JP2012163088A - Portable working machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a portable working machine, in which woodchips, dust and the like having flowed into a purification chamber can be efficiently discharged.SOLUTION: In the portable working machine including an engine, a carburetor for feeding an air-fuel mixture to a cylinder of the engine, an air filter 31 for purifying air sucked in with the carburetor, and the purification chamber 30 for accommodating the air filter 31 and having a suction port, an opening part 32 for air is provided at a corner part on the gravitation force direction down side from the air filter 31 of the purification chamber 30. A horizontal surface 33 near the opening part 32 is formed and tilted (angle θ) to be lowered toward the opening part 32, and a vertical surface 34 is formed and tilted (angle θ) toward the opening part 32. The shape of the purification chamber 30 is decided so that a ratio of a spatial volume (dashed line 35) is larger near the upper side of the opening part 32.

Description

  The present invention relates to a portable work machine that uses an engine as a power source, and more particularly, to a portable work machine that devises the shape of a purification chamber.

  A portable work machine represented by a chain saw or the like is often used in an outdoor environment with a lot of wood chips and dust. Therefore, an air filter is usually attached to a carburetor that supplies fuel to the engine in order to remove wood chips and dust contained in the intake air for combustion. In addition, in order to reduce the intake noise, a purification chamber that houses a carburetor and an air filter is installed. Patent Document 1 proposes a portable working machine provided with a structure having a mechanism for purifying intake air in order to prevent clogging of an air filter.

JP-A-61-190111

  However, even if these structures are used, it is difficult to completely remove wood chips and dust contained in the intake air. Generally, in a portable work machine, a hole for a tool for operating a screw for adjusting a throttle opening of a carburetor or a fuel flow rate from outside the purification chamber is installed in the purification chamber. Many. Furthermore, since the purification chamber is often configured to be openable and closable by providing a lid member or the like so that the vaporizer and the air filter can be replaced, a clearance is generated on the assembly. For these reasons, it is difficult to completely prevent the inflow of wood chips and dust in the septic chamber, even if there are some differences, and the air filter may be clogged by the inflow of wood chips and dust. is there. Conventionally, there have been few proposals for a structure for efficiently discharging wood chips, dust, and the like after flowing into the purification chamber, and a sufficient effect has not been obtained.

  The present invention has been made in view of the above background, and an object of the present invention is to provide a portable working machine that can efficiently discharge wood chips, dust, and the like flowing into the purification chamber to the outside of the purification chamber. .

  Another object of the present invention is to provide a portable work machine capable of effectively discharging dust flowing into the purification chamber when the engine is idling.

  Still another object of the present invention is to provide a portable work machine that does not lower the effect of discharging wood chips, dust, and the like flowing into the purification chamber due to the inclined posture of the portable work machine.

  The characteristics of representative ones of the inventions disclosed in the present application will be described as follows.

  According to one aspect of the present invention, an engine, a carburetor for sending an air-fuel mixture to a cylinder of the engine, an air filter for purifying air sucked by the carburetor, and an air filter for containing the air filter In the portable working machine having the purification chamber, an opening to the atmosphere is provided at the corner portion below the gravity direction of the air filter in the purification chamber.

  According to another feature of the present invention, in the purification chamber, the horizontal surface in the vicinity of the opening is formed so as to be inclined toward the opening, and the upper and lower surfaces in the vicinity of the opening are inclined toward the opening. It was formed to be formed. The angle formed by the horizontal plane connected to the opening and the upper and lower surfaces is preferably less than 90 degrees.

  According to still another aspect of the present invention, the drive shaft of the engine is disposed so as to be horizontal and perpendicular to the longitudinal direction of the portable work machine, and the purification chamber is disposed on the side of the cylinder extending from the drive shaft. The horizontal plane and the upper and lower planes are planes provided substantially parallel to the longitudinal direction of the portable work machine. A cooling fan is provided on the drive shaft of the engine, and an opening is provided in a corner portion at a position far from the cooling fan in the purification chamber. In the purification chamber, the shape of the purification chamber is determined so that the ratio of the space volume in the vicinity of the opening is increased. It is preferable that the opening has a tubular shape with the wall surface extending downward.

  According to the first aspect of the present invention, in the portable working machine having the purification chamber having the suction port, the opening is provided in the corner portion below the air filter of the purification chamber, so that wood chips and dust flowing into the purification chamber When the engine is idling, it moves to the opening due to gravity and engine vibration, and is discharged to the outside. Therefore, it is possible to suppress the clogging of the air filter due to the stay of wood chips or dust in the purification chamber.

