CN109236440A - The configuration structure and motorcycle of exhaust gas sensor - Google Patents

Abstract

The present invention is the configuration structure and motorcycle of exhaust gas sensor.The present invention improves exhaust purification performance, and can without detriment to exhaust gas ingredient detection accuracy configure exhaust gas sensor.The present invention has: having the cylinder (21a) in the front for being configured at crankcase (20) and the engine (2) of cylinder head (21b)；It is installed on the exhaust pipe (6) of the exhaust port (22) of cylinder head；It is configured at the catalytic unit (50) of the midway of exhaust pipe；And the upstream side senser (8) of exhaust pipe is installed in the upstream side of catalytic unit.For the axis of cylinder towards general horizontal direction, exhaust port is set to the downside of cylinder head.Exhaust pipe, which has, matches pipe portion (62) in the lower section of cylinder head extending along the width of the car first.Catalytic unit is configured at first with pipe portion in a manner of being axially facing vehicle width direction.

Description

The configuration structure and motorcycle of exhaust gas sensor

Technical field

The present invention relates to the configuration structure of exhaust gas sensor and motorcycles.

Background technique

With exhaust limitation of today, in the exhaust system of mobile engine, it is desirable that urge purification exhaust gas Disguise the degradation set to be monitored.For example, in patent document 1, being equipped in the downstream side of catalytic unit to exhaust gas The lambda sensor that is detected of oxygen concentration.

Specifically, in patent document 1, the inside of muffler is divided by multiple next doors (separator), formed multiple swollen Swollen room.Catalytic unit is configured in the inside of muffler, the downstream of catalytic unit, which extends up to, to be projected into defined expanding chamber. In addition, each expanding chamber and catalytic unit are connect with multiple exhaust pipes.Lambda sensor is mounted to the downstream side of perforation catalytic unit Exhaust pipe.

Existing technical literature

Patent document

Patent document 1: Japanese Unexamined Patent Publication 2016-160914 bulletin

Subject to be solved by the invention

However, in patent document 1, a part recess of the outer wall of muffler is made to configure lambda sensor.As a result, The volume of expanding chamber and the amount of recess of outer wall correspondingly become smaller, the worry for having the erasure effect of exhaust gas to reduce.In addition, row Gas gas more then temperature more declines toward downstream, therefore, from catalytic unit, lambda sensor Temperature Activity from the viewpoint of, whether there is or not Method ensures properly to detect the worry of the oxygen concentration of exhaust gas while exhaust purification performance.

Summary of the invention

The present invention is completed in view of above-mentioned point, and its purpose is to provide a kind of configuration structures of exhaust gas sensor And motorcycle, configure exhaust gas biography while exhaust purification performance raising and the detection accuracy of lossless exhaust gas ingredient can be made Sensor.

Means for solving the problems

In the configuration structure of the exhaust gas sensor of a mode of the invention, have: engine, which, which has, matches It is placed in the cylinder and cylinder head in the front of crankcase；Exhaust pipe, the exhaust pipe are installed on the exhaust port of the cylinder head；Catalysis Device, the catalytic unit are configured at the midway of the exhaust pipe；And first exhaust gas sensor, the first exhaust gas pass Sensor is located at the upstream side of the catalytic unit and is installed on the exhaust pipe, and the axis of the cylinder is towards approximate horizontal side It is set to the downside of the cylinder head to, the exhaust port, the exhaust pipe has first to match pipe portion, this first exists with pipe portion It is extended along the width of the car below the cylinder head, the catalytic unit is configured at described in a manner of being axially facing vehicle width direction First matches pipe portion.

Invention effect

In accordance with the invention it is possible to improve exhaust purification performance, and without detriment to the detection accuracy of exhaust gas ingredient Configure exhaust gas sensor.

Detailed description of the invention

Fig. 1 is the outline structure for indicating to apply the motorcycle of the configuration structure of exhaust gas sensor of present embodiment Right side view.

Fig. 2 is the right side view for indicating the engine peripheral structure of motorcycle shown in FIG. 1.

Fig. 3 is the figure that a part of structure is omitted from Fig. 2.

Fig. 4 is the bottom view of engine peripheral structure shown in Fig. 2.

Fig. 5 is the figure that a part of structure is omitted from Fig. 4.

Fig. 6 is the main view of engine peripheral structure shown in Fig. 2.

Fig. 7 is the perspective view of the exhaust system of present embodiment.

Fig. 8 is the top view on the exhaust pipe periphery of present embodiment.

Fig. 9 is the A direction view of Fig. 8.

