CN101634270B - Vehicle engine unit, and straddle-type vehicle - Google Patents

Abstract

The invention provides a vehicle engine unit capable of improving fuel combustion efficiency by promoting fuel atomization and preventing the fuel from being blown back to a secondary air inlet channel by a simple structure with low cost, the vehicle engine unit has excellent response to a throttle operation, and the invention also provides a straddle-type vehicle having the engine unit. An intake air pipe 62 connected to a cylinder head 22 defines a part of a main air intake passage B3. Two throttle valves 69A,69B are disposed in a tubular member 64 spaced apart from each other in an intake air flow direction El.An auxiliary air intake passage C1 communicating with a portion of the main air intake passage B3 between the two throttle valves 69A,69B to guide intake air into a space adjacent to the injector 47 at least during idling is formed. The center axis F1 of the auxiliary air intake passage C1 crosses a plane G2. The plane G2 contains a straight line segment G1 that extends between the opposite ends F2, F3 of the center axis F1.

Description

Mobile engine unit and Straddle-type vehicle with this engine unit

Technical field

The present invention relates to mobile engine unit and Straddle-type vehicle.

Background technique

As patent documentation 1 was put down in writing, some engine unit that vehicle etc. had had through to blowing the structure that air stream promotes fuel atomization from the sparger injected fuel.

In patent documentation 1, comprising: cylinder head, the suction tude that is connected with cylinder head, be inserted into the Fuelinjection nozzle main body in the suction tude and connect the upper reaches of air inlet shutter and near the secondary path the Fuelinjection nozzle via adapter.Thus, when low load operation etc., flow in the secondary path from the air inlet of primary path.The air inlet of having passed through secondary path is blown to from the sparger injected fuel, promotes fuel atomizing.Thus, improved the combustion efficiency of fuel.

And, in patent documentation 1, be provided with zone and the communication path in zone midway of secondary path near the firing chamber that is communicated with in the primary path.And, control the switching of communication path through the control valve and the control gear of this control valve of control.When high capacity, control valve is opened according to the instruction of control gear, thus near the zone the firing chamber in the primary path and the regional connectivity midway of secondary path.Thus, the pressure in the secondary path become with the firing chamber near the pressure of primary path identical.As a result, owing to can make and do not produce pressure difference, therefore can suppress fuel and blown and get back in the secondary path at the sparger periphery.

Patent documentation 1: the Japanese documentation spy opens flat 5-10224 communique.

Summary of the invention

But, according to the structure of patent documentation 2, owing to need the control gear of control valve and this control valve of control, so device can become complicated, cost up.

Therefore, the object of the present invention is to provide a kind of through promoting fuel atomizing to improve the combustion efficiency of fuel, having suppressed fuel through simple and low-cost configuration and blown and get back in the secondary path and to the good mobile engine unit of the response of throttle operation with have the Straddle-type vehicle of this engine unit.

In order to achieve the above object, mobile engine of the present invention unit comprises: engine main body has cylinder head, the part of the part of this cylinder head formation firing chamber and the main inlet air pathway that is connected with said firing chamber; Suction tude forms said main inlet air pathway with said cylinder head connection and with said cylinder head; Throttle body has in said suction tude devices spaced apart on the flow direction of air inlet and two throttle valve disposing and form the part of said suction tude and hold the cylinder of said two throttle valve; And fuel injection system, be installed on the said cylinder head the said main inlet air pathway burner oil in said cylinder head.In addition; Mobile engine of the present invention unit comprises the secondary inlet air pathway organizator that forms secondary inlet air pathway, and this pair inlet air pathway is communicated with said main inlet air pathway between said two throttle valve and when idle running, said air inlet is imported at least near the space the said jet nozzles.The center line of said secondary inlet air pathway with comprise that the face with lower line segment intersects, said line segment links an end and the other end of said center line with the shortest distance.

Vehicle according to the invention is used engine unit, can provide a kind of through promoting fuel atomization to improve the combustion efficiency of fuel, having suppressed fuel through simple and low-cost configuration and blown and get back in the secondary inlet air pathway and to the good engine unit of the response of throttle operation with have the Straddle-type vehicle of this engine unit.

Description of drawings

Fig. 1 is the left surface figure of the automotive bicycle of mode of execution one of the present invention;

Fig. 2 is the sectional view of engine unit, the state when having represented from right flank observation engine unit;

Fig. 3 is the sectional view of the cylinder head periphery of Fig. 2;

Fig. 4 is the sectional view along the IV-IV line intercepting of Fig. 3;

Fig. 5 is the planimetric map of engine unit;

Fig. 6 is the left surface figure that has amplified the periphery of throttle body;

Fig. 7 is the figure of relation of aperture of aperture and second throttle valve of expression first throttle valve;

Fig. 8 is the schematic left surface figure of the first throttle valve and second throttle valve throttle body when being full-gear;

Fig. 9 is the right hand view of engine unit;

Figure 10 is the performance plot of length with the relation of blowing back of vice inlet air pathway;

Figure 11 is the enlarged view of the right flank of secondary inlet air pathway organizator periphery;

Figure 12 is the enlarged view on the plane of secondary inlet air pathway organizator periphery;

Figure 13 is the back elevation of secondary inlet air pathway organizator periphery;

Figure 14 is the right hand view of the automotive bicycle of mode of execution two;

Figure 15 is a right hand view of representing the part of engine unit through the cross section;

Figure 16 is the sectional view along the XVI-XVI line intercepting of Figure 15;

Figure 17 is the planimetric map of engine unit;

Figure 18 is the right hand view of the major component of engine unit;

Figure 19 is the planimetric map of the engine unit of secondary inlet air pathway organizator periphery;

Figure 20 is the front elevation of the engine unit of secondary inlet air pathway periphery;

Figure 21 is the front elevation of the major component of automotive bicycle when being supported by side support;

Figure 22 is the sectional view of the major component of another embodiment of the present invention;

Figure 23 is the left surface figure of the major component of another embodiment of the present invention, has represented a part through the cross section;

Figure 24 is the right hand view of the major component of another embodiment of the present invention, has represented a part through the cross section;

Figure 25 is the planimetric map of the major component of another embodiment of the present invention, has represented a part through the cross section;

Figure 26 is the planimetric map of the major component of another embodiment of the present invention, has represented a part through the cross section.

Embodiment

(accomplishing process of the present invention and main points of the present invention)

Inventor of the present invention has studied and has suppressed fuel through simple structure and blown the method for getting back in the secondary inlet air pathway.

At first, inventor of the present invention has carried out being used to study the experiment of the reason of blowing back.The application's claimant is that understood can the said fuel of generation blowing back to secondary inlet air pathway motor is transformed into during intake stroke of short duration from exhaust stroke in accomplishing the result of experiment of carrying out before the present invention.Think that such phenomenon is following the generation.

In this part, before the detailed structure of explanation mode of execution of the present invention, the main points relevant with the present invention are described at first.

With reference to Fig. 2, if known exhaust is discharged from relief opening 31 times without number, then consequent pressure oscillation meeting becomes pressure wave, and in outlet pipe 34, transmits back and forth.On the other hand, the initial stage of the final period of exhaust stroke and intake stroke repeated in the of short duration time.Therefore, in this recycling time, outlet valve 36 and suction valve 37 all are in out the state of valve.If the high-pressure section of pressure wave arrives relief opening 31 parts when these both sides are out the valve state, then this high-voltage section branch hinders exhaust smoothly, and can impact secondary inlet air pathway C1 side.That is, the entering smoothly of mixed gas is hindered, and the result shows as the part of fuel and blown the phenomenon of getting back among the secondary inlet air pathway C1.Like this in the high speed operation zone of the phenomenon of blowing back that kind shown in figure 10 of secondary inlet air pathway C1, be significant at engine main body 14.

In Figure 10, mean mass flux is meant the average quality (g/sec) through the time per unit of the auxiliary air of the downstream C3 of secondary inlet air pathway C1 (assist air).In Figure 10, (+) means flowing towards the postive direction of jet nozzles 47b.In addition, (-) mean reciprocally flow, be that fuel is blown and gets back among the secondary inlet air pathway C1.The length of transverse axis vice inlet air pathway C1.Thus, if the length of having distinguished secondary inlet air pathway C1 more than or equal to predetermined length, then regardless of the rotational speed of engine main body 14, all can be avoided fuel to be blown and get back among the secondary inlet air pathway C1.In reality, consider the deviation of product, think that near length that frame line by the solid line of Figure 10 surrounds is only as the length of secondary inlet air pathway C1.Relative therewith, secondary in the past inlet air pathway connects the upstream extremity and the downstream of its flow direction with the shortest distance.(in fact, consider the stringing operation and that it is had is a spot of lax.) result, the length of secondary inlet air pathway is by near the length the frame line encirclement of dotted line in Figure 10.

With reference to Fig. 2,, be to make the length of secondary inlet air pathway C1 more than or equal to predetermined length for the basic countermeasure that blows back to secondary inlet air pathway C1 based on above-mentioned opinion.For example, also can consider through making throttle body 68 whether effective from the method for the farther length of guaranteeing secondary inlet air pathway C1 of cylinder head 22.

But throttle body 68 is relevant with combustion position with distance between the sparger 47.Therefore, if unconditionally change the distance between throttle body 68 and the sparger 47, then combustion position may worsen.And, such motor is being installed under the situation on the automotive bicycle, it is big that vehicle can become.Therefore, inventor of the present invention thinks that such countermeasure lacks fasibility.

In addition, also can consider and the link position at the two ends of secondary inlet air pathway C1 and identical in the past, the secondary inlet air pathway C1 that extends only.But inventor of the present invention thinks if without a moment's thought elongated so secondary inlet air pathway C1 is carried out stringing, and then stringing zone expansion unexpectedly can become problem with the interference of peripheral device.

Inventor of the present invention expected that kind shown in figure 12 according to the center line F1 that makes secondary inlet air pathway C1 with comprise that linking the mode that the face G2 of line segment G1 of an end F2 and the other end F3 of center line F1 intersects with beeline disposes secondary inlet air pathway C1.Through such structure, because secondary inlet air pathway C1 is formed the extension of wriggling, secondary inlet air pathway C1 fully therefore can extend.Thus, can guarantee that near the fluid of space in secondary inlet air pathway C1 the jet nozzles that enough downstream C3 from secondary inlet air pathway C1 are communicated with passes through resistance.

As a result, even produced blowing back of fuel near the space jet nozzles, also can make the fuel that is blown back be difficult to invade among the secondary inlet air pathway C1.In addition, extend,, also can near main inlet air pathway B3, be configured compactly even therefore guaranteed the length of secondary inlet air pathway C1 fully because secondary inlet air pathway C1 is wriggled.In addition, the so simple structure of the sinuous extension of secondary inlet air pathway C1 is got final product, therefore can simply also realize at low cost being used for preventing that fuel from being blown the structure of getting back to secondary inlet air pathway C1 owing to adopting.In addition, not the length that makes two throttle valve 69A, 69B prolong secondary inlet air pathway C1, but extend the path length of guaranteeing necessity through secondary inlet air pathway C1 is wriggled away from cylinder head 22.Therefore, need not prolong distance from two throttle valve 69A, 69B to the firing chamber.Thus, can realize good response to throttle operation.