  According to the invention of claim 2, in the purification chamber, the horizontal surface in the vicinity of the opening is formed so as to be inclined toward the opening. Therefore, on the wall surface in the vicinity of the opening of the purification chamber, wood chips, dust, etc. It is possible to efficiently discharge wood chips and dust.

  According to the invention of claim 3, in the purification chamber, the upper and lower surfaces in the vicinity of the opening are formed to be inclined toward the opening, so that the opening can be performed even when the portable working machine is in the horizontal state. Since the part is located on the lower side in the gravity direction in the purification chamber, the same effect as in the first aspect can be obtained. Thus, even when the work is performed in the sideways state, the clogging of the air filter can be further suppressed by efficiently discharging wood chips and dust in the purification chamber.

  According to the invention of claim 4, since the angle formed by the horizontal plane connected to the opening and the upper and lower surfaces is less than 90 degrees, the portable work machine can be tilted to any position between the normal state and the sideways work state. The discharge effect of wood chips and dust from the opening is not lowered.

  According to the fifth aspect of the present invention, the horizontal plane and the upper and lower surfaces are surfaces provided substantially in parallel with the longitudinal direction of the portable work machine. Therefore, the portable work machine is inclined in the normal state or laterally about the longitudinal direction. In this case, wood chips and dust can be discharged from the opening by effectively using the action of gravity.

  According to the sixth aspect of the present invention, since the opening is provided at the corner at a position far from the cooling fan provided on the drive shaft of the engine, the opening is formed at the end on the side where the cooling fan is not installed. Thus, it is possible to prevent wood chips, dust, and the like from approaching from the side where the cooling fan is not installed and flowing into the purification chamber together with the intake air.

  According to claim 7, in the purification chamber, the shape of the purification chamber is determined so that the ratio of the space volume in the vicinity of the opening is increased. Therefore, when the engine speed is high and the suction force is strong, wood chips, dust, etc. Even when it flows into the purification chamber from the opening, the distance from the opening to the air filter in the purification chamber is relatively long, so that it is possible to prevent wood chips, dust, and the like from immediately adhering to the air filter.

  According to the eighth aspect, since the wall surface is extended from the opening toward the lower side, it is possible to prevent wood chips, dust, and the like from approaching the opening from the working tip tool side, and the engine speed can be reduced. Even in a state where the suction force is high and strong, it is possible to prevent wood chips or dust from flowing into the purification chamber from the opening.

  The above and other objects and novel features of the present invention will become apparent from the following description and drawings.

1 is a side view of a chain saw 1 according to an embodiment of the present invention. It is the side view of the chain saw 1 which concerns on the Example of this invention, Comprising: It is the figure which showed a part with sectional drawing. It is the rear view of the chain saw 1 which concerns on the Example of this invention, Comprising: It is the figure which showed a part with sectional drawing. It is the rear view of the chain saw 1 which concerns on the Example of this invention, Comprising: It is the figure which showed one part with sectional drawing of the AA part of FIG. It is a side view which shows the attachment / detachment method to the vaporizer | carburetor 56 of the air filter 31 of FIG. It is the perspective view which looked at the simple substance of the air filter 31 of FIG. 4 from the back side. It is the perspective view which looked at the simple substance of the air filter 31 of FIG. 4 from the front side. 4 is a diagram for explaining a detailed shape of a purification chamber 30. FIG. It is the figure which looked at the purification | cleaning chamber 30 from the top, and is the figure which showed the main body housing 4 and the purification | cleaning chamber cover 29 in the cross section. It is the rear view which shows the state which made the chain saw 1 which concerns on the Example of this invention into the horizontal attitude | position, and is the figure which showed a part with sectional drawing of the AA part of FIG. 4 is a perspective view showing the shape of a purification chamber cover 29. FIG.

  Embodiments of the present invention will be described below with reference to the drawings. In this embodiment, a chain saw 1 will be described as an example of a portable work machine. In the present specification, the direction shown in the figure is defined as the front-rear direction, the up-down direction, the left-right direction, and the description based on the case where the operator holds the chain saw 1.

