JPH0648362A - Suspension structure for unit swing type engine in motorcycle - Google Patents

Abstract

PURPOSE:To provide the suspension structure of a unit swing type engine in which pressure-insertion components are restricted to one and the precision of the pressure-insertion of a bush or a bearing into this pressure-insertion component can be increased and at the same time number of assembly works can be reduced. CONSTITUTION:A vehicle body side bracket 20 is fitted to a cross pipe 13 that is hung crossways between a pair of the right and left main frames 12 of a motorcycle equipped with a unit swing type engine 15, and an engine side bracket 18 whose body is separate from the engine 15, is fitted to the front of the unit swing type engine 15. By connecting the engine side bracket 18 to the vehicle body side bracket 20 through a link 19, the front of the swing type engine 15 is suspended on the vehicle body side, and at the same time a rubber bush 43 and a bearing 46 to be provided at connection portions between the link 19 and both brackets 20, 18 are inserted into the link 19 under pressure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension structure for a unit swing type engine in a motorcycle.

[0002]

2. Description of the Related Art A small scooter type motorcycle is provided with a unit swing type engine in which an engine and a transmission mechanism are integrated. The front part of the unit swing type engine is provided integrally with a crankcase. The engine side bracket is suspended by connecting via a link to the body side brackets attached to the pair of left and right body frames.

[0003]

However, in the conventional suspension structure, since the engine side bracket is integrally provided on the crankcase of the unit swing type engine, the engine cannot be shared by a plurality of models. There was a problem.

Further, in the conventional suspension structure, since the rubber bushes that absorb the engine vibration and allow the swing of the unit swing type engine are press-fitted on the link side and the engine side, respectively, there are two press-fitted parts. In addition to increasing the number of assembling steps, it was difficult to keep the press-fitting accuracy of the rubber bush high.

The present invention has been made in view of the above problems. The object of the present invention is to limit the number of press-fitting parts to one and reduce the number of assembling steps. (EN) It is an object to provide a suspension structure of a unit swing type engine in a motorcycle that can improve the precision of press fitting of a bearing.

[0006]

In order to achieve the above object, the present invention is to mount a vehicle body side bracket on a vehicle body frame of a motorcycle equipped with a unit swing type engine, and to install the engine in front of the unit swing type engine. A separate engine side bracket is attached, and the front part of the unit swing type engine is suspended on the vehicle body side by connecting the engine side bracket to the vehicle body side bracket via a link, and the link and the both brackets are connected. The feature is that a bearing or a bush provided in the connecting portion is press-fitted into the link.

[0007]

According to the present invention, since the engine-side bracket is constructed separately from the engine, it is possible to share the engine with other models.

Further, since the bush or the bearing is press-fitted into only one part of the link, the number of assembling steps is reduced and the press-fitting accuracy of the bush or bearing is improved.

[0009]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a cutaway side view of a suspension portion at the front of a unit swing type engine, FIG. 2 is a sectional view taken along the line AA of FIG. 1, FIG. 3 is an exploded perspective view of the suspension portion, and FIG. FIG. 5 is a side view of the motorcycle, FIG. 5 is a partial plan view of the motorcycle, and FIG. 6 is a side view of a suspension portion at the rear of the unit swing type engine.

First, a schematic structure of the scooter type motorcycle 1 will be described with reference to FIGS. 4 and 5.

In FIG. 4, reference numeral 2 denotes a head pipe, and a steering shaft 3 is rotatably inserted in the head pipe 2. A steering wheel 4 is attached to an upper portion of the steering shaft 3, and a front wheel 6 is rotatably supported on a lower portion of the steering shaft 3 via a front cushion 5. In FIG. 4, 7 is a front fender and 8 is a front cowl.

From the lower part of the head pipe 2, one down tube 9 and two side tubes 10 extend rearward and downward.

That is, the down tube 9 is provided at the center in the vehicle width direction, and one end (front end) thereof is inserted into and welded to a joint 11 connected to the lower portion of the head pipe 2. The down tube 9 extends obliquely downward from the joint 11, and its rear end is connected to the center of the cross pipe 13 described later in the width direction as shown in FIG.