(mode of execution one)

Below, with reference to accompanying drawing mode of execution one of the present invention is described.In following explanation, front and back, up and down, about all directions be that to be in the viewpoint that is equivalent to the benchmark posture of straightaway state on the horizontal plane and driver this driver during towards the place ahead with automotive bicycle 1 be benchmark.

In addition, in each figure, represent the place ahead of automotive bicycle through arrow F.Likewise, in each figure, represent the rear of automotive bicycle through arrow B; The top of representing automotive bicycle through arrow U; Represent the below of automotive bicycle, to represent the right-hand of automotive bicycle through arrow D through arrow R through the left that arrow L representes automotive bicycle.

Fig. 1 is the left surface figure of the automotive bicycle 1 of mode of execution one of the present invention.In Fig. 1, blocked the part of automotive bicycle 1 and represented.In addition, among each figure below Fig. 1, imaginary line is double dot dash line.In addition, in each figure, represent hidden line by a dotted line.

In this mode of execution, automotive bicycle 1 is scooter (scooter).In this mode of execution, as an example of automotive bicycle of the present invention scooter is described, but is not limited thereto.The present invention also can be applied to scooter so-called motorcycle (motorcycle), autocycle (moped), go-anywhere vehicle (off road), ATV (ATV, All Terrain Vehicle) in addition and wait other Straddle-type vehicle.

The integral body of in Fig. 1, having represented the automotive bicycle of this mode of execution.Automotive bicycle 1 has handle 2 in its front portion.Handle 2 can turn to front-wheel 6 with front fork 5 via the steering shaft 4 that runs through head pipe 3.On head pipe 3, be combined with vehicle frame 8.

The top of head pipe 3 is covered by cowling 9.The integral body of vehicle frame 8 is covered by body cover 10.Dispose vehicle seat 11 on the top of body cover 10.

Vehicle frame 8 comprises main car frame 12.Engine unit 13 is installed on main car frame 12.Engine unit 13 comprises engine main body 14, is used for the power transfering part 16 with transmission of power to trailing wheel 5 sides of engine main body 14.This engine unit 13 can be supported by vehicle frame 8 around pivot 17 rotatably.

In the binding of the rear portion of engine unit 13 trailing wheel 5 is arranged.Be connected with the lower end of rear shock absorber 18 on the top of power transfering part 16.In addition, the upper end of rear shock absorber 18 is connected with vehicle frame 8.Thus, engine unit 13 can be with trailing wheel 16 around pivot 17 swings.

Like this, formed swing bodies formula motor.In addition, stipulated to link the vehicle center axis A1 of central axis of central axis and the trailing wheel 15 of front-wheel 6.Vehicle center axis A1 is configured in the central authorities of automotive bicycle 1 on left and right vehicle wheel direction Y1 (direction vertical with the paper of Fig. 1).

Fig. 2 is the sectional view of engine unit 13, has represented to observe from right flank the state of engine unit 13.Engine main body 14 has the sparger 47 of the injection apparatus that acts as a fuel.Engine main body 14 is four-cycle, single-cylinder engines.

Engine main body 14 is in approximately horizontally configuration under the state in the place ahead of cylinder-bore axis A2.

Engine main body 14 comprises crankcase 20, cylinder block (cylinder block) 21, cylinder head 22.In crankcase 20, accommodate bent axle 23.Cylinder block 21, cylinder head 22 successively lamination on the antetheca of crankcase 20.These crankcases 20, cylinder block 21 and cylinder head 22 use bolts etc. link together each other.Front end in cylinder head 22 is equipped with valve mechanism cover 24.In addition, the place ahead of the valve mechanism cover 24 on vehicle fore-and-aft direction X1 is equipped with the air-strainer 25 that is used to purify the air that air inlet uses.Air-strainer 25 constitutes the part of engine unit 13.

In the cylinder thorax 26 of cylinder block 21, can accommodate piston 27 with being free to slide.Piston 27 links via connecting rod 28 and bent axle 23.In cylinder head 22, be formed with burning recess 29.Burning recess 29 is configured in the part place that engages with cylinder thorax 26 of cylinder head 22.Space between the burning recess 29 of cylinder head 22, cylinder thorax 26, the piston 27 is firing chamber B4.

On cylinder head 22, be formed with relief opening 31 and suction port 32.One end of relief opening 31 is through being communicated with firing chamber B4 to burning recess 29 openings.One end of suction port 32 is through being communicated with firing chamber B4 to burning recess 29 openings.Relief opening 31 forms exhaust passageway B5 in cylinder head 22.Exhaust passageway B5 extends downwards in cylinder head 22.The internal communication of the other end of exhaust passageway B5 and outlet pipe 34 (with reference to Fig. 7).On the other hand, the main inlet air pathway B32 in the suction port 32 formation cylinder head 22.

One end of relief opening 31 opens and closes through the valve head 39A that is arranged on the outlet valve 36 on the cylinder head 22.In addition, an end of suction port 32 opens and closes through the valve head 39B that is arranged on the suction valve 37 on the cylinder head 22 equally.

Outlet valve 36 has valve spring 38.The valve head 39A of 38 pairs of outlet valves 36 of this valve spring applies the spring force on the direction of an end of closing relief opening 31.Suction valve 37 has valve spring 38.The valve head 39B of 38 pairs of suction valves 37 of this valve spring applies the spring force on the direction of an end of closing relief opening 31.In cylinder head 22, between the part that is provided with each valve spring 38, dispose camshaft 40.Camshaft 40 has the cam 41 that air inlet, exhaust use and is rotatably supported by cylinder head 22.

Exhaust is configured between the shaft end of camshaft 40 and outlet valve 36 with vertical posture with lock arm 42.Exhaust is supported with locking arm axle 42A by exhaust with lock arm 42 swingably.

On the other hand, air inlet is configured between the shaft end of camshaft 40 and suction valve 37 with vertical posture with lock arm 43.Air inlet is supported with locking arm axle 43A by air inlet with lock arm 43 swingably.One end of each lock arm 42,43 that air inlet is used, exhaust is used respectively can be with predetermined timing contact cam 41.Thus, distolateral at another of each lock arm 42,43, the front end of each valve shaft of suction valve 37 and outlet valve 36 is pressed respectively.Thus, outlet valve 36 and suction valve 37 carry out the opening operation of gas port 31,32 respectively with predetermined timing in opposing valve spring 38,38.

Near the suction port 32 on the right flank top of cylinder head 22, dispose sparger 47.

Fig. 3 is the sectional view of cylinder head 22 peripheries of Fig. 2.As shown in Figure 3, the part of sparger 47 is contained in first boss (boss) 45 that is formed on the cylinder head 22, and is installed on this cylinder head 22.

First boss 45 forms with cylinder head 22.The inner space of first boss 45 is communicated with the main inlet air pathway B32 of suction port 32.

The sparger 47 of the injection apparatus that acts as a fuel is installed via plastic fixture 46 on first boss 45.Thus, sparger 47 is installed on the cylinder head 22.

Fixture 46 comprises cylindrical part 48 and the lip part 49 that is arranged on the cardinal extremity of cylindrical part 48.The top butt of the lip part 49 and first boss 45.Thus, fixture 46 is positioned with respect to first boss 45.Cylindrical part 48 is contained in first boss 45.Thickly sealed by first sealed member, 52 liquid such as O type rings between the outer circumferential face of the base end part 51 of cylindrical part 48 and the inner peripheral surface of first boss 45.Between the inner peripheral surface of the outer circumferential face of the intermediate portion 53 of cylindrical part 48 and first boss 45, be formed with chamber B1 as annular gap.The tip edge of the tip portion 54 of cylindrical part 48 and the inner peripheral surface of first boss 45 are almost seamlessly chimeric.

The inner space of the tip portion 54 of cylindrical part 48 is used as jet space B2, and this jet space B2 is near the space of sparger 47.Jet space B2 is formed on the cylinder head 22, is communicated with firing chamber B4 via suction valve 37.On the tip portion 54 of cylindrical part 48, be formed with a plurality of through holes 55.

With reference to Fig. 3 with as Fig. 4 along the sectional view of the IV-IV line intercepting of Fig. 3, through hole 55 the tip portion 54 of cylindrical part 48 circumferentially on equally spaced be formed with a plurality of (for example four).Chamber B1 and jet space B2 are communicated with through this through hole 55.

After the downstream C3 of the secondary inlet air pathway C1 that states be communicated with chamber B1.The tip portion 54 of cylindrical part 48 comprises the relative portion 56 relative with this downstream C3.Do not forming through hole 55 in the portion 56 relatively.Thus, passed through secondary inlet air pathway C1 after the auxiliary air stated can be in the circumferential four corner of chamber B1 no bias flows.

With reference to Fig. 3, sparger 47 is used for the fuel of fuel tank (not shown) is ejected in the inlet air pathway.This sparger 47 comprises injector body 47a with elongated shape and the jet nozzles 47b that is configured in the top of injector body 47a.

Injector body 47a runs through the cylindrical part 48 of fixture 46 and is kept by this fixture 46.The length direction of injector body 47a roughly half is contained in first boss 45.Between the inner peripheral surface of the outer circumferential face of injector body 47a and fixture 46 through second sealed members 58 such as O type rings and thickly sealed by liquid.Jet nozzles 47b with in the face of jet space B2 and via the main inlet air pathway B32 in the cylinder head 22 to suction valve 37 ejection fuel towards configuration.

Sparger 47 is as a whole along with more to the rear extension of vehicle and offside in the below.Therefore, flow in the burning recess 29 through suction port 32 by injected fuel.Thus, in burning recess 29, produce eddy flow.

Sparger 47 to the timing of suction port 32 burner oils by not shown ECU (EngineControl Unit, control unit of engine; Be also referred to as Electronic Control Unit, electronic control unit) equal controller control.

Fig. 5 is the planimetric map of engine unit 13.With reference to Fig. 3 and Fig. 5, be provided with engine side flange 59 at the upper surface of cylinder head 22.On the left and right directions Y1 of vehicle, the central axis of engine side flange 59 is near the cylinder-bore axis A2 configuration of engine main body 14.Main inlet air pathway B32 in the cylinder head 22 in cylinder head 22 to above extend.The end of this main inlet air pathway B32 is formed by engine side flange 59.

In planimetric map, vehicle center axis A1 overlaps with cylinder-bore axis A2.

With reference to Fig. 2, air-strainer 25 forms the case shape as a whole and is configured in the place ahead of engine main body 14.Air-strainer 25 can be through air suction inlet 60 to inside picked-up extraneous gas.

In this mode of execution, making the division direction in the air-strainer 25 is above-below direction.But, be not limited thereto.Division direction in the air-strainer 25 also can be vehicle fore-and-aft direction X1, perhaps can also be left and right vehicle wheel direction Y1.Be filtered through filter 61 from the extraneous gas of above-mentioned air suction inlet 60 picked-ups, and by from air inlet with flexible pipe 63 sucking-offs.

Engine side flange 59 is connected via suction tude 62 with air-strainer 25.Suction tude 62 forms the part of main inlet air pathway B3 and is configured in the top of engine main body 14.Suction tude 62 is rearward extended from the front side on the vehicle fore-and-aft direction X1.Suction tude 62 comprises: be connected with air-strainer 25 and the air inlet that is configured to rearward extend with flexible pipe 63; The cylinder cylindraceous 64 that is connected with the rearward end of flexible pipe 63 with air inlet; And be connected and the reclinate connecting tube 65 of rearward end with the rearward end of cylinder 64.

With reference to Fig. 5, air inlet is connected with the part in the place ahead on the right side in the upper surface of the front end of flexible pipe 63 and the housing 66 of air-strainer 25.Air inlet with flexible pipe 63 from the upper surface of housing 66 begin in the central bend of left and right vehicle wheel direction Y1 to above extend.On left and right vehicle wheel direction Y1, overlap part with the position of the central axis of flexible pipe 63 with the position of vehicle center axis A1 from air inlet and begin, air inlet is extended to rear view of vehicle along vehicle center axis A1 with flexible pipe 63.Air inlet is connected with the front end of cylinder 64 with the rearward end of flexible pipe 63.Cylinder 64 is configured in air inlet with between flexible pipe 63 and the connecting tube 65.

Cylinder 64 is roughly extended along vehicle center axis A1 in the planimetric map of vehicle with connecting tube 65.

As shown in Figure 2, when when right flank is observed automotive bicycle 1, cylinder 64 and connecting tube 65 are along with extending and offside in the below to rear view of vehicle more.

Connecting tube 65 is in the midway downwards bending of the front end that is connected from the rearward end with cylinder 64 to the rear extension of vehicle fore-and-aft direction X1.Rearward end side at connecting tube 65 is provided with suction tude side flange 67.Suction tude side flange 67 docks with engine side flange 59 each other, and uses not shown fixing bolt to be fixed.Thus, the main inlet air pathway B31 in main inlet air pathway B32 in the suction port 32 and the suction tude 62 is communicated with, and has formed main inlet air pathway B3 as a whole.

Engine unit 13 is provided with throttle body 68.Throttle body 68 comprises above-mentioned cylinder 64 and two the first and second throttle valve 69A, 69B as throttle valve.

Cylinder 64 is configured in the top of the valve mechanism cover 24 of engine main body 14.

The first and second throttle valve 69A, 69B are respectively applied for the main inlet air pathway B31 that opens and closes in the suction tude 62.The first throttle valve 69A and second throttle valve 69B devices spaced apart and disposing on the flow direction E1 of the air inlet of main inlet air pathway B3.The first throttle valve 69A and the second throttle valve 69B are contained in the cylinder 64.On the flow direction E1 of air inlet, first throttle valve 69A is configured in the position of leaning on downstream than the second throttle valve 69B.That is, between the second throttle valve 69B and cylinder head 22 of first throttle valve 69A in main inlet air pathway B3.The first throttle valve 69A and the second throttle valve 69B form discoideus respectively.

First throttle valve 69A is supported by first running shaft 71 that the central axis with cylinder 64 extends perpendicularly.The second throttle valve 69B is supported by second running shaft 72 that the central axis with cylinder 64 extends perpendicularly.First running shaft 71 and second running shaft 72 extend along left and right vehicle wheel direction Y1 respectively.

Fig. 6 is the left surface figure that has amplified the periphery of throttle body 68.Be the left surface figure of engine unit 13.With reference to Fig. 6, first running shaft 71 and second running shaft 72 are outstanding to the left of cylinder 64 from the left surface of cylinder 64 respectively.

In this mode of execution, be that benchmark describes when being in full-shut position with the first throttle valve 69A and the second throttle valve 69B." the first throttle valve 69A and the second throttle valve 69B full cut-off " is meant the first throttle valve 69A in throttle grip not operated when idle running and the state of the second throttle valve 69B.

First running shaft 71 and second running shaft 72 are rotatably supported by cylinder 64 respectively.Through the rotation of first running shaft 71, first throttle valve 69A rotates around first running shaft 71 and first running shaft 71 integratedly.Likewise, through the rotation of second running shaft 72, the second throttle valve 69B rotates around second running shaft 72 and second running shaft 72 integratedly.

But the mode of rotating with one in the left part of second running shaft 72 links driving pulley 73 is arranged.Carburetor cable 74 is installed on driving pulley 73.One end of carburetor cable 74 and the throttle grip of handle 10 link.The other end of carburetor cable 74 and driving pulley 73 link.Through said structure, driving pulley 73 rotates with driver's throttle operation linkedly.Through the rotation of driving pulley 73,72 rotations of second running shaft, the second throttle valve 69B is opened and closed.

The on-off action of the on-off action of the second throttle valve 69B and first throttle valve 69A is through linkage mechanism 75 and interrelated.That is, the first and second throttle valve 69A, 69B interlock.

Linkage mechanism 75 has so-called lost motion (lost motion) structure, and first throttle valve 69A is later than the beginning of starting work of the second throttle valve 69B and begins to start work.This linkage mechanism 75 is configured in the left of the cylinder 64 of throttle body 68, and comprises first main link component 76, is configured in second main link component 77, slave connecting rod parts 78 and the rotation transmission member 79 in the place ahead of first main link component 76.

Second main link component 77 is the little chip parts that form as one with driving pulley 73, can rotate integratedly with second running shaft 72.Second main link component 77 can carry out via second connection shaft 80 with the relative rotation linking with the rearward end of slave connecting rod parts 78.

Slave connecting rod parts 78 are sheet metal members long on vehicle fore-and-aft direction X1, are associated with second main link component 77 and first main link component 76.

Slave connecting rod parts 78 are configured in the below of first running shaft 71 and second running shaft 72.

The elongated parts that first main link component 76 is to use sheet metal to form.First main link component 76 is extended to the rear lower side.The front end of the underpart of first main link component 76 and slave connecting rod parts 78 can link via first connection shaft 81 with the relative rotation.First connection shaft 81 is axles parallel with first running shaft 71.

The upper end portion of first main link component 76 comprises that the extension to extend away from the mode of the central axis J3 of first running shaft 71 is provided with portion 50.This extension is provided with portion 50 and is provided with pressing component 82.It is outstanding to a circumferential side (being right-hand among Fig. 6) of first running shaft 71 that pressing component 82 is provided with portion 50 from extension.Thus, pressing component 82 and rotation transmission member 79 after the portion that is pressed 83 that states week of first running shaft 71 upwards relatively.

The intermediate portion of first main link component 76 can carry out linking with first running shaft 71 with the relative rotation.Thus, first main link component 76 can be rotated with first running shaft 71 mutually independently.

From being K2 to the distance of the central axis J2 of second connection shaft 80 as the central axis J1 of second running shaft 72 of the oscillation center of second main link component 77.In addition, from being K2 to the distance of the central axis J4 of first connection shaft 81 as the central axis J3 of first running shaft 71 of the oscillation center of first main link component 76.Apart from the relation that exists K2＞K1 between K1, the K2.

Rotation transmission member 79 is the parts that formed by panel beating.But rotation transmission member 79 one link with first running shaft 71 rotatably.On rotation transmission member 79, be formed with can with the portion that is pressed 83 of pressing component 82 butts.The portion 83 that is pressed extends with the mode that the central axis J3 from first running shaft 71 leaves.When the second throttle valve 69B was in full-shut position, pressing component 82 was relative upwards separating predetermined interval J5 the week of first running shaft 71 with the parts 83 that are pressed.

With reference to Fig. 5, between the cylinder 64 of throttle body 68 and first main link component 76, dispose first torsion coil spring 84.Thus, first throttle valve 69A is applied towards the power of closing the valve direction.

In addition, between the cylinder 64 of throttle body 68 and driving pulley 73, dispose second torsion coil spring 85.The power of second torsion coil spring 85 is delivered to second running shaft 72 via driving pulley 73.Thus, the second throttle valve 69B is applied towards the power of closing the valve direction.

Engine unit 13 has secondary inlet air pathway organizator 91.Secondary inlet air pathway organizator 91 forms secondary inlet air pathway C1.The upstream extremity C2 of secondary inlet air pathway C1 is connected with main inlet air pathway B3 between the first and second throttle valve 69A, 69B.In addition, the downstream C3 of secondary inlet air pathway C1 is connected with chamber B1.This pair inlet air pathway C1 is through making auxiliary air and colliding the effect that promotes fuel atomization of bringing into play from sparger 47 injected fuel mutually.The structure of secondary inlet air pathway organizator 91 and secondary inlet air pathway C1 will at length be explained in the back.

Fig. 7 is the figure of relation of aperture of aperture and the second throttle valve 69B of expression first throttle valve 69A.In Fig. 7,, be expressed as zero in the time of will dallying about the aperture of first throttle valve 69A.Likewise, about the aperture of the second throttle valve 69B, be expressed as zero in the time of also will dallying.

In Fig. 7, the figure of solid line representes the first and second throttle valve 69A in this mode of execution, the aperture of 69B.Shown in the figure of this solid line, when the aperture of the second throttle valve 69B is 10 degree when following, the aperture of first throttle valve 69A remains 0 and spends.

On the other hand, in Fig. 7, the figure of dotted line has represented owing to the identical all the time situation of aperture that lost motion mechanism makes first and second throttle valve is not set.Shown in the figure of the figure of these dotted lines and solid line, in this mode of execution, the second throttle valve 69B is later than first throttle valve 69A and starts work.Below, the action of the first and second throttle valve 69A, 69B is described in further detail.

With reference to Fig. 6 and Fig. 7, the aperture of the first throttle valve 69A and the second throttle valve 69B is accompanied by the variation of load (throttle operation amount) and is done as follows control.At first, the first throttle valve 69A in downstream side that is positioned at the flow direction C1 of air inlet remains full close position from non-loaded (idle running) operation area to predetermined partial load run zone.

Specifically, till the partial load run zone, be accompanied by driver's throttle operation and the rotation of the driving pulley 73 that produces is not passed to first running shaft 71, and only be passed to second running shaft 72.

This is that the parts 83 that are pressed owing to pressing component of first main link component 76 82 and rotation transmission member 79 are in the reason of spaced apart interval J5 that makes progress in the week of first running shaft 71.At this moment, first main link component 76 is swung with the swing of second main link component 77 mutually linkedly, but rotation transmission member 79 is not swung.

Therefore, through the rotation of second running shaft 72, only the second throttle valve 69B opens and closes.At this moment, the action of slave connecting rod parts 78 and first main link component 76 and second main link component 77 is moved linkedly.Thus, first main link component 76 is around 71 rotations of first running shaft.But before the pressing component 82 and portion's 83 butts that are pressed of first main link component 76, first running shaft 71 does not rotate with first throttle valve 69A.

Therefore, like Fig. 3 and shown in Figure 6, till the partial load run zone, the air quantity that flow among the jet space B2 is only controlled based on the aperture of the second throttle valve 69B.In this partial load run zone, the auxiliary air that flow among the secondary inlet air pathway C1 is directed among the jet space B2 via the through hole 55 of chamber B1 and fixture 46.The auxiliary air that is supplied among the jet space B2 mixes in jet space B2 with from sparger 47 injected fuel mutually.

At this moment and since sparger 47 be configured in suction valve 37 near, therefore can suppress burner oil attached on the wall around the suction port 32.Thus, can improve engine response to throttle operation.In addition, can promote fuel atomizing, improve the combustion efficiency of fuel.Therefore, can also reduce the unburned fuel that when the cold starting of motor, is easy to generate.

On the other hand, be transformed into the process of high capacity operation area from the partial load zone, first throttle valve 69A opens corresponding to throttle operation.

Thus, be not only the auxiliary air through secondary inlet air pathway C1, the air inlet of the other end through suction port 32 also is directed in the cylinder head 22.

Specifically; With reference to Fig. 7 and Fig. 8; When the partial load zone is transformed into the high capacity operation area; The rotating amount that with idle running the time is first main link component 76 of benchmark surpasses predetermined value, and wherein Fig. 8 is the schematic left surface figure of the first throttle valve 69A and the second throttle valve 69B throttle body 68 when being in full-gear.As a result, the pressing component 82 of first main link component 76 and the portion that is pressed 83 butts of rotation transmission member 79.Thus, the rotation of rotation transmission member 79 and first running shaft 71 and first main link component 76 is rotated linkedly, first throttle valve 69A rotation.Thus, be not only the air inlet through secondary inlet air pathway C1, the air through connecting tube 65 also is directed in the cylinder head 22.

As previously mentioned, in linkage mechanism 75, owing to apart from K2＞apart from K1, therefore in the high capacity operation area, compare with the opening and closing speed of the second throttle valve 69B, the opening and closing speed of first throttle valve 69A is faster.As a result, when having made the second throttle valve 69B standard-sized sheet, first throttle valve 69A also becomes standard-sized sheet.

Fig. 9 is the right hand view of engine unit 13.With reference to Fig. 9, on vehicle fore-and-aft direction X1, the length of secondary inlet air pathway organizator 91 is approximately length half the of suction tude 62.Below, secondary inlet air pathway C1 is carried out detailed explanation.

With reference to Fig. 2, first boss 45 forms with cylinder head 22.On first boss 45, sparger 47 is installed.On first boss 45, formed the 4th boss 95.The 4th boss 95 extends with respect to the axis normal ground of sparger 47.The 3rd boss 94 is installed on the 4th boss 95.

Secondary inlet air pathway organizator 91 comprises: be fixed on second boss 92 on the cylinder 64, be formed on the 4th boss 95 on the cylinder head 22, the flexible pipe 93 that is installed in the 3rd boss 94 on the 4th boss 95 and connects the 3rd boss 94 and second boss 92.In this mode of execution, " secondary inlet air pathway C1 " is meant the space that is formed in second boss 92, flexible pipe 93, the 3rd boss 94 and the 4th boss 95.Passed through should pair inlet air pathway C1 auxiliary air be supplied to jet space B2 as " near the space the jet nozzles ".

Second boss 92 is the metal tubes that form the L word shape.Second boss 92 comprises the upstream extremity formation portion 97 on the top 96 of the cylinder 64 that is fixed on throttle body 68 and extends the extension that is provided with from upstream extremity formation portion 97 portion 98 is set.

Upstream extremity formation portion 97 forms the upstream extremity C2 of secondary inlet air pathway C1.Upstream extremity formation portion 97 is connected with the top 96 of the cylinder 64 of throttle body 68, and extends to the top from this top 96.Thus, upstream extremity C2 between the first and second throttle valve 69A, the 69B from main inlet air pathway B3 to above branch.On the second flow direction E2 as the flow direction of the auxiliary air among the secondary inlet air pathway C1, upstream extremity C2 is positioned at upstream side.

Figure 11 is the enlarged view of the right flank of secondary inlet air pathway organizator 91 peripheries.Figure 12 is the amplification view of secondary inlet air pathway organizator 91 peripheries.Figure 13 is a back elevation of observing secondary inlet air pathway organizator 91 peripheries from the rear side of vehicle.

With reference to Figure 12, the extension of second boss 92 is provided with the part that portion 98 constitutes intermediate member 99.Extend and portion 98 to be set according to extending with upstream extremity formation portion 97 perpendicular modes.Extend and portion 98 to be set along with more to the downstream extension of the second flow direction E2 and offside in the below.Space in the portion 98 is set to downstream C3 from extension, secondary inlet air pathway C1 is along with more to the downstream extension of the second flow direction E2 and offside in the below.It is offside in right-hand along with more rearward extending with respect to upstream extremity formation portion 97 that extension is provided with portion 98.

Flexible pipe 93 is formed and is constituted the part of intermediate member 99 by pliability materials such as rubber.On vehicle fore-and-aft direction X1, flexible pipe 93 is configured between upstream extremity formation portion 97 and the 3rd boss 94.In addition, on left and right vehicle wheel direction Y1, flexible pipe 93 is configured between the fixture 46 of left surface 22a and sparger 47 usefulness of cylinder head 22.

With reference to Figure 12 and Figure 13, flexible pipe 93 is being configured on the vehicle above-below direction Z1 between upstream extremity formation portion 97 and the 3rd boss 94.

Flexible pipe 93 comprises the first joint 93a, the 93b of first portion, second portion 93c, third part 93d, the 4th part 93e, the 5th part 93f and the second joint 93g.These first joints 93a, first～the 5th part 93b～93f and the second joint 93g are arranged in order along the second flow direction E2.

The extension that the first joint 93a embeds second boss 92 is provided with portion 98, uses not shown hose clip that the first joint 93a is fixed on this extension and is provided with in the portion 98.

On the second flow direction E2, it is offside in the below along with extending more downstream from extension 98 to the second joint 93g of portion to be set.

The 93b of first portion forms fan-shaped as a whole.The 93b of first portion is offside in right-hand along with more rearward extending since the first joint 93a.The 93b of first portion is configured in attachment portion right-hand of cylinder 64 and connecting tube 65 in planimetric map.The 93b of first portion forms the first area C11 of secondary inlet air pathway C1.

Second portion 93c forms U word shape as a whole.Second portion 93c in planimetric map with crooked to right-hand outstanding mode.Second portion 93c be configured in sparger 47 roughly directly over.Second portion 93c forms the second area C12 of secondary inlet air pathway C1.

Third part 93d forms the near linear shape.Third part 93d begins roughly to extend to left along left and right vehicle wheel direction Y1 from second portion 93c.Third part 93d with after the face G2 that states intersect.Third part 93d forms the 3rd zone C 13 of secondary inlet air pathway C1.

The 4th part 93e forms U word shape as a whole.As a whole with crooked to the outstanding mode of left, A1 is positioned at left to the 4th part 93e with respect to the vehicle center axis in planimetric map.The 4th part 93e rearward extends from third part 93d.The 4th part 93e forms the 4th zone C 14 of secondary inlet air pathway C1.The radius of curvature R 4 of the 4th part 93e is than the 2 big (R4＞R2) of the radius of curvature R of second portion 93c.

The 5th part 93f forms straight line shape as a whole.The 5th part 93f since the 4th part 93e roughly along left and right vehicle wheel direction Y1 to right-hand extension.The 5th part 93f intersects with vehicle center axis A1 and cylinder-bore axis A2 in planimetric map.The 5th part 93f forms the 5th zone C 15 of secondary inlet air pathway C1.

The second joint 93g forms straight line shape as a whole, and since the 5th part 93f along left and right vehicle wheel direction Y1 to right-hand extension.

With reference to Figure 11 and Figure 13, the first joint 93a, the 93b of first portion, second portion 93c, third part 93d and the 4th part 93e are with respect to the top configuration along vehicle above-below direction Z1 of cylinder 64 and connecting tube 65.In addition, the difference of height L4 of the secondary inlet air pathway C1 among the 4th part 93e is than the big (L4＞L2) of the difference of height L2 of the secondary inlet air pathway C1 among the second portion 93C.

In right hand view, flexible pipe 93 is along cylinder 64 and connecting tube 65 configurations.In addition, among the figure, flexible pipe 93 is arranged on the vehicle fore-and-aft direction X1 with cylinder 64 and connecting tube 65 overleaf.

In addition, among the 5th part 93f of flexible pipe 93, with respect to the addendum modification downwards of the unit length of flow direction E2 than among the third part 93d, big with respect to the addendum modification downwards of the unit length of flow direction E2.Thus, the difference of height L5 of the secondary inlet air pathway C1 among the 5th part 93f is than the big (L5＞L3) of the difference of height L3 of the secondary inlet air pathway C1 among the third part 93d.

With reference to Fig. 3 and Figure 12, the 3rd boss 94 is for the parts of metal L word shape and constitute the part of intermediate member 99.The 3rd boss 94 comprises and is configured to orthogonal 94a of first portion and second portion 94b.The 94a of first portion extends along left and right vehicle wheel direction Y1.On the 94a of first portion of the 3rd boss 94, be connected with the second joint 93g of flexible pipe 93.The second joint 93g with after the face G2 that states approximately perpendicular towards extension.Second portion 94b is with approximately perpendicular towards extension with the central axis J6 of jet space B2.

According to said structure, intermediate member 99 is formed by the 94a of first portion that the extension of second boss 92 is provided with portion 98, flexible pipe 93 and the 3rd boss 94.Upstream extremity C2 and the zone line C4 between the downstream C3 among the secondary inlet air pathway C1 have been formed through intermediate member 99.Zone line C4 is formed by the space C17 that extension is provided with in space C16 in the portion 98, the 94a of first portion of first～the 5th zone C 11～C15, the 3rd boss 94 in the flexible pipe 93.

The 4th boss 95 forms the part of the downstream C3 of secondary inlet air pathway C1.The 4th boss 95 and first boss 45 form and are tubular.The 4th boss 95 is to extend with the approximately perpendicular mode of central axis J6 of jet space B2.On the 4th boss 95, be fixed with the second portion 94b of the 3rd boss 94.Downstream C3 is communicated with chamber B1.Through the second portion 94b and the 4th boss 95 of the 3rd boss 94, be provided with the downstream formation portion 100 that forms downstream C3.

According to said structure, in the Zone Full of the second flow direction E2, secondary inlet air pathway C1 and the circle that the is shaped as perpendicular cross section of the second flow direction E2.The center line F1 of secondary inlet air pathway C1 extends to downstream C3 through the center in this cross section from upstream extremity C2.

With reference to Fig. 2 and Figure 12, on the second flow direction E2, stipulated to link an end F2 who is positioned at the upper reaches and the line segment G1 of the other end F3 that is positioned at downstream among the center line F1 of secondary inlet air pathway C1 with the shortest distance.In addition, stipulated to comprise the face G2 of this line segment G1.Face G2 is the face (specifically be plane) parallel with vehicle above-below direction Z1, for example is vertical guide.Line segment G1 is configured in the right-hand of vehicle center axis A1 in planimetric map, offside in the right side along with more rearward extending.In addition, in right hand view, line segment G1 is offside in the below along with more rearward extending.Through this structure, make the upstream extremity C2 of secondary inlet air pathway C1 and downstream C3 have difference of height.

With reference to Figure 12, the center line F13 of the secondary inlet air pathway C1 among the second area C13 intersects and this face of crosscut G2 with approximately perpendicular mode and face G2.

