JP2015047982A - Vehicle body frame of motor cycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure the strength and rigidity of connection portions between a main frame and right and left side frames while avoiding increase in the number of components and increase in weld lengths and keep high accuracy in the relative positions of suspension members supporting an engine unit.SOLUTION: In a structure in which left and right side frames 6L, 6R are connected to the rear end of a main frame 3, a bracket 15 is joined to upper portions 6La, 6Ra of the side frames 6L, 6R and to the rear end of the main frame 3. The bracket 15 has left and right suspension parts 16L, 16R which are suspended forward and downward from the lower faces of the upper portions 6La, 6Ra of the respective side frames 6L, 6R, and a plate-shaped coupling member 17 coupling the upper edges of the left and right suspension parts 16L, 16R each other.

Description

  The present invention relates to a body frame of a motorcycle including a main frame and left and right side frames coupled to a rear end portion of the main frame.

  As a body frame of a motorcycle, for example, Patent Document 1 discloses a head pipe, a single main frame (backbone frame) extending rearward from the head pipe along the center of the body, and a girder attached to a rear end portion of the main frame. A configuration having a single down frame extending obliquely downward along the center of the vehicle body from the frame and the head pipe is disclosed. The cross beam frame is formed by connecting both ends of an upper cross pipe and a lower cross pipe arranged in the vehicle width direction with a pivot frame, and the upper cross pipe and the rear main frame portion of the main frame are connected orthogonally.

JP 2011-11599 A

  In the vehicle body frame disclosed in Patent Document 1, the end portion of the main frame is welded to the upper cross pipe disposed in the vehicle width direction. In the case of reinforcing the joint portion between the main frame and the upper cross pipe, a configuration using a reinforcing member as a separate member is conceivable. In this case, however, the number of parts increases and the weld length increases.

  Further, a pair of left and right engine hangers are provided at both axial ends of the upper cross pipe. High accuracy is required for the relative position of the pair of left and right engine hangers. However, if the engine hanger is welded to the upper cross pipe as separate left and right parts, it is easily affected by welding distortion and high accuracy cannot be maintained. There is.

  The present invention has been made in view of the above points, and in the structure in which the left and right side frames are coupled to the rear end portion of the main frame, while avoiding an increase in the number of parts and an increase in welding length, It is an object of the present invention to ensure the strength and rigidity of the joint portion with the left and right side frames and to maintain high accuracy of the relative position of the suspension member that supports the engine unit.

A motorcycle body frame of the present invention is a motorcycle body frame including a main frame extending rearward from a head pipe and left and right side frames coupled to a rear end portion of the main frame, The side frame has a structure in which an upper portion thereof is curved inward in the vehicle width direction and is abutted against and joined to a side surface of a rear end portion of the main frame, and an engine unit is supported on the upper portion of each side frame. A suspension member is provided.
Another feature of the body frame of the motorcycle according to the present invention is that it has an integral shape in which the upper edges of the left and right suspension members are connected by a connecting member. In this case, it is preferable that the left and right suspension members and the connecting member, which are integrally formed, are welded to upper portions of the left and right side frames and a rear end portion of the main frame.

  According to the present invention, in the structure in which the left and right side frames are coupled to the rear end portion of the main frame, the strength of the coupling portion between the main frame and the left and right side frames is reduced while avoiding an increase in the number of parts and an increase in weld length. The rigidity can be ensured and the accuracy of the relative position of the suspension member that supports the engine unit can be kept high.

1 is a left side view of a motorcycle as an application example of the present invention. It is a left view of the body frame concerning an embodiment. It is the perspective view seen from the right front of the body frame concerning an embodiment. It is a perspective view which shows the state which mounted the engine unit in the vehicle body frame which concerns on embodiment. It is a left side enlarged view showing the state where the engine unit is mounted on the body frame according to the embodiment.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 is a left side view of a motorcycle 100 as an application example of the present invention. First, the overall configuration of the motorcycle 100 will be described with reference to FIG. In the present application, up, down, left and right, and front and rear refer to directions viewed in the state of riding the motorcycle 100. In each drawing, the front is indicated by an arrow Fr, the rear by an arrow Rr, and the right by an arrow R. The left side is indicated by an arrow L.

