JPS6235890Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a portable cutting machine driven by an internal combustion engine, and more particularly to a cutting machine that can be operated by a person without sufficient knowledge of handling the machine without causing any breakdown or damage.

A portable cutting machine driven by an internal combustion engine is usually called an engine cutter.It is equipped with a small two-stroke engine as the drive source, and rotates a thin cutting blade (such as a cutting wheel) via a transmission belt, and cuts ferrous and non-ferrous materials. A portable mechanical tool designed to cut metal materials, concrete members, etc., and used for the above purpose in locations where power sources such as electricity or compressed air are not readily available.

The present invention has been made to improve the efficiency of use of such machines, especially at civil engineering construction sites. One of the characteristics of the working environment at civil engineering construction sites is the poor working environment for the combustion purpose of internal combustion engines. Particularly in areas where engine cutters are used, the local atmosphere contains a large amount of fine dust from the steel, concrete, etc. being cut, so care must be taken to prevent this dust from entering the fresh air taken into the engine. Various innovations must be made to the air filter mechanism. Furthermore, in such work sites, the workers handling the machines are not specified. Since no license is required to operate this cutting machine,
This machine is often used by workers who are unable to distinguish between different types of engines or who lack mechanical knowledge. The following two problems occur in such a case.

a Since it is a 2-cycle engine, it must use gasoline mixed with lubricating oil as fuel, but when refueling, only gasoline is refilled.

b. If the air filter becomes clogged, it should be cleaned, but instead of cleaning it, the machine continues to be used with the air filter removed.

As a result, foreign matter may enter the cylinder, or the cylinder and piston may seize due to lack of lubrication, resulting in major damage to the machine.

The present invention is to provide a cutting machine that eliminates the causes of failure as described above, and aims at economical effects such as extending the operating life of the machine and reducing maintenance costs.

Embodiments of the present invention will be described in detail below with reference to the drawings.

The portable cutting machine of the present invention shown in Fig. 1 is a small
A cycle engine 1 is used as a driving source, and the rotation of this engine rotationally drives a thin cutting blade (cutting grindstone) 2 via a transmission belt (not shown). A casing 4 having a handle 3 surrounds the engine, and a cartridge type fuel tank 5 is attached below. A V-belt housing 6 is attached to the engine crankcase (not shown), and the V-belt is stretched between a pulley fixed to the crankshaft and a pulley fixed to the cutting blade 2. The cutting blade 2 is provided with a substantially semicircular guard 7 to prevent danger to the operator. A handlebar 8 is further attached to the V-belt housing and is arranged perpendicular to the plane of rotation of the cutting blade.

At the rear of the casing 4 is an air filter unit 9.
is installed to supply clean air to the carburetor of the engine 1. A large muffler 10 is attached near the exhaust port of the engine to reduce exhaust sound and noise.

As shown in FIG. 2, the cartridge type fuel tank 5 is provided with a fuel filler port 11 and a fuel supply plug 12. The tank 5 is further provided with a mounting tab 13. The fuel tank 5 contains fuel adjusted to a predetermined mixture ratio (eg, 25 parts gasoline to 1 part oil). When the fuel tank 5 is not in use, the supply tap 12 is covered with a rubber cap or the like. Fuel is supplied from the supply tap to the supply port 17 of the carburetor 16 from the fuel pipe 15 via the fuel system passage 27 (FIG. 5) of the main body. Since the tip of the supply port 17 of the carburetor has a plug-like shape as shown in FIG. 3, the fuel pipe 15 is inserted airtightly. Clean air from the air filter unit 9 is supplied to the air supply port 18 of the carburetor 16, and is mixed and vaporized with fuel from the fuel pipe.

As shown in FIG. 4, the main body of the fuel filler port 11 of the fuel tank is fixed to the tank wall 5 by heat fusion or welding. A disk-shaped valve 19 is mounted inside the fuel filler main body, and this valve is always pushed up by a coil spring 20 so as to be closed. Several windows 21 are bored on the lower outer periphery of the fuel filler main body, and when filling fuel, a specially shaped fuel injection nozzle (not shown) that fits the fuel filler port is passed through the windows while pushing down the disc-shaped valve 19. Mixed fuel is injected. Fuel filler port 11
Furthermore, a ventilation hole 14 is provided.

The air filter unit is installed as shown in FIG. That is, the air filter is constructed as a unit 9 that cannot be easily disassembled, and this unit is provided with mounting tabs 22 and locking projections 23, respectively. The locking protrusion 23 is located in the recess 2 of the casing 4.
4, and the mounting tab 22 is engaged with the machine body 2.
It is attached to the end of 5 by a butterfly type screw 26. A fuel system passage 27 communicating with the fuel tank 5 is provided in this part of the machine body, and a valve hole 28 is formed perpendicular to this passage. A cylindrical valve 30 having a through hole 29 is inserted into the valve hole 28 and is pressed toward the butterfly screw 26 by a push-up spring 31 . The spring 31 is placed in place by a set screw 32.

Therefore, as shown in FIG. 5, when the butterfly screw 26 is tightened, that is, when the air filter unit 9 is installed, the fuel system passage 27 is open.
When the butterfly screw 26 is loosened, the cylindrical valve 30 is pushed up by the action of the spring 31, and the fuel system passage 27 is closed.

In this manner, when the air filter unit 9 is attached to the cutting machine body, the means of attachment is used to open the fuel system passage of the machine body, so that unless the air filter unit 9 is attached, fuel will not enter the engine.
Therefore, the structure is such that the cutting machine cannot be driven with the air filter removed.

As detailed above, the present invention consists of a removably attached cartridge-type fuel tank containing fuel adjusted to a predetermined mixture ratio, so there is no risk of accidentally driving the cutting machine with other fuel. do not have.

Furthermore, if the air filter becomes clogged, the cutting machine will not operate unless a new air filter is installed, so there is no risk of foreign matter getting into the engine cylinder and shortening the life of the engine.

It goes without saying that the present invention can be applied not only to cutting machines but also to impact machines or chainsaws driven by internal combustion engines.

[Brief explanation of the drawing]

Figure 1 is a front view of the cutting machine according to the invention, Figure 2 is a front view of the cutting machine according to the present invention;
Figure 3 is a perspective view of the fuel tank and carburetor, Figure 3 is a sectional view showing how the fuel pipes are connected, Figure 4 is an enlarged sectional view of the fuel filler port, and Figure 5 is a section showing how the air filter unit is installed. FIG. 1... Engine, 2... Cutting blade, 4... Casing, 5... Fuel tank, 6... V-belt housing, 7... Guard, 9... Air filter unit, 10... Muffler, 11... Fuel filler port , 12...
Supply tap, 14...Vent hole, 15...Fuel pipe,
16... Carburetor, 19... Disc-shaped valve, 20... Coil spring, 25... Machine body, 27... Fuel system passage, 28... Valve hole, 30... Cylindrical valve, 31...
Push up spring.

Claims (1)

[Scope of utility model registration request] A portable cutting machine equipped with a small internal combustion engine and rotating a cutting blade via a transmission belt has a removable cartridge-type fuel tank 5 with a refueling hole structured so that it cannot be easily filled with fuel, and a main body of the machine. A removable air filter unit 9, a fuel system passage 27 provided in the machine body and communicating with the fuel tank 5, and a valve hole in which a cylindrical valve 30 having a through hole 29 and slidably intersects with the passage is provided. 28, wherein the cylindrical valve 30 is biased by a spring 31 to open the fuel system passage 27 only when the air filter unit 9 is attached.