JPH01211622A - V-engine - Google Patents

Abstract

PURPOSE:To reduce the width of an engine without increasing a kind of a cam shaft, by a method wherein the connecting rods of cylinders positioned facing each other are disposed on the same plane, and a single power transmission member is stretched between the cam shaft of the cylinder and crank shaft. CONSTITUTION:Cylinders 3a and 3b are formed so that the suction direction and the exhaust direction of the cylinder 3a are the same as those of the cylinder 3b. Connecting rods 15a and 15b of the cylinders positioned facing each other are disposed on the same plane. A single belt 18 is stretched between each of a shaft 14a of the one cylinder and a cam shaft 14b of the other cylinder and a crank shaft 16. An engine 2 is prevented from expansion in the direction of the crank shaft. This constitution enables the reduction of the width of the engine without increasing a kind of the cam shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a V-type engine used, for example, in a motorcycle.

[Conventional technology]

For example, in V-type engines used in motorcycles, etc., there is a need to reduce the width of the engine in order to install it in the limited space of the vehicle. There is one in which the two are arranged on the same plane.

A power transmission member such as a chain or belt is placed between the camshaft installed above each cylinder and the crankshaft to transmit the rotational force of the crankshaft to each camshaft. The valve is configured to actuate the valve.

[Problem to be solved by the invention]

However, in such a structure, it is necessary to attach each power transmission member to the crankshaft with an offset in the axial direction, and the camshaft to which the outer power transmission member is attached is The camshaft must protrude further to the side of the cylinder than the camshaft. For this reason, there was a problem in that a different type of camshaft was required. The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a V-type engine that allows the width of the engine to be narrowed without increasing the number of types of camshafts.

[Means to solve the problem]

In the V-type engine according to the present invention, each cylinder is formed so that the intake direction and the exhaust direction are the same for each cylinder, the connecting rods of each opposing cylinder are arranged on the same plane, and the connecting rods of one cylinder are arranged on the same plane. A single power transmission member is spanned between the camshaft and the camshaft of the other cylinder and the crankshaft.

[Effect]

In the present invention, each camshaft has the same position of the cam that drives the valve and the same position of the power transmission member.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view taken along the line II in FIG. 2 showing a ■-shaped engine according to the present invention, FIG. 2 is a partial sectional view showing a V-shaped engine, and FIG.
The figure is a left side view showing a motorcycle equipped with a V-type engine, and in FIG. 3, the reference numeral 1 indicates the motorcycle. 2 is an air-cooled V mounted on this motorcycle 1.
The engine has two cylinders 3a and 3b that are inclined in the longitudinal direction of the vehicle body. To be more specific, the front cylinder 3
The cylinder a extends forward from the crankcase 4 in a substantially horizontal direction, and the rear cylinder 3b extends upward from the crankcase 4 in a substantially vertical direction, and a ■-shaped space is formed between these cylinders. There is. 5a.

5b is an exhaust pipe connected to the front side of each cylinder 3a, 3b; 6
a and 6b are carburetors connected to the rear side, and each cylinder 3a
, 3b, the intake direction and the exhaust direction are made equal. The exhaust pipes 5a and 5b pass below the right side of the engine 2 and extend toward the rear of the vehicle body. 7 is a fuel tank disposed to cover the upper part of the engine 2.

Reference numeral 8 designates a vehicle body frame, including a head vibrator 8a, a pair of left and right tank rails 8b connected to the head vibrator 8a and supporting the fuel tank 7, and a pair of left and right tank rails 8b extending downward from the heradopa rib 8a and supporting the engine 2. It is comprised of a down member 8C, a pair of left and right seat pillars 8d connected to the rear part of the tank rail 8b, and the like. Here, the down member 8C and the seat pillar 8d are connected via the crankcase 4, and the engine 2 forms a part of the vehicle body frame 8.

Each cylinder 3a, 3b is constructed by closing the open ends of cylinder bodies 12a, 12b holding pistons lla, Ilb with cylinder heads 13a, 13b, and the cylinder heads 13a, 13b have intake and exhaust valves and rocker arms. Camshafts 14a and 14b, which are driven through them, are rotatably supported. Reference numerals 15a and 15b are connecting rods that connect the pistons lla and Ilb and the crankshaft 16, and these connecting rods 15a and 15b are arranged so that their axes lie on the same plane. That is, the pistons 11a, 11b and the cylinder bodies 12a, 12b are also arranged so that their axes lie on the same plane.

The left end portions of the camshafts 14a and 14b project toward the side of the head, and pulleys 17a and 17b are mounted thereon. 18 is a pulley 17a mounted on these camshafts 14a.
This is a toothed belt as a single power transmission member that is stretched between a pulley 17b mounted on the camshaft 14b and a pulley 19 mounted on the crankshaft 16.

This bell) 18 is a tension pulley 20 arranged on both sides.
a.

20b and tension pulleys 21 disposed between these pulleys in a figure-7 shape.

Note that 1, 22a, and 22b are radiation fins, each of which is provided in the horizontal direction.

In the V-type engine configured in this way, the rotation of the crankshaft 16 is transmitted via the belt 18 to the camshaft 14a,
14b, and the intake and exhaust valves are driven.

Here, by making the intake direction and the exhaust direction the same for each cylinder 3a, 3b and using a single belt 18, the position of the cam that drives the intake and exhaust valves for each camshaft 14a, 14b and the attachment of the belt 18 are determined. Since the contact positions can be made equal, the shapes of the respective camshafts 14a and 14b can be made equal. Therefore, the camshafts 14a, 1
4b can be made common to each cylinder 3'a, 3b.

In addition, the cylinders 3a and 3b can be stacked in the diametrical direction of the crankshaft 16, and the belts 18 are relatively inner than in a structure in which two belts are arranged axially on the crankshaft. Since the engine 2 is disposed in the crankshaft direction, the engine 2 can be prevented from expanding in the crankshaft direction, and the engine width can be narrowed.

In the above embodiment, the front cylinder 3a is made substantially horizontal and the rear cylinder 3b is made substantially vertical. However, the present invention is not limited to this, and for example, the inclination angle of each cylinder may be changed. If they are formed so that they are approximately equal in the longitudinal direction, the direction of the radiation fins can be set in the same direction for each cylinder, and the cylinder head, cylinder, and cylinder body can be made common.

〔Effect of the invention〕

As explained above, according to the present invention, each cylinder is formed so that the intake direction and the exhaust direction are equal to each other, and the connecting rods of the opposing cylinders are disposed on the same plane, and one Since one power transmission member is spanned between the camshaft of one cylinder and the camshaft of the other cylinder and the crankshaft, the cam position and power of each camshaft can be adjusted even if the cylinders are overlapped in the diametrical direction of the crankshaft. The attachment positions of the transmission members can be made equal.

Therefore, the camshaft can be made common to each cylinder while suppressing the expansion of the engine in the crankshaft direction, so the width of the engine can be narrowed without increasing the types of camshafts.

[Brief explanation of the drawing]

FIG. 1 shows 1- in FIG. 2, which shows a ■-type engine according to the present invention.
1-line sectional view, Figure 2 is a partial sectional view showing a V-type engine,
FIG. 3 is a left side view showing a motorcycle equipped with a ■-type engine. 2...Engine, 3a, 3b-...Cylinder, 5a. 5b, ..., exhaust pipe, 6a, 6b---carburizer, 14
a. 14b..., camshaft, 15a, 15b...
, connecting rod, 18...belt. Patent applicant Yamaha Motor Co., Ltd.

Claims (1)

[Claims] In a V-type engine with a camshaft above each cylinder, each cylinder is formed so that the intake direction and exhaust direction are equal to each cylinder, and the connecting rods of each opposing cylinder are arranged on the same plane. At the same time, the V-type engine has a single power transmission member stretched between the camshaft of a cylinder tilted to one side, the camshaft of a cylinder tilted to the other side, and the crankshaft.