CN103249923B - Gas-liquid separation device for four-stroke engine, and lubrication device for four-stroke engine - Google Patents

Abstract

The present invention provides a kind of gas-liquid separation device of the four-stroke engine of gas-liquid separation for more ensuring lubricating oil and gas blowby and the lubricating arrangement of four-stroke engine, so that lubricating oil will not be emitted into combustion chamber. Oil eliminator (51) of the invention have formed from oil circulation path branch, the gas-liquid separation chamber (117) for isolating mist of oil from the gas blowby containing mist of oil, gas-liquid separation chamber (117) includes the first opening portion (103), imports gas blowby from oil circulation path; Second opening portion (105), makes the lubricating oil isolated from gas blowby be back to oil circulation path; The gas blowby for being separated mist of oil is vented from gas-liquid separation chamber, and is connected to the inlet channel toward combustion chamber by third opening portion (501g). First opening portion (103) is formed in the first wall (101), third opening portion (501g) is formed in the second wall (501d), in gas-liquid separation chamber (117), gas-liquid separate component is formed between the first opening portion (103) and third opening portion (501g).

Description

The gas-liquid separation device of four stroke engine and the lubricating fitting of four stroke engine

Technical field

The present invention relates to a kind of for separating of the mist of oil of four stroke engine and the gas-liquid separation device of gas blowby, and the lubricating fitting of four stroke engine.

Background technique

Due to reasons such as the severizations that and exhaust surging to the consciousness of environmental problem specify, mowing machine and Backpack work machine, to carry as operating personnel oneself or to bear the driving motor carrying out the working machine of operation, being just replaced by four stroke engine gradually from two stroke engine.

This four stroke engine, needed for it, the quantity of parts is more than two stroke engine, and therefore four stroke engine easily becomes heavy, particularly portable working machine, due to be by operating personnel's carrying operation machine while carry out premised on operation, therefore, require its motor lightweight.

Therefore, develop to have and need not lubrication pump be set separately and the four stroke engine (with reference to patent documentation 1 and patent documentation 2) that utilizes the pressure in crankshaft room to change to make the lubricating fitting of lubrication oil circulation.This lubricating fitting has the safety check be arranged on bottom crankshaft room.This safety check is opened when malleation, and the lubricant oil in crankshaft room or mist of oil are transported in accumulator.The lubricant oil or the mist of oil that have passed the connecting tube be arranged in accumulator are supplied to gas distributing chamber and drive the air distributing device of this gas distributing chamber, and sufficient lubricant oil will be supplied to gas distributing chamber and air distributing device.When piston rises mobile, be arranged on the intercommunicating pore opening in crankshaft room, make crankshaft room and gas distributing chamber become connected state, thus make the oil return of alluvial in gas distributing chamber to crankshaft room.

But be mixed into gas blowby in the lubrication path of lubricant oil, under the state that the gas blowby concentration in lubrication path raises, if lubricant oil and gas blowby continue to mix, then lubricant oil will go bad further, produce harmful effect to the lubrication of driver part.Therefore, generally take the gas blowby in lubrication path to be disposed to firing chamber, thus the measure preventing lubricant oil from going bad in advance, also as described in Patent Document 1, often adopt the structure being communicated with gas distributing chamber and firing chamber by air cleaner.

prior art document

patent documentation

[patent documentation 1] Japanese Patent Laid-Open 08-260926 publication

[patent documentation 2] Japanese Patent Laid-Open 2007-224824 publication

Summary of the invention

the problem that invention will solve

Usually, around bent axle, need the lubricant oil of high concentration, and in air distributing device, do not need the lubricant oil of high concentration as around bent axle.

Existing lubricating fitting, the pressure in crankshaft room is utilized to change, the concentration of the lubricant oil in crankshaft room or mist of oil is not adjusted and is directly delivered to gas distributing chamber and air distributing device, therefore in order to lubricate air distributing device, excessive lubricant oil or mist of oil is had to send into gas distributing chamber, cause the lubricants capacity of alluvial in gas distributing chamber too much, also discharge lubricant oil in a large number while discharge gas blowby to firing chamber, thus there is the problem exhausting lubricant oil in advance.Therefore, the time of make-up oil shortens, if make-up oil not in time, will cause insufficient lubrication.In addition, if increased further the Grease relief amount of firing chamber, then lubricant oil will be disposed to outside from baffler in large quantities with unburned state, likely produce harmful effect to environment.

The present invention completes in view of above-mentioned background, its object is to provide a kind of in order to prevent Grease relief to firing chamber, thus more positively can carry out the gas-liquid separation device of four stroke engine and the lubricating fitting of four stroke engine of the gas-liquid separation of lubricant oil and gas blowby.

for the scheme of dealing with problems

For solving the problem; the invention provides a kind of gas-liquid separation device of four stroke engine; it is characterized in that; to have from oil circulation path branch formed, for from containing the gas-liquid separation chamber isolating mist of oil the gas blowby of mist of oil; above-mentioned gas-liquid separation chamber has: the first opening portion, and it imports above-mentioned gas blowby from above-mentioned oil circulation path; Second opening portion, it makes from the isolated oil return of above-mentioned gas blowby to above-mentioned oil circulation path; 3rd opening portion, the gas blowby being separated mist of oil is vented from above-mentioned gas-liquid separation chamber by it, and the gas-entered passageway be communicated to toward firing chamber, above-mentioned first opening portion is formed at first wall, above-mentioned 3rd opening portion is formed at the second wall, in above-mentioned gas-liquid separation chamber, between above-mentioned first opening portion and above-mentioned 3rd opening portion, be formed with gas-liquid separate component.

By above-mentioned constitutive requirements, particularly this gas-liquid separation device has gas-liquid separate component, thus can suitably isolate aqueous lubricant oil from gas blowby.

In addition, due to can suitably separation lubrication oil, thus the consumption of lubricant oil can be suppressed, and then suppress discharge environment being had to dysgenic unburned lubricant oil.

According to an aspect of the gas-liquid separation device of four stroke engine of the present invention, from inflow direction and the outflow direction of the gas blowby flowed out from above-mentioned 3rd opening portion of the gas blowby of above-mentioned first opening portion inflow, be formed as the position relationship reversed.

Owing to having such structure, gas-liquid separation device of the present invention can suitably isolate aqueous lubricant oil from gas blowby.

According to an aspect of the gas-liquid separation device of four stroke engine of the present invention, above-mentioned first opening portion is formed near the central authorities of above-mentioned first wall, and above-mentioned 3rd opening portion is formed in any position in the corner, left and right two of the upper side direction position of above-mentioned second wall.

Owing to having such structure, the gas-liquid separation device of four stroke engine of the present invention more suitably can carry out gas-liquid separation.

According to an aspect of gas-liquid separate component of the present invention, above-mentioned gas-liquid separate component is the pad near entreating wherein with multiple middle thereof hole.

Owing to having such structure, the gas-liquid separation device of four stroke engine of the present invention can be separated by the first pad the lubricant oil that in aqueous lubricant oil, oil droplet is large.

According to an aspect of gas-liquid separate component of the present invention, in any position in the corner, left and right two of position, above-mentioned second opening portion is formed with at the lower side of above-mentioned first wall, on above-mentioned first wall, to surround the mode of above-mentioned first opening portion, ditch portion is formed in the position, more lateral, ratio above-mentioned middle thereof hole of above-mentioned pad, form duct-like lubricant oil return passage by above-mentioned ditch portion and above-mentioned pad, above-mentioned lubricant oil return passage is communicated with above-mentioned second opening portion.

Owing to having such structure, the gas-liquid separation device of four stroke engine of the present invention can make the aqueous lubricant oil be separated in the first pad efficiently from the second opening portion discharge.

According to an aspect of gas-liquid separate component of the present invention, on the corner of above-mentioned pad, on the position being formed with above-mentioned second opening portion of above-mentioned first wall, be formed with through hole.

Owing to having such structure, the gas-liquid separation device of four stroke engine of the present invention can make the aqueous lubricant oil by being separated after the first pad, also can efficiently from the second opening portion discharge.

According to an aspect of gas-liquid separate component of the present invention, above-mentioned gas-liquid separate component is in upper side direction position and the corner location of the opposition side of above-mentioned 3rd opening portion formation side is formed with the pad of through hole.

Owing to having such structure, the gas-liquid separation device of four stroke engine of the present invention flows into gas-liquid separation chamber by the gas blowby containing aqueous lubricant oil by the first opening portion, and the gas blowby of inflow collides the second pad, thus separable aqueous lubricant oil.

In addition, the through hole of the second pad is formed on the position of the opposition side being formed with the 3rd opening portion side, therefore, it is possible to make to be discharged from the 3rd opening portion swimmingly by the gas blowby of this through hole.

According to an aspect of gas-liquid separate component of the present invention, in any position in the corner, left and right two of position, be formed with above-mentioned second opening portion at the lower side of above-mentioned first wall.

Owing to having such structure, the gas-liquid separation device of four stroke engine of the present invention more positively can discharge aqueous lubricant oil from the second opening portion.

According to an aspect of gas-liquid separate component of the present invention, above-mentioned second opening portion is formed at the Power Available Shaft side of four stroke engine in two corners, left and right, above-mentioned 3rd opening portion be formed in two corners, left and right with the opposition side of above-mentioned live axle.

Owing to having such structure, during by Power Available Shaft down, lubricant oil after gas-liquid separation more easily can get back to oil circulation path from the second opening portion, and by Power Available Shaft upward time, the through hole be formed on the position in contrary corner, above-mentioned 3rd opening portion formation side can become more upward, more suitably can isolate aqueous lubricant oil from gas blowby by this.

According to an aspect of gas-liquid separate component of the present invention, above-mentioned gas-liquid separate component has mesh shape.

Owing to having such structure, the gas-liquid separation device of four stroke engine of the present invention also can isolate the little mist of oil of oil droplet.

Above-mentioned first wall is formed as relative with above-mentioned second wall.

Owing to having such structure, can fully guarantee the space being formed with gas-liquid separate component.

According to an aspect of gas-liquid separate component of the present invention, its have there is multiple through hole near central authorities the first pad, in upper side direction position and above-mentioned 3rd opening portion form the corner of the opposition side of side position on be formed with the second pad of through hole, and the net of mesh shape, above-mentioned first pad, above-mentioned second pad and above-mentioned net, from above-mentioned first opening portion side, it is the arranged in order by above-mentioned first pad, above-mentioned net and above-mentioned second pad.

Owing to having such structure, by the complementary effect of the first pad, the second pad and above-mentioned net, more effectively mist of oil can be isolated.

According to an aspect of gas-liquid separate component of the present invention, it has first pad near central authorities with multiple through hole, and in upper side direction position and above-mentioned 3rd opening portion form the corner of the opposition side of side position on be formed with the second pad of through hole, above-mentioned first pad and above-mentioned second pad, from above-mentioned first opening portion side, it is the arranged in order by above-mentioned first pad, above-mentioned second pad.

Owing to having such structure, by the complementary effect of above-mentioned first pad and above-mentioned second pad, can more effectively isolate aqueous lubricant oil.

According to an aspect of gas-liquid separate component of the present invention, it has first pad near central authorities with multiple through hole, and the net of mesh shape, above-mentioned first pad and above-mentioned net, from above-mentioned first opening portion side, it is the arranged in order by above-mentioned first pad, above-mentioned net.

Owing to having such structure, by the complementary effect of above-mentioned first pad and above-mentioned net, can more effectively isolate aqueous lubricant oil.

According to an aspect of gas-liquid separate component of the present invention, it has in upper side direction position and the position in the corner of the opposition side of above-mentioned 3rd opening portion formation side is formed with the second pad of through hole, and the net of mesh shape, above-mentioned second pad and above-mentioned net, from above-mentioned first opening portion side, it is the arranged in order by above-mentioned net, above-mentioned second pad.

Owing to having such structure, by the complementary effect of above-mentioned second pad and above-mentioned net, can more effectively isolate aqueous lubricant oil.

According to an aspect of the lubricating fitting of four stroke engine of the present invention, pressure change in the crankshaft room that its utilization produces because of the to-and-fro motion of piston, lubricant oil is supplied to the part as above-mentioned oil circulation path and the above-mentioned crankshaft room formed and gas distributing chamber, thus lubricate, it is characterized in that, be provided with in above-mentioned crankshaft room as being communicated with the put-through channel of above-mentioned gas distributing chamber and above-mentioned crankshaft room during negative pressure, the open end to above-mentioned crankshaft room inner opening of above-mentioned put-through channel, be set to its opening when above-mentioned piston moves near top dead center position towards top dead center, and move period closedown at above-mentioned piston from above-mentioned near top dead center position towards lower dead center, and the second opening portion of gas-liquid separation device is connected with above-mentioned put-through channel.

Owing to having such structure, the lubricant oil be separated by gas-liquid separation device can be made efficiently to be recycled to oil circulation path.

According to an aspect of the lubricating fitting of four stroke engine of the present invention, pressure change in the crankshaft room that its utilization produces because of the to-and-fro motion of piston, above-mentioned oil circulation path is used to make lubrication oil circulation, thus the lubrication of carrying out each portion, it is characterized in that, be provided with in above-mentioned crankshaft room as being communicated with the second opening portion of gas-liquid separation device and the return flow line of above-mentioned crankshaft room during negative pressure, the open end to above-mentioned crankshaft room inner opening of above-mentioned return flow line, be set to its opening when above-mentioned piston moves near top dead center position towards top dead center, and move period closedown at above-mentioned piston from above-mentioned near top dead center position towards lower dead center.

Owing to having such structure, the lubricant oil be separated by gas-liquid separation device can be made efficiently to be recycled to oil circulation path.

According to an aspect of the lubricating fitting of four stroke engine of the present invention, it is characterized in that, there is the 4th opening portion made from the isolated oil return of above-mentioned gas blowby to above-mentioned oil circulation path, at the lower side of above-mentioned first wall on the position in the corner, left and right two of position, be formed with above-mentioned second opening portion and above-mentioned 4th opening portion respectively.

Owing to having such structure, the Grease relief effect of gas-liquid separation chamber can be improved.

the effect of invention

According to the gas-liquid separation device of four stroke engine of the present invention, a kind of gas-liquid separation more positively can carrying out lubricant oil and gas blowby can be provided, thus prevent lubricant oil to be discharged into the gas-liquid separation device of the four stroke engine of firing chamber and the lubricating fitting of four stroke engine.

Accompanying drawing explanation

Fig. 1 is the schematic illustration of the lubricating fitting of the four stroke engine of the present invention first example.

Fig. 2 is the explanatory drawing of air cleaner.

Fig. 3 is the explanatory drawing of oil separator.

Fig. 4 is the structure explanatory drawing of the gas-liquid separation chamber observed from A direction in Fig. 3.

Fig. 5 is the explanatory drawing of Fig. 4 center line V-V section.

Fig. 6 is the explanatory drawing being separated pad, separating grid, separation bounding means, separating plate.

Fig. 7 is working tool as mowing machine the second opening portion when being placed in ground side and the explanatory drawing of the relation between the through hole being separated bounding means.

Fig. 8 be the working tool as olive cropper be placed in ground side opposition side time the explanatory drawing of the second opening portion and the relation between the through hole being separated bounding means.

The explanatory drawing of the shape variation of Tu9Shi gas-liquid separation chamber.

Figure 10 is the explanatory drawing of the variation being separated pad.

Figure 11 is the explanatory drawing of the variation of separating grid.

Figure 12 is the schematic illustration of the lubricating fitting of the four stroke engine of the second example of the present invention.

Figure 13 is the part explanatory drawing of the air purifying plate of other examples of the present invention.

Figure 14 is the schematic illustration of the gas-liquid separation device of other examples of the present invention.

Embodiment

< first example >

The better example of the lubricating fitting of four stroke engine of the present invention is described referring to accompanying drawing 1 to 4.Because lubricating fitting is installed in four stroke engine, therefore utilize Fig. 1 (schematic diagram) that the four stroke engine being provided with this lubricating fitting is described.

In addition, Fig. 1 represents the four stroke engine when piston is positioned at the state of top dead center.

As shown in Figure 1, four stroke engine 1 has cylinder block 3 that cylinder head 3a is integrated, be arranged on cylinder block 3 bottom and form the crankcase 5 of crankshaft room 5a, and is configured in crankcase 5 lower side to the accumulator 7 on position.

Accumulator 7 and crankcase 5 are arranged, separately for storing lubricant oil A.

In the attachment portion of cylinder block 3 with crankcase 5, be rotatably supported with bent axle (not shown), on this bent axle, be connected with piston 6 by counterpoise and coupled connecting rod etc.Piston 6 inserts in the cylinder 3b that is arranged in cylinder block 3 sliding freely.

Being arranged at the upper wall of the cylinder 3b in cylinder block 3, be provided with the suction port and relief opening that are connected with vaporizer (not shown) and muffler (not shown) respectively, in these each ports, be equipped with the suction valve for switch port and outlet valve.

At this, the four stroke engine 1 of this example also can portable use, and now four stroke engine 1 likely uses being temporarily rotated under the state that turns upside down.

Drive the distribution device 10 of these valves, by the valve actuation gear 10a be fixed on bent axle, to be driven by valve actuation gear 10a and to be connected with the cam mechanism 10b of cam, and the parts such as rocking arm (not shown) formed.

In this distribution device 10, valve actuation gear 10a and cam mechanism 10b is housed in and is communicated with in the valve actuation room 32 set by the midway of the service duct 31 of gas distributing chamber that the head of cylinder block 3 is formed 4 and accumulator 7, and the parts such as rocking arm are arranged in gas distributing chamber 4.

Between accumulator 7 and cylinder block 3, be provided with oil supply gallery 34.In the end of the accumulator side of oil supply gallery 34, sucting 35 is installed.

Sucting 35 to have by rubber elastomeric material form, flexible body 35a can be held and be arranged on the spindle 35b with suction port of the tip portion of body 35a.

The spindle 35b of sucting 35 is arranged on position, vertical lower side direction movably by gravity, therefore, even if accumulator 7 tilts, below the pasta of the lubricant oil A that the scope that the suction port of sucting 35 also can be made to submerge measure according to the rules stores.

Oil supply gallery 34 is, when the rising due to piston 6 makes to occur that negative pressureization is inclined in crankshaft room 5a, be communicated with in crankshaft room 5a with accumulator 7 and the part that is supplied to from accumulator 7 suck lubrication oil A in crankshaft room 5a.

To the open end 34a of the crankshaft room 5a side opening of oil supply gallery 34, be arranged on piston 6 and move period near top dead center position towards top dead center with the movement of piston 6 and the position of opening, be positioned at the side, 6a lower dead center direction, skirt section of the piston lower portion to the movement of near top dead center position.

Therefore, when piston 6 arrives top dead center, the open end 34a of oil supply gallery 34 has been in the state of opening completely.

In addition, oil supply gallery 34, by arranging leaf valve on its open end 34a, or arranges passage and makes it play a role as rotary valve, when being the state of negative pressure in crankshaft room 5a, also can be communicated with oil supply gallery 34 and crankshaft room 5a on bent axle.

One-way valve 37 is provided with in the midway of oil supply gallery 34.This one-way valve 37 is set to the opening and closing along with the pressure change in crankshaft room 5a, opens, makes oil supply gallery 34 become connected state, and close when pressure in crankshaft room 5a is higher under the state of the pressure in crankshaft room 5a lower than the pressure in accumulator 7.

Between the bottom of crankshaft room 5a and accumulator 7, be provided with the runner 39 being communicated with crankshaft room 5a and accumulator 7.This runner 39 is delivered to accumulator 7 for the lubricant oil generated that the mist of oil generated in crankshaft room 5a and this mist of oil liquefied.

Open end 39a to crankshaft room's side opening of runner 39 is provided with leaf valve 40.This leaf valve 40 is set to the opening and closing along with the pressure change in crankshaft room 5a, and the malleation in crankshaft room when being moved to lower dead center side by piston 6 and opening, makes runner 39 become connected state.

Therefore, if leaf valve 40 is opened and runner 39 is in connected state, then the mist of oil in crankshaft room 5a and lubricant oil will be delivered in accumulator 7 via runner 39.

The space portion 7a of accumulator 7 separated by the dividing plate 7c having pad function concurrently.

The upper side direction position of dividing plate 7c is formed with the open end 31a of service duct 31.

The open end 39b of the accumulator side of runner 39, the substantial middle place opening in accumulator 7, regardless of the heeling condition of accumulator 7, is configured in and stores not higher than the position more than pasta of the lubricant oil A of established amount.

Therefore, the mist of oil that lubricant oil inside can not be discharged because of the open end 39b from runner 39 is ejected into below lubricant oil pasta and bubbles, and mist of oil can be back to accumulator 7 reposefully, and most mist of oil will be liquefied.

But, from open end 39b discharge a part of mist of oil can on pasta and wall rebound, be trapped in the space portion 7a of side direction position on the pasta in accumulator 7.So be configured in the open end 39b of the runner 39 of the above position of pasta of lubricant oil A, a part for the liquid body as liquefaction mist of oil is played a role.

Therefore, from the mist of oil that runner 39 is discharged, its major part will be liquefied, thus can reduce the oil mist concentration be stored in accumulator 7.

The open end 31a of service duct 31, the substantially central portion opening of the inner space in accumulator 7, regardless of the heeling condition of accumulator 7, do not change higher than the oil surface level of the lubricant oil A of established amount even if store, be configured to not make below its pasta that submerges yet.In addition, as shown in Figure 1, be configured to relative to open end 31a, open end 39b is more outstanding.

As mentioned above, the open end 39b of runner 39 is configured to protrude from accumulator 7 than the open end 31a of service duct 31, and the mist of oil of therefore discharging from the open end 39b of runner 39 directly can not enter the open end 31a of service duct 31.It is further preferred that runner 39 and service duct 31 also can be configured in along with on the direction before each open end side and then away from adjacent open end.

Namely, the plane vertical relative to the bearing of trend (direction represented by dashed line) with runner 39 in open end 39b, if the open end 31a of service duct 31 and near be configured in the bottom side of runner 39, then the mist of oil of discharging from runner 39 directly can not enter the open end 31a of service duct 31.

Namely, the service duct 31 of accumulator 7 and the configuration of runner 39 play a role as the inflow blocking portion stoping the mist of oil of discharging from runner 39 to flow directly into the open end 31a of service duct 31.

Therefore, the oil mist concentration of service duct 31 is flow through lower than the concentration of lubricating oil be supplied to from oil supply gallery 34 in crankshaft room 5a.

The open end 31b of gas distributing chamber 4 side of service duct 31, to cylinder block 3 side opening of gas distributing chamber 4.Therefore, flow through the distribution device 10 in the oil mist lubrication valve actuation room 32 of service duct 31, and discharge from open end 31b and be supplied to the rocking arm etc. lubricated in gas distributing chamber 4 in gas distributing chamber 4.

Gas distributing chamber 4 is communicated with by push rod passage 33 with valve actuation room 32.

This push rod passage 33 is communicated to gas distributing chamber 4 by open end 31b.

Push rod this push rod passage 33 through, push rod drives the rocking arm in gas distributing chamber 4.

In addition, the wall member 45 of overshooting shape in gas distributing chamber 4, is formed with, for isolating mist of oil and liquefaction lubrication wet goods by the fluid flowed into from push rod passage 33 in gas distributing chamber 4 (mist of oil, liquefaction lubricant oil, gas blowby).

Multiple suction tube 43 for sucking the lubricant oil of alluvial in gas distributing chamber 4 is provided with in gas distributing chamber 4.

The open end 43a of gas distributing chamber 4 side of suction tube 43 is to cylinder block 3 side opening of gas distributing chamber 4.

And suction tube 43 is connected with attraction channel 42.Attraction channel 42 is arranged on the opposition side of the crankshaft room 5a of gas distributing chamber 4, and suction tube 43 is arranged to coupled leading to and extends to the crankshaft room side in gas distributing chamber 4, and the top of suction tube 43 is in opening state.

In order to from the crankshaft room side bottom surface sucking-off lubricant oil in gas distributing chamber 4, the open top end of suction tube 43 is configured in the neighbouring position of the bottom surface, crankshaft room side of gas distributing chamber 4.

Further, suction tube 43 is configured in the corner of gas distributing chamber 4, though four stroke engine 1 be positioned at side direction position in gas distributing chamber 4 state under run-off the straight, also can by the lubricant oil of arbitrary suction tube 43 sucking-off alluvial in gas distributing chamber 4.

In addition, attraction channel 42 is provided with multiple aperture 44.This aperture 44 is configured in the corner of the crankshaft room 5a opposition side of gas distributing chamber 4, even if four stroke engine 1 is positioned at lower side to run-off the straight under the reverse state of position in gas distributing chamber 4, and also can by the lubricant oil of arbitrary aperture 44 sucking-off alluvial in gas distributing chamber 4.

Attraction channel 42 is provided with put-through channel 46, and when being negative pressure state in crankshaft room 5a, gas distributing chamber 4 is connected by put-through channel 46 with crankshaft room 5a.

The position of the open end 46a of the crankshaft room side of put-through channel 46, identical with the open end 34a of oil supply gallery 34, be arranged on piston 6 and move period near top dead center position towards top dead center with the movement of piston 6 and the position of opening, be positioned at the side, lower dead center direction of the skirt section 6a of the piston lower portion to the movement of near top dead center position.

Therefore, when piston 6 reaches top dead center, the open end 46a of put-through channel 46 has been in the state of opening completely.

In addition, put-through channel 46 also can be arranged and allow from gas distributing chamber 4 and move to crankshaft room's 5a effluent, and limit the lubricant oil one-way valve dynamic from crankshaft room 5a to gas distributing chamber 4 effluent.

By above setting, lubricant oil and mist of oil can be prevented definitely from crankshaft room 5a to gas distributing chamber 4 adverse current.

One end of breathing pipe 48 is to the substantial middle opening of gas distributing chamber 4, and the other end of breathing pipe 48 is connected with air cleaner 50.

Breathing pipe 48 is arranged to be disposed to for the purpose of firing chamber by gas blowby.Mist of oil in gas distributing chamber 4 and gas blowby, be delivered to air cleaner 50 by breathing pipe 48, and to be become lubricant oil and the gas blowby of liquefaction by gas-liquid separation by being arranged on oil separator 51 in air cleaner 50.

One end 48a of breathing pipe 48 due to the substantial middle opening to gas distributing chamber 4, even if so be detained a large amount of lubricant oil in gas distributing chamber 4, also this lubricant oil can not be sucked simply.This breathing pipe 48 is provided with one-way valve, and prevents gas blowby and mist of oil from air cleaner 50 to gas distributing chamber 4 side adverse current by this one-way valve.

Lubricant oil after gas-liquid separation, is delivered to crankshaft room 5a by the return flow line 52 being communicated with air cleaner 50 and crankshaft room 5a.Be provided with in return flow line 52 and only allow to the dynamic one-way valve of crankshaft room's effluent.On the other hand, the gas blowby after gas-liquid separation is transported to firing chamber.

Between the bottom and crankshaft room 5a of the accumulator side of valve actuation room 32, be provided with for making the lubricant oil in valve actuation room 32 backflow to the reflux passage 54 in crankshaft room 5a.When being negative pressure in crankshaft room 5a, by the lubricant oil of reflux passage 54 sucking-off alluvial in valve actuation room 32.This reflux passage 54 is configured to 1/10 of the sectional area being less than runner 39.

When being malleation in crankshaft room 5a, leaf valve 40 is opened, and crankshaft room 5a and accumulator 7 are in connected state.Mist of oil in crankshaft room 5a and lubricant oil flow through the larger runner of sectional area 39, and reflux passage 54 is in the state of lubricated oil blocking, so lubricant oil substantially can not from crankshaft room 5a adverse current to valve actuation room 32.In the present embodiment, the internal diameter of runner 39 is set to φ 9mm, the internal diameter of reflux passage 54 is set to φ 2mm.

In addition, reflux passage 54 also can be set to be communicated with valve actuation room 32 and above-mentioned put-through channel 46.By setting like this, reflux passage 54 would not to the lubricant oil of gas distributing chamber 4 glut.

In addition, also can arrange in reflux passage 54 and allow that lubricant oil moves to crankshaft room's effluent, limit lubricant oil to the dynamic one-way valve of valve actuation room 32 effluent.Setting like this, just can prevent lubricant oil from adverse current in crankshaft room 5a to side, valve actuation room 32 definitely.

In addition, between valve actuation room 32 and oil supply gallery 34, be provided with flow adjustment passage 56.

Flow adjustment passage 56, by sucking the air in valve drive chamber 32, adjusts the flow of lubrication being supplied to crankshaft room 5a by oil supply gallery 34.

If the intake of this air is more, by oil supply gallery 34, the flow of the lubricant oil of supply will reduce.In addition, flow adjustment passage 56 with the bottom be arranged on away from valve actuation room 32 and the position being difficult to suck the lubricant oil be trapped in valve actuation room 32 be advisable.

Flow adjustment passage 56 and the link position of oil supply gallery 34, be positioned at than the one-way valve 37 be arranged on oil supply gallery 34 closer to accumulator side.

Therefore, if utilize one-way valve 37 to cut off the supply of lubricant oil, then by than one-way valve 37 closer to the lubricant oil that deposits in the oil supply gallery 34 of accumulator side, and to deposit lubricant oil at flow adjustment passage 56 and the connection part of oil supply gallery 34.

Therefore, when oil supply gallery 34 sucks air from flow adjustment passage 56, air can not be only had to flow through oil supply gallery 34, and the lubricant oil in oil supply gallery 34 can together be delivered to crankshaft room 5a with the air carried from valve actuation room 32.

Be provided with for adjusting the throttle valve 57 being transported to the air mass flow of oil supply gallery 34 from valve actuation room 32 in this flow adjustment passage 56.

Adjust by adjustment throttle valve 57 air quantity sucked from valve actuation room 32, thus the flow of lubrication being supplied to crankshaft room 5a by oil supply gallery 34 can be adjusted.That is, the internal diameter of flow of forgetting it adjustment passage 56, the design by means of only throttle valve 57 just can adjust flow of lubrication simply.

In addition, throttle valve 57 is arranged separately without the need to adjusting passage 56 with flow, also can be the part being configured to flow adjustment passage 56.Such as, the sealing surface along cylinder block 3 and crankcase 5 forms the part that flow adjusts passage 56, once be connected with oil supply gallery 34 on sealing surface, just can form throttle valve 57 very simply.

That is, the lubrication oil circulation path of lubricating fitting 30 is configured to comprise: oil supply gallery 34, runner 39, service duct 31, push rod passage 33, suction tube 43, aperture 44, attraction channel 42, put-through channel 46, breathing pipe 48, return flow line 52, reflux passage 54 and flow adjustment passage 56.

If four stroke engine 1 starts, due to the pressure change that the elevating movement of piston 6 will produce in crankshaft room 5a, pressure when piston 6 rises in crankshaft room 5a reduces and occurs that negative pressureization is inclined to, and the pressure when piston 6 declines in crankshaft room 5a raises and occurs that malleationization is inclined to.

If occur that negative pressureization is inclined in crankshaft room 5a, the open end 34a of oil supply gallery 34 starts to open to the movement of near top dead center with piston 6, and when crankshaft room 5a is connected with accumulator 7, the negative pressure in crankshaft room 5a will act on oil supply gallery 34.

Even if four stroke engine 1 run-off the straight, the sucting 35 of oil supply gallery 34 is still in the state of below the lubricant oil A pasta of the accumulator 7 that submerges, and sucks lubricant oil A and be delivered in crankshaft room 5a from accumulator 7.When piston 6 arrives top dead center, open end 34a has been in the state of opening completely, so the negative pressure in crankshaft room 5a can be acted on oil supply gallery 34 fully.

Therefore, the lubricant oil A drawn below pasta can be supplied fully in crankshaft room 5a.

Be transported to the lubricant oil in crankshaft room 5a, while the driver parts such as lube pistons 6, bent axle, the formation mist of oil that disperses by these driver parts.Part mist of oil is attached to the wall of crankshaft room 5a and is again liquefied.

When piston 6 declines from top dead center, become barotropic state in crankshaft room 5a, leaf valve 40 is open, and crankshaft room 5a is connected with accumulator 7.Then, the mist of oil boosted in crankshaft room 5a and lubricant oil are delivered to accumulator 7 via runner 39, and the pressure in accumulator 7 raises.The mist of oil of discharging from runner 39 occurs to collide with the pasta of lubricant oil A deposited in accumulator 7 and the wall of accumulator 7 and liquefies, and is stored in accumulator 7.

Collide in accumulator 7 internal cause and rebound and residual oil mist concentration, lower than the oil mist concentration in crankshaft room 5a.

In addition, if become barotropic state in crankshaft room 5a, will the effect of one-way valve 37 be utilized to cut off oil supply gallery 34, thus stop lubricant oil from crankshaft room 5a adverse current to accumulator 7, then close open end 34a by piston 6.

Because the pressure in accumulator 7 raises, produce pressure gradient in accumulator 7 and between gas distributing chamber 4, the mist of oil deposited in accumulator 7 will be delivered to gas distributing chamber 4 by service duct 31.

Carrying in the process of mist of oil from accumulator 7 to gas distributing chamber 4, each parts being arranged on the distribution device 10 in the valve actuation room 32 on service duct 31 are lubricated.Now, a part of mist of oil will be liquefied.

The lubricant oil be not liquefied in valve actuation room 32, can be delivered to crankshaft room 5a by reflux passage 54.

Therefore, lubricant oil not only can be suppressed excessively to be trapped in valve actuation room 32, lubricant oil can also be suppressed to flow out to gas distributing chamber 4.In addition, can also prevent lubricant oil from blocking service duct 31.

The oil mist lubrication being supplied to gas distributing chamber 4 is arranged on the distribution device in gas distributing chamber 4, and is delivered to crankshaft room 5a by put-through channel 46.

In addition, even if the mist of oil be supplied in gas distributing chamber 4 liquefies and is detained, the strong negative pressure in crankshaft room 5a still plays a role, and not only can carry lubricant oil in crankshaft room 5a, can also restrain lube oil retention in gas distributing chamber 4.

Therefore, when discharging gas blowby from gas distributing chamber 4 by breathing pipe 48, the release of lubricant oil can be suppressed.

Fig. 2 is the explanatory drawing of air cleaner 50.

In this definition direction.Upper side direction in this example, the vertical upper side direction (above the paper in Fig. 2) in position relationship when referring to the keeping not using four stroke engine 1 etc.

On this, side direction is basically identical with the vertical upper side direction of the maximum duration using state being in four stroke engine 1 in using state.The direction contrary with side direction on this is called that lower side is to (below the paper in Fig. 2).

In addition, rod member 60 side tip portion being provided with the various instruments driven by four stroke engine 1 is defined as rod member side direction (in fig. 2, for paper is to upper left).Rod member side in the other direction (in fig. 2, for paper to the right to) is called in the opposite direction with this rod member side.

In addition, be through with transmission shaft in rod member 60, this transmission shaft is connected with the Power Available Shaft of four stroke engine 1.In addition, this transmission shaft is also connected with various instrument.As a result, various instrument is driven by the power of four stroke engine 1.

Further, the direction contrary with the installation side of the four stroke engine 1 being provided with air cleaner 50, is called lateral direction (in fig. 2, being paper direction to left down).Interior side direction (in fig. 2, for paper is to upper right) is called in the opposite direction with this outside.

In addition, the so-called position relationship reversed, refers in the flow direction of two fluids, even if extend the central shaft of both sides' flow direction, flow direction also can not the position relationship of intersection mutually.

Direction used in FIG is all based on above-mentioned definition.

As shown in Figure 2, in four stroke engine 1, tip portion etc. are provided with the rod member 60 of the instrument driven by this four stroke engine 1, are connected on this rod member side direction.

This four stroke engine 1 is used in mowing machine (with reference to Fig. 7 (a)) or olive cropper (with reference to Fig. 8 (a)).And if mowing machine, rod member 60 is along with the situation closely tilting to use earthward away from four stroke engine more (with reference to Fig. 7 (a)).In addition, if olive cropper, along with away from four stroke engine to away from ground direction tilt use situation then more (with reference to Fig. 8 (a)).

And, when stem member 60 is set as forward direction, the position of side direction on the left surface that air cleaner 50 is configured at four stroke engine 1.

Air cleaner 50 there is draw air and remove contain in this air dust and rubbish, provide air to the function of gas handling system, further, in this example, there is function gas blowby being delivered to gas handling system.

Air cleaner 50 by be fixed on four stroke engine 1 side air purifying plate 50b and removably air purification lid 50a form its shell.

In the inner space formed by this air purifying plate 50b and air purification lid 50a, there is the space for removing dust and rubbish in air, i.e. air purification space 50d and gas-liquid separation space 50c.

In the 50d of air purification space, be configured with the first air purification filter part 50e by rubbish and dust in filtering function removing air and the second air purification filter part 50f.

Second air purification filter part 50f is configured in than the first air purification filter part 50e closer to air purifying plate 50b side.

In addition, the first air purification filter part 50e is formed by sponge etc., and the second air purification filter part 50f is formed by felt etc.

Fig. 3 is the explanatory drawing of oil separator 51.

As shown in Figure 3, oil separator 51 formed by the gas-liquid separation space 50c of air cleaner 50, separating plate 501 and gas-liquid separate component 601.

In addition, separating plate 501 is configured in gas-liquid separation space 50c and air purification passage configuration section 113.

The air purification passage configuration section 113 that gas-liquid separation space 50c is communicated with air purification space 50d, is formed at the reciprocal position, rod member side of the rod member 60 of air purification space 50d.

Gas-liquid separation space 50c is dimetric first wall 101 by the summary being formed at interior side direction, and formed the side that this first wall 101 extends in outward direction as base.In addition, gas-liquid separation space 50c is towards lateral direction opening.

This side formed by the first side 109, side 107, second and the 3rd side 111.First side 109, side 107, second and the 3rd direction toward the outer side, side 111, formed by the order of the first side 109, side 107, second and the 3rd side 111.

First side 109, side 107, second and the 3rd side 111 are (in the lump with reference to Fig. 5) of being formed to become large mode by the sequential openings of the first side 109, side 107, second and the 3rd side 111.

In the 50c of gas-liquid separation space, be separated pad 201, separating grid 301, be separated bounding means 401 and separating plate 501, sequentially configured toward lateral direction from first wall 101.

At this, be separated pad 201, separating grid 301 and separation bounding means 401 and constitute gas-liquid separate component 601.

In the space formed by the first side 107, be configured with and be separated pad 201, separating grid 301 and be separated bounding means 401.

In the space that the second side 109 is formed, be configured with separating plate 501.

The first opening portion 103 be communicated with breathing pipe 48 is formed near the central authorities of first wall 101.In addition, rod member side direction position is formed with to position the second opening portion 105 be communicated with return flow line 52 at the lower side of first wall 101.

And as shown in Figure 4, the second opening portion 105 is positioned at the corner in left side.

Certainly, if corner also can be arranged on right side, but the left side being equivalent to rod member side direction is best.

The second wall 501d is formed in the face of the lateral direction of separating plate 501.

And, on the reciprocal position, rod member side of this second wall 501d, be formed with the 3rd opening portion 501g being communicated with air purification passage 501c.

Gas-liquid separation chamber 117 (with reference to Fig. 5) is formed by this second wall 501d, first wall 101 and the first side 107.

Gas blowby containing the mist of oil flowed into from the first opening portion 103, first, isolates the large oil of oil droplet in mist of oil by separation pad 201.

Specifically, be that isolate cannot by being formed at the mist of oil of middle thereof hole 201d being separated pad 201.

Isolated mist of oil liquefaction, the lubricant oil after liquefaction, by the second opening portion 105, discharges from gas-liquid separation chamber 117.

In addition, though the gas componant containing lubricant oil in gas blowby, conveniently only gas blowby is described as.

In addition, have passed the gas blowby containing mist of oil being separated pad 201, by netted separating grid 301.Thus, utilize mesh portion from gas blowby, isolate the little mist of oil of oil droplet.

The liquefaction of isolated mist of oil, the lubricant oil after liquefaction by be formed at be separated pad 201 pad corner through hole 201c after, by the second opening portion 105, discharge from gas-liquid separation chamber 117.

The gas blowby containing mist of oil that have passed separating grid collides the wall being separated bounding means 401, isolates mist of oil by this from gas blowby.

Then, the liquefaction of isolated mist of oil, the lubricant oil after liquefaction by separating grid 301, by be formed at be separated pad 201 pad corner through hole 201c after, by the second opening portion 105, discharge from gas-liquid separation chamber 117.

Collide the gas blowby be separated after bounding means 401, by being formed at the through hole 401c be separated on bounding means 401.

Then, collide by the gas blowby of this through hole 401c the second wall 501d being formed at separating plate 501, be directed into the 3rd opening portion 501g.Then, from the 3rd opening portion 501g by air purification passage 501c, air purification space 50d is directed into.

Afterwards, in the 50d of air purification space, gas blowby is mixed into via in the first air purification filter part 50e and the second air purification filter part 50f filtered air.

Then, be mixed into the gas blowby in air inlet, burn in a combustion chamber.

Fig. 4 is the structure explanatory drawing of the gas-liquid separation chamber 117 observed from A direction in Fig. 3.

Fig. 4 is presented in the 50c of gas-liquid separation space the state being only configured with and being separated pad 201.

As shown in Figure 4, the first opening portion 103 is formed with at the middle position of first wall 101.In addition, in lower side to position rod member side direction position is formed with the second opening portion 105.

The protuberance 114 given prominence to slightly in outward direction than first wall 101, formed in the mode of surrounding the first opening portion 103 is formed in first wall 101.

Owing to having this protuberance, therefore form the ditch portion 116 of encirclement first opening portion 103.There is cunette shape in ditch portion 116 for what be formed at first wall 101.

Ditch portion 116 is from the long limit, up side direction and the lower side that extend in the other direction toward rod member side direction and rod member side to the minor face extended, the rectangular ditch of formation.

Fit tightly first wall 101 by being separated pad 201, thus cover the top in this ditch portion 116, make it become duct-like shape.

The passage of this duct-like shape is called lubricant oil return passage 115.

In addition, on the position corresponding with each angle with OBL ditch portion 116, the pad corner through hole 201c being separated pad 201 is formed.

At this, periodically change negative pressure into by crankshaft room 5a, periodically sucking fluid from the second opening portion 105, therefore this lubricant oil return passage 115, just looks like the function achieved as suction pipe.

By the function as this suction pipe, be separated and the lubricant oil liquefied by separating grid 301 and separation bounding means 401, by pad corner through hole 201c, backflow to return flow line 52 from the second opening portion 105, can again utilize as lubricant oil.

Chamfered section 105a is formed around the second opening portion 105.This chamfered section 105a has the shapes such as circular cone shape.By this, the middle thereof hole 201d separation of separated pad 201, the lubricant oil of liquefaction are backflowed to return flow line 52 from the second opening portion 105.

Fig. 5 is the explanatory drawing of Fig. 4 center line V-V section.

Fig. 5 and Fig. 4 is different, is to add to be separated pad 201, is configured with separating grid 301, the explanatory drawing of V-V section when being separated bounding means 401 and separating plate 501.

Make the first opening portion 103 that gas-liquid separation chamber 117 is communicated with breathing pipe 48, and the second opening portion 105 that gas-liquid separation chamber 117 is communicated with return flow line 52, be formed at first wall 101.

In addition, breathing pipe 48 and return flow line 52 are formed abreast.

Sequentially be configured with from first wall 101 side and be separated pad 201, separating grid 301, be separated bounding means 401 and separating plate 501.

In addition, the first side 109, side 107, second and the 3rd side 111 is sequentially formed with from first wall 101 side.

And, from first wall 101 side, the first side 109, side 107, second and the 3rd side 111 with side direction on it and lower side to height and the sequentially elongated mode of the reciprocal width of rod member side direction and rod member side and being formed.

In this first side 107, be configured with and be separated pad 201, separating grid 301, be separated bounding means 401.In addition, in the second side 109, separating plate 501 is configured with.

In the inside of separating plate 501, be formed with the trench gas blowby reduced space 501i the second wall 501d towards first wall 101 being used as bottom surface, intralamellar part side 501h being used as side.

This gas blowby reduced space 501i is communicated to air purification passage 501c via the 3rd opening portion 501g.

In addition, gas-liquid separation chamber 117 is formed by the second wall 501d, first wall 101 and the first side 107.

Fig. 6 is the explanatory drawing being separated pad 201, separating grid 301, separation bounding means 401, separating plate 501.

Fig. 6 (a-1) is the figure of the separating plate 501 observed by the B side of Fig. 3.The sectional drawing that Fig. 6 (a-2) is Fig. 6 (a-1).

Separating plate 501 by plate main body portion 501a, and in upper side direction position and the air purification passage 501c that rod member side in the other direction position is formed formed.

Air purification passage 501c has towards upper side direction, to inward side to the shape of the tubulose tilted.

In plate main body portion 501a, be formed with the gas blowby reduced space 501i the second wall 501d being used as bottom surface, intralamellar part side 501h being used as side, being formed as the ditch of flat column.

This gas blowby reduced space 501i, via plate passage 501e, is communicated with opening portion i.e. the 3rd opening portion 501g of air purification passage 501c.

This plate main body portion 501a is formed by having flexible rubber etc., by being pressed in the second side 109, also has pad function.

On the lateral direction position of plate main body portion 501a, be configured with sheet metal and the panel beating plate 501b for keeping separating plate 501 intensity.

Fig. 6 (b-1) is the figure of the separation bounding means 401 observed by the B side of Fig. 3.The sectional drawing that Fig. 6 (b-2) is Fig. 6 (b-1).

The bounding means main body portion 401a being separated bounding means 401 has rectangular tabular.

In the rod member side direction position of bounding means main body portion 401a upper side direction position is formed with through hole 401c.

This bounding means main body portion 401a is formed by having flexible rubber etc., by being pressed in the first side 107, also has pad function.

On the lateral direction position of bounding means main body portion 401a, be configured with sheet metal and the panel beating plate 401b for keeping being separated bounding means 401 intensity.

Fig. 6 (c-1) is the figure of the separating grid 301 observed by the B side of Fig. 3.The sectional drawing that Fig. 6 (c-2) is Fig. 6 (c-1).

The net main body portion 301a of separating grid 301 has rectangular tabular.

This net main body portion 301a formed by weaving webbed thread-like member.

The grid of this mesh members is less, and the separation effect of mist of oil is then higher.

Fig. 6 (d-1) is the figure of the separation pad 201 observed by the B side of Fig. 3.The sectional drawing that Fig. 6 (d-2) is Fig. 6 (d-1).

The shim body portion 201a being separated pad 201 has rectangular tabular.

Middle thereof hole 201d is formed at the central part of this shim body portion 201a.

Middle thereof hole 201d is formed as there is one in central authorities, then in the upper side direction position in the hole of these central authorities, lower side to position, rod member side direction position, rod member side respectively have one in position in the other direction.

In addition, pad corner through hole 201c is formed with respectively in four corners of shim body portion 201a.

This shim body portion 201a is formed by having flexible rubber etc., by being pressed in the first side 107, also has pad function.Particularly by being crimped on the protuberance 114 of first wall 101, there is the function forming lubricant oil return passage 115.

Sheet metal and the panel beating plate 201b for keeping being separated pad 201 intensity is had in the internal configurations of shim body portion 201a.

Fig. 7 is working tool as mowing machine the second opening portion 105 when being placed in ground side and the explanatory drawing of the relation between the through hole 401c being separated bounding means 401.

Fig. 7 (a) is working tool and mowing machine figure when being connected to rod member 60.In addition, as shown in Fig. 7 (a), air cleaner 50 in four stroke engine 1, is connected with.

Then, the part of the air cleaner 50 of Fig. 7 (a) and rod member 60 are illustrated in Fig. 7 (b).

In addition, the description of Fig. 7 (b) eliminates the main body portion of four stroke engine 1.

Incidentally, if pasta 119 arrives the through hole 401c place being separated bounding means 401, lubricant oil just can pass through this through hole 401c, invades the gas blowby reduced space 501i(of separating plate 501 as shown in Figure 5).Thus, lubricant oil will be supplied to air purification space 50d in large quantities via air purification passage 501c.

As a result, produce lubricant oil to be consumed in a large number and lubricant oil becomes the problem that cannot be sufficiently burned.

Therefore, in this example, as shown in Fig. 7 (b), the through hole 401c of the second opening portion 105 and separation bounding means 401 is formed at rod member 60 side, namely on rod member side direction position.

In addition, as shown in Figure 13, Figure 14, the opposite location of rod member 60 forms the 4th opening portion 106, in order to be communicated with return flow line 52, to improve the emission effect of the lubricant oil in gas-liquid separation chamber 117.

If form above-mentioned situation, the working tool being configured at rod member 60 top be positioned at than four stroke engine 1 closer to the state of ground side position under operation time (such as, when four stroke engine 1 is for mowing machine), air cleaner 50 can tilt as Fig. 7 (a).

Thus, as shown in Fig. 7 (b), at separation the bounding means 401 and lubricant oil be separated between pad 201, will deposit in rod member side direction position and lower side on position.

In this case, lubricant oil contacts the second opening portion 105 part, is discharged all the time by the second opening portion 105.

In addition, also identical with the lubricant oil be separated between pad 201 at first wall 101.

Therefore, as shown in Fig. 7 (b), under the pasta 119 of the lubricant oil in gas-liquid separation chamber 117 often remains on lower state.

Also therefore, in this case, can not produce lubricant oil consume in a large number and lubricant oil become cannot clean-burning problem.

Fig. 8 be the working tool as olive cropper be positioned at the opposition side of ground side position time, its second opening portion 105 and the relation explanatory drawing between the penetration hole 401c being separated bounding means 401.

Fig. 8 (a) is the figure that working tool and olive cropper are connected to rod member 60.

As shown in Fig. 8 (a), the working tool being sometimes placed in rod member 60 top be positioned at than four stroke engine 1 closer to the state of opposition side position, ground under operation (when such as, four stroke engine 1 is used in olive cropper).

In addition, even if what the working tool being configured at rod member 60 top was installed during operation under the state being more positioned at ground side position than four stroke engine 1 is general purpose tool (such as, the instrument of mowing machine), according to circumstances, the working tool being configured at rod member 60 top is also likely temporary transient or for good and all operation under the state being more positioned at opposition side position, ground than four stroke engine 1.

In addition, no matter the working tool that is configured at rod member 60 top than four stroke engine 1 closer to the state of ground side position under operation, still the working tool being configured at rod member 60 top than four stroke engine 1 closer to the state of opposition side position, ground under operation, also have the instrument that can carry out both sides' operation to be installed on the situation of four stroke engine 1.

In these cases, be temporarily or often the state shown in Fig. 8 (b) in operation.

That is, to deposit in rod member side in the other direction position and lower side of this pasta 119, on position, deposits frequently to pasta 119a.And pasta 119 temporarily will rise to the level of pasta 119b.

If this is because pasta 119 does not rise to the position of the second opening portion 105 discharging lubricant oil from gas-liquid separation chamber 117, just lubricant oil cannot be discharged from gas-liquid separation chamber 117.

But even if in this case, because the second opening portion 105 and through hole 401c are formed at rod member side direction position, therefore, pasta 119 can not arrive the through hole 401c place being separated bounding means 401.

That is, the second opening portion 105 and through hole 401c are formed at rod member side direction position, can prevent the problem that lubricant oil consumes in a large number by this, and the generation of the not clean-burning problem of lubricant oil.

The explanatory drawing of the shape variation of Tu9Shi gas-liquid separation chamber 117.

In above-mentioned example, as shown in Fig. 9 (a), gas-liquid separation chamber 117 formed by rectangular first wall 101 and perpendicular the first side 107 erected, and is rectangular shape.

And the first opening portion 103 is formed on the middle position of this first wall 101, the second opening portion 105 is formed at lower side to position and on rod member side direction position.

Then, if four stroke engine 1 be inclined to make rod member side in the other direction slightly under (for turning clockwise in Fig. 9 (a)), lubricant oil can not touch the second opening portion 105, have the anxiety cannot carrying out the discharge of lubricant oil.

Therefore, in Fig. 9 (b), change lower side in the first side 107 to position and the shape of the wall portion 121 of rod member in the other direction on side position.

This wall portion 121 has than the second opening portion 105 shape that more upwards side direction is outstanding.

This wall portion 121 also can have the shape as Fig. 9 (c).

That is, outstanding wall portion 121 has the shape that upwards side direction is outstanding, as long as lubricant oil also concentrates on the shape of the second opening portion 105 side when four stroke engine 1 is in the state do not tilted.

Figure 10 is the explanatory drawing of the variation being separated pad 201.

In above-mentioned example, as shown in Figure 10 (a), four corners being separated pad 201 are formed with circular pad corner through hole 201c.The shape of this pad corner through hole 201c can be arbitrary shape.

In addition, as shown in Figure 10 (b), also can in rod member side direction position and lower side forms breach 201e on position.

The position forming this breach 201e also can be identical with the position being formed with the second opening portion 105.

Thus, by making the position of otch 201e identical with the position of the second opening portion 105, the lubricant oil be separated by separating grid 301 and separation bounding means 401 can be directed to the second opening portion 105 relatively easily.

That is, because be the structure sucking lubricant oil from the second opening portion 105, therefore maximum lubricant oil will be drawn into from the front position of the second opening portion 105.

Therefore, in order to make most lubricant oil move smoothly through, be positioned at the pad corner through hole 201c of the second opening portion 105 front position, comparatively suitable to have larger through hole shape.

By this, otch 201e is suitable for guaranteeing large discharge path.

In addition, otch 201e also can be simple large through hole shape.

Figure 11 is the explanatory drawing of the variation of separating grid 301.

In the above-described embodiments, as shown in Figure 11 (a), net main body portion 301a formed by net entirely.

But, all ununified necessity.

Such as, as shown in Figure 11 (b), also can form sponge portion 301b in the forming position of the second opening portion 105.

Thus, by forming above-mentioned sponge portion 301b, sponge portion 301b by adsorpting lubrication oil, thus can prevent spilling from air cleaner.

In addition, even if formed by net, also can be that the grid that the central authorities of net main body portion 301a are neighbouring (being formed with the vicinity of the middle thereof hole 201d being separated pad 201) is comparatively thin, and the grid of other parts be thicker.

By above formation, the part that grid is thinner can liquefy mist of oil effectively, and the part that grid is thicker (sponge portion 301b) can make the lubricant oil of post liquefaction be directed to the second opening portion 105 place more swimmingly.

< second example >

Figure 12 is the schematic illustration of the lubricating fitting of the four stroke engine of the second example of the present invention.

In the first example, return flow line 52 is connect via oil supply gallery 34 with the connection of crankshaft room 5a, but in the second example shown in Figure 12, return flow line 52 is connected to put-through channel 46.In addition, the part explanation identical with the first example is omitted.

Then, the open end to the crankshaft room 5a opening of side, return flow line 52 is set to, the opening when piston 6 moves near top dead center position towards top dead center, and moves period closedown at piston 6 near top dead center position towards lower dead center.

By above-mentioned structure, the lubricant oil A be separated by oil separator 51 can be reclaimed expeditiously in oil circulation path.

Then, if can in oil separator 51 separation lubrication oil A, thus make lubricant oil A backflow to oil circulation path expeditiously, then the lubricant oil be separated would not be sent to firing chamber, can prevent consuming excessively of lubricant oil A.

Certainly, in order to make the circulation oil mass of lubricant oil A stablize, the connection of return flow line 52 and crankshaft room 5a is preferably via put-through channel 46 or directly connect.

Below, the reason constructed as shown in Figure 2 is described.

Be delivered to the amount of the mist of oil of air cleaner 50 from gas distributing chamber 4, changed by the inclination of four stroke engine 1.

Specifically, if can lubricant oil be carried to crankshaft room 5a from gas distributing chamber 4 swimmingly, then the amount being delivered to the mist of oil of air cleaner 50 will tail off.Contrary, if lubricant oil A cannot be carried swimmingly to crankshaft room 5a, then the amount being delivered to the mist of oil of air cleaner 50 will increase.

And the amount being delivered to the mist of oil of this air cleaner 50 changes, the amount of the lubricant oil be separated by oil separator 51 can be made to change.

The amount of the so-called lubricant oil by the separation of this oil separator 51 changes, and refers to the meaning that the amount of the lubricant oil A reclaimed at oil lubrication circulating path changes.

Further, as shown in the first example, when making return flow line 52 be connected with crankshaft room 5a via oil supply gallery 34, coordinating the amount of the lubricant oil being delivered to return flow line 52 from oil separator 51, also can change from the amount of the lubricant oil A of accumulator 7 absorption.

In this way, avoid the amount (the lubricant oil A that can be drawn to from oil supply gallery 34) of the lubricant oil A reclaimed at oil circulation path to change as far as possible, be conducive to stability and the outspent suppression of lubricant oil A of four stroke engine 1.

Therefore, in the second example, as shown in figure 12, return flow line 52 and crankshaft room 5a is connected via put-through channel 46.In other words, return flow line 52 and crankshaft room 5a is not connected via oil supply gallery 34.

By above-mentioned structure, oil supply gallery 34 can be separated with return flow line 52, and then the amount of the lubricant oil A be drawn to via oil supply gallery 34 can be made to stablize.

Above-mentioned structure further can reclaim the lubricant oil after being separated by oil separator 51 expeditiously in oil circulation path.

And, if can in oil separator 51 separation lubrication oil A, thus make lubricant oil A backflow to oil circulation path expeditiously, then isolated lubricant oil A would not be sent to firing chamber, can prevent consuming excessively of lubricant oil A.

In addition, to the open end of the crankshaft room 5a opening of side, return flow line 52, be set to the opening when piston 6 moves near top dead center position towards top dead center, and move period closedown at piston 6 near top dead center position towards lower dead center, more strongly sucking-off can be present in the lubricant oil of return flow line 52 (oil separator 51) by this.

< the 3rd example >

In the second example, as shown in figure 12, return flow line 52 and crankshaft room 5a is connected via put-through channel 46.

But, return flow line 52 and crankshaft room 5a also can not be connected via put-through channel 46.

By above-mentioned structure, the amount being delivered to the lubricant oil A of crankshaft room 5a via oil supply gallery 34 can be made more stable.

Therefore, by above-mentioned structure, circulation oil mass can be made to stablize.

The structure of < example and effect >

Oil separator 51 of the present invention to have from oil circulation path branch formed, for from containing the gas-liquid separation chamber 117 isolating mist of oil the gas blowby of mist of oil.

In addition, gas-liquid separation chamber 117 has the first opening portion 103 importing gas blowby from oil circulation path.

In addition, gas-liquid separation chamber 117 has the second opening portion 105 made from the isolated oil return of gas blowby to oil circulation path, and be vented from gas-liquid separation chamber by the gas blowby being separated mist of oil, and be communicated to the 3rd opening portion 501g of the gas-entered passageway toward firing chamber.

And the first opening portion 103 is formed at first wall 101, the 3rd opening portion 501g is formed at the second wall 501d, in gas-liquid separation chamber 117, between the first opening portion 103 and the 3rd opening portion 501g, is formed with gas-liquid separate component.

Such structure, particularly because this oil separator 51 has gas-liquid separate component 601, thus can suitably isolate aqueous lubricant oil from the gas blowby getting back to air inlet.

In addition, due to suitably lubricant oil can be isolated, thus consuming excessively of lubricant oil can be suppressed.And then discharge environment being had to dysgenic unburned lubricant oil can be suppressed.

Inflow direction and the outflow direction of the gas blowby flowed out from the 3rd opening portion 501g of the gas blowby flowed into from the first opening portion 103 are formed as the position relationship reversed.

Owing to having such structure, oil separator 51 can suitably isolate aqueous lubricant oil from the gas blowby getting back to air inlet.

First opening portion 103 is formed near the central authorities of first wall 101, and the 3rd opening portion 501g is formed in any position in the corner, left and right two of the upper side direction position of the second wall 501d.

Owing to having such structure, the oil separator 51 in the present invention more suitably can carry out gas-liquid separation.

An aspect of gas-liquid separate component 601 is the separation pad 201 near entreating wherein with multiple middle thereof hole 201d.

Owing to having such structure, oil separator 51 can be separated by being separated pad 201 oil that in aqueous lubricant oil, oil droplet is large.

An aspect of gas-liquid separate component 601 of the present invention is in any position in the corner, left and right two of position, be formed with the second opening portion 105 at the lower side of first wall 101, to surround the mode of the first opening portion 103 on first wall 101, the middle thereof hole 201d more lateral position of score from pad 201 is formed with ditch portion 116, form duct-like lubricant oil return passage 115 by ditch portion 116 and separation pad 201, lubricant oil return passage 115 is communicated with the second opening portion 105.

Owing to having such structure, oil separator 51 can make, being separated the aqueous lubricant oil be separated in pad 201, to discharge efficiently from the second opening portion 105.

On the corner being separated pad 201, on the position being formed with the second opening portion 105 of first wall 101, be formed with pad corner through hole 201c.

Owing to having such structure, oil separator 51 can make, by the aqueous lubricant oil be separated after separation pad 201, also can discharge from the second opening portion 105 efficiently.

Gas-liquid separate component 601 is in upper side direction position and the corner location of the opposition side of the 3rd opening portion 501g formation side is formed with the separation bounding means 401 of through hole 401c.

Owing to having such structure, oil separator 51 flows into gas-liquid separation chamber by the gas blowby containing aqueous lubricant oil by the first opening portion 103, and the gas blowby of inflow collides and is separated bounding means 401, thus separable aqueous lubricant oil.

In addition, the through hole 401c being separated bounding means 401 is formed on the position of the opposition side being formed with the 3rd opening portion 501g side, therefore, it is possible to make to be discharged from the 3rd opening portion 501g swimmingly by the gas blowby of this through hole 401c.

The lower side of first wall 101 is formed with the second opening portion 105 in any position in the corner, left and right two of position.

Owing to having such structure, oil separator 51 more positively can discharge aqueous lubricant oil from the second opening portion 105.

Second opening portion 105 is formed at the Power Available Shaft side of the four stroke engine 1 in two corners, left and right, and the 3rd opening portion 501g is formed at the opposition side of the live axle in two corners, left and right.

Owing to having such structure, in upper side direction position and the 3rd opening portion 501g form the corner of the opposition side of side position on the through hole 401c that formed, separate with the position of the 3rd opening portion 501g.

As a result, the gas blowby by through hole 401c successfully can be induced to the 3rd opening portion 501g.

Gas-liquid separate component 601 has mesh shape.

Owing to having such structure, oil separator 51 also can isolate the little mist of oil of oil droplet.

First wall 101 is formed as relative with the second wall 501d.

Owing to having such structure, can fully guarantee the space being formed with gas-liquid separate component.

Gas-liquid separate component 601 have there is multiple middle thereof hole 201d near central authorities separation pad 201, in upper side direction position and the 3rd opening portion 501g form the corner of the opposition side of side position on be formed with the separation bounding means 401 of through hole 401c, and the separating grid 301 of mesh shape, be separated pad 201, be separated bounding means 401 and separating grid 301, from the first opening portion 103 side, it is the arranged in order by being separated pad 201, separating grid 301, separation bounding means 401.

Owing to having such structure, by being separated pad 201, being separated the complementary effect of bounding means 401 and separating grid 301, more effectively mist of oil can be separated.

Gas-liquid separate component 601 has the separation pad 201 near central authorities with multiple middle thereof hole 201d, and in upper side direction position and the 3rd opening portion 501g form the corner of the opposition side of side position on be formed with the separation bounding means 401 of through hole 401c.

In addition, being separated pad 201 and being separated bounding means 401, from the first opening portion 103 side, is by being separated pad 201, being separated the arranged in order of bounding means 401.

Owing to having such structure, by being separated pad 201 and being separated the complementary effect of bounding means 401, can more effectively be separated aqueous lubricant oil.

Gas-liquid separate component 601 has the separation pad 201 near central authorities with multiple middle thereof hole 201d, and the separating grid 301 of mesh shape.

And being separated pad 201 and separating grid 301, from the first opening portion 103 side, is the arranged in order by being separated pad 201 and separating grid 301.

Owing to having such structure, by being separated the complementary effect of pad 201 and separating grid 301, can more effectively be separated aqueous lubricant oil.

Gas-liquid separate component 601 has in upper side direction position and the position in the corner of the opposition side of the 3rd opening portion 501g formation side is formed with the separation bounding means 401 of through hole 401c, and the separating grid 301 of mesh shape.

And, from the first opening portion 103 side, be by separating grid 301, the arranged in order being separated bounding means 401.

Owing to having such structure, by being separated the complementary effect of bounding means 401 and separating grid 301, can more effectively be separated aqueous lubricant oil.

The lubricating fitting of four stroke engine 1 utilizes the pressure change of 5a in the crankshaft room that produces because of the to-and-fro motion of piston 6, lubricant oil A is supplied to the part as oil circulation path and the crankshaft room 5a formed and gas distributing chamber 4, thus lubricate, be provided with in crankshaft room 5a as being communicated with the put-through channel 46 of gas distributing chamber 4 and crankshaft room 5a during negative pressure, the open end to crankshaft room 5a inner opening of put-through channel 46, be set to its opening when piston 6 moves near top dead center position towards top dead center, and move period closedown at piston 6 near top dead center position towards lower dead center.

Owing to having such structure, the lubricant oil A be separated by oil separator 51 can be made efficiently to be recycled to oil circulation path.

The lubricating fitting of four stroke engine 1 utilizes the pressure change in the crankshaft room 5a that produces because of the to-and-fro motion of piston 6, use oil circulation path that lubricant oil A is circulated, thus the lubrication of carrying out each portion, be provided with the return flow line 52 for being communicated with the second opening portion 105 and the crankshaft room 5a of oil separator 51 during negative pressure in crankshaft room 5a, the open end to crankshaft room's inner opening of return flow line 52, be set to its opening when piston 6 moves towards top dead center near top dead center position, and move period closedown at piston 6 near top dead center position towards lower dead center.

Owing to having such structure, the lubricant oil A be separated by oil separator 51 can be made efficiently to be recycled to oil circulation path.

Oil separator 51 is an example of the gas-liquid separation device of four stroke engine in the present invention.

Being separated pad 201, separating grid 301 and being separated bounding means 401 is that one in the present invention in gas-liquid separate component is routine.

Gas-liquid separate component can be made up of separation pad 201, separating grid 301 and separation the whole of bounding means 401, and also can be by wherein any two formed, can also be by wherein any one formed.

Be separated the example that pad 201 is the first pad in the present invention.

Be separated the example that bounding means 401 is the second pad in the present invention.

Separating grid 301 is the example for the net in the present invention.

In addition, an example of the gas-liquid separation chamber in the present invention is gas-liquid separation chamber 117, its space for being formed by the second wall 501d, first wall 101 and the first side 107.That is, as long as be formed in oil circulation path and all can become gas-liquid separation chamber for separating of the space of gas-liquid, there is no particular restriction.

In addition, the invention is not restricted to above mode of execution, the present invention can carry out various structure, the change of formation and modification.

Symbol description

1 ... four stroke engine, 46 ... put-through channel, 50 ... air cleaner, 50c ... gas-liquid separation space, 51 ... oil separator (gas-liquid separation device of four stroke engine), 52 ... return flow line (put-through channel), 54 ... reflux passage, 56 ... flow adjustment passage, 60 ... rod member, 101 ... first wall, 103 ... first opening portion, 105 ... second opening portion, 105a ... chamfered section, 106 ... 4th opening portion, 107 ... first side, 113 ... air purification passage configuration section, 114 ... protuberance, 115 ... lubricant oil return passage, 116 ... ditch portion, 117 ... gas-liquid separation chamber, 121 ... wall portion, 201 ... be separated pad (the first pad), 201c ... pad corner through hole (through hole), 201d ... middle thereof hole (through hole), 301 ... separating grid (net), 301b ... sponge portion, 401 ... be separated bounding means (the second pad), 401c ... through hole, 501 ... separating plate, 501d ... second wall, 501g ... 3rd opening portion, 601 ... gas-liquid separate component

Claims (15)

1. a gas-liquid separation device for four stroke engine, is characterized in that, have from oil circulation path branch formed, for from containing the gas-liquid separation chamber isolating mist of oil the gas blowby of mist of oil,

Above-mentioned gas-liquid separation chamber has:

First opening portion, it imports above-mentioned gas blowby from above-mentioned oil circulation path;

Second opening portion, it makes from the isolated oil return of above-mentioned gas blowby to above-mentioned oil circulation path;

3rd opening portion, the gas blowby being separated mist of oil is vented from above-mentioned gas-liquid separation chamber by it, and is communicated to the gas-entered passageway toward firing chamber,

Above-mentioned first opening portion is formed at first wall,

Above-mentioned 3rd opening portion is formed at the second wall,

In above-mentioned gas-liquid separation chamber, between above-mentioned first opening portion and above-mentioned 3rd opening portion, be formed with gas-liquid separate component,

From inflow direction and the outflow direction of the gas blowby flowed out from above-mentioned 3rd opening portion of the gas blowby of above-mentioned first opening portion inflow, be formed as the position relationship reversed,

Above-mentioned first opening portion is formed near the central authorities of above-mentioned first wall,

Above-mentioned 3rd opening portion is formed at the upper side direction position of above-mentioned second wall, and above-mentioned gas-liquid separate component has first pad near central authorities with multiple through hole, and the net of mesh shape,

Above-mentioned first pad and above-mentioned net, from above-mentioned first opening portion side, are the arranged in order by above-mentioned first pad, above-mentioned net.

2. the gas-liquid separation device of four stroke engine according to claim 1, is characterized in that, above-mentioned gas-liquid separate component is the pad near entreating wherein with multiple middle thereof hole.

3. the gas-liquid separation device of four stroke engine according to claim 2, is characterized in that, is formed with above-mentioned second opening portion at the lower side of above-mentioned first wall in any position in the corner, left and right two of position,

On above-mentioned first wall, to surround the mode of above-mentioned first opening portion, on the position, more lateral, ratio above-mentioned middle thereof hole of above-mentioned pad, be formed with ditch portion,

Form duct-like lubricant oil return passage by above-mentioned ditch portion and above-mentioned pad, above-mentioned lubricant oil return passage is communicated with above-mentioned second opening portion.

4. the gas-liquid separation device of four stroke engine according to claim 3, is characterized in that, on the corner of above-mentioned pad, on the position being formed with above-mentioned second opening portion of above-mentioned first wall, is formed with through hole.

5. the gas-liquid separation device of four stroke engine according to claim 1, is characterized in that, above-mentioned gas-liquid separate component is in upper side direction position and the corner location of the opposition side of above-mentioned 3rd opening portion formation side is formed with the pad of through hole.

6. the gas-liquid separation device of four stroke engine according to claim 5, is characterized in that, is formed with above-mentioned second opening portion at the lower side of above-mentioned first wall in any position in the corner, left and right two of position.

7. the gas-liquid separation device of four stroke engine according to claim 6, it is characterized in that, above-mentioned second opening portion is formed at the Power Available Shaft side of the four stroke engine in two corners, left and right, and above-mentioned 3rd opening portion is formed at the opposition side of the above-mentioned live axle in two corners, left and right.

8. the gas-liquid separation device of four stroke engine according to claim 1, is characterized in that, above-mentioned gas-liquid separate component has mesh shape.

9. the gas-liquid separation device of four stroke engine according to claim 1, is characterized in that, above-mentioned first wall is formed as relative with above-mentioned second wall.

10. the gas-liquid separation device of four stroke engine according to claim 1, it is characterized in that, above-mentioned gas-liquid separate component have there is multiple through hole near central authorities the first pad, in upper side direction position and above-mentioned 3rd opening portion form the corner of the opposition side of side position on be formed with the second pad of through hole, and the net of mesh shape

Above-mentioned first pad, above-mentioned second pad and above-mentioned net, from above-mentioned first opening portion side, are the arranged in order by above-mentioned first pad, above-mentioned net and above-mentioned second pad.

The gas-liquid separation device of 11. four stroke engine according to claim 1, it is characterized in that, above-mentioned gas-liquid separate component has first pad near central authorities with multiple through hole, and in upper side direction position and above-mentioned 3rd opening portion form the corner of the opposition side of side position on be formed with the second pad of through hole

Above-mentioned first pad and above-mentioned second pad, from above-mentioned first opening portion side, are the arranged in order by above-mentioned first pad, above-mentioned second pad.

The gas-liquid separation device of 12. four stroke engine according to claim 1, it is characterized in that, above-mentioned gas-liquid separate component has in upper side direction position and the position in the corner of the opposition side of above-mentioned 3rd opening portion formation side is formed with the second pad of through hole, and the net of mesh shape

Above-mentioned second pad and above-mentioned net, from above-mentioned first opening portion side, are the arranged in order by above-mentioned net, above-mentioned second pad.

The gas-liquid separation device of 13. four stroke engine according to claim 3, it is characterized in that, there is the 4th opening portion made from the isolated oil return of above-mentioned gas blowby to above-mentioned oil circulation path, at the lower side of above-mentioned first wall on the position in the corner, left and right two of position, be formed with above-mentioned second opening portion and above-mentioned 4th opening portion respectively.

The lubricating fitting of 14. 1 kinds of four stroke engine, it utilizes the pressure change in the crankshaft room that produces because of the to-and-fro motion of piston, lubricant oil is supplied to the part as oil circulation path and the above-mentioned crankshaft room that forms and gas distributing chamber, thus lubricates, it is characterized in that

Be provided with for being communicated with the put-through channel of above-mentioned gas distributing chamber and above-mentioned crankshaft room during negative pressure in above-mentioned crankshaft room,

The open end to above-mentioned crankshaft room inner opening of above-mentioned put-through channel, is set to its opening when above-mentioned piston moves near top dead center position towards top dead center, and moves period closedown at above-mentioned piston from above-mentioned near top dead center position towards lower dead center,

Second opening portion of gas-liquid separation device according to claim 1 is connected with above-mentioned put-through channel.

The lubricating fitting of 15. 1 kinds of four stroke engine, the pressure change in the crankshaft room that its utilization produces because of the to-and-fro motion of piston, uses oil circulation path to make lubrication oil circulation, thus carries out, to the lubrication in each portion, it is characterized in that,

Be provided with for being communicated with and the second opening portion of gas-liquid separation device according to claim 1 and the return flow line of above-mentioned crankshaft room during negative pressure in above-mentioned crankshaft room,

The open end to above-mentioned crankshaft room inner opening of above-mentioned return flow line, is set to its opening when above-mentioned piston moves near top dead center position towards top dead center, and moves period closedown at above-mentioned piston from above-mentioned near top dead center position towards lower dead center.