JP2726452B2 - Engine cell motor arrangement structure - Google Patents

Description

The present invention relates to an arrangement structure of a starter motor suitable for, for example, a motorcycle engine, and particularly to a height from a road surface to a bottom surface of a crankcase while lowering the center of gravity of the engine. The present invention relates to an arrangement structure of a starter motor capable of increasing a height (hereinafter, referred to as a ground height).

[Conventional technology]

For example, when a starting cell motor is provided in a motorcycle engine, it is generally arranged near a front wall, a top wall, or a bottom wall of a crankcase. However, when it is located near the front wall, the front and rear length of the crankcase becomes longer, and the center of gravity of the engine tends to be biased toward the front. When it is installed near the top wall, the front and rear length of the crankcase and the center of gravity are closer. Although the problem disappears, there is a problem that the center of gravity is raised this time. On the other hand, when it is arranged near the bottom wall, the center of gravity becomes low, and the above problem can be solved.

[Problems to be solved by the invention]

However, when the above cell motor is simply provided near the bottom wall of the crankcase, the cell motor projects downward depending on the layout design, the thickness in the height direction of the crankcase increases, and the height above the ground when mounted on a vehicle is increased. There is a problem of lowering. This is a problem to be solved particularly in the case of a motorcycle whose main purpose is running on uneven terrain.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to provide an engine starter motor arrangement structure capable of securing a sufficient ground clearance while lowering the center of gravity.

[Means for solving the problem]

The present invention relates to a starter motor arrangement structure for an engine having a crankcase divided into upper and lower cases, in which a crankshaft and a transmission auxiliary shaft (drive shaft) are arranged in parallel between divided surfaces of the crankcase, A transmission main shaft (main shaft) having a clutch mounted on a portion thereof is disposed between the crankshaft and the transmission sub-shaft of the upper case, and a starter motor is disposed below the transmission main shaft on the bottom surface of the lower case.

[Action]

According to the starter motor disposition structure according to the present invention, the crankshaft and the transmission sub-shaft are arranged in parallel between the divided surfaces of the crankcase, and the transmission main shaft is arranged above the upper shaft between the two shafts. A space is created below the transmission main shaft. Since the starter is disposed in this space, the starter can be prevented from protruding downward while the starter is disposed on the bottom wall of the crankcase. As a result, the center of gravity can be reduced and the ground clearance can be sufficiently secured.

〔Example〕

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

1 to 6 are views for explaining one embodiment of the present invention.

In the drawing, reference numeral 1 denotes a motorcycle on which the engine of the present embodiment is mounted, and a front fork 4 for supporting a front wheel 3 at a lower end is supported at the front end of a body frame 2 so as to be steerable left and right. A rear arm 6 that pivotally supports the rear wheel 5 at the rear end is pivotally supported vertically at the lower end, and a large fuel tank 7 and a seat 8 are mounted on the upper portion in order from the front. An engine unit 9 is suspended and supported below the front part of the body frame 2.

The engine unit 9 is an air-cooled 4-cycle parallel 2
A cylinder type, a cylinder block 11, a cylinder head 12, and a head cover 13 are stacked on a front portion of an upper surface of a crankcase 10 in a state where the cylinder block 11, the cylinder head 12, and the head cover 13 are inclined forward by approximately 45 degrees with respect to a horizontal plane.

Above the left and right cylinders 11a and 11b of the cylinder block 11, pistons 14a and 14b and concave portions 12 of the cylinder head 12 are provided.
a and 12b, a combustion chamber 14 is formed. The intake and exhaust ports communicating with the combustion chamber 14 have three intake valves 15a and one exhaust valve 1a.
Two 5b are arranged. A driven sprocket 16c is fixed to the right end of the intake cam shaft 16a and the exhaust cam shaft 16b for the intake valve 15a and the exhaust valve 15b when viewed from the rear of the vehicle (the same applies hereinafter).

The pistons 14a, 14b are connected to a pair of crank arm portions 18a, 18b of the crankshaft 18 by connecting rods 17a, 17b, respectively, and a portion between the two crank arm portions 18a, 18b of the crankshaft 18 is a central bearing. The left and right outer portions are supported by left and right bearings 19a and 19b, respectively.