  FIG. 1 is a side view of a chain saw 1 according to an embodiment of the present invention, and shows a state in which the chain saw 1 is in an upright posture. The chain saw 1 uses a small engine such as a two-cycle or four-cycle engine as a power source, a guide bar 2 protrudes in front of the main body housing 4, and a saw chain (not shown) is a work tip tool on the periphery of the guide bar 2. Z)). By using the chain saw 1 to rotate the saw chain at a high speed by the rotation of the engine, it is possible to cut trees, branches, and the like. A main handle 3 is provided above the chain saw 1, and a front handle 6 is provided so as to extend laterally and downward from the vicinity of the front end of the main handle 3.

  The main handle 3 is a handle for the operator to hold with the right hand, and the front handle 6 is a handle for the operator to hold with the left hand. A safety trigger 7 a is provided near the upper portion of the main handle 3, an ignition switch 7 b (see FIG. 3) described later is provided near the front end, and a throttle trigger 7 c is provided below the main handle 3. A hand guard 12 is provided on the front side of the main handle 3 to protect the operator's hand from being exposed to branches or cuts. The left side portion of the main body housing 4 is covered with a fan cover 10 having a plurality of slits 10a for allowing air to pass therethrough.

  A recoil type starter (not shown) for starting the engine is accommodated inside the fan cover 10, and a starter handle 13 for pulling the starter through the vicinity of the upper portion of the fan cover 10 is attached. A fuel tank and a chain oil tank (not shown) are disposed in the front side of the main body housing 4, and a fuel tank cap 14 and a chain oil tank cap 15 are provided. The main body of the chain saw 1 near the rear end of the main handle 3 is covered with the main body housing 4, and the rear of the main body housing 4 is covered with the purification chamber cover 29. The main body housing 4 is configured by a box-shaped engine housing portion that houses an engine 50 (to be described later) and in which a tank is integrally formed, and a cleaner body to which the purification chamber cover 29 is attached at the rear end of the engine housing portion. The

  In felling work using the chain saw 1, a large amount of wood waste is generated and scattered around. For this reason, if the wood chips are sucked into the engine together with the air, it causes a malfunction such as a malfunction, so that a structure in which the wood chips are not mixed into the intake air is required. Therefore, a purification chamber, which will be described later, is provided in the upper rear portion of the main body housing 4. The purification chamber has an opening surface, and the opening surface is closed by a purification chamber cover 29 fixed by a knob 28. In the vicinity of the main body housing 4 covering the purification chamber, a screw for adjusting the throttle opening and the fuel flow rate for adjusting the rotation speed of the carburetor when idling is adjusted from the outside of the purification chamber using a tool. Therefore, a throttle adjusting screw hole 26 and a fuel adjusting tool insertion hole 25 are provided.

  FIG. 2 is a side view of the chain saw 1 according to the embodiment of the present invention, and a part thereof is a cross-sectional view. A two-cycle engine 50 is housed inside the main body housing 4, and a cooling fan 51 is provided on the drive shaft 54 on the left side of the main body housing 4. The cooling fan 51 is fixed to a drive shaft (crankshaft) 54 of the engine 50 with bolts. The cooling fan 51 functions as a flywheel, and a fin 51a is integrally formed in a part thereof. Around the cooling fan 51, a spiral cooling air passage 60 whose distance from the rotation center gradually increases is installed, and the cooling air is guided to the spiral cooling air passage 60 as indicated by an arrow 61, and the engine 50 and ignition The coil 55 is cooled. A permanent magnet (not shown) for generating high voltage electricity for ignition by an ignition coil 55 is provided on a part of the outer peripheral side of the cooling fan 51. The high voltage electricity generated by the ignition coil 55 is supplied to a spark plug (not shown) by a high voltage cord extending from the ignition coil 55.

  Most of the cooling air generated by the cooling fan 51 is guided to the cylinder portion of the engine 50 as indicated by an arrow 61 and is discharged to the outside of the main body housing 4 after flowing through the outer periphery of the cylinder portion and around the head. On the other hand, part of the cooling air generated by the cooling fan 51 is guided from the intake port 59 in the direction of the arrow 62. The air flow indicated by the arrow 62 is directly or indirectly guided to the purification chamber 30 and is sucked by the engine 50 through a carburetor (not shown). The intake port 59 is disposed in the vicinity of the position where the distance from the center of the cooling fan 51 is minimum in the spiral cooling air passage 60. Note that the air to be sucked by the engine 50 through the carburetor in the purification chamber is formed not only in the air guided through the suction passage in the direction of the arrow 62 but also in the vicinity of the joint between the purification chamber and the purification chamber cover 29. Also flows from a gap (described later), a throttle adjusting screw hole 26 and a fuel adjusting tool insertion hole 25. Therefore, since chips and wood chips may flow into the purification chamber, an air filter (described later) is provided in the purification chamber.

