JP2684639B2 - Engine lubrication structure - Google Patents

Abstract

PURPOSE:To improve the quality of handling at the formation work of a main passage, by forming integrally part of the main passage which connects an oil pump with a crank shaft bearing portion, at an oil pan, and the rest of the main passage at a crank case. CONSTITUTION:An oil pan 28 is provided at the lower surface of a crank case 24. Part 28b of a main passage through which lubrication oil from an oil pump is distributed to each bearing of a crank shaft, is integrally formed at the oil pan 28. The rest 24b of the main passage is integrally formed at the crank case. Both main passages 24b, 28b are so arranged that they are connected with each other at the time of the joining of the crank case 24 and the oil pan 28. Thus, the quality of handling at the formation work of the main passage is improved, and the process of the main passage formation can be facilitated.

Description

Description: TECHNICAL FIELD The present invention relates to a lubrication structure of a four-cycle engine in which lubricating oil is forcibly supplied to a portion of a crankshaft bearing or the like that requires lubrication, and particularly to an oil pump. To improve the structure of the main passage which facilitates the manufacturing process of the main passage for distributing the lubricating oil from the above to each bearing of the crankshaft.

[Conventional technology]

In a 4-cycle engine, an oil pan is attached to the lower surface of the crankcase, and the lubricating oil stored in the oil pan or the lubricating oil from an oil tank provided separately is used by an oil pump to provide a crankshaft bearing portion or the like. A lubricating device is employed in which the lubricating oil is forcibly fed to the lubrication portion and the lubricating oil dropped from the lubrication required portion is received by an oil pan.
In such a lubrication device, a main passage for guiding the lubricating oil from the oil pump to the crankshaft bearing is required, but this main passage is generally formed integrally with the crankcase (for example, Japanese Patent Laid-Open No. Sho-06-36). 54-96648).

[Problems to be solved by the invention]

By the way, generally, in the main passage, a boss portion of a route along the main passage is integrally formed in the crankcase, and elongated holes are formed in the boss portion by a drill in each direction so that the holes communicate with each other, and the end of each hole is connected. It is created by screwing a plug member (plug) into the part as needed. Therefore, when creating the main passage, it is necessary to reset the crankcase many times and change the processing direction of the hole, but the crankcase is heavy and large, and its handling is poor. However, there is a problem that workability is low.

Therefore, in view of the above conventional situation, it is an object of the present invention to provide a lubricating structure for an engine, which can be easily handled to improve workability.

[Means for solving the problem]

According to the present invention, an oil pan having a dimension in the crankshaft direction extending from a bearing at one end of a crankshaft to a bearing at the other end is disposed on the lower surface of a crankcase, and lubricating oil is supplied to a lubrication required portion in the vicinity of the oil pan. In an engine lubrication structure provided with an oil pump, a cleaner chamber accommodating an oil cleaner for filtering lubricating oil from the oil pump is provided in the vicinity of the oil pump so as to extend over both the oil pan and the crankcase, and The first main gallery is formed so as to open on the bottom surface of the pan, and the opening is detachably covered by a cap, and forms a part of a main passage for supplying the lubricating oil that has passed through the oil cleaner to the bearing portion of the crankshaft. A flat surface formed integrally with the bottom wall of the oil pan and having a length extending from the bearing at one end of the crankshaft to the bearing at the center of the first main gallery. And a second main gallery that forms the rest of the main passage is integrally formed in the crankcase, and the second main gallery is formed from the central bearing of the crankshaft to the bearing at the other end. The crankshaft has a first oil supply hole which has a crossing length and extends in parallel with the crankshaft in a plan view, and which allows one end of the first main gallery to communicate with a bearing portion of one end of the crankshaft. The oil pan is formed with a communication hole formed at a right angle to connect the central ends of the first main gallery and the second main gallery to each other, and the central end of the second main gallery is located at the center of the crankshaft. A central oil supply hole communicating with the bearing portion is formed in the crankcase in a direction perpendicular to the crankshaft, and the other end of the second main gallery is a bearing of the other end of the crankshaft. The second oil supply hole for communicating is characterized in that formed in the crankcase.

Here, the oil pan of the present invention is a dish-shaped one that is attached to the bottom surface of the crankcase and receives the lubricating oil that falls from the lubrication-required portion. Both are included.

