JPH10100979A - Steering system for motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with the use of split clamp structure to a handle crown by fixing upper cylindrical bodies of a front fork to the handle crown through steering handles. SOLUTION: Upper cylindrical bodies 5 of a front fork are fittingly inserted in round holes of a handle crown 7, and steering handles 19 are fitted to the upper ends of the upper cylindrical bodies 5. At this time, the upper cylindrical bodies 5 are fitted to round holes 24a of split clamp structure part 24, and in this state, tightening bolts are fastened to tighten the upper cylindrical bodies 5 by the split clamp structure bodies 24. Flanges 25 of the steering handles 19 are then fixed to the handle crown 7 by fixing bolts 27. Since the steering handles 19 are fixed to the handle crown 7, the upper cylindrical bodies 5 of the front fork are connected to the handle crown 7 through the steering handles 19 and fixing bolts 27. The split clamp structure parts are thereby used only for the steering handles, and its use to the handle crown can be dispensed with.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steering apparatus for a motorcycle, in which a steering handle and an upper cylinder of a front fork are connected to a steering shaft via a handle crown.

[0002]

2. Description of the Related Art Conventionally, when a so-called separate handle formed separately on the left and right is used as a steering handle of a motorcycle, a pair of left and right upper cylinders of a front fork is fixed to a handle crown fixed to a steering shaft. And
The left and right steering handles are fixed to these upper cylinders. The handle crown and the steering handle are formed into a desired shape by an aluminum die-casting method using an aluminum alloy as a material for weight reduction.

[0003] A portion for fixing the upper cylinder to the handle crown is a state in which a binding portion having a C-shaped cross section comprising a round hole and a slit is provided in the handle crown, and the upper cylinder is fitted into the round hole. A structure is adopted in which the gap between the slits is narrowed by bolts. That is, the upper cylindrical body of the front fork is tightened by the handle crown. This structure is hereinafter referred to as a split tightening structure. The steering handle is also fixed to the upper cylinder by this split tightening structure.

Further, in order to adopt the split tightening structure in an aluminum die-cast handle crown or steering handle, these are heat-treated so as to increase toughness.

[0005]

However, if the split fastening structure is used for the handle crown and the steering handle, the heat treatment must be applied to all of them as described above, so that the manufacturing cost increases. Also, in order to adopt the split tightening structure, the round holes, slits, and screw holes of the fastening bolts must be formed by machining.
Since the cost increases as the number of split fastening structures increases, it is required to reduce the number of components employing this structure.

The present invention has been made to solve such a problem, and an object of the present invention is to reduce the number of components having a split tightening structure in a motorcycle steering apparatus and reduce costs.

[0007]

According to a first aspect of the present invention, there is provided a motorcycle steering apparatus in which a handle crown is formed of a plate material, and an upper cylindrical body of a front fork is fitted to the handle crown.
The steering handle is fixed to the upper cylindrical body by being tightened, and is fixed to the handle crown. According to the present invention, the upper cylinder of the front fork is fixed to the handle crown via the steering handle. For this reason,
It is not necessary to adopt a split fastening structure for the handle crown.

[0008] A motorcycle steering apparatus according to a second aspect of the present invention is the motorcycle steering apparatus according to the first aspect.
The steering handle is disposed above the handle crown, and a spacer is interposed between them. According to the present invention, since the height of the steering wheel with respect to the steering wheel crown is changed by changing the thickness of the spacer, the steering wheel can be used in common for vehicles having different heights.

A motorcycle steering apparatus according to a third aspect of the present invention is the motorcycle steering apparatus according to the second aspect,
The spacer is formed of a synthetic resin. According to the present invention, it is possible to decorate the spacer exposed to the outside of the vehicle body by molding with a steering device.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of a motorcycle steering system according to the present invention will be described below in detail with reference to FIGS. FIG. 1 is a side view of a motorcycle employing a steering device according to the present invention, FIG. 2 is an enlarged side view of a main part,
FIG. 3 is a front view showing a state where the handle crown portion is viewed from the front of the vehicle body, FIG. 4 is a plan view of the handle crown portion,
5 is a plan view of the handle crown, FIG. 6 is a plan view of the spacer, and FIG. 7 is a perspective view of the left steering handle.

