JPS59231129A - Intake apparatus for two-cycle engine - Google Patents

Intake apparatus for two-cycle engine

Info

Publication number
JPS59231129A
JPS59231129A JP10728683A JP10728683A JPS59231129A JP S59231129 A JPS59231129 A JP S59231129A JP 10728683 A JP10728683 A JP 10728683A JP 10728683 A JP10728683 A JP 10728683A JP S59231129 A JPS59231129 A JP S59231129A
Authority
JP
Japan
Prior art keywords
intake passage
cylinder
passage
scavenging
auxiliary
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.)
Granted
Application number
JP10728683A
Other languages
Japanese (ja)
Other versions
JPH0545768B2 (en
Inventor
Akitaka Suzuki
鈴木　章高
Katsumi Kikuoka
菊岡　勝美
Yoshitaka Takabayashi
高林　吉孝
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.)
Yamaha Motor Co Ltd
Original Assignee
Yamaha 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 Yamaha Motor Co Ltd filed Critical Yamaha Motor Co Ltd
Priority to JP10728683A priority Critical patent/JPS59231129A/en
Publication of JPS59231129A publication Critical patent/JPS59231129A/en
Publication of JPH0545768B2 publication Critical patent/JPH0545768B2/ja
Granted legal-status Critical Current

Links

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
    • 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
    • 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
    • F02B61/00—Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing
    • F02B61/02—Adaptations of engines for driving vehicles or for driving propellers; Combinations of engines with gearing for driving cycles

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Supercharger (AREA)

Abstract

PURPOSE:To enable to introduce air-fuel mixture sufficiently from an auxiliary intake passage, by forming an auxiliary intake passage which communicates an intake passage extending from a check valve to an opening in a cylinder with the inside of a crank-case. CONSTITUTION:An auxiliary scavenging passage 21 is formed in a cylinder 2, and it is formed on the imaginary arcuate line of an auxiliary intake passage 17 so as to communicate the scavenging passage 21 with the inside of the cylinder 2. At the time of scavenging operation when a piston 6 is moved downward, scavenging air is supplied into the cylinder 2 via a scavenging passage 14. At the same time, scavenging air is passed through the auxiliary intake passage 17, the intake passage 9 and the auxiliary scavenging passage 21, successively, and also supplied into the cylinder 2.

Description

【発明の詳細な説明】 この発明は、自動二輪車等に設けられる２サイクルエン
ジンの吸気装置に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an intake device for a two-stroke engine installed in a motorcycle or the like.

２サイクルエンジンには、シリンダ内周面に開口する吸
気路が設けられると共に、吸気行程で吸気路とクランク
ケース内とを連通させる連通孔がピストンに形成され、
かつ、混合気をシリンダ内へのみ流入させるリード弁が
吸気路に設けられたいわゆるピストンリードバルブ方式
のものがある。これは、連通孔を介して吸気路からクラ
ンクケース内に混合気を円滑に吸入すると共に、吸気路
から吸入された新気の逆流を防止し、給気比の向上を図
るように構成されたものである。A two-stroke engine is provided with an intake passage that opens on the inner peripheral surface of the cylinder, and a communication hole is formed in the piston to communicate the intake passage with the inside of the crankcase during the intake stroke.
There is also a so-called piston reed valve system in which a reed valve is provided in the intake passage to allow the air-fuel mixture to flow only into the cylinder. This is designed to smoothly draw the air-fuel mixture from the intake passage into the crankcase through the communication hole, and to prevent fresh air drawn from the intake passage from flowing backwards, improving the air supply ratio. It is something.

ところで、上記構成において、給気比の向上のためには
十分な混合気を吸入することが望ましく、そのためには
、連通孔を大径に成形することが考えられる。また、一
方では、ピストンの首振り動を抑制するために、シリン
ダとピストンの摺接面積を所定以上に増大させることが
望まれている。By the way, in the above configuration, it is desirable to suck in sufficient air-fuel mixture in order to improve the air supply ratio, and for this purpose, it is conceivable to form the communication hole to have a large diameter. On the other hand, in order to suppress the swinging movement of the piston, it is desired to increase the sliding contact area between the cylinder and the piston beyond a predetermined value.

この発明は上記のような事情に注目してなされたもので
、混合気の十分な吸入を可能にすると共に、シリンダと
ピストンの摺接面積を十分に確保してピストンの首振り
動を抑制することを目的とする。This invention was made with attention to the above-mentioned circumstances, and it enables sufficient suction of air-fuel mixture and suppresses the oscillation of the piston by ensuring a sufficient sliding contact area between the cylinder and the piston. The purpose is to

上記目的を達成するためのこの発明の特徴とするところ
は、逆止弁からシリンダ内への開口部に至る間の吸気路
とクランクケース内とを連通させる補助吸気路が設けら
れた点である。A feature of the present invention for achieving the above object is that an auxiliary intake passage is provided that communicates the intake passage between the check valve and the opening into the cylinder with the inside of the crankcase. .

以下、この発明の実施例を図に従い説明する。Embodiments of the present invention will be described below with reference to the drawings.

第１図、と第２図は第１実施例を示し、自動二輪車等に
設けられるピストンリードバルブ方式の２サイクルエン
ジン１は、シリンダ２、シリンダへラド３およびクラン
クケース４を有し、シリンダ２に設けられたシリンダラ
イナ５内にピストン６が設けられ、このピストン６と、
クランクケース４内に設けられたクランク軸７とが連結
　８を介して連動連結される。1 and 2 show a first embodiment. A piston reed valve type two-stroke engine 1 installed in a motorcycle or the like has a cylinder 2, a cylinder head 3, and a crankcase 4. A piston 6 is provided in the cylinder liner 5 provided in the cylinder liner 5, and this piston 6 and
A crankshaft 7 provided within the crankcase 4 is interlocked and connected via a connection 8.

上記シリンダ２には、このシリンダ２内に開口する吸気
路９と排気路１１が成形され、吸気行程で、吸気路９内
の混合気をクランクケース４内へ通過させる連通孔１３
がピストン６のスカート部６ａに成形される。また、混
合気をシリンダ２内へのみ流入させる逆止弁たるリード
弁１２が吸気路９に設けられる。一方、シリンダ２には
、クランクケース４からシリンダ２内へ掃気を供給する
掃気路１４．１４が成形される。The cylinder 2 is formed with an intake passage 9 and an exhaust passage 11 that open into the cylinder 2, and a communication hole 13 through which the air-fuel mixture in the intake passage 9 passes into the crankcase 4 during the intake stroke.
is formed on the skirt portion 6a of the piston 6. Further, a reed valve 12 that is a check valve that allows the air-fuel mixture to flow only into the cylinder 2 is provided in the intake passage 9 . On the other hand, a scavenging air passage 14 , 14 is formed in the cylinder 2 to supply scavenging air from the crankcase 4 into the cylinder 2 .

上記シリンダライナ５の下端は、クランクケース４内に
嵌め合わされ、このシリンダライナ５下端には、径方向
対称位置に切欠部１６．１６が形成される。また、リー
ド弁１２からシリンダ２内への開口部に至る間の吸気路
９とクランクケース４内とを連通させる補助吸気路１７
がシリンダ２の内周面２ａを回避して形成される。即ち
、この補助吸気路１７は、吸気路９に開口した第１吸気
路１８と、この第１吸気路１８と各切欠部１６とを連通
させる第２吸気路１９．１９とで構成され、各第２吸気
路１９は、シリンダライナ５下端の外周面に沿ってクラ
ンクケース４を切欠することで形成される。そして、ピ
ストン６が上昇する吸気時には、混合気は、吸気路９か
ら連通孔１３を通過しクランクケース４内に吸入される
と共に、吸気路９から補助吸気路１７を通過してクラン
クケース４内に吸入される（図中実線矢印）。The lower end of the cylinder liner 5 is fitted into the crankcase 4, and cutouts 16.16 are formed in the lower end of the cylinder liner 5 at radially symmetrical positions. Further, an auxiliary intake passage 17 that communicates between the intake passage 9 from the reed valve 12 to the opening into the cylinder 2 and the inside of the crankcase 4 is provided.
is formed avoiding the inner peripheral surface 2a of the cylinder 2. That is, this auxiliary intake passage 17 is composed of a first intake passage 18 that opens into the intake passage 9, and a second intake passage 19, 19 that communicates the first intake passage 18 with each notch 16. The second intake passage 19 is formed by cutting out the crankcase 4 along the outer peripheral surface of the lower end of the cylinder liner 5. During intake when the piston 6 rises, the air-fuel mixture passes through the communication hole 13 from the intake passage 9 and is sucked into the crankcase 4, and also passes from the intake passage 9 through the auxiliary intake passage 17 and enters the crankcase 4. (solid line arrow in the figure).

また、シリンダ２には補助掃気路２１が形成され、この
掃気路２１は、吸気路９とシリンダ２内とを連通させる
ように補助吸気路１７の仮想円弧線上に形成される。そ
して、ピストン６が下降する掃気時には、掃気は、掃気
路１４を通過しシリンダ２内に供給されると共に、補助
吸気路１７、吸気路９および補助掃気路２１を順次通過
してシリンダ２内に供給される。この場合、リード弁１
２により、吸気路９内での掃気の逆流は阻止される（図
中二点鎖線図示）、なお、上記の場合、第２吸気路１９
を、第１吸気路１８からクランクケース４内に至る最短
距離に成形し、これら吸気路１８．１９を補助吸気路１
７′としてもよい。Further, an auxiliary scavenging passage 21 is formed in the cylinder 2, and this scavenging passage 21 is formed on a virtual arc line of the auxiliary intake passage 17 so as to communicate the intake passage 9 with the inside of the cylinder 2. During scavenging when the piston 6 descends, the scavenging air passes through the scavenging passage 14 and is supplied into the cylinder 2, and also sequentially passes through the auxiliary intake passage 17, the intake passage 9, and the auxiliary scavenging passage 21 into the cylinder 2. Supplied. In this case, reed valve 1
2 prevents the backflow of scavenging air in the intake passage 9 (as shown by the two-dot chain line in the figure). In the above case, the second intake passage 19
are formed in the shortest distance from the first intake passage 18 to the inside of the crankcase 4, and these intake passages 18 and 19 are formed as the auxiliary intake passage 1.
It may be set to 7'.

第３図と第４図は第２実施例を示し、シリンダ２下端が
クランクケース４に嵌め合わされ、このシリンダ２下端
外周面の一部が切欠されて第２吸気路１９が成形されて
いる。他の構成は前記実施例と同様である。3 and 4 show a second embodiment, in which the lower end of the cylinder 2 is fitted into the crankcase 4, and a portion of the outer peripheral surface of the lower end of the cylinder 2 is cut out to form a second intake passage 19. The other configurations are the same as those in the previous embodiment.

上記実施例構成によれば、吸気路９とクランクケース４
内とを連通させる補助吸気路１７がシリンダ２の内周面
２ａを回避して形成されたため、シリンダ２の内周面２
ａは連続的な平滑面に保たれることとなる。従って、仮
に、この内周面２ａに補助吸気路１７を開口させるべく
穴あけ加工を施した場合、内周面２ａが不連続となって
熱時間に不均一な変形を増すおそれがあるが、上記構成
によりこの変形は抑制される。According to the configuration of the above embodiment, the intake passage 9 and the crankcase 4
Since the auxiliary intake passage 17 communicating with the inside is formed avoiding the inner circumferential surface 2a of the cylinder 2, the inner circumferential surface 2a of the cylinder 2
a will be maintained as a continuous smooth surface. Therefore, if the inner circumferential surface 2a is drilled to open the auxiliary intake passage 17, the inner circumferential surface 2a may become discontinuous and uneven deformation may increase during heat time. The configuration suppresses this deformation.

この発明によれば、補助吸気路が、吸気路から連通孔を
通りクランクケース内に至る通路とは別に設けられたた
め、補助吸気路により十分な混合気の吸入が可能とされ
ると共に、シリンダとピストンの所定の摺接面積が確保
され、ピストンの首振り動の問題も防止される。According to this invention, since the auxiliary intake passage is provided separately from the passage leading from the intake passage to the inside of the crankcase through the communication hole, the auxiliary intake passage makes it possible to take in sufficient air-fuel mixture, and the cylinder A predetermined sliding contact area of the piston is ensured, and the problem of oscillation of the piston is also prevented.

【図面の簡単な説明】[Brief explanation of the drawing]

図はこの発明の実施例を示し、第１図と第２図はその第
１実施例で、第１図は縦断面図、第２図は第１図のＩＩ
　−ＩＩ線矢視図、第３図と第４図は同第２実施例で、
第３図は縦断面部分図、第４図は第３図のＩＶ−ＩＶ線
矢視図である。 ｌ・・エンジン、２・・シリンダ、９・拳吸気路、１１
・・排気路、１２・・リード弁（逆止弁）、１７・・補
助吸気路。The drawings show an embodiment of the invention, and FIGS. 1 and 2 are the first embodiment, with FIG. 1 being a longitudinal cross-sectional view and FIG. 2 showing II of FIG.
- II line arrow view, FIGS. 3 and 4 are the same second embodiment,
FIG. 3 is a partial vertical cross-sectional view, and FIG. 4 is a view taken along the line IV--IV in FIG. l...Engine, 2...Cylinder, 9.Fist intake path, 11
...Exhaust path, 12..Reed valve (check valve), 17..Auxiliary intake path.

Claims (1)

【特許請求の範囲】 １、シリンダ内に開口する吸気路が設けられると共に、
吸気行程で吸気路とクランクケース内とを連通させる連
通孔がピストンに形成され、かつ。 混合気をシリンダ内へのみ流入させる逆止弁が上記吸気
路に設けられた２サイクルエンジンにおいて、上記逆止
弁からシリンダ内への開口部に至る間の吸気路とクラン
クケース内とを連通させる補助吸気路が設けられたこと
を特徴とする２サイクルエンジンの吸気装置。[Claims] 1. An intake passage opening into the cylinder is provided, and
A communication hole is formed in the piston to communicate the intake passage with the inside of the crankcase during the intake stroke. In a two-stroke engine in which a check valve that allows the air-fuel mixture to flow only into the cylinder is provided in the intake passage, the intake passage between the check valve and the opening into the cylinder communicates with the inside of the crankcase. An intake system for a two-stroke engine, characterized by being provided with an auxiliary intake passage.
JP10728683A 1983-06-15 1983-06-15 Intake apparatus for two-cycle engine Granted JPS59231129A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10728683A JPS59231129A (en) 1983-06-15 1983-06-15 Intake apparatus for two-cycle engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10728683A JPS59231129A (en) 1983-06-15 1983-06-15 Intake apparatus for two-cycle engine

Publications (2)

Publication Number Publication Date
JPS59231129A true JPS59231129A (en) 1984-12-25
JPH0545768B2 JPH0545768B2 (en) 1993-07-12

Family

ID=14455234

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10728683A Granted JPS59231129A (en) 1983-06-15 1983-06-15 Intake apparatus for two-cycle engine

Country Status (1)

Country Link
JP (1) JPS59231129A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63162960U (en) * 1987-04-11 1988-10-25

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5273312U (en) * 1975-11-29 1977-06-01
JPS5567318U (en) * 1978-10-31 1980-05-09

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5273312U (en) * 1975-11-29 1977-06-01
JPS5567318U (en) * 1978-10-31 1980-05-09

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS63162960U (en) * 1987-04-11 1988-10-25

Also Published As

Publication number Publication date
JPH0545768B2 (en) 1993-07-12

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