JPH09287448A - Member for preventing foreign substance from entering internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily prevent foreign substances from entering a cooling air intake port of an internal combustion engine, as neccessary. SOLUTION: This member comprises a pair of mounting means 27, 27 which is removably mounted on a pair of crank case mounting bosses 29, 29 provided on an internal combustion engine parallel each other, wherein the mounting means 27, 27 can grasp the bosses 29, 29 from both sides thereof by means of elastic deformation, and a main body 31 which preyents foreign substances from being took in from a cooling air intake port 25 without impeding air intake effect by the cooling fan of the internal combustion engine 4 when the protector is mounted on the internal combustion engine 4 by the mounting means 27, 27.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a foreign matter intrusion preventing member for preventing foreign matter from entering the inside of an internal combustion engine through a cooling air suction hole of an air-cooled internal combustion engine.

[0002]

2. Description of the Related Art For example, in an air-cooled internal combustion engine mounted as a power source on various working machines such as a brush cutter, a power blower or a hedge trimmer, a fan case of the internal combustion engine while the working machine is being used. When foreign matter such as a branch of a branch, a mowed grass, or a dead leaf enters through the cooling air suction hole formed in the above, the operation of the cooling fan inside the fan case is hindered.

Therefore, conventionally, in order to prevent the entry of foreign matter as described above, a stationary blade extending across the cooling air suction hole is integrally formed in the fan case, or the foreign matter is produced by using a resin. There has been used means such as fitting a grid-like component for prevention into the portion of the cooling air suction hole by utilizing its elastic deformation (for example, actual flat opening 5-924).
24).

[0004]

However, in the above-mentioned conventional techniques, there are disadvantages that it is difficult to process the stationary vanes and the grid-shaped parts, and the parts cannot be easily attached and detached.

The present invention has been made in view of the above circumstances, and a foreign matter intrusion preventing member for an internal combustion engine, which can easily prevent foreign matter from entering through a cooling air suction hole of the internal combustion engine as needed. Is to provide.

[0006]

In order to solve the above-mentioned problems, the foreign matter intrusion preventing member according to the present invention has a mounting means which is detachably attached to a part of the outer surface of an internal combustion engine by elastic deformation, and by the mounting means. A main body for preventing foreign matter from entering the internal combustion engine through a cooling air intake hole without obstructing an intake action by a cooling fan of the internal combustion engine when attached to the internal combustion engine Is.

The mounting means may be attached to the pair of crankcase assembly bosses by elastic deformation that acts so as to sandwich a pair of parallel crankcase assembly bosses adjacent to each other of the internal combustion engine from both sides thereof. Be removable.

Further, when the structure is provided with the position deviation preventing means which is formed on the main body part and abuts against a part of the internal combustion engine to prevent the position deviation of the main body part, after the attachment, the main body part is attached. Even if an unexpected external force acts on the portion, the mounting means is not detached from the crankcase assembly boss portion, which is preferable.

[0009]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 6 is an overall schematic view showing a brush cutter as an example of a working machine equipped with an internal combustion engine using the foreign matter intrusion preventing member according to the present invention.

The brush cutter is provided with a rotary blade 2 made of a metal blade (or a nylon cord or the like) at the tip of the operating rod 1, and a power generating section 3 at the rear end of the operating rod 1. The power generator 3 includes a small air-cooled two-cycle gasoline engine 4 for driving the rotary blade 2 and the engine 4
And a fuel tank 5 for storing the fuel of the engine 4 provided below.

The driving force of the engine 4 is the operating force of the operating rod 1.
It is transmitted to the rotary blade 2 via a transmission shaft (not shown) rotatably supported inside. And the worker
The power generation unit 3 side of the engine 4 is lowered from the shoulder with a suspension band (not shown), and the grips 7 at the left and right ends of the U-shaped handle 6 attached to the operating rod 1 are gripped and attached to the handle 6. The throttle blade 8 is operated to swing the rotary blade 2 vertically and horizontally to perform mowing work.

As shown in FIG. 5, the engine 4 comprises a crankshaft 12 connected to a piston 10 sliding in a cylinder 9 via a connecting rod 11, and the crankshaft 12 is provided.
Is rotatably supported by the crankcase 13 and has a structure known per se.

The crankcase 13 is formed by a recoil starter-side casing 14 and a cooling fan-side casing 15, and these casings 14 and 15 are joined to each other so that the crank chamber 1 is provided between them.
6 are formed. Inside the crank chamber 16, the crankshaft 12 is disposed with both ends thereof supported by bearings 17 fixed to the recoil starter side casing 14 and the cooling fan side casing 15, respectively.

