JP2001063669A - Motorcycle - Google Patents

Abstract

(57) Abstract: A front frame including a head pipe for supporting a front wheel in a steerable manner, a pair of left and right main frames extending rearward and downward from the head pipe, and a rear frame connected to the front frame. In a motorcycle in which a body frame is formed and an engine is mounted on the front frame, the front frame of the body frame is configured to be compact and lightweight while reducing the number of assembly operations with a small number of parts. . A bracket (15) forming a part of a front frame (11) is connected to a pair of frame sides (15a) welded to the rear ends of both main frames (14), and a single frame (15) connecting the two frame sides (15a). The upper part of the engine is supported by both the main frames 14 and the brackets 15 by integrally casting with the cross pipe portion 15b.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a front frame having a head pipe for supporting a front wheel so as to be steerable, a pair of left and right main frames extending rearward and downward from the head pipe, and connected to the front frame. The present invention relates to a motorcycle in which a body frame is formed by a rear frame and an engine is mounted on the front frame.

[0002]

2. Description of the Related Art Conventionally, such a motorcycle has been already known, for example, from Japanese Patent No. 2587815, etc. In this motorcycle, a pair of right and left main frames extend downward from the rear ends of both main frames. The bracket members are welded respectively, and a pair of upper and lower cross members are welded between the upper and lower portions of both bracket members, respectively, and the front end of the rear swing arm that supports the rear wheel is located at the middle part in the vertical direction of both bracket members. The engine is supported by a pair of down tubes which are pivotally supported and connect the front portions of both main frames and the lower end portions of both bracket members, respectively, and the bracket members.

[0003]

However, in the motorcycle having the above-mentioned conventional structure, the front frame supporting the engine among the body frames not only increases in size and causes an increase in weight, but also constitutes the front frame. The number of parts to be used increases. Moreover, in addition to the welding process of welding each bracket member to both main frames, a welding process of welding a pair of upper and lower cross members to both bracket members is necessary, and in addition to this, a down tube is connected to the main frame and the bracket member. Since work is also required, the number of assembly work steps is increased.

The present invention has been made in view of such circumstances, and provides a motorcycle in which a front frame of a vehicle body frame is configured to be compact and lightweight while reducing the number of assembly operations with a small number of parts. The purpose is to do.

[0005]

In order to achieve the above object, the present invention provides a front frame including a head pipe for supporting a front wheel so as to be steerable, and a pair of left and right main frames extending rearward and downward from the head pipe. And a rear frame connected to the front frame, a vehicle body frame is formed, and in a motorcycle in which an engine is mounted on the front frame, a bracket forming a part of the front frame includes the two main frames. A pair of frame side portions respectively welded to the rear end, and a single cross pipe portion connecting the two frame side portions are integrally cast and formed, and the engine frame is mounted on the main frame and the bracket. The upper part is supported.

According to such a configuration, the upper portion of the engine is supported by the main frame and the bracket, so that the front frame of the body frame does not require the conventionally required down tube, and the pair of main frames is not required. And a bracket integrally having a pair of frame side portions and a single cross pipe portion, so that the front frame can be made compact while reducing the number of parts and reducing the weight of the front frame. it can. In addition, there is no need for a welding process to connect the two frame side parts with a cross pipe part, and there is no need to connect the down tube, which was required in the past, thus reducing the number of man-hours for assembling the front frame. It is.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described based on one embodiment of the present invention shown in the attached drawings.

1 to 5 show an embodiment of the present invention. FIG. 1 is a side view of a motorcycle, FIG. 2 is an enlarged side view of a part of an engine and a front frame, and FIG. 2 of 3
FIG. 4 is a sectional view of the main frame taken along line 4-4 in FIG. 2, and FIG. 5 is a sectional view taken along line 5-5 in FIG.

First, in FIG. 1, a body frame F of the motorcycle is a front frame 1 on which an engine E is mounted.
1 and a rear frame 12 joined to the rear end of the front frame 11.
A front fork 18 that supports the front wheel WF is steerably supported on a head pipe 13 provided at the front end of the vehicle 1. A bar handle 19 is connected to an upper end of the front fork 18.

The front frame 11 supports a multi-cylinder engine E in which a plurality of cylinders, for example, four cylinders are arranged in parallel in the width direction of the body frame F. An arm support member 21 is supported at a rear portion of the crankcase 20 of the engine E, and a rear swing arm 22 that supports the rear wheel WR.
Is pivotally supported by the arm support member 21 via a support shaft 23. A link mechanism 24 is provided between the arm support member 21 and the rear swing arm 22, and a rear cushion unit 25 is provided between the link mechanism 24 and a rear portion of the front frame 11.

