JP2003161130A - Lubricant oil supply structure for engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricant oil supply structure for an engine which simplifies structure and smoothly supplies lubricant oil to respective parts. <P>SOLUTION: Crank shaft 22 is freely rotatably supported on a crankcase 23 through the medium of three bearings 23a, 23b and 23c arranged at established intervals. An oil passage 37 is provided to a bearing wall 23e formed in the center part of respective three bearing walls 23d, 23e and 23f on which respective three bearings 23a, 23b and 23c are mounted. Lubricant oil is supplied to the camshaft through the oil passage 37. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil supply structure for an engine mounted on a motorcycle or the like.

[0002]

2. Description of the Related Art Conventionally, some motorcycles are equipped with a V-type engine, and this V-type engine is constructed so that lubricating oil is circulated, as shown in FIGS. In the figure, reference numeral 1 is a crankshaft, and this crankshaft 1 is one of four bearing portions 2 of a crankcase 2.
It is rotatably provided by a, 2b, 2c and 2d. Further, the cam chain 5 is wound between the sprocket 1a provided in the middle portion of the crankshaft 1 and the sprockets 3a, 4a provided on the intake camshaft 3 and the exhaust camshaft 4 to form a crankshaft. When 1 is rotated, the cam shafts 3 and 4 are rotated at a predetermined timing.

An oil passage 2e which is continuous to the cam shafts 3 and 4 is provided in a bearing wall portion 2f where one of the four bearing portions 2b is formed, and lubricating oil is supplied as follows. It is like this.

That is, as shown in FIG. 8, the oil pump 8 sucks the lubricating oil through the oil strainer 9, the oil is sent to the oil filter 10, and the oil is cleaned by the oil filter 10. , Sent to the main gallery 6.

Then, as shown in FIG. 7, lubricating oil is supplied to sliding portions between the crankshaft 1 and the bearing portions 2a, 2b, 2c, 2d and a connecting rod (not shown), and at the same time, the bearing portion 2b. Lubricating oil is supplied to each of the camshafts 3 and 4 through the oil passage 2e of the bearing wall portion 2f in which the shaft is formed.

[0006]

However, in such a conventional one, since the cam chain 5 is provided in the central portion of the crankshaft 1, the bearing portions 2a, 2b, 2c, 2d at four places are provided. Is required, and the hydraulic pressure acts on each of the bearing portions 2a, 2b, 2c, 2d, the structure becomes complicated, and the oil passage of the bearing wall portion 2f in which the bearing portion 2b is formed is formed. Two
In some cases, the hydraulic pressure to e became weak, and the lubricating oil could not be supplied satisfactorily to each location.

Therefore, it is an object of the present invention to provide a lubricating oil supply structure for an engine, which can have a simple structure and can supply the lubricating oil satisfactorily to each place.

[0008]

In order to achieve the above object, the present invention as set forth in claim 1, is such that a crankshaft is rotatably supported on a crankcase via three bearing portions arranged at predetermined intervals. An oil passage is formed in the bearing wall portion formed in the central portion of the three bearing wall portions in which the respective three bearing portions are formed, and lubricating oil is supplied to the camshaft through the oil passage. It is characterized in that the lubricating oil supply structure for an engine is configured as described above.

According to a second aspect of the invention, in addition to the structure of the first aspect, crank webs are adjacent to both sides of the bearing wall portion formed in the central portion in the crank shaft direction. And

The invention described in claim 3 is the invention according to claim 1 or 2.
In addition to the configuration described in (1), a starter one-way gear is arranged on one of the outer sides of the crankcase, and a cam chain is arranged on the other side.

The invention according to claim 4 is the invention according to claims 1 to 3.
In addition to the configuration described in any one of the above 1, the oil passage is formed in the bearing wall portion of the V-type engine.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on embodiments.

1 to 6 show an embodiment of the present invention.

First, the structure will be described. Reference numeral 21 in FIG. 1 is a four-cylinder V-type engine of a motorcycle.
The crankshaft 22 is rotatably supported by three bearing portions 23a, 23b, 23c of the crankcase 23.

