JPH05178255A - Cassette type head set - Google Patents

Abstract

PURPOSE:To facilitate the assembly of a steering head structure by assembling an outer cylinder, inner cylinder, and bearings in one set, so that the inner cylinder and bearings are assembled on a head pipe, together with the outer cylinder, through the assembly operation for the head pipe of the outer cylinder. CONSTITUTION:A cassette type head set H is equipped with an outer cylinder 15 which is internally fitted with a head pipe 3, inner cylinder 16 which is externally fitted with a fork stem 1 formed integrally with the left and right fork stems 12 in pair, and bearings 19 and 21 which are arranged between both the cylinders 15 and 16 and connect both the cylinders 15 and 16 in relatively turnable manner and regulate the relative shift in the axial directions of both the cylinders 15 and 16. By the assembly operation of the outer cylinder 15 for the head pipe 3 by a lock nut 23, both the cylinders 15 and 16 and bearings 19 and 21 are assembled in one set, so that the inner cylinder 16 and the bearings 19 and 21 are assembled on the head pipe 3, together with the outer cylinder 15, and the bearings 19 and 21 for the fork stem 1 of the inner cylinder 16 are assembled on the fork stem 1, together with the inner cylinder 16.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to bearing means used for constructing a steering head structure for rotatably supporting front wheels of a bicycle or the like on a body frame. It can also be applied to motorized bicycles such as scooters and front wheel support structures for three-wheeled vehicles.

[0002]

2. Description of the Related Art To construct a steering head structure,
Conventionally, as shown in FIG. 9, a lower bearing portion 6 including a lower inner race 2 externally fitted to a fork stem 1, a lower outer race 4 internally fitted to a lower end portion of a head pipe 3, and a ball 5, and a head. An upper bearing portion 10 including an upper inner race 7 fitted inside the upper end of the pipe 3, an upper outer race 8 fitted outside the fork stem 1, and a ball 9.
Was equipped with.

[0003]

In the conventional steering head structure, a tightening nut and a lock nut are screwed and assembled to the upper end of a fork stem protruding upward from the upper outer race, and the tightening force of the tightening nut raises and lowers the nut. The contact pressure between the ball and the upper and lower races in the bearing is determined. If the tightening force of the tightening nut is weak, the bearing may rattle and the steering operation may become unstable, and the collision between the ball and the race may damage the sliding surface. It becomes heavy, and in some cases, the balls may make indentations on the sliding surface of the race to hinder smooth steering operation. Therefore, it is important to tighten and fix the tightening nut with an appropriate tightening torque. Therefore, in the actual assembly work, it is necessary to perform the nut tightening operation while confirming that there is no play and that the steering operation can be done lightly, that is, with the adjustment of the ball bearing, the assembly work of the steering head structure is compared. It was difficult and troublesome.
An object of the present invention is to make it possible to easily and easily assemble the steering head structure in a favorable turning adjustment state.

[0004]

In order to achieve the object, a cassette type headset according to the present invention has an outer cylinder fitted inside a head pipe, an inner cylinder fitted outside a fork stem, and an outer cylinder. The head of the outer cylinder is provided between the outer cylinder and the inner cylinder, includes a bearing that connects the outer cylinder and the inner cylinder in a relatively rotatable manner, and restricts relative movement of the outer cylinder and the inner cylinder in the axial direction. The inner cylinder and the bearing are assembled to the head pipe together with the outer cylinder by the assembling operation to the pipe, and the outer cylinder and the bearing are assembled to the front fork stem together with the inner cylinder by the assembling operation of the inner cylinder to the fork stem. In this state, the outer cylinder, the inner cylinder and the bearing are assembled.

[0005]

[Function] The outer cylinder, the inner cylinder, and the bearing are assembled in advance by adjusting the outer cylinder and the inner cylinder to a good rotation adjustment state in which the outer cylinder and the inner cylinder are smoothly rotated relative to each other without being twisted or loose. The assembling operation is performed on the head pipe and the fork stem so that the outer cylinder fits inside the head pipe and the inner cylinder fits outside the fork stem. Then, the outer cylinder, the inner cylinder, and the bearing are assembled into a set, and are assembled to the head pipe and the fork stem in the good rotation adjustment state at once, and the fork stem and the head pipe are operated by the outer cylinder, the inner cylinder, and the bearing. It is possible to assemble the steering head structure so that the steering head structure can be assembled in a smoothly rotating state without being twisted or loose.

[0006]

As the outer cylinder, the inner cylinder and the bearing are assembled as a set and the rotation adjustment is not required at the time of the assembly, the steering head structure can be rotated well. It was possible to assemble efficiently.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows the structure of a steering head portion for a bicycle. Reference numeral 1 denotes a fork stem fitted and fixedly supported on a shoulder bracket 11, and a pair of left and right fork braces 12, 12 for supporting a front wheel (not shown) are fixed to the left and right of the shoulder bracket 11. 3 is a head pipe which is one component forming a vehicle body frame, 13 is a handle stem, and 14 is an inclined cam body for internally fitting and locking the handle stem 13 to a fork stem. That is, the tilted cam body 14 and the handle stem 13 are displaced in the radial direction by screw driving, so that the handle stem 13 is crimped and fixed inside the tubular fork stem 1.

Reference numeral 15 denotes an outer cylinder fitted inside the head pipe 3, and the outer cylinder 15 is fitted to an inner cylinder 16 fitted outside the fork stem 1, and the relative positions of these cylinders 15 and 16 in the cylinder axis direction. A cassette-type headset H is configured by external fitting so as to be rotatable relative to each other in a state in which displacement is restricted. That is, the inner race portion 17 is provided at the lower end of the inner cylinder 16 and the outer race portion 18 is provided at the lower end of the outer cylinder 15.
Are formed respectively, and a large number of steering balls 19 are interposed between these race portions 17 and 18 to form a ball type bearing portion A. Each of the outer race portion 18 and the inner race portion 17 is formed with curved ball-shaped ball receiving portions 20, 20 for restricting the displacement of the steering ball 19 in both the up and down directions of the vehicle body, whereby the outer cylinder 15 and the inner cylinder are formed. 16 and 16 are integrated. Reference numeral 21 is a bush for forming a bearing portion at the upper end of the outer cylinder 15 and the inner cylinder 16. Reference numeral 22 denotes a rubber O-ring which seals dustproof and waterproof and prevents lateral deflection of the fork stem 1 with respect to the head pipe 3. The outer cylinder 15 has a flange portion 15a at the lower end thereof.
Is mounted by sandwiching the head pipe 3 with a lower lock nut 23 screwed to the upper end, and the inner cylinder 16 has its lower end 16a abutted against the shoulder bracket 11 and screwed to the upper end of the fork stem 1 It is attached to the fork stem 1 by tightening the nut 24. Therefore, as shown in FIG. 2, by removing the upper and lower lock nuts 24 and 23, the outer cylinder 15 can be extracted downward from the head pipe 3, and the fork stem 1 can be extracted downward from the inner cylinder 16. The fork stem 1, the headset H, and the head pipe 3 can be quickly separated, and if these operations are performed in the opposite manner, these three parts can be quickly assembled.

In the conventional ball type steering structure, since the bearing portion holds a large number of balls on the race surface by sandwiching them between the upper and lower races, it is unexpected due to the disassembly of the fork stem and the head pipe. In addition to the inconvenience that the balls may fall off and be easily lost, there is a work to put a lot of balls on the inner race by putting grease on them while assembling them so that they will not easily move on the inner race.
It was very troublesome and troublesome to replace the fork, for example, it was necessary to fit the fork stem and head pipe relative to each other while maintaining that state.
In the present invention, the headset is set in a state where the contents thereof are already satisfied, and therefore it is sufficient to simply assemble the headset. Therefore, when the fork is replaced with respect to the body frame, the inner cylinder and the fork stem can be attached / detached, and when the body frame is replaced with respect to the fork, the outer cylinder and the head pipe are replaced. It can be done by putting on and taking off. In addition, if the headset itself is replaced with one having a different size and diameter, modification such as changing the diameter of the head pipe or the fork stem becomes possible.

