JP2009108835A - Lubricating device for multiple cylinder two-cycle engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating device for a multiple cylinder two-cycle engine capable of always securing a necessary quantity of lubricating oil evenly in a plurality of crank chambers 5 and of inhibiting oil temperature rise. <P>SOLUTION: An oil pump drive shaft 26 circulating lubricating oil supplied from an oil pump 20 is disposed in an oil pump drive mechanism chamber 22, lubricating oil supplied from the oil pump 20 is fed to the oil pump drive mechanism chamber 22 from a supply pipe 23, and lubricating oil is distributed and fed to each crank chamber 5 via a discharge pipe 24 from the oil pump drive mechanism chamber 22 by operation of check valves 34, 35 opening when pressure in the plurality of crank chambers 5 is negative pressure. An oil supply passage outlet part 32 is formed at a bottom part of the oil pump drive mechanism chamber 22. An oil discharge passage inlet part 33 is formed at a bottom part higher than the oil supply passage outlet part 32 of the oil pump drive mechanism chamber 22 and lower than an axial center of the oil pump drive shaft 26. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a lubrication apparatus for a multi-cylinder two-cycle engine that lubricates main components of a two-cycle engine having a plurality of cylinder chambers.

  2. Description of the Related Art Conventionally, in a two-cycle engine, scavenging, intake, explosion, and exhaust combustion cycles are performed to convert the linear motion of the crank piston into one rotation motion of the crankshaft to generate power.

  At this time, in the two-cycle engine, the crankshaft and the crank piston are connected via a connecting rod so that the linear motion of the crank piston is transmitted and converted into the rotational motion of the crank shaft.

  On the other hand, in such a two-cycle engine, the main components for generating the power described above are lubricated by a lubrication device.

At this time, for example, the lubrication apparatus is provided with a rotation proportional control mechanism that controls the discharge amount of the lubricating oil to the oil pump drive mechanism side at the discharge port of the oil pump (see, for example, Patent Document 1),
A lubrication path that extends from the oil tank and connects to the engine oil supply section is configured, and an oil pump for supplying oil to the oil supply section is arranged in the middle of the lubrication path, and is branched from the oil pump downstream side of the lubrication path. The return path connected to the upstream side of the oil pump is opened / closed by a solenoid valve, and the opening of the solenoid valve is controlled according to the engine operating status (for example, see Patent Document 2). .

  However, since it is unclear how the technique disclosed in Patent Document 1 distributes oil to a plurality of cylinder chambers (crank chambers), the amount of lubricating oil to a plurality of cylinder chambers (for example, two left and right chambers) Therefore, it is necessary to design without relying on the lubricating oil on the oil pump drive mechanism side, which causes a problem that the amount of lubricating oil consumption increases.

  In addition, the technique disclosed in Patent Document 2 uses a solenoid valve to supply appropriate lubricating oil, which causes a problem that the system becomes expensive.

  Therefore, a technique for supplying lubricating oil to a connecting rod through a shaft oil passage formed in a crankshaft is known in order to properly perform the distribution of lubricating oil to a plurality of cylinder chambers (crank chambers) without using a solenoid valve. (For example, see Patent Document 3).

  FIG. 11 shows a two-cycle engine 101 (disclosed in Patent Document 3) provided with such a lubrication device (only the main part is shown).

  In FIG. 11, the two-cycle engine 101 includes a crankshaft 103 disposed in the crankcase 102, a plurality of connecting rods 104 held at one end by the crankshaft 103, a drive gear 105 held by the crankshaft 103, A drive shaft 106 disposed in the crankcase 102 and orthogonal to the crankshaft 103, and a driven gear 107 held on the drive shaft 106 and meshed with the drive gear 105 are provided.

  A cylinder block 108 (only part of which is shown) is provided above the crankcase 102 in the figure, and the other end of the connecting rod 104 is provided in the crankcase chamber 109 formed by the cooperation of the crankcase 102 and the cylinder block 108. A crank piston (not shown) provided on the slidable portion is arranged so as to be displaceable. The drive shaft 106 has an axis extending in the depth direction perpendicular to the paper surface, and an oil pump (not shown) for circulating lubricating oil and a water pump (not shown) for circulating cooling water are provided near both ends thereof. (Not shown).

  An oil bath 110 is provided around the crankshaft 103 to lubricate the drive gear 105 and the driven gear 107.

  Lubricating oil is supplied to the oil bath 110 from the oil union unit 111. Further, a shaft oil passage 112 is formed in the crankshaft 103 in order to guide the lubricating oil supplied from the oil union unit 111 to the connecting rod 104 via the oil bath 110.

