JP5650608B2 - Kick starter for internal combustion engine for small vehicle - Google Patents

Description

  The present invention relates to a kick starter for an internal combustion engine for a small vehicle that can be downsized and has a simple structure.

In a conventional internal combustion engine for a small vehicle, for example, as shown in Patent Document 1 below, when a kick starter is provided, the kick shaft is disposed in an empty space away from the crankshaft, and a plurality of gears are used. I try to drive it.
In the case of the one disclosed in Patent Document 1, a kick starting rotational force is transmitted from a starter drive gear of a kick shaft to an idle gear of a counter shaft, and a starter driven gear and a primary driven gear attached to a multi-plate clutch provided on the main shaft. Is transmitted to the primary drive gear of the crankshaft, and the crankshaft is rotationally driven.
In this way, if a transmission path and arrangement structure for transmitting kick starting rotational force via gears with a plurality of shafts are adopted, the number of parts increases, such as the addition of gears, and the gear structure becomes complicated. Since the distance between the crankshaft and the kick shaft is increased, the internal combustion engine may be increased in size.
In addition, since the transmission path is long, the friction loss is large. The torque at the time of kickback (kickback) increases and the gear strength needs to be increased. Due to the use of a multi-plate clutch, problems such as difficulty in mounting in an internal combustion engine that also uses a centrifugal clutch have arisen.

Japanese Patent No. 4367948 (FIGS. 1 and 2)

  In view of the above-described prior art, the present invention needs to shorten the transmission path from the kick shaft to the crankshaft, enable downsizing of the internal combustion engine, reduce friction loss, and increase gear strength more than necessary. Accordingly, it is an object of the present invention to provide a kick starter for an internal combustion engine for a small vehicle that can be simplified in the number of transmission gears and can be applied to an internal combustion engine that also uses a centrifugal clutch.

  In order to solve the above problems, the invention according to claim 1 is a crankshaft rotatably supported by a crankcase, and a centrifugal shaft provided at one end of the crankshaft and rotating integrally with the crankshaft. An output of the kick starter in a small vehicle internal combustion engine comprising a filter and a kick starter that is provided in the vicinity of the crankshaft and transmits a rotational driving force input from the outside to the crankshaft from an output unit A kick starter for an internal combustion engine for a small vehicle, characterized in that a kick start driven gear that meshes with a kick start drive gear that constitutes a portion is provided integrally with the centrifugal filter.

  According to a second aspect of the present invention, in the kick starter for an internal combustion engine for a small vehicle according to the first aspect, the centrifugal filter has a bowl-shaped filter case, and the kick case is formed on an outer peripheral wall of the filter case. The starter driven gear is integrally molded.

  According to a third aspect of the present invention, in the kick starter for an internal combustion engine for a small vehicle according to the second aspect, a lid member that closes the opening of the cavity of the filter case is attached to the outer peripheral wall of the filter case. A boss portion of the fastening member is included.

  A fourth aspect of the present invention is the kick starter for an internal combustion engine for a small vehicle according to any one of the first to third aspects, wherein the kick starter is in a vehicle-mounted state of the internal combustion engine for the small vehicle. The crankcase is disposed near the front of the crankshaft.

  The invention according to claim 5 is a kick starter for an internal combustion engine for a small vehicle according to any one of claims 1 to 4, wherein the internal combustion engine for a small vehicle has an electric starter by a starter motor, The electric starter and the kick starter are arranged on the left and right sides of the small vehicle internal combustion engine.

  According to a sixth aspect of the present invention, in the kick starter for an internal combustion engine for a small vehicle according to the fifth aspect, the starter motor is exposed on the front surface of the crankcase, and the kick starter is It is provided so as to protrude forward of the crankcase, and is arranged so as to overlap a part of the starter motor in a side view.

  The invention according to claim 7 is the kick starter for an internal combustion engine for a small vehicle according to claim 5 or 6, wherein a hanger boss for attaching the internal combustion engine for the small vehicle to the body frame is the crank. The case is provided above the starter motor and the kick starter.

  The invention according to claim 8 is the kick starter for an internal combustion engine for a small vehicle according to claim 7, wherein the hanger boss is fastened to a gusset extending from the body frame, and the kick starter and the starter It is characterized in that the motor is disposed in the front descending order in order in order to avoid the gusset.

  A ninth aspect of the present invention provides the kick starter for an internal combustion engine for a small vehicle according to any one of the fifth to eighth aspects, wherein an amount of oil stored in the internal combustion engine for the small vehicle is provided. And a cap portion of the level gauge is disposed in the crankcase above the centrifugal filter and the kick starter.

