document ID | / |
Family ID | 62024767 |
Filed Date | 2019-08-22 |
United States Patent
Application |
20190257237 |
Kind Code |
A1 |
ICHIHASHI; Naoto |
August 22, 2019 |
ENGINE BLOWER
Abstract
An engine blower is achieved which can obtain a large blowing
volume and a high cooling efficiency of the cylinder and the
muffler. A suction opening is formed in the second case
partitioning the volute chamber and the muffler chamber at the
front of the partition plate and at the rear of the muffler cover.
The volute chamber has a shape that the width perpendicular to the
front-rear direction is locally narrowed behind the suction
opening, and a first curved portion is provided immediately after
the suction opening, and a first curved portion is provided in the
second case. Immediately before the first curved portion, the air
pressure locally drops due to the air supply flow whose flow
velocity is increased. The air pressure becomes a negative pressure
state when viewed from the muffler chamber. Air flows from the
muffler chamber side to the volute chamber side via the suction
opening.
Inventors: |
ICHIHASHI; Naoto; (Ibaraki,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Koki Holdings Co., Ltd. |
Tokyo |
|
JP |
|
|
Assignee: |
Koki Holdings Co., Ltd.
Tokyo
JP
|
Family ID: |
62024767 |
Appl. No.: |
16/346115 |
Filed: |
October 6, 2017 |
PCT Filed: |
October 6, 2017 |
PCT NO: |
PCT/JP2017/036474 |
371 Date: |
April 30, 2019 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F04D 25/084 20130101;
F04D 29/58 20130101; F04D 25/166 20130101; F04D 29/584 20130101;
F04D 29/663 20130101; F04D 25/02 20130101; F04D 29/4226 20130101;
F01P 2001/023 20130101; F04D 29/44 20130101; F01P 5/06 20130101;
F01P 1/02 20130101; F01P 1/06 20130101; F04D 29/5806 20130101 |
International
Class: |
F01P 1/06 20060101
F01P001/06; F01P 5/06 20060101 F01P005/06; F01P 1/02 20060101
F01P001/02 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 31, 2016 |
JP |
2016-213429 |
Claims
1. An engine blower comprising: an engine serving as a power
source; a muffler mounted to a cylinder of the engine and in front
of the cylinder for causing exhaust gas from the cylinder to pass
and discharge; a muffler cover covering the muffler and forming a
muffler chamber in which accommodate the muffler; a blower fan for
generating a blown air flow emitted forward in a volute chamber by
rotation of a drive shaft of the engine; a cooling fan for
generating a cooling air for cooling the cylinder by the rotation
of the drive shaft; a negative pressure generating device provided
in the volute chamber for generating a negative pressure by a flow
of the blown air; a partition wall for partitioning the muffler
chamber and a cylinder chamber that accommodates the cylinder; and
a suction opening communicating the muffler chamber and the
cylinder chamber in front of the partition wall and causing air
flow from a side of the muffler chamber to a side of the cylinder
chamber to pass by the negative pressure.
2. The engine blower according to claim 1, further comprising a
case covering the blower fan and constituting the volute chamber,
wherein the negative pressure generating means is a first curved
portion curved in the case so that the width of the air path along
the front-rear direction of the case becomes wider toward the
front, and the suction opening is located in front of the first
curved portion.
3. The engine blower according to claim 2, a second curved portion
having curved shape such that the width of the air path widens
rearward is provided behind the first curved portion in the
case.
4. The engine blower according to claim 2, the blower fan is a
centrifugal fan that generates the blown air from the rotational
axis side in the volute chamber.
5. The engine blower according to claim 4, the first curved portion
is located an outside the blower fan when viewed from the rotation
axis.
6. The engine blower according to claim 4, wherein the suction
opening is located an outside the blower fan when viewed from the
rotation axis.
7. The engine blower according to claim 4, wherein the blown air
flow is emitted forward from a cylindrical nozzle whose inside
communicates with the volute chamber, and the suction opening is
located closer to the center of the rotation axis than the center
axis of the cylindrical nozzle.
8. The engine blower according to claim 1, wherein a front surface
of the muffler cover is provided with an opening for passing
cooling air flows through the suction opening toward the muffler
chamber side to cool the muffler.
9. The engine blower according to claim 3, the blower fan is a
centrifugal fan that generates the blown air from the rotational
axis side in the volute chamber.
10. The engine blower according to claim 9, the first curved
portion is located an outside the blower fan when viewed from the
rotation axis.
