JPS62146789A - Car body structure of two-wheel barrow - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a vehicle body structure for a two-wheeled vehicle having a pair of left and right frame halves made of pressed sheet metal.

(Background of the Invention) Some small two-wheeled vehicles, such as bicycles and engine-equipped bicycles, have a frame constructed by fixing a pair of left and right frame halves made of pressed sheet metal to each other.

In this case, the frame halves are formed from the head pipe portion at the front end to the end plate portion at the rear end, and the front portions of both frame halves are fixed to each other.

However, sheet metal frames tend to have low rigidity, especially torsional rigidity, which causes a problem in that running stability deteriorates. Further, in this case, a new problem arises in that when the thickness of the sheet metal is increased in order to increase the rigidity, the weight increases.

(Objective of the Invention) The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a motorcycle body structure that can increase rigidity while avoiding an increase in weight, even though the frame is made of sheet metal press. With the goal.

(Structure of the Invention) According to the present invention, this object includes a pair of left and right frame halves made of pressed sheet metal, which are formed to extend diagonally downward and rearward from the head pipe portion at the front end to the end plate portion at the rear end. , in which both the frame halves are fixed to each other at the front part including the head pipe part, a nearly closed box-shaped bracket is fixed near the center of the two frame halves, and a driver seat support is attached to the bracket. This is achieved by a two-wheeled vehicle body structure characterized by fixed metal fittings.

The closed box-shaped bracket itself has high rigidity.
By fixing the bracket and the frame half, they cooperate with each other to increase the rigidity of the entire frame. If the driver seat support fitting is fixed to the bracket so as to pass through the inside of the bracket, the rigidity of the bracket is further increased, and the rigidity of the frame is accordingly increased.

(Example) Fig. 1 is a side view of a motorcycle with a foot pedal according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view of a part thereof, and Figs. 3 and 4 are m- ■ Line sectional view and TV-IV line sectional view, Figures 5 and 6 are side views and plan views of the frame,
Also, Figures 7A to 7D are lines A-A to D-D in Figure 5.
It is each end view along a line.

In FIG. 1, reference numeral 10 indicates a frame, 12 a head pipe section at the front end of the frame, 14 a front fork held by the head pipe section 12 so as to be rotatable left and right, 16 a steering front wheel,
18 is a steering wheel handle, 20 is an end plate portion at the rear end of the frame 10, and 22 is a driving rear wheel attached to this end plate portion.

As shown in Fig. 5.6, the frame 10 is a pair of left and right frame halves 10a made of sheet metal press.

10a by fixing them together.

That is, each frame half 10a has a head pipe section 12.
It is press-molded into a generally arched shape convex upward so as to extend obliquely downward and rearward from the end plate portion 20 to the end plate portion 20 . The front end of the frame half 10a is fixed to the steering shaft cylinder 24 so as to wrap around the steering shaft cylinder 24 from left and right sides (Fig. 7A).
. A reinforcing plate 26 is fixed to the inner surface of the end plate portion 20 of the frame half 10a. Frame half 10a
The upper edges of the helmet vibrator 12 are fixed to each other at the rear (FIG. 7B), and a fuel tank 28 is housed in a space surrounded by each frame half 10a.

Note that an appropriate reinforcing plate 30 is provided inside each frame half 10a.
(30a, 30b, 30c, 30d; see Section 5.7, Figure) are fixed by spot welding or the like. 6th.
In Fig. 70, numeral 31 represents a pair of left and right rear brake mounting brackets.

32 is a nearly closed box-shaped bracket.

As shown in Fig. 2.4, this bracket 32 includes an outer panel 32a that is press-molded to be convex upward, and an inner peripheral surface of the outer panel 32a so as to close the lower opening of the outer panel 32a. A closed space is formed by the outer plate 32a and the inner plate 32b. The left and right lower edges of the outer panel 32a extend downward along the reinforcing plate 30c of the frame 10, and are attached to the reinforcing plate 30c. Since the bracket 32 is made in the shape of a closed box, its rigidity is extremely high.
Since the 0a are connected to each other, the rigidity of the frame 10 itself increases.

34 is a vibrator as a driver's seat support fitting, and this pipe 34 passes through the inside of the bracket 32, and its lower end is connected to the lower plate 3.
It is fixed so as to protrude downward from 2b. Therefore, the rigidity of the bracket 32 is further increased. 36 is a driver's seat, a seat pipe 38 is fixed to the lower surface of this driver's seat 36, and this seat pipe 38 is connected to the pipe 34.
is inserted into. An axial notch or slot is provided at the upper end of the vibrator 34, and the seat pipe 38 and seat 36 can be fixed at a predetermined height by a seat pin 40 perpendicular to the slot.

