JPS5970857A - Internal-combustion engine - Google Patents

Abstract

PURPOSE:To enhance the rigidity of a crank casing while its weight is restrained, and as well to enhance the durability of an engine entirely, by providing a reinforcement formed therein with a hole through which a connecting rod may be inserted, to the crank casing in the part corresponding to engine cylinders. CONSTITUTION:In an upper crank casing 13, a reinforcement 40 formed with a hole 39 through which a connecting rod 34 is smoothly inserted, is provided to the position facing a storing hole into which a wet sleeve 25 is inserted. With the provision of the reinforcement 40, the rigidity of the upper crank casing 13 is greately increased and the durability of an engine is remarkably enhanced.

Description

[Detailed description of the invention] The present invention relates to internal combustion engines.

Conventionally, in internal combustion ITi engines, the inner diameter of the communication hole provided in the crankcase to communicate between the crankcase and the cylinder is equal to or larger than the inner diameter of the cylinder. In order to improve the durability of the crankcase and cylinders, it has been difficult to increase the rigidity of these parts by increasing the thickness of these parts or by providing reinforcement inside them, while at the same time keeping the increase in engine weight to a relatively small amount. Ta.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an internal combustion engine in which the durability of the crankcase and cylinders is high and the weight of the engine is relatively small.

In the internal combustion engine according to the present invention, a connecting rod and a screw cylinder are connected via a piston pin, and then a cylinder that accommodates the screw cylinder is connected to a crankcase. It is characterized by including a reinforcing part having an insertion hole through which the pad is inserted and tightened.

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

In the figure, 4 for a motorcycle as an embodiment of the present invention is shown.
Seikle 4-cylinder gasoline] The cylinder head 2 of the carrot 1 is formed with four intake ports 3 and four exhaust ports 1-4 for each cylinder, and the intake and exhaust ports 3 and 4 are closed so as to be openable and closed. The intake valve 5 and the exhaust valve 6 are fitted so as to be openable and closable.

Furthermore, compression coil springs 7 are installed in the intake and exhaust valves 5 and 6, respectively, in a direction that allows the intake and exhaust boats 3 and 4 to be closed at all times.

Furthermore, camshafts 9 and 10 are pivotally supported on a cylinder head cover 8 provided above the intake and exhaust valves 5 and 6, respectively, with bias toward the negative side. On the other hand, crankshaft 12
is rotatably supported by an upper crankcase 13 and a lower crankcase 14 via a needle bearing 15 and a ball bearing 16. The camshafts 9 and 10 are connected to the crankshaft 12 by a camshaft left drive transmission device consisting of a pair of gears 17 provided in the upper crankcase 13.
It is designed to be rotationally driven in synchronization with the rotation of the crankshaft 12. Furthermore, the spacer 1 no. 20 fitted to the outer race 19 of the ball bearing 16 and the outer ring 21 of the needle bearing 15 are connected to the fixed pin 2.
2 are positioned and fixed to the upper crankcase 13, respectively.

On the other hand, the upper crankcase 13 is provided with cylinder storage holes that are equal to each other because they are cylinders, and a wet sleeve 25 that constitutes the cylinder wall is inserted into these cylinder storage holes together with the cylinder head 2. - The cylinder 1 of the engine forms a combustion chamber and is fixed to the upper crankcase 13 at its lower end.

Each web (sleeve 25) accommodates a bislin 26 that is reciprocally movable and has a substantially oval cross section perpendicular to the cylinder axis.

There is a screw 1 pin insertion hole 2 on the side of each screw 1-26.
7 is provided, and C is inserted through the screw 1 insertion hole.
A piston pin 28 is inserted. The axial movement of the screw 28 is restricted by two piston pin clips.

The screw 1 hembin 28 also has a small end 35 of a connecting rod 34, the large end 31 of which is connected to the crank pin 32 of the crankshafts 1 to 12 via a needle bearing 33.
are connected.

Here, the big end 31 of the connecting rod 34 is connected to the crank bin 3.
2 is integrally molded with an insertion hole into which the number 2 is inserted. Therefore, the crankshaft 12 is of a so-called build-up type in which the crank bin 32 and the crank arm 36 are assembled by press-fitting.

According to the present invention, in the upper crankcase 13,
A reinforcing portion 40 having an insertion hole 39 large enough for the connecting rod 34 to be pushed through is provided at a portion extending into the storage hole in which the web 1-sleeve 275 is stored.

