JPH09209753A - Blower with engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily utilize a fan case and a fan made of plastic by enhancing engine cooling efficiency by positively blowing air to not only the areas of a cylinder and a cylinder head but also around a flywheel magnet with a simple structure. SOLUTION: A rotor room 56 surrounding a flywheel magnet 22 is formed between a fan case 52 and an engine 10, air is introduced from a positive pressure area 55 in the fan case 52 into the rotor room 56, and the air is one time led into the fan case 52 through the flywheel magnet outer peripheral gap A. The air is further caused to flow out of the opening 61 of the fan case 52 toward the cylinder and the cylinder head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine blower, and more particularly to an engine cooling mechanism for an engine blower.

[0002]

2. Description of the Related Art A blower with an engine is used not only as a blower but also as various working machines such as a power duster such as a medicine sprayer and a backpack type power duster by attaching an attachment. This type of blower with an engine generally has a recoil starter attached to one protruding end of an engine crankshaft, a flywheel magneto attached to an opposite protruding end, and a blower arranged on the flywheel magneto side of the engine. Is adopted.

In such a case, a centrifugal blower directly connected to the engine is generally used. The fan of the blower is directly connected to the crankshaft via the flywheel magneto, and the fan case is directly or indirectly connected to the crankcase of the engine. Is fixed. As a means for cooling the engine, a system utilizing an airflow flowing into a blower is generally employed. References showing a conventional example of such a blower with an engine include, for example, Japanese Utility Model Laid-Open No. 53-1357.
No. 4 and Japanese Utility Model Publication No. 6-18041.

[0004]

However, in this type of conventional blower with an engine, the air taken in from the air intake port at the center of the fan on the side opposite to the engine is pressurized by the fan and the duct on the outer peripheral portion is pressurized. The engine is cooled by providing an opening at a position corresponding to the cylinder or cylinder head of the duct, and allowing part of the air from the blower to flow toward the cylinder or cylinder head of the engine. Is going. According to such a configuration, although the cylinder and the cylinder head can be sufficiently cooled, the cooling near the center of the crankcase, particularly, in a portion where the fan and the engine are enclosed, tends to be insufficient.

[0005] In this case, the engine may be cooled by heat conduction from the mounting surface of the engine and the blower, but a plastic fan or a fan case having a low thermal conductivity and difficult to cool the engine from the mounting surface is required. When used, inconvenience is likely to occur. Incidentally, a device that takes in the air of the blower from between the blower and the engine has been proposed in, for example, Japanese Patent Application Laid-Open No. 54-7034. However, this does not allow the air inlet of the blower to be sufficiently widened.
The blower is inconvenient in that it is difficult to be compact and the structure is complicated, and is not yet general.

SUMMARY OF THE INVENTION The present invention has been made in view of such a conventional technique, and an object of the present invention is to provide cooling with a simple structure by positively applying air around the flywheel magnet together with the cylinder and cylinder head area. To improve
An object of the present invention is to provide a blower with an engine that can easily realize weight reduction and cost reduction by plasticizing a fan or a fan case.

[0007]

A blower with an engine according to a first aspect of the present invention forms a rotor chamber surrounding a flywheel magnet between a fan case of a blower and an engine, and a positive pressure near the outer periphery of the fan case. The above object is achieved by forming an air inlet from the region to the rotor chamber and cooling the engine by the air introduced from the inside of the fan case through the air inlet into the rotor chamber.

According to a second aspect of the present invention, in addition to the structure of the first aspect, the blower with an engine causes a part of the air in the fan case to flow out to a positive pressure region near the outer periphery of the fan case toward the cylinder or the cylinder head. By providing the first opening and forming the air intake at a position on the side opposite to the cylinder with respect to the center of the crankshaft, the above object can be achieved more efficiently.

A blower with an engine according to a third aspect is the blower with an engine according to the first or second aspect, wherein a second opening is formed at a position corresponding to the cylinder on the engine side of the fan case, and air introduced into the rotor chamber is introduced. By introducing the air to the rear surface of the fan in the fan case through a third opening formed in the outer periphery of the flywheel magnet or in the vicinity thereof, and further allowing the air to flow out toward the cylinder or the cylinder head through the second opening. In order to achieve the above object, the periphery of the flywheel magneto is more positively cooled. According to this configuration, the cooling air can be sucked from the rotor chamber to the fan back surface by the rotation of the fan back wall, which is more effective.

