CN1153867A

CN1153867A - Crankcase structure for four-stroke internal combustion engine

Info

Publication number: CN1153867A
Application number: CN96121021A
Authority: CN
Inventors: 大山隆; 平山周二
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 1995-11-22
Filing date: 1996-11-19
Publication date: 1997-07-09
Anticipated expiration: 2016-11-19
Also published as: CN1087395C; KR970027757A; JP3565298B2; FR2741390B1; TW297078B; KR100216394B1; MY128549A; JPH09144599A; FR2741390A1

Abstract

The invention provides a structure of crankcase of four-stroke internal combustion engine to water-tightly close between a cam chain chamber and a belt type continuously variable transmission chamber by a small number of papers and easily mount/demount a cam chain at maintenance time. In a four-cycle internal combustion engine in which a crankshaft 40 penetrates a partition wall 71 of a crankcase partitioning a cam chain chamber 52 and a belt type continuously variable transmission chamber 70 and a through hole 71a is closed with a seal member 72, the through hole 71a is closed with the circular annular seal member 72 having an external diameter larger than a maximum external diameter in a condition that a cam chain 51 is wound to a cam chain driving sprocket 55 mounted to be fitted to the crankshaft.

Description

The crankcase structure of quartastroke engine

The present invention relates to a kind of quartastroke engine crankcase structure that in valve driving, adopts the cam chain mode, has belt type adjustable speed drive.

In this quartastroke engine, because bent axle is through with the crankcase partition wall that separates of cam chain chamber of belt type adjustable speed drive chamber and use lubricant oil, therefore, in the bent axle through hole of partition wall, to embed sealed member, lubricant oil can not leaked in the belt type adjustable speed drive chamber.

In the special fair 5-47437 communique of Japan Patent, disclosed this structure, in this communique, on the partition wall that cam chain chamber and belt type adjustable speed drive chamber are separated, be formed with large diameter circular hole, the discoideus cover of hollow filled in this circular hole be screwed, allow bent axle pass the through hole of these cover central authorities.

Like this, will close than the bigger through hole of the bent axle diameter of this cover with sealed member.

Therefore, when carrying out the maintenance of internal-combustion engine, owing to cover need be unloaded, and on partition wall, having big opening, the cam chain that could will be wound on the driving sprocket wheel takes out from this opening.

Yet, if the cover that adopts this and partition wall branch to be arranged, and form the mounting structure of screw that this cover is installed etc., can cause the complicated and component number of mechanism to increase.

In need not the internal-combustion engine in the past of this cover, during maintenance cam chain unloaded and can only adopt the crankcase of left and right sides whole body structure method such as divide right and left, very bother during operation.

The present invention in view of the above problems, its objective is provides a kind of parts with seldom in the structure of carrying out the sealing of watertight ground between cam chain chamber and the belt type adjustable speed drive chamber and taking off the quartastroke engine crankcase of chain easily during in maintenance.

In order to finish above-mentioned purpose, the invention provides a kind of quartastroke engine crankcase structure, bent axle runs through the crankcase partition wall that cam chain chamber and belt type adjustable speed drive chamber are separated, this through hole is closed with sealed member, on the cam chain driving sprocket wheel that is flush-mounted on the bent axle, roll up and hang with under the state of cam chain, use the circular sealed member of the external diameter also bigger that above-mentioned through hole is sealed up than its maximum outside diameter.

During maintenance, under the situation that cam chain is unloaded from the cam chain driving sprocket wheel, the circular sealed member of sealing crankcase partition wall through hole is removed, owing to be formed with opening than the maximum outer light also big through hole under the state that hangs with cam chain on the cam chain driving sprocket wheel, therefore, can utilize this through hole at an easy rate cam chain to be taken off from the cam chain driving sprocket wheel, thereby can carry out simple dismounting operation, improve maintainability with part count seldom.

In the described quartastroke engine crankcase structure of claim 1, above-mentioned circular sealed member is mounted to when sealing up above-mentioned through hole, the outer periphery of this circular sealed member, be positioned at the position of the cam disk slip boss part that is provided with on half belt pulley of movable side near belt type adjustable speed drive, sealed member and belt drives wheel do not interfere, thereby can keep high maintainability.

In claim 1 or the described quartastroke engine crankcase structure of claim 2, be formed with step on the outer periphery of the one side side, belt type adjustable speed drive chamber of above-mentioned circular sealed member, make the sealed member that is pressed in the through hole utilize this step to dismantle at an easy rate, thereby further make maintenance operation become easy.

Fig. 1 is the scooter type motor cycle unitary side view of one embodiment of the invention.

Fig. 2 is the sectional view of cutting open along II-II line among Fig. 1 of this scooter type motor cycle internal-combustion engine.

Fig. 3 is the sectional view of cutting open along III-III line among Fig. 2.

Fig. 4 is the sectional view of cutting open along IV-IV line among Fig. 3.

Fig. 5 is the sectional view of the crankcase structure major component of another embodiment of the present invention.

Below one embodiment of the present of invention are described with reference to Fig. 1-Fig. 4.

Fig. 1 is the side view that has the scooter 1 of component oscillating internal-combustion engine of the present invention.

Vehicular body front 2 couples together by low pedal 4 with rear vehicle 3, the vehicle frame that forms the car body bone roughly by under manage 6 and be responsible for 7 and constitute.

Promptly, managing 6 steering heads 5 from Vehicular body front 2 down extends downwards, this time pipe 6 is at the lower end horizontal curvature, the lower direction rear portion of base plate 4 is extended, be connected with pairing left and right in its back-end and be responsible for 7, be responsible for 7 and rise to certain altitude from this connection part tilted rearward, horizontal curvature rearward extends again.

This person in charge 7 is supporting fuel tank and warehousing case etc., and its top is provided with seat 8.

On the other hand, in the Vehicular body front 2, be provided with up by axle and be supported on handle 11 on the steering head 5, below extend front fork 12, supporting front-wheel 13 in the front fork lower end by axle.

Be responsible for that the lower end of 7 rising parts is outstanding to be provided with carriage 15, on this carriage 15, can connect with freely swinging and be supported with wobble component 17 by connected element 16.

In wobble component 17, its front portion at cylinder body 32 roughly near being equipped with single cylinder quartastroke engine 30 under the horizontal state and with big forward lean, the end of the suspension of forwards giving prominence to from the part lower end suitable with the crankcase of this internal-combustion engine 30 assemblies swing case 31 18 is connected on the above-mentioned connected element 16 by pivot 19.

Be formed with belt type adjustable speed drive 35 to the rear from this internal-combustion engine 30, on the set reducing gear 38 in its rear portion, supporting trailing wheel 21 by axle.

Between the upper end of this reducing gear 38 and the above-mentioned person in charge's 7 upper bend part, rear shock absorber 22 is installed.

Be provided with Carburetor 24 that is connected with suction tude 23 that cylinder cap 33 tops from internal-combustion engine 30 extend out and the air-strainer 25 that is connected with this Carburetor 24 on the top of wobble component 17.

On the outstanding suspension 18 that is provided with in the bottom of opposite side assembly swing case 31, supporting master bracket 26 by axle, at the root of fixing actuating arm 28 from the outstanding starting shafts 27 of the transmission-case cover 36 of belt type adjustable speed drive 35, be provided with starting pedal 29 at the front end of this actuating arm 28.

Vehicular body front 2 is covered from fore-and-aft direction by protecgulum 9a and bonnet 9b, and is covered from left and right sides side by front end lower cover 9c.The middle body of handle 11 is covered by handle cover 9d.

Base plate 4 is covered by side cover 9e, and in addition, rear vehicle 3 is covered from side, the left and right sides by car body lid 10a and afterbody lid 10b.

Fig. 2 is the sectional view that wobble component 17 is blocked expansion along the II-II line among Fig. 1.

Assembly is swung case 31 and is constituted owing to having by left module case 31L that divides right and left and right module case 31R zoarium, therefore, right module case 31R constitutes half of crankcase portion, and left module case 31L is made of the front crankshaft case 31a of portion, the central area transmission case 31b of portion and the rear portion deceleration crate part 31c that size is big on the above-mentioned fore-and-aft direction.

The left side open surface of this left side module case 31L is covered by transmission-case cover 36, and inside contains belt type adjustable speed drive structure 35, and the right side open surface of rear reduction gear case 31c is covered by deceleration cabinet 37, and inside contains reducing gear 38.

In the so-called crankcase of 31a of crankcase portion and right module case 31R, can bent axle 40 be supported on the left and right sides main bearing 41,41 with rotating freely, right extension in the extension that the left and right horizontal direction is extended is provided with DC generator 60, and left extension is provided with cam chain driving sprocket wheel 55 and takes turns 76 with the belt drives of belt type adjustable speed drive 35.

Internal-combustion engine 30 usefulness connecting rods 43 are connected pistons reciprocating 42 in the cylinder liner 44 of cylinder body 32 with the crankpin 40a of bent axle 40.

This quartastroke engine 30 has adopted OHC type valve system, be provided with valve driving mechanism 50 in the valve mechanism cover 34, set up the cam chain 51 of transferring power in valve driving mechanism 50 between camshaft 53 and the bent axle 40, like this, cam chain chamber 52 is communicated with setting with the 31a of crankcase portion, cylinder body 32, cylinder cap 33.

That is, the left end setting-in of the camshaft 53 that is oriented to the left and right horizontal direction by movable sprocket 54 and be flush-mounted between the above-mentioned driving sprocket wheel 55 on the bent axle 40 and set up the cam chain 51 that connects 52 inside, cam chain chamber.

Embedding on cylinder head 33 has from the cam chain chamber 52 opposite sides (right side) towards the spark plug 45 of firing chamber.

Valve driving mechanism 50 in the valve mechanism cover 34 shown in Figure 3 is owing to be near big the leaning forward under the level at cylinder, therefore, the upper-lower position of camshaft 53 disposes suction valve 56 and outlet valve 57, can support Rocker

arm

59,59 by axle respectively on the

pitman arm shaft

58,58 up and down with freely swinging, rotation by camshaft 53 cams; Rocker

arm

59,59 swings, the suction valve 56 under the definition status of being scheduled to and the on-off action of outlet valve 57.

The DC generator 60 that is provided with on the right module case 31R right flank, by the AC motor back-up ring 61 from the end of the outstanding bent axle 30 that is provided with of the right module case 31R cylindrical part 31d of central authorities, fixing bowl-shape external rotor 62, the stator 64 of being reeled and being formed by fixed coil 65 is being fixed in magnet 63 inboards that along the circumferential direction are provided with of side face on central cylindrical part 31d within it.

Forced air cooling fan 66 is installed on the right flank of external rotor 62, and its side is covered by fan guard 67, and fan shroud 68 is provided with to cover the cylinder body 32 and cylinder cap 33 mode on every side that are connected with this fan guard 67.

On the other hand, in the 31a of crankcase portion of assembly swing case 31, just in time separate crankcase chamber by main bearing 41, form above-mentioned cam chain chamber 52, the left side wall of this cam chain chamber 52 is partition walls 71 that the belt type adjustable speed drive chamber 70 of its left and cam chain chamber 52 are separated, be formed with the flat cylindric circular through hole 71a of major diameter that bent axle 40 connects on this partition wall 71, be pressed into circular sealed member 72 in this through hole 71a, bent axle 40 passes the hollow portion of this driving sprocket wheel 55 and cam chain 51.

Circular sealed member 72 is connected by outer side wall 73c with interior ring 73b and the space of the section that constitutes to be the inside of " コ " font form ring-type at the outer shroud 73a of rubber components 73, form the structure be embedded with sheet metal 74 in outer shroud 73a and outer side wall 73c, chimeric on the periphery of interior ring 73b have a pressure ring 74b.

On the bent axle 40 between sealing parts 72 and the main bearing 41, be embedded with above-mentioned driving sprocket wheel 55, volume hangs with cam chain 51 on this driving sprocket wheel 55, in this state, the internal diameter of the external diameter of the outer shroud 73a of circular sealed member 72 and through hole 71a is compared with the maximum outside diameter of cam chain 51 with this driving sprocket wheel 55 and is all wanted big.