The crankcase 10 has an upper / lower split structure divided into upper and lower cases 23 and 24. The split surface A is inclined so that the front side becomes lower when mounted on a vehicle. Above left, right,
The center bearings 19a to 19c are formed at a portion closer to the front side of the division surface A. A pivot bot portion 24a pivotally supporting the front end of the rear arm 6 is provided at the rear end of the lower case 24.
Are integrally formed.

A drive sprocket is located on the right side of the crankshaft 18
The sprocket 18c and the camshaft 16 are integrally formed.
A cam chain 20 is wound between the driven sprockets 16c of a and 16b. The cam chain 20 is arranged so as to pass through chain case portions 12c, 11c, and 23a which are formed to protrude from the right side wall of the cylinder head 12, the cylinder block 11, and the upper case 23. Behind this cam chain 20, a tensioner
60 is provided, and a chain pressing member of the tensioner 60 is provided.
The lower end of 60a is rotatably supported by a pin 61a.
The upper and lower covers 23 and 24 are located outside the pins 61a.
Are positioned so as to be substantially perpendicular to the axis of the pin 61a, thereby preventing the pin 61a from coming off.

A transmission countershaft 35 is disposed behind the crankshaft 18 between the split surfaces, and a crankshaft 18 of the upper cover 23 is provided.
The transmission main shaft 32 is provided in an upper portion between the transmission and the transmission sub shaft 35. The left and right ends of the transmission main shaft 32 are bearings 32b and 32c.
The transmission countershaft 35 is supported by bearings 35b and 35c, respectively.

A wet multi-plate clutch 33 is mounted on the right end of the transmission main shaft 32, and a reduction gear wheel 33b of the clutch 33 having an outer 33a fixed thereto meshes with a reduction gear 22 fixed to the crankshaft 18. ing. The transmission gears 32a and 35a of the respective stages mounted on the transmission main shaft 32 and the sub shaft 35 are in mesh with each other, thereby forming a constant mesh transmission.

The left end of the transmission countershaft 35 protrudes outward from the left side wall of the crankcase 10, and a sprocket 36 for rear wheel drive is mounted on the protruding portion, between the sprocket 36 and the driven sprocket 5a of the rear wheel 5. Has a transmission chain 37 wound.
A chain cover 38 is provided outside the sprocket 36 so as to cover the sprocket 36, and a case cover 42 is further provided outside the cover 38. Reference numeral 58 denotes a breather cover that opens and closes an assembling opening of a rear balancer shaft and the like, which will be described later, and that constitutes an oil breather.

A front balancer shaft 47 is provided on the lower case 24 in front of the crankshaft 18 and below the dividing plane A, and a rear balancer shaft 48 is provided on the upper case 23 behind the crankshaft 18 and above the dividing plane A. Are arranged in parallel with the crankshaft 18, and a line L connecting the axes of the balancer shafts 47 and 48 is located forward of the axis of the crankshaft 18. The front and rear balancer shafts 47 and 48 have a structure in which a support shaft 50 is inserted into a balancer body 49 and a needle bearing 51 is disposed between the two. Reference numeral 52 denotes a positioning member that regulates the position of the balancer shafts 47 and 48 in the axial direction. In addition, the balancer body 49
Both of the driven gears 47a and 48a fixed to the left end of the gear mesh with the balancer gear 21 fixed to the crankshaft 18 so as to rotate in a direction opposite to the crankshaft 18.

Further, a water pump 5 for circulating cooling water is provided on a portion of the right side wall of the crankcase 10 in front of the chain case portion 23a.
3 are arranged. Further, a pump drive gear 25 is mounted on the right end of the crankshaft 18. Below the pump drive gear 25, a feed pump 26 for supplying lubricating oil from an oil tank (not shown) to the lubrication required parts such as the bearings 19a to 19c and a lubricating oil in an oil pan 28 are provided. A scavenge pump 27 for feeding oil into the oil tank is arranged in parallel in the front and rear of the vehicle, and the pump drive gear 25 is connected to an input gear 26a of the feed pump 26, and the input gear 26a is connected to an input gear 27a of the scan pump 27. They are engaged in sequence.
Reference numeral 29 denotes a strainer housing provided in the oil pan 28, reference numeral 28a denotes a cleaner chamber formed in the oil pan 28 for housing the oil cleaner 31, and reference numeral 30 denotes a cap for opening and closing the cleaner chamber 28a. The strainer housing 29 is located below the weight 49b of the front balancer shaft 47 and the crank arms 18a, 18b. In the housing 29, ribs 29a, 29b are formed upright toward the weight 49b and the crank arm 18a.

