CN1590729A - In cylinder fuel oil jet type IC engine - Google Patents

Abstract

To provide a cylinder injection internal combustion engine with excellent ignitability for improving combustion efficiency and improving fuel consumption without enlarging a cavity, by separating a tip firing part of an ignition plug from a jet flow of a fuel injection valve and bringing the tip firing part close to a center axis of the cavity. In the cylinder injection internal combustion engine, a combustion chamber 8 is formed between a piston 5 in which the cavity 51 is formed in a top surface thereof and a cylinder head 3, and a lower wall surface of the cylinder head 3 is a ceiling surface of the combustion chamber 8. A plurality of intake and exhaust valves, the fuel injection valve 60, an ignition plug 70 are disposed to face the combustion chamber 8. The ignition plug 70 is inserted from a side surface of the cylinder head 3 toward the combustion chamber 8, and the tip firing part 71 thereof is inclined with respect to the cylinder axis L1 and approximated to the center axis L1. The fuel injection valve 60 is inserted from an upper surface of the cylinder head 3 toward the combustion chamber 8 and inclined on a side approximately opposite to the ignition plug 70 with respect to the cylinder axis L1, and a tip nozzle 62a thereof is separated in an inclination direction from the center axis L1 of the cavity 51.

Description

In-cylinder injection fuel oil type internal-combustion engine

Technical field

The present invention relates to the in-cylinder injection fuel oil type internal-combustion engine of the spark ignition type of the chamber burner oil that a kind of Fuelinjection nozzle near the firing chamber forms towards the end face at piston.

Background technique

In order to improve the fuel efficiency of internal-combustion engine, in-cylinder injection fuel oil type internal-combustion engine, even adopt air fuel ratio whole in the firing chamber thinning, the stratification combustion manner that is also to form partly in the chamber that the end face of piston forms the dense mixing gas-bearing formation of air fuel ratio, lights a fire at this mixing gas-bearing formation.

For this reason, adopt the structure of the chamber burner oil that Fuelinjection nozzle forms in the face of the firing chamber, to the end face at piston, the mixing gas-bearing formation mid point fire (for example, with reference to patent documentation 1) that spark plug can be in being formed at chamber.

(patent documentation 1) spy opens flat 11-200867 communique

Disclosed in-cylinder injection fuel oil type internal-combustion engine is following structure in this patent documentation 1: oil sprayer (Fuelinjection nozzle) vertically inserts with cylinder-bore axis above cylinder head abreast, in the face of the firing chamber from the nozzle of front end to cylinder-bore axis direction burner oil, accept this jet flow at the chamber that the end face of piston forms.

, be supported on obliquely on the cylinder head with respect to the cylinder axis tape in the face of the spark plug of firing chamber with this oil sprayer, the igniting portion of spark plug is positioned at the mixing gas-bearing formation on the chamber of the piston that is formed at upper dead center.

Owing to oil sprayer sensing cylinder-bore axis direction and to cylinder-bore axis direction burner oil, so in order to accept this jet flow, do not form the mixed gas layer in the chamber of the end face of piston partially, oil sprayer slightly is positioned at the central shaft (with the parallel axle of cylinder-bore axis at center by chamber) of chamber.

In addition, spark plug need be avoided jet flow and dispose in order to make the jet flow disorder of oil sprayer.

Thereby, the igniting portion of the front end of spark plug, be positioned at the central shaft that departs from chamber chamber end edge portion and dispose.

Because the igniting portion of spark plug is positioned at the end edge portion of chamber,, the unsettled danger that becomes of lighting a fire is arranged then so light a fire at the ora terminalis of the mixing gas-bearing formation that is formed at chamber.

In addition, if make the spark plug of the posture of inclination leave the central shaft of chamber, only make the igniting portion of its front end be positioned at chamber, then chamber self becomes big, can not expect to improve fuel efficiency.

Summary of the invention

The present invention is in view of these problem points, its purpose is to provide a kind of in-cylinder injection fuel oil type internal-combustion engine, avoid the jet flow of Fuelinjection nozzle and near the central shaft of chamber by head-end ignition portion with spark plug, make ignitability well also can improve combustion efficiency, simultaneously, do not increase chamber self and just be expected to improve fuel efficiency.

In order to achieve the above object, the present invention's 1 in-cylinder injection fuel oil type internal-combustion engine, be that top end forms between the piston and cylinder head of chamber, in the firing chamber that the lower wall surface with described cylinder head forms as end face, Fuelinjection nozzle and spark plug with a plurality of suction air valves in the face of combustion chamber configuration; Described spark plug inserts to described firing chamber from the side of cylinder head, tilts with respect to cylinder-bore axis and also disposes head-end ignition portion near the central shaft of described chamber; Described Fuelinjection nozzle inserts from going up towards described firing chamber of cylinder head, with respect to cylinder-bore axis, to described spark plug slightly opposition side tilt and leave and dispose the front end nozzle from the central shaft adipping of described chamber.

Because Fuelinjection nozzle tilts to omiting opposition side with spark plug with respect to cylinder-bore axis, so, even the front end nozzle of the Fuelinjection nozzle central shaft from chamber is left, also can be to the central-injection fuel of chamber, replace, the central shaft of the chamber that makes the head-end ignition portion of spark plug avoid the jet flow of fuel and leave near the front end nozzle that makes Fuelinjection nozzle can carry out the igniting in mixing gas-bearing formation reliably.

In addition, since Fuelinjection nozzle with respect to cylinder-bore axis to spark plug slightly opposition side tilt, so the jet flow of coming out from Fuelinjection nozzle is accepted and is flow near the head-end ignition portion side of the spark plug the central shaft of chamber obliquely by chamber, thereby ignitability is good, has improved ignition effectiveness.

Though spark plug tilts with respect to cylinder-bore axis,,, can expect to improve fuel efficiency so do not need to strengthen chamber self owing to can make the central shaft of head-end ignition portion near chamber.

The present invention's 2 in-cylinder injection fuel oil type internal-combustion engine is that it is characterized in that: described Fuelinjection nozzle is the pneumatic type injection valve with bar-shaped injection mixed gas in the present invention's 1 in-cylinder injection fuel oil type internal-combustion engine; The chamber of the top end of described piston forms the longitudinal wall face around; Make the head-end ignition portion of described spark plug be positioned at the chamber of the described piston of upper dead center.

Because Fuelinjection nozzle is the pneumatic type injection valve that sprays mixed gas bar-shapedly, so avoid bar-shaped jet flow, make the central shaft of the head-end ignition portion of spark plug near chamber, can be located at easily in the chamber of piston of upper dead center.

Owing to around chamber, form the longitudinal wall face,, reach the combustion expense and reduce so, also can easily in chamber, form and mix gas-bearing formation even Fuelinjection nozzle tilts, jet flow is oblique enters.

The present invention's 3 in-cylinder injection fuel oil type internal-combustion engine, be in the present invention's 2 in-cylinder injection fuel oil type internal-combustion engine, it is characterized in that: described Fuelinjection nozzle, with in the compression stroke of being undertaken by described piston, its injection direction tilts towards the mode at the center of described chamber.

For in the compression stroke of being undertaken by piston, injection direction makes Fuelinjection nozzle tilt to the center of chamber, thus, injected mixed gas is taken in the chamber, can suppress to spread the rarefaction of the mixed gas that brings, and can light a fire reliably.

Description of drawings

Fig. 1 is the sectional arrangement drawing as the in-cylinder injection fuel oil type internal-combustion engine of one embodiment of the invention.

Fig. 2 is in the in-cylinder injection fuel oil type internal-combustion engine of Fig. 1, sectional drawing when piston is in upper dead center, that cut open along other line.

Fig. 3 is the view of the III-III direction of arrow of Fig. 1 of cylinder head.

Fig. 4 be with the fuel injection timing of compression stroke in, with the sectional drawing of the major component of the in-cylinder injection fuel oil type internal-combustion engine of the identical section of Fig. 2.

Fig. 5 be with the extruding that generates compression stroke the time interim, with the sectional drawing of the major component of the in-cylinder injection fuel oil type internal-combustion engine of the identical section of Fig. 2.

Among the figure: 1-crankcase, 2-cylinder, 3-cylinder head, 4-valve mechanism cover, the 5-piston, 6-connecting rod, 7-crankshaft, 8-firing chamber, the 9-Aspirating valves, 10-outlet valve, 11-camshaft, 12-back shaft, 13-exhaust cam driven member, 14-pitman arm shaft, 15, the 16-rocking arm, the 17-bar, the 20-squish area, 30-end face, 30a-subtend portion, 31-intakeport, 33, the 40-admission extinguisher, 41,42, the 43-Sealing, 44-air chamber, 45-fuel chambers, the 50-top end, 51-chamber, 51a-opening, 52-wall, the 53-peripheral portion, 53a-inner circumference edge, 60-Fuelinjection nozzle, 61-the 1st injection valve, 62-the 2nd injection valve, 62a-nozzle portion, 63-jet flow, the 63a-outer periphery, 70-spark plug, 71-igniting portion, the E-internal-combustion engine, L1-cylinder-bore axis, the central axis of L2-Fuelinjection nozzle, the central axis of L3-spark plug, V-driving valve device, Pa-air pump.

Embodiment

Below, describe based on Fig. 1 to Fig. 5 with regard to one embodiment of the invention.

With reference to Fig. 1, Fig. 2, use in-cylinder injection fuel oil type internal-combustion engine E of the present invention, be spark ignition type 4 stroke single cylinder internal combustion engines, has the cylinder 2 that is combined on the crank box 1 that can support crankshaft 7 rotatably, with the cylinder head 3 of the upper end that is combined in cylinder 2 be combined in the valve mechanism cover 4 of the upper end of cylinder head 3.

But be entrenched in to reciprocating action the piston 5 among the cylinder-bore 2a of cylinder 2, drive crankshafts 7 by connecting rod 6 rotations.

And internal-combustion engine E is positioned at the cylinder 2 in the place ahead of vehicle as shown in Figure 1 with respect to crankshaft 7, carries on two-wheeled with the state that tilts to the top of vehicle slightly.

Be between cylinder 2 and the cylinder head 3, between piston 5 and cylinder head 3, be formed with also as the firing chamber 8 that produces the variable volume space of volume-variation by the to-and-fro motion of piston 5.

Thereby here, firing chamber 8 at cylinder head side, is limited by the end face 30 that is made of the lower wall surface of cylinder head 3, in piston side, is limited by the top end 50 of piston 5 and the wall 52 that is formed at the chamber 51 of this top end 50.

This in-cylinder injection fuel oil type internal-combustion engine E, its cylinder-bore axis L1 is big to consistent with the central axis of firing chamber 8 and chamber 51.

Together with reference to Fig. 3, on cylinder head 3, be formed with the suction port 31 that is communicated with firing chamber 8 by 1 couple of intakeport 31a and by 1 pair of exhaust port 32 that relief opening 32a is communicated with firing chamber 8 in end face 30 upper sheds in end face 30 upper sheds, in addition, open and close the 1 pair of Aspirating valves 9 of 1 couple of intakeport 31a and the outlet valve 10 of switching relief opening 32a respectively, be set at cylinder-bore axis L1 is the summit of the summary equilateral triangle at center, and then, Fuelinjection nozzle 60 and spark plug 70, above cylinder head 3, insert, be installed in slightly opposite location with respect to cylinder-bore axis L1 with the side.

Fuelinjection nozzle 60, with respect to also as the cylinder-bore axis L1 of the central axis of firing chamber 8 and chamber 51, axis L 2 and insertion above cylinder head 3 with the little angle of inclination about about 10 degree, between a side intakeport 31a and relief opening 32a, dispose the front end nozzle 62a of portion highlightedly to firing chamber 8, as shown in Figure 4, be the form of the jet flow 63 of spray centerline with the axis L of pointing in the chamber 51 2, from the 62a of nozzle portion burner oil.

The 62a of nozzle portion towards its front end, has the guide portion 62a1 of solid of rotation shape outstanding in firing chamber 8.And, when guide portion 62a1 is mobile downwards by the drive unit driving, the jet flow 63 of spraying from the spout that between the top of guide portion 62a1 and minor diameter 62b, forms, flow along guide portion 62a1, so, the result of the expansion of inhibition after the outflow of above-mentioned spout is that its extended corner is little, roughly is bar-shaped.

In addition, spark plug 70, with respect to cylinder-bore axis L1 with Fuelinjection nozzle 60 opposition side roughly, have the axis L 3 at the angle of inclination about about 40 degree and insert from the side of cylinder head 3, between the opposing party's intakeport 31a and relief opening 32a, by interelectrode discharge, in firing chamber 8, to disposing the head-end ignition portion 71 that part takes place as spark near the cylinder-bore axis L1 highlightedly, as shown in Figure 2, the head-end ignition portion 71 of spark plug 70, when piston 5 is positioned at upper dead center, enter in the chamber 51 of the top end 50 that is formed at piston 5.

Once more, with reference to Fig. 1, Fig. 2, synchronously open and close the driving valve device V of Aspirating valves 9 and outlet valve 10 with the rotation of crankshaft 7, have: rotatably be supported on the footpath direction cylinder 2 sidepiece and have air inlet cam 11a and the camshaft 11 of exhaust cam 11b, with can joltily be supported on 1 pair of back shaft 12 being fixed on the cylinder 2 (back shaft of expression exhaust cam driven member 13 in Figure 12) respectively and go up and air inlet cam driven member that contacts with air inlet cam 11a and the exhaust cam driven member 13 that contacts with exhaust cam 11b, with air-breathing rocking arm 15 that can joltily be supported on respectively on the 1 pair of pitman arm shaft 14 that is fixed on the cylinder head 3 and be abutted against with the front end of the valve rod of 1 pair of Aspirating valves 9 and the exhaust rocker arm 16 that is abutted against with the front end of the valve rod of outlet valve 10, with 1 pair of bar 17, this bar 17, on above-mentioned air inlet cam driven member and exhaust cam driven member 13 and air-breathing rocking arm 15 and exhaust rocker arm 16, be abutted against at two end part respectively, the swing movement of this gas cam follower and exhaust cam driven member 13 is delivered to respectively on air-breathing rocking arm 15 and the exhaust rocker arm 16.

By comprising the driving mechanism of cam sprocket wheel 18 and timing chain 19,, rotate drive cam shaft 11 with its rotational speed of 1/2 by the power of crankshaft 7.And, air inlet cam 11a and exhaust cam 11b with camshaft 11 rotations, above-mentioned air inlet cam driven member and exhaust cam driven member 13 are shaken, this air inlet cam driven member and the exhaust cam driven member 13 that shake, by 1 pair of bar 17 air-breathing rocking arm 15 and exhaust rocker arm 16 are shaken, air-breathing rocking arm 15 that shakes and exhaust rocker arm 16 make to force in the 1 pair of Aspirating valves 9 of cut-off valve direction and outlet valve 10 by valve spring and synchronously open and close in prescribed period of time with the rotation of crankshaft 7 respectively.

Being formed at the chamber 51 of the top end 50 of piston 5, is to serve as the columned recess of central axis slightly with cylinder-bore axis L1, and facing the wall and meditating of being made of the 52b that faces the wall and meditates in underside wall 52a and week 52 limits.

Underside wall 52a, be the plane of inclination, gradually deepen at the end to head-end ignition portion 71 places with spark plug 70 from the front end nozzle 62a of portion with Fuelinjection nozzle 60, the mixed gas that sprays from the 62a of nozzle portion flows to the head-end ignition portion 71 of spark plug 70 easily and is stranded in this easily.

On the top end 50 of piston 5, has conical surface, this conical surface, and the end face 30 of cylinder head 3 between, be formed in the opening 51a outside, the squish area in the form of a ring 20 (with reference to Fig. 5) of chamber 51, wherein, cylinder head 3, here with on roughly certain footpath direction, have width and be roughly circular peripheral portion 53 relative to.

By relative with the conical surface of these piston 5 sides to the squish area that forms of the conical surface of cylinder head 3 sides 20 self, be formed from periphery to cylinder-bore axis L1, being the coniform of axis to the cylinder-bore axis L1 that tilts a little upward, by this cone shape squish area 20, generate from the firing chamber the inclination extruding (among Fig. 5, representing) of 8 peripheral portion with thick-line arrow to the center.

