JPS6148467B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine support structure for a motorcycle equipped with a V-type engine in which cylinders are arranged in the longitudinal direction.

Engines installed in motorcycles are deformed, albeit slightly, by the engine's own heat.
Especially in the case of a V-type engine, the spacing between each cylinder changes due to temperature changes, so when mounting each cylinder so that it is hung on a frame, it is necessary to absorb this change in the spacing between each cylinder. . However, when both cylinders are suspended from the frame via an elastic member, the frame itself must have sufficient rigidity, resulting in an increase in the weight of the vehicle body.

This invention was made in view of the above circumstances, and is applied to motorcycles equipped with V-type engines in which each cylinder is arranged in the front and rear direction.It is highly rigid and suitable for weight reduction, and also prevents thermal deformation of the engine. The purpose is to provide a support structure for an engine that can sufficiently absorb water. To achieve this purpose, a frame is formed to surround the upper and rear parts of the engine, the front cylinder and the rear part of the crankcase are fixed to the frame, and the rear cylinder is supported by the frame via an elastic member. It is configured to do so. The present invention will be explained in detail below based on the drawings.

FIG. 1 is a partially omitted side view of an embodiment of the present invention, FIG. 2 is a view taken in the direction of arrow A showing the support structure for the front cylinder, and FIG. 3 is a partially cross-sectional view of the support structure for the rear cylinder. FIG. In these figures, reference numeral 1 denotes a main frame formed into a substantially box-shaped cross section by joining a pair of left and right metal plate members 1a and 1b. This main frame 1 includes a tank rail portion 2 and a bent portion 3 near its rear end. A steering head pipe 4 is welded to the front end of the tank rail section 2. The tank rail part 2 has a bifurcated shape from the latter half to the upper part of the bent part 3, and a shock absorber loading chamber 5 is formed inside the bifurcated part. That is, each of the metal plate members 1a and 1b is formed so that it bulges out slightly in the width direction of the vehicle body from the rear half of the tank rail portion 2 to the bent portion 3, and that the inner sides thereof are separated from each other to close the inner opening. The inner surface plate 6 is welded as shown in FIG. 3. A shock absorber 7 with an attenuator is loaded in the shock absorber loading chamber 5, and its front end is pivotally supported by the inner surface plate 6. The lower part of the bent part 3 is the left and right metal plate member 1
a and 1b are polymerized and bonded. Metal plate member 1a
A circular opening 8 is formed at a position corresponding to the bent portion 3 . An air purifier (not shown) is disposed on the side of this opening 8. Outside air enters the main frame 1 through the air purifier and the opening 8.
In FIG. 1, reference numerals 9 and 10 indicate intake pipes formed in the tank rail portion 2, and air entering the main frame 1 through the opening 8 is sucked into each cylinder of the engine 20 (described later) through the intake pipes 9 and 10. Ru.

A pair of left and right brackets 11 are firmly fixed so as to hang from the bent portion 3 of the main frame 1, and are substantially a part of the main frame 1. Main frame 1 and bracket 11
is formed so as to surround the upper and rear parts of the engine 20, which will be described later.

Reference numeral 12 denotes a rear arm having a substantially triangular side surface, and this rear arm 12 is pivotally supported between the pair of brackets 11 so as to be rotatable in the vertical direction. This rear arm 12 has a pair of left and right triangular shapes and holds the rear wheel 13 between them. The bottom of this left triangle serves as a propeller shaft case 14, and a gear case 15 is connected to the rear end. A propeller shaft (not shown) is inserted into the propeller shaft case 14, and a large reduction gear (not shown) with which the propeller shaft meshes is housed in the gear case 15. In other words, a shaft drive type drive mechanism is formed. The shock absorber 7 is installed at the top of the rear arm 12.
The rear end is pivoted.

A side plate 16 extending in the longitudinal direction of the vehicle body is firmly fixed to the outside of the bracket 11, and a lower end of a rear stay 17 is fixed to the rear end with a bolt. This rear stay 17 is the seat rail 18
The front end of the seat rail 18 is fixed to the main frame 1 with bolts. Therefore, the rear stay 17 and the seat rail 1
8 can be attached and detached, and by replacing them, vehicles with various specifications can be easily created. Further, since the main frame 1 is manufactured in a completely different process from the rear stay 17 and the seat rail 18, making these parts removable not only facilitates manufacturing but also facilitates transportation of each part.