11. The engine blower according to claim 10, wherein the suction
opening is located an outside the blower fan when viewed from the
rotation axis.
12. The engine blower according to claim 10, wherein the blown air
flow is emitted forward from a cylindrical nozzle whose inside
communicates with the volute chamber, and the suction opening is
located closer to the center of the rotation axis than the center
axis of the cylindrical nozzle.
13. The engine blower according to claim 11, wherein the blown air
flow is emitted forward from a cylindrical nozzle whose inside
communicates with the volute chamber, and the suction opening is
located closer to the center of the rotation axis than the center
axis of the cylindrical nozzle.
14. The engine blower according to claim 2, wherein a front surface
of the muffler cover is provided with an opening for passing
cooling air flows through the suction opening toward the muffler
chamber side to cool the muffler.
15. The engine blower according to claim 3, wherein a front surface
of the muffler cover is provided with an opening for passing
cooling air flows through the suction opening toward the muffler
chamber side to cool the muffler.
Description
BACKGROUND
Technical Field
[0001] The present invention relates to a structure of an engine
blower powered by an engine.
Description of Related Art
[0002] Among the blowers for generating and blowing wind, an engine
blower in which an engine is used as a power source is effective
because the wind power can be particularly increased. In
particular, when a small engine is used, the engine blower can be
portable, and the operator can hold the engine blower and blow the
air to a desired location. As a result, for example, dust on the
road surface can be removed.
[0003] The configuration of such an engine blower is described in,
for example, Patent Document 1. In this engine blower, a small
air-cooled engine is used as a power source. The drive shaft of the
engine is fixed with a blower fan for generating air emitted from
the nozzles and a cooling fan for generating cooling air for
cooling the engine itself. The air flow generated by the fan is
emitted from its tip via an elongate nozzle. On the other hand, the
cooling air generated by the cooling fan cools the cylinder and the
muffler of the engine, and then is discharged to the outside. By
directing the nozzle to a desired location, the operator can blow
an air supply flow emitted from the tip thereof.
PRIOR ART DOCUMENT
Patent Document
[0004] Patent document 1: Japan Patent Laid-Open No.
JP-A-2010-13937
SUMMARY
Problem to be Solved by the Invention
[0005] As described above, in the blower in which the blower fan
and the cooling fan are used together, the blower fan is larger in
size, and by making the blower fan large in size, it is possible to
increase the amount of blown air emitted from the nozzles. However,
when the blower fan is large in size, it is difficult to increase
the cooling efficiency of the cylinder and the muffler because it
is difficult to increase the size of the cooling fan.
[0006] Further, it is also possible to cool the cylinder or the
muffler by using a part of the air supply flow generated by the air
supply fan. However, in this case, the blowing amount of the
blowing air flow emitted from the nozzle is lowered. Further, it is
the cylinder and the muffler that are cooled by the cooling air,
and in order to cool them together, the path of the cooling air
becomes complicated, and it is difficult to efficiently cool both
of them.
[0007] That is, a blower which can obtain a large blowing amount
and a high cooling efficiency of the cylinder and the muffler is
desired.
[0008] The present invention has been made in view of the above
problems, and an object thereof is to provide an invention which
solves the above problems.
[0009] In order to solve the above-mentioned problems, the present
invention has the following configurations. The engine blower of
the present invention comprises: an engine serving as a power
source; a muffler mounted on the cylinder in front of the cylinder
of the engine for discharging exhaust gas from the cylinder; a
muffler cover covering the muffler and forming a muffler chamber in
which the muffler is accommodated; a blower fan for generating a
blown air flow emitted forward in a volute chamber by rotation of a
drive shaft of the engine; a cooling fan for generating a cooling
air for cooling the cylinder by rotation of the drive shaft;
negative pressure generating means provided in the volute chamber
for generating a negative pressure by the flow of the blown air
flow; a partition wall for partitioning between the cylinder
chamber in which the cylinder is accommodated; and an opening for
passing the muffler chamber and the volume chamber forward of the
partition wall for passing an air flow from the volume chamber to
the volume chamber by suction side. The engine blower of the
present invention includes a case that covers the blower fan and
constitutes the volute chamber, and the negative pressure
generating means is a first curved portion that is curved in the
case so that the width of the air path along the front-rear
direction of the case becomes wider toward the front, and the
suction opening is located in front of the first curved portion.