That is, in later half, the process of piston 5 near upper dead center of compression stroke, as shown in Figure 5, the air of the squish area 20 of coniform earth tilt is extruded towards cylinder-bore axis L1 obliquely along with narrowed width up and down, forms tiltedly extruding.

And this tiltedly pushes, become along the air-flow of the 30a of subtend portion, the 30a of this subtend portion, be on end face 30 and with upward to opening 51a relative to part.

With reference to Fig. 2, a part is installed on the cylinder head 3, remaining part is installed in the Fuelinjection nozzle 60 on the valve mechanism cover 4, is the mixed gas injection valve of the pneumatic type that the mixed gas that will be formed by fuel and high-pressure air acts as a fuel, the chamber in firing chamber 8 51 sprays.

And, Fuelinjection nozzle 60, with the injection timing of the regulation set according to the internal combustion engine operation state of the load of internal-combustion engine E and rotational speed, suction air quantity etc. and the fuel quantity of regulation, mixed gas is ejected in the firing chamber 8, and controls by not shown electric control device.

Wherein, injection timing, the no-load running of internal-combustion engine E zone or low in the load running zone, be set to the prescribed period of time in the compression stroke that should be carried out to the grate firing burning, in the high loaded process zone of internal-combustion engine E, be set to the prescribed period of time in the suction stroke that should spare the matter burning.

Fuelinjection nozzle 60 is made of the 1st injection valve 61 and the 2nd injection valve 62, and wherein, the 1st injection valve 61 is incorporated in the 1st admission extinguisher 40 that is formed on the valve mechanism cover 4 and burner oil only; The 2nd injection valve 62, its major part is incorporated in the 2nd admission extinguisher 33 that is formed on the cylinder head 3, the fuel that will spray from the 1st injection valve 61 and the mixed gas of high-pressure air, from the 62a of nozzle portion, spray with the form with jet flow 63 of pointing to central axis (spray centerline) L2 in the chamber 51.

The 2nd injection valve 62, the air introduction part 62c of end formed thereon is incorporated in the 1st admission extinguisher 40, and remaining part is incorporated in the 2nd admission extinguisher 33.And, be formed at the 62a of nozzle portion of the front end of the minor diameter 62b in the through hole that is inserted into cylinder head 3, in the face of in the firing chamber 8.

The 1st injection valve 61, its central axis is coaxial with the 2nd injection valve 62 with axis L 2, and conjointly disposes the 61a of nozzle portion with air introduction part 62c.

The 1st admission extinguisher 40, and the 61a of nozzle portion of the air introduction part 62c of the 2nd injection valve 62 and the 1st injection valve 61 between, surround the 1st, the 2nd injection valve 61,62 and form air chamber 44 by the airtight ring-type of the Sealing 41,42 of 1 pair of tubulose, and then, top in abutting connection with air chamber 44, between the 1st admission extinguisher 40 and the 1st injection valve 61, surround the 1st, the 2nd injection valve 61,62 and form firing chamber 45 by the airtight ring-type of the Sealing 43 of Sealing 42 and ring-type.

With reference to Fig. 1, Fig. 2, in air chamber 44, supply with high-pressure air, this high-pressure air by the power-actuated air pump Pa compression by the crankshaft 7 that transmits from cam 11, is set at the certain pressure of the defined higher than atmospheric pressure by pressure regulation device.In addition, supply with fuel under high pressure to fuel chambers 45, this fuel under high pressure by DYN dynamic petrolift (not shown) force feed, is set at the certain pressure of the defined of high pressure by pressure regulation device.

Such Fuelinjection nozzle 60, is installed on cylinder head 3 and the valve mechanism cover 4 with the angle of inclination about about 10 degree, and makes the front end nozzle 62a of portion outstanding to firing chamber 8 as the cylinder-bore axis L1 of the central axis of firing chamber 8 and chamber 51 with respect to also.

Thereby, even the front end nozzle 62a of portion of Fuelinjection nozzle 60 is left the central shaft (cylinder-bore axis L1) of chamber 51, as shown in Figure 4, also can be to the summary central-injection fuel of the chamber 51 of fuel injection timing, therefore, replacing the head-end ignition portion 71 be configured to make spark plug 70 avoids the jet flow 63 of mixed gas and near the structure of the central shaft (cylinder-bore axis L1) of the chamber 51 that the 62a of nozzle portion is left, can carry out the igniting (with reference to Fig. 5) in the mixing gas-bearing formation that is formed by chamber 51 reliably.

Spark plug 70, tilt approximately about 40 degree to omiting opposition side with respect to cylinder-bore axis L1 with Fuelinjection nozzle 60, but because can be with spark plug 70 self with the central shaft (cylinder-bore axis L1) of head-end ignition portion 71 near chamber 51, so do not interfere with spark plug 70, do not need to strengthen the opening 51a of chamber 51, therefore do not need to strengthen the capacity of chamber 51 yet, can expect to improve fuel efficiency.

With reference to Fig. 2, the guide portion 62a1 of the 62a of nozzle portion of the 2nd injection valve 62 and the igniting portion 71 of spark plug 70 when piston 5 is in upper dead center, does not interfere with piston 5 and are positioned at chamber 51.

And then, igniting portion 71 is at end face 30 and be positioned at below the guide portion 62a1 in the face of the 62a of nozzle portion of firing chamber 8 igniting portion 71, ignition timing when advance angle is configured to occupy the position of top slightly with the roughly the same height and position of opening 51a or inner circumference edge 53a or ratio open 51a.

Thereby, in the operation range of internal-combustion engine E, load running zone in the operation range high low as operating frequency, spark plug 70 carries out the igniting to mixed gas in igniting portion 71 is in chamber 51 time.

In addition, as shown in Figure 2, chamber 51 is present in the chamber 51 easily in order to make the mixed gas with the good proportions of ingredients of ignitability, with overlook with igniting portion 71 superposed part near deepen mode, constitute diapire face 52a by clinoplain.

And then, because central axis (spray centerline) L2 of Fuelinjection nozzle 60, tilt with respect to cylinder-bore axis L1, so from the direction of the jet flow 63 of the 62a of nozzle portion ejection, tilt more with respect to diapire face 52a, therefore, run into the reflected flux behind the diapire face 52a, have, around igniting portion 71, be more prone to centrostigma bad temper good mixing gas towards the velocity component of igniting portion 71.

Below, with reference to Fig. 4,5, describe for the mixed gas that sprays from Fuelinjection nozzle 60 and the relation of tiltedly extruding in the operation range that is carried out to the grate firing burning.

With reference to Fig. 4, Fuelinjection nozzle 60, from later stage of preceding half of compression stroke to the period that belongs to later half early stage, from the 62a of nozzle portion, in chamber 51, spray mixed gas along central axis (spray centerline) L2.

At this moment, mixed gas expands the little bar-shaped outer periphery 63a of angle of release towards the summary center of the diapire face 52a of chamber 51, and injected in the mode in the opening 51a that is retracted to chamber 51, mixed gas is not run into peripheral portion 53.

In addition, be positioned at the chamber 51 of the piston 5 of upper dead center according to the guide portion 62a1 that makes the 62a of nozzle portion, chamber 51 situation outward that is located at the piston 5 of upper dead center with guide portion 62a1 compares, guide portion 62a1 at injection timing, occupy more position near chamber 51, so the expansion at the mixed gas of the front end of jet flow 63 can become littler, can suppress the rarefaction of the mixed gas that brings by diffusion.

In addition, because chamber 51 forms peripheral wall surfaces 52b as longitudinal wall around, so, in chamber 51, also be detained easily and be difficult to spread mixed gas even Fuelinjection nozzle 60 tilts, makes jet flow 63 oblique entering.

With reference to Fig. 5, thereafter, along with piston 5 near upper dead center, as mentioned above, generation is 20 that form by squish area, towards cylinder-bore axis L1 oblique extruding upward, so, this tiltedly extruding suppress mixed gas (among the figure, the shape of being represented its summary by the crossing section line) foreign side from chamber 51 interior radius vector directions spreads, and then suppresses the mixed gas radius vector directions diffusion outside the chamber 51.

And, since tiltedly extruding for along the flowing of the 30a of subtend portion of end face 30, so be outside the chamber 51, above it, be present in cylinder-bore axis L1 around mixed gas is blocked by oblique extruding hardly.

Thereafter, it is preceding to reach upper dead center (with reference to Fig. 2) at piston 5, and the mixed gas of being lighted a fire by spark plug 70 takes fire.

On the position of prefiring piston 5, can prevent or suppress the diffusion of mixed gas and block by oblique extruding, so be the state that roughly closes in the chamber.

And, except be present at ignitability good mixing gas igniting portion 71 around, igniting portion 71 is also below than the guide portion 62a1 of the 62a of nozzle portion in the chamber 51 of the piston 5 that is located at upper dead center and be in position near the central axis (cylinder-bore axis L1) of chamber 51, at ignition timing, near the position of chamber 51, thus, the diffusion of mixed gas is smaller more, can carry out igniting, so can light a fire reliably in the part that is difficult to uncommon thinning.

By guaranteeing good ignitability, can prevent the mixed gas unburned and be discharged from, on the basis of improving fuel efficiency and toxic emission rate, can stride with chamber 51 be the center firing chamber 8 periphery full week, form thick air layer, reduce the cooling heat loss, improve the thermal efficiency and improve fuel efficiency.

In addition, at upper dead center, owing on the peripheral portion 53 that comprises squish area 20, have waste gas hardly, so can avoid the generation of detonation.

Further, owing to there is no need wall 52 that diffusion for the footpath direction that prevents and be suppressed at the mixed gas that comes out from chamber 51 makes chamber 51 up and down direction increase, so can carry out well on the basis of propagation of flame, also can reduce the volume of chamber 51 by the configuration structure of above-mentioned spark plug 70, can improve compression ratio by this volume reducing, the thermal efficiency can be improved, also fuel efficiency can be improved in this respect.

In the above-described embodiments, Fuelinjection nozzle 60 is mixed gas injection valves, from Fuelinjection nozzle 60 burner oils and Air mixing gas, but also can be from a Fuelinjection nozzle burner oil as jet flow.

In addition, the jet flow that is made of mixed gas or only by the jet flow of fuel mix also can be sprayed from the spout of the front end that is arranged on nozzle portion.

And then the 1st injection valve 61 makes central shaft with respect to the 2nd injection valve 62 differences, for example, also can be for identical with cylinder-bore axis L1 parallel or vertical, the structure that both are communicated with by air introduction part 62c.

Internal-combustion engine also can be a multi-cylinder internal-combustion engine.In addition, internal-combustion engine also can be equipped on the vehicle except that two-wheeled, and then except that vehicle, also can be the in-cylinder injection fuel oil type internal-combustion engine that is used on machine outside and other the machine.

Claims (3)

1. in-cylinder injection fuel oil type internal-combustion engine is characterized in that:

Be that top end forms between the piston and cylinder head of chamber, in the firing chamber that the lower wall surface with described cylinder head forms as end face, Fuelinjection nozzle and spark plug with a plurality of suction air valves in the face of combustion chamber configuration,

Described spark plug inserts to described firing chamber from the side of cylinder head, and tilt with respect to cylinder-bore axis and also dispose head-end ignition portion near the central shaft of described chamber,

Described Fuelinjection nozzle inserts from going up towards described firing chamber of cylinder head, with respect to cylinder-bore axis, to described spark plug slightly opposition side tilt and leave and dispose the front end nozzle from the central shaft adipping of described chamber.

2. according to the described in-cylinder injection fuel oil type of claim 1 internal-combustion engine, it is characterized in that: described Fuelinjection nozzle is the pneumatic type injection valve with bar-shaped injection mixed gas,

The chamber of the top end of described piston forms the longitudinal wall face around,

Make the head-end ignition portion of described spark plug be positioned at the chamber of the described piston of upper dead center.

3. according to the described in-cylinder injection fuel oil type of claim 2 internal-combustion engine, it is characterized in that: described Fuelinjection nozzle, with in the compression stroke of being undertaken by described piston, its injection direction tilts towards the mode at the center of described chamber.