20 is an air-cooled overhead camshaft V-type engine.
The cylinders 21 and 22 of this engine are arranged so as to be lined up in the longitudinal direction, and the heads of the cylinders 21 and 22 and the rear part of the crankcase 23 are supported by the main frame 1 and the bracket 11. That is, as shown in FIG. 2, a bracket 24 bent into a U-shaped cross section is fixed to the cylinder head of the front cylinder 21 by four bolts 25 installed in the cylinder head. This bracket 2
The opposing pieces 24a and 24b of No. 5 are positioned so as to sandwich the tank rail portion 2 of the main frame 1 at a distance. On the other hand, two collars 26 are fixed to the tank rail portion 2 in the width direction of the vehicle body, and the bracket 24
is firmly fixed by a bolt 27 and a nut 28 passing through this collar 26.

Bracket 2 is installed on the cylinder head of rear cylinder 22.
9 is fixed. The bracket 29 includes a pair of mounting surfaces 29a extending in the width direction of the vehicle body and inclined downward. On the other hand, a ring member 30 facing the mounting surface 29a is fixed to the main frame 1 by a bracket 31 (see FIG. 1). This ring member 30 has a substantially chevron-shaped cross section so that its inner diameter becomes narrower at the center. A rubber elastic member 33 having a collar 32 at its center is attached to the ring member 30. This elastic member 33 is sandwiched between bolts 3 by washers 34 from both sides.
5 passes through the washer 34 and the collar 32, and this bolt 35 further passes through the mounting surface 29a, and a nut 36 is screwed into the tip thereof. Therefore, the bracket 29 of the rear cylinder 22 is able to move slightly due to the elasticity of the elastic member 33.

The rear part of the crankcase 23 of the engine 20 is
It is fixed to a bracket 11 substantially integral with the main frame 1 with two bolts 37.

As a result, the front cylinder 21 and the crankcase 23 form a substantially diamond-shaped loop together with the main frame 1 and the bracket 11, and the rear cylinder 22 crosses this loop. Since the front cylinder 21 and crankcase 23 are fixed to the main frame 1 and the bracket 11, respectively, the engine 20 itself acts as a strength member, increasing the rigidity of the entire vehicle body. Further, since the rear cylinder 22 crosses the substantially rhombic loop so as to divide it into two triangles, the rigidity of the vehicle body is further increased.

Further, due to temperature changes in the engine 20, each part of the engine slightly deforms and expands/contracts. The front cylinder 21 and crankcase 23 are expanded and contracted by the main frame 1,
Together with the bracket 11, this is accommodated by a slight deformation of the entire approximately diamond-shaped loop. The displacement amount of the cylinder head of the rear cylinder 22 is relatively large because the angle between the cylinders 21 and 22 is affected by temperature changes. However, since the rear cylinder 22 and the main frame 1 are connected via the elastic member 33, this displacement of the cylinder head is absorbed by the deformation of the elastic member 33.

In FIG. 1, 38 and 39 are carburetors installed between the intake pipes 9, 10 and the rear and front cylinders 22, 21. 40 is the exhaust pipe of the front cylinder 21,
41 is an exhaust pipe of the rear cylinder 22. The exhaust pipe 41 of the rear cylinder 22 passes between the rear frame 12,
It collects with the exhaust pipe 40 and is guided to the muffler 42.

Further, in FIG. 1, 43 is a fuel tank, and 44 is a seat.

As described above, this invention forms a frame to surround the upper and rear sides of an engine in which each cylinder is arranged in the longitudinal direction, fixes the cylinders and the rear part of the crankcase to the frame, and attaches the rear cylinder to the frame with elastic force. Since it is supported through members, the engine itself works together with the frame to increase the rigidity of the vehicle body. Therefore, since there is no problem even if the rigidity of the frame itself is lowered, the weight of the frame can be reduced. Furthermore, since the head of the rear cylinder can be moved by deforming the elastic member, deformation of the engine due to heat can be sufficiently absorbed.

[Brief explanation of the drawing]

FIG. 1 is a partially omitted side view of an embodiment of the present invention, FIG. 2 is a view taken along arrow A showing the front cylinder installed, and FIG. 3 is a partially sectional view showing the rear cylinder installed. FIG. 1... Main frame, 11... Bracket,
20...V-type engine, 21...front cylinder, 22...
... Rear cylinder, 23 ... Crank case, 33 ... Elastic member.

Claims (1)

[Claims] 1. In a motorcycle equipped with a V-type engine in which cylinders are arranged in the longitudinal direction, a frame is formed to surround the upper and rear sides of the engine,
An engine support structure for a motorcycle, characterized in that a front cylinder and a rear part of the crankcase are fixed to the frame, and a rear cylinder is supported by the frame via an elastic member.