JP3643322B2 - Suspension structure of unit swing type engine in motorcycle - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a suspension structure of a unit swing type engine in a motorcycle, and makes it easy and easy to apply the unit swing type engine to motorcycles of different models.
[0002]
[Prior 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 has an engine side bracket provided integrally with a crankcase. It was suspended by connecting via a link to a body side bracket attached to a pair of left and right body frames.
[0003]
[Problems to be solved by the invention]
However, in the conventional suspension structure, since the engine side bracket is provided integrally with the crankcase of the unit swing type engine, there is a problem that the engine cannot be shared by a plurality of models.
In the conventional suspension structure, the rubber bush that absorbs engine vibration and allows the swing of the unit swing type engine is press-fitted into the link side and the engine side, so the press-fitting parts are two parts. 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, and its object is to limit the number of assembling steps by limiting the number of press-fitting parts to one, and press-fitting bushes or bearings into the press-fitted parts. It is possible to improve the accuracy, and to devise the suspension structure so that the unit swing type engine can be easily and easily applied to different types of motorcycles.
[0004]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a motorcycle including a unit swing type engine in which a cylinder projects substantially horizontally from a crankcase, and includes cross pipes horizontally mounted on the left and right main frames of the body frame of the motorcycle. A pair of vehicle body side brackets molded in a channel shape are attached, and an engine side bracket separate from the engine is detachably attached to the lower part of the front end of the crankcase of the unit swing type engine. The front part of the unit swing type engine is suspended on the vehicle body side by connecting to the vehicle body side bracket via a single link, and a rubber bush is press-fitted into the front end connection part of the link, and the rubber bush is press-fitted. In addition, the front end connecting portion is inserted into the channel-shaped body-side bracket. Inclusive order, as well as through the front coupling part rubber bushing bolt in the vehicle body side bracket and the bracket, the bolt by both ends supported on the vehicle body side bracket, the front end coupling portion of the link on the vehicle body side bracket A bearing or a rubber bush is press-fitted to the rear end connecting portion of the link and connected to an engine side bracket, and the rubber bush and the bearing are inside each bracket, and the cylinder of the unit swing type engine Is located inside the left and right main frames.
[0005]
[Action]
In addition, since the press-fitting of the bush or the bearing is performed for one part only of the link, the assembly man-hour is reduced and the press-fitting accuracy of the bush or the bearing is increased.
Furthermore, since the engine side bracket is configured separately from the unit swing type engine and is detachably fixed to the crankcase, the engine side bracket can be selected by selecting the engine side bracket according to the model of the motorcycle. The sub-assembly with the bracket and the unit swing type engine can be applied to different types of motorcycles. Furthermore, since the vehicle body side bracket can be attached to any position of the cross pipe that is horizontally mounted between the left and right main frames, the width dimension of the link connecting one end (front end) to the vehicle body side bracket is It can be arbitrarily set regardless of the distance (width dimension) between the frames, and as a result, the degree of freedom of the component layout around the link is increased and it is possible to cope with a motorcycle of a different model. Therefore, the same unit swing type engine can be shared by different types of motorcycles.
Since the cylinders of the unit swing type engine are inside the left and right main frames, they are protected by the main frames.
[0006]
【Example】
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
The schematic configuration of the scooter type motorcycle 1 is as shown in FIGS.
In FIG. 4, 2 is a head pipe, and a steering shaft 3 is rotatably inserted into the head pipe 2. A steering wheel 4 is attached to the upper part of the steering shaft 3, and a front wheel 6 is rotatably supported via a front cushion 5 at the lower part. In FIG. 4, 7 is a front fender, and 8 is a front cowl.
[0007]
Further, 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 body width direction, and one end (front end) thereof is inserted into and welded to the joint 11 bonded 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 bound to the center in the width direction of a cross pipe 13 to be described later, as shown in FIG.
[0008]
On the other hand, the two side tubes 10 are disposed on both sides of the down tube 9, and one end (front end) of each is inserted into the side portion of the joint 11 and welded. Each side tube 10 extends substantially horizontally from the joint 11 toward the outside of the side, and then bends substantially at a right angle, extends obliquely forward downward, and is bent at a substantially right angle again to the rear. After extending obliquely downward, it is bent at an obtuse angle and extends obliquely upward toward the rear, and the front end portion of the main frame 12 is inserted and bonded to the rear end portion.
[0009]
The pair of left and right main frames 12 extend obliquely upward toward the rear, then bend and rise suddenly, and then bend again and extend obliquely upward toward the rear. As shown in FIG. 5, a cross pipe 13 is installed between the main frames 12, and a reinforcing sub frame 14 is installed between the cross pipe 13 and each main frame 12.
[0010]
By the way, the motorcycle 1 is equipped with a unit swing type engine 15 as a drive source. The engine body 16 of the unit swing type engine 15 has a cylinder 16a and a crankcase 16b inclined substantially horizontally. A transmission case 17 is integrally formed on one side of the case 16b. One end of the unit swing type engine 15 is connected to the cross pipe 13 via a pair of left and right engine side brackets 18 attached to the lower front end of the crankcase 16b, and links 19 pivotally attached to the brackets 18. The vehicle body side bracket 20 is attached and suspended. The other end (rear end) of the unit swing type engine 15 is connected to and suspended from a bracket 22 attached to the main frame 12 via a rear cushion 21.
