JPH0686231B2 - Body frame for motorcycles - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a casting frame for a motorcycle, and more particularly to a lightweight frame.

[Prior Art] A body frame of a motorcycle is known in which a head pipe, a main frame portion, and a rear swing arm support portion mounting portion are integrally cast from aluminum, and a tool is provided on a side of a carburetor of the main frame portion. There is also one having an insertion port formed therein (see, for example, JP-A-61-215187).

Such an opening is appropriately provided for the purpose of lightening the weight and reducing the weight, maintainability, and the like.

[Problems to be Solved by the Invention] By the way, the interest of the casting frame is to improve the balance between weight reduction and high rigidity.

Therefore, although it is possible to reduce the weight by forming the opening, it is necessary not to reduce the rigidity.

Further, it is conceivable to provide a large number of ribs for weight reduction and high rigidity, but this should not impair the appearance of the vehicle body.

Therefore, the present invention aims to reduce the weight by forming an opening, at the same time to achieve high rigidity without impairing the appearance,
In addition, it is a first object of the present invention to contribute to simplification of the structure, downsizing, and facilitation of the binding work by the binding portion. Further, a second object is to effectively use the opening as a place for forming a binding portion for connecting the left and right divided frames to each other at a mating surface and a tool insertion port for the binding portion.

[Means for Solving Problems] A frame of a motorcycle according to a first aspect of the present invention includes a main frame portion that extends obliquely downward and rearward in a front-rear direction of a vehicle body to support an engine and the like, and is divided into left and right parts. In a cast frame obtained by assembling a frame, the main frame portion has a substantially U-shaped cross section that opens downward, the upper wall surface is divided into left and right along a substantially center line of the vehicle body, and left and right along the dividing line. Standing wall-shaped mating parts are provided, and binding parts are respectively provided on the left and right mating parts. The left and right bonding parts connect the left and right divided frames to each other. And a rib for projecting inward is provided at the edge of the opening, and a portion for which strength is required is thickened. Characterized by being formed into To do.

The frame of the motorcycle according to the second aspect of the present invention is a cast frame obtained by assembling left and right split frames, and extends diagonally backward and downward in the front-rear direction of the vehicle body to support an engine and the like, and has a front end portion. In a main frame part provided with a head pipe, the vicinity of the head pipe of the main frame part is widened in a side view to form a duct for sucking air, and the duct projects inward at an opening edge portion of the duct. And a wall portion extending in the vehicle width direction from the edge portion of the duct that opens inward of the vehicle body toward the mating surface, and the left and right divided frames are joined to each other on the mating surface. It is characterized in that a binding portion for coupling is provided, and a tool for this binding portion can be put into and taken out of the duct from the side of the vehicle body.

[Operation of the Invention] In the first invention, an opening for lightening is formed in the side surface,
Since ribs formed by bending inward are provided at the edges, the ribs contribute to strengthening the overall rigidity. Therefore, even if the weight is reduced by forming the opening, the rigidity of the required strength is maintained.

Moreover, since it is a cast frame, only the portion requiring strength is formed thick, and as a result, the portion not requiring much strength can be largely removed.

In addition, the main frame portion has a substantially U-shaped cross section that opens downward, and the left and right side surface portions of the main frame portion are separated from each other and maintain a predetermined distance, so that the ribs provided at the edges of the opening portion can be projected inward. It is possible, and even if a large number of ribs are provided, the appearance is not impaired.

Furthermore, since binding portions are respectively provided on the standing wall-shaped mating portions formed on the left and right along the dividing line, and the left and right coupling frames are connected to each other by these binding portions, the standing wall-shaped reinforcing member By forming the binding part using the mating part, the structure can be simplified, and since the binding part is located in the vicinity of the dividing line, its size and weight can be reduced. Since it is formed on the upper wall surface of the main frame part, the binding work becomes easy.

Further, in the second invention, a wall portion extending in the vehicle width direction from an edge portion of the duct, which is one of the opening portions, which is opened inward of the vehicle body toward the mating surface, is provided. Since there is a binding part for joining the left and right split frames to each other on the mating surface, place the tool in a duct from the side of the vehicle body as a binding part at a place that is not conspicuous and does not damage the appearance of the body frame. Combine left and right split frames.

[Embodiment] FIGS. 1 to 8 show an embodiment of the present invention. In the motorcycle shown in FIG. 1, reference numeral 1 is a handlebar, 2 is a front fork, and 3 is a front wheel. This front fork 2
Is attached to the front end of the vehicle body frame 5 via the head pipe 4. P is a resin cover mounted above the vehicle body frame 5 and covering a fuel tank (not shown).