The explanation of symbol

1 motorcycle

2 engines

20 crankcases

21a cylinder

21b cylinder head

22 exhaust ports

3 body shells (frame)

4 engine suspension frame brackets (bracket)

50 catalytic units

6 exhaust pipes (exhaust pipe)

61 first bending sections

62 first match pipe portion

63 second bending sections

64 second match pipe portion

8 upstream side sensers (first exhaust gas sensor)

9 downstream side sensers (second exhaust gas sensor)

Specific embodiment

Hereinafter, referring to attached drawing, detailed description of embodiments of the present invention.In the following, to will be of the invention The example that the configuration structure of exhaust gas sensor is applied to pedal motorcycle is illustrated, but application is not limited to this, And it can change.For example, it is also possible to which the configuration structure of exhaust gas sensor of the invention is applied to other kinds of motor Vehicle, the automatic tricycle of cross-country type, automatic carriage etc..In addition, about direction, respectively by arrow FR indicate vehicle front, Rear of vehicle is indicated by arrow RE, vehicle up direction is indicated by arrow UP, is indicated to indicate vehicle below vehicle, by arrow L by arrow LO Left direction indicates vehicle right direction by arrow R.In addition, in each figure below, it is for ease of description, clipped Structure.

Referring to Fig.1, the outline structure of the motorcycle of present embodiment is illustrated.Fig. 1 is to indicate to apply this implementation The right side view of the outline structure of the motorcycle of the configuration structure of the exhaust gas sensor of mode.

As shown in Figure 1, the motorcycle 1 of miniature pedal type is configured to body shell 3 (referring to Fig. 2) suspension hair in bending beam type Motivation 2.Engine 2 is made of such as single-cylinder engine.Especially in the present embodiment, using engine 2, speed changer (after The cvt unit etc. stated) and to rear-wheel 26 transmission mechanism and the integrated unit oscillating engine of swing arm.

The various covers as vehicle body exterior trim are installed in body shell and engine 2.Specifically, being equipped in vehicle front side Leg shield 11 around the leg of front protection driver.Central frame cover 12 is equipped at the rear of leg shield 11.In The lower end of centre frame cover 12 is provided with the foot pedal 13 rearward extended.Covering vehicular sideview is equipped at the rear of foot pedal 13 Side frame cover 14.

Front fork 15 is rotatably supported in vehicle front via steering shaft (not shown).It is equipped with and uses in the top of front fork 15 In the handle 17 for carrying out steering to front-wheel 16.Front-wheel 16 is rotatably supported in the lower part of front fork 15.

Seat 18 is equipped in the upside of side frame cover 14.Rear baffle 19 is equipped at the rear portion of side frame cover 14.From side frame The inside of cover 14 spreads the engine 2 to rear configured as internal combustion engine.

Engine 2 extends in the longitudinal at the rear of foot pedal 13.The front end portion of engine 2 is linked to body shell 3, and It is configured to using the linking portion as fulcrum, engine 2 is whole to be swung up and down.Rear-wheel 26 is rotationally arranged at engine 2 Rear end.

Exhaust pipe 6 and silencer 7 are connected with as exhaust system in the exhaust port 22 (referring to Fig. 4,5) of engine 2.Row Tracheae 6 extends engine 2 underneath towards rear.Silencer 7 is connected to the rear end of exhaust pipe 6, and side is configured to when observing It is Chong Die with rear-wheel 26.Muffler cover 70 is equipped in the right side of silencer 7.

Then, referring to Fig. 2 to Fig. 6, the engine and its peripheral structure of present embodiment are illustrated.Fig. 2 is to indicate The right side view of the engine peripheral structure of motorcycle shown in FIG. 1.Fig. 3 is the figure that a part of structure is omitted from Fig. 2.Figure 4 be the bottom view of engine peripheral structure shown in Fig. 2.Fig. 5 is the figure that a part of structure is omitted from Fig. 4.Fig. 6 is Fig. 2 Shown in engine peripheral structure main view.

As described above, the engine 2 of present embodiment unit as used by the motorcycle 1 (referring to Fig.1) of pedal-type is put The motor mechanism of dynamic formula at.As shown in Figures 2 to 6, engine 2 is swingably suspended in vehicle via engine suspension frame bracket 4 Body frame 3.

Body shell 3 is configured to: the lower frame 30 extended in the longitudinal below foot pedal 13 (referring to Fig.1)；From A pair of side frames 31 that the rear end of lower frame 30 extends towards back upper place；And the company of connection lower frame 30 and a pair of side frames 31 Tie frame 32.

Lower frame 30 is in the front lower place of engine 2 to pass through the substantial middle of the vehicle width direction (center line of aftermentioned cylinder On C1) mode extend in the longitudinal.Framework 32 is connected with the rear end of lower frame 30, prolongs along vehicle width direction (left and right directions) It stretches.The lower end of a pair of side frames 31 is connected to the left and right ends of framework 32.