Furthermore, a connecting rod oil passage 113 (only one connecting rod 104 side is shown) that communicates with the shaft oil passage 112 is formed in the connecting rod 104 by dividing it into a plurality of divided and combined structures.
Japanese Patent Application Laid-Open No. 07-102931 JP 07-259525 A Special opening and closing No. 07-019016

  However, in the lubricating device for a multi-cylinder two-cycle engine configured as described above, it is necessary to divide the connecting rod 104 into a plurality of parts, so that it is difficult to ensure the strength of the connecting rod 104, and the connecting rod 104 becomes larger. In addition to the increase in weight, there has been a problem in that the cost of parts and assembly cost also rises.

  Further, since the oil bath 110 is filled with lubricating oil supplied to the shaft oil passage 112, the gears 105 and 107 are in the lubricating oil during rotation due to the engagement of the drive gear 105 and the driven gear 107. There has also been a problem that the oil temperature rises due to stirring during rotation.

  In view of the above circumstances, the present invention provides a lubricating device for a multi-cylinder two-cycle engine that can ensure the required amount of lubricating oil evenly in a plurality of crank chambers and that can suppress an increase in oil temperature. The purpose is to provide.

  A lubricating device for a multi-cylinder two-cycle engine according to the present invention includes a plurality of crank chambers formed adjacent to each other by a combined structure of a crankcase and a cylinder block, and an oil pump drive formed adjacent to the plurality of crank chambers. A mechanism chamber, an oil pump drive shaft disposed in the oil pump drive mechanism chamber for circulating the lubricant supplied from the oil pump, and the lubricant supplied from the oil pump to the oil pump drive mechanism chamber. Oil for distributing and supplying lubricating oil from the oil pump drive mechanism chamber to the plurality of crank chambers via an oil supply passage for supplying and a check valve that opens when the plurality of crank chambers are under negative pressure And an oil supply passage outlet portion of the oil supply passage is formed at a bottom portion of the oil pump drive mechanism chamber, and the oil discharge passage is formed. Wherein the oil discharge passage inlet of the passage is formed in a lower bottom portion than the axis of high and the oil pump drive shaft than the oil supply passage outlet.

  According to the lubricating device for a multi-cylinder two-cycle engine of the present invention, the lubricating oil fed from the oil pump to the oil pump drive mechanism chamber can be distributed to a plurality of adjacent crank chambers, and the distribution amount thereof Therefore, it is possible to reduce the amount of lubricating oil consumed and the amount of exhaust gas associated with the supply of the optimum amount of lubricating oil.

  The lubricating device for a multi-cylinder two-cycle engine of the present invention is an oil recovery system that recovers lubricating oil via a check valve that communicates with the plurality of crank chambers and opens when the plurality of crank chambers are at positive pressure. It is characterized by having a passage.

  According to the lubricating device of the multi-cylinder two-cycle engine of the present invention, the lubricating oil accumulated on the wall surface of the crank chamber can be positively recovered by utilizing the pressure fluctuation in the crank chamber, and thus the amount of lubricating oil consumed In addition, further reduction of exhaust gas can be realized.

  Furthermore, the lubricating device for a multi-cylinder two-cycle engine according to the present invention is characterized in that the oil discharge passage and the oil recovery passage are combined through the check valve.

  According to the lubricating device for a multi-cylinder two-cycle engine of the present invention, the common passage can supply and recover the lubricating oil when the crank chamber is under a negative pressure and when the crank chamber is under a positive pressure.

  In the lubricating device for a multi-cylinder two-cycle engine according to the present invention, the driven gear of the oil pump drive shaft is located between the oil discharge passage inlet and the oil supply passage outlet, and the lower end of the gear is the oil discharge. It is disposed at a position lower than the passage inlet and higher than the oil supply passage outlet.

  According to the lubricating device for a multi-cylinder two-cycle engine of the present invention, since the driven gear faces the stepped portion between the oil discharge passage inlet and the oil supply passage outlet, the entire driven gear is in the lubricating oil. There is no rotation.

  The lubricating device for a multi-cylinder two-cycle engine of the present invention can always ensure the required amount of lubricating oil evenly in a plurality of crank chambers, and can suppress an increase in oil temperature.