Thus, a rear wheel 23 is attached to an output shaft (rear axle) (not shown) that extends horizontally inward from the rear portion of the transmission case 17 of the unit swing type engine 15. The upper part of 23 is covered with a rear fender 24.
[0011]
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 connected to an air intake pipe 27. And connected to the intake side of the cylinder 16a.
On the other hand, as shown in FIG. 4, a storage box 29, a seat 30, and a fuel tank 31 in which the helmet 28 is to be stored are provided above the unit swing type engine 15, and the fuel tank 31 extends rearward from the main frame 12. A rectangular frame-like support frame 32 is attached. A license bracket 33 is attached below the fuel tank 31, and a portion below the seat 30 is covered with an exterior cover 34.
[0012]
Here, the suspension structure of the unit swing type engine 15 according to the present invention will be described in detail with reference to FIGS.
The engine side bracket 18 is configured separately from the unit swing type engine 15, and a pair of left and right is provided as shown in FIG. 3, and both are connected and integrated by a pipe 35. As shown in FIG. 3, each engine-side bracket 18 is connected 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 bound to the lower front end. An exhaust pipe (not shown) led out from the cylinder 16 a passes between the pair of left and right engine side brackets 18, and the exhaust pipe is protected by the engine side bracket 18.
[0013]
As shown in FIG. 3, the link 19 is provided in a pair of left and right, and both the links 19 are connected and integrated by a pipe 40. Further, cylindrical bosses 41 and 42 are bound to the front and rear ends of each link 19.
On the other hand, a pair of left and right vehicle body side brackets 20 formed in a channel shape are bonded to the lower part of the cross pipe 13 that is horizontally mounted between the pair of left and right main frames 12.
Thus, the link 19 is connected to the vehicle body side bracket 20 and the engine side bracket 18 by the following structure. That is, a 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 is fitted into the vehicle body side bracket 20 as shown in FIG. 20 and the rubber bush 43 are connected to the vehicle body side bracket 20 by a bolt 44 inserted from the inside of the vehicle body and a nut 45 screwed to the bolt 44, and supported rotatably. The rubber bush 43 is formed by baking a ring-shaped rubber on a metallic inner and outer cylindrical tube, and this is assembled to the link 19 by pressing the outer cylinder into the boss 41.
[0014]
A bearing 46 is press-fitted into the boss 42 attached to the rear end portion of each link 19, and a sleeve 47 installed between the pair of left and right engine side brackets 18 is passed through the press-fitted bearing 46. The The rear end portion (bearing 46) of the link 19 is positioned at a predetermined position on the sleeve 47 by a washer 48 that abuts on both sides of the link 19 and a circlip 49 that is fitted to the sleeve 47.
Thus, the rear end portion of the link 19 is connected to the engine side by a bolt hole 50 formed in the engine side bracket 18 and a long through bolt 51 inserted into the sleeve 47 and a nut 52 screwed to the through bolt 51. It is connected to the bracket 18 and is rotatably supported.
[0015]
In the suspension structure of the front part of the unit swing type engine 15 described above for the vehicle body, the vehicle body side bracket 20 can be attached to any position of the cross pipe 13 that is horizontally mounted 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 side bracket 20 can be arbitrarily set regardless of the distance (width dimension) between the main frames 12, and as a result, the components around the link 19 As the degree of freedom in layout increases, it is possible to share components across multiple models.
[0016]
Further, since the engine side bracket 18 is configured separately from the unit swing type engine 15 and is attached to the crankcase 16b, the unit swing type engine 15 can be changed by replacing the bracket 18 when changing the model. It is possible to share it for each model, and a cost advantage can be obtained. Moreover, the merit that machining of the mating surface 16b-1 with the cylinder 16a of the crankcase 16b shown in FIG. 1 is facilitated is also obtained.
[0017]
Further, in this embodiment, the press-fitting part is limited to the link 19, and the rubber bush 43 and the bearing 46 are press-fitted together with the link 19, so that the number of assembling steps for the rubber bush 43 and the bearing 46 is reduced. At the same time, the accuracy of press-fitting into these links 19 is improved.
[0018]
By the way, in this embodiment, as shown in FIG. 6, the rear cushion 21 is attached to the transmission case 17 via a bracket 53 configured separately from the transmission case 17. In the present embodiment, the bracket 53 is made of sheet metal, and is connected to the rear end upper portion of the transmission case 17 by bolts 54 and 55, and the lower end portion of the rear cushion 21 is rotatably connected thereto. Has been.
Thus, if the bracket 53 is configured separately from the transmission case 17 as described above, the mounting position of the rear cushion 21 can be changed by replacing the bracket 53 when the unit swing type engine 15 is shared by a plurality of models. It becomes possible to optimize according to the dimensions of each model.