Connecting rod mounting portions 22a are formed at two positions on the crankshaft 22, and two connecting rods 24 are attached to each connecting rod mounting portion 22a via bearings so as to be rotatable. Further, the crankshaft 22 has a bearing portion 23a,
Two oil passages 22c are formed from the support portion 22b supported by 23c to the connecting rod attachment portion 22a.

Further, the crankshaft 22 has
On the outside of the crankcase 23, the starter one-way gear 2
5, the camshaft drive sprocket 22d is integrally formed on the opposite side of the outer side of the crankcase 23.

As shown in FIGS. 1 and 2, the camshaft drive sprocket 22d, the intake sprocket 26a provided at the ends of the pair of left and right intake camshafts 26, and the three sprockets 22d, 26.
intermediate sprocket 28 arranged substantially in the center of a, 26a
The cam chain 29 is wound around and the driving force from the cam shaft drive sprocket 22d is applied to the cam chain 29.
Is transmitted to the intake camshaft 26 via.

Further, a connecting chain 3 is provided between a sprocket 27 provided adjacent to the intake sprocket 26a separately from the intake sprocket 26a and an exhaust sprocket 31 provided at an end of the exhaust camshaft 30.
2 is wound, and the intake camshaft 26 and the exhaust camshaft 30 are rotated in synchronization with each other. As shown in FIG. 2, a hydraulic tensioner 33 is arranged in the middle of the connecting chain 32 to ensure the tension of the connecting chain 32.

On the other hand, the oil passage 3 extending from the main gallery 35 to the crankshaft 22 is formed in the bearing wall portions 23d, 23e and 23f in which the three bearing portions 23a, 23b and 23c for supporting the crankshaft 22 are formed.
6, 37, 38 are formed respectively. Then, the oil passage 3 of the bearing wall portion 23e formed in the central portion thereof
Numeral 7 extends upward from the crankshaft 22.

As shown in FIG. 3, the oil passage 37 is divided into left and right split pipes 40 and 41 at the upper end, and as shown in FIG. 5, the cam chain 29 extends in the direction of the camshafts 26 and 30. The split pipes 40 and 41 are guided to the side where they are arranged and the left and right cylinder heads 4
As shown in FIG. 4, the oil passages 44 and 45 of the oil passages 2 and 43 are connected to the one end portions of the oil passages 26a and 30a of the camshafts 26 and 30, respectively.

Thus, the left and right cylinder heads 42, 4
Since the oil is supplied from the side where the third cam chain 29 is arranged, the following advantages can be obtained.
That is, among the bearings of the cam shafts 26 and 30, the cam chain 2 is located in the bearing closest to the cam chain 29.
Since a large load acts as much as the tension of 9 acts, it is possible to perform good lubrication by supplying oil from this part side. Further, since the tensioner 33 is provided on the cam chain 29 side, it is convenient for refueling the hydraulic tensioner 33, and as shown in FIG. 6, the hydraulic pressure before lubricating the bearings of the camshafts 26, 30 is increased. Can be guided to the tensioner 33, pressure can be secured to the tensioner 33, and the hydraulic path can be simplified.

Further, the crank webs 22e of the crankshaft 22 are adjacent to both sides of the bearing wall portion 23e formed in the central portion thereof in the axial direction of the crankshaft 22.

According to this, the inter-cylinder pitch can be narrowed down, the engine 21 as a whole can be miniaturized, and when the inter-cylinder pitch is fixed (the pitch is not actively reduced). Crank web 2)
Thicken the bearing wall 23e until the space between 2e is full,
As a result, the oil passage 22c can be formed thick and the amount of supplied oil can be easily secured.

Incidentally, FIG. 6 shows a circulation path of the lubricating oil, and the lubricating oil of the clutch 48, the main shaft 49, the drive shaft 50 and the middle gear chamber 51 is supplied from the oil pump 47.

In such a structure, the lubricating oil is circulated as follows. That is,
As in the conventional case, the oil pump sucks the lubricating oil through the oil strainer, sends the oil to the oil filter, is cleaned by the oil filter, and is sent to the main gallery 35.

The bearing wall portions 23d, 23e, 2
Bearing part 2 through 3f oil passages 36, 37, 38
Lubricating oil is supplied to the sliding portions between the crankshaft 22 and 3a, 23b, 23c.

