EP1707786A1 - Moteur a combustion interne bicyclique - Google Patents

Moteur a combustion interne bicyclique Download PDF

Info

Publication number
EP1707786A1
EP1707786A1 EP04792479A EP04792479A EP1707786A1 EP 1707786 A1 EP1707786 A1 EP 1707786A1 EP 04792479 A EP04792479 A EP 04792479A EP 04792479 A EP04792479 A EP 04792479A EP 1707786 A1 EP1707786 A1 EP 1707786A1
Authority
EP
European Patent Office
Prior art keywords
cylinder
piston
outer circumferential
circumferential surface
internal combustion
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04792479A
Other languages
German (de)
English (en)
Inventor
Yoshiki c/o DAIHATSU MOTOR CO. LTD. MORINAGA
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Daihatsu Motor Co Ltd
Original Assignee
Daihatsu Motor Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Daihatsu Motor Co Ltd filed Critical Daihatsu Motor Co Ltd
Publication of EP1707786A1 publication Critical patent/EP1707786A1/fr
Withdrawn legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B25/00—Engines characterised by using fresh charge for scavenging cylinders
    • F02B25/14—Engines characterised by using fresh charge for scavenging cylinders using reverse-flow scavenging, e.g. with both outlet and inlet ports arranged near bottom of piston stroke
    • F02B25/16—Engines characterised by using fresh charge for scavenging cylinders using reverse-flow scavenging, e.g. with both outlet and inlet ports arranged near bottom of piston stroke the charge flowing upward essentially along cylinder wall opposite the inlet ports
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/18—Other cylinders
    • F02F1/20—Other cylinders characterised by constructional features providing for lubrication
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F1/00—Cylinders; Cylinder heads 
    • F02F1/18—Other cylinders
    • F02F1/22—Other cylinders characterised by having ports in cylinder wall for scavenging or charging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01M—LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
    • F01M3/00—Lubrication specially adapted for engines with crankcase compression of fuel-air mixture or for other engines in which lubricant is contained in fuel, combustion air, or fuel-air mixture
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
    • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
    • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two

Definitions

  • the present invention relates to a two-cycle internal combustion engine.
  • typical two-cycle internal combustion engines include a uniflow type in which the scavenging of the cylinder is performed utilizing the scavenging flow from a scavenging port provided at a side surface of the cylinder toward an exhaust port provided at the top of the cylinder, and a loop or transverse flow type in which the scavenging of the cylinder is performed utilizing the scavenging flow which travels from a scavenging port provided at a side surface of the cylinder toward the top of the cylinder and then toward an exhaust port similarly provided at the side surface of the cylinder.
  • the scavenging port provided at the side surface of the cylinder opens when the piston comes close to the bottom dead center.
  • both of the scavenging port and the exhaust port provided at the side surface of the cylinder open when the piston comes close to the bottom dead center.
  • the piston has a cylindrical shape whose outer circumferential surface is free from a recess entirely from the upper end to the lower end.
  • the upper end of the outer circumferential surface of the piston is provided with an upper piston ring which is held in close contact with the inner wall of the cylinder, whereas the lower end of the outer circumferential surface is provided with a lower piston ring which is also held in close contact with the inner wall of the cylinder.
  • the scavenging port in the case of the uniflow type
  • the scavenging port and the exhaust port in the case of the loop or transverse flow type
  • Patent Document 1 JP-U-H05-61440
  • the outer circumferential surface regions of the piston on opposite sides of the piston pin are strongly pressed with a large thrust force against the portion of the inner wall of the cylinder where the scavenging port or the exhaust port is provided due to the combustion force in the combustion stroke and the compression force in the compression stroke.
  • a technical object of the present invention is to provide a two-cycle internal combustion engine which is capable of solving these problems.
  • a two-cycle internal combustion engine comprising a cylinder, and a piston which is reciprocally movable in the cylinder and capable of opening or closing an opening of a scavenging port or a exhaust port into the cylinder.
  • the opening of the scavenging port or the discharge port to an inner wall of the cylinder is formed at a portion corresponding to an outer circumferential surface region of the piston at axially opposite ends of a piston pin, and an oil storage space is defined between the inner wall of the cylinder and the outer circumferential surface region of the piston which corresponds to the opening of the scavenging port or the discharge port so that lubricating oil between the inner wall of the cylinder and an outer circumferential surface region of the piston on opposite sides of the piston pin across the axis of the piston pin is pushed out into the oil storage space.
  • the scavenging port or the discharge port includes a plurality of openings to the inner wall of the cylinder.
  • the oil storage space is defined by recessing the outer circumferential surface region of the piston at the axially opposite ends of the piston pin.
  • the outer circumferential surface region of the piston at axially opposite ends of the piston pin is surrounded by two vertical grooves extending axially of the piston, an upper horizontal groove connecting respective upper ends of the vertical grooves to each other, and a lower horizontal groove connecting respective lower ends of the vertical grooves to each other, and the four grooves define the oil storage space.
  • the oil storage space is so designed as to face the scavenging port or the discharge port even when the piston is positioned at a top dead center.
  • the oil storage space is so designed as to face the scavenging port or the discharge port even when the piston is positioned at a top dead center.
  • the size of the outer circumferential surface region of the piston at axially opposite ends of the piston pin is so set that, as viewed in the axial direction of the cylinder, the central angle of a sector defined by connecting the region and the axis of the cylinder lies in the range of 120 to 150 degrees
  • the size of the outer circumferential surface region of the piston on opposite sides of the piston pin across the axis of the piston pin is so set that, as viewed in the axial direction of the cylinder, the central angle of a sector defined by connecting the region and the axis of the cylinder lies in the range of 60 to 30 degrees.
  • the size of the outer circumferential surface region of the piston at axially opposite ends of the piston pin is so set that, as viewed in the axial direction of the cylinder, the central angle of a sector defined by connecting the region and the axis of the cylinder lies in the range of 120 to 150 degrees
  • the size of the outer circumferential surface region of the piston on opposite sides of the piston pin across the axis of the piston pin is so set that, as viewed in the axial direction of the cylinder, the central angle of a sector defined by connecting the region and the axis of the cylinder lies in the range of 60 to 30 degrees.
  • the size of the outer circumferential surface region of the piston at axially opposite ends of the piston pin is so set that, as viewed in the axial direction of the cylinder, the central angle of a sector defined by connecting the region and the axis of the cylinder lies in the range of 120 to 150 degrees
  • the size of the outer circumferential surface region of the piston on opposite sides of the piston pin across the axis of the piston pin is so set that, as viewed in the axial direction of the cylinder, the central angle of a sector defined by connecting the region and the axis of the cylinder lies in the range of 60 to 30 degrees.
  • the engine in the two-cycle internal combustion engine of any one of claims 1, 2, 5, 6, 8 and 9, is a two-cycle diesel engine in which the exhaust port from the cylinder is provided at the top of the cylinder.
  • the engine in the two-cycle internal combustion engine of claim 3, is a two-cycle diesel engine in which the exhaust port from the cylinder is provided at the top of the cylinder.
  • the engine in the two-cycle internal combustion engine of claim 4, is a two-cycle diesel engine in which the exhaust port from the cylinder is provided at the top of the cylinder.
  • the engine in the two-cycle internal combustion engine of claim 7, is a two-cycle diesel engine in which the exhaust port from the cylinder is provided at the top of the cylinder.
  • the opening of the scavenging port or the exhaust port to the inner wall of the cylinder is formed at a portion corresponding to an outer circumferential surface region of the piston at axially opposite ends of the piston pin. Therefore, the outer circumferential surface regions of the piston on opposite sides of the piston pin across the axis of the piston pin are pressed with a large thrust force against the inner wall of the cylinder at portions where the scavenging port or the discharge port is not formed. In this way, the piston is reliably prevented from being pressed with a large thrust force against the inner wall of the cylinder at the portion where the scavenging port or the discharge port is open. Therefore, it is possible to considerably reduce the wearing of the inner wall of the cylinder at the portion where the scavenging port or the exhaust port is open and the piston rings of the piston.
  • an oil storage space is defined between the inner wall of the cylinder and the outer circumferential surface region of the piston which corresponds to the opening of the scavenging port or the discharge port so that lubricating oil between the inner wall of the cylinder and an outer circumferential surface region of the piston on opposite sides of the piston pin across the axis of the piston pin is pushed out into the oil storage space.
  • the lubricating oil is reliably prevented from being pushed toward the scavenging port or the exhaust port due to the strong pressing by the outer circumferential surface regions of the piston on opposite sides of the piston pin across the axis of the piston pin. Therefore, the consumption of the lubricating oil is considerably reduced.
  • the structure according to claim 1 of the present invention is specified.
  • the scavenging or exhaust port includes not a single large opening but a plurality of small openings which open at the inner wall of the cylinder. Therefore, the piston ring of the piston is prevented from being caught on the openings, so that the wearing of the piston ring is effectively reduced.
  • the oil storage space is defined by recessing the outer circumferential surface region of the piston at the axially opposite ends of the piston pin.
  • the outer circumferential surface region of the piston at axially opposite ends of the piston pin is surrounded by two vertical grooves extending axially of the piston, an upper horizontal groove connecting respective upper ends of the vertical grooves to each other, and a lower horizontal groove connecting respective lower ends of the vertical grooves to each other, and the four grooves define the oil storage space.
  • the oil storage space is so designed as to face the scavenging port or the discharge port even when the piston is positioned at a top dead center.
  • the size of the outer circumferential surface region of the piston at axially opposite ends of the piston pin is so set that, as viewed in the axial direction of the cylinder, the central angle of a sector defined by connecting the region and the axis of the cylinder lies in the range of 120 to 150 degrees.
  • the size of the outer circumferential surface region of the piston on opposite sides of the piston pin across the axis of the piston pin is so set that, as viewed in the axial direction of the cylinder, the central angle of a sector defined by connecting the region and the axis of the cylinder lies in the range of 60 to 30 degrees.
  • the lubricating oil is reliably prevented from being pushed toward the scavenging port or the exhaust port due to the strong pressing by the outer circumferential surface regions of the piston on opposite sides of the piston pin across the axis. Therefore, the consumption of the lubricating oil is considerably reduced.
  • the two-cycle internal combustion engine is a two-cycle diesel engine in which the exhaust port from the cylinder is provided at the top of the cylinder. In this instance, since the discharge port is not provided at the inner wall of the cylinder, the consumption of the lubricating oil is small.
  • Figs. 1 and 2 show a first embodiment.
  • the invention is applied to a two-cycle internal combustion engine of the uniflow type.
  • indicated by reference numeral 1 is a cylinder block including a cylinder 2
  • indicated by reference numeral 3 is a cylinder head fastened to the upper surface of the cylinder block 1 so as to close the top of the cylinder 2.
  • a piston 6 connected to a crankshaft 4 via a connecting rod 5 is provided to be reciprocally movable in accordance with the movement of the crankshaft.
  • the cylinder block 1 is formed with a plurality of scavenging ports 7 for supplying compressed intake air into the cylinder 2.
  • the opening of each of the scavenging ports 7 to the inside of the cylinder 2 opens when the piston 6 moves down to come close to the bottom dead center.
  • the cylinder head 3 is formed with an exhaust port 9 provided with an exhaust valve 8 which opens when the piston 6 comes close to the bottom dead center.
  • At the upper end of the outer circumferential surface of the piston 6a ⁇ 6bt least one upper piston ring 10 is provided in close contact with the inner wall of the cylinder 2.
  • At the lower end of the outer circumferential surface of the piston at least one lower piston ring 11 is provided also in close contact with the inner wall of the cylinder 2.
  • the lower piston ring 11 When the piston 6 moves up to the top dead center, the lower piston ring 11 is positioned below the scavenging ports 7. Thus, the lower piston ring 11 prevents each of the scavenging ports 7 from communicating with a crank chamber provided at a lower portion of the cylinder 2.
  • the piston 6 is provided with a piston pin 12 (which extends in parallel with the crank shaft 4, as viewed in the direction of the axis 2a of the cylinder 2).
  • the openings of the scavenging ports 7 to the inside of the cylinder 2 are formed in the inner wall of the cylinder 2 at portions corresponding to regions 6a ⁇ 6b and 6b of the outer circumferential surface of the piston 6 which are on axially opposite ends of the piston pin 12.
  • the openings are formed at portions which do not correspond to the regions 6c and 6d (thrust portion and anti-thrust portion) of the outer circumferential surface of the piston 6 which are on opposite sides of the piston pin 12 across the axis of the piston pin.
  • the openings of the scavenging ports 7 to the inside of the cylinder 2 are oriented in the tangential direction so that the scavenging air from each of the scavenging ports 7 whirls in the cylinder 2.
  • the regions 6a ⁇ 6b and 6b of the outer circumferential surface of the piston 6 between the upper piston ring 10 and the lower piston ring 11 and on axially opposite ends of the piston pin 12 are partially recessed. Between the recessed surface and the inner wall of the cylinder 2 is defined an oil storage space 13, to which the lubricating oil between the inner wall of the cylinder 2 and each of the regions 6c, 6d of the outer circumferential surface of the piston 6 on opposite sides of the piston pin across the axis thereof is pushed out.
  • the opening of each of the scavenging ports 7 faces the oil storage space 13.
  • the oil storage space 13 faces the openings of the scavenging ports even when the piston is positioned at the top dead center.
  • the regions 6c, 6d (thrust portion and anti-thrust portion) of the outer circumferential surface of the piston 6, which are on opposite sides of the piston pin 12 across the axis thereof, are pressed with a large thrust force against the inner wall of the cylinder 2 at portions where the scavenging ports 7 are not formed. Therefore, the piston 6 is reliably prevented from being pressed with a large thrust force against of the inner wall of the cylinder 2 the portions where the scavenging ports 7 open.
  • Fig. 3 shows a second embodiment.
  • the oil storage space 13 is defined by two vertical grooves 13a and 13b extending in the axial direction of the piston 6a ⁇ 6bn upper horizontal groove 13c extending along the lower side of the upper piston ring 10 to connect respective upper ends of the two vertical grooves 13a and 13b, and a lower horizontal groove 13d extending along the upper side of the lower piston ring 11 to connect respective lower ends of the two vertical grooves 13a and 13b.
  • the oil storage space is formed by recessing part of the outer circumferential surface of the piston or by forming grooves at the outer circumferential surface of the piston.
  • the present invention is not limited to such structures, and the oil storage space between the outer circumferential surface of the piston and the inner wall of the cylinder may be formed by other means.
  • the size of the regions 6a - 6b and 6b of the outer circumferential surface of the piston 6 on axially opposite ends of the piston pin 12 is so set that, as viewed in the direction of the axis 2a of the cylinder 2, the central angle ⁇ 1 of a sector defined by connecting each of the regions 6a ⁇ 6b, 6b and the axis 2a of the cylinder 2 lies in the range of 120 to 150 degrees.
  • the size of the regions 6c and 6d of the outer circumferential surface of the piston 6 on opposite sides of the piston pin 12 is so set that, as viewed in the direction of the axis 2a of the cylinder 2, the central angle ⁇ 2 of a sector defined by connecting each of the regions 6c, 6d and the axis 2a of the cylinder 2 lies in the range of 60 to 30 degrees.
  • the present invention is not limited to a two-cycle internal combustion engine of the uniflow type and also applicable to an internal combustion engine of the loop or transverse flow type which does not include an exhaust port provided with an exhaust valve on top of the cylinder but includes a scavenging port and a exhaust port arranged to face each other.
  • the scavenging port and the exhaust port are formed in the inner wall of the cylinder at portions corresponding to axially opposite ends of the piston pin of the piston, respectively, as viewed in the axial direction of the cylinder. Further, in this case, the oil storage space is provided at both of the outer circumferential portions of the piston which correspond to the axially opposite ends of the piston pin.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Pistons, Piston Rings, And Cylinders (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)
EP04792479A 2003-12-16 2004-10-15 Moteur a combustion interne bicyclique Withdrawn EP1707786A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2003417619A JP2005180191A (ja) 2003-12-16 2003-12-16 二サイクル内燃機関
PCT/JP2004/015262 WO2005059345A1 (fr) 2003-12-16 2004-10-15 Moteur a combustion interne bicyclique

Publications (1)

Publication Number Publication Date
EP1707786A1 true EP1707786A1 (fr) 2006-10-04

Family

ID=34697070

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04792479A Withdrawn EP1707786A1 (fr) 2003-12-16 2004-10-15 Moteur a combustion interne bicyclique

Country Status (3)

Country Link
EP (1) EP1707786A1 (fr)
JP (1) JP2005180191A (fr)
WO (1) WO2005059345A1 (fr)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5690591B2 (ja) * 2007-11-08 2015-03-25 トゥー ヘッズ エルエルシー 単ブロック弁なし対向ピストン内燃エンジン

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS586940U (ja) * 1981-07-06 1983-01-17 スズキ株式会社 内燃機関用ピストン
JPH04109252U (ja) * 1991-03-05 1992-09-22 三菱重工業株式会社 ピストン装置

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO2005059345A1 *

Also Published As

Publication number Publication date
JP2005180191A (ja) 2005-07-07
WO2005059345A1 (fr) 2005-06-30

Similar Documents

Publication Publication Date Title
US6862976B2 (en) Monobloc piston
US9303637B2 (en) Connecting rod valve
KR20040041583A (ko) 디젤엔진용 일체형 피스톤
US5186127A (en) Internal combustion engine with offset connecting journal
SE9902113L (sv) Förbränningsmotor
EP0918137A2 (fr) Machine rotative à combustion interne
AU769798B2 (en) Piston and connecting rod retention
US7096843B2 (en) Multicylinder four-cycle combustion engine
CN203948172U (zh) 对置活塞发动机
CN100538055C (zh) 具有不对称销孔槽布置的活塞
US7331276B2 (en) Piston for a two-cycle engine
US9567940B2 (en) Engine arrangement for enhanced cooling
US4282837A (en) Two-cycle diesel engine with piston ring stabilizing accumulator volume
EP1707786A1 (fr) Moteur a combustion interne bicyclique
JPH0526106A (ja) エンジン
JP3890857B2 (ja) ピストンの潤滑構造
JP2768978B2 (ja) 内燃機関用ピストンピンの潤滑構造
JP4133200B2 (ja) 往復動エンジン
US7080610B2 (en) Cooled piston consisting of two parts
JPS5933881Y2 (ja) 内燃機関用ピストン
JP3573036B2 (ja) ピストン構造
JP2580164Y2 (ja) ２サイクルエンジンのピストン
RU2666035C2 (ru) Шатунно-поршневой узел для двигателя внутреннего сгорания
JP3355096B2 (ja) ２サイクルエンジン
JPH11264342A (ja) トランクピストン形ディ―ゼル機関

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20060626

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): DE FR GB

DAX Request for extension of the european patent (deleted)
RBV Designated contracting states (corrected)

Designated state(s): DE FR GB

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20080502