Engine 2 is configured to configure in order in the front of the crankcase 20 of the various structure members such as receiving crankshaft (not shown) Cylinder 21a, cylinder head 21b and valve mechanism cover 21c.Cylinder 21a is configured in such a way that axis is towards general horizontal direction forward It rolls oblique.

Specifically, direction is slightly got higher relative to horizontal direction for the front side (side valve mechanism cover 21c) of the axis of cylinder 21a Direction (general horizontal direction).That is, the horizontal direction of present embodiment does not mean only that fully horizontal direction, this is not being departed from It is the concept with defined amplitude in the range of the purport of invention.

Cylinder 21a is installed on the front of crankcase 20.The columned cylinder bore of receiving piston is formed in the inside of cylinder 21a (combustion chamber) (not shown).Cylinder head 21b is installed on the front of cylinder 21a.It is formed with and combustion chamber in cylinder head 21b Air inlet port (not shown) and exhaust port 22.Exhaust port 22 is set to the downside (following side) of cylinder head 21b, exhaust end Mouth 22 has axial in vertical direction.

Valve mechanism cover 21c is installed on the front of cylinder head 21b, plays the role of lid in cylinder head 21b.In cylinder head 21b And inside receiving air intake-exhaust door (not shown) of valve mechanism cover 21c and the valve mechanism of driven for opening and closing air intake-exhaust door (are not schemed Show).

Crankcase 20 is configured to the left case 23 and right case 24 divided by connections such as bolt or so.Left case 23 and right case 24 The axis center that joint surface passes through cylinder.In Fig. 4, axis center (left case 23 and the right case 24 by cylinder are indicated by center line C1 Joint surface) straight line.Crankshaft is accommodated in crankcase 20, crankshaft is configured to axial in the vehicle width direction in level.In Fig. 4, by The center of center line C2 expression crankshaft.

Particularly, left case 23 extends towards rear, after rear-wheel 26 is rotatably mounted in left case 23 via gear-box 27 End.That is, left case 23 constitutes the swing arm of cantilever support rear-wheel 26.The left side of left case 23 is open, and accommodates and makees in the inside of left case 23 For the cvt unit (not shown) of speed changer.Cvt unit is made of the stepless transmission of so-called belt, passes through the winding of change tape Radius realizes speed change.Hood 25 is installed in the left of left case 23, the opening of left case 23 is blocked for.It is accommodated in gear-box 27 Reduction gearing (not shown).

In addition, being formed in left case 23 and right case 24 outstanding in the engine of body shell 3 for engine 2 to be linked (suspension) Frame portion 23a, 24a.Engine suspension frame portion 23a, 24a is from left case 23 and the respective lower surface of right case 24 towards the lower section of cylinder 21a Ground is formed towards front protrusion.23a, 24a are configured side by side in the vehicle width direction in engine suspension frame portion, opposite across center line C1. The top of engine suspension frame portion 23a, 24a constitute the swinging axle (hinge portion) of engine 2.

In engine suspension frame portion, 23a, 24a are equipped with a pair of of engine suspension frame bracket 4.Engine suspension frame bracket 4 is from starting The top of machine suspended portion 23a, 24a extends towards front.A pair of of engine suspension frame bracket 4 and starts in the lower section of cylinder head 21b The accordingly configuration side by side in the vehicle width direction of machine suspended portion 23a, 24a, and it is opposite across center line C1.

The rear end part of engine suspension frame portion 23a, 24a and engine suspension frame bracket 4 passes through axis extending along the width of the car Portion 40 and swingably link.The tip portion of engine suspension frame bracket 4 is consolidated via suspension tube 41 extending along the width of the car Due to framework 32.

The cooling fan 28a coaxial with crankshaft is equipped on the right side of crankcase 20.Cooling fan 28a is by being set to right case 24 Right side fan guard 28 cover.Cooling fan 28a is the fan of engine forced air-cooling, is taken into fan guard 28 outer Gas cools down cylinder 21a and cylinder head 21b.

Silencer 7 is connected to the exhaust port 22 of engine 2 via exhaust pipe 6.It is generated by the burning of engine 2 Exhaust gas is discharged after 7 noise reduction of silencer from exhaust port 22 by exhaust pipe 6.About exhaust pipe 6 it is detailed After describe.

Then, referring to Fig. 7 to Fig. 9, the exhaust system of present embodiment is illustrated.Fig. 7 is the row of present embodiment The perspective view of gas system.Fig. 8 is the top view on the exhaust pipe periphery of present embodiment.Fig. 9 is the A direction view of Fig. 8.

As shown in fig. 7, the exhaust system of present embodiment be configured to include: be connected to exhaust port 22 (referring to Fig. 4,5) Exhaust pipe 6；It is connected to the silencer 7 of the downstream of exhaust pipe 6.As shown in Figure 7 to 9, exhaust pipe 6 is installed via flange 60 In the exhaust port 22 of engine 2 (cylinder head 21b (referring to Fig. 5)).

After exhaust pipe 6 protrudes downwards from exhaust port 22, to general horizontal direction right lateral bending when the observation of front.And And side, when observing, exhaust pipe 6 extends along engine 2 and fan guard 28 (referring to Fig. 2,3) underneath towards rear.

Specifically, exhaust pipe 6, which is formed as from the upstream side successively the first bending section of solder joints 61, first, matches pipe portion 62, pipe portion 64 is matched in the second bending section 63, second.After first bending section 61 from flange 60 with extending downward, to the right substantially The front observation L-shaped shape of right-angle bending.That is, the first bending section 61 makes the row of vertical direction in the first upstream side with pipe portion 62 Air-flow road direction horizontal direction (left and right directions) bending.In addition, the first bending section 61 is by will be in direction, that is, Fig. 5 intersecting axially In front-rear direction on dividing body (the first half and latter half of) solder bond divided and formed.In addition, 61 shape of the first bending section As with towards downstream and flowing path section becomes larger.

First is connected to the downstream of the first bending section 61 with pipe portion 62, and in cylinder 21a and cylinder head 21b (referring to Fig. 2 It is extended along the width of the car below to the joint surface of Fig. 5).First cuts the flow path of the downstream of the first bending section 61 with pipe portion 62 The size in face remains constant and has the cylindrical shape extended to the right.In addition, first with pipe portion 62 by will with axial direction The direction of intersection, dividing body (the upper half and lower half) solder bond divided in Fig. 7 in the up-down direction and formed.It chats later It states in detail, but is equipped with the catalytic unit 50 of purification exhaust gas with pipe portion 62 first.

Second bending section 63 is connected to the first downstream for matching pipe portion 62, has rearward approximate right angle after protruding to the right L-shaped shape when the curved overlook view in ground.That is, the second bending section 63 keeps vehicle width direction (left in the second downstream side with pipe portion 64 Right direction) exhaust flow path be bent forward and backward.In addition, the second bending section 6 is by will be in direction intersecting axially, Fig. 7 In dividing body (the upper half and lower half) solder bond divided in the up-down direction and formed.In addition, 63 shape of the second bending section As with towards downstream and flowing path section becomes smaller.

Second is connected to the downstream of the second bending section 63 with pipe portion 64, small with the flow diameter for matching pipe portion 62 than first Diameter extends to rear of vehicle.More specifically, when the observation of side shown in Fig. 2, second is shaped generally as V word with pipe portion 64 Shape.Second with pipe portion 64 from the upstream end of the second bending section 63 to after extending to the back lower place, in the lower section of fan guard 28 in crankshaft The heart nearby slight curvature and extends rearwardly and upwardly upwards.

There is silencer 7 outer diameter and exhaust pipe 6 to be comparably sufficiently big cylindrical shape.Specifically, silencer 7 is configured to By the head 7a for constituting upstream end, the rear for being connected to head 7a housing section 7b and be connected to housing section 7b rear tail portion 7c solder joints form.

The bowl-type shape that head 7a has rear open, is connected to the downstream of exhaust pipe 6.Housing section 7b has and head The connected cylindrical shape in the open end of portion 7a, extends towards rear.The bowl-type shape that tail portion 7c has front open, is engaged in shell The downstream of body portion 7b.The catalytic unit 51 of purification exhaust gas is equipped in silencer 7.

It is equipped in the part of the rear end part from exhaust pipe 6 to head 7a and the substantially first half of housing section 7b for that will arrange Tracheae 6 and silencer 7 are fixed on the bracket 71 of body side.In addition, being equipped with disappearing for protection silencer 7 in the right side side of silencer 7 Sound device cover 70.

As described above, configuration purifies the catalytic unit 50,51 of exhaust gas in the midway of exhaust pipe 6 and silencer 7.It urges Makeup is set 50,51 and is made of such as three-way catalytic apparatus, by exhaust gas polluter (carbon monoxide, hydrocarbon, Nitrogen oxides etc.) it is converted into harmless substance (carbon dioxide, water, nitrogen etc.).

In addition, being equipped with upstream side senser 8 and downstream side in exhaust pipe 6 in the upstream side and downstream side of catalytic unit 50 Exhaust gas sensor of the sensor 9 as the predetermined component in detection exhaust gas.Narration is detailed later, but upstream side senses Device 8 is set to the first bending section 61, and downstream side senser 9 is set to second with pipe portion 64.

Upstream side senser 8 and downstream side senser 9 are by for example detecting the oxygen as the predetermined component in exhaust gas Zirconium oxide formula lambda sensor is constituted.Upstream side senser 8 and downstream side senser 9 are formed to have the cylinder of defined length Shape, one end become test section, and another side is connect with wiring (not shown).Side senser 8 and downstream side senser 9 in upstream In, according to the oxygen concentration in exhaust gas, export (current value) variation.The current value is output to ECU (not shown) (Electronic Control Unit/ electronic control unit).In addition, exhaust gas sensor is not limited to lambda sensor, it can also To be such as air-fuel ratio sensor.

Various movements in ECU overall control motorcycle 1.ECU by the various processing in execution motorcycle 1 program, deposit Reservoir etc. is constituted.Memory is depending on the application and by ROM (Read Only Memory/ read-only memory), RAM (Random Access Memory/ random access memory) etc. storage mediums constitute.Each portion of control motorcycle 1 is stored in memory Control program etc..Particularly, in the present embodiment, ECU implements catalytic unit 50 based on the output of exhaust gas sensor Deterioration judging.For example, upstream side senser 8 and downstream side senser 9 it is dense it is dilute between the ratio of output reversion number determine The deterioration of catalytic unit 50.In addition, the deterioration in order to determine catalytic unit 50, is not limited to the feelings of the ratio using output reversion number The output difference of upstream side senser 8 and downstream side senser 9 also can be used in condition.

However as described above, in the exhaust system of motorcycle, it is desirable that the catalytic unit as row's gas cleaning plant Degradation be monitored.In order to implement the deterioration judging of catalytic unit, need to be arranged in the upstream and downstream of catalytic unit Exhaust gas sensor.

Such as previous implementation such as under type: by being set to the exhaust gas sensor of the upstream side of catalytic unit, (oxygen is passed Sensor) oxygen concentration in exhaust gas is detected, controlling air-fuel ratio.However, if for the purpose of the deterioration judging of catalytic unit, And when the downstream side of catalytic unit also configures exhaust gas sensor, since the distinctive layout of motorcycle restricts, it is ensured that regulation Detection accuracy while keep exhaust gas sensor relatively difficult close to the downstream side of catalytic unit.

This puts in the car, due to that can have configuration catalytic unit in place more than needed in equal spaces in engine room, Configuration, the protection of exhaust gas sensor are easier.On the other hand, more to be configured in chamber, silencer in motorcycle Catalytic unit, as described above, being difficult to be configured to exhaust gas sensor close to catalytic unit in structure.In addition, even if arranging The midway of tracheae configures catalytic unit, and the exhaust pipe situation close with circumferential component is more, it is difficult to ensure for configuring exhaust gas The space of body sensor.Further, it since the exhaust system of motorcycle is exposed in outside, also assumes that in such as winter, rain It when driving, the case where temperature of catalytic unit is easy decline and can not suitably obtain sensor output.In addition, exhaust gas The protection of sensor is also problematic.

For example, consideration keeps outer wall depression true in the case where catalytic unit is arranged in the muffler of chamber, silencer etc. Protect the configuration space of exhaust gas sensor.However, the volume reducing of chamber, silencer, as a result, having to original function The worry that (output increase, noise reduction) has an impact.

In addition, it is also contemplated that catalytic unit itself is configured to the front side of vehicle, but the configuration space of script catalytic unit Ensure just more difficult, in addition to this needs significantly design for change, therefore unrealistic.Further, it can generate following various The project of various kinds: catalytic unit thermal damage's caused by jockey, the decline of output, exhaust gas sensor as heat source Guard method, deterioration of appearance design etc..

Especially in the motorcycle of miniature pedal type, the row of arranging in the narrow space between engine, frame is needed Tracheae, exhaust pipe are set as thinner tube diameter.In this case, it is ensured that while the gap of circumferential component in exhaust pipe It is extremely difficult to configure catalytic unit, exhaust gas sensor.

In addition, considering directly to configure exhaust gas sensor in silencer in motor scooter.However, in silencer (in expanding chamber) causes to be difficult to correctly detect oxygen concentration by exhaust gas sensor, therefore due to the turbulent flow of exhaust gas Meet the performance of exhaust gas sensor with being unable to fully.Further, more toward the temperature of the downstream of exhaust flow path then exhaust gas More decline.Therefore, it according to the layout of exhaust gas sensor, is needed until the active temperature region for reaching exhaust gas sensor Time.This becomes the reason of exhaust gas sensor is difficult to work in the cold state of engine.In addition, if matching in silencer Setting exhaust gas sensor, then exhaust gas sensor is located at rear of vehicle, therefore the wiring of exhaust gas sensor is elongated, has Wiring complication, the increased worry of fixed position.

I.e., it is difficult to which the benchmark for meeting the exhaust body limitation for becoming stringent from now on not can avoid catalysis to reach the benchmark The enlargement of device.As its countermeasure, catalytic unit is configured near exhaust port by consideration as much as possible, but closer to exhaust Port then the configuration of exhaust pipe, the configuration of other component (exhaust gas sensor etc.) restriction become stringent.Especially in Fig. 2 institute That shows is suspended in engine 2 in the lower section of cylinder 21a and cylinder head 21b in the small-sized motor of the lower suspension type of body shell 3 Che Zhong, the restriction are tightened up.

Therefore, the present inventor makes exhaust pipe 6 in the motorcycle 1 of miniature pedal type below cylinder head 21b A part (first match pipe portion 62) be extended along the width of the car, first in pipe portion 62 along being configured axially catalytic unit 50. Further in the upstream side of the catalytic unit 50, exhaust port 22 just under exhaust pipe 6 (the first bending section 61) be configured with Upstream side senser 8.

According to this structure, catalytic unit 50 and upstream side senser 8 can be configured to close to the cylinder 21a as heat source And cylinder head 21b.Therefore, after the starting of engine 2, heatable catalytic device 50 and upstream side senser 8 it can make it as soon as possible Activate.Thereby, it is possible to improve exhaust purification performance, and also improve the detection accuracy of exhaust gas ingredient.In addition, The configuration freedom of circumferential component can also improved, engine 2 can be made compact.

Then, referring to Fig. 2 to Fig. 7, the configuration structure of catalytic unit and exhaust gas sensor to present embodiment into Row explanation.

As shown in Figures 2 to 7, catalytic unit 50 is configured at first with pipe portion 62 in a manner of being axially facing vehicle width direction. In addition, though it is not shown, but become dual pipe knot with small space is formed between pipe portion 62 and catalytic unit 50 first Structure.Therefore, the first heat with pipe portion 62 and catalytic unit 50 is difficult to transmit outward.Thereby, it is possible to inhibit the heat waste for jockey Wound.

In addition, as shown in figure 4, catalytic unit 50 is matched in the center line C1 of the axis center by cylinder 21a with by second Between the center line C3 of the axis center of pipe portion 64 positioned at exhaust port 22 just under.Therefore, catalytic unit can be made as much as possible 50 are configured to close to exhaust port 22.

In addition, constituting first by two dividing bodies matches pipe portion 62, the first bending section 61 and the second bending section 63, so as to It is enough that first is formed on the basis of first passing through punch process in advance to shape two dividing bodies with pipe portion 62, the first bending section 61 and the Two bending sections 63.

In particular, the first bending section 61 and the second bending section 63 be configured to front and back segmentation or up and down segmentation, i.e., by with It provides to be divided into two in the parallel plane of the plane of respective bending direction, to be bent the feelings to be formed with linear pipe is made Condition is compared, and the first bending section 61 and the bending radius of the second bending section 63 can be made to become smaller.Even if as a result, by the first bending section 61 And second bending section 63 be sharply bent and can also correspond to, the freedom degree of layout improves.As a result, can be in exhaust port 22 It is formed about with sharply curved exhaust pipe 6.Thus, it is also possible to be configured at catalytic unit 50 closer to exhaust port 22.

In addition, catalytic unit 50 is configured at cylinder head 21b and engine suspension frame bracket 4 when side view shown in Fig. 2 is observed Between.Therefore, even the engine 2 of lower suspension type, also catalytic unit 50 can be configured in the just lower of cylinder head 21b.Separately Outside, the front of catalytic unit 50 is surrounded by body shell 3, and rear is surrounded by crankcase 20, and top is surrounded by cylinder head 21b, under Side is surrounded by engine suspension frame bracket 4.Thus, it is not necessary to which by the covering of dedicated cover catalytic unit can be protected from slungshot, water etc. 50, and in appearance unobtrusively.

Upstream side senser 8 is installed on the bending part of the first bending section 61 from left.Specifically, in the first bending section Welded nut 80 on the divisional plane in 61 left side.By configuring nut 80 on divisional plane, thus it is easy to ensure that welded nut 80 When seat surface.Upstream side senser 8 is screwed into nut 80 with one end side, and top penetrates through in exhaust pipe 6 (the first bending section 61) Mode install.Thereby, it is possible to detect the exhaust gas flowed in the first bending section 61 by upstream side senser 8.

When especially, from the end on observation of exhaust port 22, the top of upstream side senser 8 is set to and exhaust port 22 The position of (flange 60) overlapping.In this way, which the top of upstream side senser 8 is located at exhaust port 22 relatively, even if as a result, Catalytic unit 50 be configured at cylinder head 21b just under, upstream side senser 8 can be also configured near exhaust port 22.It is tied Fruit is that upstream side senser 8 is promoted to activate as early as possible, improves the detection accuracy of exhaust gas ingredient.

It is axial parallel with catalytic unit 50 and coaxially match in addition, upstream side senser 8 is axially facing vehicle width direction It sets.In addition, upstream side senser 8 and catalytic unit 50 are configured to clip exhaust port 22 when overlooking.Further, upstream side senses Device 8 is configured in the width of cylinder head 21b below exhaust port 22 and is configured between a pair of of engine suspension frame bracket 4. Upstream side senser 8 is also identical as catalytic unit 50, and front is surrounded by body shell 3, and rear is surrounded by crankcase 20, top quilt Cylinder head 21b is surrounded, and lower section is surrounded by engine suspension frame bracket 4.Thus, it is not necessary to by dedicated cover covering can from slungshot, Water etc. protects upstream side senser 8, and in appearance unobtrusively.

In addition, catalytic unit 50 and upstream side senser 8 are configured at hinge portion (top of engine suspension frame portion 23a, 24a) Near.Therefore, the amount of movement of the swing of the adjoint engine 2 of catalytic unit 50 and upstream side senser 8 can be made to become smaller, it can Prevent the interference with circumferential component.In particular, the wiring of upstream side senser 8 can be easily processed.

Downstream side senser 9 is installed on the second first half for matching pipe portion 64 from right.Specifically, matching pipe portion 64 second Right side side welded nut 90.To be screwed into the one end of downstream side senser 9 in the nut 90, downstream side senser 9 Top perforation second is installed with the mode in pipe portion 64.Thereby, it is possible to match pipe portion 64 second by the detection of downstream side senser 9 The exhaust gas of interior flowing.

In addition, downstream side senser 9 is configured at center (the cooling fan 28a of crankshaft when side shown in Fig. 2 is observed Center) front and lower section.Further, downstream side senser 9 is axially facing vehicle width direction, and top is towards in vehicle width direction Side.That is, downstream side senser 9 is set to the side opposite with upstream side senser 8 across center line C1.In this way, make The top of side senser 8 and downstream side senser 9 is swum both facing to vehicle interior side, so as to make each sensor top detection Portion is configured closer to exhaust port 22.Thereby, it is possible to detect exhaust gas, detection accuracy in exhaust-gas upstream side as much as possible It improves.

In this way, which in the present embodiment, by two exhaust gas sensors, (upstream side senser 8 and downstream side are passed Sensor 9) it is configured at the upstream side i.e. exhaust pipe 6 of silencer 7, so as to not reduce the capacity of silencer 7, just in catalytic unit 50 upstream and detected downstream exhaust gas.Thereby, it is possible to detect the exhaust gas before spreading in silencer 7, detection essence Degree improves.

In addition, in the above-described embodiment, being illustrated by taking single-cylinder engine 2 as an example, but it is not limited to the structure.Example Such as, engine 2 can also be made of multicylinder engines more than two cylinders, and the configuration of each cylinder can also suitably change.

In addition, in the above-described embodiment, constituting body shell 3 by the frame of lower beam type, but be not limited to the structure.Vehicle Body frame 3 is also possible to the frame of such as diamond type, two-beam type.

In addition, in the above-described embodiment, being illustrated by taking the engine 2 of unit oscillating as an example, but be not limited to The structure.The other kinds of engine that engine is also possible to crankcase and swing arm is made up of different parts.

In addition, in the above-described embodiment, the structure for being formed as cylindrical shape to silencer 7 is illustrated, but unlimited Due to the structure.Silencer 7 also can have such as rectangular section, other odd-shaped cross sections.

In addition, in the above-described embodiment, first with pipe portion 62 is the knot for linking the dividing body divided up and down and being formed Structure, but it is not limited to the structure.First can also only be formed by cylindric pipe with pipe portion 62.

In addition, being to make exhaust pipe 6 along the structure on the right side of engine 2, but be not limited to the knot in the above-described embodiment Structure.The bending direction of exhaust pipe 6 can suitably change, for example, it can be make exhaust pipe 6 along the structure in the left side of engine 2.

In addition, in the above-described embodiment, the first bending section 61 is made up of front and back segmentation, first with pipe portion 62 and the Two bending sections 63 are constituted and dividing up and down, but are not limited to the structure, can be suitably changed.First bending section 61 and second Bending section 63 will be constituted by being divided into the component of two parts to be combined together, and can be changed according to bending direction. In addition, first can also divide composition by front and back with pipe portion 62.

In addition, being the knot of the right side installation downstream side senser 9 from second with pipe portion 64 in the above-described embodiment Structure, but it is not limited to the structure.Downstream side senser 9 for example can also be installed from the right side of the second bending section 63.In the feelings Under condition, it is preferred that welded nut 90 and be screwed into downstream side senser in the nut 90 on the divisional plane of the second bending section 63 9。

In addition, in the above-described embodiment, engine 2 is suspended in vehicle body in the lower section of cylinder 21a and cylinder head 21b For the unit oscillating engine of the lower suspension formula of frame 3, but it is not limited to the structure.For example, it can be in cylinder 21a and Engine 2 is suspended in the unit oscillating engine of the upper suspension-type of body shell 3 by the top of cylinder head 21b.

It, can also be in addition, present embodiment and variation are illustrated, but as other embodiments of the invention By above embodiment and variation entirety or part combination.

It, without departing from the spirit and scope of the invention can be into addition, the present invention is not limited to above-mentioned embodiments The various changes of row, displacement, deformation.Further, if can by the other technologies of progress or the derivation of technology, thus by Other methods realize technical idea of the invention, this method can be used also to implement.Therefore, the scope of the present invention covers this hair All embodiments that can include in the range of bright technical idea.

Industrial applicibility

As described above, the present invention, which has the effect that, so that exhaust purification performance is improved, and can be lossless In exhaust gas ingredient detection accuracy configure exhaust gas sensor, especially in the exhaust gas that can be applied to motorcycle It is useful in the configuration structure of sensor.

Claims (12)

1. a kind of configuration structure of exhaust gas sensor, has:

Engine, the engine have the cylinder and cylinder head in the front for being configured at crankcase；

Exhaust pipe, the exhaust pipe are installed on the exhaust port of the cylinder head；

Catalytic unit, the catalytic unit are configured at the midway of the exhaust pipe；And

First exhaust gas sensor, the first exhaust gas sensor are located at the upstream side of the catalytic unit and are installed on institute Exhaust pipe is stated, the configuration structure of the exhaust gas sensor is characterized in that,

The axis of the cylinder is set to the downside of the cylinder head towards general horizontal direction, the exhaust port,

The exhaust pipe has first to match pipe portion, this first is extended along the width of the car below the cylinder head with pipe portion,

The catalytic unit is configured at described first with pipe portion in a manner of being axially facing vehicle width direction.

2. the configuration structure of exhaust gas sensor according to claim 1, which is characterized in that

There is the exhaust pipe upstream side for matching pipe portion described first to make curved first bending section of exhaust flow path,

First bending section by by the dividing body divided on direction intersecting axially in conjunction with and formed.

3. the configuration structure of exhaust gas sensor according to claim 1 or 2, which is characterized in that

Also there is bracket, the bracket by the engine suspension frame in frame,

The bracket is set to the lower section of the cylinder head,

The catalytic unit is configured between the cylinder head and the bracket.

4. the configuration structure of exhaust gas sensor according to claim 2, which is characterized in that

The first exhaust gas sensor is installed on first bending section,

When from the end on observation of the exhaust port, the top of the first exhaust gas sensor and the exhaust end are salty It is folded.

5. the configuration structure of exhaust gas sensor according to claim 1 or 2, which is characterized in that

The first exhaust gas sensor is axial parallel with the catalytic unit and is configured to coaxial.

6. the configuration structure of exhaust gas sensor according to claim 1 or 2, which is characterized in that

When overlook view, the first exhaust gas sensor and the catalytic unit are configured to two positioned at the exhaust port Side.

7. the configuration structure of exhaust gas sensor according to claim 1 or 2, which is characterized in that

The first exhaust gas sensor is configured in the width of the cylinder head below the exhaust port.

8. the configuration structure of exhaust gas sensor according to claim 3, which is characterized in that

The bracket is equipped with a pair side by side in the vehicle width direction,

The first exhaust gas sensor is configured between a pair of bracket below the exhaust port.

9. the configuration structure of exhaust gas sensor according to claim 1 or 2, which is characterized in that

It is also equipped with second exhaust gas sensor, which is installed in the downstream side of the catalytic unit The exhaust pipe,

The front and lower section at center of the second exhaust gas sensor arrangement in crankshaft.

10. the configuration structure of exhaust gas sensor according to claim 9, which is characterized in that

The second exhaust gas sensor is across the cylinder arrangement in opposite with the first exhaust gas sensor one Side,

The top of the first exhaust gas sensor and the second exhaust gas sensor is towards inside.

11. the configuration structure of exhaust gas sensor according to claim 9, which is characterized in that

The exhaust pipe includes

Second bending section, second bending section are bent exhaust flow path in the described first downstream side with pipe portion；And

Second matches pipe portion, this second is connected to the downstream side of second bending section with pipe portion,

Second bending section be by being divided into the component of two parts to be combined together to form,

The second exhaust gas sensor is installed on second bending section or described second with pipe portion.

12. a kind of motorcycle, which is characterized in that have:

The configuration structure of exhaust gas sensor of any of claims 1-11.