JPH0672795U - Rear fork for motorcycle - Google Patents

Abstract

(57) [Abstract] [Purpose] Processing and assembly of the cross pipe 6 in the motorcycle rear fork 1 in which the left and right swing arms 2L and 2R extend at different angles P and Q with respect to the vehicle body center line 5. To facilitate. [Structure] The left and right swing arms 2L and 2R are connected by a cross pipe 6 that intersects perpendicularly with a line 8 that bisects the angle (P + Q) between these swing arms.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rear fork of a motorcycle.

[0002]

[Prior art]

 The rear wheel of a motorcycle is mounted on a vehicle body via a rear fork so that the rear wheel can swing up and down. Normally, this rear fork is provided at the front end as disclosed in, for example, Japanese Utility Model Laid-Open No. 58-70987. The left and right swing arms (hawk pipes) that have a pivotal support for the vehicle body are connected by a cross pipe (connection pipe).

By the way, the plane shape of the rear fork is not always symmetrical, and is often asymmetrical, for example, the rear fork 01 shown in FIG. In the figure, 2L and 2R are left and right swing arms, respectively. Swing arms 2L and 2R are provided with pivot bearings 3L and 3R respectively at the front ends thereof, and the rear fork 01 is pivotally supported on the body frame through the pivot bearings 3L and 3R. To be done. The pivot axis 4 connecting the pivot bearings 3L and 3R is orthogonal to the vehicle body center line 5, and the front ends of the swing arms 2L and 2R are equidistant from the vehicle body center line 5.

On the other hand, the rear ends of the swing arms 2L and 2R are not equidistant from the vehicle body centerline 5, and the distance y from the swingarm 2L to the vehicle body centerline 5 is from the swing arm 2R to the vehicle body centerline. It is larger than the distance x up to 5. This is due to the following reasons. A rear wheel RW is disposed on the vehicle body center line 5 between the rear end of the swing arm 2L and the rear end of the swing arm 2R. For example, in the chain-driven rear wheel, one side of the rear wheel RW is located. Since the sprocket wheel SW is overhanging on this side, the swing arm 2L on the sprocket wheel SW side must be overhanging to maintain an appropriate clearance with it.

As a result, the angle P formed by the swing arm 2L with respect to the vehicle body center line 5 at the front portion is larger than the angle Q formed by the swing arm 2R with respect to the vehicle body center line 5. That is, the left and right swing arms 2L and 2R extend at different angles with respect to the vehicle body center line 5.

In such a front portion, the left and right swing arms 2L and 2R are connected by a cross pipe 06, and the joint portion between the cross pipe 06 and the swing arms 2L and 2R is connected to a gusset plate 07a, 07b, 07c, It is reinforced by 07d. Conventionally, the cross pipe 06 has been arranged at a right angle to the vehicle center line 5.

[0007]

[Problems to be solved]

 Therefore, both ends of the cross pipe 06 must be cut at different angles according to the angles of the swing arms 2L and 2R, and the gusset plates 07a to 07d also have different shapes. Therefore, many types of processing dies are required, the number of types of parts is increased, and there is a possibility of misassembly in some cases, which is one of the causes of an increase in production cost and a decrease in productivity. It was

[0008]

[Means and Actions for Solving the Problems]

 The present invention has been made in view of the above circumstances. In the present invention, the left and right swing arms of the motorcycle rear fork extend at different angles with respect to the vehicle body center line. The left and right swing arms are connected by a cross pipe that perpendicularly intersects a line that bisects the angle between these swing arms.

According to the present invention, since the cross pipe intersects the left and right swing arms at the same angle, both ends of the cross pipe may be cut at the same angle, and therefore the same cutting die should be used for cutting both ends. In addition, there is no risk of erroneous processing, and since the cross pipe is symmetrical, erroneous assembly can be prevented.

Further, since the reinforcing gusset plates having the same shape can be used on the left side and the right side, the number of types of manufacturing molds can be small, and the possibility of misassembly is reduced.