  FIG. 3 is a rear view of the chain saw 1 according to the embodiment of the present invention, and a part thereof is shown in a sectional view. The air flow generated by the cooling fan 51 and guided in the direction of the arrow 62 (see FIG. 2) from the intake port 59 (see FIG. 2) further flows in the direction of the arrow 63 and flows into the purification chamber. The cleaning chamber has an opening surface on the rear side, and the opening surface is covered with a cleaning chamber cover 29. The purification chamber cover 29 is fixed to the main body housing 4 by a knob 28 having a screw portion, and the purification chamber cover 29 is fixed to the main body housing 4 without using a tool such as a screwdriver by rotating the knob 28 by hand. Can be removed. Further, an opening 32 to be described later is exposed on the right side near the center of the purification chamber cover 29.

  A muffler cover 5 is provided on the right side of the main body housing 4. The muffler cover 5 covers a silencer (not shown) disposed inside and serves to protect the worker from heat. On the left side of the main body housing 4, an air guide cover 8 that covers the cooling fan 51 and a fan cover 10 that constitutes a part of the outline of the main body of the portable work machine are provided. The muffler cover 5 and the fan cover 10 are preferably formed of a polymer resin such as plastic, and are fixed to the main body housing 4 with screws, bolts, or the like.

  4 is a cross-sectional view and a rear view as seen from the AA portion of FIG. In the purification chamber 30, a vaporizer (not shown) and an air filter 31 for purifying the intake air are accommodated. The air filter 31 functions to clean the air sucked into the engine, and is attached to the suction port of the carburetor. Here, the shape and attachment method of the air filter 31 will be described with reference to FIGS.

  FIG. 5 is a side view showing a method of attaching / detaching the air filter 31 to / from the vaporizer 56. A cylindrical portion 31c is provided on the front side of the air filter 31, and the cylindrical portion 31c of the air filter 31 is inserted into the end of the connecting pipe 57 as shown by an arrow, and is an inner wall of the cylindrical portion 31c in the circumferential direction. The air filter 31 is attached to the connection pipe 57 by fitting the protrusions 31 d formed at two positions separated by 180 degrees into the attachment grooves 58 formed in the axial direction from the opening of the connection pipe 57. As can be understood from FIG. 5, the shape of the mounting groove 58 is a groove having a substantially L shape when viewed from the outer peripheral side of the connecting pipe 57. When the air filter 31 is pushed in the direction of the arrow, it is guided to the axial groove of the mounting groove 58, and when it abuts on the tip of the axial groove, it is guided to the circumferential groove by rotating the air filter 31 only slightly. Then, the protruding portion 31d contacts the end of the circumferential groove.

  The air filter 31 is configured by fitting a front side housing 31a and a back side housing 31b. The front-side housing 31a and the back-side housing 31b can be separated from each other, and filter members 38 and 39 to be described later can be cleaned.

  FIG. 6 is a perspective view of the air filter 31 as seen from the back side. The back housing 31b and the front housing 31a of the air filter 31 are formed of, for example, plastic. A filter member 39 is disposed inside the rear housing 31b. The filter member 39 allows air from outside to pass through while being filtered, and prevents dust from entering the engine 50. A cut-off portion 31e is formed on the lower right side of the air filter 31, and the outer diameter of the air filter 31 is formed to be cut off obliquely so that the distance between the cut-out portion 31e and the inner wall of the purification chamber 30 is increased. is doing.

  FIG. 7 is a perspective view of the air filter 31 as viewed from the front side. The front housing 31a is formed with a cylindrical portion 31c fitted into the connection pipe 57, and a filter member 38 divided into six sections by a crosspiece is disposed around the cylindrical portion 31c. Protruding portions 31d are formed at two locations on the inner wall of the cylindrical portion 31c. The filter member 38 prevents dust from entering from outside during intake. The filter member 38 attached to the front housing 31a has a shape with a cylindrical hole in the center, and the diameter of the hole corresponds to the outer diameter of the cylindrical portion 31c. Thus, the air filter 31 has a flat shape extending in the axial direction and the vertical direction, and the filter members 38 and 39 are arranged on the front side and the back side, respectively, so that a sufficient capacity can be secured and the air inflow of the carburetor 56 can be secured. Since the front-rear length is short with respect to the direction, a small space can be used effectively even when the engine tool is disposed inside the cover.

  Returning to FIG. 4, the description will be continued. In the purification chamber 30, an opening 32 communicating with the atmosphere is provided at the lower right corner of the purification chamber 30 at the right end of the horizontal wall surface 33 below the air filter 31 in the gravity direction. The horizontal wall surface (horizontal plane) 33 is formed so as to be inclined from the left side to the right side, that is, down toward the opening 32. On the other hand, the vertical wall surfaces (upper and lower surfaces) 34 are formed so as to incline downward from the top, that is, toward the opening 32. The opening 32 is disposed so as to open toward the lower side in the gravitational direction. In the opening 32, an extending part 36 b extending from the wall surface 34 to the lower side in the gravitational direction is formed. Further, in the vicinity of the opening 32, an extending part 36a is formed from the opening 32 toward the lower side in the direction of gravity. The extending part 36 a is a part defined by the wall surface of the purification chamber cover 29. These extending portions 36a and 36b may be formed as parallel walls covering both sides, or may be pipes. At this time, when the extension lines 37a and 37b are drawn downward from the extending portions 36a and 36b, there is no wall surface that intersects them substantially at a right angle. In FIG. 4, it will be understood that other components do not intersect the space (region) in which the purification chamber cover 29 is sandwiched between the extension lines 37 a and 37 b.

  By adopting the shape of the purification chamber 30 as described above, the following situation occurs when the chain saw 1 is in operation. When the engine 50 is started in the chain saw 1, the engine 50 is idling. Then, when the operator pulls the throttle trigger 7c, the rotational speed of the engine 50 increases, and the saw chain starts rotating. At this time, since the rotational speed of the engine 50 is several times higher than the idling rotational speed, the amount of air sucked through the air filter 31 increases. At this time, wood chips or dust may enter the purification chamber 30 for some reason. The path through which wood chips, dust, etc. enter is mainly from the arrow 62 in FIG. 2 through the arrow 63 in FIG. 3, but from the hole 26 for the throttle adjustment screw, the tool insertion hole 25 for the fuel adjustment, It can also flow from the opening 32. Most of the wood chips and dust stay in the space above the opening 32. This is because, in the purification chamber 30, the shape of the purification chamber 30 is determined so that the ratio of the space volume in the vicinity of the opening 32 is large, so that turbulent flow is likely to occur in that space. Moreover, since air containing fine dust is filtered by the air filter 31, some wood chips and dust adhere to the surfaces of the filter members 38 and 39 of the air filter 31.

  Next, when the operator finishes one cutting operation such as cutting a branch and returns the throttle trigger 7c, the engine 50 returns to idling rotation again. When the engine 50 is idling, the wood chips and dust staying in the space above the opening 32 fall downward. Further, among the wood chips and dust adhering to the filter members 38 and 39, the larger one is dropped from the air filter 31 and falls downward because the action of gravity is larger than the suction force of the engine 50. Here, a part of the fallen wood chips and dust stays on the substantially horizontal wall surface 33 below. At this time, since the wall surface 33 vibrates due to the vibration generated from the engine 50, the wood chips and dust dropped on the wall surface 33 gradually move to the right in the drawing, that is, in the direction of the opening 32 due to the inclination of the wall surface 33. When it reaches part 32, it falls downward as shown by arrow K1. At this time, the extended line portion of the opening 32 that extends downward from the opening 32 in the direction of gravity has no intersecting wall surface that hinders the fall, and therefore can be discharged smoothly.

  Next, when the operator pulls the throttle trigger 7c again for cutting work such as cutting the next branch, the rotational speed of the engine 50 increases again, so that the engine 50 enters the purification chamber 30 or is discharged from the opening 32. The wood chips and dust that have not existed are lifted by the suction force again and stay in the space above the opening 32 as described above. However, when the engine 50 is lowered to the idling speed next time, the wood chips and dust fall almost to the upper side of the opening 32, so that the wood chips and dust can be efficiently discharged to the outside through the opening 32. it can.