The body frame 5 is a diamond type frame,
The engine 6 is suspended and supported below it. A radiator 7 is attached to the front of the engine 6. A rear swing arm 8 is rotatably attached to a rear portion of the vehicle body frame 5, and a rear wheel 9 is supported at a rear end of the rear swing arm 8.

The vehicle body frame 5 is composed of left and right divided frames 10 and 11, and is formed by bolt connection so as to form a substantially U-shaped cross section that opens downward (see FIG. 4).

Each of the divided frames 10 and 11 is an integrally cast product by aluminum die casting and has an average wall thickness of 2.5 mm, which is the most advantageous in terms of correlation with moldability and strength.

The divided frames 10 and 11 are bilaterally symmetric, and the respective constituent parts are also formed symmetrically. Therefore, in the following description,
As a general rule, the divided frame 10 (left side) will be described. Therefore, in principle, the components of the right divided frame 11 are indicated by the same reference numerals as those of the left divided frame 10.

The vehicle body frame 5 includes a front portion A, a main frame portion B that supports the engine 6, a fuel tank, and the like, a rear swing arm support portion C that is bent behind the main frame portion B, and an extension portion that extends below the main frame portion B. It consists of D and. In addition, the upper surface of the main frame portion B is folded back in the horizontal direction to form an upper wall surface E.
Is doing.

Further, on the mating surface of the upper wall surface E, a mating portion F having a standing wall shape is formed in the front-rear direction.

The front portion A is provided with a head pipe mounting portion 12 which is curved in a semi-cylindrical shape to hold the head pipe 4. A coupling portion 13 having a large number of bosses for bolting is formed at the tip portion thereof. A duct 14 is formed slightly rearward of the head pipe mounting portion 12, and a coupling boss portion 15 for bolting is formed in the recess. duct
The reference numeral 14 takes in outside air while traveling and also serves as a heat exhaust port of the radiator 7 when the vehicle is stopped.

The extended portion D is formed by a truss member 16 protruding downward from the main frame portion B in a triangular shape, an opening 17 is formed inside thereof, and a bracket 16a provided in the front portion of the truss member 16 is formed. It also serves as the exhaust port of the radiator 7 attached to the engine and the maintenance port of the cylinder head portion 6a of the engine. An engine hanger 18 is formed at the lower end.

A step portion is formed in the longitudinal direction on the side surface of the main frame portion B, and characters and the like are stamped on the step portion.

On the rear side of the main frame portion B, an opening portion 19 which is an adjustment opening on the upper portion of a carburetor (not shown) is formed, and a mounting boss 20 and an engine hanger 21 are formed above and below the opening portion 19.

The rear swing arm support portion C is bent from the rear end portion of the main frame portion B and extends downward, and a pivot mounting hole 22 is formed in the center thereof, and an engine mounting hole 23 and a step holder are formed in the lower portion. Mounting holes 24a (not shown) and main stand mounting holes 25, 25b are formed. A cushion unit mounting portion 26 is formed on the upper portion. A boss portion 24b for mounting the other side of the step holder is formed below the cushion unit mounting portion 26.

Bosses 27 to 31 are formed on the upper wall surface E along the front-rear direction of the mating portion F, and bulging portions 32 to 34 for reinforcement are formed between adjacent bosses. Each boss 27 to 29
Are reinforced by ribs 35 to 39. Of these, rib
35 and 36 and 37 and 38 are formed so as to sandwich the bulging portions 32 and 33, respectively. A rib 40 is formed at the center of the bulging portion 34.

A substantially U-shaped notch 41 is formed between the bosses 29 and 30 of the upper wall surface E so as to form an engine adjusting port when the left and right divided frames 10 and 11 are combined. Further, a notch portion 42 for forming a cab adjusting opening is provided at a portion behind the notch portion 41 and separating the mounting bosses 30 and 31. The cushion unit mounting portion 26 is thickly formed at the rear end edge of the notch portion 42 for reinforcement, and the cushion unit mounting boss 43 and the coupling bosses 44 of the left and right divided frames 10 and 11 are provided here. Are formed.

Further, a large number of ribs are formed inside the side surface of the divided frame 10. Of these, the front portion A and the main frame portion B are formed with ribs 45 intersecting in a substantially rhombic shape, whereby the rib cross section is widened and a high strength structure similar to a honeycomb structure is formed.