The engine blower of the present invention is characterized in that
a second curved portion having a curved shape is provided behind
the first curved portion in the case so that the width of the air
path becomes wider toward the rear. In the engine blower of the
present invention, the blower fan is a centrifugal fan that flows
the blower flow from the rotational axis side in the volute
chamber. In the engine blower of the present invention, the first
curved portion is located outside the blower fan when viewed from
the rotation axis. In the engine blower of the present invention,
the suction opening is located outside the blower fan when viewed
from the rotation axis. In the engine blower of the present
invention, the air supply flow is configured to be emitted forward
from a cylindrical nozzle whose inside communicates with the volute
chamber, and the suction opening is located on the side of the
rotation axis side of the center axis of the nozzle. In the engine
blower of the present invention, an opening for cooling the muffler
and allowing cooling air flowing through the suction opening to
pass toward the muffler chamber side is provided in the front
surface of the muffler cover.
Effect of the Invention
[0010] Since the present invention is configured as described
above, it is possible to obtain a blower which can obtain a large
blowing amount and a high cooling efficiency of the cylinder and
the muffler.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a side view of an engine blower according to an
embodiment of the present invention.
[0012] FIG. 2 is a cross-sectional view in the direction A-A in the
engine blower according to the embodiment of the present
invention.
[0013] FIG. 3 is a side view of the engine blower according to the
embodiment of the present invention in a state in which the first
case and the fan cover are removed;
[0014] FIG. 4 is a cross-sectional view in the B-B direction in the
engine blower according to the embodiment of the present
invention.
[0015] FIG. 5 is a cross-sectional view in the C-C direction in the
engine blower according to the embodiment of the present
invention.
[0016] FIG. 6 is a diagram showing a flow of air between a volute
chamber and a muffler chamber in an engine blower according to an
embodiment of the present invention.
DESCRIPTION OF THE EMBODIMENTS
[0017] The structure of an engine blower according to an embodiment
of the present invention will be described. In this engine blower,
an engine (air-cooled engine) is used as a power source. As the
drive shaft (crankshaft) of the engine rotates, an air flow emitted
from the nozzle with a large air flow rate and cooling air for
cooling the cylinders of the engine are generated. The cooling air
is also used to cool the muffler, but in addition, an air flow
generated by a negative pressure generated when the feed air flow
flows in the volute chamber is also used to cool the muffler. At
this time, since it is suppressed that the flow rate of the air
supply flow decreases in order to cool the muffler, the air supply
amount of the air supply flow can be increased, and the cooling
efficiency of the cylinder and the muffler can also be
increased.
[0018] FIG. 1 is a side view of this blower (engine blower) 1, and
FIG. 2 is a cross-sectional view in the direction A-A thereof. When
the blower 1 is actually used, the operator grasps the handle 11
provided at the upper portion in FIG. 1, and is positioned on the
left side of the blower 1, that is, on the front side of the
drawing in FIG. 1. The air flow is emitted toward the left side
(front) from a nozzle (not shown) mounted via a nozzle mounting
portion 45 on the left side (front) in FIG. 1. The strength or
ON/OFF of the air supply flow is controlled by operating a trigger
lever 13 provided at the lower portion of the handle 11. In FIG. 1,
a side view along the drive axis of the engine used is shown from
the left as seen from the operator side.
[0019] In FIG. 2, a cross section along the drive shaft 21 of the
engine 20 used here and a cross section perpendicular to the intake
and exhaust directions thereof are shown, and this cross section is
seen from the rear side. In the engine 20, a cylinder 24 in which a
piston 23 for driving the drive shaft 21 slides in the vertical
direction is provided in an upper portion of a crankcase 22 in
which the drive shaft 21 is accommodated. The engine 20 is an
air-cooled type, and a plurality of plate-like cooling fins 24 A
extending in the horizontal direction are formed around the
cylinder 24 side by side in the vertical direction, and cooling air
mainly flows between the cooling fins 24 A to cool the cylinder 24
which generates heat during operation.
[0020] A starting device 25 is mounted on the right side of the
drive shaft 21, and by forcibly rotating the drive shaft 21 by the
starting device 25, fuel supplied from a fuel tank 26 provided on
the lower side of the crankcase 22 is guided to the engine 20 side,
and the engine 20 can be started. When the drive shaft 21 rotates,
electric power generated by a power generating coil (not shown) is
supplied to an ignition plug (not shown in FIG. 2) mounted on the
cylinder 24 via the ignition device 27.
