JPH02248628A - 2-cycle internal combustion engine - Google Patents

Abstract

PURPOSE: To set the mounting positions of an intake manifold and a carburetor to an engine by respective means for connecting the intake manifold to an engine block, aligning combustion air passages of the manifold and the block, aligning combustion air passages of a carburetor and the manifold, and connecting the carburetor to the manifold. CONSTITUTION: This engine 11 is provided with a means connected to manifold mounting front surfaces 45, 47 and for supplying combustion air to a combustion air passage 68. An intake manifold 115 is connected to the manifold mounting front surfaces 45, 47 by a series of bolts 119, and a combustion air passage 117 is matched to the manifold mounting front surfaces 45, 47 and a combustion air port 69. A series carburetors 125 are connected to the manifold 115, and one carburetor 125 is provided to each combustion air passage 117 of the manifold 115. Accordingly, six carburetors 125 are adopted, and a means is provided for communicating combustion air passages 127 with the combustion air passages 117 of the manifold 115 and fixing the carburetors 125 to the manifold 115.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application) The present invention generally relates to a separate crankcase in which each engine has associated therewith and is defined in part by an engine block member, a crankcase cover member, and a crankshaft. The present invention relates to a two-stroke internal combustion engine of one or more cylinders having a case.

The invention also relates to a structure for conveying combustion air to a separate crankcase. More particularly, the present invention relates to the mounting location of an intake manifold and associated carburetor on an engine.

In addition, the present invention relates to a structure for rotatably supporting a crankshaft relative to an engine and a structure for completing a separate crankcase.

(Conventional technology) Attention is drawn to the following US patents:

Conover 2,224.900 June 6, 1938 Conover 2.227.247 December 4, 1939 Ford et al. 2.334.916 19
May 4, 1942 Kiekhefer 2.549.478
September 5, 1947 Caris et al. 2.983.55
4 May 9, 1961 Weber 3,464,746
June 16, 1967 Onishi 4.185.5
98 January 29, 1980 Matsuo et al. 4.36
8.698 January 18, 1983 Ogawa
4.520.770 June 4, 1985 Hayashi
4,520.771 June 4, 1985 Ogawa
4.651.691 March 24, 1987 (
SUMMARY OF THE INVENTION The present invention provides an engine block that includes an outer surface portion having therein a crankcase-defining cavity that includes a pair of spaced apart bearing surfaces and a pair of spaced apart semi-cylindrical surfaces; a crankshaft including spaced apart bearing portions of the crankshaft and a central portion disposed between the bearing portions and including a pair of spaced apart and enlarged cylindrical surfaces, and a pair of bearing blocks each including a bearing surface;
holding each of the crankshaft bearing portions between a respective one of the bearing surfaces of the engine block and a respective one of the bearing surfaces of the bearing block; a crankcase cover including a mounting surface having a crankcase-defining cavity therein including means for securing the bearing block to the outer surface portion in coplanar relationship with a respective one of; and means for fixedly connecting the mounting surface of the crankcase cover to the outer surface portion of the engine block with each of the semi-cylindrical surfaces of the crankcase cover in a generally coplanar relationship with a respective one of the semi-cylindrical surfaces of the engine block. A two-cycle internal combustion engine is provided.

The invention also includes a first outer surface portion, a second outer surface portion spaced apart from the first portion and having a crankcase-defining cavity therein.
an engine block including an outer surface portion of the engine block and a combustion air passageway extending from the first outer surface portion to the crankcase defining cavity; and an engine block coupled to the first outer surface portion for supplying combustion air to the combustion air passageway. A two-cycle internal combustion engine is provided.

Before describing one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. It is.

The invention is capable of other embodiments and of being practiced and carried out in various ways. Additionally, it is to be understood that the expressions and terminology used herein are for descriptive purposes only and are not to be considered as limiting.

(Example) In the drawing, a two-cycle type V-block internal combustion engine 11 is shown.The engine has left and right cylinder banks 15.
and 17, each cylinder bank containing a suitable number of cylinders 19. In the disclosed construction, each cylinder bank 15 and 17 has three cylinders.
The preferred engine disclosed therefore includes six cylinders 19 (see FIG. 4).

Each cylinder 19 has a cylinder liner 21 therein (see FIGS. 5 and 6).

More particularly, the engine block 13 includes a flat or planar outer mounting surface 41, which outer mounting surface is attached to the central portion 4.
3 and left and right side or manifold mounting portions 45 and 47 respectively disposed on opposite sides of the central portion 43 (
2), the central portion 43 includes a plurality of crankcase-defining cavities 53, one for each of the cylinders 19. Each crankcase-defining cavity 53 is defined in part by a pair of semi-cylindrical walls 55. The crankcase defining cavity 53 cooperates with a crankcase cover and a series of crankshaft discs to form a series of six separate individual crankcases 57, which will be described in more detail below.

The crankcases 57 are arranged in pairs so that in axial order (from top to bottom in FIG. 2) the first and second crankcases 57 are arranged in pairs, such that in axial order (from top to bottom in FIG. 2) the first and second crankcases 57 are arranged in pairs. 59, the third and fourth crankcases 57 constitute a second or central crankcase pair 6I, and the fifth and sixth crankcases 57 constitute a third or outer crankcase pair 6I. Constitute pair 63. Therefore, 2
There are two outer crankcase pairs 59 and 63 and one central crankcase pair 61.

The central portion 43 of the mounting surface 41 also includes a plurality of crankshaft bearing recesses 65 defined in part by respective semi-cylindrical walls 67 (see FIG. 2).

One bearing recess 65 is connected to the outer pair 59 of the crankcase 57.
and 63, and 1
Three bearing recesses 65 are provided in three pairs 59 of the crankcase 57.
．． They are arranged in each of the two spaces between 61 and 63.

Engine block 13 also includes combustion air passages 68 extending from respective crankcases 57 to respective combustion air ports 69 in manifold mounting surface portions 45 and 47 (see FIGS. 2 and 5). In the preferred construction, each of the manifold surface portions 45 and 47 has three combustion air ports 69 (three of the associated banks 15 or 17).
Each crankcase 5 associated with one of the cylinders 19
7).

As already shown, the engine 11 includes a crankshaft 70 (see FIG. 2), and the crankshaft 70 has a crank disk 75.
．． 77 and 79 , the crank discs being spaced apart from each other, cylindrical in shape, having enlarged cylindrical outer surfaces, and a series of crank bins 81 .
and a series of cylindrical bearing parts 83, 85, 87 and 89. Each continuum of crank discs 71
72 or 73 indicates each crank disk 75. which includes crank disks 75 and 77 at both ends and an intermediate crank disk 79.
77 or 79 are arranged in generally coplanar relation to the associated wall 55 (in a plane generally perpendicular to the longitudinal axis of the crankshaft 70). The bearing parts 83 and 89 are arranged axially outward of the crank disc continuum 71 and 73,
The bearing part 85 is arranged between the crank disc series 71 and 720, and the bearing part 87 is arranged between the crank disc series 72 and 73.

Each of the pairs 59, 61 and 63 of the crankcases 57 is of substantially identical construction and is partially defined by an associated series 71, 72 or 73 of crank discs. More particularly, one crankcase 57 in each of the pairs 59, 61 and 63 is defined between the end disc 75 and the intermediate disc 79, and the other crankcase 57 in the six pairs is defined between the end disc 75 and the intermediate disc 79. It is defined between a disk 79 at one end and a disk 77 at the other end.

Means is provided for rotatably supporting the crankshaft 70 on the engine block 13. Although other configurations may be adopted, in the disclosed construction the means are connected to the wall or bearing surface 67 of the crankshaft bearing recess 65 of the engine block 13, to the bearing portions 83, 85, 87 and 89 of the crankshaft 70, and to the engine a bearing block 93 (FIGS. 1 and 6) fixed to the block 13, the bearing block 93 comprising a respective semi-cylindrical bearing surface 95, each bearing a semi-cylindrical bearing surface in an associated bearing cavity 65. Crankshaft bearing portions 83.85.87 and 89 in opposing relation to and associated with surface 67
It is fixed to the engine block 13 in a supporting relationship. Although other constructions may be employed, the disclosed construction uses a suitable bolt 9
7 (FIGS. 1 and 2) passes through the bearing block 93 and is screwed into the engine block 13 to secure the bearing block 93 to the central portion 43 of the engine block surface 41.

Each bearing block 93 and associated bearing surface 67 supports suitable bearing means 99, which bearing means 99 is connected to the crankshaft 7.
85.87 or 89.

As already indicated, the engine 11 includes a crankcase cover or cover member 103 (see FIGS. 1, 2, 5, and 6), and the crankcase cover or cover member 103 is attached to the crankshaft. 7° central portion and a peripheral portion 105 that covers the bearing block 93 and is adapted to engage and mate with the engine block surface 41 (FIGS. 1 and 2).
A crankcase cover space or recess 107 (FIG. 6) is formed inwardly from the periphery 105 including the crankcase discs 75, 77 and 79. The crankcase 5 cooperates with and cooperates with the crankcase defining cavity 53 of the engine block 13.
Define 7. Each crankcase defining cavity 107 has a pair of semi-cylindrical surfaces 109 that cooperate with the associated crank disc.
a respective crankcase 57 defined in part by
Define. Preferably, a suitable seal 110 is attached to the disk 7.
5.77 and 79 and the semi-cylindrical wall 55 of the crankcase-defining cavity 53 of the engine block 13 and the semi-cylindrical wall 109 of the crankcase-defining cavity 107 of the crankcase cover 103.

Means are provided for securing the crankcase cover 103 to the engine block surface 41. Although other structures may be employed, the disclosed structure uses a series of Pol) 111 (second
) is threaded through the periphery 105 of the cover 103 and into the engine block surface 41 so that the cover 103 has its semi-cylindrical surface 109 attached to the semi-cylindrical surface 5 of the engine block 13.
5 and in alignment with the bearing block 93 and in an overlapping relationship with the bearing block 93.

The engine 11 also includes manifold mounting surface portions 45 and 4.
7 with means for supplying combustion air to the combustion air passages 68. In the preferred embodiment, the engine 11 includes three combustion air passages 117 (the fifth An intake manifold 115 (FIGS. 1 and 5) is provided in association with manifold mounting surface portions 45 and 47, respectively. Intake manifold 115 is suitably connected to respective manifold mounting surfaces 45 and 47 by a series of bolts 119 such that combustion air passageways 117 in manifold 115 mate with combustion air ports 69 in manifold mounting surfaces 45 and 47. In the illustrated construction, each intake manifold 115 has three reed boxes 121 (FIG. 5) attached thereto.

It should be understood that other means for supporting lead box 121 may be employed. Each reed box 121 has a respective air passageway 117 in the associated manifold 115.
and extends into each combustion air port 69 of engine block 13 .

A series of vaporizers 125 (FIGS. 1 and 5) are connected to manifold 115;
There is one for each combustion air passage 117 in the. Accordingly, in the preferred disclosed construction, six carburetors 125 are employed, each carburetor 125 including a combustion air passageway 127.

Suitable means are provided for placing the combustion air passages 127 of the carburetor in communication with the combustion air passages 117 of the manifold 115 and for securing the carburetor 125 to the manifold 115. In the illustrated construction, the means consist of a series of screws or bolts 129, although other constructions could be employed.

Various features of the invention are set out in the claims.

[Brief explanation of drawings]

FIG. 1 is a partially sectional top view of an internal combustion engine incorporating the present invention and including an engine block, and FIG. 2 is a top view taken along line 2-2 in FIG.
FIG. 3 is a diagram showing a cutaway view of the crankcase cover, and FIG. 3 is a bottom view of the engine block.
4 is a view taken along line 4-4 of FIG. 3, FIG. 5 is a view taken along line 5-5 of FIG. 2 with parts omitted, and FIG. is a cutaway view taken along line 6-6 of FIG. 1; 11... Internal combustion engine, 13... V type block, 19
...Cylinder, 41...Outer mounting surface, 43...
Center part, 45.47... Manifold mounting part, 5.
3...Crankcase defining cavity, 55...Semi-cylindrical wall, 57...Crankcase, 59.6L 63...
・Crankcase pair, 65...Crankshaft bearing recess,
67... Semi-cylindrical wall, 68-... Combustion air passage, 69
...Combustion air port, 70...Crankshaft, 75.7
7.79...Crank disk, 81...Crank bin, 83.85.87.89...Cylindrical bearing part, 93
... Bearing block, 95 ... Semi-cylindrical bearing surface, 9
9... Bearing means, 103... Crankcase cover or cover member, 107... Crankcase defining cavity or recess, 109... Semi-cylindrical surface, 111... Bolt, 115...・Intake manifold, 117... Combustion air passage, 119... Volt, 125... Carburetor,
127... Combustion air passage, 129... Volt.

Claims (1)

Claims: 1. An engine block including an outer surface portion having therein a crankcase defining cavity including a pair of spaced apart bearing surfaces and a pair of spaced apart semi-cylindrical surfaces, and a pair of spaced apart bearing surfaces. a pair of bearing blocks each including a bearing surface; a pair of bearing blocks each including a bearing surface; each held between a respective one of the bearing surfaces of the engine block and a respective one of the bearing surfaces of the bearing block, and each of the cylindrical surfaces of the crankshaft is held between a respective one of the bearing surfaces of the engine block a crank comprising: means for securing said bearing block to said outer surface portion in coplanar relationship with a respective one of the surfaces; and a mounting surface having a crankcase-defining cavity therein comprising a pair of spaced apart semi-cylindrical surfaces. a case cover, and each of the semi-cylindrical surfaces of the crankcase cover is in a generally coplanar relationship with a respective one of the semi-cylindrical surfaces of the engine block such that the mounting surface of the crankcase cover is connected to the mounting surface of the engine block. and means for fixedly connecting to said outer surface portion. 2. The internal combustion engine of claim 1, wherein the crankcase cover surrounds the bearing block and the central portion of the crankshaft. 3. The internal combustion engine according to claim 1, wherein the crankcase cover is made of plastic. 4. The internal combustion engine according to claim 1, wherein the outer surface portion is planar. 5. a first outer surface portion; a second outer surface portion spaced from the first portion and having a crankcase-defining cavity therein; a cylinder communicating with the crankcase-defining cavity;
and an engine block including a combustion air passage extending from the first outer surface portion to the crankcase defining cavity;
means coupled to the first outer surface portion for supplying combustion air to the combustion air passageway. 6. an intake manifold, said means including a combustion air passage;
means for fixedly connecting the intake manifold to the first outer surface portion of the engine block and aligning the combustion air passage of the manifold with the combustion air passage of the engine block; and a combustion air passage therein. 6. An internal combustion engine as claimed in claim 5, including a carburetor and means for fixedly connecting the carburetor to the manifold with a combustion air passageway of the carburetor in alignment with a combustion air passageway of the intake manifold. . 7. The internal combustion engine of claim 5, wherein the first and second outer surface portions are coplanar.