According to the kick starter for an internal combustion engine for a small vehicle according to the first aspect of the present invention, the centrifugal filter rotates concentrically with the crankshaft, and the kick starter gear integrally formed with the centrifugal filter is provided with the kick starter. Since the kick start rotational force is input directly from the kick start drive gear which is the output of the kick start device, the kick start device can be brought as close as possible to the crankshaft, and the distance between the kick shaft and the crankshaft The internal combustion engine for small vehicles (hereinafter simply referred to as “internal combustion engine”) can be reduced in size.
In addition, since the transmission path from the kick shaft to the crankshaft is short, friction loss can be reduced, and it is not necessary to increase gear strength more than necessary, and the number of transmission gears can be reduced and gears can be simplified. Therefore, the present invention can be applied to an internal combustion engine that uses a centrifugal clutch.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, since the kick start driven gear is formed integrally with the centrifugal filter, the number of parts can be reduced.

  According to the invention of claim 3, in addition to the effect of the invention of claim 2, since the boss portion of the fastening member is included in the outer peripheral wall of the filter case of the centrifugal filter, the wall thickness of the outer peripheral wall is thicker. A portion is formed, and a decrease in strength when the kick start driven gear is formed is suppressed.

  According to the invention of claim 4, in addition to the effect of the invention of any one of claims 1 to 3, the kick arm is disposed in front of the crankshaft so that the kick arm is within the longitudinal length of the internal combustion engine. The internal combustion engine including the kick arm is reduced in size. In addition, the kick starter is prevented from hindering the driver's stepping while riding the vehicle.

  According to the invention of claim 5, in addition to the effects of the invention of any one of claims 1 to 4, the electric starter and the kick starter are arranged separately on the left and right of the internal combustion engine. Is efficiently arranged, and the internal combustion engine can be further reduced in size.

  According to the invention of claim 6, in addition to the effect of the invention of claim 5, since the starter motor and the kick starter projecting forward of the crankcase are arranged so as to partially overlap in a side view, the starter motor And the kick starter are close to each other, further reducing the size of the internal combustion engine.

  According to the invention of claim 7, in addition to the effect of the invention of claim 5 or claim 6, the starter motor and the kick starter are disposed below the hanger boss of the crankcase. The position of the center of gravity is kept low, and the internal combustion engine is attached to the upper side of the crankcase, so that the internal combustion engine is stably and firmly fixed to the body frame.

  According to the invention of claim 8, in addition to the effect of the invention of claim 7, since the kick starter and the starter motor are arranged in a descending order in that order avoiding the gusset, the gusset is mounted in the vehicle mounted state of the internal combustion engine. The kick starter and the starter motor can be maintained without being interrupted.

  According to the invention of claim 9, in addition to the effect of the invention of any of claims 5 to 8, the cap portion of the level gauge is provided in the crankcase above the centrifugal filter and the kick starter, Interference between the level gauge, the centrifugal filter, and the kick starter in the gauge removal direction is suppressed, and maintenance is improved.

1 is a right side view of a motorcycle according to an embodiment of the present invention. It is a right view of the internal combustion engine for small vehicles which concerns on this embodiment. FIG. 3 is a cross-sectional development view of the small vehicle internal combustion engine of the present embodiment as viewed in the direction of arrows III-III in FIG. 2. FIG. 4 is a cross-sectional development view of the internal combustion engine for a small vehicle according to the present embodiment as viewed in the direction of arrows IV-IV and IV-IV ′ in FIG.

A kick starter for an internal combustion engine for a small vehicle according to an embodiment of the present invention will be described below with reference to FIGS.
In the description of the present specification and the claims, the directions such as front, rear, left, right, up, down, and the like are as follows. Follow the direction of the vehicle. In the figure, arrow FR indicates the front of the vehicle, LH indicates the left side of the vehicle, RH indicates the right side of the vehicle, and UP indicates the upper side of the vehicle.

  As shown in FIG. 1, a body frame 2 of a motorcycle 1 according to this embodiment as a small vehicle supports a front fork 11 that pivotally supports a front wheel 3 at a lower end portion via a steering stem 12 so as to be steerable. A pair of left and right head pipes 21, and a pair of left and right slopes 22a extending slightly rearward from the head pipe 21, and a rear half slope 22b extending rearwardly from the rear end of the front half slope 22a with a steeper slope than the front half slope 22a. The main pipe 22, a pair of left and right down pipes 23 that are inclined at a steeper angle than the front half inclined part 22a of the main pipe 22 and extend rearwardly downward from the head pipe 21, and the rear part of the main pipe 22 from the lower part of the latter inclined part 22b A pair of left and right rear pipes 24 extending upward, and a connecting pipe 25 that connects a rear end of the front half inclined portion 22a of the main pipe 22 and an intermediate portion of the rear pipe 24 are provided.