A recoil case 18 having a recoil starter 38 operatively connected to the end of the crankshaft 12 on the recoil starter side is joined to the outer side of the recoil starter side casing 14.

On the other hand, the cooling fan side casing 15
The fan case 1 on the opposite side of the crankcase 13.
9 is integrally provided, and the fan case 19 accommodates the cooling fan 20 fixed to the cooling fan side end portion 12a of the crank shaft 12 therein, and the fan cover 2
1 is joined.

The cooling fan 20 is a magnet rotor 2
It is formed integrally with 2. The magneto rotor 22 is
When the crankshaft 12 is started by the recoil starter 38, a spark is emitted to the ignition plug 24 attached to the top of the cylinder 9 in cooperation with the ignition coil 23 fixed to the inner surface of the fan cover 21. Give rise to.

The fan case 19 is provided with a single opening cooling air suction hole 25 between the crank case 13 and the crank case 13 which is easy to form without ribs or the like.
The cooling air suction hole 2 is provided by the intake action by the rotation of 0.
The outside air sucked from 5 is guided by the fan cover 21 and flows around the cylinder 9 to cool the cylinder fins 26 and the like formed in large numbers on the outer periphery of the cylinder 9.

In the well-known small-sized air-cooled two-cycle gas-soli engine 4 as described above, the foreign matter intrusion prevention member A according to this embodiment is attached to the crankcase 13 as shown in FIGS. 1, 4 and 5. To be

As shown in FIGS. 2 and 3, the foreign matter invasion preventing member A is integrally formed as a whole from a thin steel plate such as bainite steel having a suitable elastic deformability. As the material of the foreign matter invasion preventing member A, other materials such as synthetic resin having appropriate elastic deformability, heat resistance and wear resistance can be used.

The foreign matter invasion preventing member A does not necessarily have to be molded entirely of a material having elastic deformability, and at least a mounting means portion that can be freely attached to and detached from the crankcase 13 is formed. Any material may be used.

The foreign matter invasion preventing member A includes a pair of left and right curved portions 27, 27 facing each other as the attaching means. The curved portions 27, 27 are formed by the recoil starter side casing 14 and the cooling fan side casing 1.
The lower ones 29, 29 of the two upper and lower crankcase assembly bosses 28, 29 formed on a part of the outer surface of 5 are held by elastic deformation. The crankcase assembly boss portion 29 extends in the axial direction of the crankshaft 12 in order to connect the cooling fan side casing 15 and the recoil starter side casing 14 to each other by inserting bolts (not shown). like,
The crankcase 13 is formed on both left and right sides in parallel with each other.

The cooling air suction hole 25 is formed between the pair of left and right crankcase assembly boss portions 29, 29.

The foreign matter intrusion prevention member A uses the pair of left and right crankcase assembly bosses 29, 29 to attach the crankcase 13 to the crankcase 13 by the curved portions 27, 27. A body portion 31 that prevents foreign matter from entering the fan case 19 through the cooling air suction hole 25 without hindering the intake action of the cooling fan 20 is integrally provided with the curved portions 27, 27. .

The main body 31 has the cooling air suction hole 2
5, the ventilation holes 32 are distributed in a rectangular flat plate portion integrated with the bending portion 27, as in the example shown in FIG. In addition to the above, a wire may be used to form a mesh.

The ventilation holes 32 distributed in the body portion 31.
By reducing the area of each individual and increasing the total number of them, it is possible to prevent the entry of relatively small foreign substances.

The body portion 31 is formed with a pair of leg portions 33, 33 positioned so that the projecting end thereof abuts the bottom surface 13a of the crankcase 13 when mounted on the crankcase 13. The pair of legs 33, 33 are in contact with the bottom surface 13a to prevent the foreign matter intrusion preventing member A from being displaced or deformed.

The main body 31 has a lower portion,
An insertable portion 34 that can be engaged and disengaged is integrally formed at the lower edge of the cooling air suction hole 25. The insertion portion 34 is composed of outer flange pieces 35, 35 formed on the left and right ends of the lower portion of the main body 31, and an inner insertion piece 36 formed between the outer flange pieces 35, 35. . As shown in FIG. 3, the outer flange pieces 35, 35 and the inner insert piece 36 are positioned relative to each other by a dimension T corresponding to the thickness of the fan case 19 forming the lower edge of the cooling air intake hole 25. They are staggered. A slit 37 for facilitating elastic deformation is formed in the center of the inner insertion piece 36.

If necessary, the worker attaches the foreign matter intrusion preventing member A according to the present embodiment configured as described above to the engine 4 of the brush cutter as follows.

