JP2003034282A - Connecting structure of gear unit for meter cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent protrusions from being damaged even if the protrusion of a gear unit and that of a hub are in contact with each other in installing the gear unit to the hub. SOLUTION: A cum face is formed on an edge part of the first protrusion 31 of the hub 7 opposite to the gear unit 4 in the axial direction. Another cum face is formed on an edge part of the second protrusion 32 of the gear unit 4 opposite to the hub 7 in the axial direction. The two cum faces are provided with inclined surfaces which gradually extend facing each other in the axial direction as the hub keeps on rotating in one direction.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a meter cable gear unit connecting structure for connecting a meter cable gear unit to a hub of a front wheel of a motorcycle, for example.

[0002]

2. Description of the Related Art Conventionally, a speedometer of a motorcycle is connected to a hub of a front wheel via a gear unit and a meter cable, and rotation of the front wheel is decelerated and transmitted by the gear unit. The gear unit has a structure in which a reducer including a worm and a worm wheel is housed in a housing, and the housing is supported by an axle of a front wheel in a state where rotation is restricted, and the worm is rotatably supported by the axle. It is connected to the hub.
The worm wheel is rotatably supported by the housing so that the axial direction is oriented in the front-back direction of the vehicle body,
The meter cable is connected to the rear end.

The hub and the worm are connected to each other by two first projections projecting outward on the outer side of the hub and a radial direction on the inner side of the worm (side facing the hub). This is done by engaging two second protrusions protruding outward. The two protrusions are separately arranged on one side and the other side in the radial direction of the hub, and are meshed so that the second protrusion is located between the two first protrusions on the same plane. By rotating the hub with respect to the worm after the first protrusion and the second protrusion are meshed with each other in this manner, the front end face of the first protrusion in the rotation direction comes into contact with the second protrusion, Rotation is transmitted to the worm.

The work of connecting the worm to the hub is performed when the gear unit is laterally assembled to the hub. That is, the worm and the worm wheel are installed in the housing in advance, the rotational direction of the worm is determined so that the second projection of the worm is located between the two first projections, and the housing is gripped in this state. And the whole gear unit is assembled to the hub. At this time, the housing is attached to the hub side while penetrating the axle through the shaft hole of the worm.

[0005]

However, when the gear unit is assembled to the hub, the worm, which is not restricted in rotation, may rotate with respect to the housing.
In such a case, the position of the second protrusion of the worm may change from the initial position, and the second protrusion may come into contact with the first protrusion of the hub. When the gear unit is assembled to the hub with both protrusions facing each other in this way, the second protrusion protruding radially outward from the worm is damaged by the pressing force during assembly. I will end up. In order to proceed while confirming that the protrusions are not in contact with each other, it is necessary to judge the magnitude of the load (resistance) when pressing the housing, so the assembly work must be done carefully. However, the work efficiency decreases.

The present invention has been made to solve such a problem, and when the gear unit is assembled to the hub, the projection is damaged even if the projection of the gear unit and the projection of the hub are in contact with each other. It is an object of the present invention to provide a gear cable gear unit coupling structure that does not exist.

[0007]

In order to achieve this object, a connecting structure for a gear unit for a meter cable according to the present invention is provided with a hub projection on a first projection of the hub, the end surface of the hub facing the gear unit. A cam surface is formed of an inclined surface that gradually extends toward one side in the axial direction as it goes toward one side in the rotation direction, and the end surface of the second protrusion of the gear unit facing the hub in the axial direction is parallel to the cam surface. The cam surface is formed.

According to the present invention, when the gear unit is assembled into the hub, the second protrusion of the gear unit is pressed while the first protrusion of the hub is in contact with the first protrusion of the hub. The protrusion slides in the circumferential direction of the hub along the cam surface with respect to the first protrusion, and moves to a position adjacent to the first protrusion.

According to a second aspect of the present invention, there is provided a meter cable gear unit connecting structure according to the first aspect, wherein the second cam surface of the second projection is The hub is gradually inclined toward the rear side in the rotational direction of the hub so as to extend toward the center of the hub in the axial direction. According to the present invention, the front surface of the first projection of the hub in the rotational direction is formed wider than the rear surface, and the rear surface of the second projection pushed by the front surface during traveling is formed wider than the front surface.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a connecting structure for a gear unit for a meter cable according to the present invention will be described in detail below with reference to FIGS. FIG. 1 is a side view showing the front half of a motorcycle that employs a gear unit connection structure according to the present invention, FIG. 2 is a sectional view taken along the line II-II of the hub and gear unit in FIG. 1, and FIG. 3 is a part of the hub. Is a side view showing the drawing, which is drawn as viewed from the gear unit side.
FIG. 4 is a side view of the gear unit, FIG. 5 is a sectional view taken along the line VV of the worm wheel portion in FIG. 4, FIG. 6 is a front view of the worm, and the same drawing is drawn from the hub side. Figure 7
Is a plan view of the worm, in which (a) shows a state where the protrusions face each other, (b) shows a state where the protrusions are in contact with each other, and (c) shows a state where the protrusions are pressed against each other. The worm is rotating, the figure (d) shows the gear unit attached to the hub, and the figure (e) shows the running state. In FIG. 7, the member on the hub side is depicted by a chain double-dashed line.

