WO2019187094A1 - Engine - Google Patents

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Publication number
WO2019187094A1
WO2019187094A1 PCT/JP2018/013854 JP2018013854W WO2019187094A1 WO 2019187094 A1 WO2019187094 A1 WO 2019187094A1 JP 2018013854 W JP2018013854 W JP 2018013854W WO 2019187094 A1 WO2019187094 A1 WO 2019187094A1
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WIPO (PCT)
Prior art keywords
crankcase
cylinder
engine
cylinder unit
crankcase body
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PCT/JP2018/013854
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French (fr)
Japanese (ja)
Inventor
壮二 鹿島
寿朗 木浦
広太 ▲徳▼備
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本田技研工業株式会社
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Application filed by 本田技研工業株式会社 filed Critical 本田技研工業株式会社
Priority to PCT/JP2018/013854 priority Critical patent/WO2019187094A1/en
Publication of WO2019187094A1 publication Critical patent/WO2019187094A1/en
Priority to US17/038,821 priority patent/US20210010444A1/en

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    • 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 
    • 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
    • F02F7/00—Casings, e.g. crankcases or frames

Definitions

  • the present invention relates to an engine that can be mounted on a working machine such as a lawn mower or a high pressure washer.
  • an engine includes a crankcase having first and second bearing portions that support both ends of a crankshaft, and a cylinder in which a piston is fitted.
  • a crankcase is constituted by first and second case halves that are joined to each other at a dividing surface that obliquely intersects with the axes of the first and second bearing portions.
  • An engine is described in which a cylinder and a first bearing portion are integrally formed on the body, and a second bearing portion is integrally formed on a second case half.
  • Patent Document 1 when providing a plurality of types of engines with different displacements, it is necessary to prepare a plurality of types of engines corresponding to the displacements, which may significantly increase manufacturing costs. It was.
  • the present invention provides a technology capable of manufacturing engines with different displacements at low cost.
  • crankcase comprising: a bottom portion having a first crankshaft insertion hole; and a cylindrical portion having the bottom portion integrally formed at one end portion in the first direction and having a case opening at the other end portion in the first direction.
  • the body A crankcase cover having a second crankshaft insertion hole and covering the case opening of the crankcase body; A cylinder unit extending in a second direction orthogonal to the first direction from the tubular portion, The cylindrical portion has a cylinder insertion hole that opens in the second direction,
  • the cylinder unit is A cylinder base located inside the crankcase body; A cylinder block located outside the crankcase body, The crankcase cover is detachably attached to the crankcase body, The cylinder unit is detachably attached to the crankcase body.
  • the engine body is divided into the crankcase body, the crankcase cover, and the cylinder unit, it is possible to provide engines with different displacements by simply replacing the cylinder unit.
  • FIG. 6 is a cross-sectional view taken along line AA in FIG. 5. It is the perspective view which looked at the valve mechanism of the engine from the front diagonally upper direction. It is the disassembled perspective view which looked at the valve mechanism of the engine from the front diagonal upper direction.
  • the engine E of the present embodiment is a small general-purpose engine mounted on a walking lawnmower or the like, and constitutes an OHV engine.
  • the axial direction of the crankshaft 2 is the vertical direction (first direction), the direction perpendicular to the vertical direction, and the direction in which the cylinder portion 1b extends is the front-rear direction (second direction).
  • Direction the vertical direction and the direction perpendicular to the front-rear direction are defined as the left-right direction.
  • the front of the engine E is Fr, the rear is Rr, the left is L, the right is R, the upper is U, the lower is D, As shown.
  • the engine E of the present embodiment includes an engine body 1 having a crankcase portion 1a and a cylinder portion 1b, and a crank that is rotatably supported by the crankcase portion 1a in the vertical direction.
  • a piston 4 slidably fitted to the shaft 2 and the cylinder portion 1b and connected to the crankshaft 2 via a connecting rod 3, an intake valve 5, an exhaust valve 6 provided on the head portion 1c of the cylinder portion 1b, and Connected to the spark plug 7, the head cover 8 that covers the head portion 1c of the cylinder portion 1b, the valve mechanism 9 that operates the intake valve 5 and the exhaust valve 6 in accordance with the rotation of the crankshaft 2, and the upper end portion of the crankshaft 2
  • a top cover 12 that covers the top of the engine E, a fuel tank 13 that stores fuel, an air cleaner 14 that purifies air, and a carbure
  • a muffler 16 that exhausts exhaust from the cylinder portion 1b while muting it, and a governor mechanism 17 that automatically opens and closes a throttle valve (not shown) of the carburetor 15 in accordance with the rotational speed of the crankshaft 2 (FIG. 5). 6) and an auto choke mechanism 18 that automatically opens and closes the throttle valve of the carburetor 15 in accordance with the temperature of the engine body 1.
  • the engine body 1 includes a crankcase body 19, a crankcase cover 20, and a cylinder unit 21.
  • the crankcase main body 19 includes a bottom portion 19a and a cylindrical portion 19c having a bottom portion 19a integrally formed at the lower end portion and having a case opening 19b at the upper end portion.
  • a first crankshaft insertion hole 19d through which the lower end side of the crankshaft 2 is inserted is formed at the center of the bottom portion 19a.
  • a hole 19e is formed.
  • reference numeral 19 i denotes a drain opening for discharging oil accumulated in the crankcase portion 1 a.
  • crankcase cover 20 covers the case opening 19 b of the crankcase body 19 and constitutes the crankcase part 1 a of the engine body 1 together with the crankcase body 19.
  • a second crankshaft insertion hole 20 a through which the upper end side of the crankshaft 2 is inserted is formed at the center of the crankcase cover 20.
  • the second bearing 22 provided adjacent to the second crankshaft insertion hole 20 a of the crankcase cover 20 and the first crankshaft insertion hole 19 d provided adjacent to the first crankshaft insertion hole 19 d of the crankcase body 19.
  • the crankshaft 2 is rotatably supported between the bearing 23 and the bearing 23.
  • the crankcase cover 20 is detachably attached to the upper end portion of the crankcase body 19 via a plurality of bolts B1. More specifically, a plurality of bolt insertion holes 20b through which the bolts B1 are inserted from above are formed in the peripheral portion of the crankcase cover 20, while the bolts B1 from above are formed at the upper end of the crankcase body 19. A plurality of bolt fastening holes 19f are formed, and by fastening bolts B1 to the bolt fastening holes 19f via the bolt insertion holes 20b, the crankcase cover 20 is attached to the crankcase body 19 and vice versa. In addition, the crankcase cover 20 can be removed from the crankcase body 19 by releasing the fastening of the bolt B1 from the bolt fastening hole 19f.
  • crankcase body 19 and the crankcase cover 20 as described above, by removing the crankcase cover 20 during the maintenance of the engine E, the inside of the crankcase body 19 can be accessed from above.
  • crankshaft 2 it is possible to easily replace the crankshaft 2 by removing the crankcase cover 20 and extracting the crankshaft 2.
  • the cylinder unit 21 is inserted into the cylinder insertion hole 19e of the crankcase body 19 from the front, and a cylinder base portion 21a located inside the crankcase body 19 and forward from the cylinder base portion 21a.
  • the cylinder base portion 21a and the cylinder portion inner peripheral surface of the cylinder block 21b constitute a cylinder bore 21c that is a sliding surface with the piston 4, and a large number of cooling fins 21d project from the outer peripheral portion of the cylinder block 21b.
  • crankcase main body 19 and the crankcase cover 20 can be shared, and the displacement of the engine can be reduced simply by replacing the cylinder unit 21. It becomes possible to provide different engines E.
  • the cylinder unit 21 is detachably attached to the crankcase body 19 via a plurality of bolts B2 and B3.
  • a plurality of bolt insertion holes (not shown) through which the bolts B2 are inserted from the front are formed at the rear end of the cylinder block 21b, while the bolts B2 are fastened to the front end of the crankcase body 19 from the front.
  • the cylinder unit 21 can be attached to the crankcase body 19 by fastening the bolt B2 to the bolt fastening hole 19g via the bolt insertion hole of the cylinder block 21b.
  • the cylinder unit 21 can be removed from the crankcase body 19 by releasing the fastening of the bolt B2 to the bolt fastening hole 19g.
  • the bolt B3 on the upper end side is attached from the inside of the crankcase body 19.
  • the cylinder unit 21 is fastened. More specifically, the front end portion of the crankcase body 19 is formed with a plurality of bolt insertion holes 19h through which the bolts B3 are inserted from the inside of the crankcase body 19 forward, while the rear of the cylinder block 21b.
  • a plurality of bolt fastening holes (not shown) to which the bolts B3 are fastened from the rear are formed at the end, and the bolts B3 are bolts of the cylinder block 21b through the bolt insertion holes 19h of the crankcase body 19. Fastened to the fastening hole.
  • the external structure of the cylinder block 21b (for example, The cylinder unit 21 can be attached to the crankcase body 19 without interfering with the cooling fins 21d), and the cooling performance of the engine E can be improved.
  • the valve operating mechanism 9 includes a timing gear 24 fixed to the crankshaft 2, a camshaft 25 rotatably supported on the bottom portion 19a of the crankcase main body 19, and a crankcase main body.
  • a pair of lifters 27 supported swingably on the bottom 19a of the 19 via stepped bolts 26, and supported swingably on the front end of the cylinder block 21b via a rocker arm shaft 28, one end of which is an intake valve. 5 or a pair of rocker arms 29 abutting against the front end of the exhaust valve 6 and a push rod accommodating portion 21e formed at the lower part of the cylinder unit 21, and a lifter 27 is connected to the other end of the pair of rocker arms 29, respectively.
  • a pair of push rods 30 and a pair of valve spurs for urging the intake valve 5 and the exhaust valve 6 in the valve closing direction, respectively. It includes a ring 31, a.
  • the camshaft 25 meshes with the timing gear 24, and a cam portion 25a that is rotationally driven by the timing gear 24 at a reduction ratio of 1/2, and a cam that alternately presses the pair of lifters 27 according to the rotational drive of the gear portion 25a.
  • Part 25b When the cam portion 25b pushes the lifter 27, the other end portion of the corresponding rocker arm 29 is pushed via the push rod 30, and the intake valve 5 or the exhaust valve 6 connected to one end portion of the rocker arm 29 opens, When the push of the lifter 27 by the portion 25 b is released, the intake valve 5 or the exhaust valve 6 is closed by the urging force of the valve spring 31.
  • the camshaft 25 of this embodiment is disposed below the cylinder base 21a of the cylinder unit 21.
  • the crankcase cover 20 can be accessed only by removing the crankcase cover 20 during the maintenance of the engine E, without removing the camshaft 25.
  • reference numeral 21g denotes a communication hole provided in the rear wall 21f of the push rod housing portion 21e.
  • the communication hole 21g is provided at a lowermost position when the oil accumulated in the crankcase portion 1a is discharged from the drain opening 19i of the crankcase body 19 to the outside. The accumulated oil is led out to the crankcase part 1a.
  • the vertical direction is described as the first direction, but the first direction may be the horizontal direction or the front-rear direction.
  • a cylinder unit (cylinder unit 21) extending in a second direction orthogonal to the first direction from the cylindrical portion;
  • the cylindrical portion has a cylinder insertion hole (cylinder insertion hole 19e) that opens in the second direction,
  • the cylinder unit is A cylinder base (cylinder base 21a) located inside the crankcase body;
  • the crankcase cover is detachably attached to the
  • crankcase body since the engine is divided into the crankcase body, the crankcase cover, and the cylinder unit, it is possible to provide engines with different displacements by simply replacing the cylinder unit. Moreover, since the crankcase cover is detachably attached to the crankcase body, the inside of the crankcase body can be accessed by removing the crankcase cover during engine maintenance.
  • the cylinder unit can be attached to the crankcase body without interfering with the external structure (for example, cooling fins) of the cylinder block.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Cylinder Crankcases Of Internal Combustion Engines (AREA)

Abstract

An engine (E) is provided with: a crank case body (19); a crank case cover (20) that covers a case opening (19b) of the crank case body (19); and a cylinder unit (21). The crank case cover (20) is detachably attached to the crank case body (19). The cylinder unit (21) is provided with a cylinder base (21a) that is positioned inside the crank case body (19), and a cylinder block (21b) that is positioned outside the crank case body (19), wherein the cylinder unit is detachably attached to the crank case body (19).

Description

エンジンengine
　本発明は、芝刈り機、高圧洗浄機などの作業機に搭載可能なエンジンに関する。 The present invention relates to an engine that can be mounted on a working machine such as a lawn mower or a high pressure washer.
　一般的に、エンジンは、クランクシャフトの両端部を支持する第１及び第２軸受部を有するクランクケースと、ピストンが嵌装されるシリンダと、を備える。例えば、特許文献１には、クランクケースを、第１及び第２軸受部の軸線と斜めに交差する分割面で相互に接合される第１及び第２ケース半体により構成し、第１ケース半体にシリンダ及び第１軸受部を一体に形成するとともに、第２ケース半体に第２軸受部を一体に形成したエンジンが記載されている。 Generally, an engine includes a crankcase having first and second bearing portions that support both ends of a crankshaft, and a cylinder in which a piston is fitted. For example, in Patent Document 1, a crankcase is constituted by first and second case halves that are joined to each other at a dividing surface that obliquely intersects with the axes of the first and second bearing portions. An engine is described in which a cylinder and a first bearing portion are integrally formed on the body, and a second bearing portion is integrally formed on a second case half.
日本国特開２０１７－１６０８３３号公報Japanese Unexamined Patent Publication No. 2017-160833
　しかしながら、特許文献１のエンジン構造では、排気量の異なる複数種類のエンジンを提供する場合、排気量に応じた複数種類のエンジンを用意する必要があるので、製造コストが大幅に上昇する虞があった。 However, in the engine structure disclosed in Patent Document 1, when providing a plurality of types of engines with different displacements, it is necessary to prepare a plurality of types of engines corresponding to the displacements, which may significantly increase manufacturing costs. It was.
　本発明は、排気量の異なるエンジンを安価に製造可能な技術を提供する。 The present invention provides a technology capable of manufacturing engines with different displacements at low cost.
　本発明は、
　第１クランクシャフト挿通孔を有する底部と、第１方向の一端部に前記底部が一体に形成され、前記第１方向の他端部にケース開口部を有する筒状部と、を備える、クランクケース本体と、
　第２クランクシャフト挿通孔を有し、前記クランクケース本体の前記ケース開口部を覆うクランクケースカバーと、
　前記筒状部から、前記第１方向に直交する第２方向に延びるシリンダユニットと、を備え、
　前記筒状部は、前記第２方向に開口するシリンダ挿通孔を有し、
　前記シリンダユニットは、
　前記クランクケース本体の内部に位置するシリンダ基部と、
　前記クランクケース本体の外部に位置するシリンダブロックと、を備え、
　前記クランクケースカバーが前記クランクケース本体に着脱可能に取り付けられ、
　前記シリンダユニットが前記クランクケース本体に着脱可能に取り付けられている。 The present invention
A crankcase comprising: a bottom portion having a first crankshaft insertion hole; and a cylindrical portion having the bottom portion integrally formed at one end portion in the first direction and having a case opening at the other end portion in the first direction. The body,
A crankcase cover having a second crankshaft insertion hole and covering the case opening of the crankcase body;
A cylinder unit extending in a second direction orthogonal to the first direction from the tubular portion,
The cylindrical portion has a cylinder insertion hole that opens in the second direction,
The cylinder unit is
A cylinder base located inside the crankcase body;
A cylinder block located outside the crankcase body,
The crankcase cover is detachably attached to the crankcase body,
The cylinder unit is detachably attached to the crankcase body.
　本発明によれば、エンジン本体が、クランクケース本体と、クランクケースカバーと、シリンダユニットとに分割されているので、シリンダユニットを取り換えるだけで排気量の異なるエンジンを提供することができる。 According to the present invention, since the engine body is divided into the crankcase body, the crankcase cover, and the cylinder unit, it is possible to provide engines with different displacements by simply replacing the cylinder unit.
本発明の一実施形態のエンジンの断面図である。It is sectional drawing of the engine of one Embodiment of this invention. トップカバーを外したエンジンを前方斜め上方から見た斜視図である。It is the perspective view which looked at the engine which removed the top cover from diagonally forward upper direction. エンジンを前方斜め上方から見た分解斜視図である。It is the disassembled perspective view which looked at the engine from front diagonally upward. エンジン本体を前方斜め上方から見た分解斜視図である。It is the disassembled perspective view which looked at the engine body from the diagonally upper front. クランクケースカバーを外したエンジンの平面図である。It is a top view of the engine which removed the crankcase cover. 図５のＡ－Ａ断面図である。FIG. 6 is a cross-sectional view taken along line AA in FIG. 5. エンジンの動弁機構を前方斜め上方から見た斜視図である。It is the perspective view which looked at the valve mechanism of the engine from the front diagonally upper direction. エンジンの動弁機構を前方斜め上方から見た分解斜視図である。It is the disassembled perspective view which looked at the valve mechanism of the engine from the front diagonal upper direction.
　以下、本発明の一実施形態について、図１～図８を参照して説明する。なお、本実施形態のエンジンＥは、歩行型芝刈り機などに搭載される小型汎用エンジンであり、ＯＨＶエンジンを構成している。本明細書等では説明を簡単且つ明確にするためにクランクシャフト２の軸心方向を上下方向（第１方向）、上下方向と直交し、シリンダ部１ｂが延出する方向を前後方向（第２方向）、上下方向及び前後方向と直交する方向を左右方向と定義し、図面には、エンジンＥの前方をＦｒ、後方をＲｒ、左側をＬ、右側をＲ、上方をＵ、下方をＤ、として示す。 Hereinafter, an embodiment of the present invention will be described with reference to FIGS. The engine E of the present embodiment is a small general-purpose engine mounted on a walking lawnmower or the like, and constitutes an OHV engine. In this specification and the like, in order to simplify and clarify the description, the axial direction of the crankshaft 2 is the vertical direction (first direction), the direction perpendicular to the vertical direction, and the direction in which the cylinder portion 1b extends is the front-rear direction (second direction). Direction), the vertical direction and the direction perpendicular to the front-rear direction are defined as the left-right direction. In the drawing, the front of the engine E is Fr, the rear is Rr, the left is L, the right is R, the upper is U, the lower is D, As shown.
　図１～図３に示すように、本実施形態のエンジンＥは、クランクケース部１ａ及びシリンダ部１ｂを有するエンジン本体１と、クランクケース部１ａに上下方向を向いて回転可能に支持されるクランクシャフト２と、シリンダ部１ｂに摺動自在に嵌装され、コンロッド３を介してクランクシャフト２に連結されるピストン４と、シリンダ部１ｂのヘッド部１ｃに設けられる吸気バルブ５、排気バルブ６及び点火プラグ７と、シリンダ部１ｂのヘッド部１ｃを覆うヘッドカバー８と、クランクシャフト２の回転に応じて吸気バルブ５及び排気バルブ６を動作させる動弁機構９と、クランクシャフト２の上端部に連結されるフライホイール１０と、フライホイール１０の上方に配置され、エンジンＥの始動操作を行うリコイルスタータ１１と、エンジンＥの上部を覆うトップカバー１２と、燃料が貯留される燃料タンク１３と、空気を浄化するエアクリーナ１４と、燃料と空気からなる混合気を生成してシリンダ部１ｂ内に供給するキャブレタ１５と、シリンダ部１ｂから排出される排気を消音しながら排出するマフラ１６と、クランクシャフト２の回転数に応じてキャブレタ１５のスロットルバルブ（図示せず）を自動的に開閉するガバナ機構１７（図５、図６参照）と、エンジン本体１の温度に応じてキャブレタ１５のスロットルバルブを自動的に開閉するオートチョーク機構１８と、を備える。 As shown in FIGS. 1 to 3, the engine E of the present embodiment includes an engine body 1 having a crankcase portion 1a and a cylinder portion 1b, and a crank that is rotatably supported by the crankcase portion 1a in the vertical direction. A piston 4 slidably fitted to the shaft 2 and the cylinder portion 1b and connected to the crankshaft 2 via a connecting rod 3, an intake valve 5, an exhaust valve 6 provided on the head portion 1c of the cylinder portion 1b, and Connected to the spark plug 7, the head cover 8 that covers the head portion 1c of the cylinder portion 1b, the valve mechanism 9 that operates the intake valve 5 and the exhaust valve 6 in accordance with the rotation of the crankshaft 2, and the upper end portion of the crankshaft 2 A flywheel 10 to be operated, a recoil starter 11 that is disposed above the flywheel 10 and performs a start operation of the engine E, A top cover 12 that covers the top of the engine E, a fuel tank 13 that stores fuel, an air cleaner 14 that purifies air, and a carburetor 15 that generates an air-fuel mixture consisting of fuel and air and supplies it into the cylinder portion 1b. A muffler 16 that exhausts exhaust from the cylinder portion 1b while muting it, and a governor mechanism 17 that automatically opens and closes a throttle valve (not shown) of the carburetor 15 in accordance with the rotational speed of the crankshaft 2 (FIG. 5). 6) and an auto choke mechanism 18 that automatically opens and closes the throttle valve of the carburetor 15 in accordance with the temperature of the engine body 1.
［エンジン本体］
　図４に示すように、エンジン本体１は、クランクケース本体１９と、クランクケースカバー２０と、シリンダユニット２１と、を備える。 [Engine body]
As shown in FIG. 4, the engine body 1 includes a crankcase body 19, a crankcase cover 20, and a cylinder unit 21.
　図４～図６に示すように、クランクケース本体１９は、底部１９ａと、下端部に底部１９ａが一体に形成され、上端部にケース開口部１９ｂを有する筒状部１９ｃと、を備える。底部１９ａの中心部には、クランクシャフト２の下端側が挿通される第１クランクシャフト挿通孔１９ｄが形成され、筒状部１９ｃの前面部には、シリンダユニット２１のシリンダ基部２１ａが挿通するシリンダ挿通孔１９ｅが形成されている。なお、図４中、符号１９ｉは、クランクケース部１ａの内部に溜まったオイルを排出するドレン開口である。 4 to 6, the crankcase main body 19 includes a bottom portion 19a and a cylindrical portion 19c having a bottom portion 19a integrally formed at the lower end portion and having a case opening 19b at the upper end portion. A first crankshaft insertion hole 19d through which the lower end side of the crankshaft 2 is inserted is formed at the center of the bottom portion 19a. A hole 19e is formed. In FIG. 4, reference numeral 19 i denotes a drain opening for discharging oil accumulated in the crankcase portion 1 a.
　図４に示すように、クランクケースカバー２０は、クランクケース本体１９のケース開口部１９ｂを覆い、クランクケース本体１９と一緒にエンジン本体１のクランクケース部１ａを構成している。クランクケースカバー２０の中心部には、クランクシャフト２の上端側が挿通される第２クランクシャフト挿通孔２０ａが形成されている。図１に戻って、クランクケースカバー２０の第２クランクシャフト挿通孔２０ａに隣接して設けられる第２軸受２２と、クランクケース本体１９の第１クランクシャフト挿通孔１９ｄに隣接して設けられる第１軸受２３と、の間でクランクシャフト２が回転可能に支持される。 As shown in FIG. 4, the crankcase cover 20 covers the case opening 19 b of the crankcase body 19 and constitutes the crankcase part 1 a of the engine body 1 together with the crankcase body 19. A second crankshaft insertion hole 20 a through which the upper end side of the crankshaft 2 is inserted is formed at the center of the crankcase cover 20. Returning to FIG. 1, the second bearing 22 provided adjacent to the second crankshaft insertion hole 20 a of the crankcase cover 20 and the first crankshaft insertion hole 19 d provided adjacent to the first crankshaft insertion hole 19 d of the crankcase body 19. The crankshaft 2 is rotatably supported between the bearing 23 and the bearing 23.
　クランクケースカバー２０は、複数のボルトＢ１を介してクランクケース本体１９の上端部に着脱可能に取り付けられる。具体的に説明すると、クランクケースカバー２０の周縁部には、上方からボルトＢ１が挿通される複数のボルト挿通孔２０ｂが形成される一方、クランクケース本体１９の上端部には、上方からボルトＢ１が締結される複数のボルト締結孔１９ｆが形成されており、ボルト挿通孔２０ｂを介してボルト締結孔１９ｆにボルトＢ１を締結することにより、クランクケース本体１９にクランクケースカバー２０が取り付けられ、逆に、ボルト締結孔１９ｆに対するボルトＢ１の締結を解除することにより、クランクケース本体１９からクランクケースカバー２０を取り外すことが可能になる。 The crankcase cover 20 is detachably attached to the upper end portion of the crankcase body 19 via a plurality of bolts B1. More specifically, a plurality of bolt insertion holes 20b through which the bolts B1 are inserted from above are formed in the peripheral portion of the crankcase cover 20, while the bolts B1 from above are formed at the upper end of the crankcase body 19. A plurality of bolt fastening holes 19f are formed, and by fastening bolts B1 to the bolt fastening holes 19f via the bolt insertion holes 20b, the crankcase cover 20 is attached to the crankcase body 19 and vice versa. In addition, the crankcase cover 20 can be removed from the crankcase body 19 by releasing the fastening of the bolt B1 from the bolt fastening hole 19f.
　このようなクランクケース本体１９及びクランクケースカバー２０によれば、エンジンＥのメンテナンスの際にクランクケースカバー２０を取り外すことで、上部からクランクケース本体１９の内部にアクセスすることができる。特に、クランクシャフト２を取り換える際には、クランクケースカバー２０を取り外し、クランクシャフト２を抜き取ることで、容易にクランクシャフト２を交換することが可能になる。 According to the crankcase body 19 and the crankcase cover 20 as described above, by removing the crankcase cover 20 during the maintenance of the engine E, the inside of the crankcase body 19 can be accessed from above. In particular, when replacing the crankshaft 2, it is possible to easily replace the crankshaft 2 by removing the crankcase cover 20 and extracting the crankshaft 2.
　図４～図６に示すように、シリンダユニット２１は、クランクケース本体１９のシリンダ挿通孔１９ｅに前方から挿通され、クランクケース本体１９の内部に位置するシリンダ基部２１ａと、シリンダ基部２１ａから前方に延出し、クランクケース本体１９の外部に位置するシリンダブロック２１ｂと、を備え、シリンダユニット２１が単体でエンジン本体１のシリンダ部１ｂを構成するとともに、シリンダブロック２１ｂの前端部がヘッド部１ｃを構成している。シリンダ基部２１ａ及びシリンダブロック２１ｂの円筒部内周面は、ピストン４との摺動面であるシリンダボア２１ｃを構成し、シリンダブロック２１ｂの外周部には、多数の冷却フィン２１ｄが突設されている。 As shown in FIGS. 4 to 6, the cylinder unit 21 is inserted into the cylinder insertion hole 19e of the crankcase body 19 from the front, and a cylinder base portion 21a located inside the crankcase body 19 and forward from the cylinder base portion 21a. And a cylinder block 21b positioned outside the crankcase body 19, and the cylinder unit 21 alone constitutes the cylinder portion 1b of the engine body 1, and the front end portion of the cylinder block 21b constitutes the head portion 1c. is doing. The cylinder base portion 21a and the cylinder portion inner peripheral surface of the cylinder block 21b constitute a cylinder bore 21c that is a sliding surface with the piston 4, and a large number of cooling fins 21d project from the outer peripheral portion of the cylinder block 21b.
　このようなシリンダユニット２１によれば、ボア径が異なる複数種類のシリンダユニット２１を用意することにより、クランクケース本体１９及びクランクケースカバー２０を共通化しつつ、シリンダユニット２１を取り換えるだけで排気量の異なるエンジンＥを提供することが可能になる。 According to such a cylinder unit 21, by preparing a plurality of types of cylinder units 21 having different bore diameters, the crankcase main body 19 and the crankcase cover 20 can be shared, and the displacement of the engine can be reduced simply by replacing the cylinder unit 21. It becomes possible to provide different engines E.
　シリンダユニット２１は、複数のボルトＢ２、Ｂ３を介してクランクケース本体１９に着脱可能に取り付けられている。例えば、シリンダブロック２１ｂの後端部に、前方からボルトＢ２が挿通される複数のボルト挿通孔（図示せず）を形成する一方、クランクケース本体１９の前端部に、前方からボルトＢ２が締結される複数のボルト締結孔１９ｇを形成すれば、シリンダブロック２１ｂのボルト挿通孔を介してボルト締結孔１９ｇにボルトＢ２を締結することにより、クランクケース本体１９にシリンダユニット２１を取り付けることができ、逆に、ボルト締結孔１９ｇに対するボルトＢ２の締結を解除することにより、クランクケース本体１９からシリンダユニット２１を取り外すことが可能になる。 The cylinder unit 21 is detachably attached to the crankcase body 19 via a plurality of bolts B2 and B3. For example, a plurality of bolt insertion holes (not shown) through which the bolts B2 are inserted from the front are formed at the rear end of the cylinder block 21b, while the bolts B2 are fastened to the front end of the crankcase body 19 from the front. If the plurality of bolt fastening holes 19g are formed, the cylinder unit 21 can be attached to the crankcase body 19 by fastening the bolt B2 to the bolt fastening hole 19g via the bolt insertion hole of the cylinder block 21b. In addition, the cylinder unit 21 can be removed from the crankcase body 19 by releasing the fastening of the bolt B2 to the bolt fastening hole 19g.
　ただし、本実施形態のエンジン本体１では、複数のボルトＢ２、Ｂ３を介してシリンダユニット２１をクランクケース本体１９に着脱可能に取り付けるにあたり、上端部側のボルトＢ３は、クランクケース本体１９の内部からシリンダユニット２１に締結するようにしている。具体的に説明すると、クランクケース本体１９の前端部には、クランクケース本体１９の内部から前方に向かってボルトＢ３が挿通される複数のボルト挿通孔１９ｈが形成される一方、シリンダブロック２１ｂの後端部には、後方からボルトＢ３が締結される複数のボルト締結孔（図示せず）が形成されており、ボルトＢ３は、クランクケース本体１９のボルト挿通孔１９ｈを介してシリンダブロック２１ｂのボルト締結孔に締結される。 However, in the engine body 1 of the present embodiment, when the cylinder unit 21 is detachably attached to the crankcase body 19 via the plurality of bolts B2 and B3, the bolt B3 on the upper end side is attached from the inside of the crankcase body 19. The cylinder unit 21 is fastened. More specifically, the front end portion of the crankcase body 19 is formed with a plurality of bolt insertion holes 19h through which the bolts B3 are inserted from the inside of the crankcase body 19 forward, while the rear of the cylinder block 21b. A plurality of bolt fastening holes (not shown) to which the bolts B3 are fastened from the rear are formed at the end, and the bolts B3 are bolts of the cylinder block 21b through the bolt insertion holes 19h of the crankcase body 19. Fastened to the fastening hole.
　このようなシリンダユニット２１の取付構造によれば、少なくともシリンダブロック２１ｂの上端部側に、ボルトＢ３を前方から締結させるためのスペースを形成する必要がないので、シリンダブロック２１ｂの外部構造（例えば、冷却フィン２１ｄ）を邪魔することなく、シリンダユニット２１をクランクケース本体１９に取り付けることができ、エンジンＥの冷却性能などを向上させることが可能になる。 According to such a mounting structure of the cylinder unit 21, since it is not necessary to form a space for fastening the bolt B3 from the front at least on the upper end side of the cylinder block 21b, the external structure of the cylinder block 21b (for example, The cylinder unit 21 can be attached to the crankcase body 19 without interfering with the cooling fins 21d), and the cooling performance of the engine E can be improved.
［動弁機構］
　図６～図８に示すように、動弁機構９は、クランクシャフト２に固着されるタイミングギヤ２４と、クランクケース本体１９の底部１９ａに回転可能に支持されるカムシャフト２５と、クランクケース本体１９の底部１９ａに段付ボルト２６を介して揺動可能に支持される一対のリフタ２７と、シリンダブロック２１ｂの前端部にロッカアームシャフト２８を介して揺動可能に支持され、一端部が吸気バルブ５又は排気バルブ６の前端部に当接する一対のロッカアーム２９と、シリンダユニット２１の下部に形成されるプッシュロッド収容部２１ｅに収容され、一対のロッカアーム２９の他端部にそれぞれリフタ２７を連結させる一対のプッシュロッド３０と、吸気バルブ５及び排気バルブ６をそれぞれ閉弁方向に付勢する一対のバルブスプリング３１と、を備える。 [Valve operated mechanism]
As shown in FIGS. 6 to 8, the valve operating mechanism 9 includes a timing gear 24 fixed to the crankshaft 2, a camshaft 25 rotatably supported on the bottom portion 19a of the crankcase main body 19, and a crankcase main body. A pair of lifters 27 supported swingably on the bottom 19a of the 19 via stepped bolts 26, and supported swingably on the front end of the cylinder block 21b via a rocker arm shaft 28, one end of which is an intake valve. 5 or a pair of rocker arms 29 abutting against the front end of the exhaust valve 6 and a push rod accommodating portion 21e formed at the lower part of the cylinder unit 21, and a lifter 27 is connected to the other end of the pair of rocker arms 29, respectively. A pair of push rods 30 and a pair of valve spurs for urging the intake valve 5 and the exhaust valve 6 in the valve closing direction, respectively. It includes a ring 31, a.
　カムシャフト２５は、タイミングギヤ２４と噛み合い、タイミングギヤ２４に２分の１の減速比で回転駆動されるギヤ部２５ａと、ギヤ部２５ａの回転駆動に応じて一対のリフタ２７を交互に押すカム部２５ｂと、を備える。カム部２５ｂがリフタ２７を押すと、プッシュロッド３０を介して対応するロッカアーム２９の他端部が押され、該ロッカアーム２９の一端部に連結される吸気バルブ５又は排気バルブ６が開く一方、カム部２５ｂによるリフタ２７の押しが解除されると、バルブスプリング３１の付勢力で吸気バルブ５又は排気バルブ６が閉じる。 The camshaft 25 meshes with the timing gear 24, and a cam portion 25a that is rotationally driven by the timing gear 24 at a reduction ratio of 1/2, and a cam that alternately presses the pair of lifters 27 according to the rotational drive of the gear portion 25a. Part 25b. When the cam portion 25b pushes the lifter 27, the other end portion of the corresponding rocker arm 29 is pushed via the push rod 30, and the intake valve 5 or the exhaust valve 6 connected to one end portion of the rocker arm 29 opens, When the push of the lifter 27 by the portion 25 b is released, the intake valve 5 or the exhaust valve 6 is closed by the urging force of the valve spring 31.
　本実施形態のカムシャフト２５は、シリンダユニット２１のシリンダ基部２１ａよりも下方に配置されている。このようにカムシャフト２５を配置すると、エンジンＥのメンテナンスの際にクランクケースカバー２０を取り外すだけで、カムシャフト２５を取り外さなくても、上部からクランクケース本体１９の内部にアクセスすることができる。 The camshaft 25 of this embodiment is disposed below the cylinder base 21a of the cylinder unit 21. When the camshaft 25 is arranged in this way, the crankcase cover 20 can be accessed only by removing the crankcase cover 20 during the maintenance of the engine E, without removing the camshaft 25.
　図６中、符号２１ｇは、プッシュロッド収容部２１ｅの後壁２１ｆに設けられた連通孔である。連通孔２１ｇは、クランクケース本体１９のドレン開口１９ｉからクランクケース部１ａの内部に溜まったオイルを外部に排出する際に最下部となる位置に設けられ、ヘッド部１ｃ及びプッシュロッド収容部２１ｅに溜まったオイルをクランクケース部１ａに導出する。 In FIG. 6, reference numeral 21g denotes a communication hole provided in the rear wall 21f of the push rod housing portion 21e. The communication hole 21g is provided at a lowermost position when the oil accumulated in the crankcase portion 1a is discharged from the drain opening 19i of the crankcase body 19 to the outside. The accumulated oil is led out to the crankcase part 1a.
　なお、前述した実施形態は、適宜、変形、改良、等が可能である。例えば、前述した実施形態では、上下方向を第１方向として説明したが、第１方向は左右方向や前後方向としてもよい。 Note that the above-described embodiment can be modified, improved, and the like as appropriate. For example, in the above-described embodiment, the vertical direction is described as the first direction, but the first direction may be the horizontal direction or the front-rear direction.
　本明細書には少なくとも以下の事項が記載されている。なお、括弧内には、上記した実施形態において対応する構成要素等を示しているが、これに限定されるものではない。 This specification includes at least the following items. In addition, although the component etc. which respond | correspond in the above-mentioned embodiment are shown in a parenthesis, it is not limited to this.
　（１）　第１クランクシャフト挿通孔（第１クランクシャフト挿通孔１９ｄ）を有する底部（底部１９ａ）と、第１方向の一端部に前記底部が一体に形成され、前記第１方向の他端部にケース開口部（ケース開口部１９ｂ）を有する筒状部（筒状部１９ｃ）と、を備える、クランクケース本体（クランクケース本体１９）と、
　第２クランクシャフト挿通孔（第２クランクシャフト挿通孔２０ａ）を有し、前記クランクケース本体の前記ケース開口部を覆うクランクケースカバー（クランクケースカバー２０）と、
　前記筒状部から、前記第１方向に直交する第２方向に延びるシリンダユニット（シリンダユニット２１）と、を備え、
　前記筒状部は、前記第２方向に開口するシリンダ挿通孔（シリンダ挿通孔１９ｅ）を有し、
　前記シリンダユニットは、
　前記クランクケース本体の内部に位置するシリンダ基部（シリンダ基部２１ａ）と、
　前記クランクケース本体の外部に位置するシリンダブロック（シリンダブロック２１ｂ）と、を備え、
　前記クランクケースカバーが前記クランクケース本体に着脱可能に取り付けられ、
　前記シリンダユニットが前記クランクケース本体に着脱可能に取り付けられている、エンジン（エンジンＥ）。 (1) A bottom portion (bottom portion 19a) having a first crankshaft insertion hole (first crankshaft insertion hole 19d), and the bottom portion are integrally formed at one end portion in the first direction, and the other end portion in the first direction. A crankcase main body (crankcase main body 19), and a cylindrical portion (cylindrical portion 19c) having a case opening (case opening 19b)
A crankcase cover (crankcase cover 20) having a second crankshaft insertion hole (second crankshaft insertion hole 20a) and covering the case opening of the crankcase body;
A cylinder unit (cylinder unit 21) extending in a second direction orthogonal to the first direction from the cylindrical portion;
The cylindrical portion has a cylinder insertion hole (cylinder insertion hole 19e) that opens in the second direction,
The cylinder unit is
A cylinder base (cylinder base 21a) located inside the crankcase body;
A cylinder block (cylinder block 21b) located outside the crankcase body,
The crankcase cover is detachably attached to the crankcase body,
An engine (engine E) in which the cylinder unit is detachably attached to the crankcase body.
　（１）によれば、エンジンが、クランクケース本体と、クランクケースカバーと、シリンダユニットとに分割されているので、シリンダユニットを取り換えるだけで排気量の異なるエンジンを提供することができる。
　また、クランクケースカバーが、クランクケース本体に着脱可能に取り付けられているので、エンジンのメンテナンスの際にクランクケースカバーを取り外すことで、クランクケース本体の内部にアクセスすることができる。 According to (1), since the engine is divided into the crankcase body, the crankcase cover, and the cylinder unit, it is possible to provide engines with different displacements by simply replacing the cylinder unit.
Moreover, since the crankcase cover is detachably attached to the crankcase body, the inside of the crankcase body can be accessed by removing the crankcase cover during engine maintenance.
　（２）　（１）に記載のエンジンであって、
　前記シリンダユニットは、前記クランクケース本体にボルト（ボルトＢ２、Ｂ３）で締結され、
　前記第１方向の他端部側のボルト（ボルトＢ３）は、前記クランクケース本体の内部から締結される、エンジン。 (2) The engine according to (1),
The cylinder unit is fastened to the crankcase body with bolts (bolts B2, B3),
The engine (bolt B3) on the other end side in the first direction is fastened from the inside of the crankcase body.
　（２）によれば、シリンダブロックの外部構造（例えば、冷却フィン）を邪魔することなく、シリンダユニットをクランクケース本体に取り付けることができる。 According to (2), the cylinder unit can be attached to the crankcase body without interfering with the external structure (for example, cooling fins) of the cylinder block.
Ｅ　エンジン
１９　クランクケース本体
１９ａ　底部
１９ｂ　ケース開口部
１９ｃ　筒状部
１９ｄ　第１クランクシャフト挿通孔
１９ｅ　シリンダ挿通孔
２０　クランクケースカバー
２０ａ　第２クランクシャフト挿通孔
２１　シリンダユニット
２１ａ　シリンダ基部
２１ｂ　シリンダブロック
Ｂ２　ボルト
Ｂ３　ボルト E Engine 19 Crankcase body 19a Bottom portion 19b Case opening 19c Cylindrical portion 19d First crankshaft insertion hole 19e Cylinder insertion hole 20 Crankcase cover 20a Second crankshaft insertion hole 21 Cylinder unit 21a Cylinder base 21b Cylinder block B2 Bolt B3 bolt

Claims (2)

  1. 　第１クランクシャフト挿通孔を有する底部と、第１方向の一端部に前記底部が一体に形成され、前記第１方向の他端部にケース開口部を有する筒状部と、を備える、クランクケース本体と、
    　第２クランクシャフト挿通孔を有し、前記クランクケース本体の前記ケース開口部を覆うクランクケースカバーと、
    　前記筒状部から、前記第１方向に直交する第２方向に延びるシリンダユニットと、を備え、
    　前記筒状部は、前記第２方向に開口するシリンダ挿通孔を有し、
    　前記シリンダユニットは、
    　前記クランクケース本体の内部に位置するシリンダ基部と、
    　前記クランクケース本体の外部に位置するシリンダブロックと、を備え、
    　前記クランクケースカバーが前記クランクケース本体に着脱可能に取り付けられ、
    　前記シリンダユニットが前記クランクケース本体に着脱可能に取り付けられている、エンジン。     A crankcase comprising: a bottom portion having a first crankshaft insertion hole; and a cylindrical portion having the bottom portion integrally formed at one end portion in the first direction and having a case opening at the other end portion in the first direction. The body,
    A crankcase cover having a second crankshaft insertion hole and covering the case opening of the crankcase body;
    A cylinder unit extending in a second direction orthogonal to the first direction from the tubular portion,
    The cylindrical portion has a cylinder insertion hole that opens in the second direction,
    The cylinder unit is
    A cylinder base located inside the crankcase body;
    A cylinder block located outside the crankcase body,
    The crankcase cover is detachably attached to the crankcase body,
    The engine, wherein the cylinder unit is detachably attached to the crankcase body.
  2. 　請求項１に記載のエンジンであって、
    　前記シリンダユニットは、前記クランクケース本体にボルトで締結され、
    　前記第１方向の他端部側のボルトは、前記クランクケース本体の内部から締結される、エンジン。     The engine according to claim 1,
    The cylinder unit is fastened to the crankcase body with a bolt,
    The engine on the other end side in the first direction is fastened from the inside of the crankcase body.
PCT/JP2018/013854 2018-03-30 2018-03-30 Engine WO2019187094A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5759014A (en) * 1980-09-17 1982-04-09 Tecumseh Products Co Internal combustion engine
JPS6226543U (en) * 1985-07-30 1987-02-18
JP2000170515A (en) * 1998-12-10 2000-06-20 Suzuki Motor Corp Decompression device for engine
JP2001115892A (en) * 1999-10-19 2001-04-24 Honda Motor Co Ltd Ohc v-type two-cylinder engine
JP2005351261A (en) * 2004-05-12 2005-12-22 Toyota Motor Corp Internal combustion engine

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5759014A (en) * 1980-09-17 1982-04-09 Tecumseh Products Co Internal combustion engine
JPS6226543U (en) * 1985-07-30 1987-02-18
JP2000170515A (en) * 1998-12-10 2000-06-20 Suzuki Motor Corp Decompression device for engine
JP2001115892A (en) * 1999-10-19 2001-04-24 Honda Motor Co Ltd Ohc v-type two-cylinder engine
JP2005351261A (en) * 2004-05-12 2005-12-22 Toyota Motor Corp Internal combustion engine

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