[0021] On the left side of the drive shaft 21, a cooling fan 31 and
a blower fan 32 having a diameter larger than that of the cooling
fan 31 are successively fixed from the side close to the crankcase
22. In FIG. 2, a first case (case) 41, a second case (case) 42, and
a third case (case) 43 made of resin are combined to form a
cylinder chamber 40 A, which is a space in which the cylinder 24
and the cooling fan 31 are built, and a volute chamber 40 B, which
is a space in which the blower fan 32 is built, respectively. The
cooling air CA generated by the cooling fan 31 flows through the
cylinder chamber 40 A as indicated by arrows in FIG. 2, thereby
cooling the cylinder 24.
[0022] The blower fan 32 is covered with a fan cover 44 from the
left side, and a large number of openings 44 A are formed in the
fan cover 44. The blower fan 32 is a centrifugal fan that generates
a blowing air flow by flowing outside air sucked from the opening
44 A along the outer circumferential direction from the side of the
rotation axis, i.e., the axis of the drive shaft 21. This air
supply flow flows through the volute chamber 40 B.
[0023] FIG. 3 shows a configuration in which the first case 41 and
the fan cover 44 are removed in the configuration of FIG. 1, and
shows the flow of the air supply flow W in the volute chamber 40 B.
Here, it is assumed that the blower fan 32 is driven to rotate
counterclockwise. In FIG. 1, a nozzle mounting portion 45 is formed
by combining a first case 41 and a second case 42, and a long
cylindrical nozzle (not shown) is mounted on the nozzle mounting
portion 45. The central axis of the nozzle and nozzle mounting
portion 45 is shown as X in FIG. 3. In FIG. 3, the air supply flow
W flows counterclockwise in the volute chamber 40 B, and then is
emitted forward from the nozzle through the nozzle mounting portion
45.
[0024] FIG. 4 is a cross-sectional view taken along the B-B
direction in FIGS. 1 and 3, and shows a case in which the first
case 41 and the fan cover 44 are also mounted. In this figure, a
structure is shown in which a cross section of the engine 20 along
the intake/exhaust direction is viewed from the upper side. FIG. 5
is a cross-sectional view taken along the C-C direction in FIG. 4,
and here, a structure in which a cross-section taken along the
intake/exhaust direction is viewed from the right side is shown. In
FIGS. 4 and 5, a carburetor 51 is connected to the rear of the
cylinder 24 via an intake pipe 28, and an air cleaner 52 is
connected to the rear of the carburetor 51. In the carburetor 51,
an air-fuel mixture is formed by the air introduced through the air
cleaner 52 and the fuel supplied from the fuel tank 26, and is
supplied to the engine 20 (crankcase 22) through the intake port 24
B on the cylinder 24 side. In the cylinder 24, the air-fuel mixture
is compressed and ignited by an upper spark plug 29, thereby
operating the engine 20.
[0025] On the other hand, a muffler 53 for passing exhaust gas
discharged from the exhaust port 24 C on the cylinder 24 side at
this time is connected to the front of the cylinder 24. The exhaust
gas passes through the catalyst inside the muffler 53 and is then
discharged toward the outside air. By the catalytic reaction at
this time, the muffler 53 also generates heat in the same manner as
the cylinder 24 during the operation. The muffler 53 is covered
with a resin muffler cover 46 from the front. Between the cylinder
24 and the muffler 53, a plate-like partition plate 54 extending
perpendicularly to the plane of the drawing in FIGS. 4 and 5 is
provided. The muffler cover 46 is combined with or integrated with
the second case 42, the third case 43, and the like, and a
partition plate 54 is further provided to form a muffler chamber 40
C in which the muffler 53 is accommodated. However, the partition
plate 54 does not exist on the right side (left side in FIG. 4) of
the cylinder 24 and the muffler 53, and this portion becomes the
communication passage 40 D that connects the cylinder chamber 40 A
and the muffler chamber 40 C, and the cooling air CA can flow from
the cylinder chamber 40 A to the muffler chamber 40 C through this
communication passage 40 D. A plurality of small openings 46 A is
provided in front of the muffler cover 46, and the muffler chamber
40 C communicates with the front outside air through the openings
46 A.
[0026] FIG. 6 is a diagram showing the flow of air during operation
in FIG. 4. The cooling air CA shown in FIG. 2 is roughly divided
into a cooling air CA1 flowing behind the cylinder 24 and a cooling
air CA2 flowing in front of the cylinder 24 in a top view as shown
in FIG. 6. The cooling air CA1 and the cooling air CA2 both pass
through the communication passage 40 D and are discharged forward.
