JPH1159542A - Body structure of motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cross pipe to pass a pivot shaft through the front end part of a rear swing arm, and compatibly miniaturize a motorcycle body. SOLUTION: The lower end part of a center frame 12 is connected to the intermediate part of a frame lower cross pipe 30 to connect right and left lower frames 14 to each other, and a recessed part 32 is provided. Rear swing arm support parts 16 are provided between right and left and parts of the frame lower cross pipe 30 and right and left rear stays 15. A pivot part cross pipe 41 connected between the front end parts of right and left arm parts 40 to constitute a rear swing arm 18 is arranged across the center frame in an approximately cruciform manner so as to be opposite to the recessed part 32, and supported on a pivot shaft 17 supported on the right and left swing arm support parts 16 in a piercing manner. A reserve tank 50 is arranged in a void part 43 formed between the pivot part cross pipe 41 of the rear swing arm 18 and a rear swing arm cross member 42.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body structure of a motorcycle in which one main frame and a center frame are provided along the center of the vehicle body, and more particularly to a custom wind motorcycle equipped with a two-cycle engine. Regarding the preferred ones.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 9-95279 discloses a main frame extending rearward from a head pipe that supports a front wheel so as to be steerable above an engine, and a rear end of the engine continuously extending from the rear end. A center frame extending downward through each is provided substantially along the center of the vehicle body, and a pivot shaft penetrating in the left-right direction is supported at a lower end portion of the center frame, and a rear swing arm is provided via this pivot shaft. FIG. 1 shows a vehicle body structure of a motorcycle in which respective front ends of left and right arm portions are supported, and a rear wheel is supported by a rear end of a rear swing arm.

[0003]

In the case of the above-mentioned vehicle body structure,
Since the body frame is simplified, the body can be made compact and lightweight, and a space for arranging accessories such as auxiliary equipment can be easily secured under the seat. This is suitable for a custom wind motorcycle equipped with a two-cycle engine in which a chamber is arranged.

In addition, if a rear swing arm structure in which the front ends of the left and right arms constituting the rear swing arm are not separated from each other as in the above-described conventional example but are connected and integrated by one pivot cross pipe, Further, the manufacturing is easy and the cost is low.

By the way, if such a pivot cross pipe is employed, the pivot cross pipe must be disposed so as to be shifted rearward so as not to interfere with the lower portion of the center frame. Will be shorter. However, the length of the rear swing arm is naturally limited, and cannot be simply shortened. As a result, the above-described compactness and weight reduction of the vehicle body cannot be achieved at the same time. It will be reduced.

In view of the above, the present invention does not reduce the length of the rear swing arm, achieves both compactness and light weight of the vehicle body, and provides a sufficient space for placing articles under the seats, despite the adoption of the pivot cross pipe. The purpose is to provide a body structure that can be secured.

[0007]

According to a first aspect of the present invention, there is provided a motorcycle having a vehicle body structure in which a front pipe is steered freely from a head pipe passing above an engine. And a center frame extending downward from the rear end of the main frame through the rear of the engine along the center of the vehicle body, and the front end is pivotally supported via a pivot shaft at the rear of the engine. In a motorcycle provided with a rear swing arm that supports a rear wheel at a rear end, the rear swing arm has a pair of left and right arms, and a front part of each arm is connected by a pivot cross pipe. Then, the pivot pipe having a length substantially equal to the width of the vehicle body passes through the pivot section cross pipe so as to cross the center frame in a substantially cross shape, The pivot portion to form a concave portion cross pipe intersect, characterized in that to face the intersection of the pivot portion cross pipe into the recess.

Here, the main frame and the center frame may be a single member that is formed continuously and integrally, or may be formed separately, and the rear end of the main frame and the upper end of the center frame are connected by welding or the like. May be done.
When the main frame and the center frame are formed continuously and integrally, a portion passing above the engine with the bent portion as a boundary is referred to as a main frame, and a portion passing vertically behind the engine is referred to as a center frame.

In the first invention, when the rear swing arm includes a rear swing arm cross member connecting the left and right arms behind the pivot cross pipe, the rear swing arm cross member and the pivot cross are provided. Auxiliary equipment can be arranged between the pipes, so that the space between the rear swing arm cross member and the pivot cross pipe can be effectively used, and especially the auxiliary equipment has a large capacity. In the case of the liquid container, the arrangement space is advantageous and the mass can be concentrated.

[0010] The second invention is the above-mentioned first invention, wherein:
A pair of left and right down frames extending downward from the head pipe through the front of the engine, a pair of left and right lower frames extending rearward below the engine from the lower ends of these down frames, and a rear end of each lower frame A lower frame cross member for connecting the lower frame cross member between the lower frame cross member and the lower end of the center frame. A pair of left and right rear swing arm supports connected to the protruding center frame cross member are provided, and the left and right rear swing arm supports support both ends of the pivot shaft.

Also in this case, the down frame and the lower frame may be a single member formed continuously and integrally, or each may be formed separately and the lower end of the down frame and the front end of the lower frame are connected by welding or the like. May be done. When the down frame and the lower frame are formed continuously and integrally, a portion that passes in the vertical direction in front of the engine with the bent portion as a boundary is defined as a down frame, and a portion that passes below the engine is defined as a lower frame.

[0012]

According to the first aspect of the present invention, the front ends of the left and right arms are connected by a pivot cross pipe for passing a pivot shaft, and the center frame and the pivot cross pipe intersect substantially in a cross shape. In addition, a recess is formed at the intersection of the pivot cross pipe of the center frame, and the intersection of the pivot cross pipe faces the recess, so that it interferes with the center frame despite crossing the center frame. This allows the pivot cross pipe to be positioned forward without the need to do so.

Therefore, despite the adoption of the pivot cross pipe, it is possible to reduce the length of the rear swing arm, reduce the size and weight of the vehicle body, and secure a sufficient space for disposing articles under the seat. In addition, since a single pivot cross pipe can be connected through a common pivot shaft, the structure of the pivot portion is simplified and assembly is facilitated.

According to the second aspect of the present invention, the rigidity of the vehicle body is increased by connecting the rear ends of the left and right lower frames and the lower end of the center frame with the lower frame cross member. A rear swing arm support portion is provided at both ends, and the pivot shaft can be supported by using the rear swing arm support portion. Therefore, the support portion of the pivot shaft can be easily provided, and the support span of the pivot shaft is sufficiently long, and the pivot shaft is supported. Since the cross pipe and the pivot shaft are sufficiently long, the torsional rigidity is increased.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view taken along the center of the body of a main portion near a pivot portion of a rear swing arm of the motorcycle according to the present embodiment, FIG. 2 is a left side view of the entire motorcycle, and FIG. FIG. 4 is a plan view of a portion corresponding to FIG. 1, FIG. 4 is a left side view of the vehicle body frame, and FIG.

First, the overall structure of the motorcycle will be outlined with reference to FIG. This motorcycle has a long wheel base in which a front fork 1 is greatly inclined, and a front wheel 2
The engine 4, the teardrop-shaped fuel tank 5, and the seat 6 are arranged at a low position between the rear wheels 3, and the seat position is configured to have a low appearance of an American type or Cactum motorcycle.

The upper portion of the front fork 1 that supports the front wheel 2 is greatly inclined rearward, and the upper portion is connected to the head pipe 1 via a bottom bridge 7 and a top bridge 8.
It is supported rotatably to zero.

After the handlebar 9 attached to the top bridge 8 has been extended greatly upward once, the grip portions 7 at both ends thereof are directed downward, so that the handlebar 9 has a handle shape common to American type or Cactum bikes. .

As is apparent from FIG.
0 is attached to the front end of the main pipe 11 along the vehicle body center line.
Center frame 1 gently extending obliquely downward from the rear, bending at its rear end, and continuously extending substantially vertically
It is 2. These are constituted by one continuous pipe member.

From the lower left and right of the head pipe 10, a pair of right and left down frames 13 extend obliquely downward, and their lower ends are connected to a lower frame 14 extending substantially horizontally in the front-rear direction. Rear stays 15 extend diagonally upward and rearward from the portion in a left-right pair. The down frame 13, the lower frame 14, and the rear stay 15 are each formed of a single pipe member that is continuous to the left and right.