On the other hand, the two side tubes 10 are
Disposed on both sides of the down tube 9, one end (front end) of each
Is inserted into the side portion of the joint 11 and welded. And each side tube 10 is a joint 1
After extending substantially horizontally from 1 toward the side outward, after being bent at a substantially right angle and extending obliquely forward toward the lower side, after being bent at a substantially right angle again and extending obliquely downward toward the rear side , Is bent at an obtuse angle, extends obliquely upward toward the rear, and the front end of the main frame 12 is inserted and bonded to the rear end thereof.

The pair of left and right main frames 12 extends obliquely upward toward the rear, is bent and rapidly rises, and is then bent again and extends obliquely upward toward the rear. As shown in FIG. 5, a cross pipe 13 is horizontally installed between both main frames 12, and a reinforcing sub-frame 14 is installed between the cross pipe 13 and each main frame 12.

A unit swing type engine 15 is mounted as a drive source on the motorcycle 1, and an engine body 16 of the unit swing type engine 15 has a cylinder 16a and a crankcase 16b which are inclined substantially horizontally. A transmission case 17 is integrally formed on one side of the crankcase 16. One end of the unit swing type engine 15 is connected to the cross pipe 13 through a pair of left and right engine side brackets 18 connected to the lower front end of the crankcase 16b and links 19 pivotally connected to the brackets 18. It is connected to and suspended from the worn body side bracket 20. Further, the other end (rear end) of the unit swing type engine 15 is connected and suspended via a rear cushion 21 to a bracket 22 connected to the main frame 12.

Thus, the unit swing type engine 15
A rear wheel 23 is attached to an output shaft (rear axle) (not shown) that extends horizontally inward from the rear of the transmission case 17, and the upper portion of the rear wheel 23 is covered by a rear fender 24. ing.

An air cleaner 25 is attached to the side of the rear fender 24 and on the transmission case 17 of the unit swing type engine 15. A carburetor 26 is connected to the air cleaner 25, and the carburetor 26 is an intake pipe. It is connected to the intake side of the cylinder 16 a via 27.

On the other hand, as shown in FIG. 4, a storage box 29 for accommodating the helmet 28, a seat 30, and a fuel tank 31 are provided above the unit swing type engine 15, and the fuel tank 31 is the main frame 12 described above.
It is attached to a support frame 32 having a rectangular frame shape that extends rearward from. A license bracket 33 is attached below the fuel tank 31, and the seat 30
The lower part is covered with the exterior cover 34.

The suspension structure of the unit swing type engine 15 according to the present invention will be described in detail with reference to FIGS. 1 to 3.

The engine side bracket 18 is formed separately from the unit swing type engine 15, and a pair of right and left sides are provided as shown in FIG. 3, and both are connected and integrated by a pipe 35. Then, as shown in FIG. 3, each engine-side bracket 18 is attached to the transmission case 17 of the unit swing type engine 15 by two bolts 37 inserted into the bolt holes 36 and long through bolts 39 inserted into the bolt holes 38. It is attached to the lower part of the front end.
An exhaust pipe (not shown) extending from the cylinder 16a passes between the pair of left and right engine-side brackets 18, and the exhaust pipe is protected by the engine-side bracket 18.

Further, as shown in FIG. 3, a pair of left and right links 19 are also provided, and both links 19 are connected and integrated by a pipe 40. Then, cylindrical bosses 41 and 42 are joined to the front and rear ends of each link 19.

On the other hand, the pair of left and right main frames 12
A pair of left and right vehicle body side brackets 20 formed in a channel shape are bonded to a lower portion of the cross pipe 13 which is laterally bridged.

The link 19 is connected to the vehicle body side bracket 20 and the engine side bracket 18 by the following structure.

That is, the rubber bush 43 is press-fitted into the boss 41 connected to the front end portion of each link 19, and the front end portion of the link 19 has the vehicle body side bracket 2 as shown in FIG.
0, and is rotatably supported by being connected to the vehicle body side bracket 20 by a bolt 44 which is inserted into the vehicle body side bracket 20 and the rubber bush 43 from the inside of the vehicle body and a nut 45 which is screwed to the bolt 44. . The rubber bush 43 is formed by baking a ring-shaped rubber on a metal inner / outer tube, and the outer tube is assembled to the link 19 by press-fitting the outer tube into the boss 41.

A bearing 46 is press-fitted into the boss 42 connected to the rear end of each link 19, and the press-fitted bearing 46 is fitted between a pair of left and right engine-side brackets 18 with a sleeve 47. Is passed through. And
The rear end portion (bearing 46) of the link 19 is positioned at a predetermined position on the sleeve 47 by a washer 48 abutting on both surfaces of the link 19 and a circlip 49 fitted to the sleeve 47.

