JP3187533B2 - Body structure of motorcycle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cradle type vehicle body structure for a motorcycle.

[0002]

2. Description of the Related Art The cradle-type body frame of a motorcycle generally has a front pipe which constitutes a front end thereof and supports a front fork so as to be steerable, and extends rearward and downward from an upper portion of the head pipe. The main frame includes a down tube extending rearward and downward from a lower portion of the head pipe, and a gusset plate provided at each front of the main frame and the down tube.

Some motorcycles include a fuel tank disposed behind the head pipe and a pair of radiators disposed near the left and right sides of the gusset plate and extending vertically. In this case, usually the longitudinal
Each end of the pipe to each of these radiators
A communication pipe is provided to connect the insides of the two radiators to each other, and the communication pipes make the internal pressures of the radiators equal to each other by allowing the cooling water to flow freely.

[0004]

By the way, in the above conventional structure, the gusset plate connects the head pipe, the main frame and the down tube to each other, and
These joints form a large partition wall that partitions the left and right sides thereof without any gap. Therefore, the communication pipe for communicating a radiator located near the left and right sides of the body frame is provided at an outer edge of the joint. Department is to be bypassed.

However, in this case, the communication pipe becomes long, and the communication pipe may be greatly bent by the detour, so that the flow of cooling water may be obstructed.

Therefore, conventionally, the above-mentioned communicating pipe has to be
It has been proposed to have a shape that extends linearly in the direction
(For example, Japanese Utility Model Laid-Open No. 58-43515).
If the cooling water flows smoothly through the communication pipe,
Can be

However, the distance between the left and right radiators is different from each other.
Error is likely to occur, so each end in the longitudinal direction is
The communication pipe connected to the eta is straight as described above.
When der Ru, to absorb the error in the communication pipe
Is not easy, so that the communication path is connected to each radiator.
Piping work to connect each end of Ip becomes difficult
There is a risk.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a communication pipe connecting radiators on the left and right sides of a vehicle body frame to allow cooling water to flow smoothly . Even in this case, each radiator
The purpose of the present invention is to facilitate the work of connecting a communication pipe to a pipe .

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention is characterized in that a body pipe 2 constitutes a front end of the head pipe 18 for supporting a front fork 4 in a steerable manner. A main frame 19 extending rearward and downward from an upper portion of the head pipe 18, a down tube 23 extending rearward and downward from a lower portion of the head pipe 18, and front portions of the main frame 19 and the down tube 23. A gusset plate 29 to be erected, a fuel tank 15 disposed behind the head pipe 18, and a radiator 34 extending vertically in the vicinity of each of the left and right sides of the gusset plate 29. Each longitudinal end is connected to each of these radiators 34
In the vehicle body structure of the motorcycle provided with a flexible communication pipe 35 for communicating the insides of the radiators 34 and 34 with each other,

1) The head pipe 18 is viewed from the side of the vehicle body.
And the rear edge of the gusset plate 29, a penetrating space 32 penetrating in the vehicle width direction is formed, and the communication pipe 35 is disposed so as to penetrate the space 32,

2) The radiator 34 is viewed from the side of the vehicle body .
At least a portion of the communication pipe 35 is disposed in front of the radiator 34, and the communication pipe 35 is connected to the radiator 34.
Arranged above

3) Connect the communication pipe 35 in its longitudinal direction.
Bent so that the middle part becomes a convex arc shape forward,

4) Each end of the communication pipe 35 in the longitudinal direction
As you face the rear of the vehicle,
Incline,

5) In the vehicle body plan view, the communication pipe 35
The point is that each end is disposed so as to overlap the radiator 34 .

[0015]

[Operation] The operation of the above configuration is as follows.

The fuel tank 15 is located behind the head pipe 18.
Arranged to the longitudinal ends of the direction right and left radiators 34,
In the case where a flexible communication pipe 35 connected to the radiator 34 and communicating the radiators 34 is provided,

1) The head pipe 18 and
A through space 32 is formed between the gusset plate 29 and the rear edge of the gusset plate 29 so as to penetrate in the vehicle body width direction. The communication pipe 35 is provided to penetrate the space 32.

For this reason, as in the prior art, the head pipe 1
8, the front part of the main frame 19, the front part of the down tube 23, and the combined body 18, 1 by the gusset plate 29
The outer edge of 9,23,29 so as to bypass Rendoripa
Since the pipe 35 need not be provided, the communication pipe 35 can be shortened, and the communication pipe 35 can be made more linear.

