JPS6128814B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vehicle engine equipped with an intermediate shaft interposed between a crankshaft and a transmission.

In engines used in motorcycles, a transmission is integrally incorporated, and the crankcase is configured to serve as the transmission case. As such engines become larger in displacement, their length and width increase. In a motorcycle, the entire vehicle body is tilted when turning, but as the width of the engine increases, the angle at which the vehicle body can tilt, that is, the bank angle becomes smaller. For this reason, it is desirable that the engine width be as narrow as possible, and that the left and right bank angles be approximately the same. In order to meet such demands, there are engines in which an intermediate shaft is interposed between the crankshaft and the transmission. That is,
If there is no intermediate shaft, the rotation of the crankshaft must be directly transmitted to the main shaft of the transmission, but since this main shaft is equipped with a group of transmission gears in its center, the rotation of the crankshaft is transmitted directly to one end of the main shaft. This is why the transmission protrudes to one side of the engine, increasing the width of the engine. By transmitting rotation through the intermediate shaft, it is possible to lay out the transmission so that it is aligned with the centerline of the engine, without having the transmission protrude to one side of the engine.

On the other hand, in conventional motorcycle engines, such an intermediate shaft is disposed on the mating surface of the transmission case. In conventional engines, the main shaft, countershaft, and crankshaft of the transmission are pivotally supported on this mating surface, which means that the length in the direction perpendicular to the engine crankshaft increases. For this reason, in motorcycles where the mounting space for the engine is severely limited, it becomes difficult to mount the engine, and the wheelbase has to be widened.

The present invention has been made in view of these disadvantages, and an object of the present invention is to provide a vehicle engine whose length in the direction perpendicular to the crankshaft can be shortened. To achieve this objective, the crankshaft is disposed above the mating surface of the transmission case, and the intermediate shaft is disposed below the mating surface. The present invention will be explained in detail below based on the drawings.

FIG. 1 is a side view of a motorcycle to which an embodiment of the present invention is applied, FIG. 2 is a longitudinal sectional side view of the engine, and FIG. 3 is a sectional view of the engine along the line . In FIG. 1, reference numeral 1 indicates a frame;
This frame 1 includes a steering head pipe 2, a tank rail 3, and a side tube 4. 5 is the front fork, and 6 is the front wheel. 7
8 is a rear wheel, and 8 is a rear arm that holds this rear wheel 7. Note that this vehicle employs a shaft drive system, and a drive shaft (not shown) is inserted through the left arm of the pair of left and right arms of the rear arm 8. This rear arm 8 is pivotally supported on the frame 1 by a support shaft 9. Reference numeral 10 denotes a water-cooled V-type four-cylinder engine, which is mounted on the side tube 4 so as to be suspended from the left and right sides. This engine 10
is equipped with banks 11 and 12 that are inclined in the front and rear direction,
Each bank 11, 12 accommodates two cylinders. 13 is an intake pipe, each bank 11,1
2 is provided approximately vertically on the inner surface of each cylinder for each cylinder. The upper part of this intake pipe 13 is connected to a connecting box (not shown) located inside a fuel tank 14. Reference numeral 15 denotes an air cleaner, which is suspended downward from this connection box. Reference numeral 16 denotes a sound deadening box, which is disposed below the engine 10.
Exhaust gas is guided to this muffling box 16 through exhaust pipes 17 and 18. The exhaust pipe 17 passes from the outer surface of the bank 11 in front of the engine 10, and the exhaust pipe 18 passes from the outer surface of the bank 12 between the support shaft 9 and the rear wheel 7, and is connected to the muffling box 16. ing. A pair of left and right muffling tubes 19 are connected to this muffling box 16. In the figure, 20 is a radiator.

Next, the engine 10 will be explained based on FIGS. 2 and 3. This engine 10 is a two-camshaft overhead four-stroke engine, and its crankcase is integrally formed with a transmission case 21. The transmission case 21 is divided by a case mating surface A into an upper case 21a and a lower case 21b. Upper case 21a
The crankshaft 22 is supported above the mating surface A. That is, the crankshaft 22 is pivotally supported at three points, and ribs 23 are formed on the upper case 21a that extend in the longitudinal direction of the vehicle body in correspondence with this central bearing. A notch 24 is provided, and a crankshaft 22 is pivotally supported within this notch 24. Of the bearing parts of the crankshaft 22, the central bearing part is supported between a notch 24 of the rib 23 and a bearing member 25 fixed to the notch 24. In addition, the other left and right bearing parts are the upper case 21.
It is pivotally supported between a notch provided in the left and right side walls of a and a projecting wall provided in the lower case 21b, which will be described later, so as to fit into the notch.

