JPH0433985B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a multi-cylinder engine, such as a horizontally opposed or similar V-type engine, having at least two cylinders extending from a crankcase to both sides.

[Conventional technology]

Multi-cylinder engines that have at least two cylinders extending from the crankcase to both sides, such as horizontally opposed or similar V-type engines, have the advantage of being well-balanced and producing less vibration during operation.

[Problem to be solved by the invention]

However, although this type of engine has the advantage of less vibration, it has a large number of parts, which not only poses an industrial disadvantage, but also makes it difficult to reduce weight.

[Means to solve the problem]

The present invention has been made to solve these problems, and provides a multi-cylinder water-cooled engine for motorcycles equipped with a plurality of cylinders having cylinder axes extending in the horizontal direction of the vehicle body, each cylinder forming one half of a crank chamber. The cylinder block is made up of a half-split case and a cylinder, and each cylinder block is connected to each other in the half-split case to form a crank chamber, and an intake hole and an exhaust hole are provided above and below the cylinder head of the cylinder. and a transmission chamber is arranged below and adjacent to a crank chamber for storing a crankshaft and a cylinder of the cylinder,
The input and output shafts of the transmission, which are parallel to the crankshaft, are housed in this transmission chamber so that they are at approximately the same height, and an exhaust muffler is connected to the exhaust hole of the cylinder head via an exhaust pipe. is arranged on the bottom wall side of the transmission chamber, and the exhaust pipe is suspended along the vertical wall of the transmission chamber on the cylinder head side.

[Effect]

Compared to an engine in which the crankcase and cylinder are prepared separately, the number of large parts is reduced.

〔Example〕

This will be explained in detail below using illustrated embodiments.

Fig. 1 is a side view of a motorcycle equipped with a multi-cylinder water-cooled engine according to the present invention, Fig. 2 is a partially cutaway plan view of the engine, Fig. 3 is a cross-sectional view taken along the - line, and Fig. 4 is - Line sectional view, Figure 5 is -
6 is a process diagram showing a method of assembling the engine, and FIG. 7 is a sectional view taken along the line -- in FIG. 3.

In the motorcycle according to the embodiment, a front wheel 4 is supported on a steering shaft tube 2 located at the front end of a steel pipe frame 1 via a front fork 3 so as to be able to turn left and right. The steel pipe frame 1 supports the rear part of the engine 6 by its main frame 5.
Further, the front portion is supported by the down tube 7 via support brackets 8 and 9, respectively. A bracket 10 is provided at the lower end of the main frame 5, and a rear arm 12 for supporting a rear wheel 11 is supported by a support shaft 13 so as to be vertically swingable. The main frame 5 has a seat support frame 1 that extends further rearward.
4 and its reinforcing frame 15 are assembled by welding,
A buffer spring 16 is attached between the seat support frame 14 and the rear arm 12. Reference numeral 17 indicates a fuel tank, and 18 indicates a passenger seat, which are each provided on the upper surface of the frame 1.

The engine 6 has a front cylinder 22 extending forward from a central crank chamber 21 and a rear cylinder 23 extending rearward.
This is a horizontally opposed four-cylinder water-cooled engine. The cylinder axes of the front cylinder 22 and the rear cylinder 23 extend in the horizontal direction. 24 is its carburetor, 25 is an air cleaner, and 26 is an exhaust pipe. Note that, as shown in FIG. 3, the exhaust pipe 26 extends downward from the exhaust hole of each cylinder,
It is connected to the exhaust muffler below the engine 6. The downwardly extending portion of the exhaust pipe 26 is suspended along the front and rear walls (cylinder head side vertical walls) of the transmission chamber, which will be described later.

More specifically, as shown in FIGS. 2 to 5 and 7, the engine 6 includes a front case 32 and a rear case 3 in which a crankshaft 31 constitutes a crank chamber 21.
3, and each case 32, 33 is formed as a cylinder block having two cylinder holes 34 each. The lower part of each of the cases 32 and 33 extends below the cylinder,
A mission case is integrally provided so that the cases 32 and 33 serve as partition walls. A cylinder head 35 is attached to cover the cylinder hole 34, and has an intake hole opening on the top surface and an exhaust hole opening on the bottom surface. A water jacket 34a is provided around the cylinder hole 34, as shown in FIG. Further, as shown in FIG. 4, a timing shaft 37 is further pivotally supported on the joint surface 36 between the front case 32 and the rear case 33, and is driven by a chain 38 from the crankshaft 31.
In the drive chamber 21a formed between the crank chamber 21 and the cover 32a covering the left outer surface of the crank chamber 21, two camshafts 41, one for intake and one for exhaust, are driven by another chain 39. 42 is a starting motor, and 43 is a disposable oil filter.