[0019] 2) when the body is viewed from the side, the radiator 34
At least a portion of the communication pipe 35 is disposed in front of the radiator 34, and the communication pipe 35 is connected to the radiator 34.
It is disposed above the.

A front fork 4 is supported on the head pipe 18 so as to be steerable. Usually, spaces for allowing the steering operation of the front fork 4 are provided on the left and right sides of the head pipe 18. The space is secured by the fuel tank 15 and each radiator 34.
It is to be positioned in front of the.

The sky above the radiator 34
The space is connected to the space in front of the radiator 34.
Therefore, a large space can be obtained by these two spaces.

Therefore, as described above, the radiator 34
At least a portion of the communication pipe 35 is disposed on the front side of the radiator 34, and the communication pipe 35 is
The upper radiator
When each end of the communication pipe 35 is connected to the
The plumbing work (hereinafter referred to as "plumbing work")
Generally, the fuel tank 15 and each radiator 3 having a large shape
4 can be made from the front side and the upper side of each of the radiators 34 by using the wide space.

3) Connecting the communication pipe 35 in its longitudinal direction
It is bent so that the middle part becomes a convex arc shape forward.
You.

For this reason, the "piping work"
), The left and right radiators 34, 34
When connecting the ends of the Ip 35,
Even if there is an error in the arrangement distance of the
If the bending angle of the communication pipe 35 is changed,
The difference can be easily absorbed.

As described above, the communication pipe 35 is
The middle part in the longitudinal direction will be a convex arc shape forward
The communication pipe 35 is bent.
A part of the space 32 penetrating the middle part,
Connection of each end of the communicating pipes 35 in the motor 34 side
Minutes are offset from each other in the front-back direction.

Therefore, the left side of the gusset plate 29
The communication pipe is connected to each radiator 34 disposed on each side of the right.
In order to connect the ends of the loop 35, first, the space
32 to penetrate the communication pipe 35 in the vehicle width direction.
When performing the operation, the above-mentioned connection on each radiator 34 side is performed.
The ties do not interfere with the above penetration work.
Is stopped.

4) Each end of the communication pipe 35 in the longitudinal direction
As you face the rear of the vehicle,
It is inclined.

For this reason, in the plan view of the vehicle body, the communication pipe
35 is a substantially U-shaped arc, which is supposed to be
Compared to the case where the communication pipe 35 is formed in a U-shape,
Of the communication pipe 35 can be further shortened.

5) In the vehicle body plan view, the communication pipe 35
Each end is arranged so as to overlap the radiator 34.
You.

For this reason, the communication pipe 35 is
As shown in the figure, the middle part of the
However, as described above, each end of the communication pipe 35
Is overlapped on the radiator 34, and the radiator 34
And the communication pipe 35 are provided compactly in the front-rear direction.
You.

[0031]

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

In FIGS. 1 to 3, reference numeral 1 denotes a motorcycle which is a saddle-ride type vehicle, and an arrow Fr in the drawings indicates the front thereof. The left and right described below refer to the direction toward the front.

A body frame 2 of the motorcycle 1 has a front fork 4 supported at its front end so as to be steerable. A front wheel 7 is supported on the lower end of the front fork 4 by an axle 6, and a handle 8 is mounted on the upper end of the front fork 4.

On the other hand, a rear arm 10 is pivotally supported on the lower rear portion of the body frame 2 so as to be vertically swingable, and a rear wheel 11 is supported on a swinging end of the rear arm 10. 12 is a shock absorber, and 12a is a link mechanism. An engine 13 is mounted on the vehicle body frame 2, and a power transmission device 13 a is connected to the engine 13. The power of the engine 13 is transmitted to the power transmission device 13a.
Through the chain winding mechanism 14 to the rear wheel 11. In addition, 15 is a fuel tank, 16
Is a seat, and 17 is a footrest.

The body frame 2 has a head pipe 18 constituting a front end thereof. The head pipe 18 supports the front fork 4 as described above, and the fuel tank 15 is disposed behind the head pipe 18. Has been established. From the upper part of the head pipe 18 to the rear lower part,
A main frame 19 made of a circular pipe extends, and a pair of left and right circular pipe rear arm brackets 20 extend further rearward and downward from the extension end of the main frame 19. A pivot shaft 21 is provided below the rear arm bracket 20.
Thus, the rear arm 10 is pivotally supported as described above.

On the other hand, a down tube 23 extends downward from the lower portion of the head pipe 18 toward the rear. The down tube 23 is composed of one front tube 24 constituting the front part thereof and a pair of left and right rear tubes 25 constituting the rear part of the down tube 23. The front tube 24 is made of a square pipe. Yes, each rear tube 2
5 is a circular pipe.