In these figures, reference numeral 1 denotes a motorcycle according to this embodiment, and reference numeral 2 denotes a front fork for supporting a front wheel 3 of the motorcycle 1. The front fork 2 is of a telescopic type in which an upper cylinder 5 is slidably inserted in a vertical direction into a lower cylinder 4 connecting the front wheels 3. The left and right upper cylinders 5 are connected to each other by a lower bracket 6 and a handle crown 7 described later, and a steering shaft 8 is formed.
(See FIG. 2).

The steering shaft 8 is rotatably supported on a head pipe 10 of a vehicle body frame 9 of the motorcycle 1, and a handle crown 7 is fixed to an upper end projecting upward from the head pipe 10 by a fixing bolt 11. I have. In FIG. 2, reference numeral 12 connected to the head pipe 10 denotes a tank rail of the vehicle body frame 9, and reference numeral 13 denotes a key switch with a handle lock. The key switch 13 is fixed to the handle crown 7 by a fixing bolt 13a.

In this embodiment, the handle crown 7 is formed of a steel plate into a shape shown in FIG. 5, and has a round hole 14 into which the steering shaft 8 is fitted and a round hole into which the upper cylindrical body 5 of the front fork 2 is fitted. 15 and a round hole 16 into which the upper part of the key switch 13 is fitted are formed by press working. The handle crown 7 has a screw hole 17 into which a bolt for fixing a steering handle described later to the handle crown 7 is screwed, and a key switch 1.
A screw hole 18 into which a bolt for fixing the handle 3 to the handle crown 7 is screwed is provided.

An upper end of the upper cylinder 5 of the front fork 2 is fitted with a round hole 15 of the handle crown 7 from below, and a steering handle 19 is fixed to an upper end thereof. To be supported by the handle crown 7. The steering handle 19 is of a so-called separate type and is attached to the upper cylinder 5 on the left side of the vehicle body and the upper cylinder 5 on the right side of the vehicle body. FIG. 7 shows the steering handle 19 provided on the left side of the vehicle body. The steering handle 19 disposed on the right side of the vehicle body has a structure which is symmetrical to that shown in FIG.

The steering handle 19 is connected to the upper cylindrical body 5.
And a handlebar 21 made of steel pipe fixed to the bracket 20. As shown in FIG. 2, an operation lever 22 of a clutch or a front wheel brake, a handle grip 23, and various switches (not shown) are attached to the handle bar 21, as shown in FIG.

The bracket 20 is formed by forging and subjected to a heat treatment so as to increase toughness. A split tightening structure 24 for binding the upper cylinder 5 and a fixing flange 25 are provided.
And are provided integrally. The split tightening structure 24 forms a round hole 24a into which the upper cylindrical body 5 is fitted, and a slit 24b connected to the round hole 24a, and a binding bolt 26 (FIG. 2).
4 to FIG. 4), the gap between the slits 24b is narrowed.

As shown in FIGS. 2 to 4, the fixing flange 25 is disposed on the center of the vehicle body in the left-right direction with respect to the split fastening structure 24, and is attached to the handle crown 7 with two fixing bolts 27. It has a fixed structure. In this embodiment, the steering handle 19 is disposed above the handle crown 7, and a spacer 28 is interposed between the lower surface of the fixing flange 25 and the upper surface of the handle crown 7.

The spacer 28 is formed by molding a material having good moldability, such as an aluminum alloy or a synthetic resin, into a shape shown in FIG. 6 by using a mold (not shown) so as to cover the handle crown 7 from above. I have. In this embodiment, the spacer 28 is formed of a synthetic resin. In addition, on the upper surface of the spacer 28, the decorative recess 2 is provided.
8a and 28b are formed. These recesses 28a, 2
Reference numeral 8b denotes a transcribed projection of a mold for molding the spacer 28. 6, reference numeral 29 denotes a round hole through which the upper cylindrical body 5 of the front fork 2 penetrates, and reference numeral 30 denotes a through hole through which a fixing bolt 27 for fixing the steering handle 19 to the handle crown 7 passes.

In order to assemble the steering apparatus thus constructed, first, the upper cylinder 5 of the front fork 2 is inserted into the round hole 15 of the handle crown 7, and the steering handle 19 is attached to the upper end of the upper cylinder 5. Install. When attaching the steering handle 19 to the upper cylinder 5, the split tightening structure 24
The upper cylindrical body 5 is fitted into the round hole 24a of the above, the tightening bolt 26 is tightened in this state, and the upper cylindrical body 5 is tightened by the split fastening structure 24.