A transmission chamber 46 communicating with the crank chamber 21 is formed below the crank chamber 21 and extends between a front case 32 and a rear case 33 .
7 and an output shaft 48 are supported. Note that the input shaft 47 and the output shaft 48 are mounted at substantially the same height. One end of the input shaft 47 protrudes into the crank chamber 21b formed between the crank chamber 21 and the cover 33a covering the outer surface thereof.
A clutch 49 is provided there. A large reduction gear 53 is fixed to the clutch 49 and is driven by meshing with a pinion 52 fixed to the crankshaft 31, while also driving the input shaft 47. The output shaft 48 of the transmission drives the rear wheels 11 via a chain 54, as is well known. 40
is a lubricating oil reservoir in the crank chamber 21.

In FIG. 2, when assembling the engine, a side hole 55 provided in each cylinder wall is inserted into a piston 56 that has been previously fitted into the cylinder hole 34, and a piston pin 57 is inserted into the small end of a connecting rod 58. It is for the purpose of The covers 32a and 33a also function as a lid for this hole.

Next, a method of assembling the above engine will be explained with reference to FIG. First, the piston 56c to be fitted into the cylinder hole 34c of either the front or rear case 32c is connected to the connecting rod 5 by the piston pin 57.
8c, the piston 56d is fitted into the piston hole 34d of the other case 33d, and the piston hole is aligned with the side hole 55 formed in the cylinder (1). Next, the piston 56c connected to the connecting rod 58c is fitted into one cylinder hole 34c, and pushed in until the side hole 55 of the cylinder and the piston pin 57 substantially match (2). Next, the crankshaft 31 is supported on the bearing of one case 32c, and when the case 32c is supported with the crankshaft 31 facing down, only the connecting rod 58d that is not connected to the piston hangs downward. Then, place the other case 33d from below, join the two cylinder blocks so that the small end of the connecting rod 58d hangs down into the previously fitted piston 56d, and temporarily connect them with bolts. . At this time, the small end hole of the hanging connecting rod 58d approximately coincides with the piston hole which is aligned with the side hole 55, so when the piston 57 is inserted from the side hole 55 into the piston pin hole, the tip of the piston pin 57 It abuts near the small end hole of the connecting rod 58d. At this time, the small end hole and piston pin are each chamfered, so
Even if there is some misalignment between the two, the piston pin 5
When 7 is pressed strongly, the piston 56d moves into the cylinder hole 34.
The piston pin 57 is automatically aligned by sliding inside the piston pin 57.
fits into the small end hole. In Fig. 6, only two cylinders facing each other were explained, but if there are two cylinders facing each other,
Of course, it is also possible to assemble a total of four engines in the same manner.

When the engine 6 assembled in this manner is started, lubricating oil is supplied to the cylinder hole 34, and the sliding portion of the piston 56 is lubricated with this lubricating oil. Then, the lubricating oil is scraped out from the cylinder hole 34 by the oil scraper ring of the piston 56, and the oil is scraped out from the cylinder hole 34.
It will be adjusted from 4 onwards. At this time, a portion of the lubricating oil is directly applied to the input and output shafts 47 and 48 of the transmission located below the cylinder, the transmission gear (not shown), and the like. That is, the transmission is lubricated with the lubricating oil dripped from the cylinder.