According to the blower with an engine of claim 4, in addition to the structure of claims 1 to 3, a fourth opening is formed at a position near the cylinder of the outer peripheral wall of the rotor chamber, and the air introduced into the rotor chamber is introduced. Is configured to flow out from the fourth opening toward the cylinder or the cylinder head, thereby increasing the amount of air that traverses the rotor chamber and achieving the above object more efficiently.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of one embodiment of a blower with an engine to which the present invention is applied. In FIG. 1, the blower with an engine is configured by directly connecting a fan 51 of a blower 50 to a crankshaft 11 of an engine 10 and fixing a fan case 52 of the blower 50 to a case portion (crankcase 12) of the engine 10. There is.

The crankshaft 11 is rotatably supported by left and right bearings 13 and 14 mounted on a crankcase 12, and one end of a connecting rod 16 is attached to a crankpin 15 fixed to a crankshaft of the crankshaft 11. (Large end) is rotatably connected. A cylinder unit 17 having a structure in which a cylinder and a cylinder head are integrated is connected to the crankcase 12 in a sealed state. A piston 18 is slidably fitted to the inner diameter of the cylinder (part) of the cylinder unit 17. Then, the connecting rod 16
The other end (small end portion) of is rotatably connected to the piston 18 via a piston pin.

A combustion chamber 19 is formed above the cylinder (section) of the cylinder unit 17 between the inner surface of the cylinder head (section) and the top surface of the piston 18. An ignition plug 20 desired for the combustion chamber 19 is attached to the cylinder head. The engine of this embodiment is
The crankshaft 11 extends in the lateral direction, and thus is used as a vertical engine in which the axis of the cylinder extends in the vertical direction.

In FIG. 1, the left and right ends of the crankshaft 11 project from the crankcase 12, and the recoil pulley 21 is attached to the projecting part on the right side (opposite side of the fan 51) in the drawing, and the left side in the drawing (fan 51
The flywheel magneto 22 is attached to the protruding portion on the (side) side.

On the other hand, a cover-shaped recoil starter unit 23 that covers the recoil pulley 21 is attached to the right side of the crankcase 12, and the recoil starter 24 is provided inside the recoil starter unit 23.
Is incorporated. This recoil starter 24
By pulling from the outside, it engages with the recoil pulley 21 to transmit torque, and rotates the crankshaft 11 to start the engine.

FIG. 4 is a front view of the flywheel magnet 22 as viewed from the axial direction of the crankshaft 11. 1 and 4, the flywheel magnet 22 is formed of an adduction permanent magnet having an N pole and an S pole magnetized at a predetermined pitch on the outer peripheral portion. An ignition coil (IG coil) 25 formed by winding a coil around a stator (iron core) having a pair of magnetic poles facing the outer peripheral surface of the flywheel magneto 22 with a predetermined gap is fixed.

In the present embodiment, the fan 51 has a shape structure in which a plurality of blades are arranged in the vicinity of the outer circumference of the disk member at a predetermined pitch, and the fan 51 is installed in the flywheel magneto 22 with the blades on the outside. It is fixed in a coaxial relationship by bolting. An air intake port 53 is formed at a central portion of the fan case 52 on the side opposite to the engine (outside).

FIG. 2 is a rear view of the fan case 52 as seen from the engine side (right side in FIG. 1) along the line 2-2 in FIG. 1 and 2, the fan case 5
The outer peripheral portion of the fan case 52 is provided with a scroll area 55 having a gradually increasing radius to increase the flow passage cross-sectional area. A blower discharge part 54 extending tangentially from the scroll area is formed at a predetermined position. The scroll area 55 forms a positive pressure area that is boosted to the discharge pressure in the blower discharge section 54.

1 and 2, the crankcase 1
A rotor chamber 56 is formed between the left side surface of the fan case 2 and the right side surface (back surface) of the fan case 52 so as to surround the flywheel magneto 22 and the ignition coil (IG coil) 25. In the illustrated example, the rotor chamber 56 is formed in a slightly vertically long rectangle. On the left side of the rotor chamber 56 (the right side of the fan case 52), a concentric central opening 57 that forms a predetermined gap A with the outer periphery of the flywheel magneto 22 is formed.

As shown in the figure, in the upper area of the rotor chamber 56 on the back surface of the fan case 52, that is, in the area corresponding to the cylinder unit 17 (cylinder and cylinder head) of the engine, the cylinder and cylinder head are close to each other. A rib 58 having a protruding partition wall shape is formed in a predetermined arrangement. These ribs 58 form a partition wall for efficiently guiding the air flowing out of the rear surface opening of the fan case 52 to be described later to the region of the cylinder and the cylinder head. In FIG. 1,
The flow of the intake air of the blower 50 and the flow of the cooling air of each part are indicated by arrows.