The rear tubes 25 are located at the bottom of the vehicle body, and the rear ends of these rear tubes 25 are connected to the lower ends of the corresponding rear arm brackets 20. 26 is a cross pipe.

A circular pipe stay 27 is provided between the rear end of the main frame 19 and the front and rear halfway of the front tube 24.
Has been erected. A front portion of the main frame 19;
The front tube 2 which is the front of the down tube 23
A gusset plate 29 made of sheet metal and provided on the stay 4 and the stay 27 is provided. This gusset plate 2
Reference numeral 9 denotes a configuration in which left and right plates 30 and 31 facing each other are joined in the middle, and the three members of the main frame 19, the front tube 24, and the stay 27 are firmly joined by welding. The rigidity of the front part of the body frame 2 is increased.

In particular, a through space 32 is formed between the head pipe 18 and the rear edge of the gusset plate 29 when viewed from the side of the vehicle body shown in FIG. More specifically, the head pipe 18 and the gusset plate 29 are provided to be separated from each other in the front and rear directions.
A space 32 is formed between the space 32 and the front edge portion.

In particular, as shown in FIG. 1, the length a from the front edge of the gusset plate 29 to the head pipe 18 along the main frame 19 and the gusset plate 29
From the leading edge of the head pipe 18 along the front tube 24
Has a relationship of a <b with the length b.

In FIG. 1 and FIG.
Radiators 34, 34 extending in the vertical direction are disposed near the left and right sides of the gusset plate 29 constituting the front part, respectively. Each of these radiators 34 is for cooling the cooling water of the engine 13 by air.

[0042] each longitudinal end each radiator 3
4 , 34 via a pipe joint 36
Communication for communicating the respective inner ends of Luo both radiators 34 and 34
Through pipes 35 are provided. The communication pipe 35 is made of a tube with a flexible property, the radiator 34
Are connected to each other. And this communication pipe 3
5 allows the internal pressures of the radiators 34 and 34 to be equal to each other by allowing the cooling water to flow freely.

In the above configuration, when the vehicle is viewed from the side,
The communication pipe 35 is less in front of the radiator 34.
A front part, which is a part of both, is provided. In addition,
The passage pipe 35 is disposed above the radiator 34.
Have been.

The communication pipe 35 is arranged so that a middle part in the longitudinal direction is bent slightly forward to form a convex arc, and penetrates the space 32.

That is, in the related art, the communication pipe 35 is provided so as to bypass the outer edges of the combined bodies 18, 19, 24, 29 of the head pipe 18, the main frame 19, the front tube 24, and the gusset plate 29. However, on the other hand, the communication pipe 35 is shortened and provided more linearly.

In FIGS. 1 and 3, the space 32 is disposed near the front of each of the radiators 34, 34.
Each end of the communication pipe 35 in the longitudinal direction is a vehicle body.
It is inclined so that it goes to the outside of the car body as it goes backward
I have.

[0047] On the other hand, of the upper end of the respective radiators 34, upper Kipa type joint 36 is protruded upward from an end portion of the gusset plate 29 side, and, at the vehicle body plan view (FIG. 3), above Each pipe joint 36 projects forward from the radiator 34 and obliquely forward toward the gusset plate 29, and the projecting end is connected to the communication pipe 3.
5 are connected to each other in the longitudinal direction. Further, as described above, the middle part in the longitudinal direction of the communication pipe 35 is bent forward in a convex arc shape.

[0048] Therefore, in the vehicle body plan view, the communicating pipe 35 is an arcuate-shaped Hoboku, which, if above
The communication pipe 35 can be made shorter and the flow of the cooling water can be made more smooth as compared with the case where the communication pipe 35 has a U-shape that opens backward.

In particular, in FIG.
Each end of the communication pipe 35 has the above-described radiator 34,
34 are arranged.

In FIG. 1 and FIGS. 4 to 6, the engine 13 and the power transmission device 13a for the vehicle body frame 2 are shown.
The support configuration of will be described.

In FIGS. 1 and 2, the power transmission device 13a
Are supported by the pivot 21.

1 and 4, the front part of the crankcase 37 of the engine 13 is supported by the left and right rear tubes 25 by a first support member 38.

The first support member 38 includes left and right support pieces 39, 4
0, and the front end of the left support piece 39 is the left rear tube 2
5 is welded. The front end of the right support piece 40 is a pipe-shaped nut 41 welded to the right rear tube 25.
Are detachably screwed by a pair of bolts 42. Then, with the front part of the crankcase 37 sandwiched between the rear ends of the left and right support pieces 39 and 40, the bolt 4
3 screwed.