In the present invention, the lubricating oil from the separately provided oil tank (generally having a cooling function) is pressure-fed to the lubrication required part by the oil pump, and the lubricating oil dropped from the lubrication required part to the oil pan is separated into the separate oil. The present invention can be applied to both a lubricating device of a type in which it is returned to an oil tank by a pump and a lubricating device of a type in which lubricating oil in an oil pan is directly fed under pressure to a lubrication required part.

[Action]

According to the lubrication structure of the present invention, the first main gallery forming approximately 1/2 of the main passage is integrally formed in the oil pan, and the second main gallery forming approximately the other half is integrally formed in the crankcase. The main passage length on the crankcase side is reduced accordingly. Since the oil pan is lighter and smaller than the crankcase, it is easy to handle, and as a result, the manufacturing process of the main passage is facilitated.

It is considered that if all the main passages are formed in the oil pan, the manufacturing will be easier. However, in this case, since the main passage extends over the entire width of the oil pan, this serves as a weir that separates the oil pan into the front and rear, making it difficult for the lubricating oil that falls into one of the compartments to flow into the compartment on the suction side of the pump. The function of collecting bread may be impaired.
On the other hand, in the present invention, the main passage does not extend over the entire width of the oil pan, and such a problem can be avoided.

Also, because the oil cleaner is arranged so as to extend over both the oil pan and the crankcase, the oil cleaner does not project outward from the engine peripheral wall, and the arrangement of the oil cleaner increases the engine height. The engine can be downsized without any problem.

〔Example〕

 Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

1 to 7 are views for explaining one embodiment of the present invention.

In the drawing, reference numeral 1 denotes a motorcycle on which the engine of the present embodiment is mounted, and a front fork 4 for supporting a front wheel 3 at a lower end is supported at the front end of a body frame 2 so as to be steerable left and right. A rear arm 6 that pivotally supports the rear wheel 5 at the rear end is pivotally supported vertically at the lower end, and a large fuel tank 7 and a seat 8 are mounted on the upper portion in order from the front. An engine unit 9 is suspended and supported below the front part of the body frame 2.

The engine unit 9 is an air-cooled 4-cycle parallel 2
A cylinder type, a cylinder block 11, a cylinder head 12, and a head cover 13 are stacked on a front portion of an upper surface of a crankcase 10 in a state where the cylinder block 11, the cylinder head 12, and the head cover 13 are inclined forward by approximately 45 degrees with respect to a horizontal plane.

Above the left and right cylinders 11a and 11b of the cylinder block 11, pistons 14a and 14b and concave portions 12 of the cylinder head 12 are provided.
a and 12b, a combustion chamber 14 is formed. The intake and exhaust ports communicating with the combustion chamber 14 have three intake valves 15a and one exhaust valve 1a.
Two 5b are arranged. A driven sprocket 16c is fixed to the right end of the intake cam shaft 16a and the exhaust cam shaft 16b for the intake valve 15a and the exhaust valve 15b when viewed from the rear of the vehicle (the same applies hereinafter).

The pistons 14a, 14b are connected to a pair of crank arm portions 18a, 18b of the crankshaft 18 by connecting rods 17a, 17b, respectively, and a portion between the two crank arm portions 18a, 18b of the crankshaft 18 is a central bearing. The left and right outer portions are supported by left and right bearings 19a and 19b, respectively.

The crankcase 10 has an upper / lower split structure divided into upper and lower cases 23 and 24. The split surface A is inclined so that the front side becomes lower when mounted on a vehicle. Above left, right,
The center bearings 19a to 19c are formed at a portion closer to the front side of the division surface A. A pivot portion 24a for pivotally supporting the front end of the rear arm 6 is formed integrally with the rear end of the lower case 24.

A drive sprocket is located on the right side of the crankshaft 18
The sprocket 18c and the camshaft 16 are integrally formed.
A cam chain 20 is wound between the driven sprockets 16c of a and 16b. The cam chain 20 is disposed so as to pass through the cylinder head 12, the cylinder block 11, and the chain case portions 12c, 11c, and 23a that are bulged on the right side walls of the case 23. Behind this cam chain 20, a tensioner 60
Is provided, and the chain pressing member 60 of the tensioner 60 is provided.
The lower end of a is rotatably supported by a pin 61a. On the outer side of the pin 61a, a bolt 10a for connecting the upper and lower covers 23, 24 is located so as to be substantially orthogonal to the axial center of the pin 61a, which prevents the pin 61a from coming off. ing.

