JPH01275284A - Sub-body structure of motorcycle - Google Patents

Abstract

PURPOSE:To enhance the strength of an extended part and a bracket by extending a side part of an engine guard so as to cover the undersurface of an air exhaust pipe situated sideways below the engine, locating the protruding end of foot bracket above the exhaust pipe, and coupling the extended part with the protruding end. CONSTITUTION:One side of an engine guard 64 enclosing the undersurface of engine 25 is extending so as to enclose the undersurface of an air exhaust pipe 29. That is, this undersurface of exhaust pipe 29 is enclosed through utilization of the engine guide 64, so that the exhaust pipe 29 is protected. The extended part of engine guard 64 and the protruding end of a foot rest bracket 54 are coupled together and pinch the exhaust pipe 29 from above and below, so that they are made in a frame-shaped structure, which allows the two to reinforce each other to lead to enhancement of the strength.

Description

[Detailed description of the invention] (Field of application in industry) This invention provides an engine guard that covers the lower surface of the engine;
The present invention relates to a lower body structure for a motorcycle, including a footrest bracket that supports a footrest.

(Prior Art) In many motorcycles, the exhaust pipe of the engine extends rearward through the lower side of the engine.

Furthermore, since the engine of a motorcycle is usually installed in the F section of the vehicle body, there is a risk that the engine may come into contact with obstacles on the road surface while the motorcycle is running. At this time, in order to prevent the engine from being easily damaged, some engines are equipped with an engine guard that covers the underside of the engine.

In the above case, there is a risk that the exhaust pipe located at the lower side of the engine may also come into contact with obstacles on the road surface.

Therefore, in order to protect the exhaust pipe with a simple structure, it is conceivable to extend an example part of the engine guard to cover the lower surface of the exhaust pipe.

(Problem to be Solved by the Invention) By the way, when trying to protect the exhaust pipe as described above, if one side of the engine guard is simply extended, it becomes cantilevered and does not have sufficient strength. There is a possibility that it cannot be secured.

On the other hand, motorcycles are equipped with footrests,
This is normally supported by a protruding end of a footrest bracket that protrudes outward from a part of the vehicle body frame located on the lower side of the engine. Also in this case, since the footrest bracket is cantilevered, it is desired that the structure be as simple as possible to increase its strength.

(Object of the Invention) This invention has been made by paying attention to the circumstances described in (-). ,
The purpose is to improve each strength of a footrest bracket with a structure as simple as possible.

(Structure of the Invention) The present invention is characterized in that an example part of the engine guard extends so as to cover the lower surface of the exhaust pipe located on the lower side of the engine, on the other hand,
The engine guard is located above the exhaust pipe on the projecting end side of the footrest bracket, and the extending portion of the engine guard is connected to the projecting end of the footrest bracket.

(for production) The effect of the above configuration is as follows.

An example part of the engine guard 64 that covers the lower surface of the engine 25 extends to cover the lower surface of the exhaust pipe 29. That is, by using the engine guard 64, the lower surface of the exhaust pipe 29 is covered. Therefore, the exhaust pipe 29 can be protected with a simple configuration.

In the above case, since one example of the engine guard 64 is extended, the strength of the extended portion becomes a problem. However, the extending portion of the engine guard 64 and the protruding end of the footrest bracket 54 are closely connected, and both the extending portion of the engine guard 64 and the footless pluget 54 are connected to the exhaust pipe 29. Since they are sandwiched from above and below, they have a frame-like structure, and as a result, they are mutually reinforced and their strength is improved.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

In FIGS. 2 and 3, 1 is a motorcycle, and 2 is its body frame. This body frame 2 has a semi-double cradle shape. That is, this body frame 2 has a head vibe 3 at its front part, a king frame 4 extends rearward and downward from the second part of this head pipe 3, and furthermore,
A pair of left and right seat pillar tubes 6 extend in the direction F from the rear end of the main frame 4. On the other hand, a pair of seat pillar tubes 6 extend rearward and downward from the lower part of the head pipe 3, and the rear end thereof is "1". A sub-frame 7 connected to the lower end is provided. This sub-frame 7 includes a down tube 8 extending downward from the lower part of the head pipe 3, and a pair of left and right lower frames 9 and 9 that extend downward from the lower end of the down tube 8 and then are bent rearward. The front end of the lower frame 9 is screwed to the lower end of the town tube 8 with bolts 10.

A front fork 11 is supported on the above-mentioned Radvibe 3 so as to be freely steerable. That is, this front lens 11 has a steering shaft inserted into the head pipe 3, and this steering shaft is rotatable about the axis of the head pipe 3. An upper bracket 12 is attached to the upper end of the head pipe 3, and a lower bracket 13 is attached to the lower end. A pair of left and right fork vibrators 14 are attached to the upper bracket 12 and the lower bracket 13.
．． 14 is supported, a front wheel 15 is supported between the lower ends of both fork pipes 14 and 14, and a handle 16 is supported on the upper bracket 12 on the other hand.

A pivot shaft 18 is provided at the bottom of the seat pillar tube 6.6.
The rear arm 19 is pivotally supported to be vertically swingable, and the rear wheel 20 is supported at the swinging end of the rear arm 19.

Further, a shock absorber 21 is interposed between the upper part of the seat pillar tube 6.6 and the rear arm 19 via a link mechanism 22. 23 is the road surface. Note that the shock absorber 21 and link mechanism 22 will be described later.

25 is a 1 cylinder 4 cycle engine, this engine 2
5 is located inside the small frame 2 and fastened to the small frame 2. A carburetor 26 is attached to the intake hole of the engine 25, and an air cleaner 27 is provided to clean the outside air taken into the carburetor 26.

An exhaust pipe 29 is connected to the exhaust hole of the engine 25. In this case, the engine 25 has two exhaust holes, and therefore the exhaust pipe 29 includes a pair of left and right front pipes 30, 30 connected to each exhaust hole. Also,
The rear ends of the front tubes 30 and 30 are connected to each other by a collecting tube 31. The river is provided with a rear pipe 32 extending rearward from the collecting pipe 31, and the rear end of the rear pipe 32 is bent into a rear bevel shape, and a muffler 33 is attached to the end. In the above case, the rear pipe 32 extends on the left side of the lower part of the engine 25 and along the left side of the left F section frame 9 of both lower frames 9.9.

-4 A fuel tank 35 for supplying fuel to the second carburetor 26 is provided. This fuel tank 35 is comprised of a pair of front tanks 36. which are provided so as to sandwich the main frame 4 from the left and right sides.
36, both front tanks 36.36 are Porto 36
a) to each other) and the above main frame 4
supported above.

Further, the fuel tank 35 has a rear tank 38 at the rear of the vehicle body frame 2, and this rear tank 38 is attached to a stay 6a projecting from the seat pillar tube 6 by a thread 1j. This rear tank 38 has an inverted U-shape when viewed from the front.

The engine 25 is provided with a driving chain wheel 41, and the rear wheel 20 is provided with a driven chain wheel 42.
A transmission tube 43 is wrapped around ffi41.42. The engine 25 operates by sucking in outside air through an air cleaner 27 and a carburetor 26, and by sucking fuel from a fuel tank 35 through the carburetor 26. The power of this engine 25 is transferred to the transmission chain 4
If the signal is transmitted to the rear wheel 20 via the third or the like, the motorcycle 1 can run.

The rear tank 38 supports a seat 44 on its -F side. In other words, this rear tank 38 also serves as a support bracket for the seat 44.

Additionally, 45 is a water tank.

In FIG. 3, the gap size between the -F ends of the front tubes 30, 30 is smaller than the diameter of the down tube 8. For this reason, if both front pipes 30.30 are fixed to the collecting pipe 31, the down duplex 8 will become an obstacle, making it impossible to attach and detach the front pipes 30, 30 to the engine 25.

Therefore, as shown in FIG. 1, the two ends of each front pipe 30 are removably fitted into flanges 25a provided at each exhaust port 1 of the engine 25, and the spring 30
A is biased to maintain this fit.