The power from the output shaft 26 of the transmission incorporated in the engine E is transmitted to the rear wheels WR through the chain transmission means 27.
7 is a drive sprocket 2 fixed to the output shaft 26.
8, a driven sprocket 29 fixed to the rear wheel WR,
An endless chain 30 wound around the sprockets 28 and 29 is arranged on the left side of the engine E in a state facing forward in the traveling direction of the motorcycle.

Above the engine E, the front frame 11
And a fuel tank 31 supported at the front of the rear frame 12. The fuel tank 31 and the engine E
An air cleaner 32 is disposed therebetween, and a radiator 33 is disposed in front of the engine E.

A plurality of, for example, four exhaust pipes 35 connected to the cylinder head 34 of the engine E extend from the front side of the engine E, below the engine E, to the right side of the rear wheel WR. , Is connected to an exhaust muffler 36 disposed on the right side of the rear wheel WR.

The rear frame 12 includes a pair of left and right rear stays 37 extending rearward from the rear end of the front frame 11.
And the front frame 1 above the rear stays 37.
A pair of left and right seat rails 38 extending rearward from the rear end of the vehicle 1 and coupled to the rear ends of the rear stays 37.
A main seat 39 for seating a rider is supported by seat rails 38 behind the fuel tank 31, and a pillion seat 40 for seating a passenger is provided at a position away from the main seat 39 behind the seat rails 38. Supported by

The head pipe 1 in the front frame 11
The front of the vehicle body 3 is covered with a front cowl 42 made of synthetic resin. Both sides of the front part of the vehicle body are covered with a center cowl 43 made of synthetic resin connected to the front cowl 42. A lower cowl 44 made of synthetic resin and covering a portion arranged below the center cowl 43 is connected to the center cowl 43. Also front cowl 42
Mirrors 4 for rear confirmation
5 are attached.

A rear fender 46 that covers an upper part of the rear wheel WR is attached to the rear frame 12, and a front wheel WF is provided.
Is mounted on the front fork 18. Most of the rear frame 12 and the rear fender 46 are covered with a rear cowl 48.

In FIG. 2 to FIG.
Is composed of a head pipe 13, a pair of left and right main frames 14, 14 extending rearward and downward from the head pipe 13, and a bracket 15 connecting the rear ends of both main frames 14, 14. Both mainframes 1
A support stay 51 for supporting the air cleaner 32 is provided between the front portions of the air cleaner 32 and the support stay 51.
It also functions as a cross member that reinforces both main frames 14,14.

The main frame 14 is formed, for example, by molding a cast ingot of an aluminium alloy so as to have a hollow rectangular cross section by a conventionally known extrusion molding method. Ribs 52 for dividing the inside of the main frame 14 into a plurality of, for example, four,
53 and 54 are provided integrally.

A head cover 55, which is the upper end of the engine E, is located between the lower portions of the main frames 14, 14.
And a part of the cylinder head 34 are arranged. The two main frames 14, 14 have lower halves 14a, 14a which are substantially vertical on both sides of the head cover 55 and the cylinder head 34 during extrusion molding. It is formed so as to have a cross-sectional shape consisting of upper halves 14b, 14b bent from the upper ends of the lower halves 14a, 14a toward the vehicle center line C.

The main frames 14, 14 are subjected to bending after the completion of the extrusion molding, and the main frames 14, 14 are formed such that their longitudinal middle portions are curved outwardly convexly. .

The engine support member 57 is welded to the lower surface of the left main frame 14 in the longitudinal direction middle part, and the engine support member 58 is welded to the lower surface of the right main frame 14 in the longitudinal direction middle part. In addition, the lower rear rib 5 of each of the ribs 52 to 54 is provided at a lower rear portion of each of the main frames 14, 14 in order to avoid interference with the engine E.
Notches 56 are provided so that the bottom of the main frame 14 is located at the rear end of the rib 54. , 14 welded to the engine support member 5
At 7 and 58, the openings are respectively closed.

The engine support members 57 and 58 are disposed on both sides of the upper end of the engine E, and the head cover 55 and the cylinder head 34 of the engine E are fastened and supported by the engine support members 57 and 58, respectively.

The bracket 15 is disposed above the front end of a rear swing arm 22 that supports the rear wheel WR, and is welded to the rear ends of the two main frames 14, 14, respectively. And a single cross pipe portion 1 connecting between the frame side portions 15a, 15a.
5b are integrally formed and cast with an aluminum alloy or the like.

At the rear end of the front frame 11, that is, both frame side portions 15a, 15a of the bracket 15, attached plate portions 61, 61 for fastening the front ends of the two seat rails 38 in the rear frame 12 are provided. Are integrally provided so as to project upward, and the attached plate portions 62 for fastening the front ends of the rear stays 37 in the rear frame 12 are integrally provided so as to project rearward. .

A pair of connecting plate portions 63 for connecting the upper end of the rear cushion unit 25 are integrally provided on the cross pipe portion 15b of the bracket 15 so as to protrude rearward.

In FIG. 5, a pair of left and right hanger portions 64, 65 disposed on both sides of the vehicle body center line C are integrally provided below the frame side portions 15a, 15a of the bracket 15 so as to protrude downward. On the other hand, a boss portion 20a is provided on the rear upper portion of the crankcase 20 of the engine W so as to be interposed between the hanger portions 64 and 65.
The boss portion 20a has an enlarged head portion 70a that is relatively long in the axial direction on one end side, and the through bolts 70 that are inserted through both the hanger portions 64 and 65 and the boss portion 20a. And is supported by the vehicle body frame F.

A nut 74 screwed to the other end of the through bolt 70 is provided on the hanger portion 64 on the side where the chain transmission means 27 is disposed with respect to the body center line C (in this embodiment, on the left side of the vehicle body center line C). And a through hole 67 having a smaller diameter than the fitting hole 66 are provided coaxially so that the other end of the through bolt 70 can be inserted. Can be

The hanger portion 65 on the opposite side of the body center line C from the side where the chain transmission means 27 is disposed (in this embodiment, on the right side of the vehicle body center line C) is provided with an insertion bolt 70
An insertion hole 68 through which the enlarged diameter head 70a on one end side is inserted is provided coaxially with the fitting hole 66 and the insertion hole 67, and a slot 69 that opens downward through the inner surface of the insertion hole 68 is provided. Can be

A tightening bolt 73 capable of reducing the width of the slit 69 and reducing the diameter of the through hole 68 is screwed into the hanger portion 65. By tightening the tightening bolt 73, the inserting bolt 73 is inserted. The enlarged head 70 a of 70 can be pressed and held by the hanger portion 65.

Further, the boss 20a is provided with an insertion hole 75 coaxial with the fitting hole 66 and the insertion holes 67, 68. An insertion bolt 70 is provided between the boss 20a and the hanger 64. Cylindrical spacer 71 to be inserted
Is interposed. The insertion bolt 70 is inserted into the insertion holes 68 and 75, the spacer 71, and the insertion holes 67 and 66 from the hanger portion 66 side.
The insertion hole 75 has an outer diameter that cannot be inserted. Thus, the insertion hole 6 of the hanger portion 65
When the nut 74 is tightened until the enlarged diameter head 70a fitted into the boss 8 contacts the boss 20a, the axial position of the insertion bolt 70 with respect to the boss 20a is regulated.

Next, the operation of this embodiment will be described. The front frame 11, which forms the body frame F in cooperation with the rear frame 12, comprises a head pipe 13 for supporting the front wheels WF in a steerable manner, It comprises a pair of left and right main frames 14, 14 extending downward from the pipe 13 and a bracket 15 for connecting between the rear ends of the two main frames 14, 14. A pair of frame side portions 15a, 15a welded to the rear end, and both frame side portions 15a;
a and a single cross pipe portion 15b for connecting the portions 15a with each other. In addition, the upper portion of the engine E is supported by the main frames 14, 14 and the frame side portions 15a, 15a, and the front end of the rear swing arm 22 that supports the rear wheel WR is connected to the frame side portions 15a, 1a.
It is swingably supported by the engine E below 5a.

That is, since the upper portion of the engine E is supported by the main frames 14, 14 and the bracket 15, the front frame 11 of the vehicle body frame F does not require the conventionally required down tube, and the pair of main frames 14 , 14 and a pair of frame side portions 15a, 15
a and a bracket 15 which is a casting integrally having a single cross pipe portion 15b. The front frame 11 is made compact while reducing the number of parts and reducing the weight of the front frame 11. can do.
Moreover, a welding process for connecting the two frame side portions 15a, 15a with the cross pipe portion 15b is not required, and the connection work of the down tube, which is conventionally required, is unnecessary. It is possible to reduce. Further, the front end of a rear swing arm 22 that supports the rear wheel WR is swingably supported by the engine E,
Since the frame side portions 15a, 15a are arranged above the front end of the rear swing arm 22, the bracket 15 having the frame side portions 15a, 15a and the cross pipe portion 15b integrally can be formed by a relatively small mold. Casting is possible and casting cost can be reduced.