Next, the flange 25 of the steering handle 19 is fixed to the handle crown 7 with fixing bolts 27. At this time, a spacer 28 is interposed between the steering handle 19 and the handle crown 7. By fixing the steering handle 19 to the handle crown 7 in this manner, the upper cylindrical body 5 of the front fork 2 is moved to the steering handle 1.
9 and to the handle crown 7 via fixing bolts 27.

Therefore, the upper cylinder 5 of the front fork 2 can be supported on the handle crown 7 without using the split fastening structure, so that only the steering handle 19 adopts the split fastening structure. In addition, the number of split fastening structures is reduced as compared with a conventional steering device that employs split fastening structures for both of them.

Further, in the steering apparatus shown in this embodiment, the steering handle 19 is disposed above the handle crown 7 and the spacer 28 is interposed between them, so that the thickness of the spacer 28 can be changed. As a result, the height of the steering handle 19 with respect to the handle crown 7 changes, so that the steering handle 19 can be used in common for vehicles having different heights. That is, by forming the spacer 28 for each vehicle model having a different height, one type of steering handle 19 can be used in each vehicle model without any machining.

Further, since the spacer 28 is formed of a synthetic resin, decoration (decoration recesses 28a, 28b) can be applied to the spacer 28 by molding. For this reason, as described above, since the spacer 28 used for sharing the steering handle 19 can be used as a decorative component, the steering device does not need to be provided with a component exclusively used for decoration. In this embodiment,
Since the upper surface of the handle crown 7 is covered with the spacer 28, even if the handle crown 7 is formed of a steel plate and the upper surface is formed as a rough surface, the handle crown 7 can be covered and hidden by the spacer 28.

It should be noted that the handle crown 7 can be formed by an aluminum die-casting method in addition to a steel plate. As shown in this embodiment, when the handle crown 7 is formed of a steel plate, it can be thinner than when it is formed by an aluminum die-casting method, so that a small-sized steering device can be obtained.

[0025]

As described above, according to the first aspect of the present invention, the upper cylinder of the front fork is fixed to the handle crown via the steering handle, so that the handle crown does not need to adopt the split fastening structure. Good. Accordingly, it is not necessary to perform heat treatment on the handle crown, and the number of machining steps performed on the handle crown can be reduced, so that the cost can be reduced.

According to the second aspect of the present invention, the height of the steering wheel relative to the steering wheel crown changes by changing the thickness of the spacer interposed between the steering wheel crown and the steering wheel. The steering wheel can be commonly used in other motorcycles. Therefore, the steering handle, which is relatively expensive due to the adoption of the split fastening structure, can be shared, and the cost can be further reduced.

According to the third aspect of the present invention, since the steering wheel is used to make the steering wheel common, and the spacer exposed to the outside of the vehicle body by the steering device can be decorated by molding, it is exclusively used. There is no need to provide components used for decoration. From this point, the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a side view of a motorcycle employing a steering device according to the present invention.

FIG. 2 is an enlarged side view showing a main part.

FIG. 3 is a front view showing a state in which a handle crown portion is viewed from the front of the vehicle body.

FIG. 4 is a plan view of a handle crown portion.

FIG. 5 is a plan view of a handle crown.

FIG. 6 is a plan view of a spacer.

FIG. 7 is a perspective view of a left steering handle.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motorcycle, 2 ... Front fork, 5 ... Upper cylinder, 7 ... Handle crown, 8 ... Steering shaft, 19
... Steering handle, 24 ... Split structure, 28 ... Spacer.

Claims (3)

[Claims] 1. A motorcycle steering system comprising a steering shaft fixed to a steering shaft and an upper cylindrical body of a front fork and a steering handle connected to the steering wheel crown, wherein the steering wheel crown is formed of a plate material. A steering device for a motorcycle, wherein the upper tubular body is fitted to the upper tubular body, and the steering handle is fixed to the upper tubular body by being fixed thereto and fixed to the handle crown. 2. The steering system for a motorcycle according to claim 1, wherein a steering wheel is disposed above the handle crown and a spacer is interposed between the steering wheel and the steering wheel. 3. The steering apparatus for a motorcycle according to claim 2, wherein the spacer is formed of a synthetic resin.