JPH111192A - Body frame of motorcycle - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To simplify the assembly of a body frame. SOLUTION: Left and right main frames 6 are put into a mold, and a cross member 7 for connecting these main frames is cast. The surroundings of each intermediate portion of the left and right main frames are cast in the swivel portion 8. Also, stays 10, 11 and 12 are integrally formed with the cast-in portion 8,
Further, the stay 13 is also formed integrally with the cross member 7.
The cast-in portion 8 and the main frame 6 are connected and reinforced by a connection reinforcing portion 9 so as to restrict the movement in the axial direction. At the time of the product, it comes into close contact with the mold surface to prevent air from entering.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle body frame of a motorcycle, and more particularly to a vehicle body frame having a pair of right and left main frames and a cross member connecting the main frames. .

[0002]

2. Description of the Related Art Japanese Unexamined Utility Model Publication No. 5-84592 discloses a pair of left and right main frames extending rearward from a head pipe, a pair of left and right pivot frames extending vertically from respective rear ends thereof, and a pair of left and right main frames. A body frame of a motorcycle including a cross member to be connected and various stays, and assembled by welding at respective connection ends is shown.

Japanese Patent Application Laid-Open No. 1-212679 discloses a vehicle body frame in which a head pipe is cast integrally with a frame pipe by casting a front end portion of the frame pipe.

[0004]

When assembling a vehicle body frame by welding, it is necessary to set and temporarily attach components in advance using a welding jig or the like, and there are many finishing operations after welding. The cost is high because it takes time and effort.

Further, in the case of a structure that requires welding on the back side, it is difficult to automate by a robot, so that handwork welding must be increased, and at this time, it is necessary to improve a part of the appearance. Requires a high level of skill in welding work. In addition, work and design are required in consideration of the reduction in material strength due to the thermal influence of welding and the reduction in dimensional accuracy due to thermal strain.

If the front end of the frame pipe is cast with a head pipe as disclosed in Japanese Patent Laid-Open No. 1-212679, at least welding work between the head pipe and the front end of the frame pipe can be omitted. In order to ensure rigidity, a cross member that connects the left and right main frame intermediate parts is essential. Since this cross member is formed separately from the frame pipe and then connected by welding, various problems associated with the above welding Can not solve.

[0007]

Means for Solving the Problems In order to solve the above problems, a first invention of the present application is a motorcycle having a pair of left and right main frames and a cross member connecting an intermediate portion between the left and right main frames. In the above body frame, the cross member may be a cast product in which the outer peripheries of the middle portions of the pair of left and right main frames are integrally cast at both ends in the length direction.

According to a second aspect of the present invention, in the first aspect, a through-hole is formed in a cast-in portion of the main frame and the cross member, and the through-hole is used to reinforce the connection with a caulking member. And

Further, a third invention is characterized in that, in the first invention, the main frame has a taper in a direction in which the mold for casting is removed.

[0010]

According to the first aspect of the invention, the left and right main frames and the cross member are integrated with each other by casting the cross member and casting the outer periphery of the middle portion of the main frame at both ends. Can be firmly connected.

This eliminates the necessity of welding after attaching the separate main frame and cross member to the jig, thereby reducing the number of man-hours, shortening the work time, reducing the cost, and increasing the degree of skill. Is not required, and the thermal effect on the strength does not need to be considered so much, so that the design becomes easy.

According to the second aspect of the present invention, since the side surface of the main frame is tapered, the inner surface of the mold is made to correspond to the tapered surface at the time of casting, so that the main frame and the mold come into close contact with each other by taper alignment. Burrs are less likely to occur during casting, and as a result, the appearance after casting is improved, and finishing work such as deburring is reduced, thereby improving workability.

According to the third aspect of the present invention, a through-hole is formed in the main frame and the cross member in the cast-in portion, and a connection reinforcing portion in which the main frame and the cast-in portion are crimped by a caulking member is provided by using this. Therefore, the connection with the cross member in the axial direction of the main frame can be strengthened.

[0014]

1 is an exploded perspective view of a body frame of a motorcycle according to the present invention, FIG. 2 is a side view of a cast-in portion, FIG. 3 is a plan view of a left side of the body, FIG. 4 is a sectional view taken along line 4-4 in FIG. 3, FIG. 5 is a sectional view showing a mold structure at the time of casting, and FIG.

First, the overall structure of the body frame of the motorcycle will be outlined with reference to FIG. The vehicle body frame includes a front portion 1 having a substantially V shape in plan view, a main portion 2 having a substantially H shape in plan view, and a pair of left and right pivot frames 3 attached to a rear end of the main portion 2.

The front part 1 has a head pipe 4 at its tip.
And a square pipe-shaped arm portion 5 extending rearward while expanding left and right, and is cast from a light alloy material such as an aluminum alloy.

Incidentally, the front part 1 is independent of the cast product.
The head pipe 4 and the arm portion 5 may be formed separately and assembled by welding or the like.

The main section 2 is integrated with a pair of left and right main frames 6 extending substantially linearly in the front-rear direction and a cross member 7 connecting the intermediate sections thereof. The portion is a cast-in portion 8 that is continuously integrated with the cross member 7.

The main frame 6 is provided on the upper surface of the cast-in portion 8.
And a stay 10, 11 extending vertically to support a fuel tank (not shown) and a stay 1 extending substantially horizontally to the inside of the vehicle body.
2 are integrally formed, and a stay 13 for an engine hanger is integrally formed below the cross member 7 so as to protrude downward.

The main frame 6 is extruded using a light alloy material such as an aluminum alloy, and has a rib wall 14 formed integrally and continuously in the longitudinal direction so that the cross-section has a substantially oval shape. Have been.

The side surface of the main frame 6 is formed as a ridgeline 15 at an intermediate portion in the vertical direction, and has tapered surfaces 16 and 17 which gradually taper upward and downward from the ridgeline 15, respectively.

The front ends of the left and right main frames 6 are fitted to the respective ends of the left and right arms 5, and the front part 1 and the main part 2 are joined by welding at these fitting parts.

The pivot frame 3 is a casting formed by using a light alloy material such as an aluminum alloy to be elongated in the vertical direction. The pivot frame 3 has a symmetrical shape, and has a connecting projection 18 protruding forward at the front edge side. Here, the main part 2 and the pivot frame 3 are integrated by fitting with the rear ends of the left and right main frames 6 and welding at the fitting parts.

A boss 19 is formed on the lower side surface of the pivot frame 3, and the front end of a rear arm constituting a rear wheel suspension device (not shown) is pivotably connected to the front end of the rear arm.

Next, the structure of the cross member 7 and the insert portion 8 will be described with reference to FIGS. As shown in these figures, the cross member 7 is cast into a shape that is lightened with a concave portion that opens downward using a light alloy material such as an aluminum alloy, and has a plurality of lateral ribs 20 extending in the left-right direction extending in the left-right direction. And vertical ribs 21.

The stay 13 extends downward continuously and integrally from the top 22 of the cross member 7 to form a part of a vertical rib.
Further, ribs 23 parallel to the horizontal ribs 20 are formed between the left and right sides of the stay 13 and the bottom of the cross member 7.

When the cross member 7 is cast, the cast-in portion 8 is formed by continuously casting the outer periphery of each of the intermediate portions of the left and right main frames 6 so as to be continuously and integrally formed with the left and right ends of the cross member 7. When each stay 10, 11, 1
2 is also integrally formed.

FIG. 5 shows a state in which a front portion or a rear portion of the main frame 6 with respect to the cast-in portion 8 is set between the upper die 30 and the lower die 31 during casting.
The mating surface 32 of the lower die 31 and the ridge line 1 of the main frame 6
5, the inner surfaces of the cavities 33 and 34 are tapered surfaces corresponding to the tapered surfaces 16 and 17 of the main frame 6.

The left and right main frames 6 have tapered surfaces 16 and 17 as side surfaces so that the widths in the left and right directions are maximum at the ridge 15 and narrower at both the upper and lower ends. It is formed on a slope having an angle θ, and as a result, has a tapered shape that gradually becomes narrower from the ridge line portion 15 in the die-cutting direction Z.

Therefore, when the main frame 6 is set in the cavities 33, 34, the tapered surfaces 16, 17
On the other hand, since the inner surfaces of the cavities 33 and 34 have corresponding tapered shapes, the tapered surfaces 16 and 17 can be air-tightly contacted with the mold surfaces of the cavities 33 and 34 by taper alignment.

Although not clearly shown in FIG. 5, caddies corresponding to the cross members 7 and the cast-in portions 8 of the upper mold 30 and the lower mold 31 are formed.