The main frame 14 has a lower half 14a which is substantially vertical on both sides of the upper end of the engine E, and an upper half 1 which is bent from the upper end of the lower half 14a toward the vehicle center line C.
4b, and is formed by extrusion, so that the upper half portion 14b of the main frame 14 is inclined toward the vehicle center line C. Therefore, a space for disposing the upper end of the engine E is secured between the lower portions of the left and right main frames 14 and 14 and the width between the upper portions of the two main frames 14 and 14 is narrowed, so that the body can be made compact. It is possible. Moreover, since the main frame 14 is formed by extrusion, the cross-sectional shape of the main frame 14 during extrusion is the same over the entire length in the longitudinal direction, and the rigidity of the main frame 14 does not decrease.

Further, of a pair of left and right hanger portions 64 and 65 provided on the bracket 15 of the body frame F and protruding downward from the bracket 15, the hanger portions 64 and 65 are arranged on the side opposite to the chain transmission means 27 with respect to the body center line C. The hanger portion 65 has an enlarged diameter head 7 at one end of a through bolt 70.
0a, and a slot 69 which opens downward through the inner surface of the insertion hole 68, and tightens the bolt to reduce the width of the slot 29 to reduce the diameter of the insertion hole 68. 73 is screwed. Moreover, a spacer 71 is interposed between the hanger 64 and the boss portion 20a, and the through bolt 70 is restricted in its relative position with respect to the boss portion 20a in the direction along the axis, so that the two hanger portions 64, 6 are formed.
5 and the boss 20a.

Therefore, the through bolt 70 is connected to the engine E
In the state where the relative position of the crankcase 20 with respect to the boss portion 20a is restricted and the boss portion 20a is inserted through both the hanger portions 64 and 65, the tightening bolt 73 is tightened so as to reduce the width of the slit 69. As a result, the enlarged diameter head 70a is pressed and held by the hanger portion 65 due to the reduced diameter of the insertion hole 68. As a result, the through bolt 70
Regardless of the accuracy of the width of the boss portion 20a in the direction along the axis and the accuracy of the spacing between the hanger portions 64 and 65, the body frame F and the engine E are integrated to make the engine E stronger. It can function effectively as a member. In addition, the hanger portion 65 provided with the slit 69 is provided with the chain transmission means 2 with respect to the vehicle center line C.
7, the chain transmission means 27
The relatively large load due to the arrangement of the slit 69
And the influence of the arrangement of the chain transmission means 27 does not affect the support strength of the engine E.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

[0037]

As described above, according to the present invention, the front frame can be made compact while the number of parts is reduced and the weight of the front frame is reduced. It is possible to reduce.

[Brief description of the drawings]

FIG. 1 is a side view of a motorcycle.

FIG. 2 is an enlarged side view of a part of an engine and a front frame.

FIG. 3 is a view as viewed in the direction of arrow 3 in FIG. 2;

FIG. 4 is a sectional view of the main frame taken along line 4-4 in FIG. 2;

FIG. 5 is a sectional view taken along line 5-5 in FIG. 2;

[Explanation of symbols]

 11 Front Frame 12 Rear Frame 13 Head Pipe 14 Main Frame 15 Bracket 15a Frame Side 15b Cross Pipe 22 Rear Swing Arm E: Engine F: Body frame WF: Front wheel WR: Rear wheel

Claims (1)

[Claims] 1. A front frame (11) comprising a head pipe (13) for steeringably supporting a front wheel (WF) and a pair of left and right main frames (14) extending rearward and downward from the head pipe (13). , The front frame (11)
A body frame (F) is constituted by a rear frame (12) connected to the vehicle, and a part of the front frame (11) in a motorcycle in which the engine (E) is mounted on the front frame (11). A pair of frame side parts (15a) welded to the rear ends of the main frames (14), respectively, and a single cross pipe part connecting between the frame side parts (15a). (15
b), and the upper part of the engine (E) is supported by the main frame (14) and the bracket (15).