First, in order to facilitate the work of attaching the foreign matter intrusion prevention member A, the power generation section 3 of the brush cutter is used to
The fuel tank 5 is removed. Then, the engine 4
The lower part of the crankcase 13 is largely opened, and the lower part of the crankcase 13 is exposed.

Therefore, the outer collar pieces 35, 35 are respectively positioned outside the cooling air suction hole 25, and the inner insertion piece 36 is positioned inside the cooling air suction hole 25, and the insertion portion 34 is used for the above-mentioned operation. The lower edge of the cooling air suction hole 25 is held from inside and outside. After that, if the bending portions 27 are pressed against the crankcase assembly boss portion 29, the bending portions 27 are forcibly and temporarily opened in a direction in which they are separated from each other by their elasticity, and the elastic deformation thereof The boss portion 29 for assembling the crankcase is sandwiched from both sides. At this time, the main body portion 31 extends so as to cover the cooling air suction hole 25, and does not interfere with the intake action of the cooling fan 20, and the cooling air suction hole 25 allows the inside of the fan case 19 to be prevented. To prevent foreign objects from entering.

As described above, the foreign matter intrusion preventing member A is
The crankcase 13 is attached using the crankcase assembly boss portion 29 that the crankcase 13 originally has. Therefore, it is possible to retrofit the conventional engine 4 without changing the configuration.

Further, since the insertion portion 34 is provided, the foreign matter intrusion prevention member A can be easily attached to the crankcase 13.

Whether or not the foreign matter intrusion prevention member A is attached to the engine 4 is appropriately determined according to the type of mowing material and the environment around the mowing work. For example, when weeding a weed having relatively thick stems and branches, the cut ends of the stems and branches from the cooling air intake hole 25 are the fan case 1.
When it jumps into the inside 9, the rotation of the cooling fan 20 is hindered. Therefore, the foreign matter intrusion prevention member A is attached before the start of work.

On the other hand, when there is no possibility that foreign matter may enter through the cooling air suction hole 25, in order to avoid unnecessarily restricting the intake action of the cooling fan 20,
The brush cutter may be used without attaching the foreign matter intrusion prevention member A.

If a plurality of foreign matter invasion preventing members having different effective opening areas and distribution patterns of the ventilation holes 32 are prepared, a member having an optimal foreign matter invasion preventing function is appropriately selected according to the type of mowed material. Can be selected and used.
For example, when mowing dead plows, scattered plows of spouts easily enter the cooling air suction holes 25, so that the ventilation holes 32 have a small area.

[Brief description of drawings]

FIG. 1 is a perspective view showing a foreign matter intrusion prevention member and a cooling fan side casing according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view of a foreign matter intrusion preventing member according to the embodiment of the present invention.

FIG. 3 is a side view of the foreign matter intrusion prevention member according to the embodiment of the present invention.

FIG. 4 is a front view showing a mounting state of a foreign matter intrusion prevention member on a cooling fan side casing.

5 is a vertical cross-sectional view of a power generation unit of the brush cutter shown in FIG.

FIG. 6 is an overall schematic view showing a brush cutter as an example of a working machine equipped with an engine using a foreign matter intrusion prevention member according to the present invention.

[Explanation of symbols]

4 Internal Combustion Engine 20 Cooling Fan 25 Cooling Air Suction Hole 27 Mounting Means (Bending Part) 29 Part of Outer Surface of Internal Combustion Engine (Crankcase Assembly Boss) 31 Main Body 33 Misalignment Prevention Means (Leg)

Claims (3)

[Claims] 1. A part (29) of the outer surface of an internal combustion engine (4)
And a mounting means (27) which is detachable by elastic deformation, and inhibits an intake action by a cooling fan (20) of the internal combustion engine (4) when mounted on the internal combustion engine (4) by the mounting means (27). Without cooling air intake hole (25)
Foreign matter intrusion prevention member for an internal combustion engine, comprising: a main body (31) for preventing foreign matter from entering the internal combustion engine (4). 2. The pair of crankcase assembly bosses by elastic deformation acting to sandwich a pair of parallel crankcase assembly boss portions (29, 29) adjacent to each other of the internal combustion engine (4) from both sides thereof. Division (29,2
9) and a cooling fan (2) for the internal combustion engine (4) when attached to the internal combustion engine (4) by the mounting means (27, 27) that is detachable.
Foreign matter intrusion of the internal combustion engine, comprising a body portion (31) for preventing foreign matter from entering the internal combustion engine (4) through the cooling air suction hole (25) without inhibiting the intake action by (0). Element. 3. A position deviation prevention means (33) which is formed on the body part (31) and abuts against a part (13a) of the internal combustion engine (4) to prevent the position deviation of the body part (31). ) The foreign matter intrusion preventing member for an internal combustion engine according to claim 1 or 2, further comprising: