CN1213221C - Air-suction device of engine - Google Patents

Abstract

The invention provides an air-suction device of engine. To form a more powerful swirl stream in a combustion chamber in an intake device for an engine in which a valve seat arranged at an inner end in an intake port generating swirl in the combustion chamber is fixed to a cylinder head at a position deviated from the center of the combustion chamber and a stem of an intake valve is slidably fitted into a guide cylinder provided in the cylinder head coaxially with the center of the valve seat. The intake port 70 on a projection drawing for a plane crossing an axial line of a cylinder bore orthogonally is formed into such shape that has a first passage part 70a extending in the direction of tangent of the guide cylinder 98 on an outer side more than the guide cylinder 98 and a second passage part 70b continuous with the first passage part 70a and curved and tapered so as to wind a part of the guide cylinder 98. An opposing wall 39a covering an umbrella part of the intake valve and the valve seat 97 except a part where it is overlapped on the first and second passage parts 70a, 70b on the projection drawing is provided in the cylinder head 39 by opposing to a part of the umbrella part and the valve seat 97.

Description

The suction means of motor

Technical field

The present invention relates to the suction means of motor, be particularly related to the improvement of engine air-suction apparatus, in this device, piston is engaged in the cylinder-bore slidably, the firing chamber faces the top of this piston, on cylinder head, be provided with and make the intakeport that produces vortex in this firing chamber, be configured in the ring-type valve seat of this intakeport the inner, position at center, bias combustion chamber is installed on the cylinder head, has the valve rod of Aspirating valves of can seat going into the umbrella portion of this valve seat, be engaged in slidably in the guide, this guide and valve seat center are located on the cylinder head coaxially.

Background technique

This suction means of the prior art, the pattern that for example has Japanese kokai publication hei 4-17707 communique to disclose.Be provided with spiral helicine intakeport on cylinder head, the inner of this intakeport communicates with the circular air-breathing valve port that valve seat forms.

In the above-mentioned conventional device, umbrella portion back side at Aspirating valves, in the inner end of intakeport, formation is around the cycle stream of Aspirating valves valve rod, the force of the suction mixed gas that produces at intakeport upstream side straight section, the rotating force that is used for minor radius around the above-mentioned valve rod reduces the flow velocity that flows into the mixed gas of firing chamber from intakeport greatly.In addition, when valve left by Aspirating valves, the mixed gas of in the umbrella portion back side cycle of Aspirating valves, flow into the firing chamber from the cylinder-bore axis direction, the cycle direction is different with the suction direction of firing chamber, so, be not easy to improve the mixed gas inspiratory flow rate of firing chamber, in the firing chamber, can not fully form vortex.

Summary of the invention

The present invention makes in view of the above problems, and its purpose is to provide a kind of engine air-suction apparatus that can form more powerful vortex flow in the firing chamber.

To achieve these goals, the suction means of the motor of the present invention program's 1 record, piston is engaged in the cylinder-bore slidably, the firing chamber faces the top of this piston, on cylinder head, be provided with and make the intakeport that produces vortex in the firing chamber, be configured in the ring-type valve seat of intakeport the inner, position at center, bias combustion chamber is installed on the cylinder head, has the valve rod of Aspirating valves of can seat going into the umbrella portion of this valve seat, be engaged in slidably in the guide, this guide and valve seat are located on the cylinder head coaxially, it is characterized in that, to with the projection drawing on the plane of the axis orthogonal of above-mentioned cylinder-bore on, above-mentioned intakeport forms the shape with the 1st passage portion and the 2nd passage portion; The 1st passage portion is extended at foreign side's side of guide tangent direction straight line shape along this guide, and, with the straight line orthogonal at the center of center that links the firing chamber and guide; The 2nd passage portion links to each other with the 1st passage portion, forms the curved shape that the part of guide is surrounded, and front end is narrow, and not with described projection drawing on straight line intersect; On above-mentioned projection drawing, except with the above-mentioned the 1st and the 2nd passage portion superposed part, cover the umbrella portion of Aspirating valves and the wall in opposite directions of valve seat, relatively be located on the cylinder head with the part of above-mentioned umbrella portion and valve seat.

According to this structure, with the plane figure of cylinder-bore axis orthogonal on, intakeport forms the shape with the 1st passage portion and the 2nd passage portion, the 1st passage portion is along the tangent direction of guide, the 2nd passage portion is crooked around the part of guide, front end is narrow.On above-mentioned projection drawing, except with the intakeport superposed part, the umbrella portion of Aspirating valves and valve seat are covered by wall in opposite directions, so, lead next mixed gas by intakeport, around being drawn into partially in the firing chamber of the periphery of the valve rod that Aspirating valves had, like this, in intakeport, do not make the mixed gas cycle, so, can avoid flow velocity to reduce, mixed gas is flowed in the firing chamber, can in the firing chamber, form powerful vortex.And, as long as intakeport is become the shape that the mixed gas unobstructed flow is crossed, just can reduce the passage resistance in the intakeport.

The invention of the present invention program's 2 records is in the suction means of the motor that such scheme 1 is put down in writing, and it is characterized in that, on above-mentioned projection drawing, the shape of the 2nd passage portion, forming and avoiding the shape of intersecting with straight line, this straight line is the straight line that links the center of the center of firing chamber and guide.According to this structure, can prevent with the firing chamber in the vortex flow direction in opposite directions that generates, produce the air-flow that flows into the mixed gas of firing chamber from intakeport, can further strengthen the vortex in the firing chamber.

The invention of the present invention program's 3 records, be in the suction means of such scheme 1 or 2 motors of putting down in writing, it is characterized in that, with the wall portion of the tube portion visible outline inner face of the corresponding part of crooked side tube part visible outline of the 2nd passage portion, by with the above-mentioned orthogonal of wall in opposite directions the longitudinal wall that is located on the cylinder head form.

According to this structure, can stipulate exactly that mixed gas sucks the scope of firing chamber, intakeport is tilted, reduce and plane (this flat sided straight meets at cylinder-bore axis) angulation, can further strengthen the vortex flow in the firing chamber.

Description of drawings

Fig. 1 is the profile of motor bike.

Fig. 2 is the sectional view along the power unit of 2-2 line among Fig. 1.

Fig. 3 is that the 3-3 alignment is looked enlarged view among Fig. 2.

Fig. 4 is a 4-4 line amplification profile diagram among Fig. 2.

Fig. 5 is the 5-5 line sectional view of Fig. 4.

Fig. 6 is that 6 among Fig. 5 is to view.

Fig. 7 be towards with the projection drawing of the intakeport on the plane of cylinder-bore axis orthogonal.

Fig. 8 is the 8-8 line sectional view of Fig. 5.

Embodiment

Below, with reference to one embodiment of the invention shown in the accompanying drawing, example of the present invention is described.

Fig. 1 to Fig. 8 represents one embodiment of the invention.Fig. 1 is the profile of motor bike.Fig. 2 is the sectional view along the power unit of 2-2 line among Fig. 1.Fig. 3 is that the 3-3 alignment is looked enlarged view among Fig. 2.Fig. 4 is a 4-4 line amplification profile diagram among Fig. 2.Fig. 5 is the 5-5 line sectional view of Fig. 4.Fig. 6 is that 6 among Fig. 5 is to view.Fig. 7 be towards with the projection drawing of the intakeport on the plane of cylinder-bore axis orthogonal.Fig. 8 is the 8-8 line sectional view of Fig. 5.

As shown in Figure 1, the front end of the vehicle frame 15 of motor bike has head pipe 16, and the front fork 17 of an axle front-wheel WF can turn to the ground pivot to prop up on this pipe 16.Connecting handlebar stem 18 in the upper end of this front fork 17, the front mudguard 19 that covers front-wheel WF top is bearing on the front fork 17.At the intermediate portion of vehicle frame 15, pivot is propping up the back vent 20 of an axle trailing wheel WR, between the rear portion and back vent 20 of vehicle frame 15, is provided with posterior bumper 21.

At the intermediate portion of vehicle frame 15, supporting the power unit P that constitutes by water-cooled spark-ignition four-stroke engine E and variable-speed motor M, the output of above-mentioned variable-speed motor M is delivered to trailing wheel WR by loop chain 22.

Be configured in the air-strainer 23 and the radiator 24 of motor E top, be bearing on the vehicle frame 15, be configured in variable-speed motor M top fuel tank 25, accommodate electric product and be configured in these fuel tank 25 tops accommodate case 26, be bearing on the vehicle frame 15.

Guiding is from the outlet pipe 27 of motor E exhaust, and is configured in power unit P and is connected with muffler 28 between trailing wheel WR.

The front portion of vehicle frame 15, motor E, air-strainer 23 and radiator 24 are covered with by the synthetic resin system legging cover 29 that is installed on the vehicle frame 15.The rear portion of vehicle frame 15, fuel tank 25 and accommodate case 26 are covered with by the synthetic resin system back cover 30 that is installed on the vehicle frame 15, on this back cover 30, are being connected with the rear mudguard 31 that covers top, trailing wheel WR rear portion.On back cover 30, be provided with and can open and close the vehicle seat 32 of accommodating case 26 upper end open portions, the driver can be sitting on this vehicle seat 32.

In the place ahead that is sitting in the driver on the vehicle seat 32, disposing windshield 33 with transmission of light, this windshield 33 is installed on the handle cover 34 that covers handlebar stem 18.

Among Fig. 2 to Fig. 5, the engine body 37 of motor E is made of cylinder block 38, cylinder head 39 and crank box 40.Cylinder block 38 has cylinder-bore 44, and piston 43 is engaged in this cylinder-bore 44 slidably.Cylinder head 39 is combined on the cylinder block 38, and the top of piston 43 between form firing chamber 45.Crank box 40 is combined on the cylinder block 38, rotatably mounted crankshaft 47, and this crankshaft 47 links by connecting rod 46 and piston 43.Cylinder block 38, cylinder head 39 and crank box 40 are with several, for example 4 bolt 41... connect.In addition, crank box 40 is mutually combined as matching surface on interior plane and constitutes with the rotation axis of doing that comprises piston 43 by right crank box halfbody 40a and left crank box halfbody 40b.In crank box 40, form crank chamber 42.Engine body 37 is configured in the front portion with the cylinder head 39 that is configured in the tight back of front-wheel WF, and engine body 37 is bearing on the vehicle frame 15 so that the axis of cylinder-bore 44 is the posture of the about level of cylinder-bore axis.

Variable-speed motor M have main shaft 51, countershaft 52 and be located at main shaft 51 and countershaft 52 between some grades of gear trains 53.Main shaft 51 and countershaft 52 have the axis parallel with crankshaft 47, and be rotatably mounted by crank box 40.Some grades of gear trains 53 are selectively established.On crank box 40, rotatably support displacement tube 54, and this displacement tube 54 is used for selectively establishing said gear group 53.

End from the outstanding crankshaft 47 of right crank box halfbody 40a, be connected with actuation gear 56 by centrifugal clutch 55, with the driven gear 57 that this actuation gear 56 is meshing, can be bearing in distolateral from the outstanding main shaft 51 of right crank box halfbody 40a with the relative rotation.Driven gear 57 is connected with the clutch outside plate 60 of clutch 59 by damping rubber 58.This clutch 59 is multi-plate clutchs, by with the effect of the corresponding release cam of driver's operation mechanism 61, make the breaking and connecting of 60 of the clutch 62 that is combined on the main shaft 51 and above-mentioned clutch outside plates.At the state of this clutch 59 of blocking-up, selectively establish said gear group 53.Above-mentioned clutch 55 and clutch 59 are covered with by the right side cover 63 that is combined on the right crank box halfbody 40a.

In end, fixing driving sprocket wheel 64, the chain 22 of reeling on this driving sprocket wheel 64 from the outstanding countershaft 52 of left crank box halfbody 40b.Pass through chain 22 to trailing wheel WR transferring power from this driving sprocket wheel 64.

In the other end from the outstanding crankshaft 47 of left crank box halfbody 40b, fixing the rotor 66 of generator 65, left side cover 68 covers these generator 65 ground and is combined on the left crank box halfbody 40b, and the stator 67 of generator 65 is fixed on this left side cover 68.

On the cylinder block 38 and cylinder head 39 of engine body 37, be provided with the water jacket 48 that cooling water is flow through, on cylinder head 39, face 45 ground, firing chamber a pair of spark plug 49,50 is installed, the firing time of this a pair of spark plug 49,50 is different.

Be provided with intakeport 70 from mixed gas to firing chamber 45 that supply with on cylinder head 39, this intakeport 70 is at the top of cylinder head 39 upward opening.In addition, be provided with relief opening 71 on cylinder head 39, this relief opening 71 is used to discharge the exhaust of coming out in firing chamber 45, at the bottom of cylinder head 39 downwardly facing opening.At above-mentioned intakeport 70, the Carburetor that does not show by figure is connecting air-strainer 23, at above-mentioned relief opening 71, is connecting outlet pipe 27.

The outlet valve 75 that switches the Aspirating valves 74 of intakeport 70 and the switching of 45 of firing chambers and switch relief opening 71 and the switching of 45 of firing chambers, but on-off action be provided on the cylinder head 39, Aspirating valves 74 and outlet valve 75 quilts push towards closing the valve direction.

Above-mentioned Aspirating valves 74 and outlet valve 75 are by valve mechanism 76 driven opening.This valve mechanism 76 is housed in the valve cage 79, and this valve cage 79 is formed between cylinder head 39 and the valve mechanism cover 78 (the some bolt 77... of these valve mechanism cover 78 usefulness are combined on the cylinder head 39).

Above-mentioned valve mechanism 76 has camshaft 80, suction side and exhaust side pitman arm shaft 83,84, suction side rocking arm 85, exhaust side rocking arm 86.Camshaft 80 has the axis parallel with crankshaft 47, can be rotated to support on the cylinder head 39, and is provided with suction side and exhaust side cams 81,82.Suction side and exhaust side pitman arm shaft 83,84 have the axis parallel with camshaft 80, are bearing on the cylinder head 39.Suction side rocking arm 85 is driven in suction side cam 81, is being supported swingably by the suction side pitman arm shaft 83 of driven opening Aspirating valves 74.Exhaust side rocking arm 86 is driven in exhaust side cams 82, is being supported swingably by the exhaust side pitman arm shaft 84 of driven opening outlet valve 75.

As shown in Figure 2, between the left crank box halfbody 40b and generator 65 of crank box 40, on crankshaft 47, fixing driving sprocket wheel 87, in the part corresponding with this driving sprocket wheel 87, crank chamber 42 in the connecting crank case 40 and the chain path 88 between the valve cage 79 are located between left crank box halfbody 40b, cylinder block 38 and the cylinder head 39.

In the part corresponding with above-mentioned chain path 88, in the end of camshaft 80, fixing by movable sprocket 89, this by movable sprocket 89 and driving sprocket wheel 87 on, the endless chain 90 of reeling and can in chain path 88, walk.

At above-mentioned driving sprocket wheel 87 and between by movable sprocket 89, chain 90 is wound on the idler sprockets 91 (this idler sprockets 91 is bearing on the cylinder block 38), between this idler sprockets 91 and driving sprocket wheel 87,, give tension force to chain 90 by the stretcher 92 that is provided on the left crank box halfbody 40b.

Water pump 93 is installed on cylinder head 39, and this water pump 93 has the spin axis coaxial with the camshaft 80 of valve mechanism 76.On the pump case 94 of this water pump 93, be provided with thermostat 95, the action of this thermostat 95 is, cold state at motor E, make the cooling water of water jacket 48 return water jacket 48 through thermostat 95 and water pump 93, at the warming-up of the motor state that is over, make cooling water that water jacket 48 comes out through radiator 24, thermostat 95 and water pump 93, return water jacket 48.

As shown in Figure 5, the position at 45 centers, bias combustion chamber on cylinder head 39, is setting firmly the ring-type valve seat 97 that is configured in intakeport 70 the inners with being pressed into mode etc.Aspirating valves 74 has can seat goes into the 74a of umbrella portion of valve seat 97 and coaxial and be connected with valve rod 74b into one with the 74a of this umbrella portion.This valve rod 74b is engaged in the guide 98 slidably, and this guide 98 is located on the cylinder head 39 coaxially with valve seat 97.Between the upper end portion and cylinder head 39 of the valve rod 74b that gives prominence to from guide 98, be provided with valve spring 99, these valve spring 99 performances make the 74a of umbrella portion seat go into the spring force of valve seat 97, in the upper end of valve rod 74b, are linking the suction side rocking arm 85 of valve mechanism 76 linkedly.

The inner of relief opening 71 is on a diameter line of firing chamber 45, between the inner that is centered close to relief opening 71 of firing chamber 45 and the inner of intakeport 70.Outlet valve 75 has the 75a of umbrella portion, this 75a of umbrella portion seat is gone into valve seat, and (figure does not show, this valve seat is positioned at the inner of relief opening 71 and is installed on the cylinder head 39), this outlet valve 75 and above-mentioned Aspirating valves 74 are similarly, but be bearing in guide (figure does not show on-off action, this guide is fixed on the cylinder head 39) on,, linked linkedly towards the outlet valve 75 that closes valve direction pushing by valve spring 100 (see figure 3)s with the exhaust side rocking arm 86 of valve mechanism 76.

Among Fig. 6, intakeport 70 is located on the cylinder head 39, and makes generation vortex in the firing chamber 45.The a pair of spark plug 49,50 that is installed on the cylinder head 39 is set like this: the vortex flow direction 101 along the firing chamber in 45 is high more away from the intakeport calorific value more.That is, along above-mentioned flow direction 101, be positioned at the calorific value of the spark plug 49 of intakeport 70 tight downstream sides, than low away from the calorific value of the spark plug 50 of intakeport 70 positions along above-mentioned flow direction 101.Among this embodiment,, be the upstream side of outlet valve 75 at relief opening 71 along above-mentioned flow direction 101, the low spark plug 49 of configuration calorific value; Along above-mentioned flow direction 101, be the downstream side of outlet valve 75 at relief opening 71, the high spark plug 50 of configuration calorific value.

And motor E carries on vehicle frame 15, and the axis of its cylinder-bore 44 is about level.Upper portion side wall in cylinder head 39 is disposing intakeport 70, so in firing chamber 45,45 the opening end towards the firing chamber that the spark plug 49 that calorific value is low is configured in intakeport 70 is the tight below of Aspirating valves 74.

Intakeport 70 has makes the shapes that produce vortexs in the firing chamber 45, with the projection drawing on the plane of the axis orthogonal of cylinder-bore 44 on, as shown in Figure 7, intakeport 70 has the 1st passage portion 70a and the 2nd passage portion 70b.The 1st passage portion 70a extends along the tangent direction of this guide 98 in foreign side's side of guide 98.The 2nd passage portion 70b links to each other with the 1st passage portion 70a, and crooked around the part of guide 98, front end narrows down.

The 1st passage portion 70a and straight line 102 (center C 1 of these straight line 102 binding firing chambers 45 and center C 2 of guide 98) orthogonal, and straight line shape ground extends along the tangent direction of guide 98.The 2nd passage portion 70b in order not intersect with straight line 102 on above-mentioned projection drawing, makes around the crooked shape of the part of guide 98 and be formed.

As shown in Figure 8, on cylinder head 39, except with the 1st and the 2nd passage portion 70a, the 70b superposed part of intakeport 70, cover the 74a of umbrella portion of Aspirating valves 74 and wall in opposite directions (part shown in Fig. 7 bend) 39a of valve seat 97, be provided with opposite to each other with the part of 74a of umbrella portion and valve seat 97.That is, be configured in the form of a ring on the part of valve seat 97 of intakeport 70 the inners, in fact play the effect of air-breathing valve port 103.Aspirating valves 74 drive valve the time, among the valve seat 97 except the part that covered by the above-mentioned 39a of wall in opposite directions, be that air-breathing valve port 103 is openings.

The inner side surface of the intakeport 70 of the part corresponding with the interior side's side visible outline that constitutes the 2nd passage portion 70b is by forming with wall 39a orthogonal ground in opposite directions, the longitudinal wall 39b (see figure 5) that is located on the cylinder head 39.

The following describes this embodiment's effect.With the projection drawing on the plane of the axis orthogonal of cylinder-bore 44 on, intakeport 70 forms the shape with the 1st passage portion 70a and the 2nd passage portion 70b.The 1st passage portion 70a extends along the tangent direction of this guide 98 in foreign side's side of the guide 98 of the on-off action of guiding Aspirating valves 74.The 2nd passage portion 70b links to each other with the 1st passage portion 70a, and crooked around the part of guide 98, front end narrows down.On above-mentioned projection drawing, except the 1st and the 2nd passage portion 70a, 70b superposed part, the 74a of umbrella portion of Aspirating valves 74 and valve seat 97 are covered by the 39a of wall in opposite directions of cylinder head 39.

Therefore, by the next mixed gas of intakeport 70 guidings, the part of the periphery of the valve rod 74b that is had around Aspirating valves 74, be inhaled in the firing chamber 45, mixed gas is circled round, so, can avoid flow velocity that mixed gas is flowed in the firing chamber 45, in firing chamber 45, can form powerful vortex.And intakeport 70 becomes the shape that the mixed gas unobstructed flow is crossed, so, can reduce the passage resistance in the intakeport 70.

On the above-mentioned projection drawing, front end at the 2nd passage portion 70b, form as the shape of the longitudinal wall 39b of wall and to avoid the shape of intersecting with straight line 102 (this straight line 102 is the straight lines that are connected the center C 2 of the center C 1 of firing chamber 45 and guide 98), so, with firing chamber 45 in the vortex flow direction in opposite directions that produces, can prevent to flow into the air-flow of the mixed gas of firing chamber 45 conscientiously, like this, make the vortex in the firing chamber 45 stronger from intakeport 70.

Inner side surface with the intakeport 70 of interior side's side visible outline counterpart of the 2nd path 70b, by forming with the longitudinal wall 39b that is located on the cylinder head 39 in opposite directions wall 39a orthogonal, so, the regulation mixed gas is drawn into the scope in the firing chamber 45 exactly, intakeport 70 is tilted, angle with the plane that is orthogonal to cylinder-bore axis is reduced, like this, can make the vortex flow in the firing chamber 45 stronger.

In order to reduce fuel cost and to improve exhaust performance, some, a pair of spark plug 49,50 for example is installed on cylinder head 39, this spark plug 49,50 faces firing chamber 45 and is installed with interiorly in the space of avoiding Aspirating valves 74 and outlet valve 75.The calorific value of these spark plugs 49,50 is different, the vortex flow direction 101 along the firing chamber in 45, and the calorific value near the spark plug 49 of intakeport 70 is lower than the calorific value away from the spark plug 50 of intakeport 70.

Promptly, along with the gasification of the mixed gas in the firing chamber 45 and the carrying out of diffusion, become the combustion gas of the burning generation of thinner mixed gas than higher temperatures, the calorific value of the spark plug 50 in this comparison high-temperature combustion gas is set than higher, and flow into the denseer mixed gas in firing chamber 45 from intakeport 70, the calorific value of the spark plug 49 that contacts with this denseer mixed gas and may cool off is set lowlyer, like this, can prevent that spark plug 49 from smoldering and cause misfire.

In addition, motor 37 carries on vehicle frame 15, its cylinder-bore axis is about level, above the minimum spark plug 49 of calorific value, on cylinder head 39, be provided with the intakeport 70 of 45 inner openings towards the firing chamber, so, even fuel does not flow in the firing chamber 45 along the lower inner face of intakeport 70 with not atomizing, the calorific value of the spark plug 49 that can contact with this fuel, it is the lowest among each spark plug 49,50, so, can avoid contacting and producing smoldering with atomized fuel not, can prevent because of spark plug 49 misfire of smoldering.

Embodiments of the invention have been described above, but the present invention is not limited to the foregoing description.In the claim scope, can do various design alterations.

As mentioned above,, avoid flow velocity that mixed gas is flowed in the firing chamber, can in the firing chamber, form powerful vortex according to the invention of such scheme 1 record.And, can reduce the passage resistance in the intakeport.

According to the invention of such scheme 2 record, with the firing chamber in the vortex flow direction in opposite directions that produces, prevent to produce the mixed airflow that flows into the firing chamber from intakeport, can in the firing chamber, form more powerful vortex.

According to the invention of such scheme 3 records, intakeport is tilted, reduce and the plane angulation that is orthogonal to cylinder-bore axis, can more strengthen the vortex flow that in the firing chamber, forms.

Claims (2)

1. the suction means of a motor, piston (43) is engaged in the cylinder-bore (44) slidably, the firing chamber faces the top of this piston (43), on cylinder head (39), be provided with and make the intakeport (70) that produces vortex in the firing chamber (45), be configured in the inner ring-type valve seat (97) of intakeport (70), be installed on the cylinder head (39) in the position at center, bias combustion chamber (45), has the valve rod (74b) of Aspirating valves (74) of can seat going into the umbrella portion (74a) of this valve seat (97), be engaged in slidably in the guide (98), this guide (98) is located on the cylinder head (39) coaxially with valve seat (97), it is characterized in that, to with the projection drawing on the plane of the axis orthogonal of described cylinder-bore (44) on, described intakeport (70) forms the shape with the 1st passage portion (70a) and the 2nd passage portion (70b), described the 1st passage portion (70a) is extended at foreign side's side of guide (98) tangent direction straight line shape along this guide (98), and, with the center (C that links firing chamber (45) ₁) and the center (C of guide (98) ₂) straight line (102) orthogonal; Described the 2nd passage portion (70b) links to each other with the 1st passage portion (70a), forms the curved shape that the part of guide (98) is surrounded, and front end is narrow, and not with described projection drawing on straight line (102) intersect; On described projection drawing, except with the described the 1st and the 2nd passage portion (70a, 70b) superposed part, cover the umbrella portion (74a) of Aspirating valves (74) and the wall in opposite directions (39a) of valve seat (97), relatively be located on the cylinder head (39) with the part of described umbrella portion (74a) and valve seat (97).

2. the suction means of motor as claimed in claim 1, it is characterized in that, with the wall portion of the tube portion visible outline inner face of the corresponding part of crooked side tube part visible outline of the 2nd passage portion (70b), by with described wall in opposite directions (39a) orthogonal the longitudinal wall (39b) that is located on the cylinder head (39) form.

Images