〔Effect of the invention〕

As described above, the present invention provides a multi-cylinder water-cooled engine for a motorcycle equipped with a plurality of cylinders having cylinder axes extending in the horizontal direction of the vehicle body, in which each cylinder is connected to a half-split case forming one half of a crank chamber and a cylinder. It is formed by a cylinder block consisting of
Each cylinder block is connected to each other in a half-split case to form a crank chamber, and an intake hole and an exhaust hole are provided above and below the cylinder head of the cylinder, and the crank chamber housing the crankshaft and the cylinder of the cylinder are connected to each other. A transmission room is arranged below and adjacent to them, and the input and output shafts of the transmission, which are parallel to the crankshaft, are housed in this transmission room so that both are at approximately the same height. An exhaust muffler connected to the exhaust hole of the cylinder head via an exhaust pipe is disposed on the bottom wall side of the transmission room, and the exhaust pipe is suspended along the vertical wall of the transmission room on the cylinder head side. In horizontally opposed engines or V-type engines, the number of large parts is reduced compared to those in which the crankcase and cylinder are prepared separately. Therefore, it is possible to increase the strength of the engine, and also to reduce the weight of the engine and the associated cost.

In addition, the transmission chamber is located below and adjacent to the crank chamber and the cylinder of the cylinder, and the input and output of the transmission are housed in this chamber, so the lubricating oil is scraped out from the cylinder hole by the piston. The oil enters and applies directly to the output shaft and gears on this shaft, lubricating them, improving lubricity and
Manufacturing costs can be kept low by omitting lubricating oil passages and piping.

Furthermore, in addition to the cylinder axes extending horizontally, the transmission chamber is located below and adjacent to the cylinders, so that the input and output shafts parallel to the crankshaft are located at approximately the same height. Since the transmission is retracted, the vertical dimensions of the transmission are reduced, and the cylinder axis is horizontal, so the entire engine is lowered and the center of gravity of the vehicle is lowered. Therefore, maneuverability is improved.

Furthermore, the exhaust muffler is located below the transmission compartment and is connected via an exhaust pipe to the exhaust hole provided on the underside of the cylinder head. Sufficient cooling can be achieved by the wind flowing from the front to the rear.

In addition, a transmission chamber adjacent to the crank chamber and the cylinders is arranged below them, and the exhaust pipe is suspended along the vertical wall of the transmission chamber on the cylinder head side. Since the exhaust pipe is used to connect the exhaust muffler located at the cylinder head with the exhaust hole of the cylinder head, the exhaust pipe and exhaust muffler are close to each other in the transmission room, and there is no dead space, resulting in a compact engine. . Furthermore, even though the transmission room, exhaust pipe, and exhaust muffler are close to each other in this way, the engine is a water-cooled engine with a water jacket around the cylinder hole, and the transmission is located adjacent to the lower part of the cylinder. Due to this relationship, the lubricating oil that scatters inside the transmission chamber due to the rotation of the input and output shaft gears adheres to the cylinder, and since the cylinder with a water jacket functions as a water-cooled oil cooler, the lubricating oil inside the transmission chamber is There is no problem that the lubricity deteriorates due to overheating due to exhaust heat.

[Brief explanation of drawings]

Fig. 1 is a side view of a motorcycle equipped with a multi-cylinder water-cooled engine according to the present invention, Fig. 2 is a partially cutaway plan view of the engine, Fig. 3 is a cross-sectional view taken along the - line, and Fig. 4 is - Line sectional view, Figure 5 is -
6 is a process diagram showing a method of assembling the engine, and FIG. 7 is a sectional view taken along the line -- in FIG. 3. 6... Engine, 21... Crank chamber, 22... Front cylinder, 23... Rear cylinder, 32... Front case, 33... Rear case, 34... Cylinder hole, 35... Cylinder head, 55... Side hole.

Claims (1)

[Claims] 1. In a multi-cylinder water-cooled motorcycle engine equipped with a plurality of cylinders having cylinder axes extending in the horizontal direction of the vehicle body, each cylinder is formed of a cylinder block consisting of a cylinder and a half-split case forming half of a crank chamber. Each cylinder block is connected to each other in a half-split case to form a crank chamber, and an intake hole and an exhaust hole are provided above and below the cylinder of the cylinder, and a crank chamber for housing the crankshaft and a cylinder of the cylinder are provided. A transmission chamber is disposed below and adjacent to the transmission chamber, and the input and output shafts of the transmission parallel to the crankshaft are housed in the transmission chamber so that both are at approximately the same height, An exhaust muffler connected to the exhaust hole of the cylinder head via an exhaust pipe is disposed on the bottom wall side of the transmission room, and the exhaust pipe is suspended along the vertical wall of the transmission room on the cylinder head side. A multi-cylinder water-cooled engine for motorcycles that is characterized by: