JP2003004491A - Gear unit waterproofing structure for meter cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the waterproofing property of the connection between a meter cable and a gear unit, while reducing cost. SOLUTION: The front end section of a rubber pipe 12 is extended to the base 21 of a cylindrical section 7 from a unit 11 for connecting the meter cable 5. The cylindrical body 22 of the gear unit 4 is bound tightly with the extended- side end section of the pipe 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waterproof structure for a gear unit for a meter cable, which seals a connecting portion between a gear unit for a meter cable mounted on an axle of a front wheel of a motorcycle and a rotary meter cable, for example. is there.

[0002]

2. Description of the Related Art Conventionally, in a motorcycle, a meter cable for transmitting wheel rotation to a speedometer transmits rotation of the front wheel via a gear unit mounted on the axle of the front wheel. A conventional meter cable gear unit will be described with reference to FIG. The figure (a) is a side view and the figure (b) is a rear view.

In FIG. 3, reference numeral 1 is a lower tube of a front fork, 2 is a front wheel axle, 3 is a front wheel hub, 4 is a meter cable gear unit, and 5 is a meter cable. The gear unit 4 is engaged with the lower tube 1 and the rotation of the housing 6 is restricted.
And a worm and a worm wheel (not shown) provided inside the housing 6.

The worm is arranged so as to be located on the same axis as the axle 2, and is connected to the hub 3 so as to rotate integrally therewith. The worm wheel is rotatably supported by a cylindrical portion 7 formed in the housing 6 so as to extend in the front-rear direction of the vehicle body and is meshed with the worm.

In the meter cable 5, an inner wire (not shown) is rotatably inserted into an outer tube 8, and a tip portion 9 of the inner wire is connected to a connector 10 of the worm wheel.
Connection nut 11 provided at the tip of the outer tube 8
Is screwed onto the cylindrical portion 7. By tightening the nut 11, the meter cable 5 is connected to the cylindrical portion 7 with the tip of the outer tube 8 in contact with the rear end of the cylindrical portion 7.

At the tip of the meter cable 5, the connecting portion between the outer tube 8 and the nut 11 is reinforced, and in order to prevent water from entering the cable and the gear unit 4 from the connecting portion, A rubber pipe 12 is attached. The pipe 12 has a rear end portion 12a formed to have a diameter smaller than that of the front end portion 12b so as to be in close contact with the outer tube 8, and the front end portion 12b is covered with the nut 11.

[0007]

However, even if the rubber pipe 12 is used as described above, it is not possible to prevent water from entering the gear unit 4.
This is a nut 1 for crowning the front end of the pipe 12.
In No. 1, the outer surface is knurled, and the water penetrates into the pipe 12 through the knurl groove 11a. To improve waterproofness, nut 1
It is conceivable to interpose an O-ring (not shown) on the inner side of 1 and at the connecting portion between the outer tube 8 and the cylindrical portion 7. However, if this configuration is adopted, the number of parts is increased by the amount of the O-ring, resulting in an increase in cost.

The present invention has been made to solve the above problems, and an object thereof is to improve the waterproof property of the connecting portion between the meter cable and the gear unit while reducing the cost.

[0009]

In order to achieve this object, a waterproof structure for a gear unit for a meter cable according to the present invention is made of rubber covering a connecting portion between a nut for connecting the meter cable and an outer tube of the meter cable. The tip end portion of the seal member is extended from the nut to the base side of the cylindrical portion of the gear unit, and the cylindrical portion is tightly bound at the extended side end portion of the seal member. According to this invention,
Since the tip end portion of the seal member is in close contact with the outer peripheral surface of the cylindrical portion over the entire area in the circumferential direction, the entire area between the cylindrical portion of the gear unit and the outer tube of the meter cable is covered and sealed by the seal member.

A waterproof structure for a gear unit for a meter cable according to a second aspect of the present invention is the waterproof structure for a gear unit for a meter cable according to the first aspect of the invention, wherein the cylindrical portion of the gear unit has a rear end. It is formed so as to be located rearward of the vehicle body from the maximum diameter portion of the lower tube of the front fork.

According to the present invention, as compared with the case where the rear end of the cylindrical portion is located right beside the maximum diameter portion of the lower tube of the front fork, the space for inserting the finger is relatively large when the nut is attached and detached. Get wider

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a waterproof structure for a gear unit for a meter cable according to the present invention will be described in detail below with reference to FIGS. 1 and 2. Here, a mode in which the gear unit is mounted on the front wheel of the motorcycle will be described. FIG. 1 is a side view showing a front portion of a motorcycle adopting a waterproof structure according to the present invention, FIG. 2 is a view showing a waterproof structure according to the present invention, FIG. 1 (a) is a side view, and FIG. Is a rear view. In these figures, the same or equivalent members as those described with reference to FIG. 3 are designated by the same reference numerals, and detailed description thereof will be appropriately omitted.

In FIG. 1, reference numeral 21 indicates a motorcycle according to this embodiment. Reference numeral 22 is a front wheel, 23 is a front fork, 24 is a steering wheel, 25 is a speedometer, 26 is an engine, and 27 is a leg shield. A gear unit 4 for a meter cable is mounted on the axle 2 of the front wheel 22 between the lower tube 1 on the left side of the vehicle body of the front fork 23 and the hub 3 of the front wheel 22.

In the meter cable gear unit 4 shown in FIGS. 2 (a) and 2 (b), a cylindrical portion 7 for mounting the meter cable 5 is formed on a housing 6 in a cylindrical base portion 31.
And the cylindrical body 3 press-fitted and fixed to the rear end of the base 31.
It is composed of 2 and. The base portion 31 is formed integrally with another portion of the housing 6. The housing 6 is formed of synthetic resin or casting, and the mounting seat (press-fitting hole) of the base 31 is formed by machining. In the connection portion between the base portion 31 and the cylindrical body 32, the press-fitted portion of the cylindrical body 32 is in close contact with the inner peripheral surface of the base portion 31 over the entire area in the circumferential direction so that water does not enter inside.

The cylindrical body 32 is made of synthetic resin or brass, and the nut 1 of the meter cable 5 is provided at the rear end thereof.
A female screw for screwing 1 is formed. The reason why the cylindrical portion 7 is composed of the base portion 31 and the cylindrical body 32 is that the structure of the mold is complicated and the cost is increased in order to mold the long cylindrical portion 7 by casting. is there.
The length of the cylindrical portion 7 including the base portion 31 and the cylindrical body 32 is
As shown in FIG. 2A, the rear end of the cylindrical body 32 is set to be located rearward of the vehicle body with respect to the maximum diameter portion of the lower tube 1 of the front fork 23. In addition, the cylindrical body 3
The outer diameter of 2 is set to be equal to the maximum diameter of the nut 11.

The rubber pipe 12 attached to the tip of the meter cable 5 has a tip 12b (a large diameter portion on the front side).
Is longer than before. More specifically, in this pipe 12, the front end 12b is fixed to the outer tube 8 of the meter cable 5 with the rear end 12a fixed to the nut 1.
It is formed to have a length extending from 1 to the front side (the side of the base portion 31). The outer tube 8 is shown in FIG.
As shown in FIG.
A pipe 8b made of metal is fixed to a, and the pipe 8b made of metal is fastened to the cylindrical body 32 by a nut 11. The rear end portion 12a (small diameter portion) of the rubber pipe 12 is in close contact with the outer peripheral surface of the flexible portion 8a to prevent water from entering from the rear side.

The tip portion 12b of the pipe 12 is formed so that the inner diameter is slightly smaller than the outer diameter of the cylindrical body 32, and is covered with the cylindrical body 32 while being elastically deformed and expanded in diameter. That is, the tip portion 12b of the pipe 12 is
The inner peripheral surface is in close contact with the outer peripheral surface of the cylindrical body 32 to bind the cylindrical body 32 tightly and prevent water from entering from the front side. This rubber pipe 12 constitutes the sealing member according to the present invention.

According to the waterproof structure in which the rubber pipe 12 is thus formed, the tip portion 12b of the rubber pipe 12 is formed.
From the connecting nut 11 of the meter cable 5 to the cylindrical portion 7
Since the cylindrical body 32 is tightly bound by the extending side end of the pipe 12, the tip end 12b of the pipe 12 adheres to the outer peripheral surface of the cylindrical body 32 over the entire area in the circumferential direction. However, water can be prevented from entering.

In this embodiment, the cylindrical portion 7 of the gear unit 4 is formed so that its rear end is located rearward of the vehicle body with respect to the maximum diameter portion of the lower tube 1 of the front fork. Compared with the case where the nut 11 is located right beside the maximum diameter portion, the space for inserting the finger when the nut 11 is attached and detached becomes relatively large. Therefore, the meter cable 5 can be easily attached and detached.

[0020]

As described above, according to the present invention, the entire area between the cylindrical portion of the gear unit and the outer tube of the meter cable is covered and sealed by the seal member, so that the seal structure is different from the conventional seal structure. Therefore, the number of parts does not increase, and the waterproofness of the connecting portion between the meter cable and the gear unit can be improved while reducing the cost.

According to the second aspect of the invention, as compared with the case where the rear end of the cylindrical portion is located right next to the maximum diameter portion of the lower tube of the front fork, there is a space for inserting the finger when the nut is attached and detached. Since it is relatively wide, the meter cable can be easily attached and detached.

[Brief description of drawings]

FIG. 1 is a side view showing a front portion of a motorcycle which adopts a waterproof structure according to the present invention.

FIG. 2 is a diagram showing a waterproof structure according to the present invention.

FIG. 3 is a diagram showing a conventional gear unit for a meter cable.

[Explanation of symbols]

5 ... Meter cable, 4 ... Gear unit, 7 ... Cylindrical part, 8 ... Outer tube, 11 ... Nut, 12 ... Pipe, 12b ... Tip part, 31 ... Base part, 32 ... Cylindrical body.

Claims (2)

[Claims] 1. A nut for connecting a rotary meter cable is screwed onto the cylindrical portion of the gear unit for meter cable,
In a waterproof structure of a meter cable gear unit in which a connecting portion between the nut and the outer tube of the meter cable is covered with a tubular seal member, a tip end portion of the seal member extends from the nut to a base side of the cylindrical portion. A waterproof structure for a gear unit for a meter cable, which is provided, and the cylindrical portion is tightly bound at the extended side end portion of the seal member. 2. The waterproof structure for a meter cable gear unit according to claim 1, wherein the cylindrical portion of the gear unit is formed so that the rear end is located rearward of the vehicle body with respect to the maximum diameter portion of the lower tube of the front fork. Waterproof structure of cable gear unit.