JP2003262112A - Lubricating device for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating device for an engine capable of avoiding occurrence of an air lock condition without enlarging an oil pump more than necessary. <P>SOLUTION: This lubricating device 38 for an engine 6 pressure-feeds a lubricating oil in an oil pan 39 to each part of an engine 6 through a lubrication route using an oil pump 41 driven by a crankshaft. The oil pump 41 is arranged higher than the oil level 46 of the lubricating oil in stopping the engine 6. A part of the lubrication route 71 connected with a downstream side of the oil pump 41 is arranged higher than the oil pump 41, and an opening to the interior space of the engine 6 is formed at the part of the lubrication route 71. The directly downstream side of an exhaust port 55 of the oil pump 41 and the directly upstream side of the opening are communicated each other through a communication passage 78 having a passage cross-sectional area thinner than the lubrication route 71 and extended upward. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an engine lubricating device.

[0002]

2. Description of the Related Art Since an engine has many sliding parts and rotating parts inside thereof, a lubricating device is used to supply lubricating oil to each part, and the function of the lubricating oil reduces the frictional resistance of each part. It is designed to fully exert its functions.

A typical lubricating oil path of a lubrication device for a four-cycle engine is the inside of the engine where the lubricating oil stored in an oil pan integrally or separately provided under the crankcase of the engine is sucked up by an oil pump. It is designed to send pressure to each lubrication part.

Lubricating oil that lubricates each lubricating portion in the engine is configured to be naturally dropped or returned to the oil pan through an oil drop passage or the like.

[0005]

However, after the engine is stopped for a while, or after the lubricating oil is replaced, the lubricating oil accumulated in the oil pump flows out into the oil pan due to gravity and is replaced with air. I will end up. As a result, when the engine is restarted after the above-mentioned conditions, the oil pump creates an airlock condition due to the passage resistance from the outlet of the oil pump to the closest open end, and the lubricating oil is pumped up until the engine reaches a certain speed or higher. It becomes impossible to supply lubricating oil to each part of the engine in the initial state after starting the engine.

Therefore, for example, Japanese Patent Laid-Open No. 10-1963
As disclosed in Japanese Patent Laid-Open No. 38-38, an orifice hole for opening the inside of the lubricating oil supply passage to the atmosphere is provided in a portion of the lubricating oil supply passage extending from the oil pump relatively close to the oil pump, and the lubricating oil supply including the inside of the oil pump at the time of engine start There is a structure in which the air in the passage is discharged from the orifice hole.

However, in the structure described in the above-mentioned publication, when the engine speed increases and the oil pressure and oil temperature of the lubricating oil discharged from the oil pump rise, the lubricating oil flows out from the orifice hole and reaches the downstream side of the orifice hole. There arises a problem that the oil pressure (oil amount) in the lubricating oil supply passage decreases. Therefore, it is necessary to set the discharge capacity of the oil pump according to the maximum amount of lubricating oil outflow, and the oil pump becomes unnecessarily large or the lubricating oil is discharged more than necessary at low engine speed. There is such a problem.

The present invention has been made in view of the above circumstances, and an object thereof is to provide an engine lubrication device capable of avoiding the occurrence of an airlock state without increasing the size of the oil pump more than necessary. .

[0009]

In order to solve the above-mentioned problems, a lubricating system for an engine according to the present invention has the following features.
As described above, the lubricating oil in the oil pan is pressure-fed to each part of the engine through the lubrication path by using the oil pump driven by the crankshaft, and the oil pump is used for the lubricating oil when the engine is stopped. In the engine lubrication device arranged above the surface, a part of the lubrication path connected to the downstream side of the oil pump is arranged above the oil pump, and a part of the lubrication path is connected to the internal space of the engine. Is provided, and the downstream side of the discharge port of the oil pump and the upstream side of the opening are communicated with each other by a communication passage extending upward with a cross-sectional area narrower than the lubrication route. Is.