A gear shift main shaft (main shaft) 32 is disposed on the rear side of the crankshaft 18 of the upper case 24 and above the split surface A. A shaft (drive shaft) 35 is provided. The transmission main shaft 32 has bearings 32b and 32c at both left and right ends, and the transmission auxiliary shaft 35 has a bearing 3
It is pivotally supported by 5b and 35c respectively.

A wet multi-plate clutch 33 is mounted on the right end of the transmission main shaft 32, and a reduction gear 33b fixed to an outer 33a of the clutch 33 meshes with a reduction small gear 22 fixed to the crankshaft 18. ing. The transmission gears 32a and 35a of the respective stages mounted on the transmission main shaft 32 and the sub shaft 35 are in mesh with each other, thereby forming a constant mesh transmission.

The left end of the transmission countershaft 35 protrudes outward from the left side wall of the crankcase 10, and a sprocket 36 for rear wheel drive is mounted on the protruding portion, between the sprocket 36 and the driven sprocket 5a of the rear wheel 5. Has a transmission chain 37 wound.
A chain cover 38 is arranged outside the sprocket 36 so as to cover it, and a case cover 42 is arranged outside the cover 38.

A front balancer shaft 47 is provided in a portion of the lower case 24 in front of the crankshaft 18 and below the dividing surface A, and a rear balancer shaft 48 is provided in a portion of the upper case 23 behind the crankshaft 18 and above the dividing surface A. Are arranged in parallel with the crankshaft 18, and the line connecting the shaft cores of both balancer shafts 47 and 48 is located in front of the shaft core of the crankshaft 18. For the front and rear balancer shafts 47 and 48, the support shaft 59 is inserted into the balancer body 49,
The needle bearing 51 is arranged between the two.
Reference numeral 52 is a positioning plate that regulates the axial position of the balancer shafts 47 and 48, which is fixed to the crankcase. Further, the driven gears 47a and 48a fixed to the left end portion of the balancer body 49 are both meshed with the balancer gear 21 fixed to the crankshaft 18, so that they rotate in the opposite direction to the crankshaft 18. Has become.

Further, the front side portion of the chain case portion 23a on the right side wall of the crankcase 10 is relatively inward due to the case portion 23a and an oil pump accommodating portion, which will be described later, and its cover 61 bulging rightward. The water pump 53 for circulating the cooling water is arranged in the hollow portion.
The suction port formed in the axial center of the water pump 53 is connected to the radiator 62, and the discharge port 53b formed on the upper side in the tangential direction.
Is connected to the front side of the cylinder block 11 and communicates with the cooling jacket 11d.

A pump drive gear 25 is provided at the right end of the crankshaft 18.
Is installed. Below this pump drive gear 25,
A feed pump 26 for supplying the lubricating oil from the oil tank 63 having a function as an oil cooler to the lubricated portions such as the bearings 19a to 19c of the crankshaft 18 and the oil pan 28.
The scavenging pump 27 for sending the lubricating oil inside the oil tank 63 is arranged in parallel at the vehicle front-rear position,
The pump drive gear 25 is the input gear 26 of the feed pump 26.
a, the input gear 26a is the input gear of the scan bend pump 27
It meshes with 27a in order.

The suction port 27b of the scavenging pump 27 is connected to the oil pan 2
It is connected to one end of a strainer housing 29 immersed in the housing 8, and the discharge port 27c is connected to an oil tank 63 by an oil hose 64. Further, the suction port 26b of the feed pump 26 is connected to the oil tank 63 by an oil hose (not shown), and the discharge port 26c is formed across both the oil pan 28 and the lower case 24 and has an oil cleaner 31.
Is connected to the inside of a cleaner chamber 28a that accommodates. 6
Reference numeral 5 denotes an oil relief valve connected to the communication passage 28f, which opens when the pressure inside the cleaner chamber 28a exceeds a set value and releases the pressure into the oil pan 28. The bottom of the cleaner chamber 28a is covered with a cap 30, which has a three-tiered structure including the lower case 24, the oil pan 28, and the cap 30.

