JP2015112081A - Portable work machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a structure of a side part cover attached to an engine exhaust side of an engine case to improve rigidity to shaking and distortion of the engine case, and improve detaching/attaching working efficiency of a work component.SOLUTION: There is provided a portable work machine in which an engine is arranged in an internal space of an engine case that is formed in a U-shape in a side view, and which has: a side part cover 6 attached to an engine exhaust side of the engine case; and an operation handle 7 arranged on an upper wall of the engine case. The side part cover 6 is divided into a muffler cover 10 covering the engine exhaust portion and a drive part cover 11 covering a rotary drive part driven by the engine, the muffler cover 10 is fixed by a U-shaped root part of the engine case and middle parts of upper and lower plate parts extending from the root part, and the drive part cover 11 is detachably installed between the upper and lower plate parts of the engine case at a front side of the muffler cover 10.

Description

  The present invention relates to a portable work machine such as a chain saw, a brush cutter, a blower or the like that uses an engine as a power source. More specifically, the structure of a side cover attached to the engine exhaust side of the engine case is improved, and the engine case is shaken. The present invention relates to a portable work machine that improves the rigidity against deformation and improves workability of attaching and detaching work parts.

  A conventional portable working machine of this type, for example, a chain saw, has an engine disposed in an inner space of an engine case formed in a U shape in a side view, and a side cover attached to the engine exhaust side of the engine case, And an operation handle disposed on the upper wall of the engine case (see, for example, Patent Document 1).

US Pat. No. 7,168,132

  However, in the chain saw described in Patent Document 1, the side cover attached to the engine exhaust side of the engine case is formed as a single body and extends long in the front-rear direction. The long side cover is connected to the front side of the engine case. It was attached with one screw. And, in order to mount the guide bar and saw chain, which are work parts for cutting work such as wood, the entire side cover was removed and the guide bar and saw chain were attached to the front side of the engine case .

  In this case, after removing the entire long side cover, a guide bar and a saw chain are attached to the front side of the engine case, and then the entire side cover is aligned and attached to the engine case again. After the work, the guide bar and the saw chain were removed by the reverse procedure. In addition, a front hand guard for applying a brake for emergency stop of cutting work is also attached to the side cover. Therefore, it cannot be said that the workability of attaching and detaching the guide bar, the saw chain, and the side cover is good.

  Further, since the side cover is only screwed and attached to one part of the engine case formed in a U shape in a side view, for example, it is possible to suppress vibration and deformation of the engine case that is shaken by driving the engine. It was impossible. In other words, the side cover merely covers the side surface of the engine case, and does not give rigidity to the shaking and deformation of the engine case. In addition, the operation handle disposed on the upper wall of the engine case may vibrate due to the shaking of the engine case.

  Therefore, the problem to be solved by the present invention that addresses such problems is to improve the structure of the side cover attached to the engine exhaust side of the engine case and improve the rigidity of the engine case against shaking and deformation. In addition, an object of the present invention is to provide a portable working machine that improves workability of attaching / detaching work parts.

  In order to solve the above-mentioned problems, a portable work machine according to the present invention has an engine disposed in an inner space of an engine case formed in a U shape in a side view, and a side cover attached to the engine exhaust side of the engine case. And an operating handle disposed on the upper wall of the engine case, wherein the side cover is covered with a muffler cover that covers an engine exhaust portion, and the rotational drive is driven by the engine. The muffler cover is fixed at a U-shaped root portion of the engine case and an intermediate portion of upper and lower plate portions extending from the root portion, and the drive portion cover is fixed to the muffler cover. It is detachably mounted between the upper and lower plate parts of the engine case on the front side of the cover.

  According to the portable working machine of the present invention, the side cover attached to the engine exhaust side of the engine case formed in a U shape in a side view, the muffler cover covering the engine exhaust part, and the rotational drive driven by the engine And the muffler cover is fixed at the U-shaped root portion of the engine case and the middle portion of the upper and lower plate portions extending from the root portion, thereby swaying and deforming the engine case. Can be improved in rigidity. Therefore, the shake and deformation of the engine case due to the driving of the engine can be suppressed. Further, the drive unit cover is detachably mounted between the upper and lower plate portions of the engine case on the front side of the muffler cover, so that the drive unit cover can be mounted when the work part is attached to or detached from the front side of the engine case. Therefore, the workability of attaching / detaching work parts can be improved.

It is a right view which shows embodiment of the portable working machine by this invention. It is a right view which shows the state which removed the drive part cover in the said portable working machine. It is a right view which shows the state which removed the work component further in the said portable working machine. It is a disassembled perspective view which shows the engine case, muffler cover, etc. which comprise the said portable working machine. It is an expansion perspective view which shows the state which looked at the said muffler cover from the back surface side. It is an expansion right view which shows the drive part cover of the state removed.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1 is a right side view showing an embodiment of a portable working machine according to the present invention, FIG. 2 is a right side view showing a state in which a drive unit cover is removed in FIG. 1, and FIG. 3 is a further work in FIG. It is a right view which shows the state which removed components. FIG. 4 is an exploded perspective view showing a part of the parts constituting the portable work machine.