In order to solve the above-mentioned problem, as described in claim 2, the opening to the internal space of the engine arranged above the oil pump is lubricated and cooled around the piston. This is a lubricating oil injection hole.

Further, in order to solve the above-mentioned problems,
As described in claim 3, the casing forming the oil pump is formed by facing a plurality of members,
The communication passage is formed on the mating surface of these members.

Further, in order to solve the above-mentioned problems, as described in claim 4, the communication passage is formed in a straight line in a substantially vertical direction.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a right side view showing an example of a motorcycle to which the present invention is applied. As shown in FIG. 1, the motorcycle 1 has an underbone type vehicle body frame (not shown), and a head pipe (not shown) provided on a front head portion thereof supports a front wheel 4 together with a handle bar 2 and a front fender 3. The front fork 5 is pivotally attached to the left and right so as to be steerable.

An engine 6 is mounted on the lower center of the vehicle body. Swing arm (not shown) from this engine 6
Further, the chain case 8 is extended rearward, and the rear wheel 9 as a drive wheel is pivotally supported by the rear portion of these. Further, an operation seat 10 is provided above the chain case 8, and the engine 6 is provided in the lower front part of the operation seat 10.
A leg shield 11 is arranged to cover the upper part and the left and right of the.

FIG. 2 shows the crankcase 12 of the engine 6.
FIG. 4 is a right side view (described later), showing a state in which a clutch cover 13 (described later) is removed. Further, FIG. 3 shows I of FIG.
FIG. 2 is a plan sectional view of the engine 6 including a sectional view taken along line II-III. As shown in FIGS. 1, 2 and 3, in the engine 6, for example, one cylinder assembly 16 composed of a cylinder head 14 and a cylinder block 15 in order from the front is substantially horizontal to the front part of the engine case 17. In the form, it is a single-cylinder engine that is mounted in a state that it is inclined slightly upward from the horizontal.

The engine case 17 is mainly divided into left and right crankcases 12 which are divided in the width direction of the vehicle, and a clutch cover 13 arranged on the right side surface of the crankcase 12.
And a generator cover 18 arranged on the left side surface of the crankcase 12. The clutch cover 13 and the generator cover 18 respectively project outward in the vehicle width direction.

Further, the engine 6 uses a single camshaft 20 having a cam 19 for opening and closing intake / exhaust valves (not shown) inside the cylinder head 14 to open and close each valve. (SO
It is a four-cycle engine equipped with a (HC) type valve mechanism 21.

Below the cylinder head 14, an exhaust pipe 22 and a muffler 2 which constitute an engine exhaust system are provided.
3 are connected. Further, a carburetor (not shown) constituting an engine intake system is connected to the upper portion of the cylinder assembly 16, and an air cleaner (not shown) is connected to the upstream side of the carburetor.

A crankshaft 24 is arranged in the crank chamber at a right angle to the width direction of the vehicle, that is, the traveling direction of the vehicle. Further, a cylinder bore 26 for accommodating the piston 25 is formed inside the cylinder block 15, and a combustion chamber 27 which is aligned with the cylinder bore 26 is formed in the cylinder head 14, and the combustion chamber 27 faces the combustion chamber 27 from the outside. The spark plug 28 is inserted.

A large end 30a of a connecting rod 30 is attached to a crankpin 29 located at the substantially central portion of the crankshaft 24.
The piston 25 is connected to the small end portion 30b of the connecting rod 30 via the piston pin 31.
The piston 25 reciprocates in the cylinder bore 26 in the axial direction, and the reciprocating stroke is the connecting rod 30.
Is transmitted to the crankshaft 24 via the shaft to rotate the crankshaft 24. A centrifugal automatic clutch mechanism 32, for example, is provided at one end of the crankshaft 24, which is the right end in this embodiment.

