JP2013203125A - Vehicle body frame of motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle body frame of a motorcycle, which can improve riding comfort by facilitating a deflection of the whole vehicle body frame.SOLUTION: A vehicle body frame of a motorcycle includes: a head pipe (11), an upper pipe (22) which is extended out backward from an upper portion of the head pipe (11); a lower pipe (23) which is extended out backward from a lower portion of the head pipe (11); a plurality of connection pipes (24-27) which connect the upper and lower pipes (22) and (23) together; and an engine support portion (H3) which is provided on the lower pipe (23). All portions (24b-27b) for connecting the plurality of connection pipes (24-27) to the lower pipe (23) are provided in locations except the engine support portion (H3).

Description

  The present invention relates to a body frame of a motorcycle.

2. Description of the Related Art Conventionally, as a motorcycle body frame, for example, a motorcycle body frame as disclosed in Patent Document 1 is known. The motorcycle body frame includes a head pipe (7), an upper pipe (27) extending rearward from the top of the head pipe (7), and the head pipe (7). 7) a lower pipe (28) extending rearward from the lower part, a plurality of connecting pipes (29-31) connecting the upper pipe (27) and the lower pipe (28), and the lower pipe (28) And an engine support part (46) provided in the engine.
The lower ends of the connection pipes (30) and (31) are all connected to the lower pipe (28) in the engine support portion (46).

Japanese Patent Laid-Open No. 08-216960

In the above-described conventional motorcycle body frame, the lower ends of the connection pipes (30) and (31) are all connected to the lower pipe (28) in the engine support part (46). ) Increases in rigidity, and when the vehicle body is tilted, the force concentrates only on the engine support portion (46), making it difficult to bend the entire vehicle body frame.
The problem to be solved by the present invention is to provide a body frame of a motorcycle that can easily bend the entire body frame to enhance riding comfort.

In order to solve the above problems, the body frame of the motorcycle of the present invention is:
A head pipe, an upper pipe extending rearward from the upper portion of the head pipe, a lower pipe extending rearward from the lower portion of the head pipe, and a plurality of connecting pipes connecting the upper pipe and the lower pipe; In a motorcycle body frame provided with an engine support provided on the lower pipe,
All of the connecting portions of the plurality of connecting pipes with respect to the lower pipe are provided at portions other than the engine support portion.
According to the motorcycle body frame, since the connecting portions to the lower pipes of the plurality of connecting pipes are all provided at portions other than the engine support portion, the rigidity of the engine support portion is lowered and the vehicle body is inclined. When this happens, the force acting on the engine support part is easily dispersed to parts other than the engine support part. Accordingly, the entire body frame is easily bent, and the ride comfort can be enhanced.

The connecting pipes may be arranged so as to form a polygonal shape of a quadrangle or more with the upper pipe as an upper side and the lower pipe as a lower side in a side view.
With this configuration, since the connection portion between the upper and lower pipes and the connection pipe is not concentrated (distributed state), the force acting on the vehicle body frame is easily dispersed throughout the vehicle body frame. It becomes easier to bend more smoothly and ride comfort is further improved.
In addition, since the connecting portion between the upper and lower pipes and the connecting pipe is not concentrated, the connecting operation when the upper and lower pipes and the connecting pipe are connected by welding is facilitated. As a result, the connection accuracy is increased, and the accuracy of the entire body frame can be increased.

The upper ends of the plurality of connection pipes are all connected to the upper pipe without being connected to other connection pipes, and the lower ends of the plurality of connection pipes are all connected to other connection pipes. Without being connected to the lower pipe.
With this configuration, since the connection portion between the upper and lower pipes and the connection pipe is not concentrated (distributed state), the force acting on the vehicle body frame is easily dispersed throughout the vehicle body frame. It becomes easier to bend more smoothly and ride comfort is further improved.
In addition, since the connecting portion between the upper and lower pipes and the connecting pipe is not concentrated, the connecting operation when the upper and lower pipes and the connecting pipe are connected by welding is facilitated. As a result, the connection accuracy is increased, and the accuracy of the entire body frame can be increased.

A lower end of at least one of the plurality of connection pipes may be connected to the vicinity of the engine support portion of the lower pipe.
If comprised in this way, an engine support part to which the force from an engine acts can be aimed at dispersion | distribution, reinforcing efficiently with the said connection pipe.

When viewed from the axial direction of the head pipe, each of the upper pipe and the lower pipe has a widened portion extending obliquely rearward from the head pipe and a bent portion that bends relatively inward in the vehicle width direction at the rear end of the widened portion. A rear extension portion extending rearward through the portion,
In side view, at least one of the plurality of connecting pipes connects the vicinity of the bent portions of the upper pipe and the lower pipe, and the upper and lower connecting portions of the connecting pipe are It can be set as the structure arrange | positioned back and forth.
If comprised in this way, the ease of bending can also be ensured, ensuring the connection strength of an upper and lower pipe.
In order to ensure the connection strength of the upper and lower pipes, a structure in which the bent portions of the upper and lower pipes, the vicinity of the front side thereof, or the vicinity of the rear side thereof are connected by a connection pipe can be used. However, in such a structure, the presence of the connecting pipe makes it difficult for the distance between the upper and lower frames to be displaced, and as a result, the vehicle body frame is difficult to bend.
On the other hand, according to the present invention, the connection strength of the upper and lower pipes can be secured by connecting the vicinity of the bent portions of the upper pipe and the lower pipe, and at the same time, the upper and lower connection portions of the connection pipe are bent. By separating the front and rear, the distance between the upper and lower frames is easily displaced, and as a result, the body frame can be easily bent.

The lower pipe is provided with a hanging pipe that extends integrally and linearly downward from the rear extending portion in a substantially vertical direction, and a lower cylinder support that supports the engine below the cylinder at the lower portion of the hanging pipe. It can be set as the structure which provided the part.
If comprised in this way, since an engine can be supported so that it may hold from the cylinder downward direction by a drooping pipe, a shake of an engine can be decreased.
Moreover, since the drooping pipe extends integrally and linearly from the rear extension of the lower pipe, the body frame can be easily bent, and the drooping pipe extends in a substantially vertical direction downward. Can be made as short as possible.

The vehicle body frame includes a lower front support portion that supports the front portion of the engine below the crankshaft of the engine, and a lower rear support portion that supports the rear portion of the engine below the crankshaft of the engine. It can be configured.
If comprised in this way, since an engine can be supported by the lower front support part and a lower rear support part so that it may hold from the downward direction rather than a crankshaft, an engine shake can be decreased.

A cross member arranged in the vehicle width direction that connects the left and right rear extension portions between the left and right rear extension portions may be omitted.
If comprised in this way, while it becomes easy to displace the space | interval of right-and-left rear extension parts, it can make a vehicle body frame bend easily, and it becomes easy to utilize the space between right-and-left rear extension parts.

1 is a side view of a motorcycle using an embodiment of a body frame of a motorcycle according to the present invention. The side view which shows the head pipe 11, the main frame 20, and the pivot plate 30. FIG. FIG. 3 is a partially omitted rear view of FIG. 2. The figure which looked at FIG. 2 from the axial direction upper direction of the head pipe 11. FIG. The figure which showed the side surface and back surface which show an example of the joint member of a rear cushion simultaneously.

  Embodiments of a body frame of a motorcycle according to the present invention will be described below with reference to the drawings. In each figure, the same reference numerals are given to the same or corresponding parts.

  A motorcycle 1 shown in FIG. 1 has a body frame 10. The vehicle body frame 10 is provided at a head pipe 11 that rotatably supports a front fork 3 that rotatably supports a front wheel 2f, a main frame 20 that extends rearward from the head pipe 11, and a rear lower portion of the main frame 20. A pivot plate 30 that pivotally supports the swing arm 4 that pivotally supports the rear wheel 2r by a pivot shaft 4p, and a rear frame 40 that is provided obliquely rearward from the upper portion of the pivot plate 30. .

A prime mover (engine) 5 is disposed in front of the pivot plate 30, and the rear wheel 2r is driven by the prime mover 5 via the drive chain 5d.
The engine 5 is a V-type engine having a crankcase 5c, a forwardly inclined cylinder 5f provided obliquely upward and forward with respect to the crankcase 5c, and a backwardly inclined cylinder 5r provided obliquely upward and rearward with respect to the crankcase 5c. It is.

As shown in FIGS. 2 to 4, the main frame 20 includes an upper pipe 22 extending rearward from the upper part of the head pipe 11, a lower pipe 23 extending rearward from the lower part of the head pipe 11, and these upper pipes. A plurality of connection pipes (four in the figure, 24 to 27 in the figure) are provided to connect 22 and the lower pipe 23, and an engine support portion H <b> 3 is provided on the lower pipe 23.
And all the connection parts 24b, 25b, 26b, and 27b with respect to the lower pipe 23 of the some connection pipes 24-27 are provided in parts other than the said engine support part H3.

  According to the motorcycle body frame 10, since the connecting portions 24b to 27b with respect to the lower pipe 23 of the plurality of connecting pipes 24 to 27 are all provided at portions other than the engine support portion H3, At the same time, the rigidity is lowered, and the force acting on the engine support H3 when the vehicle body is tilted is easily dispersed to parts other than the engine support H3. Therefore, the entire body frame is easily bent, and the riding comfort of the motorcycle 1 can be enhanced.

The connection pipes 24 to 27 are arranged so as to form a quadrilateral or more polygonal shape with the upper pipe 22 as the upper side 22s and the lower pipe 23 as the lower side 23s in a side view (FIG. 2).
If comprised in this way, since it will be in the state (distributed state) where the connection part of the upper and lower pipes 22 and 23 and the connection pipes 24-27 does not concentrate, the force which acts on a vehicle body frame is easy to be disperse | distributed to the whole vehicle body frame. As a result, the entire body frame is more easily bent and the riding comfort is further improved.
In addition, since the connecting portions between the upper and lower pipes 22 and 23 and the connecting pipes 24 to 27 are not concentrated, the connecting operation when the upper and lower pipes 22 and 23 and the connecting pipes 24 to 27 are connected by welding is performed. It becomes easier to do. As a result, the connection accuracy is increased, and the accuracy of the entire body frame can be increased.
In FIG. 2, the encircled numbers indicate the number of polygonal corners formed by the connecting pipes 24 to 27, the head pipe 11, and the pivot plate 30 with the upper pipe 22 as the upper side 22 s and the lower pipe 23 as the lower side 23 s. Yes. That is, with the upper pipe 22 as the upper side 22s and the lower pipe 23 as the lower side 23s, the head pipe 11 and the connection pipe 24 form a square, the connection pipes 24 and 25 also form a square, and the connection pipes 25 and 26 form a pentagon. The connecting pipes 26 and 27 form a square, and the connecting pipe 27 and the pivot frame 30 also form a square.

The upper ends 24c, 25c, 26c, 27c of the plurality of connection pipes 24-27 are all connected to the upper pipe 22 without being connected to the other connection pipes 24-27, and the lower ends of the plurality of connection pipes 24-27. 24b, 25b, 26b, 27b are all connected to the lower pipe 23 without being connected to the other connecting pipes 24-27.
If comprised in this way, since it will be in the state (distributed state) where the connection part of the upper and lower pipes 22 and 23 and the connection pipes 24-27 does not concentrate, the force which acts on a vehicle body frame is easy to be disperse | distributed to the whole vehicle body frame. As a result, the entire body frame is more easily bent and the riding comfort is further improved.
In addition, since the connecting portions between the upper and lower pipes 22 and 23 and the connecting pipes 24 to 27 are not concentrated, the connecting operation when the upper and lower pipes 22 and 23 and the connecting pipes 24 to 27 are connected by welding is performed. It becomes easier to do. As a result, the connection accuracy is increased, and the accuracy of the entire body frame can be increased.