  This portable work machine is applied to a chain saw, a brush cutter, a blower, and the like using an engine as a power source. FIGS. 1 to 3 show examples in which the present invention is applied to a chain saw. A chain saw as a portable work machine is a type of engine case that is formed in a substantially U-shape when viewed from the side by attaching a guide bar 2 and a saw chain 3 as work parts and cutting the wood by driving the engine. 4 (see FIG. 4), the engine 5 (see FIG. 1) is disposed in the inner space, and the side cover 6 attached to the engine exhaust side of the engine case 4 and the operation disposed on the upper wall of the engine case 4 And a handle 7 for use. The operation handle 7 may be called a top handle, and a chain saw having such a top handle is called a top handle chain saw or a top handle saw. Moreover, in FIG. 1, the code | symbol 8 shows the front hand guard which applies the brake of the emergency stop of a cutting | disconnection operation | work.

  The work component 1 is used for cutting wood or the like, and is wound around an elongated plate-like guide bar 2 connected in the vicinity of a rotation drive unit driven by an engine, and a peripheral portion of the guide bar 2. It consists of a traveling saw chain 3.

  The engine 5 for driving the work component 1 is disposed in the inner space of the engine case 4 shown in FIG. The engine case 4 is a base member on which the engine 5 is mounted. The engine case 4 is formed in a substantially U shape in a side view. The engine 5 is disposed in an inner space of the U shape, and a U-shaped root portion 4a. Is provided with a fuel tank 9. Due to the presence of the fuel tank 9, the root portion 4a of the engine case 4 becomes heavy.

  A side cover 6 is attached to the engine exhaust side of the engine case 4 as shown in FIG. The side cover 6 covers the entire side surface of the engine case 4 on the engine exhaust side. In the present invention, the side cover 6 is divided into a muffler cover 10 and a drive unit cover 11.

  The muffler cover 10 covers the engine exhaust part, and allows high-temperature exhaust gas discharged from the muffler extending from the engine 5 and high-temperature cooling hot air that has cooled the engine 5 to pass through, as shown in FIG. Further, the U-shaped root portion 4a of the engine case 4 is fixed to the middle portion of the upper plate portion 4b and the lower plate portion 4c that extend from the root portion 4a in a U-shape. That is, a locking projection 12 formed on the outer surface of the root portion 4a of the engine case 4 and a locking hole portion 13 formed at a location corresponding to the locking projection 12 of the engine case 4 of the muffler cover 10 are provided. The muffler cover 10 is fixed to the root portion 4a of the engine case 4 by fitting. Further, the screw holes cut in the upper and lower end portions on the opposite side of the muffler cover 10 to the locking hole portion 13 are passed through screws 14a and 14b to intermediate portions of the upper plate portion 4b and the lower plate portion 4c of the engine case 4. The muffler cover 10 is fixed to the middle portion of the upper plate portion 4b and the lower plate portion 4c of the engine case 4 by screwing into the cut screw holes 15a and 15b. The muffler cover 10 may be fixed to the root portion 4a of the engine case 4 with screws.

  In this way, the muffler cover 10 is fixed between the U-shaped root portion 4a of the engine case 4 and the middle portions of the upper and lower plate portions 4b and 4c extending from the root portion 4a, whereby the rigidity of the engine case 4 against vibration and deformation is fixed. The engine case 4 can be prevented from being shaken or deformed by driving the engine 5. In FIG. 4, reference numeral 22 denotes an intake plate attached to the upper plate portion 4b of the engine case 4, and reference numeral 23 denotes a heat insulating sheet attached to the lower plate portion 4c.

  FIG. 5 is an enlarged perspective view showing the muffler cover 10 as viewed from the back side. The muffler cover 10 is a resin cover, and has an air hole 16 through which cooling hot air passes and an air hole 17 through which exhaust gas passes. The air holes 16 through which the cooling hot air passes allow the high-temperature cooling hot air that has cooled the engine 5 to pass through. The air holes 16 extend in the longitudinal direction of the engine case 4 shown in FIG. 4 and are formed in a plurality of elongated shapes. The exhaust hole 17 through which the exhaust gas passes allows the hot exhaust gas of the engine 5 to pass through. The air hole 17 extends in the longitudinal direction of the engine case 4 and has one large rectangular hole.

  The muffler cover 10 has reinforcing ribs 18 inside. The reinforcing rib 18 increases the strength of the muffler cover 10 in which the air hole 16 through which the cooling hot air passes and the air hole 17 through which exhaust gas passes are formed. The air hole 16 through which the cooling hot air passes and / or the air hole 17 through which the exhaust gas passes. It is arranged so as to intersect. The angle may be appropriate, but may be an inclination angle of about 40 degrees with respect to the vertical axis of the muffler cover 10, for example. An elongate reinforcing frame 19 that is bent inward of the muffler cover 10 is formed on the front end side (the left end in FIG. 5) of the muffler cover 10. Strength is increased. Such a reinforcing structure of the muffler cover 10 can suppress shaking and deformation of the operating handle 7 shown in FIG.