The rear swing arm support portion C is mainly provided with ribs 46 formed radially around the pivot mounting hole 22 and partially provided with ribs 47 intersecting with the ribs 46. The density of these ribs is arranged in a coarse and dense manner according to the required strength, the rear swing arm support portion C portion having the pivot attachment hole 22 and the cushion unit attachment portion 26 is the densest, and the main frame portion B is the coarsest. Is configured. Further, a rib 48 which is continuous in a triangular shape also in the extended portion D part
Are formed.

The divided frames 10 and 11 are put together, and the boss portions 13, 15 and 27 to 31 are bolted. As a result, a strong vehicle body frame 5 having a substantially U-shaped cross section that opens downward is assembled.

At this time, on the upper wall surface E of the main frame portion B, the binding portions (each of the boss portions 27 to 31) are provided in the standing wall-shaped mating portions F formed on the left and right along the dividing line that is substantially the center of the vehicle body. Therefore, the joining portion (27
To 31), the structure can be simplified.

In addition, since the left and right binding portions (27 to 31) are located near the dividing line, the size and weight can be reduced, and the binding portions (27 to 31) are located on the upper wall surface F of the main frame portion B. Since it is formed, the binding work becomes easy.

Here, the mounting parts for the vehicle body frame 5 will be briefly described. First, seat rail 50 consists of main pipe 51 and reinforcement pipe 52.
And mounting ends 53 and 54 are provided on each. The mounting ends 53 and 54 are attached to the mounting boss 20 and the coupling boss 44.
It corresponds to.

The upper mounting end 56 of the cushion unit 55 that is vertically installed in the space formed at the front end of the rear swing arm 8 is
It is configured to be supported by the cushion unit mounting portion 26 by using the mounting boss 43, and the lower mounting end portion 57 is connected to the bottom surface of the rear swing arm 8 by a bell crank 58 and is connected to the bell crank 58. One end of the link 59 is fastened together with a main stand described later.

The main stand 60 has a pair of brackets 61 and 62,
Mounting holes 63a and 63b facing the main stand mounting holes 25a and 25b, and a stand mounting hole 63c are formed in each of them. In addition, a cross pipe 63 is provided between the brackets 61 and 62.
d and 63e are laid horizontally. One end of the link 59 is pivotally attached to the crossbar 63e. The upper end of the stand leg portion 64 is pivotally attached to the stand attachment hole 63c.

Next, the structure of each opening will be further described with reference to FIGS. Each of the openings in the present embodiment also serves as a lightening hole for reducing the weight, and a rib bent inward at a substantially right angle is formed at the peripheral edge of the opening. For example, as shown in FIGS. 5 to 7, ribs 14a, 17a and 19a are formed inward at the opening edge portions of the openings 14, 17 and 19 to increase rigidity. Therefore, the ribs 14a, 17a, and 19a allow the openings 14, 17 and 19 to be formed without lowering the rigidity. Moreover, since the main frame portion B has a substantially U-shaped cross section that opens downward, and the left and right side surface portions of the main frame portion B are spaced from each other and maintain a predetermined distance, these ribs can project inward from each other. Therefore, despite the large number of ribs thus provided, the appearance is not impaired.

In addition, as shown in FIGS. 4 and 7, the lower end of the main frame portion is also formed inward with the bent portions 10a, 1a.
1a and 16b are provided respectively, which contributes to increased rigidity. Further, the opening 41 formed in the upper wall surface E and
An upward bent portion is formed on the peripheral edge portion of 42 and acts in the same manner.

Also, as shown in FIG. 8, a duct that is an example of an opening.
The 14 is subjected to a kind of design treatment together with the coupling boss 15 which is a binding provided inside thereof. In addition, since the left and right side surfaces of the main frame portion B are spaced apart from each other, the coupling boss portion 15 is provided with a distance from the opening edge portion of the duct 14 located on the inner side of the vehicle body toward the vehicle body center, which is a mating surface. It is possible to provide a wall portion extending in the width direction, and by effectively utilizing this wall portion, the coupling boss portion 15 can be provided at a position deeper into the vehicle body center than the outer surface.
Therefore, even if the coupling boss portion 15 is provided, the appearance is not spoiled. Further, using the opening of the duct 14, the bolt 15a
A binding tool 15b such as a box wrench can be put in and out from the side of the vehicle body. Further, when the left and right divided frames 10 and 11 are joined to each other at the joining boss portion 15, they are located in the vicinity of the head pipe 4, which contributes to firmly holding them.