26 is an intermediate shaft, and this intermediate shaft 26 is supported below the mating surface A. That is, a pair of through holes 2 are formed in the left and right side walls of the lower case 21b.
7 is provided, and an intermediate shaft 26 inserted therein is pivotally supported via a needle bearing. A gear 28 is spline-coupled to the left protrusion of the intermediate shaft 26, and a gear 29 that is key-coupled to the crankshaft 22 meshes with the gear 28. The gear 28 is configured to elastically transmit rotation via a coil spring 30 in order to absorb torque fluctuations of the crankshaft 22 caused by intermittent explosions in each cylinder. 31 is a variable speed drum;
At a position substantially coaxial with the outer periphery of the intermediate shaft 26,
It is rotatably held by a drum holding member 32. This drum holding member 32 will be described later. The speed change drum 31 has three speed change cam grooves 33.
is formed, and the shift fork 34 that engages with this cam groove 33 is moved left and right by the rotation of the shift drum 31, and this movement changes the meshing of the shift gear group to be described later, thereby changing the speed.

Reference numerals 35 and 36 are a main shaft and a sub-shaft that respectively hold the transmission gear group, and the main shaft 35 is connected to the mating surface A.
The secondary shaft 36 is supported pivotally on both left and right walls of the lower case 21b. Rotation is transmitted to the main shaft 35 via a gear 37 fixed to the right protrusion of the intermediate shaft 26 and a wet multi-plate clutch 38 held on the main shaft. Furthermore, this crank 38
is brought into the cutoff state by pushing in the left protruding end of the push rod 39 passing through the main shaft 35 by rotation of the push lever axle 40.
As described above, the meshing of the transmission gears held on the main shaft 35 and the subshaft 36 changes as the transmission fork 34 moves with the rotation of the transmission drum 31, and the transmission ratio changes. 41 is the output shaft;
It is pivotally supported by the mating surface A at the rear of the main shaft 35. The right end of this output shaft 41 is splined to a gear 42 . In other words, this gear 4
2 integrally has a cylindrical portion 42a, and this cylindrical portion 42a is pivotally supported by two bearings, and the right end of the output shaft 41 is spline-coupled to this cylindrical portion 42a. Note that this output shaft 41 is connected to a gearbox 43.
The gear box 43 is assembled into the gear 4 so that its output end 41 is located on the mating surface A.
It is coupled to the second cylindrical portion 42a. The gearbox 43 includes a drive shaft 44 orthogonal to the output shaft 42,
Rotation is transmitted between the output shaft 42 and the drive shaft 44 through a bevel gear 45. This drive shaft 44
is coupled via a constant velocity joint (not shown) to a drive shaft (not shown) inserted through the left arm of the rear arm.

Next, the drum holding member 32 that holds the speed change drum 31 will be explained. FIG. 4 is a cross-sectional view taken along the line 1--2, showing the drive mechanism of the variable speed drum 31. As shown in FIG. An oil pan 45 is coupled to the lower part of the lower case 21b at the mating surface B, a portion of which projects forward, and this projecting portion serves as an oil cooler 46. This oil cooler 46 is provided with cooling fins, and the lubricating oil is cooled when passing between the fins. The drum holding member 32 includes a bottom plate 32a (see FIG. 2) and a bottom plate 32a (see FIG. 2).
A pair of left and right side plates 32b standing up from the left and right sides of 2a.
and an oil pump 47 consisting of a trochoid pump.
It is equipped with This holding member 32 is fixed so that its bottom plate 32a is held between the mating surfaces B. The speed change drum 31 is held on the pair of side plates 32b via bearings, and the speed change drum 31 is arranged coaxially with the intermediate shaft 26 when the bottom plate 32a is held between the mating surfaces B. The dimensions of each part of the holding member 32 are determined. In addition, in FIG. 2, numeral 48 is an oil strainer, 49 is an oil element,
The oil in the oil pan 45 is transferred to the oil strainer 4
The oil is sucked into the oil pump 47 from the oil pump 8 and discharged from the pump 47. After being cooled by the oil cooler 46, the oil is sent under pressure to various parts of the engine via the oil element 49.