FIG. 3 is a partial sectional view taken along the line 3-3 in FIG. On the back surface of the fan case 52, an air inlet 59 is formed which communicates with the inside of the fan case from the positive pressure region 55 near the outer periphery to the inside of the rotor chamber 56. In the illustrated example, the air inlet 59 is located at a position biased toward the scroll start side below the rotor chamber 56 and has a positive pressure region 55.
, And a closed space communicating with the lower part of the rotor chamber 56. Since the air in the positive pressure region (scroll region) 55 in the fan case 52 is compressed and the pressure is increased, the pressurized air in the fan case 52 flows through the air intake 59 through the air intake 59 during operation of the engine. It is introduced into the chamber 56. The introduction of air into the rotor chamber 56 can be effectively performed while being assisted by a suction effect due to rotation of the back wall of the fan 51 described later.

In this embodiment, as shown in FIGS. 1 and 2, the air intake 59 is located within the positive pressure area (scroll area) 55 near the outer periphery of the fan case 52.
An opening communicating with the engine (a first position) is located at a position different from the first position, for example, at a position substantially corresponding to the upper cylinder and the cylinder head and in a region partitioned by the rib 58, as shown in the illustrated example. ) 63 are formed.
The first opening 63 is for allowing a part of the air in the positive pressure area in the fan case 52 to flow out to the engine side to cool the cylinder and the cylinder head (the illustrated cylinder unit 17) with the air.

In FIG. 2, the rear wall 64 of the fan case 52 is located at a position corresponding to the rotor chamber 56 and near the central opening 57 (flywheel magnet 22).
An opening (third opening) 60 is formed at a position (in the vicinity of the outer periphery). The third opening 60, together with the peripheral clearance A of the central opening 57, allows the positive pressure air introduced into the rotor chamber 56 to be located in the fan case 52 at a position relatively close to the center of the fan 51 rear surface. It is an opening for introducing into the area of. The introduction of air into the area on the back surface of the fan 51 can be effectively performed while being assisted by suction by the rotation of the fan back surface wall.

In FIGS. 1 and 2, an intermediate position of the rear wall 64 of the fan case 52 closer to the center than the outer diameter of the fan 51 and corresponding to the cylinder unit (cylinder and cylinder head) 17 (the above-mentioned Rib 58
An opening (second opening) 61 is formed in one or a plurality of places in the region surrounded by the circles, and is partitioned by the first opening 63 and the rib 58a. The second opening 61 further introduces the air, which is once guided from the inside of the rotor chamber 56 to the rear surface of the fan 51 in the fan case 52 through the third opening 60 formed in the flywheel magnet outer peripheral gap A or in the vicinity thereof, on the engine side. To cool the area of the cylinder or cylinder head by air. The rib 58a may be omitted as appropriate, or may have a shape other than that shown.

In FIG. 1, in this embodiment, the rotor chamber 5
6 (Rib portion of fan case 52 in the illustrated example)
An opening (fourth opening) 62 is also formed at a position close to the cylinder (position on the upper side in the drawing). This fourth opening 62
The air introduced from the air inlet 59 into the rotor chamber 56 is allowed to flow toward the cylinder unit 17 to positively increase the air passing through the rotor chamber 56 and improve the cooling performance of the engine 10 as a whole. It is for.

According to the above-described embodiment, the flow of the cooling air as shown by the arrow in FIG. 1 is formed by the simple structure of forming the opening in the fan case 52, and the air around the flywheel magnet 22 is formed. In addition to improving cooling performance,
An air blower with an engine can be obtained that can actively guide air also to the area of the cylinder and the cylinder head, thereby efficiently cooling the engine 10.
In the prior art, when the material of the fan case or the fan was changed from metal to plastic, it was difficult to sufficiently increase the cooling efficiency due to a decrease in heat transfer. From improving
It is easy to reduce the cost and weight by making the fan case 52 and the fan 51 plastic.

FIG. 5 is a perspective view illustrating a case where the blower with an engine according to the present invention is used as a backpack type power dusting machine. 5, reference numeral 10 denotes an engine, 50 denotes a blower, 71 denotes a tank for storing dusting agent such as a medicine, 72 denotes a flexible duct such as a bellows tube connected to the blower discharge section 54 of the blower 70 (FIG. 2), 73 is a hose, 74 is a jet head such as a jet nozzle, 75 is a supply tube for supplying the dusting agent in the tank 71 into the air in the blower discharge section 54, 7
Reference numeral 6 denotes a backpack comprising a blower with an engine and a frame member on which necessary accessories are mounted, 77 denotes a backrest provided on the backpack 76, and 78 denotes a cushioning portion for cushioning a human body. . The blower with an engine according to the present invention can be used as a blower (blower) itself, in addition to the above working machine.