On the other hand, on the left side surface of the crankcase 12, a generator chamber 33 separated from the crankcase 12 is formed. The left end of the crankshaft 24 projects into the generator chamber 33, and the generator 34 is provided at this protruding end. The generator chamber 33 is covered with the generator cover 18, and the generator 3 of the crankshaft 24 is covered.
A cam drive gear 35 is provided on the inner side of 4.

A cam sprocket 36 is provided at one end of the cam shaft 20 arranged on the cylinder head 14, and the cam sprocket 36 is operatively connected to a cam drive gear 35 via a cam chain 37 to connect the crank shaft 24 with the cam drive gear 35. The rotation is transmitted to the camshaft 20 via the cam chain 37, so that the valve mechanism 21 operates.

By the way, the engine 6 according to the present invention supplies the lubricating oil 40 to the sliding parts and rotating parts inside thereof, and the frictional resistance of each part is reduced by the function of the lubricating oil 40, so that the function of the engine 6 is fully exhibited. A lubrication device 38 is provided.

FIG. 4 is a sectional view taken along line IV-IV in FIG. Further, FIG. 5 is a system diagram of the lubricating device 38. In the following description, the positional relationship of each member is the position when the engine 6 is mounted on the vehicle. As shown in FIGS. 2 to 5, an oil pan 39 for storing the lubricating oil 40 is provided below the crankcase 12 of the engine 6 integrally with or separately from the crankcase 12.

On the right side surface of the crankcase 12, for example, an oil pump 41 for sucking up the lubricating oil 40 in the oil pan 39 and pumping it to the lubricating parts in the engine 6 is provided. The oil pump 41 is, for example, a well-known trochoid pump, and is formed in the casing 42 of the rotor chamber 4.
An inner rotor 44 and an outer rotor 45 are provided in the unit 3. Further, the lower end of the rotor chamber 43 is arranged at a position equal to or higher than the oil surface 46 of the lubricating oil 40 in the oil pan 39 when the engine 6 is stopped.

The casing 42 is formed by, for example, two plate-shaped components, in the present embodiment, an inner plate 47 and an outer plate 48 facing each other in the axial direction of the crankshaft 24. For example, the outer plate 4
8, the inner chamber 47 is formed with a rotor chamber 43 inside to accommodate the inner rotor 44 and the outer rotor 45, and the casing 42 is mounted on the right side surface of the crankcase 12 by a plurality of mounting bolts 49a to 49c. Fixed to.

One end of a pump shaft 50 is rotatably connected to the inner rotor 44 in the rotor chamber 43. The pump shaft 50 is arranged in parallel with the crankshaft 24, a pump driven gear 51 is provided at an end of the crankcase 12 side, and the pump driven gear 51 is operated by a pump drive gear 52 provided on the crankshaft 24. Connect and crankshaft 2
The oil pump 41 is driven by the rotation of the oil pump 4.

From the suction port 53 of the rotor chamber 43, a suction passage 54 is formed, for example, toward the rear lower side of the outer plate 48.
Is formed inside the mating surface side with the inner plate 47. Further, from the discharge port 55 of the rotor chamber 43, a discharge passage 56 is formed, for example, toward the front lower side inside the mating surface side of the outer plate 48 with the inner plate 47.

On the other hand, in the crankcase 12, oil pumping passages 57 and 58, which are lubrication paths, are formed, for example, extending upward from the oil pan 39 and then extending toward the right side surface of the crankcase 12. A strainer 59 is provided at the upstream ends of these oil pumping passages 57, 58 and is always located in the lubricating oil 40 in the oil pan 39. In addition, the oil pumping passage 57,
The downstream end of 58 is opened to face the right side surface of the crankcase 12, and the suction passage 54 of the oil pump 41 is connected to the opening 60.