In FIG. 1, 13 is a steering handle attached to the upper portion of the steering stem 12, 14 is a front fender, and 15 is a rear fender.
Reference numeral 16 denotes a main stand, reference numeral 17 denotes a kick arm described later, and reference numeral 17a denotes a kick pedal attached to the kick arm 17 so as to be freely laid down.

An air-cooled single-cylinder four-stroke cycle internal combustion engine (hereinafter simply referred to as “internal combustion engine”) 4 is supported on the body frame 2 at the lower part of the rear half inclined part 22 b of the main pipe 22 and the lower part of the down pipe 23. To be mounted.
A fuel tank 18 is mounted on the front half inclined portion 22a of the main pipe 22 of the body frame 2 above the internal combustion engine 4 and is supported by the rear pipe 24 of the body frame 2 behind the fuel tank 18. Thus, a tandem type riding seat 19 is disposed.

Referring also to FIG. 2, the internal combustion engine 4 is coupled to a crankcase 40 that rotatably supports a crankshaft 41 having an axis along the vehicle width direction in a vehicle-mounted state, and a front upper portion of the crankcase 40. A cylinder block 42 that tilts and rises upward, a cylinder head 43 that is coupled to the upper end of the cylinder block 42, and a cylinder head cover 44 that is coupled to the upper end of the cylinder head 43 are provided.
A plurality of cooling fins 42 a arranged vertically are provided on the outer surface of the cylinder block 42, and a plurality of cooling fins 43 a arranged vertically are provided on the outer surface of the cylinder head 43.

  A crankcase 40 that forms the lower part of the internal combustion engine 4 is connected to a transmission case 50 that extends rearward. The transmission 5 for shifting the rotational power from the crankshaft 41 is connected to the mission case 50. The main shaft 51 and the counter shaft 52 of the transmission 5 oriented parallel to the crankshaft 41 are rotatably supported by the transmission case 50.

On the right end side of the main shaft 51, a multi-plate clutch 53 that connects and disconnects the rotational power transmitted from the crank shaft 41 to the main shaft 51 is provided on the coaxial core, and is provided on the main shaft 51 and the counter shaft 52. Transmission is performed by a transmission gear group (not shown), and rotational power is transmitted to the counter shaft 52.
The counter shaft 52 includes a drive sprocket 54 to be described later on the left end side, and serves as an output shaft of the power unit 5. 1 and 2, the main shaft 51, the counter shaft (output shaft) 52, and the multi-plate clutch 53 are shown only at the center position.

In the transmission case 50, a change spindle 55 and a change drum 56 of the transmission 5 for changing the combination of the transmission gear groups described above are supported in parallel with the crankshaft 41 (see FIG. 4).
An AC generator 57 is provided coaxially on the left end side of the crankshaft 41, and a later-described lubricating oil centrifugal filter 6 is provided coaxially on the right end side (see FIG. 4).

  As shown in FIG. 1, the front end of a swing arm 26 that pivotally supports the rear wheel 7 at the rear end is swingable via a support shaft 27 at the lower portion of the rear half inclined portion 22 b of the main pipe 22 of the body frame 2. A rear cushion unit 28 is provided between the rear pipe 24 of the vehicle body frame 2 and the rear part of the swing arm 26.

  A drive sprocket 54 fixed to the projecting end portion of the output shaft 52 from the transmission case 50 and the axle of the rear wheel 7 so that rotational power from the output shaft (counter shaft) 52 is transmitted to the rear wheel 7. An endless drive chain 71 is wound around a driven sprocket 70 provided on 7a.

As shown in FIG. 2, an intake port 45 is provided on the rear side surface of the cylinder head 43, and the intake port 45 is opened to an intake flange 43 b provided integrally with the cylinder head 43.
An intake system 30 is connected to the intake flange 43b. The intake system 30 is connected to an air cleaner 31 disposed below the front portion of the passenger seat 19 as shown in FIG. 1, and an upstream end is connected to the air cleaner 31. A carburetor 32 as intake air amount adjusting means, and an intake pipe 33 connecting the downstream end of the carburetor 32 and the intake flange 43b.

An exhaust port 46 is provided on the front side surface of the cylinder head 43, and the exhaust port 46 is opened to an exhaust flange 43 c provided integrally with the cylinder head 43.
An exhaust system 35 is connected to the exhaust flange 43c. The exhaust system 35 is disposed below the internal combustion engine 4 and an exhaust pipe 36 extending downward from the front side surface of the cylinder head 43, as shown in FIG. And a catalytic converter 37 connected to the downstream end of the exhaust pipe 36 and an exhaust muffler 38 connected to the downstream end of the catalytic converter 37 and disposed on the right side of the rear wheel 7.