In the suspension structure according to the present embodiment, the case where the rubber bush 43 is press-fitted into the link 19 has been described, but it goes without saying that the same effect can be obtained when the bearing 46 is press-fitted.
[0019]
【The invention's effect】
As is apparent from the above description, according to the present invention, in a motorcycle equipped with a unit swing type engine, a vehicle body side bracket is attached to a cross pipe that is horizontally mounted on the left and right main frames of the motorcycle body frame. An engine side bracket separate from the engine is attached to the front of the unit swing type engine, and the front side of the unit swing type engine is moved to the vehicle body side by connecting the engine side bracket to the vehicle body side bracket via a link. In addition to being suspended, a rubber bush is press-fitted into the link at the front end of the link and connected to the vehicle body side bracket, and a bearing or rubber bush is pressed into the link at the rear end of the link and connected to the engine side bracket. The number of parts can be reduced and the assembly man-hours can be reduced. Effect that it is possible to increase the press-fitting accuracy of the bushes or bearings to the component.
[0020]
Further, in a unit swing type engine in which a cylinder protrudes substantially horizontally from a crankcase, an engine side bracket is integrally projected below the front end of the crankcase (for example, Japanese Patent Laid-Open No. Hei 2-162186), When cutting the overlapping surface (joint surface) between the cylinder and the crankcase, the workability is poor because the engine side bracket becomes an obstacle. In contrast, the present invention has a structure in which a separate engine-side bracket is detachably attached to the lower part of the front end of the crankcase, so that when the overlapping surface (combined surface) between the cylinder and the crankcase is cut, the engine There is no side bracket. Therefore, the engine side bracket does not interfere with the cutting process, and the machining efficiency is improved.
[0021]
Furthermore, since the engine side bracket is a separate unit from the unit swing type engine and is detachably attached, the engine side bracket can be used according to the type of motorcycle. Can be attached to any position of the cross pipe that is mounted horizontally between the left and right main frames, so the width dimension of the link whose one end (front end) is connected to the vehicle body side bracket is the distance between the main frames (width It can be set arbitrarily regardless of the dimensions). As a result, the degree of freedom of component layout around the link is increased, and various motorcycles can be supported. Can be shared with two-wheeled vehicles. Therefore, the cost of the unit swing type engine is reduced.
In addition, since the cylinder of the unit swing type engine is inside the left and right main frames, the cylinder is protected by the main frame, and the engine side bracket is connected to the vehicle body side bracket via the left and right single links. Therefore, the vertical swing range of the unit swing type engine due to the vertical vibration of the wheels is suppressed to be small, and the cylinder swings in the range where it overlaps the main frame when viewed from the side. Protected by.
[0022]
Further, the front end connecting portion into which the rubber bush is press-fitted is fitted into the channel-shaped vehicle body side bracket, and a bolt is inserted into the vehicle body side bracket and the rubber bush of the front end connecting portion in the bracket. Is supported at both ends by the vehicle body side bracket, and the front end connecting portion of the link is connected to the vehicle body side bracket, so that even if the vehicle body swings (rolls), the cross pipe bracket supports the bolt firmly. Therefore, the stability of the vehicle body is improved.
[Brief description of the drawings]
FIG. 1 is a cutaway side view of a suspension portion of a front part of a unit swing type engine.
FIG. 2 is a cross-sectional view taken along line AA in FIG.
FIG. 3 is an exploded perspective view of a suspension part of a front part of a unit swing type engine.
FIG. 4 is a side view of a scooter type motorcycle.
FIG. 5 is a partial plan view of a scooter type motorcycle.
FIG. 6 is a side view of a suspension portion at the rear of the unit swing type engine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Scooter type motorcycle 2 ... Head pipe 12 ... Main frame 13 ... Cross pipe 15 ... Unit swing type engine 18 ... Engine side bracket 19 ... Link 20 ... Car body side bracket 43 ... Rubber bush 46 ... Bearing

Claims (1)

In a motorcycle including a unit swing type engine in which a cylinder protrudes substantially horizontally from a crankcase,
A pair of vehicle body side brackets formed in a channel shape is attached to cross pipes that are horizontally mounted on the left and right main frames of the motorcycle body frame,
An engine side bracket separate from the engine is detachably attached below the front end of the crankcase of the unit swing type engine, and the engine side bracket is connected to the vehicle body side bracket via left and right single links. To suspend the front of the unit swing type engine to the vehicle body side,
A rubber bush is press-fitted into the front end connection portion of the link, and the front end connection portion into which the rubber bush is press-fitted is fitted into the channel-shaped vehicle body side bracket, and the vehicle body side bracket and the front end connection portion in the bracket are inserted. A bolt is inserted through the rubber bush, and the bolt is supported at both ends by the vehicle body side bracket, the front end connecting portion of the link is connected to the vehicle body side bracket, and a bearing or rubber bush is connected to the rear end connecting portion of the link. And the rubber bush and the bearing are inside each bracket,
A suspension structure for a unit swing engine in a motorcycle, wherein the cylinder of the unit swing engine is inside the left and right main frames.

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