FIG. 8 is a view for explaining the detailed shape of the purification chamber 30. The purification chamber 30 has a substantially rectangular cross section when viewed from the rear as shown in the figure, and the opening 32 is disposed at a corner portion that is substantially in contact with the wall surface 34 farthest from the cooling fan in the drive shaft direction in the purification chamber. . This corner is located farther from the cooling fan 51 in the drive axis direction (left-right direction). As described above, the wall surface (horizontal surface) 33 in the vicinity of the opening portion 32 is formed so as to be inclined toward the opening portion 32. In the present embodiment, it is formed so as to be inclined by θ _H from the horizontal line. A vertical wall surface (upper and lower surfaces) 34 extending upward from the opening 32 is formed so as to be inclined by θ _V from the vertical line. The direction of the inclination is also important for discharging wood chips and dust. As the wall surface 34 goes down, the wall surface is positioned on the right side, that is, the air filter 31 is seen in the horizontal direction. It is formed so as to be separated from the center point. Further, the wall surfaces 33 and 34 in the vicinity of the opening 32 were formed so as not to have a step or unevenness. The angle formed between the wall surface 33 connected to the opening 32 and the wall surface 34 is less than 90 degrees. Since it comprised in this way, it is easy to move to the opening part 32, and wood chips and dust can be efficiently discharged | emitted to the exterior of the purification | cleaning chamber 30 without stagnating.

  In the purification chamber 30, a space volume ratio in the vicinity of the opening 32 is formed so as to be large like a portion surrounded by a dotted line 35. Since the opening part 32 is opened toward the lower side in the direction of gravity, the action of gravity can be obtained particularly effectively during upright standing, and wood chips can be discharged efficiently. Further, since the wall surface 33 is inclined so that the opening portion 32 is at the lowest side in the direction of gravity, the wood chips can be moved to the opening portion 32 more efficiently by the action of gravity and the vibration of the engine. Wood chips can be discharged. Further, in the sawing operation, wood chips are produced by a saw chain (not shown) attached to the guide bar 2. Therefore, in the chain saw 1, a large amount of wood chips are scattered particularly from the guide bar 2 side, but the extending portions 36a and 36b The wood chips can be prevented from approaching the opening 32 through the extending portions 36a and 36b.

  In the purification chamber 30, the wall surface 33 is formed so that there are no irregularities or steps in the vicinity of the opening 32. Further, in the extension lines 37 a and 37 b that extend downward from the opening 32 in the gravity direction, the opening Since there is no wall surface that intersects the extension lines 37a and 37b at a right angle in the vicinity of 32, even when the suction force increases due to an increase in the rotational speed of the engine or the like, The discharged wood waste does not stay in the vicinity of the opening 32. In addition, since wood chips and dust discharged from the opening 32 do not accumulate on the wall surface around the opening 32, it is possible to prevent the discharged wood chips from being sucked into the purification chamber 30 again.

  Since the opening 32 is directly opened to the atmosphere, even when the cooling air is stopped by stopping the engine, a high-temperature airflow such as natural convection does not flow from the inside of the engine case 16 that houses the engine body. The temperature rise at the time of the engine stop of the purification | cleaning chamber 30 and a vaporizer | carburetor can be suppressed. Furthermore, even when wood chips flow into the purification chamber 30 from the opening 32, such as when the engine speed is high and the suction power is strong, the ratio of the spatial volume in the vicinity of the opening 32 is increased. Since the distance from the opening 32 to the air filter 31 can be made relatively long in the chamber 30, it is possible to suppress immediately adhering to the air filter 31.

  FIG. 9 is a view of the purification chamber 30 as viewed from above, and shows the main body housing 4 and the purification chamber cover 29 in cross section. Most of the air entering the purification chamber 30 flows from the arrow 63 to the arrow 64 in FIG. As can be seen from the figure, the opening 32 is located away from the inlet of the arrow 64. The opening 32 is a corner of the main body housing 4 after the purification chamber cover 29 is removed (in the vicinity of the intersection of the wall surfaces 33 and 34 in FIG. 8) so as to contact the purification chamber cover 29 and the main body housing 4. Be placed. In the present embodiment, the shape of the opening 32 is a substantially rectangular shape when viewed from above, but this shape is not limited to a rectangular shape, and is a shape that easily discharges wood chips and dust that have fallen on the floor surface. Any other shape may be used.