Therefore, if circular sealed member 72 is taken out,, cam chain 51 is hung and can both be carried out at an easy rate from driving sprocket wheel 55 dismountings and volume by this opening owing to have large diameter through hole 71a from through hole 71a.

Carry out watertight by 72 pairs of belt type adjustable speed drive chambers of sealing parts 70 and cam chain chamber 52 and separate, thereby prevented that lubricant oil from bleeding in the belt type adjustable speed drive chamber 70.

The bent axle 40 that connects sealed member 72 and extend out can be provided with belt drives wheel 76 therewith rotatably.

Belt drives wheel 76 is made of half belt pulley of fixed side 77 and movable half belt pulley of side 78, fixed side half belt pulley 77 is fixed on the left part of bent axle 40 by back-up ring 79, movable side half belt pulley 78 on its right side is entrenched on the bent axle 40 by spline, this movable side half belt pulley 78 is with bent axle 40 rotations, and can be close with half belt pulley of fixed side 77 and leave by the slip on the axial direction, volume is hung clamping and vee-belt 75 between two

half belt pulley

77,78.

Fixed position on the right side of movable half belt pulley of side 78 near above-mentioned circular sealed member 72 is provided with cam disk 80, and the slider 80a that is arranged on cam disk 80 outer Mondays of end forms with the cam disk slip boss part 78a of the movably outer circumference end axial direction formation of half belt pulley of side 78 and can cooperate with being free to slide.

The side of cam disk 80 1 sides of movable half belt pulley of side 78 forms taper towards cam disk 80 1 sides, and the inboard of this conical surface contains the driven roller 81 that is clipped in the cam disk 80.

Like this, when the rotational speed of bent axle 40 increases, the driven roller that rotates between protruding dish 80 at movable half belt pulley of side 78 81 moves to the direction away from the center of circle by centrifugal force, movable half belt pulley of side 78 moves and near half belt pulley of fixed side 77 to left under the pushing of this driven roller 81, be clipped in vee-belt 75 between two

half belt pulley

77,78 to moving, make the radius of coiling become big away from center of circle direction.

The belt driven wheel 86 of taking turns 76 corresponding rears with this belt drives is to be made of a pair of

half belt pulley

87,88, it is fixed half belt pulley of a side 87 and is inlaid on the inner sliding sleeve 89 that the speed reducer input shaft 92 with respect to reducing gear 38 can support with rotating freely, and movable 88 of half belt pulleys of side are flush-mounted on the outer sliding sleeve 90 on the left side inner sliding sleeve 89 that is supported on half belt pulley of fixed side 87 with in axial direction being free to slide.

Above-mentioned vee-belt 75 in a pair of half belt pulley, 87,88 clampings.

Speed reducer input shaft 92 is provided with centrifugal clutch 91 with the left side of inner sliding sleeve 89, in case input shaft 92 rotational speeies increase, centrifugal clutch 91 is engaged, be delivered to power on the inner sliding sleeve 89, will be delivered to the input shaft 92 of speed reducer by vee-belt 75.

The power that reducing gear 38 will be delivered to speed reducer input shaft 92 by jack shaft 93 again by with the transmission of slowing down of the gear meshing of output shaft 94, output shaft 94 is axletrees of trailing wheel 21, makes trailing wheel 21 rotations.

On the hub portion of trailing wheel 21, be provided with drum-type brake pad 95, be embedded with the drum brakes arm 97 that is connecting brake cable on the drum brakes axle 96, the tractive brake cable, drum brakes arm 97 will be swung, and makes 96 rotations of drum brakes axle, thereby drives drum-type brake pad 95.

Cover the transmission-case cover 36 of belt type adjustable speed drive chamber 70 from the left side, cover the centrifugal clutch 91 at rear from the belt drives wheel 76 in the place ahead always, more forward position can connect with rotating freely and support above-mentioned starting shaft 27 at the middle part, the inner end of this starting shaft 27 is embedded with and drives spiral gear 100, applies elastic force by return spring 101.