The lower end of at least one of the plurality of connection pipes 24 to 27 (the connection pipe 26 in the drawing) is connected to the vicinity of the engine support H <b> 3 in the lower pipe 23.
If comprised in this way, dispersion | distribution of a force can be aimed at, reinforcing the engine support part H3 to which the force from the engine 5 acts with the connection pipe 26 efficiently.

  As shown in FIG. 4, when viewed from the axial direction of the head pipe 11, the upper pipe 22 and the lower pipe 23 are respectively widened portions 22 b and 23 b extending diagonally rearward from the head pipe 11 and the widened portions 22 b and 23 b. It has rear extension parts 22d and 23d extending rearward through bent parts 22c and 23c that bend inward in the vehicle width direction at the rear end. 2 and 4, the hatched portion is a bent portion.

  As shown in FIG. 2, at least one of the plurality of connection pipes 24 to 27 (the connection pipe 25 in the drawing) is a bent portion 22 c of the upper pipe 22 and the lower pipe 23 in a side view. , 23c are connected to each other, and the upper and lower connecting portions 25c, 25b of the connecting pipe 25 are arranged so as to be distributed before and after the bent portions 22c, 23c. That is, the upper end 25 c of the connection pipe 25 is connected to the vicinity of the rear portion of the bent portion 22 c of the upper pipe 22, and the lower end 25 b of the connection pipe 25 is connected to the vicinity of the front portion of the bent portion 23 c of the lower pipe 23.

If comprised in this way, the ease of bending can also be ensured, ensuring the connection strength of the upper and lower pipes 22 and 23. FIG.
In order to secure the connection strength between the upper and lower pipes 22 and 23, a structure is employed in which the bent portions 22c and 23c of the upper and lower pipes 22 and 23, the front vicinity, or the rear vicinity are connected by a connection pipe 25. obtain. However, in such a structure, the presence of the connecting pipe 25 makes it difficult for the distance between the upper and lower frames 22 and 23 to be displaced, and as a result, the body frame is less likely to bend.
On the other hand, in this embodiment, the connection strength of the upper and lower pipes 22 and 23 can be secured by connecting the vicinity of the bent portions 22c and 23c of the upper pipe 22 and the lower pipe 23. By distributing the upper and lower connecting portions 25c and 25b of the pipe 25 to the front and rear of the bent portions 22c and 23c, the distance between the upper and lower frames 22 and 23 is easily displaced, and as a result, the vehicle body frame can be easily bent.

The rear pipe 23d of the lower pipe 23 is provided with a hanging pipe 28 that extends integrally and linearly downward from the rear extending section 23d in a substantially vertical direction. A cylinder 5f of the engine 5 is provided below the hanging pipe 28. A cylinder lower support portion H1 that supports the engine 5 is provided further below.
If comprised in this way, since the engine 5 can be supported so that it may hold from the cylinder downward direction by the drooping pipe 28, the shake of the engine 5 can be decreased.
Moreover, since the drooping pipe 28 extends integrally and linearly from the rear extension 23d of the lower pipe 23, it is possible to ensure the flexibility of the vehicle body frame, and the drooping pipe 28 extends downward substantially in the vertical direction. Therefore, the length of the hanging pipe 28 can be shortened as much as possible.
Reference numeral 29 denotes a reinforcing pipe for the hanging pipe 28.

The vehicle body frame 10 has a lower front support portion (in this embodiment, the cylinder lower support portion H1) that supports the front portion of the engine 5 below the crankshaft 5c1 of the engine 5, and a crankshaft 5c1 of the engine 5. A lower rear support portion H4 that supports the rear portion of the engine 5 is provided below.
With this configuration, the engine 5 can be supported by the lower front support part H1 and the lower rear support part H4 so as to be held from below the crankshaft 5c1, so that the vibration of the engine 5 can be reduced. it can.
The lower rear support portion H4 can be configured by a pivot shaft 4p that supports the swing arm 4 so as to be swingable.

As shown in FIG. 4, between the left and right rear extension parts 22d and 22d of the upper pipe 22 and between the left and right rear extension parts 23d and 23d of the lower pipe 23, the rear extension parts are connected to each other. A cross member arranged in the width direction is not provided.
With this configuration, it is possible to easily displace the space between the left and right rearward extending portions 22d and 23d to make the body frame bend easily, and use the space 20s between the left and right rearward extending portions. It becomes easy to do.
3 and 4, reference numeral 23 f denotes a cross pipe that connects the front portions of the widened portion 23 b of the lower pipe 23.

  2 to 4, the main frame 20 has left and right rear ends 21L and 21R, and left and right pivot plates 30L and 30R are respectively attached to the left and right rear ends 21L and 21R of the main frame 20. It is connected.

The left and right pivot plates 30L and 30R are connected to the upper connecting portion 32 to which the rear end 22r of the upper pipe 22 is connected, and to the rear end 23r of the lower pipe 23 with a space below the upper connecting portion 32, respectively. And a lower connecting portion 33.
The left and right upper connecting portions 32 are connected by an upper cross member 34, and the lower connecting portions 33 are connected by a lower cross member 35.

  With this configuration, the rear end 22r of the upper pipe 22 and the rear end 23r of the lower pipe 23 of the main frame 20 are connected to the upper connection portion 32 and the lower connection of the pivot plate 30 reinforced by the upper and lower cross members 34 and 35, respectively. Since it is connected to the portion 33 with a gap, a torsional force acting on the vehicle body frame 10 (for example, a torsional force acting around an axis perpendicular to the plane of FIG. 3 or the rear end of the main frame 20 in FIG. The moment acting on the periphery is distributed to the upper connecting portion 32 and the lower connecting portion 33. Therefore, it becomes easy to form the bend in the whole body frame 10, and the riding comfort of the motorcycle 1 can be enhanced.

  Further, in the motorcycle body frame described in Japanese Patent Application Laid-Open No. 08-21696 described above, the rear arm bracket did not contribute at all to the frame formed by the body frame in a side view. According to the embodiment, the rear end 22r of the upper pipe 22 of the main frame 20 and the rear end 23r of the lower pipe 23 are connected to the upper connection portion 32 and the lower connection portion 33 of the pivot plate 30 with a space therebetween. The pivot plate 30 contributes to the frame formed by the vehicle body frame 10 in a side view. Also from this point, it becomes easy to form the bending of the entire body frame 10, and the riding comfort of the motorcycle 1 can be enhanced.

As shown in FIG. 1, the motorcycle 1 includes a rear cushion 6 that swingably supports a swing arm 4 that supports a rear wheel 2r. The rear cushion 6 has a lower end connected to the swing arm 4 via a link mechanism (not shown) and an upper end connected to the vehicle body frame 10.
As shown in FIGS. 2 and 3, in this embodiment, the rear cushion 6 is supported by the upper cross member 34, and the upper cross member 34 and the lower cross member 35 are connected by the connecting member 36.

With this configuration, the support structure can be simplified by supporting the rear cushion 6 on the upper cross member 34, and at the same time, the force acting on the vehicle body frame 10 from the rear cushion 6 is applied to the upper cross member by the connecting member 36. 34 and the lower cross member 35 can be dispersed. Therefore, the entire body frame is more easily bent and the riding comfort is further improved.
Such an effect can be obtained even when the rear cushion 6 is supported by the lower cross member 35.

  An appropriate structure can be adopted as a connecting structure to the cross member (the upper cross member 34 in the drawing) at the upper part of the rear cushion. For example, as shown in FIG. 5, a rod 7r having a male screw formed at the upper end, a U-shaped connecting bracket 7b connected to the lower end of the rod 7r so as to be rotatable around the rod 7r, and the connection Using the joint member 7 having a pin 7p for connecting the upper portion of the rear cushion 6 to the metal fitting 7bb, the tip of the rod 7r is screwed to a boss portion 34b (FIG. 3) with a female screw hole provided in the cross member. The rear cushion 6 can be connected to a cross member (the upper cross member is shown).

As shown in FIG. 2, the straight line L <b> 2 connecting the upper connecting portion 32 and the lower connecting portion 33 is substantially parallel to the axis L <b> 1 of the head pipe 11 in a side view.
With this configuration, the frame formed by the head pipe 11, the upper pipe 22, the lower pipe 23, and the pivot plate 30 can be brought close to a rectangular parallelepiped, and the entire body frame can be flexed while ensuring strength. Easier to form.

As shown in FIGS. 2 to 4, the pivot plate 30 linearly connects the upper connecting portion 32 and the lower connecting portion 33. The linear connection portion is indicated by reference numeral 30s.
If comprised in this way, it will become easy to distribute the twisting force which acts on the vehicle body frame 10 to the pivot plate 30, and it will become easy to form the bending in the whole vehicle body frame.

As shown in FIGS. 3 and 4, the rear end 22r of the upper pipe 22 is bent and extended toward the inner side of the vehicle body, and the rear cushion 6 is supported by the upper cross member 34. 2 and 4, the hatched portion is a bent portion.
With this configuration, the distance between the rear ends 22r of the upper pipe 22 is reduced to improve the rider's footing ability sitting on the seat 8 (FIG. 1) of the motorcycle 1, while the upper cross member 34 is shortened to reduce the rear. It becomes easy to ensure the support strength of the cushion 6.

As described above, the upper cross member 34 is provided with the support portion 34b of the rear cushion 6, while the lower cross member 35 is provided with the support portion H2 of the engine 5 as shown in FIGS. ing.
If comprised in this way, the support of the rear cushion 6 and the support of the engine 5 can be disperse | distributed to the upper and lower cross members 34 and 35, and it becomes easy to form the bending in the whole vehicle body frame.
The support portion H2 can be composed of left and right brackets 35b, 35b provided integrally with the lower cross member 35.

The vehicle body frame 10 includes an engine support portion (the lower front support portion) H1 disposed at a front portion of the crankcase 5c and below the forward tilt cylinder 5f, and a rear portion of the crankcase 5c and below the rear tilt cylinder 5r. The engine support portion H2 is disposed.
With this configuration, the engine 5 can be supported by supporting the lower part of the cylinder before and after the crankcase of the engine 5 and covering the entire engine 5 with the vehicle body frame 10. Therefore, the protection function of the engine 5 can be enhanced.

As shown in FIGS. 1 and 2, the rearward tilting cylinder 5 r is disposed below the upper pipe 22 and ahead of the pivot plate 30 in a side view.
If comprised in this way, the protection function of the backward tilt cylinder 5r can be improved.

  As shown in FIG. 1, the rear frame 40 is a substantially Y-shaped frame having a seat rail 41 that supports the seat 8 and a support frame 42 that supports the seat rail 41 from below. 41, the tip 41c of the pivot plate 30 is mounted on the mounting portion 37 (see FIGS. 2 to 4), and the tip 42c of the support frame 42 is mounted on the mounting portion 38 of the pivot plate 30 (see FIGS. 2 to 4). It is fixed to the pivot plate 30 by being fastened and fixed by a nut (not shown).

  1 to 4, reference numerals 35 d and 35 d are mounting brackets for the fuel tank 9, and are provided integrally with the cross member 35. Reference numerals 26 d and 26 d denote cowl mounting brackets which are integrally provided on the connecting pipe 26.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be appropriately modified within the scope of the gist of the present invention.

  4: swing arm, 5: engine, 5c: crankcase, 5c1: crankshaft, 5f: forward tilt cylinder, 5r: backward tilt cylinder, 10: body frame, 11: head pipe, 20: main frame, 22: upper pipe , 23: Lower pipe, 22b, 23b: Spreading part, 22c, 23c: Bent part, 22d, 23d: Rear extension part, 24-27: Connection pipe, 24b-27b: Lower end (connection part for lower pipe), 24c- 27c: upper end, 28: hanging pipe, H1: cylinder lower support part (lower front support part), H3: engine support part, H4: lower rear support part.

Claims (8)

A head pipe (11), an upper pipe (22) extending rearward from the upper portion of the head pipe (11), a lower pipe (23) extending rearward from the lower portion of the head pipe (11), and Motorcycle body comprising a plurality of connecting pipes (24-27) for connecting the upper pipe (22) and the lower pipe (23), and an engine support (H3) provided on the lower pipe (23). In the frame,
The connection parts (24b-27b) with respect to the lower pipe (23) of the plurality of connection pipes (24-27) are all provided at parts other than the engine support part (H3). Body frame. In claim 1,
The connecting pipes (24 to 27) are arranged so as to form a quadrilateral or more polygonal shape with the upper pipe (22) as an upper side and the lower pipe (23) as a lower side in a side view. The body frame of a motorcycle. In claim 1 or 2,
The upper ends (24c to 27c) of the plurality of connection pipes (24 to 27) are all connected to the upper pipe (22) without being connected to other connection pipes, and the plurality of connection pipes (24 to 27). 27) The lower body (24b to 27b) of 27) is connected to the lower pipe (23) without being connected to other connecting pipes. In any one of Claims 1-3,
The lower end of at least one connection pipe (26) among the plurality of connection pipes (24 to 27) is connected to the vicinity of the engine support portion (H3) of the lower pipe (23). Body frame for motorcycles. In any one of Claims 1-4,
When viewed from the axial direction of the head pipe (11), the upper pipe (22) and the lower pipe (23) are respectively widened portions (22b, 23b) extending diagonally rearward from the head pipe (11). A rear extension portion (22d, 23d) extending rearward through a bent portion (22c, 23c) that bends relatively inward in the vehicle width direction at the rear end of the widened portion (22b, 23b);
In side view, at least one of the plurality of connection pipes (24 to 27) is connected to the vicinity of the bent portions (22c, 23c) of the upper pipe (22) and the lower pipe (23). A vehicle body frame for a motorcycle, wherein the upper and lower connecting portions (25c, 25b) of the connecting pipe (25) are arranged so as to be distributed before and after the bent portions (22c, 23c). . In claim 5,
A hanging pipe (28) extending integrally and linearly from the rear extending section (23d) in a substantially vertical direction downward is provided on the rear extending section (23d) of the lower pipe (23). A body frame for a motorcycle, wherein a lower cylinder support portion (H1) for supporting the engine (5) is provided below the cylinder (5f). In any one of Claims 1-6,
A lower front support part (H1) for supporting the front part of the engine (5) below the crankshaft (5c1) of the engine (5), and an engine (5) below the crankshaft (5c1) of the engine (5) And a lower rear support portion (H4) for supporting the rear portion of the motorcycle body frame. In any one of Claims 5-7,
Between the left and right rear extension parts (22d, 22 and 23d, 23d), cross members arranged in the vehicle width direction are provided for connecting the left and right rear extension parts (22d, 22 and 23d, 23d) to each other. A motorcycle body frame characterized by the absence of a motorcycle.

Images