JP2011047370A - Engine oil drain structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the discharge of oil in an engine without increasing a parts count and the work for discharging oil. <P>SOLUTION: An oil drain structure of an engine which keeps a lead valve between a crank chamber 34 and magnet chamber 18, allows the discharge of oil in both crank chamber 34 and magnet chamber 18 by a single drain bolt 61. The drain bolt 61 is screwed into a drain hole 62 coupled to both crank chamber 34 and magnet chamber 18. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an oil drain structure of an engine. In particular, the present invention relates to an oil drain structure in which a reed valve is disposed between a crank chamber and a magneto chamber, and oil flows from the crank chamber into the magneto chamber via the reed valve.

For example, various structures are conventionally used in an oil drain structure of an engine such as a motorcycle.
In the engine disclosed in Patent Document 1, a first oil reservoir chamber communicating with the crank chamber and a second oil reservoir chamber formed below the first oil reservoir chamber are configured via a reed valve. . A third oil sump chamber (oil pan) communicating with the second oil sump chamber is formed below the second oil sump chamber.

  A drain hole penetrating in the front-rear direction and communicating between the outside and the third oil reservoir chamber is formed at the lower end of the rear side wall portion that forms the second oil reservoir chamber and the third oil reservoir chamber. Yes. Under normal conditions, the drain hole is closed by screwing a drain bolt. When the oil is changed, the oil accumulated in the third oil reservoir chamber can be discharged to the outside by removing the drain bolt screwed into the drain hole.

JP 2007-291950 A

In the oil drain structure of the engine as described above, by removing the drain bolt, the oil accumulated in the second oil reservoir chamber and the third oil reservoir chamber on the downstream side from the reed valve can be discharged to the outside.
However, since the oil accumulated in the first oil reservoir is partitioned by the reed valve, it is difficult to discharge the oil accumulated in the first oil reservoir that communicates with the crank chamber even if the drain bolt is removed. There is a problem that there is.

  Although it is conceivable to further form a drain hole communicating with the first oil sump chamber or the crank chamber and separately provide a drain bolt for closing the drain hole, the number of parts is increased and the operation of discharging oil is performed. It becomes complicated.

  The present invention has been made in view of the above-described problems, and can easily discharge the oil in the engine without increasing the number of parts, and can easily perform the operation of discharging the oil. To.

An oil drain structure for an engine according to the present invention is an oil drain structure for an engine in which a reed valve is disposed between a crank chamber and a magneto chamber, and the oil in both the crank chamber and the magneto chamber is used as a single unit. It is possible to discharge with a drain bolt.
The drain bolt is screwed into a drain hole connected to both the crank chamber and the magneto chamber, and the reed valve is disposed on the rear side of the drain hole.
In addition, the opening of the drain hole of the drain bolt and the crank chamber is located above the opening of the drain hole of the drain bolt and the magnet chamber.
In addition, the opening of the drain hole of the drain bolt and the magneto chamber is formed on the inner peripheral surface of the drain hole.
The opening of the drain hole of the drain bolt and the crank chamber is formed at the top of the drain hole.

  According to the present invention, the oil in the engine can be easily discharged without increasing the number of parts, and the operation of discharging the oil can be easily performed.

1 is a left side view showing an overall configuration of a motorcycle according to an embodiment. It is a back perspective view of the engine concerning this embodiment. It is a left view of the engine which concerns on this embodiment. It is a right view of the engine which concerns on this embodiment. It is the side view which looked at the left crankcase concerning this embodiment from the inside. It is a side view around the magneto chamber concerning this embodiment. It is the II sectional view taken on the line of FIG. 3 which shows the structure around the oil pump which concerns on this embodiment. It is the II-II sectional view taken on the line of FIG. 5 which shows the oil drain structure which concerns on this embodiment.

Hereinafter, preferred embodiments of an oil drain structure for an engine according to the present invention will be described with reference to the drawings. Here, an oil drain structure of a motorcycle engine will be described as an example.
FIG. 1 is a left side view of a motorcycle having an oil drain structure for an engine according to this embodiment. First, the overall configuration of the motorcycle 100 will be described with reference to FIG. In each of the drawings including FIG. 1 in the following description, the front of the vehicle is indicated by an arrow Fr, the rear of the vehicle is indicated by an arrow Rr, and the lateral right side of the vehicle is indicated by an arrow R as necessary. The left side is indicated by an arrow L.

  The motorcycle 100 of FIG. 1 may typically be for so-called off-road use, and a steering head pipe 101 is disposed at the front upper part of the vehicle body, and a steering shaft (not shown) is disposed in the steering head pipe 101. Is pivotably inserted. A steering wheel 102 is attached to the upper end of the steering shaft, a front fork 103 is attached to the lower end of the steering shaft, and a front wheel 104 as a steering wheel is rotatable at the lower end of the front fork 103. Is pivotally supported.

  A pair of left and right main frames 105 extend obliquely downward from the steering head pipe 101 toward the rear of the vehicle body, and a down tube 106 extends substantially vertically downward. The down tube 106 branches right and left as a lower frame 106A in the vicinity of the lower portion, and the pair of lower frames 106A extends downward and then bends at a substantially right angle toward the rear of the vehicle body. The frame 107 is connected to each rear end portion of the main frame 105.

  In a space surrounded by the pair of left and right main frames 105, the down tube 106, the lower frame 106A, and the body frame 107, a water-cooled engine 10 as a drive source is mounted. A fuel tank 108 is disposed above the engine 10, and its fuel supply port is plugged by a cap 109. A seat 110 is disposed behind the fuel tank 108. A radiator 111 is disposed in front of the engine 10.

  A front end portion of the rear swing arm 112 is supported by a pivot shaft 113 so as to be able to swing up and down on a pair of left and right body frames 107 provided at a substantially lower center in the front-rear direction of the vehicle body. A rear wheel 114 as a drive wheel is rotatably supported at the rear end of the rear swing arm 112. The rear arm 112 is suspended from the vehicle body via a link mechanism 115 and a shock absorber 116 (rear wheel suspension device) connected thereto.

  A fuel pump unit is disposed in the fuel tank 108, and fuel is supplied to the engine 10 by the fuel pump unit. On the other hand, an air cleaner box 117 is disposed on the rear side of the shock absorber 116, and the air cleaner box 117 and the engine 10 are connected via an intake passage. Although not shown in FIG. 1, the intake passage is connected to an intake port provided in the cylinder head of the engine 10, and a throttle body is disposed as a part of the intake passage along the way. The throttle body is provided with a fuel injector, and fuel of a predetermined pressure is supplied from the fuel pump unit to the fuel injector.

  Next, the configuration of the engine 10 will be described. In this example, the engine 10 is a four-cycle single cylinder engine. FIG. 2 shows the overall configuration of the engine 10 in the present embodiment. In the engine 10, a crankcase 11 that rotatably accommodates and supports a crankshaft 12, a cylinder 13 that accommodates a piston in a vertically movable manner, a cylinder head 14 that accommodates a valve operating device, and a cylinder that covers the cylinder head 14. The head cover 15 is connected to the substantially vertical direction, that is, the cylinder axis of the cylinder block is set substantially in the vertical direction with respect to the axis of the crankshaft 12.

  Furthermore, it demonstrates with reference to FIGS. In the present embodiment, the crankcase 11 is divided into left and right parts along the split surface P as shown in FIG. A transmission chamber (or case) 16 is disposed on the rear side of the crank chamber 11 in the crank chamber 11 and a clutch chamber 17 is disposed on the right side, and a magnet chamber 18 is disposed on the left side. In the mission chamber 16, a plurality of mission gears for decelerating and transmitting the rotational output of the crankshaft 12 to the rear wheel 114 are arranged. A clutch device 19 is disposed in the clutch chamber 17 as shown in FIG. 4, and power transmission between the crankshaft 12 and the transmission gear is controlled to be connected / disconnected by operating the clutch lever of the handle 102 (FIG. 1). Yes. As shown in FIG. 3, a generator 20 including a stator coil 20 </ b> A and a magnet rotor 20 </ b> B is disposed in the magnet chamber 18.

  2 to 5, the clutch chamber 17 and the magneto chamber 18 are shown in a state in which the inside is exposed, but covers are respectively attached thereto. The mission chamber 16, the clutch chamber 17, and the magneto chamber 18 are substantially configured as a sealed space except for a communication portion with the engine 10 and other parts.

  Next, the intake / exhaust system of the engine 10 will be described. First, on the intake side, an intake passage is arranged between the air cleaner box 117 (FIG. 1) and the cylinder head 14 of the engine 10 as described above. This intake passage is connected to an intake port 21 (FIG. 2) provided in the cylinder head 14 of the engine 10, and a throttle body is disposed as a part of the intake passage in the middle thereof. The throttle body is provided with a fuel injector, and fuel of a predetermined pressure is supplied from the fuel tank 108 to the fuel injector.

  In addition, on the exhaust side of the intake / exhaust system, an exhaust pipe is connected to an exhaust port 22 (FIG. 4) provided in the cylinder head 14, and the exhaust gas after combustion generated by the engine 10 passes through the exhaust pipe. Exhausted. The exhaust pipe further extends to the rear of the engine 10 as an exhaust pipe, and a muffler (exhaust silencer) 118 (FIG. 1) is coupled. The exhaust is finally discharged from the muffler 118.

  Next, the cooling system of the engine 10 will be described. A radiator 111 is mounted in front of the engine 10. Although illustration is omitted, the cooling water cooled by the radiator 111 is guided to the water pump through a hose. The water pump feeds the cooling water to a water jacket formed on a cylinder block or the like of the engine 10 via a hose. Thereby, the engine 10 is cooled.

  Next, the valve train of the engine 10 will be described. The engine 10 of this embodiment is a so-called DOHC type. The cylinder head 14 has camshafts 27 and 28 on the intake side and the exhaust side, respectively (see FIG. 3). A cam chain 29 is mounted in a substantially vertical direction on the left side portion of the engine 10 (see FIG. 2), and the crankshaft 12 and the camshafts 27 and 28 are connected via the cam chain 29. In this case, a cam chain tunnel 30 is formed on the left side portion of the cylinder block including the cylinder 13 and the cylinder head 14 as indicated by a dotted line in FIG. The cam chain tunnel 30 is also arranged and configured substantially along the vertical direction.

  Next, in the lubrication system of the engine 10, as shown in FIG. 2, an oil pump 23 (scavenge pump) is disposed in the vicinity of the lower portion of the magneto chamber 18, and the oil accumulated in the magneto chamber 18 is sucked. The oil discharge side of the oil pump 23 is opened in the mission chamber 16 via the communication path 25b (see FIG. 5). That is, the oil pump 23 supplies the oil sucked up in the magneto chamber 18 to the mission chamber 16. To do. An oil pump 24 (feed pump) that is concentric with the oil pump 23 and has a rotating shaft that rotates synchronously is disposed in the mission chamber 16. As shown in FIG. 4, the oil pump 24 is arranged such that a part (right side portion) thereof is exposed near the lower portion of the clutch chamber 17, but oil is supplied to each part of the engine 10 via an oil passage 25 described later. To supply.

  As shown in FIG. 4, the oil discharge side of the oil pump 24 is connected to the oil passage 25. First, the oil is formed inside the clutch chamber cover (not shown) in the clutch chamber 17. The oil passage 25A is supplied to the oil filter chamber 26. Thereafter, the oil reaches the oil passage formed inside the crankcase 11 (right side) through the communication passage 25a, passes through the cylinder 13 (oil passage 25B), and further reaches the cylinder head 14 (oil passage 25C). . The oil is supplied from the oil passage 25C to a valve operating device or the like in the cylinder head 14, and the supplied oil is mainly dropped into the magneto chamber 18 and collected. Further, the oil is branched from, for example, the communication passage 25a and supplied to the journal portion of the crankshaft 12, and the supplied oil is mainly dropped into the crank chamber and collected.

  Further, a communication passage 38 is provided at the bottom of the crankcase 11 (both right and left sides) as shown in FIG. 5 (the crankcase 11 (left side) is viewed from the inside). Here, the communication passage 38 has a substantially rectangular passage section. A communication passage 38 formed in the right crankcase 11 is connected to the crank chamber 34. The oil that flows into or accumulates in the crank chamber 34 flows from the right side of the communication path 38 through a slope-shaped passage (not shown) formed inside the right crankcase 11. As shown in FIG. 6, the communication path 38 further opens into the magneto chamber 18 on the left side of the crankcase 11 (opening 39), and the communication path 38 and the magneto chamber 18 communicate with each other through the opening 39.

