JPH0410157Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to a steering device for a small vehicle equipped with a bar-shaped handle, such as a motorcycle or a tricycle.

Prior Art In a steering device for a small vehicle equipped with a rod-shaped handle, a top bridge and a bottom bridge that support a front fork at both ends are located above and below the head pipe, respectively, and a handle rotation shaft integrally connected to the bottom bridge is located above and below the head pipe, respectively. The handle is rotatably fitted into the head pipe via a pair of upper and lower bearings, and a top bridge is fixed to the upper end of the handle rotation shaft. The handle rotation shaft and the top bridge are connected by screwing tightening nuts at the upper and lower positions with the top bridge sandwiched between the handle rotation shaft passing through the central opening of the top bridge, and then tightening the top bridge with both tightening nuts. It is done by twisting. The tightening nut located below the top bridge presses a bearing (angular contact ball bearing or angular contact roller bearing) fitted into the upper part of the head pipe, and this pressing force, that is, the tightening axial force of the lower tightening nut By adjusting the rotational friction resistance of the upper and lower bearings, it is possible to change the rotational friction resistance of the upper and lower bearings. In other words, the frictional resistance (rotational friction torque) around the handle rotation axis can be changed by adjusting the tightening axial force of the lower tightening nut.

Problems that the invention aims to solve By the way, while the vehicle is running, torsional force is repeatedly applied to the pair of left and right front forks and the top and bottom bridges that hold them, causing the top and bottom bridges to twist around the steering wheel rotation axis. There will be a relative rotational displacement. At this time, since the handle rotation shaft and the bottom bridge are firmly connected together, the top bridge rotates relative to the handle rotation shaft and then returns to its original state. Since the lower tightening nut is integrated with the top bridge under strong pressure by the tightening force of the upper tightening nut, it moves together with the top bridge and moves relative to the handle rotation axis. Since this movement is a repetition of displacement and restoration, it does not substantially affect the frictional resistance around the steering wheel rotation axis. However, if the lower tightening nut moves only in one direction, it may be difficult to use the vehicle for a long period of time. The frictional resistance around the handle rotation axis changes accordingly.

Means and Effects for Solving the Problems The purpose of the present invention is to reliably prevent changes in frictional resistance around the rotational axis of the handle by preventing relative rotational displacement between the tightening nut and top bridge that contact the bearing. At the point.

In the steering device of the present invention, a rotation prevention plate is interposed between the top bridge and the tightening nut screwed onto the steering wheel rotation shaft by pressing the upper bearing of the upper and lower bearings that support the steering wheel rotation shaft, The arcuate protrusion of the rotation prevention plate is bent and locked along the peripheral wall of the top bridge, and
Since the locking claw of the rotation prevention plate is bent and locked in the groove of the tightening nut, the rotation prevention plate is integrally fixed to the top bridge and is locked to the rotation prevention plate. A tightening nut is also integrated into the top bridge, and the tightening nut can be rotationally displaced in conjunction with the top bridge.

Embodiment Hereinafter, an embodiment of the present invention shown in FIGS. 1 and 6 will be described.

FIG. 1 shows a steering device 10 for a motorcycle.
is shown as a longitudinal cross-sectional view as seen from the front side of the vehicle body (however, the left side is omitted because it is symmetrical between the left and right sides), and FIG. 2 is a cross-sectional view taken along the - line in FIG. 1. The upper and lower bearings (angular contact roller bearings) 14, 1 pass through the inside of the head pipe 12.
The handle rotation shaft 18, supported at 6, is press-fitted into the central opening of the bottom bridge 20 and is firmly connected to the bottom bridge 20. The upper end of the handle rotation shaft 18 passes through the central opening of the top bridge 32, and the handle rotation shaft 18 and the top bridge 32 are tightened by the tightening force of the tightening nuts 22, 24 screwed onto the handle rotation shaft 18.
are integrated.

The tightening axial force of the tightening nut 24 acts on the bearing 14 via the seal S, and both bearings 14,
Since the bearings 16 are housed in the upper and lower stepped portions of the head pipe 12, the tightening axial force also acts on the bearings 16. The tightening nut 24 has a plurality of grooves 25 along the central axis direction on its outer periphery (see FIGS. 3 and 4. However, FIG. 4 is a sectional view taken along the line -- in FIG. 3). ).

