JP2756139B2 - Lubrication structure of internal combustion engine - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a lubrication structure for an internal combustion engine having a generator attached to an end of a crankshaft.

(Prior Art) In an internal combustion engine having a lubricating structure in which a rotor of a generator is attached to an end of a crankshaft and lubricating oil is supplied to the crankshaft via a lubricating oil supply path, a lubricating oil supply path is usually used. Is provided on the side opposite to the rotor of the crankshaft (see, for example, Japanese Patent Application Laid-Open No. 58-211518).

(Problems to be Solved by the Invention) However, in an internal combustion engine in which the lubricating oil supply passage is provided on the side opposite to the rotor of the crankshaft, a pulley is mounted on the side opposite to the rotor of the crankshaft, and the camshaft and various auxiliary machines are mounted by a timing belt. It was not possible to adopt a method of driving the kind. This is because the timing belt is of a dry type and cannot be used in an environment where lubricating oil is present.

Further, it is possible to drive an auxiliary device such as an oil pump or a water pump on a separate shaft through a gap or the like on the side opposite to the rotor of the crankshaft where the lubricating oil supply passage is provided, It is also impossible to directly connect auxiliary equipment to
In any case, there is a problem that the degree of freedom of design of the crankshaft on the side opposite to the rotor is limited.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is to provide a lubrication structure for an internal combustion engine capable of improving a degree of freedom in designing a crankshaft on a side opposite to a rotor.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a lubrication structure for an internal combustion engine comprising a generator rotor attached to one end of a crankshaft rotatably supported in a crankcase,
A lubricating oil supply passage for supplying lubricating oil to the crankshaft is formed on the shaft end side of the crankshaft to which the rotor is attached, and lubricating oil is supplied through a crankcase cover that covers the rotor from the outside in the crankshaft direction. It is characterized in that it is supplied to the crankshaft.

(Operation) According to the present invention, since the lubricating oil supply passage for supplying lubricating oil to the crankshaft is formed on the shaft end side of the crankshaft where the rotor is mounted, a dry-type lubricating oil passage is provided on the opposite side of the crankshaft from the rotor. Various accessories such as a pulley, an oil pump and the like for driving the timing belt can be directly connected, and the degree of freedom in designing the crankshaft on the side opposite to the rotor can be increased.

Embodiment An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a side sectional view of a generator portion of an internal combustion engine provided with a lubricating oil according to the present invention, and FIG. 2 is a sectional view taken along line II-II of FIG.

The internal combustion engine according to the present embodiment has a crankcase
A crankshaft 2 is rotatably supported in the crankcase 1. That is, the crankshaft 2
Is rotatably supported by a plain bearing 3 fitted into the crankcase 1, and a flange 4 is integrally formed at an end of the crankshaft 2 facing the outside of the crankcase 1. The end surface 4a of the flange portion 4 of the crankshaft 2 and the end surface 5a of the crank web 5 are formed in the shaft penetrating portion of the crankcase 1 (the portion through which the crankshaft 2 penetrates).
The thrust force acting on the crankshaft 2 in the axial direction is received by the outer wall surfaces 1a and 1b, respectively.

A large-diameter oil passage 6 is provided at the center of the end of the crankshaft 2.
Are formed in the axial direction, from the oil passage 6 to a small-diameter oil passage 7.
The oil passage 7 is formed on the outer peripheral surface of the journal 2a of the crankshaft 2 (the inner peripheral surface of the plain bearing 3). An oil passage 8 communicating with the oil passage 6 is formed in the end face of the crankshaft 2 in a radial direction, and an oil passage 9 extends from the oil passage 8 by a predetermined amount in the radial direction from the axis of the crankshaft 2. The oil passage 9 has a small diameter oil passage 10 extending radially toward the outer peripheral surface of the crank pin 2b (the inner peripheral surface of the large end of the connecting rod, not shown). Is formed.

By the way, in the present embodiment, the rotor 12 of the generator 11 is connected to the flange 4 integrally formed at the end of the crankshaft 2 with a plurality of bolts 13. The rotor 12 has a drum shape that opens outward (to the left in FIG. 1), and a magnet 14 is attached to the inner periphery thereof.

The generator 11 includes a ring-shaped coil core 15 housed inside the rotor 12.
Are attached together with a retaining plate 17 together with three bolts 25 to the inside of a crankcase cover 16 that covers the generator 11. The retaining plate 17 is formed in a triangular shape as shown in FIG. 2, and a circular hole 17a and an oblong hole 17b are formed in the center thereof.

On the other hand, a pipe flange-like connecting fitting 18 is connected to the end face of the crankshaft 2 by a plurality of bolts 19 inserted through a flange portion 18a of the connecting fitting.
An O-ring 20 for sealing is interposed on the end face of the crankshaft 2. As shown in the figure, the tip of the connecting member 18 is inserted into a circular hole 17a formed in the plate 17, and an oil passage 18 communicating with the oil passage 6 is provided at the center of the connecting member 18.
b is pierced.

On the other hand, a boss 16a protruding inward at the center of the crankcase cover 16 has circular holes 16b of large and small diameters,
An oil passage 16c is formed, and a sleeve 21 is fitted and held in the circular hole 16 so as to be slidable in the axial direction. An oval flange portion 21a formed at an end of a portion of the sleeve 21 projecting outside the boss portion 16a has an outer periphery fitted in an oval hole 17b formed in the plate 17 in the width direction. The entire sleeve 21 is constantly urged in the direction of the connecting bracket 18 (to the right in FIG. 1) by a spring 23 compressed between the flange portion 21a and the washer 22.
The end face of the flange portion 21a is pressed against the end face of the connection fitting 18 with a constant force. The height of the flange 21a in the vertical direction is set to be larger than the inner diameter of the circular hole 17a of the plate 17. An oil passage 21b communicating with the oil passage 16c and the oil passage 18b is provided through the center of the sleeve 21. Furthermore, the oilway
Reference numeral 16c is connected to the discharge side of an oil pump (not shown) via an oil passage 24 opening therethrough.