  Next, a lubricating device for a multi-cylinder two-cycle engine according to a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a side view of a two-cycle engine equipped with a lubrication device for a multi-cylinder two-cycle engine according to a first embodiment of the present invention. FIG. 2 is a lubrication device for a multi-cylinder two-cycle engine according to the first embodiment of the present invention. FIG. 3 is a longitudinal sectional view taken along line B-B of FIG. 3 in the two-cycle engine equipped with the. FIG. 3 is a diagram of FIG. 1 in the two-cycle engine equipped with the lubricating device for the multi-cylinder two-cycle engine according to the first embodiment of the present invention. FIG. 4 is a bottom view of a two-cycle engine equipped with a lubricating device for a multi-cylinder two-cycle engine according to the first embodiment of the present invention, and FIG. 5 is a first embodiment of the present invention. FIG. 6 is an enlarged cross-sectional view of the main part shown in FIG. 2 of the lubricating device for the multi-cylinder two-cycle engine according to FIG. 6, and FIG. 6 shows the main part shown in FIG. 3 of the lubricating device for the multi-cylinder two-cycle engine according to the first embodiment of the invention. Sectional enlarged view 7 and 8 are operation explanatory view of the lubricating apparatus for a multi-cylinder two-stroke engine according to the first embodiment of the present invention.

  1 to 4, a two-cycle engine 1 according to the first embodiment of the present invention includes a two-cycle engine body 4 including a crankcase 2 and a cylinder block 3, a crank chamber 5 and a cylinder of the crankcase 2. A scavenging port 7 straddling the combustion chamber 6 of the block 3, a first injector 8 for injecting fuel into the scavenging port 7, an intake pipe (throttle body) 9 communicating with the combustion chamber 6, and the intake pipe 9 are arranged. The throttle valve 10, the reed valve 11 disposed on the downstream side of the intake path of the intake pipe 9 from the throttle valve 10, and the fuel is injected into the intake pipe 9 by being disposed between the throttle valve 10 and the reed valve 11. A second injector 12 that performs combustion, an exhaust valve 14 that is disposed in an exhaust port 13 that communicates with the combustion chamber 6, and a combustion cycle according to the combustion cycle in the combustion chamber 6. A crank piston 15 that displaces inside the chamber 6, a crankshaft 16 that converts linear displacement of the crankpiston 15 into rotational motion, a connecting rod 17 that connects the crank piston 15 and the crankshaft 16, and a cylinder head cover 18 of the cylinder block 3. And a spark plug 19 whose front end faces the combustion chamber 6, an oil pump 20 for circulating lubricating oil, and a water pump 21 for circulating cooling water. In addition, in FIG. 1 thru | or FIG. 4, the said component may not be shown depending on the illustration form.

  Further, the two-cycle engine 1 is routed to the oil pump drive mechanism chamber 22 (see FIG. 3) formed close to the lower portion between the adjacent crank chambers 5 and the bottom surface of the crankcase 2 so that the oil pump 20 A supply pipe 23 serving as an oil supply passage for supplying the lubricating oil supplied from the oil pump driving mechanism chamber 22 and the lubricating oil supplied to the oil pump driving mechanism chamber 22 to the plurality of crank chambers 5. And a discharge pipe 24 (see FIG. 4) as an oil discharge passage for distributing and supplying the water.

  As shown in FIGS. 5 and 6, the oil pump drive mechanism chamber 22 penetrates near the center of the crankshaft 16, and the crankshaft 16 located in the oil pump drive mechanism chamber 22 has a drive gear 25. Is provided. The drive gear 25 meshes with a driven gear 27 provided on an oil pump drive shaft 26 orthogonal to the lower side of the crankshaft 16.

  On the other hand, the supply pipe 23 described above is communicated with the oil pump drive mechanism chamber 22 via a connection part 28 formed in the crankcase 2, and the discharge pipe 24 is connected to a connection part 29 and a connection part 30 formed in the crankcase 2. , 31 communicate with the oil pump drive mechanism chamber 22 and the crank chamber 5. An oil supply passage outlet 32 extending from the supply pipe 23 to the connecting portion 28 is formed at the bottom of the oil pump drive mechanism chamber 22. Furthermore, the inlet portion 33 of the oil discharge passage extending from the connecting portion 29 to the discharge pipe 24 is formed at the bottom that is higher than the outlet portion 32 of the oil pump drive mechanism chamber 22 and lower than the axis of the oil pump drive shaft 26. . The driven gear 27 is located between the inlet portion 33 and the outlet portion 32, and the lower end of the gear is disposed at a position lower than the inlet portion 33 and higher than the outlet portion 32.

  The discharge pipe 24 is connected to the connection portion 29 at a substantially central portion thereof, and is branched with the connection portion as a base point. A check valve 34 is opened at the end of the discharge pipe 24 near the connection portions 30 and 31 and is opened when the plurality of crank chambers 5 are negative pressure and closed when the plurality of crank chambers 5 are positive pressure. , 35 are provided.