FIG. 3 is a cross-sectional development view of the main part of the internal combustion engine 4 of the present embodiment, as viewed in the direction of arrows III-III in FIG.
The internal combustion engine 4 of the present embodiment includes a centrifugal filter 6 in order to obtain a purified oil by separating solid matter such as dust mixed in lubricating oil (hereinafter simply referred to as “oil”).

As shown in FIG. 3, the crankcase 40 is a left-right split system, and includes a left crankcase 40L and a right crankcase 40R. The right crankcase 40R is covered with a right crankcase cover 47R on the right side.
The crankshaft 41 includes a left crankshaft 41L and a right crankshaft 41R, and is integrated via a crankpin 48.
The crankshaft 41 is rotatably supported on the crankcase 40 by a left ball bearing 49L and a right ball bearing 49R.

A cylinder block 42 and a cylinder head 43 are overlapped on the upper part of the crankcase 40 and fastened and connected by a stud bolt 40a. A piston (not shown) connected to the crankpin 48 via a connecting rod 58 is connected to the cylinder block. Slide in the cylinder hole in 42.
Below the crankcase 40, an oil pan 60 and a strainer 61 are provided.

  A primary drive gear 63 is provided on the right crankshaft 41R so as not to rotate relative to the right ball bearing 49R by a key 64 with a sleeve 62 interposed therebetween. The primary drive gear 63 meshes with a primary driven gear (not shown) of a multi-plate clutch 53 provided at the right end portion of the main shaft 51 of the transmission 5.

Adjacent to the primary drive gear 63, on the right end side of the right crankshaft 41R, a filter case 65 having a bowl shape of the centrifugal filter 6 is provided by spline fitting to the right crankshaft 41R.
The filter case 65 includes a hollow portion 65a that is surrounded by the outer peripheral wall 65b and opens rightward in the axial direction. A nut 67 is provided via a washer 66 on the right crankshaft 41R located in the hollow portion 65a, and the inner ring of the filter case 65, the primary drive gear 63, the sleeve 62, and the right ball bearing 49R is tightened. The right crankshaft 41R is fixed.

On the outer peripheral wall 65b of the filter case 65, a boss portion 65c for a bolt (a “fastening member” of the present invention) 68 for attaching a lid member 69 that closes the opening of the cavity portion 65a is formed. The opening of the cavity 65a is closed by the plate-shaped lid member 69 thus formed.
Note that a kick start driven gear 99 described later is integrally formed on the outer peripheral wall 65b of the filter case 65. However, since the outer wall 65b includes the boss portion 65c, the outer peripheral wall 65b is thicker. A part is formed and the strength reduction of the outer peripheral wall 65b is suppressed.

A shaft hole 69a through which the crankshaft 41 passes is provided at the center of the lid member 69. A minute clearance is provided between the shaft hole 69a and the crankshaft 41, and oil leakage from the clearance is prevented while facilitating the assembly of the centrifugal filter. An oil seal, an O-ring, or the like can be disposed between the shaft hole 69a and the crankshaft 41 to further prevent oil leakage.
In addition, an annular groove may be provided on the end surface of the filter case 65, and an O-ring may be interposed between the filter member 65 and the lid member 69 to further prevent oil leakage.

  The shaft end of the right crankshaft 41R is rotatably inserted into the inner recess 47Ra of the right crankcase cover 47R, and the filter case 65 and the lid member 69 rotate together with the right crankshaft 41R. A portion surrounded by the member 69 and the right crankshaft 41R is a centrifugal separation chamber 6a.

An oil pump 75 is provided below the right crankshaft 41R. An oil pump driven gear 77 is provided on the oil pump shaft 76 of the oil pump 75 and meshes with the primary drive gear 63.
A pump case 78 of the oil pump 75 is provided on an annular member 79 surrounding the right crankshaft 41R, and the annular member 79 is attached to the right crankcase 40R via an annular plate member 80.

The suction port 81 of the oil pump 75 is provided in the lower part of the oil pump 75 and communicates with the oil pan 60 via the suction passage 82 and the strainer 61.
The discharge port 83 of the oil pump 75 is provided in the upper part of the oil pump 75, and is connected to the oil passage 84 in the right crankcase cover via a discharge oil passage (not shown). The oil passage 84 in the right crankcase cover communicates with the inner recess 47Ra of the right crankcase cover 47R.