  On the other hand, the drive unit cover 11 covers a rotation drive unit driven by the engine 5, and is called a chain cover in a chain saw, and is rotationally driven by the work part 1 including the guide bar 2 and the saw chain 3 shown in FIG. The clutch 20 for transmitting force and its peripheral part are covered, and as shown in FIG. 1, the upper and lower plate parts 4b, 4c of the engine case 4 (see FIG. 4) are provided on the front side of the muffler cover 10. It is detachably mounted between them. That is, by loosening the fastener 21 such as a hexagon nut shown in FIG. 1, the drive unit cover 11 can be removed as shown in FIG. 2, and the drive unit cover 11 is set on the front side of the muffler cover 10. By tightening the fastener 21, the drive unit cover 11 is attached as shown in FIG. 1.

  FIG. 6 is an enlarged right side view showing the drive unit cover 11 in a removed state. The drive unit cover 11 is a resin cover and has an appropriate shape that covers the clutch 20 and its peripheral portion shown in FIG.

  In FIG. 4, a recoil starter for starting the engine 5 is assembled on the side surface of the engine case 4 opposite to the muffler cover 10, and a starter case 24 with a large number of air holes for cooling air is attached to the side wall. . The starter case 24 is attached to the side surface of the engine case 4 opposite to the muffler cover 10 by screwing with a plurality of screws 25 (for example, four or more points). As a result, the engine case 4 is improved in rigidity against shaking and deformation of the engine case 4 by the structural members attached to the left and right side portions. From these things, it suppresses that the root part 4a provided with the fuel tank 9 of the engine case 4 shakes and vibrates in the vertical direction. Further, the load from the operation handle 7 shown in FIG. 1 is supported, and the transmission of shaking to the handle 7 is suppressed.

  Next, the use of the portable work machine configured as described above will be described with reference to FIGS. First, in FIG. 1, when the portable working machine of the present invention is used as a chain saw, an operation handle with the guide bar 2 and the saw chain 3 as work parts 1 mounted on the front side of the engine case 4 is mounted. 7 is held and the wood is cut by driving the engine. When the guide bar 2 and the saw chain 3 are to be serviced or exchanged, the fastener 21 that holds the drive unit cover 11 shown in FIG. Remove the cover 11. In this state, the muffler cover 10 remains attached to the base side of the engine case 4.

  Next, in FIG. 2, the guide bar 2 and the saw chain 3 are serviced or replaced with the drive unit cover 11 removed. FIG. 3 shows a state where the guide bar 2 and the saw chain 3 are further removed from the state shown in FIG. In FIG. 3, reference numeral 26 indicates a spike that is engaged so that the object and the chain saw do not shift when cutting wood or the like.

  Next, in FIG. 3, when other guide bars 2 and saw chains 3 are mounted, or other work parts are mounted, these work parts are placed on the front side of the engine case 4 as shown in FIG. After the mounting, as shown in FIG. 1, the drive unit cover 11 is attached to the front side of the muffler cover 10, and the fastener 21 is tightened to fix the drive unit cover 11. At this time, the drive unit cover 11 is divided from the muffler cover 10 to be smaller than the conventional side cover, and since no other members are attached, the drive unit cover 11 is easily attached and detached. As described above, since the drive unit cover 11 can be easily attached and detached, the workability of attaching and removing work parts such as the guide bar 2 and the saw chain 3 is also improved.

DESCRIPTION OF SYMBOLS 1 ... Work part 2 ... Guide bar 3 ... Saw chain 4 ... Engine case 4a ... Root part 4b ... Upper board part 4c ... Lower board part 5 ... Engine 6 ... Side part cover 7 ... Operation handle 9 ... Fuel tank 10 ... Muffler Cover 11 ... Driver cover 16 ... Air hole through which cooling hot air passes 17 ... Air hole through which exhaust gas passes 18 ... Reinforcing rib 24 ... Starter case

Claims (5)

An engine is disposed in an inner space of an engine case formed in a U shape in a side view, a side cover attached to the engine exhaust side of the engine case, and an operation handle disposed on an upper wall of the engine case; A portable working machine having
The side cover is divided into a muffler cover that covers an engine exhaust part and a drive unit cover that covers a rotation drive unit that is driven by the engine,
The muffler cover is fixed with a U-shaped root portion of the engine case and an intermediate portion of upper and lower plate portions extending from the root portion,
The portable working machine, wherein the drive unit cover is detachably mounted between the upper and lower plate portions of the engine case on the front side of the muffler cover.   The portable work machine according to claim 1, wherein the muffler cover has an air hole through which cooling hot air that has cooled the engine passes, and an air hole through which engine exhaust gas passes.   The portable work machine according to claim 2, wherein the air hole for passing the cooling hot air and the air hole for passing the exhaust gas are formed to extend in a longitudinal direction of the engine case.   4. The portable work machine according to claim 2, wherein the muffler cover has a reinforcing rib disposed so as to intersect with an air hole through which the cooling hot air passes or an air hole through which exhaust gas passes.   The portable working machine according to any one of claims 1 to 4, wherein a fuel tank is provided at a base of the U-shape of the engine case.