  The motorcycle 100 is configured by forming a vehicle body skeleton by a vehicle body frame 1 made of steel or aluminum alloy and mounting various parts on the vehicle body frame 1. Details of the body frame 1 will be described later. The engine unit 101 is supported by the vehicle body frame 1 at a substantially central portion of the vehicle body.

  A steering head pipe 2 constituting the vehicle body frame 1 supports a front fork 102 so as to be rotatable. A handle bar 103 is coupled to the upper end side of the front fork 102. A front wheel 104 is rotatably supported on the lower end side of the front fork 102. The upper part of the front wheel 104 is covered with a front fender 105.

  A rear fork (swing arm) 106 that can swing in the vertical direction via a pivot shaft is supported by the vehicle body frame 1 behind the engine unit 101, and a rear wheel 107 is rotatable at the rear end of the rear fork 106. Supported. A shock absorber 108 is mounted between an appropriate position in the front and rear intermediate portion of the rear fork 106 and the vehicle body frame 1. An upper portion of the rear wheel 107 is covered with a rear fender 109, and a seat 110 on which a rider sits is disposed above the rear wheel 107. A fuel tank 111 is mounted on the front side of the seat 110.

  In this example, the engine unit 101 is an air-cooled four-cycle single-cylinder (two or more cylinders) engine. In the basic configuration of the engine unit 101, detailed description is omitted, but a crankcase 101A that rotatably supports and accommodates a crankshaft horizontally disposed in the left-right direction is coupled to an upper portion of the crankcase 101A, and its axis is It includes a cylinder 101B that is appropriately tilted forward and set in a substantially vertical direction, a cylinder head 101C that is coupled to the upper part of the cylinder 101B, and a cylinder head cover 101D that covers the cylinder head 101C. An exhaust pipe 115 connected to the cylinder head 101C is curved so as to pass through the lower part of the engine unit 101 and extends rearward of the vehicle body, and is coupled to the muffler 116.

  As for the vehicle exterior, various vehicle body covers such as the shroud 112 and the side cover 113 and the rear cover 114 disposed near the upper outside of the cylinder head 101C and the cylinder head cover 101D as shown in FIG. To wear.

Hereinafter, the configuration of the body frame 1 will be described.
As shown in FIGS. 2 and 3, a main frame (backbone frame) 3 is coupled to the steering head pipe 2. The main frame 3 extends rearward and obliquely downward and curves downward along the way. Further, the down frame 4 is coupled to the steering head pipe 2. The down frame 4 extends rearward and obliquely downward. A reinforcing frame 5 is disposed between the main frame 3 and the down frame 4.

The left and right side frames 6L and 6R are coupled to the rear end of the main frame 3. As shown in FIG. 3, the side frames 6L and 6R extend in a substantially vertical direction, and the upper portions 6La and 6Ra are curved inward in the vehicle width direction so as to abut against the side surface of the rear end portion of the main frame 3. It has a structure to join. That is, the side frames 6L and 6R are branched from the rear end of the main frame 3 to the left and right. At that time, a reinforcing member 11 that is curved along the side surface of the rear end portion of the main frame 3 and the upper surfaces of the upper portions 6La and 6Ra of the side frames 6L and 6R is joined. The strength and rigidity of the connecting portion with the frames 6L and 6R are ensured. A cross pipe 7 is installed between the lower ends of the side frames 6L and 6R.
A pivot plate 10 is provided on the side frames 6L, 6R, and a rear fork 106 that can swing in the vertical direction is supported by the pivot plate 10.
Further, since the upper portions 6La and 6Ra of the side frames 6L and 6R extend at an angle that is horizontal or nearly horizontal, the upper space can be used effectively. In the present embodiment, as shown in FIG. 5, a battery 117 is disposed in the upper space of the upper portion 6La of the side frame 6L on the left side of the main frame 3.

  The main frame 3 is coupled with left and right seat rails 8L and 8R extending rearward. The left and right stays 9L and 9R are coupled to the side frames 6L and 6R, and the stays 9L and 9R extend rearward and obliquely upward to be coupled to the rear ends of the seat rails 8L and 8R, respectively.

4 and 5 show a state where the engine unit 101 is mounted on the body frame 1.
A bracket 12 is provided at the lower end of the down frame 4, and the bracket 12 supports the front portion of the crankcase 101 </ b> A of the engine unit 101. Further, a pair of left and right engine hangers 13 are provided on the cross pipe 7, and these engine hangers 13 support the rear part of the crankcase 101 </ b> A of the engine unit 101. In the present embodiment, the frame member around the lower portion of the engine unit 101 is omitted, and the engine unit 101 itself is used as a strength member.

  An engine hanger 14 extends downward from the main frame 3, and the engine hanger 14 supports the cylinder head 101 </ b> C of the engine unit 101.

A bracket 15 is joined to the upper portions 6La and 6Ra of the side frames 6L and 6R and the rear end portion of the main frame 3. The bracket 15 includes left and right suspension portions 16L and 16R that are suspended from the lower surfaces of the upper portions 6La and 6Ra of the side frames 6L and 6R toward the front and lower sides, and between the upper edges of the left and right suspension portions 16L and 16R. And a plate-like connecting member 17 for connecting the two. That is, the bracket 15 has an integral shape in which suspension portions 16L and 16R are suspended as suspension members on the left and right sides of the connecting member 17, and has a substantially U-shape or U shape that opens downward in a front view. The ends of the suspension portions 16L and 16R are connected to the crankcase 101A of the engine unit 101 to support the engine unit 101. In addition, the intensity | strength and rigidity as a bracket can be improved by shape | molding the rib 18 along the edge part of the connection member 17 and the suspension parts 16L and 16R of the both ends.
The upper edge surfaces of the connecting member 17 and the suspension portions 16L, 16R have shape portions along the rear portions of the upper portions 6La, 6Ra and the main frame 3, and are formed at the rear portions of the upper portions 6La, 6Ra and the main frame 3. Welding is performed (see welded spot 19 in FIG. 3).

  As described above, since the bracket 15 is joined to the joint where the left and right side frames 6L and 6R branch from the main frame 3, the bracket 15 also serves as a reinforcing member. Thereby, the strength and rigidity of the joint portion can be ensured while avoiding an increase in the number of parts and an increase in weld length.

  In addition, since the bracket 15 has an integrated shape in which the suspension portions 16L and 16R are suspended from the left and right of the connecting member 17, the bracket 15 is hardly affected by welding distortion, and the relative position accuracy of the suspension portions 16L and 16R is improved. Can be kept high.

  As mentioned above, although this invention was demonstrated with various embodiment, this invention is not limited only to these embodiment, A change etc. are possible within the scope of the present invention.

  1: Body frame, 2: Steering head pipe, 3: Main frame, 4: Down frame, 6L, 6R: Side frame, 6La, 6Ra: Upper part, 15: Bracket, 16L, 16R: Suspension part, 17: Connecting member , 100: motorcycle, 101: engine unit

Claims (3)

A main frame extending backward from the head pipe;
A motorcycle body frame including left and right side frames coupled to a rear end portion of the main frame,
Each of the side frames has a structure in which an upper portion thereof is curved inward in the vehicle width direction and is abutted against and joined to a side surface of a rear end portion of the main frame,
A body frame for a motorcycle, wherein a suspension member for supporting the engine unit is provided on an upper portion of each side frame.   The body frame of the motorcycle according to claim 1, wherein the left and right suspension members have an integrated shape in which the upper edges are connected by a connecting member.   3. The automatic according to claim 2, wherein the left and right suspension members and the connecting member that are integrally formed are welded to upper portions of the left and right side frames and a rear end portion of the main frame. Body frame for motorcycles.

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