JPS6079146A - Carburetor arrangement of vertical engine - Google Patents

Abstract

PURPOSE:To reduce the flow path resistance of intake air thus to improve the engine performance by arranging an intake tube of carburetor in the vertical face at the engine side approximately in parallel with a vertical face passing through the center line of cylinder while directing the inlet of said intake tube toward an upper front air-cleaner. CONSTITUTION:Juxtaposed cylinders 1, 2 are inclined such that the upper end will be at the front while an air-cleaner 5 is arranged at the upper front of an integral cylinder head 3 to be shared by both cylinders 1, 2. Here, the center line O10 of an intake tube 10 of a carburetor 8 for front cylinder 1 is in a vertical face at the cylinder side approximately in parallel with a vertical face passing through the center line O1 of cylinder 1 while the inlet section 10a of said tube 10 is directed toward the air-cleaner 5. Consequently, the intake path between the air-cleaner 5 and intake tube 10 can be shortened and made linear resulting in reduction of flow path resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention mainly applies to two-cylinder or four-cylinder motors used in motorcycles.
The present invention relates to a vertically installed cylinder engine in which the engine is inclined so that its upper end is forward, and an air cleaner is disposed above and in front of the engine.

(Prior Art) The intake passage pipe of a carburetor is arranged approximately perpendicularly to the side of the engine with respect to the center line of the cylinder. For this purpose, the rubber duct that connects the carburetor's intake passage pipe and the air cleaner must be made longer, and the rubber duct must also be made thicker (curved) toward the air cleaner side.As a result, the flow path resistance of the rubber duct against intake air becomes thicker. (None, good engine performance cannot be obtained.

(Objective of the invention) By making the intake passage from the intake passage pipe of the carburetor to the air cleaner short (and approximately straight),
The goal is to significantly reduce flow path resistance to intake air and improve engine performance.

(Structure of the Invention) The intake passage pipe of the carburetor is disposed in a vertical plane on the side of the engine that is substantially parallel to the vertical plane passing through the cylinder centerline, and the inlet portion of the intake passage pipe is directed toward the front upper air cleaner side.

(Example) FIG. 1 is a right side view of a two-cylinder vertical engine to which the present invention is applied, and is mounted on, for example, a two-wheeled motor vehicle. In FIG. 1, the cylinders 1.2 are arranged so as to be lined up one after the other, and are inclined so that their upper ends are on the front side.
Also fixed to the upper end is a one-piece cylinder head 3 for both cylinders 1.2. An air cleaner 5 is arranged above and in front of the cylinder head 3. 7 is a clutch cover.

The carburetor 8 for the front cylinder l is equipped with an intake passage pipe 10, and the center line 01o of the intake passage IF10 is aligned with the cylinder 1.
The inlet portion 10a of the intake passage pipe 10 is located in the vertical plane (parallel to the plane of the paper in FIG. 1) on the side of the cylinder, which is approximately parallel to the vertical plane passing through the center line 01 of the cylinder. It faces toward the upper air cleaner 5 side. The intake passage pipe entrance portion 10a is connected to the air cleaner 5 by a short rubber duct 11 that is approximately linear. The outlet of the intake passage pipe 10 is connected to a holder 12, and the holder 12 is connected to the reed valve case 1.
Connected to 3. The reed valve case 13 is fixed to the clutch cover 7 and communicates with the inside of the crankcase (precompression chamber).

The carburetor 8 is, for example, a float type, and includes a piston valve portion 8a, a float chamber 8b, and the like. 14
is a cable that operates the piston within the valve 8a.

FIG. 2 shows a partial view of the section I-II in FIG.
It is clear that the vertical plane passing through (the vertical plane perpendicular to the plane of the paper in Figure 2) is parallel.

16 is a reed valve, which is provided inside the reed valve case 13. 17 is a piston, and 18 is a combustion chamber.

The arrangement and structure of the carburetor ♂, intake passage pipe 102, reed valve case 1, etc. for the rear cylinder 2 in FIG. 1 are the same as those for the front cylinder 1. That is, the vertical plane passing through the center line 08 of the cylinder 2 and the vertical plane passing through the center @ O'so of the carburetor intake passage pipe 10' are approximately parallel to each other, and the inlet portion 1σa of the intake pipe 10' is connected to the front upper air cleaner. Suitable for 5. Also rubber duct 11'
is short (formed);

(Function) Intake air passes through each rubber duct 11.1r from the air cleaner 5, enters the intake passage pipe 1O11♂ of the carburetor 8, male, mixes with fuel in the passage pipe 10.101, passes through the reed valve 16, and is removed from the clutch cover. Enter within 7. Then, from inside the clutch cover 7, the scavenging passages 20 of each cylinder 1, 2 are
(FIG. 2) into the combustion chamber 18 of each cylinder 1.2.

(Another Embodiment) fo This embodiment is applied to a rotary valve type engine instead of the reed valve type engine as in the previous embodiment.

(b) Applicable to engines that intake air-fuel mixture directly from the cylinder.

(c) Applicable to 4-cylinder engines with one pair of cylinders at the front and rear. (c) A structure in which the carburetor is located on a plane slightly similar to the cylinder axis.

(Effects of the invention) The intake passage pipe of the carburetor is arranged in the overlapping plane on the side of the engine, which is approximately parallel to the vertical plane passing through the cylinder centerline, and the inlet of the intake passage pipe is placed toward the front upper air cleaner side. Because the engine is facing toward the engine, the intake passage (rubber duct, etc.) from the air cleaner to the carburetor intake passage pipe is short and nearly straight. This significantly reduces flow resistance in the intake passage and improves engine performance. In addition, the entire engine will be recessed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a right side view of a two-cylinder, two-stroke vertical engine to which the present invention is applied, and FIG. 2 is a sectional view of I[-■ in the lit diagram. 1.2...Cylinder, 5...Excellent air cleaner,
8.8#...Carburetor, 10, lO-...Intake passage pipe, 10a, 1G'! ... Entrance section patent applicant Kawasaki Heavy Industries, Ltd.

Claims (1)

[Claims] In a vertical engine in which the engine is tilted so that its upper end is at the front and an air cleaner is placed above the front of the engine, the intake air of the carburetor is placed in a vertical plane on the side of the engine that is approximately parallel to the vertical plane passing through the cylinder centerline. A carburetor arrangement structure for a vertically mounted engine characterized by a passage pipe being arranged and the inlet of the intake passage pipe facing toward the front upper air cleaner side.