At this time, the right side surface of the muffler 53 is cooled by
these. However, in the muffler 53, the cooling air CA1 and the
cooling air CA2 are in contact only with the right side surface
thereof, and in this condition, the cooling air CA1 and the cooling
air CA2 after the cylinder 24 is cooled and the temperatures are
raised are in contact with the muffler 53, so that the cooling air
CA1 and the cooling efficiency of the muffler 53 by the CA2 are not
high.
[0027] In FIG. 6, the air supply flow W generated by the blower fan
32 flows in the volute chamber 40 B from the rear toward the front,
and the flow rate thereof is larger than the cooling air CA1 and
the cooling air CA2, as described above. Since the second case 42
exists between the volute chamber 40 B and the adjoining cylinder
chamber 40 A and the muffler chamber 40 C, and the cylinder chamber
40 A and the volute chamber 40 B are partitioned by the second case
42, the air supply flow W, the cooling air CA1, and the cooling air
CA2 do not flow between the cylinder chamber 40 A and the volute
chamber 40 B.
[0028] On the other hand, in the second case 42 that partitions the
volute chamber 40 B and the muffler chamber 40 C, an opening
(suction opening 42 A) is formed in the front of the partition
plate 54 and in the rear of the muffler cover 46. Therefore, there
may be a flow of air between the volute chamber 40 B and the
muffler chamber 40 C through the suction opening 42 A.
[0029] Here, as shown in FIGS. 4 and 6, the volute chamber 40 B has
a shape such that a width (air path width) perpendicular to the
front-rear direction is locally narrowed behind the suction opening
42 A (upstream side in the flow direction of the air supply flow
W). Specifically, immediately after the suction opening 42 A, a
portion (first curved portion 41 B) that curves rightward (leftward
in the figure) from the front to the rear in the first case 41 is
provided, and a portion (first curved portion 42 B) that curves
leftward (rightward in the figure) from the front to the rear in
the second case 42. In addition, a portion (second curved portion
41 C) that curves leftward from the front to the rear is provided
at the rear of the first curved portion 41 B in the first case 41,
and a portion (second curved portion 42 C) that curves rightward
from the front to the rear is provided at the rear of the first
curved portion 42 B in the second case 42. By providing the first
curved portions 41 B, 42 B and the second curved portions 41 C, 42
C, the air flow path of the air flow W is locally narrowed between
the first curved portions 41 B, 42 B and the second curved portions
41 C, 42 C, and the flow velocity of the air flow W is locally
increased in this portion. Further, in the second case 42, since
the suction opening 42 A is located forward of the first curved
portion 41 B and on the downstream side in the flow direction of
the air supply flow W, the air supply flow W whose flow speed is
increased and the suction opening 42 A are separated from each
other, and the inflow of the air supply flow W into the muffler
chamber 40 C through the suction opening 42 is suppressed.
[0030] However, the air pressure locally decreases immediately
before the first curved portion 42 B (immediately after the flow of
the air flow W) due to the air flow W whose flow velocity is
increased, and the air pressure becomes a negative pressure state
when viewed from the muffler chamber 40 C. Therefore, air flows
from the muffler chamber 40 C side to the volute chamber 40 B side
via the suction opening 42 A. This air is supplied mainly through
an opening 46 A in front of the muffler cover 46. Therefore, the
cooling air CA3 shown in FIG. 6 flows through the suction opening
42 A. Since this cooled air CA3 is generated from the outside air
through the front opening 46 A, the temperature in contact with the
muffler 53 in the muffler chamber 40 C is room temperature. If a
plurality of the openings 46 A is formed in a wide range on the
front surface of the muffler cover 46, the cooling air CA3 can flow
in a wide range in the left and right directions of the muffler 53.
Therefore, the efficiency of cooling the muffler 53 by the cooling
air CA3 can be increased. At this time, as described above, the
cooling air CA1 and CA2 flowed forward at the right end portion of
the muffler chamber 40 C, while the cooling air CA3 flowed rearward
through the muffler cover 46 (opening 46 A).
[0031] Further, the muffler cover 46 is also cooled by the cooling
air CA3. Therefore, it is possible to use a material having low
heat resistance as a material constituting the muffler cover
46.