42 is a vertically long dynamic crab knit, and a single-cylinder forced air-cooled two-stroke engine 44 at the top thereof has a cylinder 44a that projects rearward. The moving crab knit 42 has its upper part fixed to the frame 10 by a bracket 46, and its lower part coupled to the end plate part 20 by a chainstay 48. That is, between the two frame halves 10a, the bracket 46 having a substantially inverted U-shaped cross section is fixed by ports 52 and 54 so as to protrude below the seat 36 (see FIG. 3). The upper part of the moving crab knit 42 inserted from below is fixed by a port 56. As shown in FIG. 2, a fan 60 driven by a crankshaft 58, a generator 62, a centrifugal automatic clutch 64, and a planetary gear reducer 66 are disposed in this moving crab knit 42 in this order from above.

A foot pedal 68 is rotatably held at the bottom of the movable crab knit 42, and the rotation of the pedal 68 is transmitted to the crank gear 70 via a one-way clutch (not shown).

When the rotational speed of the engine 44 exceeds a certain level, the clutch 64 is connected and the output of the engine 44 is transmitted to the crank gear 70 via the reduction gear 66, bevel gear 72, and one-way clutch (not shown). A plurality of rear gears 74 having different numbers of teeth are fixed to the rear wheel 22.

Further, an external transmission derailleur 76 is attached to the end plate portion 20. A chain 78 is wound around the crank gear 70, the rear gear 74, and the rear delay luff 6.

The cylinder 44a of the engine 44 is connected to the engine cover 8.
The fan 60 takes in cooling air from the front of the engine 44 and sends it into the cover 80 as shown by the arrow in FIG. And this cooling air is sent to the cylinder 44.
After being cooled, it is discharged from the discharge port 82 at the top of the cover 80 between the frame halves 10a.

In FIG. 1.2, 84 is a lubricating oil tank disposed above the cylinder 44a, 86 is an air cleaner disposed in front of it, and 88 is a carburetor. Further, 90 is an exhaust muffler, which is fixed to the pipe 34 that supports the seat 36,
The exhaust pipe 92 passes between both frame halves 10a and is connected to an exhaust port on the lower surface of the cylinder 44a. Note that 94 is a rear fender that covers this muffler 90 from above.

According to this embodiment, the engine 44 and the pedals 68 work together to transmit driving force to the rear wheels 22, and if either one is stopped, the driving force of only the other is transmitted to the rear wheels 22. While driving, the crank gear 70 continues to rotate due to the chain 78, and if a manual gear shift lever (not shown) is operated during this time, the delay luff 6 moves the chain 78 to a different rear gear 7.
In step 4, the gear shift is performed by changing the gear ratio.

Although the above embodiments apply the present invention to a two-wheeled motor vehicle with a foot pedal, the present invention is not limited thereto, and can also be applied to a two-wheeled motor vehicle without pedals or a bicycle.
The present invention also includes these.

Further, at least one of the head pipe section 12 and the end plate section 20 may be made separate and fixed to the frame half body 10a.

Further, the nearly closed box-shaped bracket may be provided with an appropriate opening for weight reduction.

(Effects of the Invention) As described above, the present invention fixes a pair of left and right frame halves made of sheet metal presses to each other at the front, and fixes an almost closed box-shaped bracket near the center of these frames. Since the driver's seat support bracket is fixed to the frame, the high rigidity of the bracket itself can be utilized to increase the rigidity of the frame while avoiding an increase in the weight of the entire frame.

[Brief explanation of drawings]

Fig. 1 is a side view of a motorcycle with a foot pedal according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view of a part thereof, and Figs. 3 and 4 are sectional views taken along the line ■-m in Fig. 2. and rV-IV line sectional view, Figures 5 and 6 are a side view and a plan view of the frame,
Also, Figures 7A to 7D are lines A-A to D-D in Figure 5.
FIG. 6 is a line end view. DESCRIPTION OF SYMBOLS 10... Frame, 10a... Frame half body, 12... Head pipe part, 20... End plate part, 32... Bracket, 34... Pipe as driver seat support fitting, 36...
...Driving seat.

Claims (1)

[Scope of Claims] A pair of left and right frame halves made of pressed sheet metal are formed to extend diagonally downward and rearward from a head pipe portion at the front end to an end plate portion at the rear end, and both frame halves are connected to the The vehicle is fixed to each other at the front portion including the head pipe portion, and is characterized by comprising a substantially closed box-shaped bracket fixed near the center of both frame halves, and a driver seat support fitting being fixed to this bracket. The body structure of a two-wheeled vehicle.