On the other hand, a main gallery 61, which is another lubrication path, is formed in the crankcase 12, and another lubrication path is provided from the main gallery 61 toward the sliding surfaces of the crankshaft 24 and the camshaft 20, for example. The oil supply paths 62 and 63 are formed by branching. Further, the upstream end of the main gallery 61 is opened to face the right side surface of the crankcase 12, and the oil pump 4 is inserted into the opening 64.
One discharge passage 56 is connected.

Further, the main gallery 61 before being branched into the oil supply passages 62 and 63 is provided with an oil filter 65 for filtering impurities and the like in the lubricating oil 40, and a relief from the upstream side of the oil filter 65. The passage 66 is branched to extend toward the oil pan 39, and a relief valve 67 is provided in the relief passage 66 to control the hydraulic pressure in the main gallery 61 upstream of the oil filter 65 (see FIG. 5). ). In addition,
The lubricating oil 40 that lubricates the sliding surfaces of the crankshaft 24 and the camshaft 20 is returned to the oil pan 39 by spontaneously dropping in the internal space of the engine 6 or via an oil drop passage (not shown) or the like. Is configured as follows.

A piston jet 6 for supplying lubricating oil 40 around the piston 25 in the crankcase 12
8,69 are provided. Engine 6 applied to the present invention
For example, as shown in FIG. 2, two piston jets 68 and 69 separated in the vertical direction are connected to the crankshaft 2
Prepared above 4. The piston jets 68 and 69 are provided with injection holes 72 and 73 which are openings to the internal space of the engine 6 and which are directed to the inside of the cylinder bore 26 at the downstream ends of jet passages 70 and 71 which are other lubrication paths. The passages 70 and 71 are connected to oil supply passages 74 and 75 which are other lubrication passages branched from the main gallery 61.

Further, the upper and lower jet passages 70, 71 are located at positions higher than the oil pump 41, respectively, from the right side surface of the crankcase 12 orthogonal to this surface.
The jet passage 70 on the upper side is bored toward the lower end of the cylinder bore 26, and the opening 76 is closed by a mounting bolt 49a for fixing the casing 42 of the oil pump 41 to the crankcase 12 (the mounting bolt 49).
a also serves as a blind stopper).

The opening 77 of the lower jet passage 71 is closed by the casing 42, in this embodiment, the surface of the inner plate 47 on the crankcase 12 side. That is, the casing 42 of the oil pump 41
Extends from below the crankshaft 24 to above.

In the discharge passage 56 formed in the casing 42 of the oil pump 41, the point closest to the rotor chamber 43,
That is, a communication passage 78 is formed immediately downstream of the discharge port 55 toward the side of the opening 77 that is immediately upstream of the lower jet passage 71 located above the discharge port 55. The communication passage 78 is formed, for example, in the shape of a groove extending linearly in the substantially vertical direction inside the mating surface side of the outer plate 48 with the inner plate 47, and the downstream end of the communication passage 78 and the opening 77 of the jet passage 71. A communication hole 79 that communicates both 77 and 78 is formed in the inner plate 47 located between and. The communication passage 78 includes a main gallery 61 and oil supply passages 62, 63, 7 that form a lubrication passage.
4, 75 and the jet passages 70, 71 are set to have a smaller passage cross-sectional area.

Next, the operation of this embodiment will be described.

The engine 6 starts and the crankshaft 2
When 4 rotates, the crankshaft 24 drives the oil pump 41. When the oil pump 41 operates, the lubricating oil 40 in the oil pan 39 is pressure-fed to each part in the engine 6 through the lubricating path.

Specifically, the lubricating oil 40 in the oil pan 39 passes from the oil pumping passages 57 and 58 to the suction passage 54 in the casing 42, and then from the suction port 53 to the rotor chamber 4.
3 and is pressurized by the inner rotor 44 and discharged from the discharge port 55 to the discharge passage 56. Discharge passage 56
Lubricating oil 40 discharged to the main gallery 61 is filtered by an oil filter 65 on the way, and a part of the lubricating oil 40 is pressure-fed toward the sliding surfaces of the crankshaft 24 and the camshaft 20 through the oil supply passages 62 and 63. After the sliding surface is lubricated, it is naturally dropped in the internal space of the engine 6 and returned to the oil pan 39.