By the way, the left and right support pieces 39, 40
Before screwing with the bolt 43, in order to facilitate the fitting at the time of assembling with the front part of the crankcase 37,
The dimension between the support pieces 39 and 40 is slightly larger than the width dimension of the front part of the crankcase 37, and there is a slight play between the two.

For this reason, when the bolts 43 are screwed, each of the support pieces 3 is absorbed by the amount of the rattling.
Internal stress is generated at 9, 40.

At this time, the left support piece 39 is welded to the left rear tube 25, and since this weld has high rigidity, a large stress is likely to be generated in this weld. However, the right support piece 40 is attached to the right rear tube 25 by the bolt 4.
2 and is more easily bent, that is, lower in rigidity than the case of the left support piece 39.
Therefore, each support piece 3 is screwed with the bolt 43.
The stress that is going to be generated at 9, 40 is mainly absorbed by the right support piece 40, and it is prevented that a large stress is generated in the left support piece 39 of the welded structure.

In this case, even if the right support piece 40 is damaged by the stress, the bolt 42 can be used without replacing the entire body frame 2 with a new one.
And simply replacing the right support piece 40 with a new one is sufficient.

The support pieces 39 and 40 are attached to the rear tube 25 from the crankcase 37 side.
A bent portion 44 extending in the entire width direction is formed.

For this reason, the stress at the time of screwing by the bolt 43 is effectively absorbed by the bent portions 44, and the welded portion of the left support piece 39 to the rear tube 25 and the right support piece to the nut 41. The stress concentration is prevented from occurring at the screwed portion 40, and thus the engine 13 and the power transmission device 13a are lightly and firmly supported.

The bent portion 44 need not be provided.

In FIGS. 1 and 5, the rear lower portion of the crankcase 37 is supported by the left and right rear tubes 25 by a second support 46.

The second support 46 is connected to the first support 38.
Since the configuration is the same as that described above, the same reference numerals as those in the first support member 38 are attached to the drawings, and the description thereof is omitted.

The second support member 46 has a bent portion 44
Is not provided, but may be provided.

In FIG. 1 and FIG.
The rear end of the rear arm bracket 20, the front end of the rear arm bracket 20, and the rear end of the stay 27 are connected to each other by the engine 13
Is supported by the third support 50.

The third support member 50 includes left and right support pieces 51,
One end of each of the support pieces 51, 51 is screwed to the connecting portion 48 with a bolt 52, and the other end is screwed to the cylinder head 49 with a bolt 53.

The engine 13 and the power transmission device 13a are firmly supported by the body frame 2 by the pivot shaft 21 and the first to third support members 38, 46, 50 as described above.

[0067]

According to the present invention, there is provided a head pipe in which a body frame constitutes a front end portion of the head pipe for slidably supporting a front fork, a main frame extending rearward and downward from an upper portion of the head pipe, A down tube extending downward from the lower part of the head pipe toward the rear and a gusset plate that is erected at each front of the main frame and the down tube, and a fuel tank is arranged behind the head pipe. A radiator extending in the vertical direction is disposed near each of the left and right sides of the gusset plate, and each end in the longitudinal direction is connected to each of the radiators.
Flexible to connect each inside of these radiators
In the body structure of a motorcycle provided with a communication pipe of

1) When viewed from the side of the vehicle body,
Between the trailing edge of the gusset plate, to form through space penetrating in the width direction of the vehicle body, the communicating to penetrate the space
A pipe is provided.

For this reason, the head pipe,
Since the communication pipes do not need to be provided so as to bypass the rear part of the main frame, the front part of the down tube, and the outer edge of the combined body by the gusset plate, the communication pipes can be omitted.
The length of the pipe can be shortened, and the communication pipe can be made more linear.

Thus, the flow of the cooling water in the communication pipe can be made smooth.

[0071] 2) when the body is viewed from the side, than the radiator is disposed at least a portion of the communicating pipe <br/> front, or
The communication pipe is located above the radiator
I have.

A front fork is supported on the head pipe so as to be steerable. Usually, spaces for allowing the steering operation of the front fork are secured on the left and right sides of the head pipe. and, the space is to be positioned on the front side than the fuel tank and the radiator.

The space above the radiator
Is connected to the space in front of the radiator.
Therefore, a large space can be obtained by these two spaces.

[0074] Therefore, as described above, the radiator
Disposed at least a portion of the communicating pipe in front, or
The communication pipe is located above the radiator
And a and was, thus, "plumbing" of the communicating pipe is undisturbed respectively generally larger fuel tank and the radiator shape, the front of each radiator
From the upper side that Deki using the above-mentioned wide space.