Like this, in transmission-case cover 36 anterior the insides, rotatably and along axial direction be slidably supported the sliding axle 102 coaxial with bent axle 40, on this sliding axle 102, be formed with passive spiral gear 103, this gear 103 is meshed with above-mentioned driving spiral gear 100, simultaneously, fixing ratchet 104 integral body of its right-hand member are by friction spring 105 pressuring direction left.

On the other hand, be formed with the ratchet 79a relative with ratchet 105 on the back-up ring 79 of bent axle 40 1 sides, both can engage, separate by the slip of sliding axle 102.

Like this, step on starting pedal 29, by actuating arm 28 starting shaft 27 opposing return springs 101 are rotated, the driving spiral gear 100 that is one with starting shaft 27 just can rotate, and the passive spiral gear 103 that is engaged with will rotate with sliding axle 102, and to anti-wear spring 105 and to right-hand slip, like this, ratchet 105 will be meshed with the ratchet 79a of back-up ring 79, makes bent axle 40 force rotation, thereby can cranking internal combustion engine 30.

On the other hand, this internal-combustion engine disposes actuating motor 110 above the 31a of crankcase portion of left module case 31L, actuating motor 110 shown in Fig. 4 is extruded with small gear 113 to left, be trapped among outer stator magnet 111 internal rotor coil 112 on every side and be wrapped on this small gear 113, be formed with gear 113a in the end of small gear 113.

Like this, the gear mechanism 115 that flies into that is clamped between 31a of crankcase portion and the transmission-case cover 36 is arranged between actuating motor 110 and the belt drives wheel 76, its axle points to substantially horizontal, the small gear 113a that is meshing actuating motor 110 on the gear 116 is imported on this right side that flies into gear mechanism 115, on the other hand, the left side fly into gear 117 when left flies out, be meshed with starting gear 77a on the outer periphery that are formed at half belt pulley of fixed side 77.

The result, when driving actuating motor 110, the rotation of small gear 113 is passed on the input gear 116 that flies into gear mechanism 115, flying into gear 117 flies out to left, be meshed with the starting gear 77a of half belt pulley of fixed side 77, make fixed side half belt pulley 77 with bent axle 40 rotations, thereby internal-combustion engine 30 can be got up.

Moreover, if actuating motor 110 stops, flying into gear 117 and be pulled, so removed engagement with starting gear 77a.

Form half belt pulley of fixed side 77 that acceptance flies into the starting gear 77a of gear 117 engagements, with the side (left surface) of the side of its clamping V shape belt 75 and an opposite side by the rubber sintering being attached with the cooling fan 118 of rubber system, the rotation by cooling fan 118 makes 35 coolings of belt type adjustable speed drive structure.

With reference to Fig. 1 and Fig. 2, outstanding being formed with is positioned at its anterior tubular air inlet duct 36a on transmission-case cover 36, be formed with the tubular exhaust manifolds 36b of fore-and-aft tilt along the sidewall of fore-and-aft direction substantial middle position, above-mentioned suction tude is led the rear end that 36a is connecting snake abdominal cavity 14, forwards extend in this snake abdominal cavity 14, its front end be connected from managing the outstanding outlet pipe 6b that forms of 6 crooked positions down.

Manage near the outstanding suction pipe 6a that is formed with in eminence positions 6 the steering head 5 down, suction pipe 6a and outlet pipe 6b are connected by managing 6 inside down.

Therefore, in belt type adjustable speed drive chamber 70, rotation by bent axle 40 makes cooling fan 118 rotate, suck air from managing 6 suction pipe 6a down, by under manage 6 and enter into snake abdominal cavity 14 from outlet pipe 6b, be drawn in the belt type adjustable speed drive chamber 70 from air inlet duct 36a by snake abdominal cavity 14, belt type adjustable speed drive 35 is cooled off, 36b is discharged to the outside from exhaust manifolds.

This quartastroke engine 30 has above-mentioned structure, above-mentioned belt type adjustable speed drive chamber 70 is carried out watertight by large diameter circular sealed member 72 and is separated, thereby prevented the leakage of lubricant oil, when maintenance if sealing parts 72 are taken off, because opening is the very big through hole 71a of diameter, therefore can very easily cam chain 51 be unloaded from driving sprocket wheel 55, in addition, also easily it is hung up, thereby just not needing specially assembly to be swung case 31 is divided into left and right sides two-part, and does not also need special cover etc., therefore, part count reduces, and is simple in structure, makes maintenance operation simple.