The remaining lubricating oil 40 filtered by the oil filter 65 is jetted from the oil supply passages 74, 75 through the jet passages 70, 71, and from the injection holes 72, 73 around the piston 25. . The injected lubricating oil 40 lubricates the sliding surface between the piston 25 and the cylinder bore 26 and the sliding surface between the small end portion 30b of the connecting rod 30 and the piston pin 31, and the piston 2
The area around 5 is cooled, and, for example, the internal space of the engine 6 is naturally dropped and returned to the oil pan 39.

By the way, after the engine 6 is stopped and left for a while, or after the lubricating oil 40 is replaced, the oil pump 4
The lubricating oil 40 accumulated in 1 flows out to the oil pan 39 due to gravity and is replaced with air. When the engine 6 is restarted in such a state, conventionally, the opening closest to the discharge port 55 of the oil pump 41 is opened. Due to the passage resistance to the end, the oil pump 41 generates an air lock state, and the lubricating oil 40 cannot be pumped up until the engine 6 reaches a certain number of revolutions or more. In the initial state after the engine 6 is started, the lubricating oil 40 is applied to each part of the engine 6. Cannot be supplied.

In the present invention, the communication passage 78 is formed immediately downstream of the discharge port 55 toward the jet passage 71 having the injection hole 73 for the lubricating oil 40. Therefore, when the engine 6 is restarted, the inside of the oil pump 41 is reduced. The air is quickly discharged to avoid the airlock condition. Since the jet passage 71 originally constitutes a part of the lubrication passage, the jet passage 71 and the communication passage 78 form a closed circuit after the air is discharged. As a result, even if the rotation speed of the engine 6 increases after the engine 6 is started and the oil pressure and the oil temperature of the lubricating oil 40 discharged from the oil pump 41 increase, the lubricating oil 4
0 does not flow out to the outside and prevents a decrease in the oil pressure in the lubrication path.

Further, since it is possible to prevent the oil pressure in the lubrication path from decreasing, it is not necessary to unnecessarily increase the discharge capacity of the oil pump 41, and the oil pump 41 becomes larger than necessary or when the engine 6 rotates at a low speed. The problem that the lubricating oil 40 is discharged more than necessary does not occur.

Further, the discharge of the air in the oil pump 41 is suppressed by the lubricating oil 4 arranged above the oil pump 41.
Since it is performed from the injection hole 73 of 0, the air is easily released, and even if some air is mixed in the lubricating oil 40 injected from the injection hole 73 after the engine 6 is started, the cooling efficiency around the piston 25 is not reduced. Absent.

Furthermore, a casing 42 constituting the oil pump 41 is formed by facing a plurality of constituent members 47, 48, and a communication passage 78 is formed between these constituent members 4.
Since it is formed on the mating surface of 7, 48, the connecting passage 7
The rigidity of No. 8 can be secured, the communication passage 78 can be secured without increasing the number of parts, and an increase in weight and occupied space can be suppressed.

Since the communication passage 78 is formed in a straight line in the substantially vertical direction, air can be discharged without delay, and the shape of the communication passage 78 can be simplified to facilitate the formation. In the above-described embodiment, the communication passage 7
Although the example in which 8 is set to have a path cross-sectional area narrower than the lubrication path is shown, it is not always necessary to make it thin over the entire length of the communication passage 78.

By the way, in the conventional crankcase, the inertial force and the weight of the oil pump are received in the lower part of the crankshaft, so that the wall thickness of the crankcase is inevitably increased and the weight is increased. By extending the casing 42 of the pump 41 to the jet passages 70, 71 above the crankshaft 24, the rigidity of the crankcase 12 does not decrease even if the wall thickness of the crankcase 12 is reduced.