  An inner wall portion 29 g of the purification chamber cover 29 in the vicinity of the opening 32 is formed obliquely so as to be lowered in the direction of the opening 32. Therefore, the wood chips and dust that adhere to the air filter 31 when the engine 50 rotates at a high speed and fall to the floor surface of the purification chamber 30 when the engine 50 returns to the idling state are lowered toward the opening 32. Since it is formed so as to be inclined, it moves in the direction of the opening 32. In particular, since the floor surface also vibrates due to the vibration of the engine 50, wood chips and dust easily move to the opening 32 while being shaken on the floor surface.

  FIG. 10 is a rear view showing a state in which the chain saw 1 according to the embodiment of the present invention is in a horizontal posture, and a part thereof is a cross-sectional view taken along a line AA in FIG. 1. In the chain saw 1, as shown in FIG. 10, the chain saw 1 is laid down 90 degrees rightward so that the left side surface (fan cover 10) is up, and the saw chain is rotated in a horizontal plane to perform the cutting operation. There is. At this time, the cooling fan 51, the fan cover 10, and the vertical portion 6 a of the front handle 6 are positioned on the upper side in the gravity direction with respect to the main body housing 4, and the guide bar 2 is on the lower side in the gravity direction with respect to the main body housing 4. Will be located. Such a working posture is a posture that is frequently used in the felling work, like the upright posture.

Since the opening 32 is provided in the purification chamber 30 on the side farthest from the cooling fan 51 in the driving axis direction, the opening 32 is positioned at the lowest end in the gravity direction in the purification chamber 30 even in the posture when used sideways. It will be. This is because the wall surface 34 is formed so as to be inclined by θ _V from the vertical line when standing upright as shown in FIG. 8, so that the wall surface 34 faces the opening 32 when the chain saw 1 is in the horizontal posture. Since it comes down in the direction of gravity, it has a great effect on discharging wood chips and dust.

  As described above, even in the horizontal posture in which the guide bar 2 is horizontal, wood chips and dust can be efficiently discharged from the opening 32 to the outside of the purification chamber 30 as indicated by the arrow K2 while effectively using the action of gravity. it can. Further, since the wall surface 34 is inclined, the wood waste can be moved more efficiently as indicated by the arrow K by the action of gravity and the vibration of the engine, and the wood waste can be discharged efficiently.

  Next, the shape of the purification chamber cover 29 will be described with reference to FIG. The purification chamber cover 29 is manufactured by integral molding of a polymer resin such as plastic, for example, and its upper inner wall serves as a cover portion 29a that covers the opening of the purification chamber 30, and its lower inner wall is the cylinder head portion of the engine 50. The purifying chamber 30 is shut off from the cylinder of the engine 50 and the spark plug. The cover portion 29b covers a plug cap (both not shown) attached to the spark plug.

  In the vicinity of the opening 32 of the purification chamber 30, a cutout 29 e is formed in the purification chamber cover 29, and this cutout 29 e forms a part of the outline of the opening 32. In addition, the inner wall portion 29g connected to the rear of the notch 29e is formed so as to be inclined gently and gradually from the rear to the front. Further, the inner wall portion 29h is connected so as to have the same height as the wall surface 33 in FIG. 8, and is formed to be inclined so as to descend from the left side toward the right side, that is, toward the opening 32, similarly to the wall surface 33. The Therefore, the wood chips and dust that have fallen on the inner wall portion 29g or 29h are easily guided to the opening 32 by the vibration of the engine 50 and discharged to the outside.

  The left and right side surfaces 29c, 29d of the cover portion 29b are formed substantially in parallel, and in particular, the side surface 29c forms an extending portion 36a. A screw hole 29 f is formed near the center of the purification chamber cover 29, and the purification chamber cover 29 is fixed to the main body housing 4 by passing the knob 28 through the screw hole 29 f.

  With the configuration described above, wood chips, dust, and the like rarely reach the air filter 31 located above the opening 32 in the direction of gravity, and clogging of the air filter 31 is less likely to proceed. In addition, since the purification chamber 30 and the atmosphere are in communication with each other, an ascending airflow due to high-temperature natural convection due to the heat of the engine 50 is less likely to flow into the purification chamber 30 when the engine 50 and the cooling air are stopped. Even when the vaporizer 56 is accommodated, the temperature rise of the vaporizer 56 can be suppressed.