In these figures, the reference numeral 1 indicates a motorcycle according to this embodiment. In this motorcycle 1, a gear unit 4 for a meter cable is mounted on an axle 3 of a front wheel 2, and a rotation of the front wheel 2 is transmitted to a speedometer 6 by a meter cable 5 having a front end connected to the gear unit 4. In FIG. 1, reference numeral 7 is a hub of the front wheel 2, 8 is a front fork, 9 is a steering handle,
Reference numeral 10 is an engine, and 11 is a leg shield.

The hub 7 supports the rim 2a by spokes (not shown), and as shown in FIG.
Bearings 12 and 13 are rotatably supported on the axle 3. The axle 3 is supported and fixed to the lower left and right tubes 8a of the front fork 8. The hub 7 has a brake disk 14 fixed to the right side (left side in FIG. 2) of the vehicle body by a fixing bolt 15, and the gear unit 4 is connected to the left side end of the vehicle body.

The gear unit 4 is shown in FIGS.
As shown in FIG. 5, the housing 21 and the housing 2
1 and a speed reducer 22 provided inside the axle 3
Is arranged between the hub 7 and the lower tube 8a on the left side of the vehicle body of the front fork 8. The housing 2
1, the end portion on the hub 7 side is formed into a cylindrical shape, and the cylindrical portion 2
The axle 1 is supported by the axle 3 via a sleeve 23 in a state in which 1a is located on the outer peripheral side of the inner cylinder 7a of the hub 7. A seal member 24 is interposed between the cylindrical portion 21a and the inner cylinder 7a of the hub 7. In addition, this housing 21
Is a lower tube 8a on the left side of the vehicle body of the front fork 8.
Is engaged with, and rotation is restricted by this engaging portion.

The speed reducer 22 is rotatably supported by the sleeve 23 and is connected to the hub 7 by an engaging structure described later, and the worm 25 is rotatably supported by the housing 21 and meshed with the worm 25. It is constituted by the worm wheel 26. As shown in FIG. 5, the worm wheel 26 is formed in a rod shape and is supported by the housing 21 so as to extend in the front-rear direction of the vehicle body, and the meter cable 5 is attached to the connecting piece 26a integrally formed at the rear end portion.
Are connected.

As shown in FIGS. 2 and 3, the engagement structure for connecting the worm 25 and the hub 7 has two first protrusions which are provided on the left end of the vehicle body of the hub 7 so as to project outward. The protrusions 31, 31 and two second protrusions 32, 32 projecting radially outward from the worm 25, as shown in FIG.
Are positioned on the same plane, and the first projection 31 of the hub 7 presses the second projection 32 of the worm 25 in the rotation direction of the hub 7. Two first protrusions 3 on the hub 7
As shown in FIG. 3, 1 is an arcuate shape when viewed from the axial direction of the hub 7, and is formed so as to be point-symmetric with respect to the axial center of the hub 7. The axis is indicated by point C in FIG.
Flat pressing surfaces 31 a are formed on both ends of the first projections 31 in the circumferential direction of the hub 7.

The second protrusion 32 of the worm 25 has a flange 25 formed on the worm 25 so as to face the hub 7.
It is formed at two locations on the diameter of a, and pressure receiving surfaces 32a parallel to the pressing surface 31a are formed at both ends of the worm 25 in the circumferential direction. As shown in FIG. 7, the axial end faces of the first protrusions 31 facing the gear unit 4 and the axial end faces of the second protrusions 32 facing the hub 7 have a rotation direction of the hub 7. The cam surface is formed by an inclined surface that gradually extends toward one side in the axial direction toward one side. The cam surface of the first protrusion 31 is indicated by reference numeral 33, and the cam surface of the second protrusion 32 is indicated by reference numeral 34. The direction in which these cam surfaces 33, 34 incline gradually increases toward the rear side (the right side in FIG. 7) of the rotational direction of the hub 7 and the center of the hub 7 in the axial direction (the upper side in FIG. 7).
It is a direction extending toward.

The gear unit 4 thus constructed is mounted on the axle 3 when the front wheel 2 is assembled to the front fork 8. The gear unit 4 should be installed beforehand with the worm 25
The housing 21 in which the worm 2 and the worm wheel 26 are attached is gripped, and the worm 2 is attached to the sleeve 23 fitted into the axle 3.
5 and the housing 21 are inserted in this order. Conventionally, the second protrusion 3 of the worm 25 is in the middle of this work.
Although it was necessary to rotate the worm 25 so as not to abut the first protrusion 31 of the hub 7, this operation is not necessary in the gear unit 4 according to this embodiment.