  In the magneto chamber 18, as shown in FIG. 6, a bulging portion 40 is formed by bulging the bottom portion downward. As shown in FIG. 6, the bulging part 40 (the bottom part) is lower than the opening part 39, and the bulging part 40 (the front part) is formed so as to expand forward from the opening part 39. As described above, the oil pump 23 is disposed near the lower portion of the magneto chamber 18 (FIG. 3), but the main body of the oil pump 23 is disposed appropriately above the bulging portion 40.

Further, a specific configuration of the oil pump 23 will be described with reference to FIG. 7 is a cross-sectional view taken along the line II in FIG. As shown in FIG. 7, the oil pump 23 includes an inner rotor 42 supported by the rotor shaft 41 and an outer rotor 43 disposed on the outer periphery thereof. The oil pump 23 is operated by the rotation of the rotor shaft 41. The casing of the oil pump 23 is formed by a part of the side wall of the crankcase 11 (left side), and the cover 44 is attached thereto. The cover 44 is fixed by a pair of bolts 45 and 45. An oil suction path 46 and an oil discharge path 47 are formed substantially vertically above and below the rotor shaft 41, and the oil pump 23 sucks oil through the oil suction path 46 and discharges it from the oil discharge path 47.

  An oil suction portion 48 is incidentally coupled to the lower portion of the oil suction path 46, and the oil suction portion 48 has a suction port 48a that opens downward. The oil suction part 48 is so-called covered with a soot, and is arranged in such a manner that it has an appropriate gap and its outer shape is accommodated approximately in line with the inner wall of the bulging part 40. In particular, the oil suction part 48 occupies a considerable part of the bulging part 40 in the longitudinal direction. As shown in FIG. 7, a strainer 49 is attached to the oil suction portion 48.

  Here, in the communication passage 38 extending in the left-right direction at the lower part of the crankcase 11, the reed valve 50 is arranged at the mating part (split surface P) of the left-right split crankcase 11 as shown in FIG. Established. The reed valve 50 has a substantially rectangular valve body 50 a, and the valve body 50 a has a size that substantially corresponds to the cross-sectional area of the communication passage 38. In this example, the valve body 50a is supported in a cantilever manner, that is, is supported in a cantilever manner by a support shaft 50b arranged in the vertical direction on the front side thereof, and the rear side is opened to the magneto chamber 18 to open the communication passage 38. Is to be opened. The valve body 50a is configured to open when the internal pressure of the crank chamber 34 changes, that is, when the internal pressure increases.

  The oil pump 24 arranged on the mission chamber 16 side has a rotor shaft 51 connected to the rotor shaft 41 of the oil pump 23 as shown in FIG. The rotor shaft 51 is configured to transmit power from the crankshaft 12 side through gears 52 and 53. Note that the rotor shaft 41 of the oil pump 23 is driven by the rotor shaft 51 of the oil pump 24. The oil pump 24 includes an inner rotor 54 pivotally supported on the rotor shaft 51 and an outer rotor 55 disposed on the outer periphery thereof. The oil pump 24 is operated by the rotation of the rotor shaft 51. The casing of the oil pump 24 is formed by a part of the side wall of the crankcase 11 (right side), and the cover 56 is attached thereto.

  As described above, the oil accumulated in the magneto chamber 18 in the oil lubrication system is sucked up by the oil pump 23, and the oil discharged from the oil pump 23 is then passed through the oil passage 25 through the mission chamber 16 and the oil pump 24. After passing, a part thereof is supplied to the valve operating device of the cylinder head 14, the cam chain 29, and the like. Further, a part is supplied to the journal portion of the crankshaft 12 and the like. Thereafter, the supplied oil falls into the magneto chamber 18 and the crank chamber 34 and is collected. The internal pressure of the crank chamber 34 changes in magnitude according to the vertical movement of the piston, and the internal pressure of the crank chamber 34 rises, so that the valve body 50a of the reed valve 50 is opened, whereby the crankcase 11 is connected via the communication path 38. Oil is circulated from the side to the magneto chamber 18.