A shaft end hole 86 and a center hole 87 are formed on the right crankshaft 41R on the crankshaft centerline X without continuing each other.
The right end of the shaft end hole 86 opens into the inner recess 47Ra of the right crankcase cover 47R, and an oil supply hole 86a that communicates from the shaft end hole 86 to the centrifugal separation chamber 6a of the filter case 65 is provided.

The center hole 87 is provided with an oil outflow hole 87a that communicates with the center hole 87 from the centrifugal separation chamber 6a of the filter case 65.
An end of the center hole 87 on the center side of the internal combustion engine communicates with the oil passage 88 in the crank pin. The centrifugal filter 6 of the present embodiment includes a filter case 65, a lid member 69, and an oil supply hole 86a and an oil outflow hole 87a provided in the crankshaft 41.

In the centrifugal filter 6 as described above, the oil pump 75 is rotationally driven by the rotation of the crankshaft 41, and the oil stored in the oil pan 60 is sucked into the oil pump 75 through the strainer 61 and the suction passage 82, It is discharged through the oil pump 75.
The oil discharged from the discharge port 83 flows into the shaft end hole 86 of the crankshaft 41 through a discharge oil passage (not shown), an oil passage 84 in the right crankcase cover, and an inner recess 47Ra of the right crankcase cover 47R. The oil is ejected into the centrifugal separation chamber 6a of the centrifugal filter 6 through the oil supply hole 86a.

  The centrifugal separation chamber 6a of the centrifugal filter 6 provided at one end of the crankshaft 41 and rotating integrally with the crankshaft 41 is rotated together with the crankshaft 41, so that solid matter such as dust mixed in the oil is removed. When pressed against the inner peripheral wall 6b of the centrifugal separation chamber 6a, clean oil flows from the oil outlet hole 87a of the crankshaft 41 into the center hole 87 of the crankshaft 41, is sent to the oil passage 88 in the crankpin, and further connected to the connecting rod 58. To the large end 58a and the left and right ball bearings 49L, 49R to lubricate them.

FIG. 4 is a cross-sectional development view of a main part of the internal combustion engine 4 of the present embodiment, taken along arrows IV-IV and IV-IV ′ in FIG. 2.
As shown in FIG. 4, an AC generator 57 is provided at the left end of the left crankshaft 41L, and the AC generator 57 is covered with a left crankcase cover 47L attached to the left crankcase 40L.

The inner stator 57a of the AC generator 57 is fixed to the inner surface of the left crankcase cover 47L, and the outer rotor 57b of the AC generator 57 is fixed to the left crankshaft 41L.
The left crankshaft 41L is rotatably provided with a motor start driven gear 100 on the left side of the left ball bearing 49L. The motor start driven gear 100 is connected to the outer rotor 57b of the AC generator 57 via the one-way clutch 101. Has been.

The left crankcase 40L extends forward from the crankshaft 41, and a starter motor 10a projects from the front surface of the crankcase 40 and is mounted with its rotating shaft 10b parallel to the crankshaft 41.
An intermediate shaft 102 having a large diameter gear 102a and a small diameter gear 102b is rotatably supported in parallel with the crankshaft 41 between the left crankcase 40L and the left crankcase cover 47L. 102a meshes with the pinion gear 10c of the rotating shaft 10b of the starting motor 10a, and the small diameter gear 102b meshes with the motor starting driven gear 100.

  Therefore, in the internal combustion engine 4 of the present embodiment, the driving force of the starting motor 10a is such that the pinion gear 10c, the large diameter gear 102a of the intermediate shaft 102, the small diameter gear 102b, the motor starting driven gear 100, the one-way clutch 101, and the outer rotor of the AC generator 57. An electric starter 10 that is transmitted to the crankshaft 41 via 57b is provided.

On the other hand, the right crankcase 40R and the right crankcase cover 47R extend forward from the crankshaft 41 to form a kick starter chamber 90, and project from the crankcase 40 in front to be provided with a kick starter 9. The kick starter 9 is disposed slightly above the starter motor 10a in a side view so as to overlap a part of the starter motor 10a.
A kick shaft 91 is rotatably supported in parallel with the crankshaft 41 between the right crankcase 40R and the right crankcase cover 47R forming the kick starter chamber 90.

The bearing portion 92 of the kick shaft 91 in the right crankcase cover 47R has a thick cylindrical shape and bulges to the right, and the right end portion 91a of the kick shaft 91 penetrates the right crankcase cover 47R to the right. Protruding.
The base end portion of the kick arm 17 shown in FIG. 1 is fitted to the right end portion 91a. A kick pedal 17a (see FIG. 2) is attached to the tip of the kick arm 17 so as to be able to fall down.

The left end of the kick shaft 91 is pivotally supported by a bearing portion 93 on the right surface of the right crankcase 40R, and a return spring 94 accommodated in the kick starter chamber 90 is wound around the kick shaft 91 adjacent to the bearing portion 93. ing.
One end 94a of the return spring 94 is locked to the kick shaft 91, and the other end 94b is locked to the inner surface of the right crankcase cover 47R. Accordingly, the kick shaft 91 is urged by the return spring 94 so as to return to the operation start position together with the kick arm 17.

  Further, a stopper member 95 is spline fitted to the kick shaft 91 adjacent to the bearing portion 92 in the kick starter chamber 90, and a protrusion 95a of the stopper member 95 is provided on the inner surface of the right crankcase cover 47R. The kick arm 17 biased by the return spring 94 is held at a predetermined operation start position in contact with a projection (not shown).

The kick shaft 91 is provided between a return spring 94 and a stopper member 95, and is provided with a left driven helical gear 96 and a kick start drive gear 97 on the right.
The kick start drive gear 97 is rotatably mounted on the kick shaft 91 and is prevented from moving rightward by a locking portion 91c provided on the kick shaft 91. Further, movement to the left is restricted by a ring or the like.

  Helical outer teeth 91b are engraved on the outer peripheral surface of the kick shaft 91 on the left side of the kick start drive gear 97, and helical inner teeth 96b are engraved on the inner peripheral surface of the driven helical gear 96. It is meshed with helical outer teeth 91b on the outer peripheral surface.

A friction spring 98 having a part of a missing ring is fitted in a groove formed in the outer circumferential surface of the driven helical gear 96 in the circumferential direction, and the driven helical gear 96 is tightened to rotate the driven helical gear 96. Gives friction.
The tip of the handle portion 98a extending outward from the partially missing annular portion of the friction spring 98 is slidably fitted in a left and right groove (not shown) formed on the inner surface of the right crankcase cover 47R. .

On the right side surface of the driven helical gear 96, ratchet teeth 96a are formed to protrude along the periphery.
On the left side surface of the kick start drive gear 97, ratchet teeth 97a that can mesh with the ratchet teeth 96a of the driven helical gear 96 are formed so as to constitute a ratchet mechanism.

  On the other hand, the filter case 65 of the centrifugal filter 6 is provided by spline fitting at the right end of the right crankshaft 41R, and as described above, at the position facing the kick start drive gear 97 at the outer periphery 65b. A kick start driven gear 99 is engraved and integrally molded, and meshes with the kick start drive gear 97.

The kick starter 9 is configured as described above. When the kick pedal 17a is depressed and the kick shaft 91 is rotated against the return spring 94 by the kick arm 17, the helical external teeth rotate integrally with the kick shaft 91. Since the driven helical gear 96 meshed with 91b by the helical internal tooth 96b is prevented from rotating by the frictional resistance in the rotational direction by the friction spring 98, the driven helical gear 96 moves to the right, and its ratchet tooth 96a is kick-started. The driven helical gear 96 and the kick start driving gear 97 rotate together with the kick shaft 91 while meshing with the ratchet teeth 97a of the driving gear 97.
Further, the engagement of the kick start drive gear 97 and the kick start driven gear 99 causes the crankshaft 91 to be forcibly rotated and the internal combustion engine 4 is started.

  When stepping on the kick pedal 17a is stopped and the kick pedal 17a is released, the kick shaft 91 reversely rotates by the return spring 94 and returns to the original operation start position together with the kick arm 17, so that the driven helical gear 96 has its helical inner teeth 96b. And the helical teeth 91b of the kick shaft 91 are moved in the left direction to disengage the ratchet teeth 97a and 96a, and the kick shaft 91 is released from the rotation of the crankshaft 41.

  As described above, the kick starter 9 of the present embodiment is disposed near the front of the crankshaft 41 in the crankcase 40, the kick arm 17 is disposed within the longitudinal length of the internal combustion engine 4, and the kick start is performed. The device 9 and the electric starter 10 are arranged separately on the left and right sides of the internal combustion engine 4, and the internal combustion engine 4 is configured to save space.

The internal combustion engine 4 also has a gusset provided extending from the down pipe 23 of the vehicle body frame 2 by a hanger boss 40b provided on the crankcase 40 above the starter motor 10a and the kick starter 9 slightly above it. It is attached to the vehicle body frame 2 via 29, and the center of gravity is lower than the attachment part of the gusset 23, and it is stably and firmly fixed.
Further, maintenance of the starter motor 10a and the kick starter 9 can be performed without being disturbed by the gusset 29.