[0032] The cooling air CA3 is generated by the negative pressure
generated in the volute chamber 40 B, and after flowing into the
volute chamber 40 B, the cooling air joins the air supply flow W
and is finally emitted forward from the nozzles. Therefore, the
flow rate of the air supply flow W is not impaired by the
generation of the cool air CA3. In addition, although the
temperature of the cooling air CA3 after cooling the muffler 53
rises, the flow rate of the air supply flow W generated by the
blower fan 32 is large, so that the temperature rise of the air
supply flow W finally emitted from the nozzles is slight. For this
reason, in the blower 1, a large amount of blown air flow W is
obtained, and high cooling efficiency of the cylinder 24 and the
muffler 53 is obtained.
[0033] Here, in FIG. 3, the positional relationship among the
suction opening 42 A, the first curved portion 42 B, the second
curved portion 42 C, and the blower fan 32 is shown. As described
above, the blower fan 32 is a centrifugal fan, so that the
generated air flow W flows counterclockwise in FIG. 3 and then
forward along the upper surface of the volute chamber 40 B along
the front and backward direction. It is preferable to generate a
large negative pressure in the volute chamber 40 B at a location of
the suction opening 42 A. Therefore, it is preferable to provide
the suction opening 42 A at a position where the flow velocity of
the air supply flow W is highest in this configuration, and it is
preferable to form the suction opening 42 A outside the blower fan
32 as viewed from the rotation axis side of the blower fan 32 (the
axis of the drive shaft 21) in FIG. 3. However, the flow velocity
of the air supply flow W decreases as it approaches the upper
surface of the volute chamber 40 B with a large distance from the
rotation axis. Therefore, it is preferable to provide the suction
opening 42 A below the center axis X of the nozzle in FIG. 3.
[0034] In order to increase the effect of forming the negative
pressure, it is preferable to provide the first curved portion 42 B
41 B at a place where the flow velocity of the air supply flow W is
high. Therefore, it is preferable that the first curved portion 42
B 41 B is also formed outside the blower fan 32.
[0035] By providing the second curved portion 42 C (41 C) together
with the first curved portion 42 B (41 B), it is possible to form a
region in which the flow velocity of the air supply flow W is
locally increased in the front-rear direction. However, when the
flow velocity of the air supply flow W generated by the blower fan
32 is high, a negative pressure is generated at a point where the
width perpendicular to the flow direction rapidly widens.
Therefore, in such a case, the negative pressure can be generated
downstream of the first curved portion by providing only the first
curved portion without forming the second curved portion on the
upstream side with respect to the flow.
[0036] In the above example, the first curved portions 42 B, 41 B
and the second curved portions 42 C, 41 C are used as negative
pressure generating means for generating a negative pressure by the
flow of the air supply flow W in the volute chamber 40 B. However,
other configurations in the first case, the second case, or other
components separate therefrom may be used to generate the negative
pressure as well. Even in such a case, by providing the suction
opening at a position where the negative pressure is generated,
that is, a position immediately after the position where the
negative pressure generating means is provided in the flow of the
air supply flow, the cooling air can be flowed in the muffler
chamber in the same manner.
REFERENCE SIGNS LIST
[0037] 1 . . . Blower (Engine Blower), 11 . . . Handle, 13 . . .
Trigger (Trigger Lever), 20 . . . Engine, 21 . . . Drive shaft
(Crankshaft), 22 . . . Crankcase, 23 . . . Piston, 24 . . .
Cylinder, 24A . . . Inlet, 24B . . . Inlet, 24C . . . Exhaust, 25 .
. . Starter, 26 . . . Fuel Tank, 27 . . . Igniter, 28 . . . Intake
pipe, 29 . . . Ignition plug, 31 . . . Cooling fan, 32 . . . Blower
fan, 40 A . . . Cylinder, 40B . . . Volute chamber, 40C . . .
Muffler chamber, 40D . . . Communication passage, 41 . . . First
case, 41B, 42B . . . First curved portion, 41C, 42C . . . Second
curved portion, 42 . . . Second case, 42A . . . suction opening, 43
. . . third case, 44 . . . fan cover, 44A, 46A . . . opening, 45 .
. . nozzle mounting portion, 46 . . . muffler cover, 51 . . .
carburetor, 52 . . . air cleaner, 53 . . . muffler, 54 . . .
partition plate, CA, CA1, CA, CA2, and CA3 . . . cooling air, W . .
. air supply flow, X . . . center shaft
* * * * *