In the above-described embodiment, the opening 76 of the upper jet passage 70 is closed with the mounting bolt 49a for fixing the casing 42 of the oil pump 41 to the crankcase 12, and the opening of the lower jet passage 71 is closed. 7
Although an example is shown in which 7 is closed by the casing 42 and a communication hole 79 that connects the downstream end of the communication passage 78 and the opening 77 of the jet passage 71 is bored at this portion, although not shown in detail in the drawings, The mounting bolt having the downstream end extending to the side of the opening of the upper jet passage and fixing the casing of the oil pump to the crankcase may be a union bolt having a communication passage formed therein.

Further, the casing 4 of the oil pump 41
2 is an inner plate 47 and an outer plate 48 in advance
May be fixed to each other after being fixed to each other, or may be fastened together when the inner plate 47 and the outer plate 48 are mounted to the crank case 12.

The casing 42 having the above-described structure can be easily retrofitted to a conventional engine and the same effect can be obtained.

[0051]

As described above, according to the engine lubrication apparatus of the present invention, the air pressure after restarting the engine is prevented while preventing the oil pressure in the lubrication path from decreasing without increasing the size of the oil pump. Locked state can be avoided.

Further, the air in the oil pump is easily released, and the cooling efficiency around the piston is not lowered. Furthermore, the communication passage for venting air can be secured without increasing the number of parts. Furthermore, air can be discharged smoothly and the shape of the communication passage is simplified,
Easy to form.

[Brief description of drawings]

FIG. 1 is a right side view of a motorcycle showing an embodiment of an engine lubrication device according to the present invention.

FIG. 2 is a right side view of a crankcase.

FIG. 3 is a sectional view taken along the line III-III of FIG. 2 (a plan sectional view of the engine).

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a system diagram of a lubricating device.

[Explanation of symbols]

6 engine 12 crankcase 24 crankshaft 38 Lubricator 39 oil pan 40 Lubricating oil 41 Oil pump 42 casing 46 Oil level of lubricating oil 47 Inner plate (component of casing) 48 Outer plate (casing component) 49a-49c Mounting bolt 53 Inlet 55 Discharge port 57,58 Oil pumping passage (lubrication route) 61 Main gallery (lubrication route) 62, 63, 74, 75 Oil supply path (lubrication path) 68,69 piston jet 70,71 Jet passage (lubrication route) 72, 73 injection holes (opening to the internal space of the engine) 78 Communication passage 79 communication holes

Continued front page    (72) Inventor Shinichi Yamada             300, Takatsuka-cho, Hamamatsu City, Shizuoka Prefecture Suzuki shares             In the company F term (reference) 3G013 AA02 AA16 AB02 BA02 BB04                       BB19 BB29 BC03 BC04 BD01                       BD42 CA16                 3G015 AA02 AB02 CA01 DA10 EA07                       FA01

Claims (4)

[Claims] 1. Lubricating oil in an oil pan is pressure-fed to each part of an engine through a lubrication path by using an oil pump driven by a crankshaft, and the oil pump has an oil level of the lubricating oil when the engine is stopped. In the engine lubricator placed higher,
A part of the lubrication path connected to the downstream side of the oil pump is arranged above the oil pump, an opening to the internal space of the engine is provided in a part of the lubrication path, and a discharge port of the oil pump is provided. A lubricating device for an engine, characterized in that the downstream side of the engine and the upstream side of the opening are communicated with each other by a communication passage that has a path cross-sectional area smaller than the lubrication path and extends upward. 2. The opening to the internal space of the engine, which is arranged above the oil pump, is a lubricating oil injection hole for lubricating and cooling the periphery of the piston.
The engine lubrication device described. 3. The casing forming the oil pump is formed by facing a plurality of members, and the communication passage is formed on a mating surface of these members.
The engine lubrication device described. 4. The engine lubrication device according to claim 3, wherein the communication passage is formed in a straight line in a substantially vertical direction.