  As mentioned above, although this invention was demonstrated based on the Example, this invention is not limited to the above-mentioned Example, A various change is possible within the range which does not deviate from the meaning. For example, the chain saw has been described as an embodiment of the present invention. However, the present invention is not limited to the chain saw, and has a cooling fan at one end of the drive shaft of the engine and accommodates an air filter and an air filter between the carburetor and the atmosphere. The present invention can be applied to a purification chamber of a portable working machine having a purification chamber.

  Further, in the present embodiment, the wall surface extending from the end portion farthest from the cooling fan is provided in the opening portion 32, but the wall surface extending from all the end portions of the opening portion is provided, and the opening portion is configured in a cylindrical shape. May be. Further, in this embodiment, on the wall surface on the lower side in the gravity direction of the purification chamber, a part of the wall surface is formed in an inclined shape toward the opening from the upper side in the gravity direction toward the lower side in the gravity direction. Also good. Furthermore, in this embodiment, a part of the wall surface is formed on the wall surface on the side far from the cooling fan in the purification chamber so as to be removed from the cooling fan side and away from the cooling fan toward the opening, but in a stepped shape. You may form in.

  In the present embodiment, no wall surface is arranged on the extension of the opening. However, if the wall does not intersect at a substantially right angle, for example, a wall surface of about 45 degrees with respect to the extension line of the opening may be arranged. I do not care. Further, even in a state where the engine speed is high and the suction force is strong, a substantially perpendicular wall surface may be disposed as long as the engine is sufficiently away from the opening to the extent that the suction force of the engine does not reach through the opening. .

DESCRIPTION OF SYMBOLS 1 Chain saw 2 Guide bar 3 Main handle 4 Main body housing 5 Muffler cover 6 Front handle 6a (front handle) vertical part 7a Safety trigger 7b Ignition switch 7c Throttle trigger 8 Wind guide cover 10 Fan cover 10a Slit 12 Hand guard 13 Starter handle 14 Fuel tank cap 15 Chain oil tank cap 16 Engine case 25 Fuel adjustment tool insertion hole 26 Throttle adjustment screw hole 28 Knob 29 Purification chamber cover 29a, 29b (Purification chamber cover) Cover portions 29c, 29d (Purification chamber cover) ) Side surface 29e Notch 29f (of the purification chamber cover) Screw holes 29g, 29h (of the purification chamber cover) Inner wall portion 30 (of the purification chamber cover) Purification chamber 31 Air filter 31a Front side how 31b Back side housing 31c Cylindrical part 31d Projection part 31e Cut-off part 32 Opening part 33, 34 Wall surface 36a, 36b Extension part 37a, 37b Extension line 38, 39 Filter member 50 Engine 51 Cooling fan 51a Fin 54 Drive shaft 55 Ignition coil 56 Vaporizer 57 Connecting pipe 58 Mounting groove 59 Inlet 60 Spiral cooling air passage

Claims (8)

Engine,
A carburetor for sending an air-fuel mixture to the cylinder of the engine;
An air filter for purifying air sucked by the vaporizer;
In a portable work machine having a purification chamber that houses the air filter,
A portable work machine, wherein an opening is provided in the vicinity of a corner below the air filter of the purification chamber.   2. The portable work machine according to claim 1, wherein the purifying chamber is formed so as to be inclined such that a horizontal plane in the vicinity of the opening is lowered toward the opening.   3. The portable work machine according to claim 2, wherein in the purification chamber, upper and lower surfaces in the vicinity of the opening are formed to be inclined toward the opening.   The portable work machine according to claim 3, wherein an angle formed between the horizontal plane connected to the opening and the upper and lower surfaces is less than 90 degrees. The drive shaft of the engine is arranged to be vertical and horizontal with the longitudinal direction of the portable work machine,
The purification chamber is disposed on a side of a cylinder extending from the drive shaft,
5. The portable work machine according to claim 2, wherein the horizontal plane and the upper and lower surfaces are surfaces provided substantially parallel to a longitudinal direction of the portable work machine. A cooling fan is provided on the drive shaft of the engine;
6. The portable work machine according to claim 5, wherein the opening is provided in a corner portion at a position far from the cooling fan in the purification chamber.   The portable working machine according to claim 6, wherein the shape of the purification chamber is determined so that a ratio of a space volume in the vicinity of the opening is increased in the purification chamber.   The portable work machine according to claim 7, wherein a wall surface extends downward from the opening.

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