On the other hand, the lower end of each front pipe 30 is removably fitted into a pair of left and right fitting cylinders 31a, 31a formed at the surface end of the collecting pipe 31, and this fitting is maintained by a spring 30b. is energized by

When removing the front pipe 30 from the engine 25 side or the collecting pipe 31 side, first remove each spring 30a.

30b, then release the above fitting and remove the front tube 3.
Just remove 0.

The connecting portion between the seat pillar tube 6.6 and the lower frames 9, 9 will be explained in more detail with reference to FIGS. 1, 4, and 5.

The lower end of the left seat pillar tube 6 of the above seat pillar tubes 6.6 is the right seat pillar tube 6.
It is shorter than the bottom of the . The lower end of the left seat pillar tube 6 and a portion slightly above the lower end of the right side are connected by an upper cross pipe 46 that is a cross member.

Further, an arm 47 is provided to protrude downward from the left end of the upper cross pipe 46 from a portion near the center in the vehicle width direction, and the lower end of this arm 47 and the lower end of the right seat pillar tube 6 are connected to the lower end of the upper cross pipe 46. They are connected by a cross pipe 48.

The rear end of the right lower frame 9 of the lower frames 9.9 is welded to the right end of the lower cross vibe 48 in -1-. Further, the rear end of the left lower frame 9 is screwed into the left side surface of the lower end of the arm 47 with one bolt 49.

In the case of F, the rear end of the left lower frame 9 and the arm 4
7, the rear end of the five-part frame 9 is formed with four surfaces 9a, while the arm 47 is formed with a convex surface 47a. These four surfaces 9a and the convex surface 47a fit into each other, thereby firmly connecting the five-part frame 9 and the arm 47.

In addition, a pair of left and right support plays 1-50 are provided at the left and right center portions of the partial cross pipe 46 and the lower cross vibe 48.
50 are welded. And this support plate 50
．． 50, the strength 1u of the leech section cross pipe 46 and the do section cross pipe 48 is improved.

1- A right footrest bracket 51 is screwed onto the right end of the lower cross vibe 48 by bolts 52, and a right footrest 53 is attached to the right footrest bracket 51.

On the other hand, a left footrest bracket 54 is fastened together with the rear end of the lower frame 9 by the bolt 49 to the lower end of the arm 47.
The left footrest bracket 54 is secured by another bolt 49'. This left footrest bracket 54 protrudes toward the left, and its protruding end is located on the -L side of the rear tube 32;
It is located to the left of the bipedal rear tube 32, and a left footrest 55 is attached to its protruding end. Further, a nut 56 is welded to the projecting end of the left footrest bracket 54 and slightly in front of the left footrest 55.

In the above case, since the arm 47 is provided closer to the center in the vehicle width direction than the left seat pillar tube 6,
The arm 47 is located below the seat pillar duplex 6 on the left side.
A recess 57 will be formed on the left side. and,
The rear pipe 32 is fitted so as to pass through this recess 57, that is, the vehicle body is constructed so that the lower dimension and narrow width dimension of the vehicle body are made as small as possible.

1 to 5, a rectangular highly rigid frame body 60 is provided on the front surface of the sub-frame 7. As shown in FIGS. The two parts of this frame body 60 are secured to the down tube 8 by a pair of right and left bolts 6 and 61, and the lower part of the frame body 60 is secured to the left and right lower frame 9 by a pair of right and left bolts 62, 62.
Being forced out.

64 is an engine guard. This engine guard 64
is a flat U-shaped plate material when viewed from the front, and is composed of a bottom plate 65 and left and right side plates 66 and 66. The engine guard 64 covers the left and right lower frames 9.9 and the engine 25 from below, and the left side of the engine guard 64 extends leftward to cover the lower surfaces of the collecting pipe 31 and the rear pipe 32. is covered. Therefore, the engine guard 64 protects the engine 25 as well as the collecting pipe 31 and the rear pipe 32.