[Other Embodiments] Instead of the combination of the steering ball 19 and the bush 21, as shown in FIG. 3, there are two upper and lower bearing portions A of a type in which small balls 19 and 21 are used in the headset H. In preparation for this, both the outer cylinder 15 and the inner cylinder 16 may be made of straight pipe material. Alternatively, instead of using the balls, only the bush may be used. Therefore, these small balls and bushes are called bearings 19 and 21. It is also conceivable that the flange 15a of the outer cylinder 15 and the flange formed at the lower end of the head pipe 3 are connected and fixed by bolts. As means for fixing the outer cylinder 15 and the inner cylinder 16 to the head pipe 3 or the fork stem 1 so as not to shift in the axial direction, various means such as caulking and lock pins are adopted in addition to the nuts 23 and 24. Good.

A steering head unit having the structure shown in FIG. 4 may be used. That is, in the structure shown in FIG. 1, the intermediate ring 18a is fitted on the inner peripheral surface of the outer race portion 18, and a large number of steering balls 1 are evenly provided over the entire circumference between the intermediate ring 18a and the inner race portion 17.
9 are arranged. Each of the intermediate ring 18a and the inner race portion 17 is formed with a ball receiving portion 20, 20 having a semicircular cross section for restricting the positional deviation of the steering ball 19 in the axial direction of the fork stem.
The outer race portion 18 and the inner race portion 17, that is, the outer cylinder 15 and the inner cylinder 16 are integrated by being assembled in a state in which the outer cylinder portion 15 and the inner cylinder portion 16 are integrated, and these become a unitized bearing portion A.

As shown in FIG. 5, the bearing A may be a steering head having a structure in which a commercially available bearing unit is used. That is, the bearing unit 21 capable of receiving the thrust load is attached to the upper end portion thereof, and the bearing unit 19 for supporting only the radial load is attached to the lower end portion thereof. The upper end of the inner cylinder 16 is step-processed, one end of the bearing unit 21 is received by the radial surface of the step, and the other bearing unit 21 is disposed via the spacer ring 28. Both bearing units 21 are fixed between the inner cylinder 16 and the outer cylinder 15 by an inner bearing pressing ring 26 screwed into the outer cylinder 15 and an outer bearing pressing ring 27 screwed into the outer cylinder 15. In order to receive the lower bearing unit 19, the lower end portion of the inner cylinder 16 is similarly stepped, and the bearing retainer 29 that is screwed into the outer cylinder is also provided.
It is firmly fixed by. Again, the outer tube 1
5 is attached to the head pipe 3 by sandwiching the head pipe 3 with the flange portion 15a at the lower end thereof and the first lock nut 23 screwed to the upper end thereof, and the inner cylinder 16 has its lower end 16a attached to the shoulder bracket 11. It is attached to the fork stem 1 by abutting and tightening the second lock nut 24 screwed to the upper end of the fork stem 1. FIG. 6 shows a modification of the headset H shown in FIG. 5, in which a resin bush 19 is used as a slide bearing instead of the lower bearing unit 19. The other points are basically the same as those shown in FIG.