Next, the drive mechanism of the variable speed drum 31 will be explained based mainly on FIGS. 4, 5, and 6. FIG. 5 is a side view of this drive mechanism, and FIG. 6 is a side view of the stopper plate. In FIGS. 2, 4, and 5, reference numeral 50 denotes a speed change pedal shaft, which is disposed behind the subshaft 36 so as to pass through the lower case 21b laterally. A gear change pedal (not shown) is fixed to the left side protrusion of the pedal shaft 50. A first lever 51 is fixed to the right side protrusion of the pedal shaft 50. This lever 51 has substantially fan-shaped teeth 51a. This lever 51 has a pin 52 attached to the lower case 21.
It protrudes toward the right side wall of b. On the other hand, a pin 53 is provided on the lower case 21b to protrude toward the lever 51 side. A torsion spring 54 is mounted between the lower case 21b of the pedal shaft 50 and the lever 51,
The two legs of this spring 54 are pin 52 and pin 5.
Holding 3. Therefore, when the gear change pedal (not shown) is depressed or kicked up, the pin 52 rotates together with the lever 51. Therefore, while one leg of the spring 54 remains locked to the pin 53, the other leg remains locked to the pin 53.
It is pushed open by 2. Therefore, the speed change pedal and lever 51 return to the positions shown in FIG.
A second lever 55 is pivotally supported by the lower case 21b, and this lever 55 has fan-shaped teeth 55a that mesh with the gear 51a of the first lever 51.
This lever 55 has a short shaft 56 attached to the lower case 21.
A third lever 57 is provided on this shaft 56 and protrudes toward the b side.
is pivoted. A torsion spring 58 is attached to this shaft 56, and this spring 58 gives the third lever 57 a tendency to return to rotation in the counterclockwise direction in FIG. 59 is a rotating body, which is rotatably supported by the fork guide 60. That is, among the three forks 34, the two forks 34 that move the speed change gear of the subshaft 36 are guided by a fork guide 60 that passes through the side plate 32b of the drum holding member 32. The right end extends through the lower case 21b. A rotating body 59 is pivotally supported on this extending portion. This rotating body 59 has a gear 61 at its left end and six dowel pins 62 at its right end. Note that this rotary body 59 is made to be able to be divided into two on a plane perpendicular to the axis, and a stopper plate 63 is attached to the divided state, and after positioning with a positioning pin 64, they are firmly connected. . As shown in FIG. 5, the dowel pins 62 are installed on the right end surface of the rotating body 59 so as to be arranged at equal intervals on the same circumference. It is locked to a plate 65. The third lever 57 engages with the lower two of the dowel pins 62 from below (see FIG. 5). The stopper plate 63 is formed in a wavy shape with one of the hexagonal corners missing, as shown in FIG. A drum stopper 66 is resiliently pressed against the circumferential surface of the stopper plate 63. That is, a loading portion 67 for a drum stopper 66 is formed on the right side plate 32b of the drum holding member 32, and the drum stopper 66 is loaded therein via a compression spring 68. A gear 69 is fixed to the right end of the speed change drum 31 facing the gear 61, and these gears 61 and 69 mesh with each other.

Therefore, when the gear change pedal (not shown) is depressed or lifted up, the second lever 55 is rotated by the first lever 51. For this reason, the third lever 57
swings in the left-right direction in FIG. 5, and the dowel pins 62 engaged therewith are sequentially fed. Therefore, since the rotating body 59 and the gear 61 also rotate together, the speed change drum 31 is rotated by the gear 69 engaged with the gear 61. As a result, the transmission fork 34 moves left and right, the meshing of the transmission gear group changes, and the transmission ratio changes. Note that the speed change drum 31 is positioned by engagement between a stopper plate 63 and a drum stopper 66.

In this embodiment, the crankshaft shaft 22 and the intermediate shaft 26
Although the shafts are arranged so as to be oriented in the lateral direction of the vehicle body, the present invention may be arranged so that these axes are oriented in the longitudinal direction of the vehicle body. In this case, the width of the engine is reduced, and the bank angle when the vehicle body turns can be increased.

Furthermore, although this embodiment is applied to a motorcycle, the present invention can also be applied to vehicles such as tricycles and four-wheelers, and in this case, the length of the engine can be adjusted to fit the engine mounting space. It is possible to change the width.

As described above, this invention is arranged such that the crankshaft is located above the mating surface of the transmission case, and the intermediate shaft is located below this mating surface, so that the distance between the crankshaft and the intermediate shaft is The horizontal distance perpendicular to these axes is reduced even if the values are the same. Therefore, if the engine is mounted with the crankshaft facing sideways to the vehicle body, the length of the engine in the longitudinal direction will be shortened, and if this engine is applied to a motorcycle, the wheelbase will be significantly increased. It is possible to mount a large multi-cylinder engine without any problems, and the severely limited engine mounting space can be used effectively. Note that when this invention is applied, the vertical distance between the crankshaft and the intermediate shaft increases, so when this engine is mounted on a motorcycle, the center of gravity of the engine becomes slightly higher. However, motorcycles equipped with this type of large engine have very good running stability, so moving the center of gravity upward to this extent has no effect at all, and in fact improves maneuverability when turning. effective.

[Brief explanation of the drawing]

Fig. 1 is a side view of a motorcycle to which an embodiment of the present invention is applied, Fig. 2 is a longitudinal sectional side view of the engine, Fig. 3 is a sectional view of the engine along the line 1, and Fig. 4 is a diagram of the speed change drum. Showing the drive mechanism
Line sectional view, Figure 5 is a side view of this drive mechanism, Figure 6 is a side view of this drive mechanism.
The figure is a side view of the stopper plate. DESCRIPTION OF SYMBOLS 10...Engine, 22...Crankshaft, 26...Intermediate shaft, A...Transmission case mating surface.

Claims (1)

[Claims] 1. In a vehicle engine equipped with an intermediate shaft interposed between a crankshaft and a transmission, the crankshaft is positioned above a case mating surface of the transmission,
Furthermore, the vehicle engine is characterized in that the intermediate shafts are each disposed below the mating surface.