A pair of left and right brackets h64a, 64a are welded to the front end of the engine guard 64, and each bracket 64a
are firmly fastened together with the frame 60 to the left and right rear tubes 9.9 by the aforementioned bolts 62, 62. on the other hand,
A protruding piece 6 is attached to the right side plate 66 at the rear of the engine guard 64.
7 is integrally molded and is screwed into the right footrest bracket 51 with a bolt 68.

Further, a projecting piece 69 is integrally formed on the left side plate 66 at the rear of the engine guard 64, and is fastened with a bolt 70 that is inserted into a nut 56 provided on the left footrest bracket 1-54. That is, according to this configuration, the left end of the engine guard 64 that extends to cover the lower surfaces of the collecting pipe 31 and the rear pipe 32 and the protruding end of the left footrest bracket 54 are connected to each other by the bolt 70. Therefore, the left footrest 55 uppers 1 to 54 and the engine guard 64 mutually reinforce each other, thereby improving the strength.

In addition, in the case described above, since both the left end of the engine guard 64 and the left footrest bracket 54 sandwich the rear pipe 32 from above and below, they cooperate with each other to form a frame-like structure, and as a result, The strengths and sorrows of these two ministries will continue to improve.
- to do.

In addition, a large number of through holes 71 are formed in the bottom opening 65, and these through holes 71 are provided for making the engine guard 64 meterable.

In FIG. 1 and FIGS. 4 to 7, the engine 25 is fastened to the small body frame 2 in the following manner. That is, the front portion of the crankcase 73 of the engine 25 is screwed onto a bracket 74 screwed onto the down duplex 8 by means of bolts 75. On the other hand, the rear part of the power transmission case 77 connected to the crankcase 73 is supported by the seat pillar tube 6.6 by the pivot shaft 18, and the rear lower end of the power transmission case 77 is in front of the support plate 50.50. The support plate 50, 50 is fitted into the front part of the support plate 50, 50, and is screwed to the front part of the support plate 50, 50 by bolts 78.

- A portion of the left side surface of the crankcase 73 protrudes laterally, and a flywheel magneto is housed inside this protrusion 73a.

The protruding portion 73a is the engine guard 6 when viewed from above.
It is located on the inside of 4.

A part of the right side surface of the power transmission case 77 protrudes laterally, and a clutch that connects and disconnects power from the engine 25 to the drive chain wheel 41 is housed inside this protrusion 77a. . The -F protrusion 11a is also located inside the engine guard 64 in plan view.

Historically, a change pedal 8o for changing gears is pivotally supported on the left side of the power transmission case 77 so as to be movable downward from -L, and the front end of this change pedal 80 serves as a foot pedal 80a. Then, when the foot on the left footrest 55 is operated by stepping on the foot pedal portion 80a, a gear shift operation is performed.

The change pedal 80 is located inward in the vehicle width direction from the left end of the engine guard 64 in plan view, except for a small portion of the foot part 80a.

Further, a brake pedal 82 is pivotally supported on the right seat pillar duplex 6 by a pivot shaft 83 so as to be movable up and down, and the front end of this brake pedal 82 serves as a foot pedal part 82a. When the foot on the right footrest 53 is operated to press the foot pedal 82a, braking is performed by the brake provided on the rear wheel 20. This brake pedal 82 is also located inward in the vehicle width direction from the right end of the engine guard 64 in plan view, except for a small portion of the foot pedal 82a.

That is, by locating each of the above-mentioned protrusions 73a, 73a, change pedal 80, and brake pedal 82 inward from the left and right ends of the engine guard 64,
This engine guard 64 sufficiently protects each device.

The lower part of the water tank 45 is fixed to the front part of the side plate 66 by bolts 45a.

At this time, this bolt 45a is screwed into a nut 45b welded to the inner surface of the side plate 66.

6 and 7, the buffer 21 and the link mechanism 2
2 will be explained in more detail.

The shock absorber 21 is a retractable hydraulic cylinder damper 84.
and a spring 85 that biases the damper 84 in the direction of extension, and the upper end of the damper 84 is pivotally supported by a first support shaft 87 to a cross vibe 86 installed at the upper end of the seat pillar tube 6.6. There is.