As shown in FIG. 7, a unitized cassette-type headset H configured by vertically and vertically arranging two types of balls 19 and 21 of two types, large and small, is adopted as the lower bearing portion A. The steering head part having the above structure may be used. That is, the inner cylinder 16 is the fork stem 1
It is formed with a short length to surround only the lower area of
The outer cylinder 15 is also formed with a short length that matches the inner cylinder 16. A ball receiving surface 16b for receiving the larger ball 19 on the outer peripheral surface of the inner cylinder 16;
Further, a ball receiving surface 16c for receiving the smaller ball 21 is formed at an axial interval from this. Similarly, a ball receiving surface 15b for receiving the larger ball 19 and a ball receiving surface 15c for receiving the smaller ball 21 axially apart from the ball receiving surface 15b are formed on the inner peripheral surface of the outer cylinder 15. The inner cylinder 16 is formed so as to correspond to the ball receiving surfaces 16b and 16c. As is clear from the drawings, the bearing portion A can receive both thrust load and radial load due to the shape of the ball and the ball receiving surface. The outer cylinder 15 is provided with a flange portion that extends in the radial direction to form the ball receiving surface 15b, and this flange portion is used for mounting the head pipe 3 as the headset H. A spacer pipe 30 that is disposed in abutting relation with the upper end surface of the inner cylinder 16 and surrounds the fork stem 1.
The inner cylinder 16 is attached to the fork stem 1 by pressing it downward with a lock nut 23 screwed onto the upper end of the fork stem 1.
A flanged bush 25 functioning as a slide bearing is inserted between the lock nut 23 and the upper end portion of the head pipe 3 to regulate a radial gap between the fork stem 1 and the head pipe 3 and to rotate them relative to each other. Is possible. It is also possible to connect the spacer pipe 30 and the inner cylinder with a screw or the like. FIG. 8 shows a modified example of the headset H shown in FIG. 7. In the headset H shown here, the positions of the larger ball 19 and the smaller ball 21 are opposite in the axial direction. This is different from that shown in FIG. With this change, the positions of the ball receiving surfaces 15b and 15c formed on the outer cylinder 15 and the inner cylinder 16
The positions of the ball receiving surfaces 16b and 16c formed on the are also changed.

Although various embodiments have been described above, the cassette type headset H is divided into the upper and lower integrated type shown in FIGS. 1 to 6 and the unit type shown in FIGS. 7 and 8. Be done. That is, the upper and lower integrated type can form the steering structure by itself, and the assembly is easier and easier than the unit type, and the unit type uses this as the upper or lower bearing part. Alternatively, the steering structure is formed by providing the upper and lower parts, and each has an advantage that it is excellent in compactness and versatility as a component.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of a steering head section.

FIG. 2 is an exploded perspective view showing a structure of a steering head unit.

FIG. 3 is a cross-sectional view showing a first different structure of the steering head portion.

FIG. 4 is a sectional view showing a second different structure of the steering head portion.

FIG. 5 is a sectional view showing a third different structure of the steering head portion.

FIG. 6 is a sectional view showing a fourth different structure of the steering head portion.

FIG. 7 is a sectional view showing a fifth different structure of the steering head portion.

FIG. 8 is a sectional view showing a sixth different structure of the steering head portion.

FIG. 9 is a cross-sectional view showing the structure of a conventional steering head section.

[Explanation of symbols]

 1 Fork stem 3 Head pipe 15 Outer tube 16 Inner tube 19,21 Bearing

Claims (1)

[Claims] 1. An outer cylinder (15) internally fitted to a head pipe (3), an inner cylinder (16) externally fitted to a fork stem (1), and the outer cylinder (15) and the inner cylinder (). 16) arranged between the outer cylinder (15)
Bearings (19), (21) for connecting the outer cylinder (16) and the inner cylinder (16) so as to be rotatable relative to each other and for restricting relative movement of the outer cylinder (15) and the inner cylinder (16) in the axial direction.
The inner cylinder (1) is provided by an assembling operation of the outer cylinder (15) to the head pipe (3).
6) and the bearings (19), (21) are assembled to the head pipe (3) together with the outer cylinder (15), and the inner cylinder (16) is assembled to the fork stem (1). The outer cylinder (1
5) and the bearings (19) and (21) are assembled to the front fork stem (1) together with the inner cylinder (16), the outer cylinder (15), the inner cylinder (16) and the bearing (19). ), (21) assembled cassette type headset.