The cleaner chamber 28a is connected to a first main gallery (a part of the main passage) 28b formed integrally with the oil pan 28 via a communication passage 30a formed in the cap 30. The first main gallery 28b is parallel to the crankshaft 18 up to the central portion in the vehicle width direction and is low in the central side, as shown mainly in FIG. 1 when the oil pan 28 is viewed from the bottom and FIG. 2 showing a cross section thereof. The base end portion (one end portion) 28d is connected to the right bearing (one end bearing) 18b of the crankshaft 18 through the first oil supply hole 24f, and the tip end portion (central end portion) 28c is formed. Is the second main gallery formed in the lower case 24 through the communication hole 28h (the rest of the main passage)
It is connected to the central end 24c of 24b. And the second
The central end portion 24c of the main gallery 24b is connected to the central bearing 19c of the crankshaft 18 through the central oil supply hole 24g, and the tip end (the other end portion) 24d is connected through the second oil supply hole 24h to the left bearing 19c.
Connected to a. The second main gallery 24b is further branched into a sub gallery 24e, which communicates with the respective lubrication required parts such as the rear balancer shaft and the speed change shaft. Furthermore, the second main gallery 24b is also connected to a sub gallery 28e formed in the oil pan 28, and the gallery 28e communicates with the bearing portion of the front balancer shaft.

As shown in FIG. 3, the strainer housing 29 is located below between the weight 49b of the front balancer shaft 47 and the crank arm 18a of the crankshaft 18. The housing 29 has ribs 29a and 29b on which the weight 4
It is formed upright toward 9b and the crank arm portion 18a. The ribs 29a and 29b are for scraping off the oil that goes around with the weight 49b and the like, and immediately returning it to the oil pan 28.

A starter motor 43 is disposed behind the oil pan 28 on the lower surface of the lower cover 24. This cell motor 43
The output shaft 43a is located inside the generator cover 44 penetrating the lower cover 24, and the drive gear 43b attached to the output shaft 43a is located outside the left bearing 19a of the crankshaft 18 via the idle gear 45. It meshes with a starting gear 46 mounted via a one-way clutch.

 Next, the operation and effect of this embodiment will be described.

In the apparatus of this embodiment, the lubricating oil from the oil tank 63 is discharged into the cleaner chamber 28a by the feed pump 26, is filtered there, and is filtered from the communication passage 30a to the first main gallery 28b,
The left and right bearings 19a and 19b, the central bearing 19c of the crankshaft 18, or the front and rear balancer shafts 4 are passed through the second main gallery 24b.
After being supplied to the lubrication required parts such as the bearings 51 of the 7,48 and lubricating the parts, the parts fall naturally and collect in the oil pan 28. The lubricating oil in the oil pan 28 is sucked into the scavenging pump 27 via the strainer housing 29,
It is returned to the oil tank 63.

Here, when the lubricating oil naturally drops, the lubricating oil rotates together with, for example, the balancer shafts 47 and 48 or the crankshaft 18, and thus returns to the oil pan through a complicated path. On the other hand, in this embodiment, the front balancer shaft is
47 weight 49b, crankshaft 18 crank arm 18a, 18
Since the ribs 29a, 29b are formed so as to be close to the rotation region of b, most of the lubricating oil that rotates with the ribs 29a, 29b.
It is separated by b and immediately drops into the oil pan 28.

In the lubricating device in which each part is lubricated by such a flow of lubricating oil, as described above, in the conventional structure, the main gallery that is the main passage is heavy and large, and is integrated with the crankcase, which is difficult to handle. Since it was formed, there was a problem that the workability in the step of forming the main passage was poor. On the other hand, in the present embodiment, the first main gallery 28b has a small and lightweight oil pan 2 which is easy to handle.
Since it is formed in 8, the length of the main passage to be formed in the lower case 24 is shortened by that much, and the main passage preparation work is greatly facilitated.