In addition, the center line F14 of the center line F12 of the center line F11 of the secondary inlet air pathway C1 among the C11 of first area, the secondary inlet air pathway C1 among the second area C12 and the secondary inlet air pathway C1 in the 4th zone C 14 is circular-arc respectively and is formed curved part respectively.The center line F11 of secondary inlet air pathway C1 among the C11 of first area and the center line F12 of the secondary inlet air pathway C1 among the second area C12 are configured in the right side of face G2.On the other hand, the center line F14 of the secondary inlet air pathway C1 in the 4th zone C 14 is configured in the left side of face G2.Therefore, be configured in the both sides of face G2 as center line F11, F12, the F14 of curved part.

In addition; In planimetric map; Promptly when in the behind of secondary inlet air pathway organizator 91 when engine main body 14 residing directions are observed, the third part 93d of the flexible pipe 93 of intermediate member 99 and the 5th part 93f stride the both sides as the cylinder-bore axis A2 of the central axis of engine main body 14.These third parts 93d and the 5th part 93f are as the linearity region of intermediate member 99 and be set up.

With reference to Figure 13; In addition; Overleaf among the figure,, dispose secondary inlet air pathway organizator 91 in the inboard of the configuring area D1 of the key element except secondary inlet air pathway organizator 91 of engine unit 13 promptly when in the behind of secondary inlet air pathway organizator 91 during from the residing directions observation of cylinder block 21.Specifically, overleaf among the figure, be configured in the position lower than the support that supports carburetor cable 74 120 as the upstream extremity formation portion 97 of the upper end of secondary inlet air pathway organizator 91.

Among the figure, be configured in the upside of cylinder head 22 as the 4th boss 95 of the lower end of secondary inlet air pathway organizator 91 overleaf.Overleaf among the figure, as the 4th part 93e of the flexible pipe 93 of the left end of secondary inlet air pathway organizator 91 compare with the left surface 20a of crankcase 20 be configured in right-hand.Overleaf among the figure, compare with sparger 47 as the second portion 93c of the flexible pipe 93 of the right-hand member of secondary inlet air pathway organizator 91 and to be configured in left.

According to this mode of execution, can obtain following action effect.That is, the center line F1 of secondary inlet air pathway C1 and face G2 intersect.Through such structure, secondary inlet air pathway C1 is wriggled extend.Thus, can prolong secondary inlet air pathway C1 fully.Thus, can guarantee enough to pass through resistance from the fluid of jet space B2 in secondary inlet air pathway C1.As a result, even blowing back of fuel taken place in jet space B2, also can make the fuel that is blown back be difficult to invade among the secondary inlet air pathway C1.

In addition, owing to be that the sinuous simple structure of extending of secondary inlet air pathway C1 is got final product, therefore can simply also realize at low cost being used for preventing that fuel from being blown the structure of getting back to secondary inlet air pathway C1.In addition, not through making the first and second throttle valve 69A, 69B increase the length of secondary inlet air pathway C1 away from cylinder head 22, but guarantee enough path lengths through making secondary inlet air pathway 91 wriggle to extend.Therefore, need not increase from the distance of the first and second throttle valve 69A, 69B B4 to the firing chamber.Thus, can realize good engine response to throttle operation.

In addition, got back among the secondary inlet air pathway C1 if fuel blows, the fuel that is then blown back can irrespectively flow to firing chamber B4 with the fuel injection control of sparger 47.Therefore, can cause deviation is appearred in the fuel duty of firing chamber B4.But,, therefore can suppress such deviation owing to suppressed blowing back of fuel.

In addition, not to increase the structure of fluid through resistance in the secondary inlet air pathway C1 through the section area that reduces secondary inlet air pathway C1.Therefore, can guarantee the necessary flow of air inlet reliably.

In addition, this three place of the center line F14 in center line F11, the center line F12 among the second area C12 and the 4th zone C 14 of the center line F1 of secondary inlet air pathway C1 in the C11 of first area is crooked.Therefore, the secondary inlet air pathway C1 of curved shape has bigger fluid and passes through resistance.Therefore, can suppress fuel is more reliably blown and is got back among the secondary inlet air pathway C1.

In addition, first area C11, second area C12 and the 4th zone C 14 are configured in the both sides of face G2.Thus, in the both sides of face G2, can guarantee fully that the fluid of secondary inlet air pathway C1 passes through resistance.Therefore, can not make secondary inlet air pathway C1 only form very longly at the one-sided of face G2.Thus, can make the overall compact of secondary inlet air pathway organizator 91.

And there are difference of height in upstream extremity C2 and downstream C3 on the second flow direction E2 among the secondary inlet air pathway C1.In addition, face G2 is the face (specifically being the plane) that parallels with vehicle above-below direction Z1, for example is vertical guide, and the 3rd zone C 13 as the part of secondary inlet air pathway C1 forms the cross-section G2 from upstream extremity C2 downstream end C3 at least.

Thus, can make the three-dimensional ground of secondary inlet air pathway C1 crooked.Therefore, even shortened the configuration of length of the line segment G1 at the two ends that link secondary inlet air pathway C1, can guarantee fully that also the fluid in the secondary inlet air pathway C1 passes through resistance.Therefore, throttle body 68 is more disposed near firing chamber B4 side.Thus, can further improve engine response to throttle operation.

In addition, the upstream extremity formation portion 97 of secondary inlet air pathway organizator 91 is connected with the top of the cylinder 64 of throttle body 68.Even on the inwall of cylinder 64, generated dew, also can suppress dew and attracted in the secondary inlet air pathway C1.In addition, be connected with the top 96 of cylinder 64, can further increase the difference of height of secondary inlet air pathway C1 through making secondary inlet air pathway organizator 91.As a result, easily secondary inlet air pathway C1 is configured to along with more to the downstream extension of the second flow direction E2 and offside in the below.

And the cylinder 64 of throttle body 68 is configured in the top of engine main body 14, and sparger 47 is configured in the upper surface side of cylinder head 22.Thus, the upstream extremity formation portion 97 of secondary inlet air pathway organizator 91 and downstream formation portion 100 all are configured in the upper surface side of engine main body 14.Therefore, be configured the operation of the flexible pipe 93 of secondary inlet air pathway organizator 91 easily.

In addition, among the secondary inlet air pathway C1 near upstream extremity C2 Zone Full form along with extending more downstream offside along the second flow direction E2 in the below.Thus, even in fuel has invaded secondary inlet air pathway C1 the time, also can be when motor stops etc. fuel promptly being discharged in secondary inlet air pathway C1 through gravity.Thus, can prevent that fuel from stockpiling in secondary inlet air pathway C1 and deterioration.

And, overleaf among the figure, dispose secondary inlet air pathway organizator 91 in the inboard of the configuring area D1 of the key element except secondary inlet air pathway organizator 91 of engine unit 13.Thus, can reduce the space that engine unit occupies as a whole.Therefore, can make the mobile engine unit compact.

In addition, the 94a of first portion of the 3rd boss 94 of intermediate member 99 is to be connected towards the second portion 94b with the 3rd boss 94 with face G2 is approximately perpendicular.Thus, can the second joint 93g that makes intermediate member 99 since the second portion 94b of the 3rd boss 94 with the approximate rear curved of extending as the crow flies of the approximately perpendicular direction of face G2.Thus, can under the short situation of the length of line segment G1, sufficiently increase the degree of the bending of secondary inlet air pathway C1.Thus, can make the first and second throttle valve 69A, 69B, realize high-engine response, and can guarantee the air flow resistance in the secondary inlet air pathway C1 fully and suppressed blowing back of fuel throttle operation near firing chamber B4.

And, in planimetric map, as the 3rd zone C 13 of the flexible pipe 93 of the linearity region of intermediate member 99 and the both sides that the 5th zone C 15 is striden cylinder-bore axis A2.Thus, form straight line shape with can making the 3rd zone C 13 and the 5th zone C 15 long enoughs, can guarantee easily that therefore the fluid of the necessity in the into secondary gas path C1 passes through resistance.

As stated, suppressed to be got back to the supply of fuel that causes among the secondary inlet air pathway C1 to the non-intention of fuel chambers B4 owing to fuel blows.Thus, can realize the combustion regime expected, and can realize the automotive bicycle 1 good the engine response of throttle operation.

(mode of execution two)

Below, with reference to accompanying drawing mode of execution two of the present invention is described.Below the front and back in the explanation, up and down, about all directions be that to be in the viewpoint that is equivalent to the benchmark posture of straightaway state on the horizontal plane and driver this driver during towards the place ahead with automotive bicycle 200 be benchmark.

In mode of execution two, the structure of automotive bicycle 200 and the structure of motor are different with above-mentioned mode of execution one.For also omitting explanation about structure, effect and effect with the mode of execution one identical identical label of structure mark.Figure 14 is the right hand view of the automotive bicycle 200 of this mode of execution two.Dispose handle 202 in the front portion of automotive bicycle 200.Handle 202 links via steering shaft 204 that runs through head pipe 203 and front-wheel 206.

Automotive bicycle 200 has vehicle frame 208.Vehicle frame 208 is the shape on vehicle fore-and-aft direction X1, extending as a whole.The front end of vehicle frame 208 links with head pipe 203.At the rear portion of vehicle frame 203 vehicle seat 211 is installed.Be equipped with on the part in the place ahead of the vehicle seat 211 in vehicle frame 208 and carry pedal plate 209.In addition, car cover 210 is installed on vehicle frame 208, this car cover 210 has shape of holding up to the top from the rear portion of carrying pedal plate 209 and the following side space that surrounds vehicle seat 211.Side support 306 is installed on vehicle frame 208.Side support 306 is used for support frame 208 when automotive bicycle 200 stops.

The engine unit 213 of unit oscillating is installed on vehicle frame 208.

Engine unit 21 is engine units of forced air cooling type.Engine unit 213 comprises engine main body 214, suction tude 262, throttle body 68, secondary inlet air pathway organizator 291 and guard shield (shroud) 300.

The crankcase of stating behind the engine main body 214 220 links via pivot 301 with vehicle frame 208, and the axis of this pivot 301 extends along the left and right vehicle wheel direction.In addition, via power transfering part 216 trailing wheel 215 is installed at the rear portion of engine unit 213.In addition, between the rear portion of power transfering part 216 and vehicle frame 208, rear shock absorber 218 is installed.Through this structure, engine unit 213 is can being fulcrum and the mode of on above-below direction, swinging with trailing wheel 215 is supported with pivot 301 with respect to vehicle frame 208.

Figure 15 is a right hand view of representing the part of engine unit 213 through the cross section.Engine main body 214 with cylinder-bore axis A201 approximately horizontally towards the state configuration in the place ahead.Engine main body 214 comprises crankcase 220, cylinder block 221, cylinder head 222.In crankcase 220, accommodate bent axle 223.Lamination has cylinder block 221 and cylinder head 222 successively on the antetheca of crankcase 220.These crankcases 220, cylinder block 221 and cylinder head 222 are used bolts etc. and are linked each other.