On the other hand, the link mechanism 22 has a main link 89 that is pivotably supported vertically by a second support shaft 88 at the rear of the support plate 50.50, and the damper 84 is attached to the rotation end of the main link 89. The lower end is pivotally supported by a third support shaft 90.

Further, a pair of left and right connecting links 91 are pivotally supported by a fourth support shaft 92 at the front and rear midpoints of the main link 89, and the rotating ends of these connecting links 91.91 are attached to a cross pipe 93 attached to the rear arm 19. is pivotally supported by a fifth support shaft 94.

Thus, the shock absorber 21 buffers the impact that is transmitted from the road surface 23 to the vehicle body frame 2 through the rear wheels 20 and the rear arm 19.

Further, at this time, the link mechanism 22 functions as follows.

In other words, when the rear wheel 20 receives an impact from the road surface 23 and the rear arm 19 rotates upward while the motorcycle l is running, this link mechanism 22 reduces the damper 84 as the rear arm 19 rotates upward. This increases non-linearly, thereby improving the tracking ability of the rear wheels 20 with respect to the road surface 23.

In the case of two legs, the support plate 50.50 supports the engine 25 at the front and the link mechanism 22 at the rear, thus making effective use of the support plate 50.50.

In FIGS. 2, 8, and 9, 96 is a side stand, and this side stand 96 is pivoted to the seat pillar tube 6 by a pivot shaft 97 so as to be vertically movable. 2 and 8 while the motorcycle 1 is running.
As shown by the solid line in the figure, it is maintained in a position rotated to one side by -1. In this position, the rotating end side of the side stand 96 is located below the rear tube 32 in plan view, as shown in FIG. In other words, the side stand 96 when not in use is prevented from protruding to the outside of the vehicle body.
This prevents it from getting in the way of the rider.

On the other hand, when parking the motorcycle 1, as shown by the imaginary line in the same figure above and in FIG. It can be made to stand on its own on the road surface 23.

(Effects of the Invention) According to the present invention, an example part of the engine guard extends so as to cover the lower surface of the exhaust pipe located on the lower side of the engine, and the protruding end side of the footrest bracket is extended to the same side as the exhaust pipe. Since the engine guard is located above the engine guard and the extending portion of the engine guard is connected to the projecting end of the footrest bracket, the exhaust pipe can be protected with a simple structure by using the engine guard.

- In the case of item F, the extending part on one side of the engine guard and the protruding end of the footrest bracket are connected inversely, and both the extending part of the engine guard and the two-1-rest bracket Since the tube is sandwiched from the -L-do, the two form a frame-like structure, and their strength is effectively improved.

Moreover, in this case, the strength can be improved without providing a separate reinforcing member, so this improvement in strength can be achieved with a simple configuration.

[Brief explanation of the drawing]

The drawings show an embodiment of the invention, in which Fig. 1 is a partially enlarged side view of Fig. 2, Fig. 2 is an overall side view of the motorcycle, Fig. 3 is a front view, and Fig. 4 is a plan view of Fig. 1. Figure 5 is the V of Figure 1.
-vl arrow sectional view, Figure 6 is a partially enlarged sectional view of Figure 2,
Figure 7 is a sectional view taken along the Vll-Vlll arrow in Figure 6;
The figure is a plan view of the side stand when not in use, and FIG. 9 is a rear view of the side stand when in use. 1. Motorcycle, 2. Body frame, 25-engine, 29. Exhaust pipe, 54. Left footrest bracket (footrest bracket), 55. Left footrest (footrest 1-), 64. Engine guard.

Claims (1)

[Claims] 1. Attach the engine to the vehicle body frame so that the exhaust pipe extending rearward from the engine passes through the lower side of the engine, and on the other hand, attach the footrest bracket that supports the footrest to the vehicle body frame located at the lower side of the engine. In the lower body structure of a motorcycle, in which an engine guard is attached to the body frame, the engine guard protrudes outward from a part of the engine and covers the lower surface of the engine. A motorcycle body in which one side of the engine guard extends, the protruding end of the footrest bracket is located above the exhaust pipe, and the extending part of the engine guard is connected to the protruding end of the footrest bracket. Undercarriage.