  Hereinafter, the operation of the check valves 34 and 35 will be described with reference to FIGS.

  For example, as shown in FIG. 7, when the left crank chamber 5 is negative pressure (-), the oil pump 20, the supply pipe 23, the connection portion 28, the outlet portion 32, the oil pump drive mechanism chamber 22, and the inlet port. The lubricating oil fed in this order (see arrows J1 and J2) to the portion 33, the connection portion 29, and the discharge pipe 24 is opened in the check valve 34 and closed in the check valve 35, thereby the crank chamber on the left side in the figure. 5 (see arrow J3).

  On the contrary, as shown in FIG. 8, when the crank chamber 5 on the right side of the drawing is negative (-), the oil pump 20, the supply pipe 23, the connecting portion 28, the outlet portion 32, the oil pump drive mechanism chamber 22, Lubricating oil fed in this order (see arrows J1 and J2) to the inlet 33, the connecting portion 29, and the discharge pipe 24 is closed on the check valve 34 and opened on the check valve 35. It is fed to the chamber 5 (see arrow J4).

  Next, a lubricating device for a multi-cylinder two-cycle engine according to a second embodiment of the present invention will be described with reference to FIGS.

  FIG. 9 and FIG. 10 are operation explanatory views in the lubricating device of the multi-cylinder two-cycle engine according to the second embodiment of the present invention.

  In the two-cycle engine 1 according to the second embodiment, a valve body that opens when the plurality of crank chambers 5 are negative pressure and a plurality of crank chambers 5 are provided at the end portions of the exhaust pipe 24 near the connection portions 30 and 31. Check valves 34 ′ and 35 ′ having two passages provided with valve bodies that open when the pressure is positive are provided.

  As shown in FIG. 9, when the crank chamber 5 on the right side of the drawing is negative pressure (−) and the crank chamber 5 on the left side of the drawing is positive pressure (+), the check valve 34 ′ opens in the direction of arrow J5. The lubricating oil accumulated on the wall surface of the crank chamber 5 with the assistance of the crank chamber 5 on the left side of the figure is supplied together with the lubricating oil (see arrow J6) supplied from the oil pump drive mechanism chamber 22 in the right crank chamber 5. (See arrow J7) and sprayed as an air-fuel mixture.

  On the other hand, as shown in FIG. 10, when the left crank chamber 5 is negative pressure (−) and the right crank chamber 5 is positive pressure (+), the check valve 35 ′ is in the direction of arrow J8. By opening the valve, the left crank is received together with the lubricating oil (see arrow J9) supplied from the oil pump drive mechanism chamber 22 with the assistance of the crank chamber 5 on the right side of the figure and accumulated on the wall surface of the crank chamber 5 and the like. It is fed into the chamber 5 (see arrow J10) and sprayed as an air-fuel mixture.

  As a result, the discharge pipe 24 is also used as an oil recovery passage that actively recovers the lubricating oil accumulated on the wall surface of the crank chamber 5 by utilizing the pressure fluctuation in the crank chamber 5.

  In the second embodiment, the exhaust pipe 24 is also used as an oil recovery passage by using the bidirectional check valves 34 ′ and 35 ′. However, the check valve and the oil for recovering the lubricating oil in the crank chamber 5 are used. A recovery passage may be provided separately.

  Further, the oil recovery passage may be connected to the supply side to the oil pump drive mechanism chamber 22 such as the supply pipe 23 and the connection portion 28.

  Thus, in the lubricating device for the multi-cylinder two-cycle engine according to the first embodiment and the second embodiment of the present invention, the lubricating oil (arrow J1) supplied to the oil pump drive mechanism chamber 22 is discharged from the outlet. The portion exceeding the level difference between the portion 32 and the inlet portion 33 at a position higher than the outlet portion 32 is led to the discharge pipe 24 as overflow lubricating oil, and the overflow lubricating oil fed to the discharge pipe 24 Is connected to the check valve 34, 35 (34 ', 35') according to the internal pressure of the crank chamber 5 so that it can be distributed and supplied, whereby the crankcase 2 has a 180 degree phase (2 By utilizing the sine wave in the case of a cylinder), it is possible to alternately supply the same amount of overflow lubricating oil to the left and right crank chambers 5 in the figure.

  As a result, the amount of main lubricating oil used in the oil pump drive mechanism chamber 22 (not overflowing) can be set by the level difference between the outlet portion 32 and the inlet portion 33, and the amount of lubricating oil consumed can be reduced.