In the cylinder thorax 226 of cylinder block 221, can accommodate piston 227 with being free to slide.Piston 227 links via connecting rod 228 and bent axle 223.In addition, on bent axle 223, be connected with fan 302.Fan 302 through the rotation of bent axle 223 by being driven.Fan 302 for cooled engine main body 214 from the lateral of guard shield 300 inboard picked-up air, air is imported in the guard shield 300 as cooling air.On cylinder head 222, be formed with burning recess 229.Burning recess 229 is configured in the part place that engages with cylinder thorax 226 of cylinder head 222.Space between the burning recess 229 of cylinder head 222, cylinder thorax 226, the piston 227 is firing chamber B204.

On cylinder head 222, be formed with relief opening 232 and suction port 233.One end of relief opening 232 is through being communicated with firing chamber B204 to burning recess 229 openings.One end of suction port 233 is through being communicated with firing chamber B204 to burning recess 229 openings.The exhaust passageway B205 that relief opening 232 forms in the cylinder head 222.Exhaust passageway B205 extends downwards in cylinder head 222.The other end of exhaust passageway B205 is communicated with outlet pipe 234 interior exhaust passageways.On the other hand, the main inlet air pathway B232 in the suction port 232 formation cylinder head 222.

One end of relief opening 232 opens and closes with predetermined timing through being arranged on the outlet valve 236 on the cylinder head 222.In addition, an end of suction port 232 likewise opens and closes with predetermined timing through being arranged on the suction valve 237 on the cylinder head 222.

Guard shield 300 comprises that the integral body with cylinder block 221 spreads all over and surrounds allly and will spread all over the full cylindrical portion of surrounding 303 as the rearward end of the part of cylinder head 222 and from the side plate 304 of the right-hand covering crankcase 220 of crankcase 220 allly entirely.Cylindrical portion 303 has the upper wall 305 of the top that is configured in engine main body 214.The upper surface of upper wall 305 coating gas cylinder bodies 221.

Near the air inlet 232 on the right flank top of cylinder head 222, dispose the sparger 47 of the injection apparatus that acts as a fuel.

Figure 16 is the sectional view along the XVI-XVI line intercepting of Figure 15.With reference to Figure 16, the part of sparger 47 is contained in first boss 45 that is formed on the cylinder head 222.

First boss 45 forms and is equipped with sparger 47 with cylinder head 222.The inner space of first boss 45 is communicated with suction port 232.On first boss 45, sparger 47 is installed via plastic fixture 46.

Figure 17 is the planimetric map of engine unit 213.With reference to Figure 16 and Figure 17, be provided with engine side flange 259 at the upper surface of cylinder head 222.In planimetric map, the vehicle center axis A201 on the central axis of engine side flange 259 and the left and right vehicle wheel direction Y1 intersects.Main inlet air pathway B232 in the cylinder head 222 in cylinder head 222 to above extend.The other end of main inlet air pathway B232 in the cylinder head 222 is formed by engine side flange 259.In addition, in planimetric map, vehicle center axis A201 is consistent with cylinder-bore axis A202.

Figure 18 is the right hand view of the major component of engine unit 213.With reference to Figure 18, suction tude 262 forms the part of main inlet air pathway B203.Suction tude 262 is forwards extended from the rear on the vehicle fore-and-aft direction X1.Suction tude 262 comprises: be connected with air-strainer (not shown) and the air inlet that is configured to forwards extend with flexible pipe 263; The cylinder 64 that is connected with the front end of flexible pipe 263 with air inlet; And be connected and the reclinate connecting tube 265 of front end with the front end of cylinder 64.

Cylinder 64 is roughly extended along vehicle center axis A1 in the planimetric map of vehicle with connecting tube 265.

When right flank is observed automotive bicycle 201, cylinder 64 and connecting tube 265 are along with extending and offside in the below to vehicle front more.

With reference to Figure 16 and Figure 18, the suction tude side flange 267 and the engine side flange 259 of connecting tube 265 dock each other, and use fixing bolt to be fixed.Thus, the main inlet air pathway B231 in main inlet air pathway B232 in the cylinder head 222 and the suction tude 262 is communicated with, and has formed main inlet air pathway B203 as a whole.

Engine unit 13 is provided with throttle body 68.The cylinder 64 of throttle body 68 is configured in the top of the cylinder block 221 of engine main body 214, and is configured in the top of guard shield 300.

Main inlet air pathway B203 in the suction tude 262 is opened and closed through the first and second throttle valve 69A, 69B.

Engine unit 213 has secondary air inlet organizator 291.Secondary air inlet organizator 291 forms secondary inlet air pathway C201.Secondary inlet air pathway C201 imports to air inlet among the jet space B2 when idle running at least.Among the upstream extremity C202 of secondary inlet air pathway C201 and the main inlet air pathway B203 of suction tude 262, first throttle valve 69A is connected with zone between the second throttle valve 69B.In addition, the downstream C203 of secondary inlet air pathway C201 is connected with chamber B1.Secondary inlet air pathway C201 is through making auxiliary air and colliding the effect that promotes fuel atomization of bringing into play from sparger 47 injected fuel mutually.

Figure 19 is the planimetric map of the engine unit 13 of secondary inlet air pathway organizator 291 peripheries.Figure 20 is the front elevation of the engine unit 13 of secondary inlet air pathway organizator 291 peripheries.

With reference to Figure 18, first boss 45 forms with cylinder head 222.On first boss 45, sparger 47 is installed.On first boss 45, formed downstream formation portion 295.Downstream formation portion 295 extends with respect to the axis normal ground of sparger 47.The 3rd boss 294 is installed in downstream formation portion 295.Secondary inlet air pathway organizator 291 comprises: be fixed on second boss 292 on the cylinder 220, be formed on the downstream formation portion 295 on the cylinder head 222, the flexible pipe 293 that is installed in the 3rd boss 294 in the downstream formation portion 295 and connects the 3rd boss 294 and second boss 292.In this mode of execution, " secondary inlet air pathway C20 " is meant the space that is formed in second boss 292, flexible pipe 293, the 3rd boss 294 and the downstream formation portion 295.Passed through should pair inlet air pathway C201 auxiliary air be supplied to jet space B2 as " near the space the jet nozzles ".

Second boss 292 is the metal tubes that form the L word shape.Second boss 292 comprises the upstream extremity formation portion 297 on the top 96 of the cylinder 64 that is fixed on throttle body 68 and extends the extension that is provided with from upstream extremity formation portion 297 portion 298 is set.

Upstream extremity formation portion 297 forms the upstream extremity C202 of secondary inlet air pathway C201.Upstream extremity formation portion 297 is connected with the top 96 of the cylinder 64 of throttle body 68, and extends to the top from this top 96.Thus, upstream extremity C202 between the first and second throttle valve 69A, the 69B from main inlet air pathway B203 to above branch.On the second flow direction E2 as the flow direction of the auxiliary air among the secondary inlet air pathway C201, upstream extremity C202 is positioned at the upper reaches.

With reference to Figure 17, extend the part that the portion that is provided with 298 constitutes intermediate member 299.Extend and portion 298 to be set according to extending with upstream extremity formation portion 297 approximately perpendicular modes.It is offside in left along with more forwards extending with respect to upstream extremity formation portion 297 that extension is provided with portion 298.In addition, extend that portion 298 is set is offside in the below along with more forwards extending.

Flexible pipe 293 is formed and is constituted the part of intermediate member 299 by pliability materials such as rubber.On vehicle fore-and-aft direction X1, flexible pipe 293 is configured between the upstream extremity formation portion 297 and first boss 45.In addition, on left and right vehicle wheel direction Y1, flexible pipe 293 is configured between the right flank 303a of cylindrical portion 303 of left surface 222a and guard shield 300 of cylinder head 222.

With reference to Figure 19 and Figure 20, on the second flow direction E2, the integral body of extending the secondary inlet air pathway C201 afterwards of the portion that is provided with 298 is offside in the below along with extending more downstream.Flexible pipe 293 is being configured on the vehicle above-below direction Z1 between the upstream extremity formation portion 297 and first boss 45.

Flexible pipe 293 comprises the first joint 293a, the 293b of first portion, second portion 293c, third part 293d, the 4th part 293e, the 5th part 293f, the 6th part 293g and the second joint 293h.These first joints 293a, first～the 6th part 293b～293g and the second joint 293h are arranged in order along the second flow direction E2.

The extension that the first joint 293a embeds second boss 292 is provided with portion 298, uses not shown hose clip that the first joint 293a is fixed on this extension and is provided with in the portion 298.

On the second flow direction E2, the second joint 293h is positioned at the below since the first joint 293a along with extending downstream.Thus, on the second flow direction E2, the whole zone of intermediate member 299 is offside in the below along with extending more downstream.

The 293b of first portion forms straight line shape as a whole.The 293b of first portion is offside in left along with more forwards extending since the first joint 293a.The 293b of first portion is configured in the left of the attachment portion of cylinder 64 and connecting tube 265 in planimetric map.The 293b of first portion forms the first area C211 of secondary inlet air pathway C201.

Second portion 293c forms L word shape as a whole.Second portion 293c is crooked with the mode of giving prominence to left in planimetric map.Second portion 293c forms the second area C212 of secondary inlet air pathway C201.

Third part 293d forms the near linear shape.Third part 293d is offside in right-hand along with more forwards extending.Third part 293d forms the 3rd zone C 213 of secondary inlet air pathway C201.

The 4th part 293e forms L word shape as a whole.The 4th part 293e is crooked with forwards outstanding mode as a whole in planimetric map.The 4th part 293e rearward extends from third part 293d.The 4th part 293e with approximately perpendicular mode with after the face G202 that states intersect and cross-section G202.The 4th part 293e forms the 4th zone C 214 of secondary inlet air pathway C201.

With reference to Figure 18 and Figure 19, the 5th part 293f forms the near linear shape.The 5th part 293f since the 4th part 293e along with more rearward extending more to right-hand extension.The 5th part 293f forms the 5th zone C 215 in the flexible pipe 293.

The 6th part 293g forms U word shape as a whole.When left and right vehicle wheel direction Y1 observes, the 6th part 293g as a whole and crooked with rearward outstanding mode.The 6th part 293g forms the 6th zone C 216 of secondary inlet air pathway C201.

The second joint 293h forms the near linear shape, and offside in left along with more forwards extending since the 6th part 293g.

With reference to Figure 18 and Figure 20, on vehicle above-below direction Z1, the first joint 293a, first～the 5th part 293b～293f are with respect to the top configuration near vehicle above-below direction Z1 of cylinder 64 and connecting tube 265.In addition, the difference of height L206 of the secondary inlet air pathway C201 among the 6th part 293g is than the big (L206＞L205) of the difference of height L205 of the secondary inlet air pathway C201 among the first joint 293a～the 5th part 293f.

In right hand view, flexible pipe 293 is near cylinder 64 and connecting tube 265 configurations.

With reference to Figure 16 and Figure 19, the 3rd boss 294 is a metal cartridge and a part that constitutes intermediate member 299.The 3rd boss 294 is to extend with the perpendicular mode of the central axis J6 of jet space B2.On the 3rd boss 294, be connected with the second joint 293h of flexible pipe 293.The 3rd boss 294 on the second flow direction E2 along with extending more downstream offside in below.