Lubricating oil further flows into the oil passage 22c of the crankshaft 22 from the oil passages 36 of the bearing portions 23a and 23c at both ends, and the lubricating oil is supplied between the crankshaft 22 and the connecting rod 24.

Further, the lubricating oil is supplied from the oil passage 37 of the bearing wall 23e at the center to one end of the oil passages 26a, 30a of the camshafts 26, 30.

In such a structure, by disposing the cam chain 29 on the outer side of the crankcase 23, the number of the bearing portions 23a, 23b, 23c can be three, and the bearing in the central portion can be provided. Lubricating oil is supplied to the camshafts 26 and 30 through the wall portion 23e. Then, as the number of the bearing walls decreases, the structure for supplying the lubricating oil can be simplified, and the oil pressure in the oil passage 37 of the bearing wall 23e at the central portion can be secured, so that the lubricating oil can be supplied to each cam. Shafts 26, 30
Can be satisfactorily supplied and the lubricating performance can be secured.

[0030]

As described above, according to the invention described in each claim, the number of bearings is three, and the lubricating oil is supplied to each cam shaft through the bearing wall at the center. Since the number of bearing walls is reduced, the structure for supplying lubricating oil can be simplified and the oil pressure in the oil passage in the central bearing wall can be secured, so that lubricating oil can be supplied to each camshaft, etc. Can be supplied to
Lubrication performance can be secured.

According to the second aspect of the invention, since the crank webs of the crankshaft are adjacent to both sides of the bearing wall portion formed in the central portion in the axial direction of the crankshaft, the pitch between the cylinders is reduced. It is possible to reduce the size of the engine as a whole, and when considering the fixed pitch between cylinders (when not trying to positively reduce the pitch), the bearing wall portion can be filled to the full distance between the crank webs. Can be made thicker, and thus the oil passage can be made thicker,
The amount of oil supplied can be easily secured.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a V-type engine according to an embodiment of the present invention cut at the center of a V-shape.

FIG. 2 is a view showing a disposition state and the like of the cam chain according to the same embodiment.

FIG. 3 is a cross-sectional view taken in a direction orthogonal to the crankshaft according to the same embodiment.

FIG. 4 is a cross-sectional view showing a cylinder head and the like according to the same embodiment.

FIG. 5 is a schematic plan view showing a flow passage chamber and the like according to the same embodiment.

FIG. 6 is an explanatory view showing a distribution route of the lubricating oil according to the same embodiment.

FIG. 7 is a schematic view showing a flow of lubricating oil of an engine showing a conventional example.

FIG. 8 is a schematic front view showing a flow of lubricating oil of the engine showing the conventional example.

[Explanation of symbols]

21 engine 22 crankshaft 23 crankcase 23a, 23b, 23c Bearing part 23d, 23e, 23f Bearing wall 24 connecting rod 25 starter one-way gear 26 Intake camshaft 26a Oil passage 29 cam chain 30 exhaust camshaft 30a oil passage 32 linked chains 37 Oil passage 35 Main Gallery

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3G013 AA09 BC01 BC02 BC11 BC20                       BD06 BD12 BD14 BD25 BD27                 3G024 AA49 BA23 DA10 DA19 EA04                       FA07

Claims (4)

[Claims] 1. A crankshaft is provided in a crankcase,
An oil passage is rotatably supported via three bearing portions arranged at a predetermined interval, and among the three bearing wall portions in which the three bearing portions are formed, the bearing wall portion formed in the central portion is provided with an oil passage. The lubricating oil supply structure for an engine is characterized in that the lubricating oil is supplied to the camshaft through the oil passage. 2. The lubricating oil supply structure for an engine according to claim 1, wherein crank webs are adjacent to both sides of the bearing wall portion formed in the central portion in the crank shaft direction. 3. The lubricating oil supply structure for an engine according to claim 1, wherein a starter one-way gear is arranged on one side of the crankcase and a cam chain is arranged on the other side of the crankcase. 4. The oil passage is formed in the bearing wall of a V-type engine.
The lubricating oil supply structure for an engine according to any one of 1.