  As shown in FIG. 2, an oil level gauge 59 for checking the amount of oil stored inside is inserted into the crankcase 40 above the centrifugal filter 9 and the kick starter 6, and the cap portion 59a is connected to the crankcase. Since it is arranged on the upper part of 40, there is no interference with the centrifugal filter 9 and the kick starter 6 in the gauge removal direction A, and maintenance is easy.

Below, the characteristic of the kick starter of the internal combustion engine for small vehicles of the above-mentioned embodiment will be described collectively.
That is, the internal combustion engine (small vehicle internal combustion engine) 4 includes a crankshaft 41 rotatably supported by a crankcase 40, and a centrifugal filter that is provided at one end of the crankshaft 41 and rotates integrally with the crankshaft 41. 6 and a kick starter 9 that is provided in the vicinity of the crankshaft 41 and transmits a rotational driving force input from the outside to the crankshaft 41 from the kick start drive gear 97, and the kick start drive gear 97 is engaged. A kick start driven gear 99 is provided integrally with the centrifugal filter 6.

Accordingly, the centrifugal filter 6 rotates concentrically with the crankshaft 41, and the kick start driven gear 99 formed integrally with the centrifugal filter 6 is directly connected to the kick start drive gear 97 which is the output portion of the kick start device 9. Since the kick starting rotational force is input, the kick starting device 9 can be brought as close as possible to the crank shaft 41, and the distance between the kick shaft 91 and the crank shaft 41 can be reduced. The internal combustion engine 4 can be downsized.
In addition, since the transmission path from the kick shaft 91 to the crankshaft 91 is short, friction loss can be reduced, it is not necessary to increase the gear strength more than necessary, and the number of transmission gears can be reduced and the gear can be simplified. Since the transmission path does not include the multi-plate clutch 53, the present invention can also be applied to an internal combustion engine that uses a centrifugal clutch.

  Further, since the centrifugal filter 6 has a filter case 65 having a bowl shape, and the kick start driven gear 99 is integrally formed on the outer peripheral wall 65b of the filter case 65, the number of parts can be reduced.

  Further, the outer peripheral wall 65b of the filter case 65 includes a boss portion 65c of a bolt 68 for attaching a lid member 69 that closes the opening of the hollow portion 65a of the filter case 65, so that the outer wall 65b is thicker. , And a decrease in strength when the kick start driven gear 99 is formed is suppressed.

  Further, since the kick starter 9 is disposed near the front of the crankshaft 41 in the crankcase 40 when the internal combustion engine 4 is mounted on the vehicle, the kick arm 17 is disposed within the longitudinal length of the internal combustion engine 4 and the kick arm The internal combustion engine 4 including 17 can be downsized. Further, the kick starter 9 is prevented from hindering the driver's stepping while riding the vehicle.

  Further, the internal combustion engine 4 has an electric starter 10 by a starter motor 10a, and the electric starter 10 and the kick starter 9 are arranged separately on the left and right sides of the internal combustion engine 4, so that the kick starter 9 is efficient. Therefore, the internal combustion engine 4 can be further reduced in size.

  Further, the starter motor 10a is provided so as to be exposed on the front surface of the crankcase 40, and the kick starter 9 is provided so as to protrude in front of the crankcase 40 so as to overlap a part of the starter motor 10a in a side view. Since the starter motor 10a and the kick starter 9 are close to each other, the internal combustion engine 4 can be further downsized.

  Further, the hanger boss 40b for attaching the internal combustion engine 4 to the vehicle body frame 2 is provided above the starter motor 10a and the kick starter 9 in the crankcase 40. Since it is attached on the upper side of the case 40, the internal combustion engine 4 is stably and firmly fixed to the vehicle body frame 2.

  Further, the hanger boss 40b is fastened to the gusset 29 extending from the vehicle body frame 2, and the kick starter 9 and the starter motor 10a are arranged in a descending order in that order avoiding the gusset 29. In the mounted state, the kick starter 9 and the starter motor 10a can be maintained without being interrupted by the gusset 29.

  The internal combustion engine 4 is provided with a level gauge 59 for confirming the amount of oil stored therein, and the cap portion 59a of the level gauge 59 is attached to the crankcase 40 above the centrifugal filter 6 and the kick starter 9. Since they are arranged, interference between the level gauge 59, the centrifugal filter 6 and the kick starter 9 in the gauge removal direction A is suppressed, and the maintainability is improved.