According to said structure, intermediate member 299 is provided with portion 298, flexible pipe 293 and the 3rd boss 294 by the extension of second boss 292 and forms.Upstream extremity C202 and the zone line C4 between the downstream C203 among the secondary inlet air pathway C201 have been formed through intermediate member 299.Zone line C204 is provided with space C217 in the portion 298, first area C211～the 6th zone C 216 in the flexible pipe 293, the space C218 in the 3rd boss 294 by extension and forms.

Downstream formation portion 295 forms the downstream C203 of secondary inlet air pathway C201.The downstream formation portion 295 and first boss 45 form and are tubular.Downstream formation portion 295 to be extending with the approximately perpendicular mode of central axis J6 of jet space B2, and on the second flow direction E2 along with extending more downstream offside in below.Downstream C203 is communicated with chamber B1.

According to said structure, in the Zone Full of the second flow direction E2, secondary inlet air pathway C201 and the circle that the is shaped as perpendicular cross section of the second flow direction E2.The center line F201 of secondary inlet air pathway C201 extends to downstream C203 through the center in this cross section from upstream extremity C202.

With reference to Figure 18 and Figure 19, on the second flow direction E2, stipulated to link an end F202 who is positioned at the upper reaches and the line segment G201 of the other end F203 that is positioned at downstream among the center line F201 of secondary inlet air pathway C201 with the shortest distance.In addition, stipulated to comprise the face G202 of this line segment G201.Face G202 is the face (specifically being the plane) that parallels with vehicle above-below direction Z1, for example is vertical guide.Line segment G201 is configured in the right-hand of vehicle center axis A201 in planimetric map, offside in the right side along with more forwards extending.In addition, in right hand view, line segment G201 is offside in the below along with more forwards extending.Through this structure, make the upstream extremity C202 of secondary inlet air pathway C201 and downstream C203 have difference of height.

The center line F214 of secondary inlet air pathway C201 in the 4th zone C 214 forms with face G202 and intersects.

In addition, the center line F216 of the center line F214 of the secondary inlet air pathway C201 in the center line F212 of the secondary inlet air pathway C201 among the second area C212, the 4th zone C 214 and the secondary inlet air pathway C201 in the 6th zone C 216 is circular-arc respectively and is formed curved part respectively.The center line F214 of secondary inlet air pathway C201 in the center line F212 of secondary inlet air pathway C201 among the second area C212 and the 4th zone C 214 is configured in the left side of face G202.On the other hand, the center line F216 of the secondary inlet air pathway C201 in the 6th zone C 216 is configured in the right side of face G202.Therefore, be configured in the both sides of face G202 as center line F212, F214, the F216 of curved part.

In addition; With reference to Figure 20; In front elevation; Promptly when in the behind of secondary inlet air pathway organizator 291 when cylinder block 221 residing directions are observed, dispose secondary inlet air pathway organizator 291 in the inboard of the configuring area D201 of the key element except secondary inlet air pathway organizator 291 of engine unit 213.Specifically, in front elevation, be configured in the position lower than the support that supports carburetor cable 74 320 as the upstream extremity formation portion 297 of the upper end of secondary inlet air pathway C201.

In front elevation, be configured in the top of cylinder head 222 as the downstream formation portion 295 of the lower end of secondary inlet air pathway organizator 291.In front elevation, compare the inboard that is configured in the guard shield 300 on the left and right vehicle wheel direction Y1 with the left surface 303a of the cylindrical portion 303 of guard shield 300 as the second portion 293c of the flexible pipe 293 of the left end of secondary inlet air pathway organizator 291.In front elevation, be configured in the inboard of the engine main body 214 on the left and right vehicle wheel direction Y1 with respect to the fixture 46 of sparger 47 as the 6th part 293g of the flexible pipe 293 of the right-hand member of secondary inlet air pathway organizator 291.

With reference to Figure 20, in the front elevation of vehicle, the center line F213 of third part 293d that has stipulated flexible pipe 293 is with respect to the tilt angle theta of substantially horizontal.Angle θ is greater than the angle of inclination that is supported on the posture on the horizontal H 1 from the orthostatism of vehicle frame shown in Figure 20 to that kind shown in figure 21 through side support 306.At this moment, the downstream C203 of secondary inlet air pathway C201 is positioned at the position lower than upstream extremity C202.

Even supporting through side support 306 under the state of automotive bicycle 200, flexible pipe 293 also in spreading all over the scope of total length, remain along with more to the downstream extension of the second flow direction E2 and offside in below shape.Therefore, can be suppressed at the fuel that has liquefied in the cylinder head 222 flows backwards to throttle body 68.

In addition, on cylinder block 221, be fixed with metal clip 307.Clip 307 has the holding part 308 of approximate C word shape.The third part 293d of flexible pipe 293 and this holding part 308 tablings, the shape of flexible pipe 293 is held.The third part 293d of flexible pipe 293 is positioned at the approximate center part on the second flow direction E2 of flexible pipe 293.

According to this mode of execution, can obtain following action effect.That is, the center line F201 of secondary inlet air pathway C201 and face G202 intersect.Through such structure, secondary inlet air pathway C201 is wriggled extend.Thus, can prolong secondary inlet air pathway C201 fully.Thus, can guarantee enough to pass through resistance from the fluid of jet space B2 in secondary inlet air pathway C201.As a result, even blowing back of fuel taken place in jet space B2, also can make the fuel that is blown back be difficult to invade among the secondary inlet air pathway C201.In addition, owing to be that the sinuous simple structure of extending of secondary inlet air pathway C201 is got final product, therefore can simply also realize at low cost being used for preventing that fuel from being blown the structure of getting back to secondary inlet air pathway C201.

In addition, not through making the first and second throttle valve 69A, 69B increase the length of secondary inlet air pathway C201, but guarantee enough path lengths through secondary inlet air pathway C201 being wriggled extend away from cylinder head 22.Therefore, need not increase from the distance of the first and second throttle valve 69A, 69B B204 to the firing chamber.Thus, can realize good engine response to throttle operation.

In addition, got back among the secondary inlet air pathway C201 if fuel blows, the fuel that is then blown back can irrespectively flow to firing chamber B204 with the fuel injection control of sparger 47.Therefore, can cause deviation is appearred in the fuel duty of firing chamber B204.But,, therefore can suppress such deviation owing to suppressed blowing back of fuel.

In addition, not to increase the structure of fluid through resistance in the secondary inlet air pathway C201 through the section area that reduces secondary inlet air pathway C201.Therefore, can guarantee the necessary flow of air inlet reliably.

In addition, this three place of center line F211, center line F214 in four zone C 214 and the center line F216 in six zone C 216 of the center line F201 of secondary inlet air pathway C201 in second area C212 is crooked.The secondary inlet air pathway C201 of curved shape has bigger fluid and passes through resistance.Therefore, can suppress fuel is more reliably blown and is got back among the secondary inlet air pathway C201.

In addition, second area C212, the 4th zone C 214 and the 6th zone C 216 are configured in the both sides of face G202.Thus, in the both sides of face G202, can guarantee fully that the fluid of secondary inlet air pathway C201 passes through resistance.Therefore, can not make secondary inlet air pathway C201 only form very longly at the one-sided of face G202.Thus, can make the overall compact of secondary inlet air pathway organizator 291.

And there are difference of height in upstream extremity C202 and the downstream C203 of the second flow direction E2 among the secondary inlet air pathway C201.In addition, face G202 is the face (specifically being the plane) that parallels with vehicle above-below direction Z1, for example is vertical guide, and the 4th zone C 214 of secondary inlet air pathway C201 forms the cross-section G202 from upstream extremity C202 downstream end C203.

Thus, can make the three-dimensional ground of secondary inlet air pathway C201 crooked.Therefore, even shortened the configuration of the length of the line segment G2 that links upstream extremity C202 and downstream C203, can guarantee fully that also the fluid in the secondary inlet air pathway C201 passes through resistance.Therefore, throttle body 68 is more disposed near firing chamber B204 side.Thus, can further improve engine response to throttle operation.

In addition, the upstream extremity formation portion 297 of secondary inlet air pathway organizator 291 is connected with the top of the cylinder 64 of throttle body 68.Thus, even on the inwall of suction tude 262, generated dew, also can suppress dew and attracted in the secondary inlet air pathway C201.In addition, be connected with the top 96 of cylinder 64, can further increase the difference of height of secondary inlet air pathway C201 through making secondary inlet air pathway organizator 291.As a result, easily the major part of secondary inlet air pathway C201 is configured to along with more to the downstream extension of the second flow direction E2 and offside in the below.

And the cylinder 64 of throttle body 68 is configured in the top of engine main body 214, and sparger 47 is configured in the upper surface side of cylinder head 22.Thus, the upstream extremity formation portion 297 of secondary inlet air pathway organizator 291 and downstream formation portion 295 all are configured in the upper surface side of engine main body 214.Therefore, dispose the flexible pipe 293 of secondary inlet air pathway organizator 291 easily.

In addition, among the secondary inlet air pathway C201 near upstream extremity C202 Zone Full be configured to along with extending more downstream offside along the second flow direction E2 in the below.Thus, even in fuel has invaded secondary inlet air pathway C201 the time, also can be when motor stops etc. fuel promptly being discharged in secondary inlet air pathway C201 through gravity.Thus, can prevent that fuel from stockpiling in secondary inlet air pathway C201 and deterioration.

And, in front elevation, dispose secondary inlet air pathway organizator 291 in the inboard of the configuring area D201 of the key element except secondary inlet air pathway organizator 291 of engine unit 213.Thus, can reduce the space that engine unit occupies as a whole.Therefore, can make the mobile engine unit compact.

Thus, can suppress to be got back to the supply of fuel that causes among the secondary inlet air pathway C201 to the non-intention of fuel chambers B204 owing to fuel blows.Thus, the combustion regime of expectation can be reached, and the automotive bicycle 200 good can be realized the engine response of throttle operation.

In addition, realized following design: even supporting through side support 305 under the state of automotive bicycle 200, also can be suppressed at the fuel that has liquefied in the cylinder head 222 and in secondary inlet air pathway C201, flow backwards.

And the shape of flexible pipe 293 that forms the secondary inlet air pathway organizator 291 of secondary inlet air pathway C201 is kept by clip 307.Thus, even when inclination has taken place vehicle frame 208, also can keep the shape of flexible pipe 293.

The invention is not restricted to the mode of execution that is illustrated through foregoing description and accompanying drawing, following mode of execution is also included within the technical scope of the present invention.And, except following manner, can also in the scope that does not break away from purport, carry out various changes.Below, to also omitting explanation to structure, effect and effect with mode of execution one or the mode of execution two identical identical labels of structure mark.

(1) also can that kind shown in figure 22 near the upstream extremity C2 of secondary inlet air pathway C1 installation as the leaf valve 310 of one-way valve.In this case, leaf valve 310 comprises housing 311, is provided with the break 315 that the supporting element 313 of the opening 312 of fluid, the reed 314 that opens and closes opening 312 and restriction reed 314 move in central authorities.Reed 314 uses bolt 316 with break 315 and is maintained on the supporting element 313.Housing 311 is provided with the upstream side joint 316 of tubular and the downside joint 317 of tubular.Upstream side joint 316 is connected with second boss 92 via flexible pipe 318.In addition, on downside joint 317, be connected with the flexible pipe 93 of intermediate member 99.Open through reed 314 bendings, opening 312, auxiliary air can flow out to the second flow direction E2.On the other hand, on the direction opposite with the second flow direction E2, because reed 314 can become the state of choked flow through hole 312, so fluid can not flow to the direction opposite with the second flow direction E2.