[0011]

【Example】

 FIG. 2 is a plan view of the rear fork 1 according to the embodiment of the present invention. This rear fork 1 has the same structure as the above-mentioned rear fork 01 of FIG. 1 except for the cross pipe 6 and the gusset plates 7a to 7d, and therefore the same parts are designated by the same reference numerals. Detailed description is omitted.

In FIG. 2, reference numeral 8 is a line that bisects the angle (P + Q) formed by the swing arm 2L and the swing arm 2R at the front portion. Since the angle P is larger than the angle Q as described above, the bisector 8 is inclined to the swing arm 2L side with respect to the vehicle body center line 5.

The cross pipe 6 is arranged at a right angle to the bisector 8. Therefore, the cross pipe 6 intersects the swing arm 2L and the swing arm 2R at the same angle A (B). In other words, the end surface 6L of the cross pipe 6 on the swing arm 2L side and the end surface 6R of the swing arm 2R side are inclined at the same angle with respect to the center line 9 of the cross pipe 6. Therefore, when manufacturing the cross pipe 6, both ends may be cut at the same angle, so that the same cutting die can be used for cutting both ends, the required number of dies is reduced, and the risk of erroneous processing is eliminated. Further, since the cross pipe 6 is bilaterally symmetric and either end face may be applied to which swing arm, there is no risk of misassembly.

Further, in the gusset plate 7a and the gusset plate 7b, the side along the cross pipe 6 and the side along the swing arm 2L or the swing arm 2R form the same angle A 1. That is, if the gusset plate 7a is inverted, it will have the same shape as the gusset plate 7b, so it is sufficient to use the same material for the gusset plates 7a and 7b. The same applies to the gusset plates 7c and 7d.

Therefore, also for these gusset plates, the number of molds required to manufacture them is small, and the types of parts to be prepared are also small, so that productivity is improved and misassembly is prevented. Possibility is also reduced.

In the present embodiment, the space between the cross pipe 6 and the swing arms 2L, 2R is reinforced by a gusset plate which is separate from them, but gusset plate-like reinforcing pipe expansion portions are provided at both ends of the cross pipe 6. Even when they are machined together, the expanded parts at both ends have the same shape, so these expanded parts can be processed with the same machining die, and the possibility of erroneous machining and misassembly is reduced.

As described above, the distances x and y from the vehicle body center line 5 to the left and right swing arms 2L and 2R at the rear end portion are different, and as a result, the swing arms 2L and 2R are different from each other with respect to the vehicle body center line 5. Although the present invention has been described with respect to the rear fork 1 extending at different angles, even if the rear fork has the same x and y at the rear end, the left and right swing arms that are parallel to each other at the rear end are provided at the front. When the position where the bending starts toward the vehicle body centerline is displaced forward and backward, the left and right swing arms extend at different angles with respect to the vehicle body centerline as in the present embodiment. The present invention can be effectively applied to such a rear fork.

[0018]

[Effect of device]

 According to the present invention, it is easy to manufacture and process a cross pipe in a motorcycle fork rear fork, in which the left and right swing arms extend at different angles with respect to the vehicle body centerline, and to assemble the rear pipe to the rear fork. Fork productivity is improved.

[Brief description of drawings]

FIG. 1 is a plan view of a conventional rear fork.

FIG. 2 is a plan view of a rear fork according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Rear fork, 2 ... Swing arm, 3 ... Pivot bearing, 4 ... Pivot axis line, 5 ... Body center line, 6 ... Cross pipe, 7 ... Gusset plate, 8 ... Bisecting line, 9 ... Center line.

Claims (1)

[Scope of utility model registration request] 1. In a rear fork for a motorcycle, wherein left and right swing arms extend at different angles with respect to a center line of a vehicle body, a line that divides the left and right swing arms into two equal parts. A rear fork for a motorcycle, which is characterized by being connected by a cross pipe that vertically intersects with.