As shown in FIGS. 7A and 7B, this is because the second protrusion 32 of the worm 25 contacts the first protrusion 31 of the hub 7 at the end of the mounting process of the gear unit 4. By pressing the first protrusion 31 in the axial direction of the hub 7, the second protrusion 32 moves along the cam surfaces 33 and 34 with respect to the first protrusion 31, as shown in FIG. 7C. Hub 7
Because it slips in the circumferential direction. In this way, the second protrusion 32
Sliding causes the worm 25 to rotate with respect to the hub 7, and as shown in FIG.
And moves to a position adjacent to the protrusion 31. As a result, the first
The gear unit 4 can be easily assembled to the hub 7 without performing any operation for avoiding the second protrusion 32 coming into contact with the protrusion 31.

After the gear unit 4 is assembled to the hub 7 as described above, the hub 7 rotates in the forward direction together with the front wheel 2 so that the first protrusion 31 of the hub 7 and the second protrusion 32 are attached to the hub 7. Abutting from the rear in the rotation direction of {Fig. 7
See (e)}. During traveling, this contact state is maintained, and the rotation of the front wheel 2 is transmitted from the hub 7 to the worm 25 via the first protrusion 31 and the second protrusion 32, and by the worm 25 and the worm wheel 26. After being decelerated, it is transmitted to the speedometer 6 by the meter cable 5.

In this embodiment, the cam surfaces 33, 34 of both the projections 31, 32 are gradually inclined toward the center of the hub 7 in the axial direction toward the rear side in the rotation direction of the hub 7. Therefore, the first protrusion 3 of the hub 7
1, the front surface in the rotational direction (the surface on the left side in FIG. 7) is formed wider than the rear surface, and the rear surface (the surface on the right side in FIG. 7) of the second protrusion 32 pushed by the front surface during traveling is also formed wider than the front surface. . Therefore, when traveling, the first
It is possible to widely disperse the stress generated when the protrusion 31 of pressing the second protrusion 32 presses the second protrusion 32.

[0021]

As described above, according to the present invention, when the gear unit is assembled into the hub, the first projection of the hub is pressed against the second projection of the gear unit, thereby pressing the second projection of the gear unit. The pressing force causes the second protrusion to slide in the circumferential direction of the hub along the cam surface with respect to the first protrusion and move to a position adjacent to the first protrusion. Therefore, it is possible to prevent the pressing force from concentrating on both the protrusions, so that it is possible to provide a connecting structure of the meter cable gear unit in which the protrusions are not damaged when the gear unit is assembled to the hub.

As described above, according to the present invention, the front surface of the first projection of the hub in the rotational direction is formed wider than the rear surface, and the rear surface of the second projection pushed by the front surface during traveling is wider than the front surface. It is formed. Therefore, the stress generated when the first protrusion presses the second protrusion of the gear unit during traveling is widely dispersed to both protrusions, and the contact portions of both protrusions are less likely to be worn, so that the connection with high durability is achieved. The structure can be realized.

[Brief description of drawings]

FIG. 1 is a side view showing a front half of a motorcycle that employs a gear unit coupling structure according to the present invention.

FIG. 2 II-of the hub and gear unit in FIG.
It is a II sectional view.

FIG. 3 is a side view showing a part of the hub.

FIG. 4 is a side view of a gear unit.

5 is a sectional view taken along line VV of the worm wheel portion in FIG.

FIG. 6 is a front view of the worm.

FIG. 7 is a plan view of the worm.

[Explanation of symbols]

2 ... Front wheel, 3 ... Axle, 4 ... Gear unit, 5 ... Meter cable, 7 ... Hub, 21 ... Housing, 25 ... Worm, 26 ... Worm wheel, 31 ... First protrusion, 32
... second protrusions 33, 34 ... cam surface.

Claims (2)

[Claims] 1. A wheel drive hub is provided with a first drive projection protruding outward at an end portion of the wheel hub in the vehicle width direction, and a meter cable is provided on a front end surface of the first projection in the rotation direction of the hub. In a connecting structure of a gear unit for a meter cable, in which a second projection protruding outward in the radial direction is brought into contact with the worm of the gear unit for gears, in an axial end surface of the first projection facing the gear unit. A cam surface formed of an inclined surface that gradually extends in one axial direction as it goes in one rotational direction of the hub.
A connecting structure for a gear unit for a meter cable, in which a cam surface parallel to the cam surface is formed on an end surface of the projection of the shaft facing the hub in the axial direction. 2. The connecting structure for a gear unit for a meter cable according to claim 1, wherein the cam surface of the second protrusion is
A connecting structure for a gear unit for a meter cable, which is gradually inclined toward a center in the axial direction of the hub as it goes rearward in the rotation direction of the hub.