Thus, the air inlet that flow into the jet space B2 from main inlet air pathway B3 can be passed through secondary inlet air pathway C1.In addition, can prevent to be blown back and the fuel that in secondary inlet air pathway C1, flows backwards passes through.And, can will be maintained the resistance that passes through that low state improves the fuel that in secondary inlet air pathway C1, flows backwards simultaneously from the resistance that passes through that main inlet air pathway B3 flow into air inlet the jet space B2.

(2) secondary inlet air pathway is not limited to stringing on the upper surface of air-strainer and cylinder head, also can be in the side stringing.

(3) quantity of the curved part in the secondary inlet air pathway also can be for more than three, and is unqualified to its quantity.

(4) curved part also can only be configured in the one-sided of face.

(5) position below secondary inlet air pathway organizator also can lean at the upper surface than cylinder is connected with cylinder.

(6) intermediate member also can be vertical with face with the joint of upstream extremity formation portion.

(7) in addition, when on the ground in level through side support under the posture that tilts during support frame, the integral body of secondary inlet air pathway also can for level towards.

(8) secondary inlet air pathway organizator so long as form getting final product with the parts that are formed on the secondary inlet air pathway that the jet space in the cylinder head couples together between first and second throttle valve also can be and above-mentioned mode of execution various structure.For example, also can omit the 3rd boss and the other end of flexible pipe is embedded in the 4th boss or the downstream formation portion fixes.In addition, also can omit the 4th boss or downstream formation portion, and on first boss, form recess and the 3rd boss is embedded in this recess and fix.In addition, also can omit the 3rd boss and the 4th boss (downstream formation portion) and the end of flexible pipe directly is fixed on first boss.In addition, also can on the cylinder of throttle body, form recess and the end of flexible pipe is fixed in this recess.Also can form secondary inlet air pathway at interval through in pipe, being provided with.

(9) in mode of execution one, the face G2 on the plane that conduct and vehicle above-below direction Z1 parallel has been described, but face G2 can be any towards.For example, also can that kind shown in figure 23 through secondary inlet air pathway organizator 91 being configured in left with respect to engine main body 14 or right-hand (in Figure 23, being left) the face G2 of making becomes the perpendicular face with vehicle above-below direction Z1.

Likewise, in mode of execution two, the face G202 on the plane that conduct and vehicle above-below direction Z1 parallel has been described, but face G202 can be any towards.For example, also can that kind shown in figure 24 through secondary inlet air pathway organizator 291 being configured in left with respect to engine main body 214 or right-hand (in Figure 24 for right-hand) the face G202 of making becomes the perpendicular face with vehicle above-below direction Z1.

(10) in mode of execution one, secondary inlet air pathway 91 is formed by second boss 92, flexible pipe 93, the 3rd boss 94 and the 4th boss 95, but is not limited to this structure.For example, can consider that also that kind shown in figure 25 is through being fastened on second boss 92 on the throttle body 68 and the 3rd boss 94 that has been fixed with respect to cylinder head 22 and forming " secondary inlet air pathway C21 " with these boss 92,94 various parts.In this case, " secondary inlet air pathway C21 " formed by flexible pipe 93." jet nozzles 47b near space " be meant on the flow direction E2 of air inlet than flexible pipe 93 lean on downstream, up to space in the face of the position of jet nozzles 47b.

In this case, secondary inlet air pathway organizator 491 is the flexible pipes 93 that form forniciform parts as at least a portion.Between an end of cylinder 64 and flexible pipe 93, second boss 92 forms communication paths C20.Communication paths C20 is communicated with the main inlet air pathway B3 and the secondary inlet air pathway C21 that is formed by flexible pipe 93 between the first and second throttle valve 69A, the 69B.In addition, on flow direction E2, leaning on the space up in the face of the position of jet nozzles 47b in downstream than flexible pipe 93 is near the space B 21 the jet nozzles 47b.

The line segment G11 of an end F22 who has stipulated to link the upper reaches that are positioned at flow direction E2 among the center line F21 of secondary inlet air pathway C20 and the other end F23 that is positioned at downstream with the shortest distance.The face G21 that comprises line segment G11 for example is the plane that parallels with vehicle above-below direction Z1.Center line F21 and this face G21 of secondary inlet air pathway G20 intersect.In this case, also can obtain effect and the effect identical with mode of execution one.With in above-mentioned (9), explained identical, face G21 towards be not limited to vehicle above-below direction Z1 parallel towards, can be any towards.

In addition, in mode of execution two, secondary inlet air pathway 291 forms portion 295 by second boss 292, flexible pipe 293, the 3rd boss 294 and downstream and forms, but is not limited to this structure.For example, also can that kind shown in figure 26 through being fastened on second boss 292 on the throttle body 68 and the 3rd boss 294 that has been fixed with respect to cylinder head 222 and forming " secondary inlet air pathway C221 " with these boss 292,294 various parts.In this case, " secondary inlet air pathway C221 " formed by flexible pipe 293.In addition, " jet nozzles 47b near space " be meant on the flow direction E2 of air inlet than flexible pipe 293 lean on downstream, up to space in the face of the position of jet nozzles 47b.

In this case, secondary inlet air pathway organizator 591 is the flexible pipes 293 that form forniciform parts as at least a portion.Between an end of cylinder 64 and flexible pipe 293, second boss 292 forms communication paths C220.Communication paths C220 is communicated with the main inlet air pathway B203 and the secondary inlet air pathway C221 that is formed by flexible pipe 293 between the first and second throttle valve 69A, the 69B.In addition, on flow direction E2, leaning on the space up in the face of the position of jet nozzles 47b in downstream than flexible pipe 293 is near the space B 221 the jet nozzles 47b.

The line segment G211 of an end F222 who has stipulated to link the upper reaches that are positioned at flow direction E2 among the center line F221 of secondary inlet air pathway C221 and the other end F223 that is positioned at downstream with the shortest distance.The face G212 that comprises line segment G211 for example is the plane that parallels with vehicle above-below direction Z1.Center line F221 and this face G212 of secondary inlet air pathway G221 intersect.In this case, also can obtain effect and the effect identical with mode of execution two.With in above-mentioned (9), explained identical, face G212 towards be not limited to vehicle above-below direction Z1 parallel towards, can be any towards.

In the mode of execution of the mode of execution of Figure 25 and Figure 26, explained that the miscellaneous part that is used to connect throttle body and cylinder head is the example of flexible pipe, but be not limited to flexible pipe, also can be metallic pipe or in pipe, be provided with at interval.

Claims (15)

1. mobile engine unit comprises:

Engine main body has cylinder head, the part of the part of this cylinder head formation firing chamber and the main inlet air pathway that is connected with said firing chamber;

Suction tude forms said main inlet air pathway with said cylinder head connection and with said cylinder head;

Throttle body has in said suction tude devices spaced apart on the flow direction of air inlet and two throttle valve disposing and form the part of said suction tude and hold the cylinder of said two throttle valve;

Fuel injection system is installed on the said cylinder head, has the jet nozzles of the said main inlet air pathway burner oil in said cylinder head; And

Secondary inlet air pathway organizator forms secondary inlet air pathway, and this pair inlet air pathway is communicated with said main inlet air pathway between said two throttle valve, is characterised in that:

Said secondary inlet air pathway is at least near the space when idle running imports to said air inlet said jet nozzles; And said secondary inlet air pathway organizator forms the center line of said secondary inlet air pathway and comprises that the face with lower line segment intersects, and said line segment links an end and the other end of said center line with the shortest distance.

2. mobile engine as claimed in claim 1 unit, wherein,

Said center line has two curved parts at least.

3. mobile engine as claimed in claim 2 unit, wherein,

Said curved part is configured in said both sides.

4. mobile engine as claimed in claim 1 unit, wherein,

Said face is the face that parallels with the vehicle above-below direction.

5. mobile engine as claimed in claim 4 unit, wherein,

Upstream extremity and downstream on the flow direction of the said air inlet in the said secondary inlet air pathway have difference of height,

The part of said secondary inlet air pathway forms along with extending and said of crosscut to said downstream from said upstream extremity.

6. mobile engine as claimed in claim 1 unit, wherein,

Said secondary inlet air pathway organizator is connected with the top of the said cylinder of said throttle body.

7. mobile engine as claimed in claim 1 unit, wherein,

The said cylinder of said throttle body is configured in the top of said engine main body,

Said fuel injection system is configured in the upper surface side of said cylinder head.

8. mobile engine as claimed in claim 1 unit, wherein,

The distolateral at least a portion in the downstream of said secondary inlet air pathway is offside in the below along with extending more downstream along the flow direction of the said air inlet in the said secondary inlet air pathway.

9. mobile engine as claimed in claim 1 unit, wherein,

When from being arranged on the residing position of cylinder block on the said engine main body when the behind of said secondary inlet air pathway organizator is observed, said secondary inlet air pathway organizator is configured in the inboard of configuring area of the key element except said secondary inlet air pathway organizator of said mobile engine unit.

10. mobile engine as claimed in claim 1 unit, wherein,

Said secondary inlet air pathway organizator comprises: form the upstream extremity on the flow direction of the said air inlet in the said secondary inlet air pathway upstream extremity formation portion, form the downstream formation portion of the downstream on the flow direction of the said air inlet in the said secondary inlet air pathway and form said upstream extremity and the intermediate member of the zone line between the said downstream in the said secondary inlet air pathway

Said intermediate member with said approximately perpendicular towards with said upstream extremity formation portion and said downstream formation portion at least one be connected.

11. mobile engine as claimed in claim 10 unit, wherein,

When from the residing position of said engine main body when the behind of said secondary inlet air pathway organizator is observed, said intermediate member has the linearity region of the both sides of the central axis of striding said firing chamber.

12. mobile engine as claimed in claim 1 unit, wherein,

Said secondary inlet air pathway organizator also has one-way valve, and the anti-fluid of this one-way valve moves to the direction opposite with the flow direction of said air inlet in said secondary inlet air pathway.

13. a Straddle-type vehicle comprises:

Vehicle frame; And

By each described mobile engine unit in the claim 1 to 12 of said vehicle frame support.

14. Straddle-type vehicle as claimed in claim 13, wherein,

Also comprise the side support that is used to support said vehicle frame,

When the posture that tilts with said vehicle frame through said side support on the ground in level supports said Straddle-type vehicle, the integral body of said secondary inlet air pathway be level towards, or the downstream of said secondary inlet air pathway be positioned at the position lower than upstream extremity.

15. Straddle-type vehicle as claimed in claim 13, wherein,

Said secondary inlet air pathway organizator comprises:

Flexible pipe has pliability and forms at least a portion of said secondary inlet air pathway; And

Clip keeps the shape of said flexible pipe.

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