Therefore, by setting the left and right main frames 6 between the upper die 30 and the lower die 31 and injecting a molten light alloy material such as an aluminum alloy, the intermediate members of the cross member 7 and the left and right main frames 6 are formed. As a result, the main portion 2 in which the insert portion 8 and the stays 10, 11, 12, 13 are integrally formed is obtained.

After the casting, as shown in FIG. 6, the connection between the main frame 6 and the insert portion 8 is strengthened. That is, first, a through-hole 25 is drilled with respect to A in the drawing immediately after casting (B), and then a commercially available caulking nut 26 is attached to this hole (C).
By caulking, the insert portion 8 and the main frame 6 are firmly connected to each other, and a relative displacement of the insert portion 8 and the main frame 6 in the axial direction is prevented.

If necessary, another coupling strengthening part may be provided in place of the top coupling strengthening part 9 or in combination therewith, as shown by phantom lines in FIG. be able to.

When a very large bonding strength is not required, commercially available cashmere rivets can be used.

Next, the operation and effect of this embodiment will be described. First, the cross member 7 is formed by casting, and the left and right main frames 6 and the cross member 7 are formed by casting the outer periphery of the middle portion of the main frame 6 at both ends.
Can be integrated with each other.

As a result, it is not necessary to weld the main frame 6 and the cross member 7 separately after attaching them to the jig, so that the number of man-hours is reduced, the working time is shortened, the cost is reduced, and the cost is reduced. Skill is not required, and it is not necessary to consider much the thermal effect on the strength.

Further, since the side surfaces of the main frame 6 are tapered surfaces 16 and 17, the inner surfaces of the cavities 33 and 34 provided in the mold correspond to the tapered surfaces, so that the tapered surface 16 of the main frame 6 can be formed. , 17
However, since the molds are brought into close contact with the inner surfaces of the cavities 33 and 34 by taper alignment, casting burrs are less likely to occur during casting, and as a result, the appearance after casting is improved and finishing work such as deburring is reduced. Therefore, workability is improved.

In addition, a through-hole 25 is formed in the main frame 6 and the cross member 7 in the cast-in portion 8, and a caulking nut 26 serving as a caulking member is used by using this.
Since the main frame 6 is provided with the connection reinforcing portion 9 in which the cast-in portion 8 is caulked, the connection between the main frame 6 and the cross member 7 in the axial direction can be strengthened.

In addition, since the various stays 10, 11, 12 and 13 can be integrally formed when the cross member 7 and the cast-in portion 8 are cast, there is no need to separately form and then weld them. .

Further, the cross member 7 has a lightweight and rigid structure by integrally forming the lightening concave portion, the horizontal rib 20 and the vertical rib 21 in a portion that is hardly seen, and the rib 23 is connected to the stay 13 by the cross member. The stay 13 is sufficiently formed by being integrally formed between the members 7.

The present invention is not limited to the above embodiment, but can be variously modified.
Can be formed as a pipe member such as iron, each stay can be formed as a separate pressed product, and the pivot frame 3 can be formed as a pressed product.

If the cross member 7 and the cast-in portion 8 are formed at the connecting portion between the front portion 1 and the main portion 2 or the connecting portion between the main portion 2 and the pivot frame 3, the front portion 1 and the main portion 2 are formed. In addition, welding between the pivot frames 3 can be omitted.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a body frame of a motorcycle according to the present invention.

FIG. 2 is a side view of an insert portion.

FIG. 3 is a plan view of the left side of the vehicle body.

FIG. 4 is a sectional view taken along line 4-4 in FIG. 3;

FIG. 5 is a sectional view showing a mold structure during casting.

FIG. 6 is a view showing a process of strengthening the connection of the cast-in portion

[Explanation of symbols]

6: Main frame, 7: Cross member, 8: Cast-in part, 9: Coupling reinforcement part, 10, 11, 12, 13: Stay

Claims (3)

[Claims] 1. A motorcycle body frame having a pair of left and right main frames and a cross member connecting an intermediate portion between the left and right main frames, wherein the cross members are provided at both ends in a longitudinal direction. A body frame for a motorcycle, characterized in that it is a casting in which the outer peripheries of an intermediate portion of a pair of main frames are integrally cast. 2. The automatic apparatus according to claim 1, wherein a through hole is formed in a cast-in portion of said main frame and said cross member, and said through hole is used to reinforce with a caulking member. Body frame of a motorcycle. 3. The motorcycle body frame according to claim 1, wherein said main frame has a taper in a direction in which a mold for casting is removed.