The rear end portion of the link 19 has a long through bolt 51 inserted into the bolt hole 50 formed in the engine side bracket 18 and the sleeve 47, and a nut 52 screwed into the through bolt 51. Is connected to the engine side bracket 18 and is rotatably supported.

In the suspension structure for suspending the front part of the unit swing type engine 15 on the vehicle body as described above, the vehicle body side bracket 20 can be attached to an arbitrary position of the cross pipe 13 which is horizontally extended between the pair of left and right main frames 12. The width dimension of the link 19 whose one end (front end) is connected to the vehicle body side bracket 20 can be set arbitrarily regardless of the distance (width dimension) between the main frames 12, and as a result, the link 19 The degree of freedom of peripheral parts layout is increased, and parts can be shared among various models.

Further, since the engine side bracket 18 is constructed separately from the unit swing type engine 15 and is attached to the crankcase 16b, when the model is changed, the bracket 18 is replaced to change the unit swing type. The engine 15 can be commonly used for each model, and a cost advantage can be obtained.
Also, the cylinder 16a of the crankcase 16b shown in FIG.
There is also an advantage that the machining of the mating surface 16b-1 with is easy.

Further, in this embodiment, the press-fitting component is limited to the link 19 and the rubber bush 43 and the bearing 46 are press-fitted into the link 19, so the number of assembling steps of the rubber bush 43 and the bearing 36 is reduced. The precision of press-fitting into these links 19 is improved as well as the number of links is reduced.

By the way, in the present embodiment, as shown in FIG. 6, the rear cushion 21 is attached to the transmission case 17 via a bracket 53 which is formed separately from the transmission case 17. . In this embodiment, the bracket 53 is made of sheet metal, and the brackets 54, 5 are
5 is connected to the upper rear end of the transmission case 17, and the lower end of the rear cushion 21 is rotatably connected thereto.

If the bracket 53 is formed separately from the transmission case 17 as described above, when the unit swing type engine 15 is shared by a plurality of models, the rear cushion 21 can be replaced by replacing the bracket 53.
The mounting position of can be optimized according to the dimensions of each model.

In the suspension structure according to this embodiment,
Although the case where the rubber bushes 43 and 46 are press-fitted into the link 19 has been described, it goes without saying that the same effect can be obtained when the bearing is press-fitted.

[0035]

As is apparent from the above description, according to the present invention, a vehicle body side bracket is attached to a vehicle body frame of a motorcycle equipped with a unit swing type engine, and the engine is attached to the front part of the unit swing type engine. A separate engine side bracket is attached, and the front part of the unit swing type engine is suspended on the vehicle body side by connecting the engine side bracket to the vehicle body side bracket via a link, and the link and the both brackets are connected. Since the bearing or bush provided in the connecting portion is press-fitted into the link, the number of press-fitting parts is one, and the number of assembling steps can be reduced, and the press-fitting accuracy of the bush or bearing to the press-fitting part can be improved. The effect is obtained.

[Brief description of drawings]

FIG. 1 is a cutaway side view of a suspension unit at the front of a unit swing type engine.

FIG. 2 is a sectional view taken along the line AA of FIG.

FIG. 3 is an exploded perspective view of a suspension unit at the front of the unit swing type engine.

FIG. 4 is a side view of a scooter type motorcycle.

FIG. 5 is a partial plan view of the scooter type motorcycle.

FIG. 6 is a side view of a suspension unit at the rear of the unit swing type engine.

[Explanation of symbols]

 1 scooter type motorcycle 2 head pipe 12 main frame (body frame) 13 cross pipe 15 unit swing engine 18 engine side bracket 19 link 20 body side bracket 43,46 rubber bush

Claims (1)

[Claims] 1. A vehicle body side bracket is attached to a vehicle body frame of a motorcycle equipped with a unit swing type engine, an engine side bracket which is separate from the engine is attached to the front part of the unit swing type engine, and the engine side bracket is attached. The front part of the unit swing type engine is suspended to the vehicle body side by connecting it to the vehicle body side bracket via a link, and the bearing or bush provided at the connecting portion between the link and the both brackets is press-fitted into the link. Suspension structure of unit swing type engine in motorcycle.