JP2011214512A - Engine tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an engine tool capable of making oil a mist with a low-cost and simple structure and supplying the oil to a driving part without being affected from the attitude of an engine.SOLUTION: The engine tool includes a crank chamber 16, an oil chamber 25 communicating with the crank chamber 16 through a communication part and having oil 24 accumulated therein, the driving part 21, etc. which are lubricated with the oil 24. In the engine tool, the communication part is provided in a part of a partition wall 26 partitioning the crank chamber 16 and the oil chamber 25, and includes a communication hole 27 providing communication between the crank chamber 16 and the oil chamber 25, a first valve 28 provided in the communication hole 27 and allowing communication in one direction from the crank chamber 16 to the oil chamber 25, and a first connection member 30 having one end connected to the communication hole 27 and the other end opened in the oil 24.

Description

  The present invention relates to an engine tool using an engine in two cycles or four cycles, such as a chain saw, a blower, and a brush cutter.

  In a conventional engine tool, as a method of supplying the oil stored in the oil chamber to the drive unit, the accumulated oil is stirred with a rotating object, and the mist-like oil is circulated and adhered to the drive unit, Alternatively, the oil sucked from the oil chamber by the pump is discharged to the sliding portion.

JP 10-317931 A

  In an engine tool used in an inclined or inverted position, it is necessary to separate the crank chamber from the oil chamber. In the conventional structure in which the accumulated oil as described above is stirred and mist-like oil is circulated and adhered, it is necessary to provide a rotating object for stirring in the oil chamber. Since the rotating body is provided at the end of the crankshaft, the crankshaft needs to have a structure for sealing the crank chamber and the oil chamber. Moreover, in the conventional structure which lubricates oil with a pump, since a pump must be provided, it becomes a complicated structure and a price will also become expensive.

  Therefore, an object of the present invention is to provide an engine tool that can make oil mist with an inexpensive and simple structure and supply oil to a drive unit without being affected by the attitude of the engine.

  An object of the present invention is to provide an engine tool having a crank chamber, an oil chamber in which oil communicates with the crank chamber via a communication portion, and a drive portion lubricated by the oil. A communication hole that is provided in a part of a partition wall that partitions the chamber and the oil chamber, communicates the crank chamber and the oil chamber, and communicates in one direction from the crank chamber to the oil chamber provided in the communication hole. And a first connecting member having one end connected to the communication hole and the other end opened into the oil.

  By setting it as such a structure, oil mist can be produced | generated by a cheap and simple structure.

  And a piston that reciprocates in a cylinder connected to a crankcase forming the crank chamber, and air in the crank chamber is circulated in the oil via the first connecting member in accordance with the reciprocation of the piston. It is preferable that oil mist is generated in the oil chamber by being discharged into the oil chamber.

  By setting it as such a structure, oil mist can be easily produced | generated according to the reciprocation of a piston.

  The oil chamber is provided with a second communication portion, and the second communication portion includes a suction port into which the oil mist enters, and a drive unit that communicates with the suction port and is driven in accordance with the reciprocation of the piston. It is preferable that the oil mist is supplied from the suction port to the drive unit via the second connection member.

  With such a configuration, oil mist can be easily supplied to the drive unit in accordance with the reciprocation of the piston, so that the drive unit can be lubricated with a simple configuration.

  The second connecting member preferably connects the oil chamber and the rocker arm chamber.

  With such a configuration, oil mist can be supplied to the rocker arm chamber, so that the rocker arm, which is a drive unit located in the rocker arm chamber, can be lubricated.

  A connecting passage that connects the rocker arm chamber and the crank chamber; and a second valve that allows one-way communication from the connecting passage to the crank chamber. It is preferable to open and close according to the reciprocation.

  With such a configuration, oil that has flowed into the rocker arm chamber in accordance with the reciprocating motion of the piston can be returned to the oil chamber via the crank chamber, so that wasteful consumption of oil can be suppressed.

  Moreover, it is preferable that the said suction inlet is located above the upper surface of the said oil.

  By setting it as such a structure, oil mist can be reliably supplied to a drive part via a suction inlet.

  Moreover, it is preferable that the said 1st connection member is a tube which can be bent freely.

  With such a configuration, the tube can be positioned in the oil without being affected by the attitude of the engine, and oil mist can be generated stably.

  Moreover, it is preferable that a weight is provided at the other end of the first connecting member.

  With this configuration, the weight is provided at the other end of the tube, so that the tube can be positioned in the oil even when the engine is tilted. Can be generated.