Next, the oil drain structure of the engine 10 according to the present invention will be described.
When the engine is stopped, the oil that has lubricated each part drops after being supplied to each part, and accumulates in the mission chamber 16, the magneto chamber 18, and the crank chamber 34. The engine 10 of the present embodiment has an oil drain structure that can discharge oil accumulated in the mission chamber 16, the magneto chamber 18, and the crank chamber 34.

  First, as shown in FIGS. 2 to 5, a drain bolt 60 is screwed into the lower portion of the engine 10, specifically, the lower portion of the mission chamber 16. The drain bolt 60 is screwed into a drain hole (not shown) communicating the mission chamber 16 and the outside from the lower side of the mission chamber 16 along a substantially vertical direction, and closes this. On the other hand, oil accumulated in the mission chamber 16 can be discharged by removing the drain bolt 60 from the drain hole at the time of oil exchange or the like.

Next, as shown in FIGS. 2 to 5, a single drain bolt 61 is screwed into the lower portion of the engine 10, specifically, the lower portion of the boundary between the magneto chamber 18 and the crank chamber 34.
Here, the position where the drain bolt 61 is screwed will be described with reference to FIGS. 5, 6, and 8. 8 is a cross-sectional view taken along the line II-II shown in FIG. 5 when the crankcase 11 is coupled to the left and right (the cross-sectional view taken along the line III-III shown in FIG. 6 corresponds to this).

As shown in FIG. 8, a single drain hole 62 is formed along the vertical direction at the boundary between the magneto chamber 18 and the crank chamber 34. The drain hole 62 communicates both the magneto chamber 18 and the crank chamber 34 with the outside. Further, the inner peripheral surface of the drain hole 62 is threaded with a female screw for screwing the drain bolt 61. In FIG. 8, the crank chamber 34 appears to be divided up and down by the flange 66. This is because the line II-II is cut so as to pass through the flange 66 as shown in FIG. 5, and the upper and lower sides are the same space, that is, the crank chamber 34.
First, as shown in FIG. 6, the drain hole 62 and the magneto chamber 18 are side walls on the crank chamber 34 side of the magneto chamber 18 and communicate with each other via an opening 63 formed in the bottom of the bulging portion 40. Has been. The opening 63 is formed such that a part of the peripheral surface of the drain hole 62 is opened. As shown in FIG. 6, the opening 63 is formed in the lower front part of the communication path 38 that connects the crank chamber 34 and the magneto chamber 18.

Next, as shown in FIG. 5, the drain hole 62 and the crank chamber 34 are communicated with each other through an opening 64 formed in a side wall of the crank chamber 34 on the magnet chamber 18 side. The opening 64 is formed at the top of the drain hole 62 and communicates with a portion where a part of the crank chamber 34 formed in an arc shape is recessed. As shown in FIG. 5, the opening 64 is formed in the upper front portion of the communication path 38 that connects the crank chamber 34 and the magneto chamber 18. Therefore, the opening 64 of the crank chamber 34 is located above the opening 63 of the drain hole 62 and the magneto chamber 18 described above.
As described above, the drain hole 62 communicates with the magneto chamber 18 through the opening 63, communicates with the crank chamber 34 through the opening 64, and the lower portion opens to the outside. As shown in FIG. 8, the drain hole 62 is closed by screwing a drain bolt 61 having a length sufficient to close at least the opening 63 into the drain hole 62. Therefore, oil does not normally flow into the magneto chamber 18 from the crank chamber 34 through the drain hole 62 or be discharged from the drain hole 62 to the outside.

Next, the case where the oil in the magneto chamber 18 and the crank chamber 34 is discharged to the outside at the time of oil exchange or the like will be described.
First, since the internal pressure of the crank chamber 34 is not changed by stopping the engine 10, the operation of the valve body 50a of the reed valve 50 described above is also stopped, and the valve body 50a closes the communication path 38. . Therefore, the oil does not flow from the crank chamber 34 to the magneto chamber 18, and the oil is accumulated in the crank chamber 34 and the magneto chamber 18.