  Further, since the lubricating oil exceeding the level difference does not remain in the oil pump drive mechanism chamber 22, the drive gear 25 and the driven gear 27 are prevented from rotating in the lubricating oil, and the gears 25 and 27 are engaged with each other. Lubricating oil is not agitated during rotation, and the oil temperature does not rise.

  The partition structure between the oil pump drive mechanism chamber 22 and the crank chamber 5 employs a labyrinth seal structure in the illustrated embodiment. However, for example, the internal pressure of the crank chamber 5 such as an oil seal or a bearing with a seal is generally reduced. If it can interrupt | block, it will not specifically limit.

1 is a side view of a two-cycle engine equipped with a multi-cylinder two-cycle engine lubricating device according to a first embodiment of the present invention. It is a longitudinal cross-sectional view which follows the BB line of FIG. 3 in the 2 cycle engine which mounts the lubricating device of the multicylinder 2 cycle engine which concerns on 1st embodiment of this invention. It is a longitudinal cross-sectional view which follows the AA line of FIG. 1 in the 2 cycle engine which mounts the lubricating device of the multicylinder 2 cycle engine which concerns on 1st embodiment of this invention. 1 is a bottom view of a two-cycle engine equipped with a multi-cylinder two-cycle engine lubrication device according to a first embodiment of the present invention. It is an expanded sectional view of the principal part shown in Drawing 2 of the lubrication device of the multicylinder two cycle engine concerning a first embodiment of the present invention. FIG. 4 is an enlarged cross-sectional view of the main part shown in FIG. 3 of the lubricating device for a multi-cylinder two-cycle engine according to the first embodiment of the present invention. FIG. 5 is an operation explanatory diagram when one crank chamber is in a negative pressure in the lubricating device of the multi-cylinder two-cycle engine according to the first embodiment of the present invention. It is action explanatory drawing in the case where the other crank chamber is a negative pressure in the lubricating device of the multi-cylinder two-cycle engine which concerns on 1st embodiment of this invention. FIG. 10 is an operation explanatory diagram when one crank chamber is at a negative pressure and the other crank chamber is at a positive pressure in a lubricating device for a multi-cylinder two-cycle engine according to a second embodiment of the present invention. FIG. 10 is an operation explanatory diagram when the other crank chamber is negative pressure and one crank chamber is positive pressure in the lubricating device of the multi-cylinder two-cycle engine according to the second embodiment of the present invention. It is sectional drawing of the principal part of the lubrication apparatus of the conventional multicylinder 2 cycle engine.

Explanation of symbols

5 ... Crank chamber 20 ... Oil pump 22 ... Oil pump drive mechanism chamber 23 ... Supply pipe (oil supply passage)
24 ... Drain pipe (oil discharge passage)
26 ... Oil pump drive shaft 32 ... Outlet (oil supply passage outlet)
33 ... Inlet part (oil discharge passage inlet part)
34, 34 '... Check valve 35, 35' ... Check valve

Claims (4)

A plurality of crank chambers formed adjacent to each other by a combined structure of the crankcase and the cylinder block, an oil pump drive mechanism chamber formed close to the plurality of crank chambers, and the oil pump drive mechanism chamber. An oil pump drive shaft for circulating the lubricant supplied from the oil pump, an oil supply passage for supplying the lubricant supplied from the oil pump to the oil pump drive mechanism chamber, and the plurality of cranks An oil discharge passage for distributing and supplying lubricating oil from the oil pump drive mechanism chamber to the plurality of crank chambers via a check valve that opens when the chamber is under negative pressure,
An oil supply passage outlet portion of the oil supply passage is formed at a bottom portion of the oil pump drive mechanism chamber, an oil discharge passage inlet portion of the oil discharge passage is higher than the oil supply passage outlet portion, and the oil pump drive shaft A lubricating device for a multi-cylinder two-cycle engine, wherein the lubricating device is formed at a bottom lower than an axis.   2. An oil recovery passage for recovering lubricating oil via a check valve that communicates with the plurality of crank chambers and opens when the plurality of crank chambers are at positive pressure. Lubricator for multi-cylinder 2-cycle engines.   The lubricating device for a multi-cylinder two-cycle engine according to claim 2, wherein the oil discharge passage and the oil recovery passage are also used via the check valve.   A driven gear of the oil pump drive shaft is located between the oil discharge passage inlet and the oil supply passage outlet, and a lower end of the gear is lower than the oil discharge passage inlet and lower than the oil supply passage outlet. The lubricating device for a multi-cylinder two-cycle engine according to any one of claims 1 to 3, wherein the lubricating device is arranged at a high position.

Images