A starting cell motor 43 is provided on the bottom surface of the lower case 24 below the transmission main shaft 32, that is, below the crankshaft 18 and the transmission auxiliary shaft 35. The starter 43 is disposed in a portion surrounded by the oil pan 28 and the cleaner chamber 28a, and the rear end thereof is bolted.
At 62, it is fixed to the lower case 24. Also this cell motor
The output shaft 43a of 43 penetrates the lower case 24 and the generator cover 44
And a driving gear 4 mounted on the output shaft 43a.
3b is the left bearing of the crankshaft 18 through the idle gear 45
It is in mesh with a starting gear 46 mounted on a portion outside of 19a via a one-way clutch.

 Next, the operation and effect of this embodiment will be described.

In starting the engine of this embodiment, when a starter button provided on the steering handle is pressed, the starter motor 43 rotates, and this rotation is transmitted to the crankshaft 18 via the idle gear 45, whereby the engine is started. Will be done.

When such a cell motor is arranged, as described above, if the cell motor is arranged on the bottom wall of the crankcase in order to reduce the center of gravity, there is a problem that the motor tends to protrude downward, and the ground clearance cannot be secured. On the other hand, in the present embodiment, the crankshaft 18 and the transmission auxiliary shaft 35 are arranged in parallel between the divided surfaces of the crankcase 10, and the transmission main shaft 32 having a large-diameter clutch is arranged above the two shafts. By the crankshaft
18, an empty space is formed below the speed change sub shaft 35, and the starter motor 43 is disposed in this space. As a result, the starter 43
Can be prevented from projecting downward while the cell motor 43 is disposed on the bottom wall. As a result, the center of gravity can be reduced and the ground clearance can be sufficiently secured.

Further, an oil pan is generally provided on the bottom surface of the crankcase, and depending on the layout design of the oil pan, there is a concern that the above-mentioned cell motor arrangement space becomes narrow. On the other hand, in the present embodiment, a so-called dry sump system in which lubricating oil is circulated between the separately provided oil tank, each lubricating portion, and the oil pan is employed, so that the oil pan 28 can be downsized. it can. As a result, it is possible to avoid the problem that the oil motor pan narrows the cell motor arrangement space realized by devising the arrangement of the crankshaft 18 and the transmission main and sub shafts 32 and 35 described above.

〔The invention's effect〕

As described above, according to the cell motor arrangement structure of the present invention, the crankshaft and the transmission sub-shaft are arranged in parallel between the upper and lower split surfaces of the crankcase, and the transmission main shaft is arranged above the two shafts. Since the starter motor is arranged below the shafts, the starter motor is arranged on the bottom surface of the crankcase so that the center of gravity can be reduced, and there is an effect that the protrusion of the starter motor is prevented from lowering and the ground clearance can be sufficiently secured.

[Brief description of the drawings]

1 to 6 are views for explaining a starter motor arrangement structure according to one embodiment of the present invention. FIG. 1 is a partially sectional left side view of an engine to which the structure is applied, and FIG. FIG. 3 is a bottom view, FIG. 4 is a partial sectional right side view of the engine, and FIG.
Fig. 6 is a left side view of a motorcycle equipped with the engine of the embodiment. In the figure, 9 is an engine unit, 10 is a crankcase, 18 is a crankshaft, 23 and 24 are upper and lower cases, 32 is a transmission main shaft, 33 is a clutch, 35 is a transmission subshaft, 43 is a cell motor,
A is a division plane.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-56-165766 (JP, A) JP-A-55-156256 (JP, U) JP-A-1-61464 (JP, U) Jiko-sho 57- 28169 (JP, Y2)

Claims (1)

(57) [Claims] In a cell motor arrangement structure of an engine having a crankcase divided into upper and lower cases, a crankshaft and a transmission auxiliary shaft are arranged in parallel between divided surfaces of the crankcase, and a clutch is provided at an end. A cell motor arrangement structure for an engine, wherein a transmission main shaft on which is mounted is disposed between the crankshaft and the transmission sub-shaft of the upper case, and a starter motor is disposed below the transmission main shaft on the bottom surface of the lower case.