  A second connecting member that connects the oil chamber and the rocker arm chamber; a connection passage that connects the rocker arm chamber and the crank chamber; and a first passage that allows one-way communication from the connection passage to the crank chamber. It is preferable to have two valves.

With this configuration,

  According to the present invention, an oil mist can be reliably generated without being affected by the attitude of the engine such as inclination or inversion with an inexpensive and simple structure, and the oil supply to the drive unit can be stably performed. An engine tool that can be provided can be provided.

1 is an overall view of a brush cutter as an embodiment of an engine tool according to the present invention. Sectional drawing of the engine mounted in the engine tool used as this invention. Sectional drawing which shows the time of piston fall of FIG. Sectional drawing which shows the time of piston raising of FIG. The whole chain saw which is another Example of the engine tool used as this invention. Sectional drawing of the engine which shows the state which inclined to the one side from the state of FIG. Sectional drawing of the engine which shows the state inverted from the state of FIG. FIG. 3 is a cross-sectional view of the engine showing a state inclined from the state of FIG. 2 to the other side.

  Hereinafter, a brush cutter will be described as an embodiment of an engine tool according to the present invention with reference to FIGS. 1 to 7.

  First, a brush cutter for an engine tool according to the present invention will be described with reference to FIG. As shown in FIG. 1, the brush cutter 1 includes an engine 2 serving as a power source for the rotary blade 6, an engine 2 on one end side, and the rotary blade 6 on the other end side, and transmits the rotation of the engine 2 to the rotary blade 6. A long pipe 3 containing a drive shaft (not shown), a handle 4 attached to the long pipe 3 and gripped by an operator, and a blade attachment portion attached to the other end of the long pipe 3 to which the rotary blade 6 is attached. 5 and a protective cover 7 that prevents scattering to the worker side when the cutting operation is performed by the rotary blade 6.

  When the mowing operation is performed by the brush cutter 1, the engine 2 is started, the operator grips the handle 4, and operates a throttle lever (not shown) attached to the handle 4. When the rotation of the engine 2 is transmitted to the rotary blade 6 through the drive shaft by lever operation, the rotary blade 6 rotates and the pruning operation can be performed. In addition, the rotational speed of the rotary blade 6 can be adjusted according to the pulling amount of the lever.

  Next, the configuration of the engine 2 mounted on the brush cutter 1 will be described with reference to FIG. FIG. 2 is a cross-sectional view of the engine 2 during normal use (upright standing) (a cross section in a direction perpendicular to the longitudinal direction of the long pipe 3). As shown in FIG. 2, the engine 2 includes a piston 9 that reciprocates in the cylinder 8 in the vertical direction in the figure, and a crankcase 11 that holds the cylinder 8 and rotatably holds a crankshaft 10. The cylinder 8 constitutes a combustion chamber 8a together with the piston 9, and holds an intake valve and an exhaust valve 12 corresponding to each port for opening and closing an unillustrated intake port and exhaust port. The reciprocating motion of the piston 9 is transmitted to the crankshaft 10 through the connecting rod 13 connected to the piston 9 and converted into rotational motion, and the rotational motion of the crankshaft 10 is transmitted to the drive shaft through a clutch (not shown). Is transmitted to the rotary blade 6.

  A gear 14 is provided on the outer periphery of the crankshaft 10, and the rotation of the crankshaft 10 is transmitted to a camshaft 18 having a cam 17 in the crank chamber 16 via a cam gear 15 that engages with the gear 14.

  One end of a tappet 19 slidable in a direction (vertical direction in FIG. 2) perpendicular to the rotation axis of the camshaft 18 is in contact with the cam 17, and the tappet 19 is slid on the other end of the tappet 19. An interlocking push rod 20 is connected. An intake rocker arm and an exhaust rocker arm 21 are swingably held at the upper part of the cylinder 8. One end of the rocker arm 21 is in contact with the intake and exhaust valves 12, and the other end is a push rod 20. These are covered with a cylinder head cover 22, and a rocker arm chamber 23 is formed by the cylinder head cover 22. The rocker arm chamber 23 corresponds to a valve operating chamber.

  An oil chamber 25 for storing oil 24 is provided in the crankcase 11 in a substantially L-shaped cross section, and the oil chamber 25 is separated by a crank chamber 16 and a partition wall 26. The oil chamber 25 is in the state shown in FIG. 2 and is located at the first oil chamber 25a located below the crank chamber 16 and on the side of the crank chamber 16 connected to the first oil chamber 25a (left side of the crank chamber 16 in FIG. 2). The second oil chamber 25b is formed to have a substantially L-shaped cross section. The partition wall 26 is formed with a communication portion that communicates from the crank chamber 16 to the oil chamber 25. The communication portion is provided so as to close the communication hole 27 that connects the crank chamber 16 and the oil chamber 25, and the first valve 28 that can communicate with the oil chamber 25 from the crank chamber 16 only in one direction. Is provided. The first valve 28 is configured to open and close due to pressure fluctuations in the crank chamber 16.

  The oil chamber 25 is provided with a first communication portion 29 that is located below the communication hole 27 and communicates with the communication hole 27. A first communication portion 29 is formed in the communication direction of the communication hole 27. A wall 29a is located. The first communication portion 29 has a second wall 29b connected to the outer portion of the partition wall 26, and an opening 29c of the first communication portion 29 is formed by the first wall 29a and the second wall 29b. .

  One end of a hollow first tube 30 (first connecting member) that can be freely bent is attached to the opening 29c, and a discharge port 31a is attached to the other end of the first tube 30. A weight 31 is provided. The weight 31 is attached to the other end of the first tube 30 by press fitting or the like. As shown in FIG. 2, the discharge port 31 a of the weight 31, which is the other end side of the first tube 30, is immersed in the oil 24 stored in the oil chamber 25. That is, during normal use in FIG. 2, the oil 24 is stored in the first oil chamber 25 a of the oil chamber 25, and the other end of the first tube 30 is positioned in the oil 24 by the weight of the weight 31. Yes. The weight 31 is positioned in the oil 24 in a state where it hits the inner wall of the lower wall forming the first oil chamber 25a. Note that the amount of oil 24 stored in the oil chamber 25 is the maximum amount that the suction port 33 does not enter the oil 24.

  In the oil chamber 25, a second communication portion 32 is provided adjacent to the first communication portion 29. The second communication part 32 is constituted by a third wall 32a and a first wall 29a of the first communication part 29, and a suction port 33 is formed by the first wall 29a and the third wall 32a. An opening 32b is also formed on the anti-suction port 33 side of the second communication portion 32, and one end of a second tube 34 (second connecting member) is attached to the opening 32b by press-fitting or the like. The other end of the second tube 34 is connected to the rocker arm chamber 23 and opens into the rocker arm chamber 23. The suction port 33 is located in the oil chamber 25 and above the upper surface of the oil 24. That is, in the normal position state shown in FIG. 2, the suction port 33 is provided at a position where it is not immersed in the oil 24. That is, the suction port 33 is located above the upper surface of the oil 24.

  The rocker arm chamber 23 and the crank chamber 16 are communicated by a passage 35 where the push rod 20 is located. The passage 35 includes a first passage 35a that communicates with the rocker arm chamber 23, and a second passage 35b that communicates with the crank chamber 16 via a second valve 36 that communicates with the first passage 35a and can communicate with only one direction. The The second valve 36 is provided between the crank chamber 16 and the second passage 35b, and is configured to be able to communicate with the crank chamber 16 only in one direction from the second passage 35b. Further, the second passage 35b is provided with a third valve 37 that can communicate with the third tube 38 from the second passage 35b. The second passage 35b includes the third valve 37 and the third valve unidirectionally. It leads to an air cleaner chamber (not shown) via a tube 38.

  Next, the oil lubrication structure of the engine 2 will be described in detail. The brush cutter 1 is normally used so that the reciprocating direction of the piston 9 is the vertical direction in the figure. When the brush cutter 1 is in the normal use state, it is in the state shown in FIG. 2, and this state is the initial state. When the engine 2 generates a spark by an ignition plug (not shown) facing the combustion chamber 8a and ignites the fuel in the combustion chamber 8a, the piston 9 descends due to the explosion, and the state shown in FIG. 3 is obtained. Since the crank chamber 16 is sealed, the volume of the crank chamber 16 is reduced by the lowering of the piston 19 and the pressure in the crank chamber 16 is increased. The first valve 28 is opened by the pressure difference between the oil chamber 25 and the crank chamber 16, and the first communication portion 29 and the crank chamber 16 communicate with each other. The gas (air) in the crank chamber 16 is sent to the first communicating portion 29 through the through hole 27 when the first valve 28 is opened as indicated by an arrow A in FIG. Since the first tube 30 is attached to the opening 29 c of the first communication chamber 29, the gas sent to the first communication portion 29 is sent to the oil chamber 25 through the first tube 30. Since the weight 31 is attached to the other end of the first tube 30, the other end of the first tube 30 is immersed in the oil 24 stored in the oil chamber 25. The gas sent through the first valve 28 and the first tube 30 is discharged from the discharge port 31 a of the weight 31 into the oil 24. The discharged gas becomes bubbles 39 in the oil 24, and the bubbles 24 repel on the upper surface of the oil 24, whereby the oil 24 becomes mist-like oil (oil mist) 24 a in the oil chamber 25.

  The pressure of the oil chamber 25 is increased by the gas discharged from the crank chamber 16 through the through hole 27, the first tube 30, and the weight 31 into the oil chamber 25. That is, since the crank chamber 16 and the oil chamber 25 communicate with each other through the first tube 30 or the like, the crank chamber 16 and the oil chamber 25 have the same pressure, so the pressure in the oil chamber 25 also increases. When the pressure in the oil chamber 25 rises above the pressure in the rocker arm chamber 23, the oil mist 24a together with the gas discharged into the oil chamber 25 flows into the suction port 33 of the second communication portion 32 as shown by the arrow B in FIG. Then, as shown by an arrow C in FIG. 3, the fluid is expelled to the rocker arm chamber 23 and the passage 35 through the second tube 34. The oil mist 24a discharged to the rocker arm chamber 23 and the passage 35 adheres to the rocker arm 21, the valve 12, and the like, so that the movable part composed of the rocker arm 21 and the like can be effectively lubricated.

  The gas and oil mist flowing into the rocker arm chamber 23 and the passage 35 flow through the first passage 35a to the second passage 35b. When the gas and oil mist flow to the second passage 35b, the passage 35 (the first passage 35a and the second passage 35b) and the oil chamber 25 communicate with each other, whereby the pressure of the second passage 35b increases. At this time, the crank chamber 16 and the second passage 35b communicate with each other through the first tube 30, the oil chamber 25, the second tube 34, and the first passage 35a. The pressure will be the same and the second valve 36 will not open. On the other hand, the second passage 35 b is connected to an air cleaner chamber (atmosphere) (not shown) via a third valve 37 and a third tube 38. Since the second passage 35b communicates with the oil chamber 25, when the pressure in the second passage 35b rises from the atmospheric pressure, a difference occurs in the pressure between the second passage 35b and the air cleaner chamber. Open and the gas is expelled into the air cleaner chamber as shown by arrow D in FIG.

  Further, the oil adhering to the drive part (movable part) such as the rocker arm 21 of the rocker arm chamber 23 is liquefied by increasing the amount of adhesion to the movable part, and is transmitted along the inner wall of the first passage 35a and the push rod 20. Thus, the first passage 35a passes through the first passage 35a and accumulates in the second passage 35b located below the first passage 35a. Since the second valve 36 is not opened by the above-described operation, oil can be accumulated in the second passage 35b.

  Thereafter, as shown in FIG. 4, when the piston 9 ascends from the state where the piston 9 in FIG. 3 is lowered, the pressure in the crank chamber 16 is reduced due to the increase in the volume of the crank chamber 16, whereby the first valve 28 is closed. When the pressure in the crank chamber 16 falls below the pressure in the second passage 35b, the second valve 36 opens due to the pressure difference between the crank chamber 16 and the second passage 35b, and the oil mist 24a is removed as shown by arrow E in FIG. The contained gas and the oil accumulated in the second passage 35 b are sucked into the crank chamber 16. As a result, the oil sucked into the crank chamber 16 adheres to the drive portions (movable portions) such as the gear 14 and the cam gear 15 in the crank chamber 16 so that the drive portion can be lubricated. At this time, the third valve 37 is in a closed state. Further, since the liquefied oil sucked into the crank chamber 16 together with the oil mist 24a can also be used for lubrication of the drive unit, lubrication can be performed effectively. That is, the liquefied oil sucked into the crank chamber 16 is scattered in the crank chamber 16 by hitting the rotating material of the cam gear 15 located below the second valve 36 in the figure, and therefore also to the gear 14 and the like. The oil adheres and the accumulated oil can be effectively used to effectively lubricate the drive unit. The oil liquefied in the crank chamber 16 returns to the crank chamber 16 due to the bottom of the crank chamber 16, that is, the partition wall 26 that partitions the oil chamber 16 and the oil chamber 25 is curved toward the through hole 37. After lubricating the gear 14 and the like, the oil is transferred to the bottom of the crank chamber 16 through the partition wall 26, and when the piston 9 descends again, the first valve 28 is opened to open the gas in the crank chamber 16. Is returned to the oil chamber 25 together.

  The brush cutter 1 as an embodiment of the engine tool of the present invention normally uses the reciprocating direction of the piston 9 as the vertical direction, as shown in FIGS. However, other engine tools, such as a chain saw, may be used with the chain saw body turned sideways or upside down, depending on the work, in addition to being used in the orientation shown in FIGS. . Therefore, an oil lubrication structure of the engine 2 when the engine 2 is used in a state other than the upright state will be described below.

  As shown in FIG. 5, the chain saw 50 includes an engine case 57 in which the engine 2 is disposed, a rear handle 51 that protrudes rearward (right side in the figure) from the engine case 57, and a substantially D-shaped rear handle 51. The front handle 52 that is connected to the engine case 57 and is substantially C-shaped so as to surround the engine case 57, the saw chain 55 that transmits the power of the engine 2, the flat guide bar 54 that guides the saw chain 54, and the front handle 52 It is mainly composed of a hand guard 53 provided on the front side (guide bar side) and above the engine case 57. The rear handle 51 and the front handle 52 are configured as a unit connected by a connecting portion (not shown). Further, the engine case 57 and the handle unit are connected by a vibration isolating member (not shown), specifically a coil spring or rubber, for suppressing vibration generated by driving the engine from being transmitted to the handle unit.

  As an operation of the chain saw 50, an operator starts the engine 2, holds the handles 51 and 52, and operates a throttle lever (not shown). By operating the lever, the power of the engine 2 is transmitted to the saw chain 55, and the saw chain 55 is guided by the guide bar 54 and rotated to perform the cutting operation.

  The direction of the engine 2 in FIG. 5 is a state in which the reciprocating direction of the piston 9 is the vertical direction in the drawing as shown in FIGS. 2 to 4. In the following, each state will be described with reference to FIGS. 6 to 8.

  6 is a cross-sectional view of the engine (guide) showing a state in which the engine 2 is tilted to the left (a state in which the engine 2 is tilted 90 degrees to the left in the figure from the upright state in FIG. 2). The cross section of the bar 55 in the longitudinal direction) shows a state in which the piston 9 is located at the top dead center in the reciprocating direction. In the case of the brush cutter 1 of FIG. 1, the state is inclined 90 degrees to the right from the state of FIG.

  In the state of FIG. 6, the oil 24 is accumulated in the second oil chamber 25 b of the oil chamber 25 located on the lower side of the engine 2. The first tube 30 is a flexible tube that can be bent, that is, a flexible tube, and a weight 31 is attached to the other end of the first tube 30. The weight 31 is positioned in the second oil chamber 25b positioned on the side. Since the oil 24 is accumulated in the second oil chamber 25 b located on the lower side of FIG. 6, the weight 31 is immersed in the oil 24 and the discharge port 31 a of the weight 31 is also immersed in the oil 24. Further, since the suction port 33 of the second communication portion 32 is located above the upper surface of the oil 24, the suction port 33 is not immersed in the oil 24 even in the inclined state of FIG. Is arranged. The amount of the oil 24 that can be stored in the oil chamber 25 is an amount that does not allow the suction port 33 to enter the oil 24. One end of the tube 30 is attached to the opening 29c of the first communication portion 29 by press-fitting or the like, and is configured not to be detached from the first communication portion 29.

  When the piston 9 reciprocates in this state, a mist-like oil 24a is produced in the same manner as in the above-described upright state, and each drive unit can be lubricated by the oil mist 24a due to pressure fluctuations in the crank chamber 16 and the like. it can. Specifically, it operates as follows.

  When the piston 9 descends (moves to the right in the figure) from the state of FIG. 6, the volume of the crank chamber 16 is compressed and the pressure rises. When the pressure in the crank chamber 16 rises higher than the pressure in the oil chamber 25, the first valve 28 is opened, and the gas (air) in the crank chamber 16 passes through the first pipe 30 and the discharge port 31a to the oil chamber. 25 (second oil chamber 25b). Since the oil 24 is stored in the second oil chamber 25b, bubbles are generated in the oil 24 by the air discharged from the discharge port 31a. The bubbles are bounced on the upper surface of the oil 24, whereby the oil 24 is misted. Since the crank chamber 16 and the oil chamber 25 communicate with each other through the first tube 30 or the like, the pressures in the crank chamber 16 and the oil chamber 25 are substantially equal, and the pressure in the oil chamber 25 is more than the pressure (atmosphere) in the rocker arm chamber 23. To rise. Due to the pressure difference between the rocker arm chamber 23 and the oil chamber 25, the air in the oil chamber 25 and the mist of oil mist pass through the suction port 33 and the second tube 34 to the rocker arm chamber 23 and the passage 35. be introduced. The oil mist that has entered the rocker arm chamber 23 and the passage 35 adheres to the push rod 20, the rocker arm 21, etc., so that the drive unit such as the rocker arm 21 can be lubricated. When the pressure in the passage 35 rises from the atmospheric pressure, the third valve 37 is opened, and the passage 35 and an air cleaner chamber (not shown) communicate with each other.

  When the piston 9 rises from the bottom dead center position, that is, the state in which the piston 9 is positioned on the right side of the cylinder 8 in FIG. 6 to the state in FIG. 6, the volume of the crank chamber 16 expands and the pressure becomes negative. Due to the pressure difference between the crank chamber 16, the oil chamber 25, and the passage 35, the first valve 28 and the third valve 37 are closed and the second valve 36 is opened. The oil mist introduced into the passage 35 is returned to the crank chamber 16 via the second valve 36.

  Here, the oil mist that has entered the rocker arm chamber 23, the passage 35, and the crank chamber 16 collides with the respective inner walls and the like to be liquefied, but in the state of FIG. 6, the liquefied oil has its own weight. Accordingly, the rocker arm chamber 23 and the crank chamber 16 are accumulated in the lower portion (the portion of each chamber located on the lower side in the drawing). Each drive part can be effectively lubricated by the oil accumulated in each room. Further, the oil accumulated in the lower portion of the crank chamber 16 is diffused by the rotation of the crank weight 14a and adheres to the gear 14, the cam gear 15 and the like, so that lubrication can be performed. In addition, the oil mist 24a returned to the crank chamber 16 through the second valve 36 without being liquefied adheres to the gear 14, the cam gear 15 and the like, and the oil mist 24a is further diffused by each gear. Therefore, the valve operating part (driving part) can be lubricated. The crank weight 14a rotates together with the gear 14 and counteracts vibrations caused by the reciprocating motion of the piston 9 by rotating in the opposite phase to the piston 9 in conjunction with the reciprocating motion of the piston 9.

  Normally, once the engine 2 is activated, the engine 9 enters an idling state in which the piston 9 reciprocates at a predetermined speed even when the throttle lever is not operated. That is, since the piston 9 always reciprocates after the engine is started, the first to third valves 28, 36, and 37 are repeatedly opened and closed. Accordingly, in the state shown in FIG. 6, the oil is accumulated in the crank chamber 16 and the rocker arm chamber 23. However, the accumulated oil is reduced by changing the state shown in FIG. It can be returned to the oil chamber 25.

  FIG. 7 shows a state where the engine 2 is inverted, and shows a state where the piston 9 is located at the top dead center (downward in the figure) in the reciprocating direction. In the case of the brush cutter 1 shown in FIG. 1, the state shown in FIG. 2 is turned upside down.

  In this state, the oil 24 in the oil chamber 25 is accumulated in the second oil chamber 25b with the inner wall on the cylinder 8 side of the second oil chamber 25b as the bottom surface. The first tube 30 is bent downward in the figure by the weight of the weight 30, and the discharge port 31 a is immersed in the oil 24. The amount of oil 24 that can be stored in the oil chamber 25 is such that the suction port 33 is not immersed in the oil 24, and the suction port 33 is not always immersed in the oil 24.

  As the piston 9 reciprocates in this state, a mist-like oil 24a is produced as in the state of the engine 2 described above, and each drive unit is lubricated by the oil mist 24a due to pressure fluctuations in the crank chamber 16 and the like. be able to.

  Here, the oil mist that has entered the rocker arm chamber 23, the passage 35, and the crank chamber 16 collides with the respective inner walls and the like to be liquefied. However, in the state of FIG. 7, the liquefied oil has its own weight. As a result, the rocker arm chamber 23 and the crank chamber 16 are accumulated in the lower portion (portion located on the lower side in the figure). The rocker arm 21 and the like can be effectively lubricated by the accumulated oil. In addition, the slidability of the piston 9 can be improved by the oil accumulated in the lower part of the crank chamber 16 (the second valve 36 side and the piston 9 side). Further, the oil mist 24a returned to the crank chamber 16 through the second valve 36 without being liquefied adheres to the gear 14, the cam gear 15 and the like, and the oil mist 24a is further diffused by each gear. Thus, the valve operating part (driving part) can be lubricated effectively.

  As described above, the engine 2 is idling when the throttle lever is not operated, and the first to third valves 28, 36, and 37 are repeatedly opened and closed. Accordingly, in the state shown in FIG. 7, the oil is accumulated in the crank chamber 16 and the rocker arm chamber 23. However, the oil is accumulated in each room by changing the state shown in FIG. The oil can be returned to the oil chamber 25.

  FIG. 8 shows a state in which the engine 2 is tilted to the right (the state in which the engine 2 is tilted 90 degrees from the upright state in FIG. 2 to the right in the drawing and the state in FIG. 6 is turned upside down). FIG. 6 is a cross-sectional view of the engine showing a state in which the piston 9 is located, and shows a state where the piston 9 is located at the top dead center in the reciprocating direction. In the case of the brush cutter 1 in FIG. 1, the state is inclined 90 degrees to the left from the state in FIG.

  In this state, the oil 24 in the oil chamber 25 is accumulated in the first oil chamber 25a. The first tube 30 is bent downward in the figure by the weight of the weight 30, and the discharge port 31 a is immersed in the oil 24. The amount of oil 24 that can be stored in the oil chamber 25 is such that the suction port 33 is not immersed in the oil 24, and the suction port 33 is not always immersed in the oil 24.

  As the piston 9 reciprocates in this state, a mist-like oil 24a is produced in the same manner as in the state of the engine 2 described above. ) Can be lubricated.

  Here, the oil mist that has entered the rocker arm chamber 23, the passage 35, and the crank chamber 16 collides with the respective inner walls and the like to be liquefied. However, in the state of FIG. 8, the liquefied oil has its own weight. As a result, the rocker arm chamber 23, the crank chamber 16, and the lower portion of the passage 35 (the portion located on the lower side in the figure) are accumulated. The oil accumulated in the lower side of the crank chamber 16 in the figure is diffused by the cam gear 15 to become a mist, adhere to the gear 14 and can be lubricated. Further, the oil mist 24a returned to the crank chamber 16 through the second valve 36 without being liquefied adheres to the gear 14, the cam gear 15 and the like, and the oil mist 24a is further diffused by each gear. Thus, the valve operating part (driving part) can be lubricated effectively. Further, the oil accumulated in the rocker arm chamber 23 may be accumulated in the second tube 34, but is returned to the oil chamber 25 by the pressure fluctuation in each chamber.

  As described above, the engine 2 is idling when the throttle lever is not operated, and the first to third valves 28, 36, and 37 are repeatedly opened and closed. Therefore, in the state of FIG. 8, oil accumulates in the crank chamber 16, the rocker arm chamber 23, and the passage 35. However, by changing the state of FIG. 8 to the upright state of FIG. The oil accumulated in the room can be returned to the oil chamber 25.

  In the state of FIGS. 6 to 8, the chain saw 50 and the like are hand-held tools, that is, machines that are operated while being held by the operator's hand, and therefore do not work for a long time in the state of FIGS. 6 to 8. 2 may be brought into the upright state in FIG. 2 for a short time during the operation, so that the oil accumulated outside the oil chamber 25 can be returned to the oil chamber 25 and the oil 24 in the oil chamber 25 is not lost. . Even if the oil 24 in the oil chamber 25 decreases, the discharge port 31a of the weight 31 is always located at the bottom of the oil chamber 25 regardless of the direction of the engine 2, so that the oil 24 is located at the position of the discharge port 31a. As long as it exists, oil mist can be generated and lubrication of the drive part (valve part) can be performed.

  According to the above-described embodiment, it is possible to effectively supply oil to the drive unit with a simple configuration by pressure fluctuation in the crank chamber or the like without using a pump or the like for lubricating oil.

  In particular, since the crank chamber and the oil chamber, and the oil chamber and the communication passage are communicated with each other by a one-way valve, the oil can be reliably lubricated with a simple configuration by utilizing the pressure fluctuation in each chamber.

  In addition, since one end of the tube connecting the crank chamber and the oil chamber is soaked in oil, the air discharged from the crank chamber to the oil chamber due to pressure fluctuations is released as bubbles in the oil, Oil mist can be easily generated by flipping on the top surface. Lubrication can be easily performed by supplying the oil mist to each drive unit by pressure fluctuation.

  In addition, because the tube connecting the crank chamber and the oil chamber is flexible (can be bent freely), the air in the crank chamber can be discharged into the oil regardless of the usage posture of the engine. The drive unit can be stably lubricated.

  In addition, by attaching a weight to one end of the tube connecting the crank chamber and oil chamber, the end of the tube can always be positioned in the oil regardless of the operating position of the engine. Oil mist can be produced.

  In addition, the oil chamber side end of the tube connecting the oil chamber and the rocker arm chamber is located at a position where it is not immersed in the oil, so that the misted oil can be reliably sent to the rocker arm chamber. The part can be lubricated.

  The working state of the engine 2 is not limited to the above-described state, and it may be inclined from the state of FIG. 2 to the front side or back side of the drawing, but the discharge port 31a is always in the oil 24. The drive part can always be effectively lubricated because of the soaking configuration. The present invention may be an engine tool, and can be applied to a brush cutter, a blower other than a chain saw, a hedge trimmer, and the like.

  Further, in the above-described embodiment, only one communicating portion for communicating the crank chamber 16 and the oil chamber 25 is provided. However, considering the use state of the engine 2, not only the bottom portion of the crank chamber 16 but also the crank chamber You may provide in 16 side walls (for example, the left wall of the crank chamber of FIG. 2). Furthermore, although the oil chamber 25 is L-shaped, an oil chamber may be provided so as to be positioned not only on the left and lower sides of the crank chamber 16 in FIG. good. In this case, a communication portion that communicates the crank chamber 16 and the oil chamber 25 may be provided on the right wall of the crank chamber 16. By providing the first valve 28 in each communication portion, it is possible to effectively lubricate the drive portion regardless of the use state of the engine 2 by utilizing the pressure fluctuation in the crank chamber 16 or the like.

  DESCRIPTION OF SYMBOLS 1 is a brush cutter, 2 is an engine, 3 is a long pipe, 4 is a handle, 5 is a cutter attachment part, 6 is a rotary cutter, 7 is a protective cover, 8 is a cylinder, 9 is a piston, 10 is a crankshaft, 11 Crankcase, 12 valve, 13 connecting rod, 14 gear, 15 cam gear, 16 crank chamber, 17 cam, 18 camshaft, 19 tappet, 20 push rod, 21 rocker arm, 22 cylinder Head cover, 23 is a rocker arm chamber, 24 is oil, 25 is an oil chamber, 26 is a partition wall, 27 is a communication hole, 28 is a first valve, 29 is a first communication portion, 30 is a first tube, and 31 is a weight , 32 is a second communication portion, 33 is a suction port, 34 is a second tube, 35 is a passage, 36 is a second valve, 37 is a third valve, and 38 is a third tube.

Claims (8)

In an engine tool having a crank chamber, an oil chamber in which oil communicates with the crank chamber via a communication portion, and a drive portion lubricated by the oil,
The communication portion is provided in a part of a partition wall that partitions the crank chamber and the oil chamber, a communication hole that connects the crank chamber and the oil chamber, and a communication hole that is provided in the communication hole from the crank chamber to the oil An engine tool comprising: a first valve that allows communication in one direction to the chamber; and a first connecting member having one end connected to the communication hole and the other end opened into the oil. A piston that reciprocates in a cylinder connected to a crankcase forming the crank chamber;
2. The oil mist is generated in the oil chamber by discharging the air in the crank chamber into the oil through the first connecting member in accordance with the reciprocation of the piston. Engine tools. The second communication portion includes a suction port that is located in the oil chamber and into which the oil mist enters, and a second connection member that communicates with the suction port and is connected to a drive portion that is driven according to the reciprocation of the piston. Have
3. The engine tool according to claim 2, wherein the oil mist is supplied to the driving unit from the suction port via the second connecting member.   The engine tool according to claim 3, wherein the second connecting member connects the oil chamber and the rocker arm chamber. A connection passage connecting the rocker arm chamber and the crank chamber;
A second valve that allows one-way communication from the connection passage to the crank chamber;
5. The engine tool according to claim 4, wherein the second valve opens and closes in response to reciprocation of the piston.   The engine tool according to any one of claims 3 to 5, wherein the suction port is located above an upper surface of the oil.   The engine tool according to any one of claims 1 to 6, wherein the first connecting member is a tube that can be bent freely.   The engine tool according to any one of claims 1 to 7, wherein a weight is provided at the other end of the first connecting member.

Images