By providing this reinforcing portion 40, the rigidity of the upper crankcase 13 is dramatically increased compared to conventional internal combustion engines, and its durability is significantly improved. Further, by increasing the rigidity of the upper crankcase 13 in this way, the C1 wet sleeve 25 and the lower crankcase 14 are firmly supported by the upper crankcase 13, so the wet sleeve 25 and the lower crankcase 14 are relatively The durability of the material can also be improved.

The upper crankcase 13 is also provided with an opening 41 at a predetermined position on its side, into which the piston pin 28 is inserted during the manufacturing process. A lead cap 42 made of alloy steel is fitted into the open portion 41 after the screw pin 28 is inserted.

Furthermore, L! The accrank case 14 is provided with lance transmissions 1 to 45 as shown in Tsutomi;
It is rotatably supported by the lower crankcase 14 via a needle bearing 17 and a ball bearing 48. At one end of the main shaft 1771-46, there is a multi-disc hydraulic latch/'I9.
50 is rotatably attached to the lower crankcase 14 via a needle bearing 51 and a ball bearing 52. The countershaft 50 protrudes outside the lower crankcase 14 as an output shaft, and a swing lock 1-54 for driving a transmission chain 53 is fixed to the protrusion of the countershaft 50.

Further, 56 is a so-called primary speed reduction device. Furthermore, 5
7, 58, 59 and 60 respectively indicate a cover, a spark plug, an oil pan and a starter, and 61 and 62 indicate a starter jacket.

Next, screws 1 and 26 are attached to the upper crankcase 13 of the internal combustion engine configured as described above. Bis 1 ~ Bin 28.
The procedure for assembling the crankshaft 12 and wet sleeve 25 will be explained.

First, the crankshaft 12 is attached to the upper crankcase 13 with the needle bearing 15 and spacer 20 interposed therebetween. At this time, crankshaft 1
The connecting rod 3/'I installed in the upper crankcase 13 is inserted into the insertion hole 3 provided in the reinforcing part 40 of the upper crankcase 13.
9. Further, at this stage, the cylinder head 2 and wet sleeve 25 are not attached.

Next, the piston 26 is placed over the small end 35 of the connector 34 and the piston pin 28 is attached (screws).
The pin 28 is inserted through the opening 41 on the side of the upper crankcase 13 and is inserted through the piston pin insertion hole 27 of the piston 26. After that, by attaching one side of the piston pin clip 29, screw 1 is removed.
The connecting rod 34 is connected to the connecting rod 34. however,
The other end of screw 1 to bin clip 29 is installed in screw 1 in advance. After the screws 1 to 26 are connected to the connecting rod 34, the screws 1 to 26 are connected.
Fit the wet sleeve 125 into the housing hole of the upper crankcase 13, fit the wet sleeve 25 into the storage hole of the upper crankcase 13, and attach the one-side grip 42 to the opening 41'C.
The assembly of each of the above members into the upper crankcase 13 is completed.

As detailed above, in the internal combustion engine according to the present invention -
C is the part corresponding to the cylinder of the crankcase,
] Since the reinforcing part has an insertion hole through which the connecting rod can be inserted and through which the connecting rod can move, the rigidity can be increased while suppressing the weight of the crankcase, and the durability of the entire IU engine can be increased. It has been raised to a high standard.

[Brief explanation of drawings]

FIG. 1 is a partially longitudinal side view of a four-stroke, four-cylinder gasoline engine for a motorcycle according to the present invention, and FIG. 2 is a longitudinal plan view thereof. Explanation of symbols for main parts 1... 4-cycle 4-cylinder gasoline engine for motorcycles 2... Cylinder head 8... Cylinder head cover 9.10... Cam shirt ]-12...Crankshaft 17F 1-13...
・Upper crankcase 14... Lower crankcase 25... Wet sleeve 26... Piston 28... Screw 1 to Bin 29... Piston Pink lip 34...
・Connecting rod 39...Insertion hole 40...
... Reinforcement part 41 ... Frontage part 42 ...
...Lead Cap Applicant Book 1111 Technique? Motohiko Jinmura, patent attorney, agent of TLL Kogyo Co., Ltd.

Claims (1)

[Claims] After connecting the connecting rod and screw 1 through a piston pin, a cylinder housing the piston is connected to a crankcase, and the crankcase has an insertion hole on the right side through which the connecting rod is inserted. An internal combustion engine, characterized in that it includes a reinforcement section.