[Effects of the Invention] In the first invention, an opening for lightening is formed, and a rib formed by bending is provided at the edge thereof, and moreover, since it is a casting frame, only the portion requiring strength is provided. Since it can be formed to be thick, it is possible to reduce the thickness of the body frame as much as possible while maintaining the overall frame rigidity within a predetermined range, and it is possible to reduce the thickness of a portion that does not require much strength.

In addition, the main frame part has a substantially U-shaped cross section that opens downward, and the left and right side surface parts of the main frame part are separated from each other and maintain a predetermined interval, so that the ribs provided at the edge of the opening part should protrude inward. Therefore, even if a large number of ribs are provided, the appearance is not impaired and the appearance can be kept good.

Furthermore, since binding portions are respectively provided on the standing wall-shaped mating portions formed on the left and right along the dividing line, and the left and right coupling frames are connected to each other by these binding portions, the standing wall-shaped reinforcing member By forming the binding part using the mating part, the structure can be simplified, and since the binding part is located in the vicinity of the dividing line, its size and weight can be reduced. Since it is formed on the upper wall surface of the main frame part, the binding work becomes easy.

Further, in the second invention, a wall portion extending in the vehicle width direction from an edge portion of the duct, which is one of the opening portions, which is opened inward of the vehicle body toward the mating surface, is provided. Since the binding portion for connecting the left and right divided frames to each other at the mating surface is provided, a less conspicuous place can be used as the binding portion, and the appearance of the vehicle body frame can be maintained. Moreover, since the left and right split frames can be joined by inserting a tool into the duct from the side of the vehicle body, the binding work becomes easy. In addition, the head pipe part can be strengthened.

[Brief description of drawings]

1 to 8 show an embodiment, FIG. 1 is a side view of a vehicle body, FIG. 2 is an exploded perspective view, FIG. 3 is a side view, and FIG. 4 is a sectional view taken along line IV-IV of FIG. 5 is a sectional view taken along line VV of FIG.
FIG. 6 is a sectional view taken along line VI-VI in FIG. 3, and FIG. 7 is VII in FIG.
-VII sectional view, and FIG. 8 is a VIII-VIII sectional view of FIG. (Explanation of symbols) 5 ... Body frame, 10, 11 ... Divided frame, 14 ...
Duct (opening), 15 …… Boss part, 17, 19, 41, 42 ……
Openings, 14a, 17a, 19a …… ribs, 15a …… bolts, 15b
……tool.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A 61-67685 (JP, A) JP-A 62-26177 (JP, A) JP-A 60-176876 (JP, A) JP-A 61- 75083 (JP, A) JP 61-160375 (JP, A) JP 61-178276 (JP, A) Actually opened 61-3091 (JP, U) Actually opened 59-105703 (JP, U) Actual Development Sho 61-15630 (JP, U)

Claims (2)

[Claims] 1. A body frame for a motorcycle, which is a cast frame obtained by assembling left and right divided frames, the body frame for a motorcycle including a main frame portion that extends obliquely backward and downward in the front-rear direction of the vehicle body to support an engine and the like. The main frame portion has a substantially U-shaped cross section that opens downward, the upper wall surface is divided into left and right along a substantially vehicle center line, and vertical wall-shaped mating portions are provided along the dividing line. Each of the standing wall-shaped mating portions is provided with a binding portion, and the left and right binding portions connect the left and right divided frames to each other. The left and right side surface portions of the main frame portion are separated from each other to maintain a predetermined distance. In addition, an opening for lightening is formed on the side surface, a folded-back rib protruding inward is provided at the edge of the opening, and a portion requiring strength is formed thick. Characterized by The vehicle body frame for a motorcycle. 2. A cast frame obtained by assembling left and right split frames, the main frame portion extending obliquely rearward and downward in a front-rear direction of a vehicle body for supporting an engine and the like, and having a head pipe at a front end portion thereof. In the provided one, the vicinity of the head pipe of the main frame portion is widened in a side view to form an air intake duct, and a folded-back rib protruding inward is provided at an opening edge portion of the duct, and the duct is provided. A wall portion that extends in the vehicle width direction from the edge portion that opens to the inside of the vehicle body toward the mating surface, and a binding portion for connecting the left and right divided frames to each other at the mating surface is provided on the wall portion, A tool for this binding portion can be moved in and out of the duct from the side of the vehicle body.
Body frame for wheeled vehicles.