Therefore, as described above, the radiator
Even in the case was due to be to facilitate the kicking flow of cooling water Unishi,
Since the above-mentioned wide space can be used , the above-mentioned "piping work " can be easily performed.

3) The communication pipe is placed halfway in the longitudinal direction.
The portion is bent forward to form a convex arc.

For this reason, the “piping work” of the communication pipe
, The left and right radiators are connected to each end of the communication pipe
When connecting, the distance between the left and right radiators
Angle of the above communication pipe even if there is an error
Can be easily absorbed.

Therefore, as described above, the radiator
Even if the cooling water flow is smooth
Each of the above radiators can be easily absorbed by the above errors.
"Piping work" of the communication pipe to the pipe can be easily performed.

As described above, the communication pipe is
Fold in such a way that the middle part in the longitudinal direction becomes a convex arc
That is, the middle of the communication pipe
Between the part of the space to be penetrated and the radiator
The connecting part at each end of the communication pipe is
Is deviated to

For this reason, each of the left and right gusset plates
Connect each end of the communication pipe to each radiator
In order to connect the parts, first,
When performing the work of penetrating the
The connecting part on the radiator side is
Is prevented from being in the way.

Therefore, also in this regard, the above radiators are
"Piping work" of the communication pipe can be easily performed.

4) Each end of the communication pipe in the longitudinal direction is
Tilt to the outside of the vehicle as it goes to the rear of the vehicle
It is inclined.

For this reason, in the plan view of the vehicle body, the communication pipe
Is shaped like a U-shaped arc.
Compared to the case where the communication pipe is
Ip flow can be shorter.

Therefore, also in this respect, the communication pipe is
Cooling water flow can be smoothed.

5) Each end of the communication pipe in a plan view of the vehicle body
The part is disposed so as to overlap the radiator.

For this reason, the communication pipe is as described above.
The middle part is a convex arc that protrudes forward.
However, as described above, each end of the communication pipe is
The radiator and the communication pipe correspond to the radiator
It is provided compactly in the front-rear direction.

Therefore, a communication pipe to each of the above radiators
In order to facilitate the “plumbing work” of
Generally speaking, there are radiators and communication pipes
Are preferably separated from each other by
The eta and the communication pipe tend to be large, as a whole
However, as described above, the communication pipe to each radiator
"Piping work" can be easily performed,
As described above, the radiator and the communication pipe are
There is an advantage that it is installed.

[Brief description of the drawings]

FIG. 1 is a partially enlarged view of FIG. 2;

FIG. 2 is an overall side view of the motorcycle.

FIG. 3 is a view taken in the direction of arrows 3-3 in FIG. 1;

FIG. 4 is a sectional view taken along line 4-4 in FIG. 1;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 1;

FIG. 6 is a sectional view taken along line 6-6 in FIG. 1;

[Explanation of symbols]

Reference Signs List 1 motorcycle (saddle-riding type vehicle) 2 body frame 4 front fork 13 engine 15 fuel tank 18 head pipe 19 main frame 23 down tube 29 gusset plate 32 space 34 radiator 35 communication pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B62J 39/00 B62K 11/02 B62K 19/30

Claims (1)

(57) [Claims] 1. A head pipe having a front end portion formed by a body frame and supporting a front fork so as to be steerable,
A main frame extending rearward and downward from an upper portion of the head pipe, a down tube extending rearward and downward from a lower portion of the head pipe, and a gusset plate erected at each front of the main frame and the down tube. Prepared,
It disposed the fuel tank to the rear side of the head pipe, with disposing the radiator extending in the upper and lower direction in the vicinity right and left side of the gusset plate, each end of the longitudinal
Is provided with a flexible communication pipe connected to each of the radiators and communicating the insides of the two radiators with each other. 1) The head pipe, between the trailing edge of the gusset plate, to form through space penetrating in the vehicle body width direction, and disposed the communicating pipe to penetrate the space, 2) when the body is viewed from the side, above the front side than the radiator Communicating
Disposed at least a portion of the passage pipe, and the communicating
The pipe is disposed above the radiator, and 3) the communicating pipe is formed such that a halfway portion in the longitudinal direction thereof projects forward.
4) Bend each end of the communication pipe in the longitudinal direction to the vehicle body.
5) Incline toward the outside of the vehicle body toward the rear. 5) When viewed from the top of the vehicle body, each end of the communication pipe is
The body structure of a motorcycle arranged to overlap the eta .