As mentioned above, although the kick starter of the internal combustion engine for a small vehicle according to one embodiment of the present invention has been described, it is needless to say that the present invention includes aspects different from the above embodiments within the scope of the gist of each claim.
For example, the internal combustion engine for a small vehicle is not limited to the air-cooled single-cylinder four-stroke cycle internal combustion engine of the above embodiment, and may be various internal combustion engines having the configuration of claim 1, and the small vehicle is not limited to a motorcycle.

  DESCRIPTION OF SYMBOLS 1 ... Motorcycle (small vehicle), 2 ... Body frame, 4 ... Internal combustion engine ("internal combustion engine for small vehicles" of this invention), 5 ... Transmission, 6 ... Centrifugal filter, 6a ... Centrifugal separation chamber, 6b ... Inside Peripheral wall, 9 ... kick starter, 10 ... electric starter, 10a ... starter motor, 17 ... kick arm, 17a ... kick pedal, 22 ... main pipe, 23 ... down pipe, 29 ... gusset, 40 ... crankcase, 40b ... Hanger boss, 40L ... left crankcase, 40R ... right crankcase, 41 ... crankshaft, 41L ... left crankshaft, 41R ... right crankshaft, 47L ... left crankcase cover, 47R ... right crankcase cover, 50 ... mission case , 51 ... main shaft, 52 ... counter shaft (output shaft), 59 ... level gauge, 59a ... cap portion, 63 ... primary drive gear, 65 ... filter case, 65a ... hollow portion, 65b ... outer peripheral wall, 65c ... Boss portion, 68 ... bolt ("fastening member" of the present invention), 69 ... lid member, 75 ... oil pump, 90 ... kick starter chamber, 91 ... kick shaft, 96 ... driven helical gear, 97 ... kick start drive gear, 99 ... Kick start driven gear

Claims (9)

A crankshaft (41) rotatably supported by the crankcase (40);
A centrifugal filter (6) provided at one end of the crankshaft (41) and rotating integrally with the crankshaft (41);
A small vehicle internal combustion engine (4) provided with a kick starter (9) provided in the vicinity of the crankshaft (41) and transmitting a rotational driving force input from the outside to the crankshaft (41) from an output portion. )
A kick start driven gear (99) meshing with a kick start drive gear (97) constituting an output portion of the kick start device (9) is provided integrally with the centrifugal filter (6). A kick starter for an internal combustion engine for a small vehicle. The centrifugal filter (6) has a bowl-shaped filter case (65),
The kick starter for an internal combustion engine for a small vehicle according to claim 1, wherein the kick start driven gear (99) is integrally formed on an outer peripheral wall (65b) of the filter case (65).   A boss portion (65c) of a fastening member (68) for attaching a lid member (69) for closing the opening of the cavity portion (65a) of the filter case (65) to the outer peripheral wall (65b) of the filter case (65) The kick starter for an internal combustion engine for a small vehicle according to claim 2, wherein   The kick starter (9) is disposed in front of the crankshaft (41) in the crankcase (40) when the small vehicle internal combustion engine (4) is mounted on a vehicle. The kick starter for an internal combustion engine for a small vehicle according to any one of claims 1 to 3. The small vehicle internal combustion engine (4) has an electric starter (10) by a starter motor (10a), and the electric starter (10) and the kick starter (9) are connected to the small vehicle internal combustion engine ( 10). 5. The kick starter for an internal combustion engine for a small vehicle according to any one of claims 1 to 4, wherein the kick starter is arranged in the left-right direction of 4).   The starter motor (10a) is provided so as to be exposed on the front surface of the crankcase (40), and the kick starter (9) is provided so as to protrude in front of the crankcase (40). 6. The kick starter for an internal combustion engine for a small vehicle according to claim 5, wherein the kick starter is disposed so as to overlap a part of the starter motor (10a).   A hanger boss (40b) for mounting the internal combustion engine (4) for the small vehicle to the vehicle body frame (2) is provided by the starter motor (10a) and the kick starter (9) of the crankcase (40). The kick starter for an internal combustion engine for a small vehicle according to claim 5 or 6, wherein the kick starter is provided above.   The hanger boss (40b) is fastened to a gusset (29) extending from the body frame (2), and the kick starter (9) and the starter motor (10a) avoid the gusset (29), 8. The kick starter for an internal combustion engine for a small vehicle according to claim 7, wherein the kick starter is disposed in a descending order in that order.   The small vehicle internal combustion engine (4) is provided with a level gauge (59) for confirming the amount of oil stored therein, and a cap portion (59a) of the level gauge (59) is connected to the centrifugal filter ( The kick starter for an internal combustion engine for a small vehicle according to any one of claims 5 to 8, wherein the kick starter is disposed in the crankcase (40) above the kick starter (6) and the kick starter (9).

Images