[0028]

As is clear from the above description, according to the blower with an engine of claim 1, a rotor chamber surrounding the flywheel magnet is formed between the fan case of the blower and the engine, and the vicinity of the outer periphery of the fan case is formed. Since the air inlet leading from the positive pressure area to the rotor chamber is formed and the engine is cooled by the air guided from the inside of the fan case through the air inlet into the rotor chamber, the configuration is simple.
Blower with engine that can positively guide the air cooled around the flywheel magneto to the area of the cylinder and cylinder head to improve the engine cooling efficiency, and easily realize plasticization of the fan case and fan. Will be provided.

According to the blower with an engine of claim 2,
2. The structure according to claim 1, wherein the positive pressure region near the outer periphery of the fan case is provided with a first opening through which a part of the air in the fan case flows out toward the cylinder or the cylinder head, and the cylinder is opposite to the center of the crankshaft. Since the air intake port is formed at the position on the side of the engine, the cooling air around the flywheel magnet is positively guided to the region of the cylinder and the cylinder head more efficiently with a simple structure to improve the engine cooling efficiency. (EN) Provided is a blower with an engine, which can be improved and can easily realize plasticization of a fan case and a fan.

According to the blower with an engine of claim 3,
In addition to the structure of claim 1 or 2, a second opening is formed at a position corresponding to the engine side cylinder of the fan case, and the air introduced into the rotor chamber is formed in the flywheel magneto outer peripheral gap or in the vicinity thereof. In addition to the above-mentioned effect, the flywheel magneto is also provided around the flywheel magneto because the air is guided to the back surface of the fan in the fan case through the third opening and the air is further discharged toward the cylinder or the cylinder head through the second opening. Can be cooled more efficiently, and since air is guided from the back side of the fan to the cylinder side, centrifugal force due to the rotation of the back side of the fan can act on the air, further cooling air from the rotor chamber to the cylinder side. The effect that it can be easily guided is obtained.

According to the blower with an engine of claim 4,
In addition to the structure of claims 1 to 3, a fourth opening is formed at a position close to the cylinder on the outer peripheral wall of the rotor chamber, and the air introduced into the rotor chamber is directed from the fourth opening toward the cylinder or the cylinder head. In addition to the above effects, the amount of air that traverses the rotor chamber can be increased to improve the cooling performance around the flywheel magnet more efficiently, and the fan and fan case can be made of plastic. The effect that it can be realized more easily is obtained.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of a blower with an engine to which the present invention is applied.

FIG. 2 is a rear view of the blower as viewed from an engine side along a line 2-2 in FIG. 1;

3 is a partial cross-sectional view taken along the line 3-3 in FIG.

FIG. 4 is a front view of a flywheel magneto in FIG. 1;

FIG. 5 is a perspective view illustrating a usage form of the blower with an engine according to the present invention.

[Explanation of symbols]

 10 Engine 11 Crankshaft 12 Crankcase 17 Cylinder and Cylinder Head 18 Piston 19 Combustion Chamber 22 Flywheel Magnet 23 Recoil Starter Unit 25 Ignition Coil 50 Blower 51 Fan 52 Fan Case 53 Air Suction Port 54 Blower Discharge Unit 55 Positive Pressure Area (Scroll Area 56 Rotor chamber 57 Central opening 58 Rib (partition wall) 59 Air intake 60 Third opening 61 Second opening 62 Fourth opening 63 First opening 64 Back wall of fan case A Flywheel Magnet outer circumference Gap

Claims (4)

[Claims] 1. A rotor chamber surrounding a flywheel magneto is formed between a fan case of a blower and an engine,
An air blower with an engine, characterized in that an air inlet is formed from a positive pressure region near the outer periphery of the fan case to the rotor chamber, and the engine is cooled by the air introduced into the rotor chamber from the inside of the fan case through the air inlet. 2. A first opening for letting out a part of the air in the fan case toward the cylinder or the cylinder head is provided in a positive pressure region near the outer periphery of the fan case,
The blower with an engine according to claim 1, wherein the air intake port is formed at a position on the side opposite to the cylinder with respect to the center of the crankshaft. 3. A second opening is formed at a position corresponding to the engine side cylinder of the fan case, and the air introduced into the rotor chamber is once passed through a third opening formed in the flywheel magneto outer peripheral gap or in the vicinity thereof. The blower with an engine according to claim 1 or 2, wherein the air is guided to the rear surface of the fan in the fan case, and the air is further discharged toward the cylinder or the cylinder head through the second opening. 4. A fourth opening is formed at a position close to the cylinder on an outer peripheral wall of the rotor chamber, and air introduced into the rotor chamber is discharged from the fourth opening toward a cylinder or a cylinder head. The blower with an engine according to any one of claims 1 to 3.