In addition, tightening nut 24 and top bridge 3
A rotation prevention plate 26 is inserted between 2,
The three locking claws 28 are inserted into the three grooves 25 of the tightening nut 24, and the arcuate jaws 31 are in circumferential contact with the peripheral wall of the top bridge 32. The shape of the rotation prevention plate 26 before assembly is as shown in FIGS. 5 and 6 (FIG. 6 is a cross-sectional view taken along the - line in FIG. 5).
The arc-shaped protrusion 30
The jaw piece 31 is bent along the peripheral wall of the top bridge 32 after assembly.

The top bridge 32 and the bottom bridge 20 are connected to the front fork 3 at both ends thereof.
A handle pipe 36 is fixed to the top of the top bridge 32.

In this way, in the steering device 10 of this embodiment, the rotation prevention plate 26 is inserted between the tightening nut 24 and the top bridge 32, and the locking pawl 2 is inserted between the tightening nut 24 and the top bridge 32.
8. Since the jaw pieces 31 are respectively locked to the tightening nut 24 and the top bridge 32, the tightening nut 24 always moves together with the top bridge 32 with respect to the handle rotation axis 18. Therefore, the tightening nut 24 does not rotate only in one direction with respect to the handle rotation shaft 18, and the bearing 14,
The tightening axial force acting on 16 does not change from the initial state. Note that due to the relative rotational displacement between the top bridge 32 and the bottom bridge 20, the amount of relative rotational displacement that repeatedly occurs between the handle rotating shaft 18 and the top bridge 32 (and the tightening nut 24) is extremely small, and due to this displacement, the bearing 14, The tightening axial force for 16 is not affected.

Effects of the Invention As is clear from the description of the embodiments above, in the steering device of the present invention, the upper bearing of the upper and lower bearings that support the steering wheel rotation shaft is pressed and screwed onto the steering wheel rotation shaft. A rotation prevention plate is interposed between the tightening nut and the top bridge, and the arcuate protrusion of the rotation prevention plate is bent and locked along the peripheral wall of the top bridge, and the locking claw of the rotation prevention plate is engaged. Since the tightening nut is bent and locked in the groove of the tightening nut, the tightening nut is integrally connected to the top bridge via the rotation prevention plate, and no matter what rotational force is applied to the handle rotation shaft, The tightening nut is firmly fixed and acts as a lock, and the tightening axial force of the tightening nut does not change from its initial state.

In addition, the present invention does not require a separate nut that contacts the bottom surface of the top bridge in addition to the tightening nut, and does not require any special processing on the handle rotation axis, which reduces the number of parts and simplifies the structure. This makes it possible to reduce costs.

[Brief explanation of the drawing]

Fig. 1 is a vertical cross-sectional view of a steering device for a motorcycle according to an embodiment of the present invention as seen from the front side of the vehicle body, Fig. 2 is a cross-sectional view taken along the - line in Fig. 1, and Fig. 3 is a cross-sectional view taken along the - line in Fig. 3 used in the above-mentioned steering device. A front view of the tightening nut shown in Fig. 4 is the − in Fig. 3.
5 is a front view of the rotation prevention plate used in the steering device, and FIG. 6 is a sectional view taken along the line -- in FIG. 5. DESCRIPTION OF SYMBOLS 10... Steering device, 12... Head pipe, 14... Bearing, 16... Bearing, 18... Handle rotation shaft, 20... Bottom bridge, 22...
...Tightening nut, 24...Tightening nut, 2
6... Rotation prevention plate, 28... Locking claw, 31... Jaw piece, 32... Top bridge, 34... Front fork.

Claims (1)

[Claims for Utility Model Registration] A top bridge and a bottom bridge that support a front fork at both ends are located above and below the head pipe, respectively, and a handle rotating shaft integrally connected to the bottom bridge supports a pair of upper and lower bearings. In a small vehicle in which a top bridge is rotatably fitted into a head pipe through a head pipe and a top bridge is fixed to an upper end of the handle rotation shaft, the top bridge is coupled to a tightening nut that is screwed onto the handle rotation shaft and presses the upper bearing. A rotation prevention plate is interposed in between, and the arcuate protrusion of the rotation prevention plate is bent and locked along the peripheral wall of the top bridge, and the locking claw of the rotation prevention plate is bent into the groove of the tightening nut. A steering device for a small vehicle, characterized in that the steering device is locked in place.