Circular sealed member 72 has big diameter, and the cam disk slip boss part 78a and the outer periphery that are free to slide the slider 80a of chimeric contiguous cam disk 80 peripheries in ground have approaching significantly, thereby sealed member 72 can not take turns 76 with belt drives and interfere, thereby can keep high maintainability.

A variation to sealed member describes with reference to Fig. 5 below.

Except that this sealed member 120, the structure of internal-combustion engine is same as the previously described embodiments, and is represented by identical label.

The 31a of crankcase portion that sealed member 120 is pressed into left module case 31L goes up among the flat cylindrical through hole 71a of the partition wall 71 that forms, in by the outer shroud 121a of the rubber components 121 that constitutes with roughly the same outer shroud 121a, interior ring 121b of above-mentioned sealed member 72 and outer side wall 121c and outer side wall 121c, be embedded with steel plate 122a, chimeric pressure ring 122b on the periphery of interior ring 121b, the curved part from outer side wall 121c to outer shroud 121a forms step 123.

When sealing parts 120 are pressed into through hole 71a, make outer side wall 121c be in the extrusion position more outer by step 123 than the opening of through hole 71a, the discoideus Drop-proof plate 124 of hollow is from the end face and the step 123 of the flat cylindrical part of left pushing through hole 71a, and this Drop-proof plate 124 is fixed on the screw lip part 125 of the 31a of crankcase portion by screw 126.

Drop-proof plate 124 by the step 122a of sealed member 120, is entrenched in its hollow circular open on the periphery of outer side wall 121c of extrusion position of reduced, pushes down step 123, thereby prevents that sealed member 120 from coming off.

Therefore, if the spiral of screw 126 is turned on, and Drop-proof plate 124 is taken down, owing to the outer side wall 121c of sealed member 120 than through hole 71a more outstanding expose, therefore utilize this outer side wall 121c that exposes just easily sealed member 120 to be taken off, thereby can further make upkeep operation become easy.

Under the situation that the present invention need unload cam chain from the cam chain driving sprocket wheel when safeguarding, the circular sealed member that seals the through hole of crankcase partition wall is taken down, owing to be formed with than the also big through hole of maximum outside diameter under the state that hangs at chain roll on the cam chain driving sprocket wheel, utilize this through hole just can at an easy rate cam chain be taken off from the cam chain driving sprocket wheel, thereby can carry out simple dismounting operation with few part count, improve its maintainability.

In case install circular sealed member and seal through hole, this circular sealed member just has makes its outer periphery be in the such crankcase structure in position of cam disk slip boss part set on half belt pulley of movable side near belt type adjustable speed drive, therefore, sealed member and belt drives wheel do not interfere, thereby can keep high maintainability.

Be formed with step on the outer periphery of the one side side, belt type adjustable speed drive chamber of circular sealed member, thereby the sealed member that utilizes this step will be pressed at an easy rate in the through hole takes out, and can further make upkeep operation become easy.

Claims

1, a kind of quartastroke engine crankcase structure, bent axle run through the crankcase partition wall that cam chain chamber and belt type adjustable speed drive chamber are separated, and this through hole closes with sealed member, it is characterized in that:

On the cam chain driving sprocket wheel that is flush-mounted on the bent axle, roll up and hang with under the state of cam chain, use the circular sealed member of the external diameter also bigger that above-mentioned through hole is sealed up than its maximum outside diameter.

2, quartastroke engine crankcase structure as claimed in claim 1, it is characterized in that: when above-mentioned circular sealed member sealed up above-mentioned through hole, the outer periphery of this circular sealed member were positioned at the position of the cam disk slip boss part that is provided with on half belt pulley of movable side near belt type adjustable speed drive.

3, quartastroke engine crankcase structure as claimed in claim 1 or 2 is characterized in that: be formed with step on the outer periphery of the one side side, belt type adjustable speed drive chamber of above-mentioned annular seal parts.