A substantially triangular press-formed plate-shaped rear swing arm support portion 16 for connecting between the rear portions of the left and right lower frames 14 and the lower portion of the rear stay 15.
Are provided in pairs on the left and right sides of the vehicle body, and both ends of one pivot shaft 17 having a length substantially equal to the width of the vehicle body are supported at respective center portions thereof. Rear swing arm support 16
Can be appropriately structured such as a box shape or a cast product.

A rear swing arm 18 whose front end is pivotally supported by a rear swing arm support portion 16 extends rearward through the pivot shaft 17, supports the rear wheel 3 at its rear end, and connects the pivot shaft 17 to the rear swing arm. It is swingable in the vertical direction about the center, and constitutes a rear wheel suspension together with the shock absorber 19.

The seat rail 20 supporting the seat 6 is
A pair of left and right pipe members extending diagonally downward from the rear end of the main frame 11 to the rear. The upper parts of the left and right rear stays 15 are connected to the middle part thereof, and the upper end of the shock absorber 19 is supported near this connection part. The lower end of the grab rail 21 protruding upward from the rear end of the sheet 6 is supported at the rear end.

Main frame 11, center frame 1
2, the down frame 13 and the lower frame 14 constitute a front portion of the vehicle body frame having a substantially loop shape in a side view, and the engine 4 is supported in the loop space.

The engine 4 is of a water-cooled two-cycle type.
A cylinder cover with an air-cooled fin-like shape on the left and right sides of the cylinder part is formed to look like an air-cooled four-cycle engine. 22.

The upper part of the cylinder cover 22 and the fuel tank 5
Auxiliary equipment covers 23 are attached to the left and right between the lower parts of
The left and right accessory covers 23 are formed of resin and plated with silver, and cover up to the upper side surfaces of the cylinder cover 22 located below the fuel tank 5 so that they look like a metallic air cleaner. It has an appearance.

The engine 4 is sucked from an air cleaner covered by a side cover 25 via a carburetor 24, and is exhausted through an exhaust pipe 26, an exhaust chamber 27 and a silencer 28 disposed on the right side of the vehicle body. Reference numeral 29 denotes a radiator.

As is apparent from FIGS. 4 and 5, a lower frame cross member 30 composed of a pipe member is provided between the rear ends of the left and right lower frames 14, and a center is provided at an intermediate portion of the lower frame cross member 30. The lower end of the frame 12 is connected. Lower frame cross member 3
Numeral 0 is formed from a pipe or box-shaped press member.

A reserve tank mounting stay 31 is provided at the lower end of the center frame 12 near the connection with the lower frame cross member 30 so as to protrude rearward. The stay 31 is open upward and protrudes rearward. A recess 32 is formed above the recess 32, and a center frame cross member 33 of a pipe member that extends through the center frame 12 in the left-right direction is provided above the recess 32.

The left and right ends of the center frame cross member 33 are respectively connected to the left and right rear swing arm support portions 16.
The lower and rear portions of each of the rear swing arm support portions 16 are welded to the lower frame 14 and the rear stay 15. At the center of each rear swing arm support portion 16, a frame-side pivot portion 34 is formed in which the outer surface side forms a concave portion facing the inside of the vehicle body and the inner surface side projects cylindrically inwardly of the vehicle body.

The center frame cross member 33 does not necessarily extend right and left on a straight line, but may be a member extending vertically and communicating between the lower frame cross member 30 and the lower frame 14 while extending laterally. Further, it is formed of a pipe or box-shaped press member or the like.

A through hole for passing the pivot shaft 17 is formed in the center of the frame-side pivot portion 34, respectively.
The left and right frame-side pivot portions 34 provide the pivot shaft 1
7 are supported, and a recess 32 is formed near the position of the center frame 12 where the pivot shaft 17 intersects at this time (see FIG. 5).

A stay 35 is provided above the center frame 12 in the vicinity of the seat rail 20, and a water supply nozzle 36 is supported by the stay 35 as shown in FIGS. The water supply nozzle 36 has a water supply port directed outward of the vehicle body, and a cap 37 is attached thereto. In addition, engine hangers 38 and 39 are provided at respective intermediate portions of the lower frame cross member 30 and the center frame cross member 33.

As is apparent from FIGS. 1 and 3, the rear swing arm 18 has a pair of left and right arm portions 40 extending in the front-rear direction, and each front end thereof is connected to a pivot cross pipe 41 provided in the left-right direction. A rear swing arm cross member 42 connects the rear intermediate portion of the pivot section cross pipe 41 with a space therebetween while being welded.

A space 43 is formed between the pivot cross pipe 41 and the rear swing arm cross member 42.
A relatively large-diameter exhaust chamber 27 (FIG. 2) is provided in a space below the space 43, and a space for arranging articles in this portion is compressed.

Bearings are respectively mounted on the left and right ends of the pivot section cross pipe 41. The pivot section cross pipe 41 is connected to the left and right frame side pivot sections 3
The four pivot shafts 34 are arranged concentrically with the pivot shaft holes of the frame-side pivot portions 34, and the end of the pivot shaft 17, which has a long bolt shape from one of the frame-side pivot portions 34, is passed through the pivot-portion cross pipe 41 and the other end. Frame side pivot part 3
4, and a nut 44 (FIG. 3) is fastened to this protruding end.

As a result, the pivot section cross pipe 41
Are supported by left and right rear swing arm support portions 16, and the rear swing arm 18 is vertically swingable about a pivot shaft 17 that is bearing-supported at both left and right ends of a pivot cross pipe 41.

At this time, the pivot cross pipe 41 intersects the center frame 12 in a substantially cross shape as shown in FIG. 1 and cuts into the vicinity of the axis of the center frame 12. Since it is formed along the intersection of the pivot part cross pipe 41, the pivot part cross pipe 41 faces into the recess 32,
Interference with the center frame 12 is avoided.

A reserve tank 50 for supplying water to the radiator 29 is provided in the space 43, and the bottom is supported by inserting a pin 51 projecting downward into a hole formed in the stay 31. The part is fixed by fastening a mounting projection 52 projecting upward to a lower side surface of the battery holder 54 with a bolt 53.

A drain pipe 55 is provided at an upper part of the reserve tank 50, and a water supply side joint pipe 56 is provided at a lower middle part in a vertical direction, and is connected to a water supply nozzle 36 via a hose 57. A water supply-side joint pipe 58 is provided at a lower part, and is connected to the radiator 29 by a hose (not shown).

The bottom of the battery holder 54 is
The seat portion 63 is attached to a stay 60 (FIG. 3) projecting from the seat rail 5, the upper portion is attached to a stay 62 projecting from a cross plate 61 provided between the left and right seat rails 20, and the attachment projection 52 is attached to the side surface. And a battery 64 (FIG. 1) is housed therein.

The article placement space 65, which is substantially triangular in side view and surrounded by the center frame 12, the left and right seat rails 20 and the rear stay 15, is provided with the reserve tank 50 and the battery 64, which are auxiliary equipment. An air cleaner 66 is provided to avoid interference, and is attached to stays 67 to 69 protruding from the rear stay 15 and the seat rail 20.

Next, the operation of the present embodiment will be described. The front ends of the left and right arm portions 40 constituting the rear swing arm 18 are connected by a pivot cross pipe 41 for passing the pivot shaft 17, and the center frame 12 and the pivot cross pipe 41 intersect in a substantially cross shape. At the same time, the pivot pipe cross pipe 4 of the center frame 12
The cross section of the pivot section cross pipe 41 faces the recess 32 so that the pivot section cross pipe 41 faces the center frame 1.
The pivot portion can be located forward without interfering with the center frame 12 despite intersecting with the center frame 2.

Therefore, the pivot pipe 41
Despite the adoption of, the rear swing arm length is not shortened, the compactness and the weight reduction of the vehicle body are compatible, and a sufficient article arrangement space 6 below the seat 6 is provided.
5 can be secured. In addition, since a single pivot section cross pipe 41 can be connected through the common pivot shaft 17, the structure of the pivot section is simplified and the assembly is facilitated.

In addition, by connecting each rear end of the left and right lower frames 14 and the lower end of the center frame 12 by a lower frame cross member 30, the rigidity of the vehicle body is increased, and the left and right ends of the lower frame cross member 30 are increased. Is provided with a rear swing arm support portion 16 and the pivot shaft 17 can be supported by using the rear swing arm support portion 16. Therefore, the support portion of the pivot shaft 17 can be easily provided, and the support span of the pivot shaft 17 is sufficiently long. Further, since the pivot cross pipe 41 and the pivot shaft 17 are sufficiently long, the torsional rigidity is also increased.

The rear swing arm 18 forms a space 43 between the pivot cross pipe 41 and a rear swing arm cross member 42 provided behind the pivot pipe 41. A reserve tank 50 is formed in the space 43. With this arrangement, the space 43 between the pivot cross pipe 41 and the rear swing arm cross member 42 can be effectively used. Installation is easy. In addition, since it can be arranged relatively close to the center of gravity of the vehicle body and at a low position, the mass can be concentrated and the center of gravity can be reduced.

The present invention is not limited to the above-described embodiment, but can be variously modified. For example, the article placement space 65
A known auxiliary device other than the embodiment can be disposed in the. However, the auxiliary equipment provided in the cavity 43 is relatively heavy, especially a liquid container, and there is an oil tank as another example.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a main part of a motorcycle according to an embodiment of the present invention along the center of the vehicle body.

FIG. 2 is a left side view of the entire motorcycle to which the present invention is applied.

FIG. 3 is a perspective plan view of a portion corresponding to FIG. 1;

FIG. 4 is a left side view of the entire body frame.

FIG. 5 is a view showing the vehicle body frame from the rear side of the vehicle body;

[Explanation of symbols]

4: Engine, 10: Head pipe, 11: Main frame, 12: Center frame, 13: Down frame, 14: Lower frame, 15: Rear stay, 16: Rear swing arm support, 17: Pivot shaft, 18: Rear swing Arm, 30: frame lower cross pipe,
32: recess, 33: center frame cross member, 4
0: arm part, 41: pivot part cross pipe, 42:
Rear swing arm cross member, 43: Empty space, 5
0: Reserve tank (auxiliary equipment), 65: Space for arranging goods

Claims (3)

[Claims] 1. A main frame 11 extending rearward from a head pipe 10 that supports a front wheel 2 so as to be steerable through an upper part of an engine 4 and a rear end of the main frame 11 passing rearward of the engine 4 to a lower part. And a center frame 12 extending substantially along the center of the vehicle body, and a rear swing arm 18 having a front end supported by a pivot shaft 17 at the rear of the engine and supporting the rear wheel 3 at a rear end. In the wheel, the rear swing arm 18 has a pair of left and right arm portions 40.
Are connected by a pivot cross pipe 41 to the center frame 12 through a pivot shaft 17 having a length substantially equal to the width of the vehicle body.
The recess 3 is formed at the intersection of the pivot pipe cross pipe 41
A vehicle body structure for a motorcycle, characterized in that a cross section of the pivot cross pipe 41 faces the recess 32. 2. The rear swing arm 18 includes a rear swing arm cross member 42 for connecting the left and right arms 40 behind the pivot cross pipe 41, and the rear swing arm cross member 42 and the pivot cross pipe 41. The body structure of a motorcycle according to claim 1, wherein auxiliary equipment (50) is disposed in the space 43 between the two. 3. A pair of left and right down frames 1 extending downward from the head pipe 10 through the front of the engine 4.
3, a pair of left and right lower frames 14 extending rearward from the lower ends of the down frames 13 below the engine 4 and between the rear ends of the lower frames 14 and the lower end of the center frame 12, respectively. And a lower frame cross member 30 connected to the lower frame cross member 30. The center frame cross member protrudes upward from the lower frame 14 near both ends in the longitudinal direction of the lower frame cross member 30 and extends left and right from an intermediate portion of the center frame 12. A pair of left and right rear swing arm supports 16 are connected to the left and right rear swing arm supports 1.
The body structure of a motorcycle according to claim 1, wherein both ends of the pivot shaft (17) are supported by (6).