Thus, in the present embodiment, a boss member conventionally required for attaching the generator rotor 12 to the crankshaft 2 is provided.
Since a nut for tightening the boss member and a key for preventing rotation are not required, tapering of the boss member and the crankshaft 2 is not required, and the number of parts and the number of processing steps can be reduced.

Further, since the generator rotor 12 is directly connected to the flange portion 4 of the crankshaft 2, a special tool is not required for removing the generator rotor 12, and the maintainability of the generator 11 is significantly improved.

Furthermore, since the boss member is no longer necessary, the length of the crankshaft 2 can be reduced by at least the axial length of the boss member to reduce the weight thereof,
Flange 4 of crankshaft 2 and crankcase cover
A dead space is formed between the lubricating oil supply passage 16 and the lubricating oil supply passage as in this embodiment.

By the way, oil (lubricating oil) discharged from an oil pump (not shown) during operation of the internal combustion engine is supplied to the oil passages 16 c and 21.
b, 18b, the oil is supplied to the oil passage 6, and a part of the oil is supplied from the oil passage 7 to the circumferential portion of the plain bearing 3 so that the sliding surface between the plain bearing 3 and the crankshaft journal 2a and the thrust bearing are formed. Lubrication is performed between the outer wall surfaces 1a and 1b and the end surfaces 4a and 5a of the crankcase 1 that is configured. Another oil flows through the oil passage 9 through the oil passage 8, and a part of the oil flows through the oil passage 9.
From 10 reaches the sliding surface between the crank pin 2b and the large end of the connecting rod, and lubricate this portion.

Thus, in the internal combustion engine according to the present embodiment, the oil passages 16c, 21b, 18b constituting the lubricating oil supply passage for supplying the lubricating oil to the crankshaft 2 are connected to the generator rotor 12 of the crankshaft 2.
Is formed on the shaft end side where the shaft is mounted, so that various auxiliary parts such as a pulley and an oil pump for driving a dry timing belt are provided on the end of the crankshaft 2 opposite to the rotor (the side opposite to the side where the generator rotor 12 is mounted). Machines (both not shown) can be directly connected, and the degree of freedom in designing the crankshaft 2 on the side opposite to the rotor can be increased.

 Here, the disassembly procedure of the generator 11 will be described.

That is, first, if the bolts connecting the cover 16 to the crankcase 1 are removed, as shown in FIG. 3, the cover 16 is easily pulled out along with the coil core 15, the plate 17, the sleeve 21 and the like in the axial direction outward. be able to. At this time, the sleeve
21 is urged in the direction of the plate 17 by the spring 23, and the vertical height of the flange portion 21a is set to be larger than the inner diameter of the circular hole 17a of the plate 17 as described above. 21a abuts against the plate 17 as shown in FIG.
Is prevented from coming off.

When the cover 16 is pulled out in the axial direction as shown in FIG. 3, the heads of the bolts 13 connecting the generator rotor 12 to the flange portion 4 of the crankshaft 2 are exposed. For,
If the bolts 13 are loosened and removed, the generator rotor 12 can be easily removed from the flange portion 4. The assembling of the generator 11 is performed in the reverse procedure.

As described above, since the disassembly and assembly of the generator 11 of the internal combustion engine are facilitated, the maintainability of the generator 11 or the entire internal combustion engine is improved. When disassembling and assembling the entire internal combustion engine, as described above, since the crankcase 1 is vertically divided, the internal combustion engine can be overhauled by lifting the upper half of the crankcase 1. In this case, the crankcase 1 does not necessarily need to be split vertically, and it suffices if the division surface is on a plane passing through the center of the crankshaft 2.

(Effects of the Invention) As is apparent from the above description, according to the present invention, in a lubrication structure for an internal combustion engine in which a rotor of a generator is attached to one end of a crankshaft rotatably supported in a crankcase, A lubricating oil supply passage for supplying lubricating oil to the crankshaft is formed on the shaft end side of the crankshaft to which the rotor is attached, and lubricating oil is supplied through a crankcase cover that covers the rotor from the outside in the crankshaft direction. Since the crankshaft is supplied to the crankshaft, the effect of improving the degree of freedom in designing the crankshaft on the side opposite to the rotor can be obtained.

[Brief description of the drawings]

1 is a side sectional view of a generator portion of the internal combustion engine according to the present invention, FIG. 2 is a sectional view taken along the line II-II of FIG. 1, and FIG. 3 shows an exploded state of the generator portion of the internal combustion engine. It is a side sectional view. DESCRIPTION OF SYMBOLS 1 ... Crank case, 2 ... Crank shaft, 4 ... Flange part, 11 ... Generator, 12 ... Generator rotor, 16 ... Crank case cover, 16c, 18b, 21b ... Oil passage (lubricating oil) Supply path).

Claims (1)

(57) [Claims] 1. A lubricating oil supply passage for supplying lubricating oil to said crankshaft in a lubricating structure for an internal combustion engine comprising a generator rotor attached to one end of a crankshaft rotatably supported in a crankcase. An internal-combustion engine, wherein lubricating oil is supplied to the crankshaft through a crankcase cover that covers the rotor from the outside in the crankshaft direction. Lubrication structure.