  Here, by removing the single drain bolt 61, the oil accumulated in the crank chamber 34 passes through the opening 64 and is discharged to the outside through the drain hole 62, and the oil accumulated in the magneto chamber 18 is also removed. The liquid is discharged from the drain hole 62 through the opening 63. As described above, even if the crank chamber 34 and the magneto chamber 18 are closed by the valve body 50a of the reed valve 50, the oil in the crank chamber 34 and the magneto chamber 18 can be obtained by removing the single drain bolt 61. Can be discharged to the outside. Therefore, there is no need to provide drain bolts in each of the crank chamber 34 and the magnet chamber 18, and the number of parts can be reduced. Moreover, since the single drain bolt 61 should just be removed, the efficiency of the operation | work which discharges | emits oil can be improved.

In the present embodiment, the position of the opening 64 formed in the crank chamber 34 is not the bottom of the crank chamber 34. That is, as described above, a slope-shaped flow path is formed inside the right crankcase 11 that is combined with the left crankcase shown in FIG. 5 so that oil near the opening 64 flows to the communication path 38. ing. That is, the bottom of the crank chamber 34 is a position close to the communication path 38.
Therefore, the oil that is lower than the height of the opening portion 64 of the crank chamber 34 and has accumulated between the communication passage 38 and the opening portion 64 of the crank chamber 34 may not be discharged to the outside. However, since the crank chamber 34, which has been in a negative pressure, becomes an atmospheric pressure when the drain bolt 61 is removed, the oil accumulated below the height of the opening 64 of the crank chamber 34 and up to the communication path 38 is reduced by its own weight. Then, the valve body 50 a of the reed valve 50 is opened and flows into the magneto chamber 18. Therefore, oil that could not be discharged to the outside from the opening 64 of the crank chamber 34 is also discharged to the outside through the opening 63 of the magneto chamber 18.

As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.
For example, in the above-described embodiment, the case where the opening 64 of the crank chamber 34 is formed at a position higher than the bottom is described. However, the present invention is not limited to this case, and the opening 64 is formed at the bottom of the crank chamber 34. May be. Specifically, as shown in FIG. 5, a space 65 formed in front of the communication passage 38 may be connected to the drain hole 62 as shown by a broken line in FIG. In this case, the oil accumulated in the bottom of the crank chamber 34 is configured such that the discharge path is connected to the slope-shaped flow path that flows from the position of the opening 64 to the communication path 38 at the bottom of the crank chamber 34. Can be discharged to the outside more reliably.
For example, in the above-described embodiment, the description has been made taking the engine using the motorcycle 100 as an example. However, the present invention is not limited to this, and may be applied to other engines.

DESCRIPTION OF SYMBOLS 10 Engine, 11 Crankcase, 12 Crankshaft, 13 Cylinder, 14 Cylinder head, 15 Cylinder head cover, 16 Mission chamber, 17 Clutch chamber, 18 Magnet chamber, 19 Clutch device, 20 Generator, 20A Stator coil, 20B Magnet rotor, 21 Intake port, 22 Exhaust port, 23 Oil pump (scavenge pump), 24 Oil pump (feed pump), 25 Oil passage, 26 Oil filter chamber, 27, 28 Cam shaft, 29 Cam chain, 30 Cam chain tunnel, 34 Crank chamber , 38 communication path, 39 opening, 40 bulge, 50 reed valve, 50a valve body, 60 drain bolt, 61 drain bolt, 62 drain hole, 63 opening, 6 4 openings, 100 motorcycle

Claims (5)

An engine oil drain structure in which a reed valve is disposed between a crank chamber and a magneto chamber,
An oil drain structure for an engine, wherein oil in both the crank chamber and the magneto chamber can be discharged by a single drain bolt. The drain bolt is screwed into drain holes connected to both the crank chamber and the magnet chamber,
2. The engine oil drain structure according to claim 1, wherein the reed valve is disposed on the rear side of the drain hole.   The opening of the drain hole of the drain bolt and the crank chamber is located above the opening of the drain hole of the drain bolt and the magneto chamber. Engine oil drain structure.   The engine oil drain according to any one of claims 1 to 3, wherein an opening between the drain hole of the drain bolt and the magneto chamber is formed on an inner peripheral surface of the drain hole. Construction.   5. The engine oil drain structure according to claim 1, wherein an opening portion between the drain hole of the drain bolt and the crank chamber is formed at a top portion of the drain hole. 6.

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