When the main gallery is formed over the entire width of the oil pan as described above, the first main gallery 28b
Is projected so as to form a ridge on the inner surface of the bottom wall of the oil pan 28, the inner surface of the bottom wall of the oil pan 28 is connected to the strainer housing 29 side and the cleaner chamber 28a side by the ridge of the first main gallery 28b. The lubricant oil that has been separated from the cleaner chamber 28a and has fallen toward the cleaner chamber 28a is less likely to be sucked by the scavenging pump 27, so that the lubricant oil cannot be used efficiently. In the present embodiment, the second main gallery 24b of the main gallery
Is formed on the lower case 24 side, the oil pan 28 is not divided into two chambers, and the above-mentioned problem can be avoided.

Further, in this embodiment, since the first main gallery 28b is formed obliquely from the bottom of the oil pan 28, there is no hole in the peripheral wall of the oil pan 28. Therefore, the main gallery can be formed even for an oil pan having a very thin upper and lower thickness as in this embodiment.

Furthermore, since the ribs 29a and 29b are provided in this embodiment, most of the lubricating oil that rotates with the crankshaft 18 and the front balancer shaft 47 immediately falls into the oil pan 28, and the deterioration of the lubricating oil is suppressed accordingly. it can.

[Advantages of the Invention] As described above, according to the lubricating structure for an engine of the present invention, the oil cleaner is arranged so as to cover both the oil pan and the crankcase, so that the outward protrusion of the oil cleaner is avoided. As a result, the engine can be downsized, and the first main gallery forming a part of the main passage for passing the oil pump and the crank bearing is used as an oil pan and the remaining second main gallery is used as a crank. Since it is formed integrally with the case and the communication hole for communicating both main galleries is formed in the direction perpendicular to the crankshaft, there is an effect that the handling in the main passage forming work is improved and the main passage forming process can be facilitated. In this case, the collecting function of the oil pan is not impaired.

[Brief description of the drawings]

1 to 7 are views for explaining a lubrication structure according to an embodiment of the present invention. FIG. 1 is a bottom view of the same, and FIG.
1 is a sectional view taken along line II-II of FIG. 1, FIG. 3 is a sectional side view of a strainer housing portion, FIG. 4 is a sectional view taken along line IV-IV of FIG. 1, and FIG. FIG. 6 is a partial sectional side view of the engine, FIG. 6 is a sectional plan development view thereof, and FIG. 7 is a side view of a motorcycle equipped with the engine of the embodiment. In the figure, 19a to 19c are crankshaft bearings, 24 is a lower case (crankcase), 24b is a second main gallery (the rest of the main passage), 26 is a feed pump, 28 is an oil pan, 28
b is the first main gallery (a part of the main passage).

Claims (1)

(57) [Claims] 1. An oil pan having a dimension in the crankshaft direction extending from a bearing at one end of the crankshaft to a bearing at the other end is provided on the lower surface of the crankcase, and lubricating oil is supplied to a lubrication required portion in the vicinity of the oil pan. In an engine lubrication structure provided with an oil pump, a cleaner chamber accommodating an oil cleaner for filtering lubricating oil from the oil pump is provided in the vicinity of the oil pump over both the oil pan and the crankcase, and A first main gallery which is formed so as to be opened on the bottom surface of the oil pan and which is detachably covered with a cap to form a part of a main passage for supplying the lubricating oil that has passed through the oil cleaner to the bearing portion of the crankshaft. The first main gallery is integrally formed on the bottom wall of the oil pan and has a flat length extending from the bearing at one end of the crankshaft to the bearing in the center. The second main gallery forming the rest of the main passage is integrally formed in the crankcase, and the second main gallery is formed from the central bearing to the other end of the crankshaft. A crankshaft having a first oil supply hole for communicating one end portion of the first main gallery with a bearing portion at one end of the crankshaft. The oil pan is formed with a communication hole that is formed in a direction perpendicular to the axis and that communicates the central ends of the first main gallery and the second main gallery with each other, and the central end of the second main gallery is the center of the crankshaft. A central oil supply hole communicating with the bearing part of the crankshaft is formed in the crankcase in a direction perpendicular to the crankshaft, and the other end of the second main gallery is connected to the other end of the crankshaft. Lubricating structure for an engine that the second oil supply hole, characterized in that formed in the crankcase that communicates to the parts.