JPS596434A - Free-wheel for bicycle and assembling method thereof - Google Patents

Abstract

PURPOSE:To massproduce products having a uniform rotational characteristic by an automated machine, by completing alignment of bearing when the ball pushing lid is put in contact with steel balls and by performing fixation of this lid by metal depositing. CONSTITUTION:No.1 group of steel balls 24 are interposed between No.1 internal ball receptacle surface 9 of a core 1 and No.1 external ball receptacle surface 18 of a free gear 15. This core 1 and free gear 15 are assembled previously. After placing No.2 group of steel balls 25 on No.2 external ball receptacle surface 19 of the free gear 15, a ball pushing lid 21 is fitted on the cylindrical part 13 of the core 1 and slided inward in the axial direction. Then this ball pushing lid 21 put in contact with No.2 group of steel ball 25, and when no more sliding is possible, laser beam 3 focused thin is radiated to the contact part 5 of core 1 with lid 21 to joint this part 5 by depositing.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bicycle freewheel, and more specifically, to a bicycle freewheel.
This eliminates the need for adjusting the screw cover, which was inefficient in the assembly of conventional bicycle freewheels, and makes it possible to assemble products with uniform rolling performance using automatic machines. This invention relates to a rotating heavy freewheel with an improved structure and a method for assembling the same.

The conventional general structure of a bicycle freewheel is as shown in FIG.

In the figure, (a) shows a free gear having sprocket teeth (b) on the outer periphery, ratchet teeth (c) on the inner periphery, and a pair of annular outer receiving surfaces (d) and (e) formed on both sides of the sprocket teeth (b). , which is rotatably supported on the outside of the core (f). Core (f) outer periphery marking outer ball receiving surface (d) flange (h) with opposing inner ball receiving surface (g); Screw the ratchet cover (j), which has an adjacent thick part (1) into which a ratchet pawl (not shown) is to be embedded, and an inner spherical receiving surface (m) opposite to the outer spherical receiving surface (e). It has a threaded shaft (k) for mating, and a center hole (m) in which a thread (1) to be threaded into the hub body (not shown) is carved in the inner peripheral part. Note that (p) and (q) are the opposing outer and inner ball bearing surfaces (a
, ) (g) and (e) (n) are held under pressure to reduce the relative rotation between the core (f) and the free gear (a+,!:) to 0.
A group of steel balls with T function is shown.

In this configuration, in order to obtain proper rotational performance of the free gear (a), the steel ball groups (p) and (q) are pressed between the ball receiving surfaces (d), (g), (e), and (n) with an appropriate pressing force. It is necessary to hold it under pressure. If this clamping force is too large, the free rotation of the free gear (f) will not be guaranteed due to the formation of impressions on each ball bearing surface (d), (g), (e), (n), and conversely, the clamping force will be too weak. Seven ball receiving surfaces (d) (g) (e)
A gap is created between (n) and the steel ball ω) (q), and the core (a) and free gear (f) become loose with each other in the hub axis direction.

By the way, the steel ball group ω) (q) as described above was provided on the core (f) to adjust the appropriate IEK clamping between each ball receiving surface (d) (g) (e) (n1). Spiral part (k)
The upper adjustment is made by threading the screw M(j), but this adjustment is very time-consuming and requires highly skilled skill. After adjusting the screw cap (j
) must be screwed in as much as possible to ensure that the lid (j) is locked. That is, the inner end wall of the screw cap (j) is attached to some fixed object (for example, the outer end wall (r) of the thick portion (1) in the core (f)).
must be screwed in until it is pressed firmly. In this way, in order to properly hold a ball between the ball receiving surfaces (d) (g) (θ) (n) with the screw cap (j) screwed in, conventional methods , as shown in FIG. 7, a plurality of thin tone plates (6) are interposed between the inner end wall of the screw cap (j) and the outer end wall (r) of the thick portion (1), and By adjusting the number of adjustment plates (S), the position of the screw lid (j) in the axial direction was finely adjusted. Since there are variations due to errors in the dimensions of each part, the assembler should check the rotation of the 7th gear (a) with the screw cap (j) screwed in as much as possible, and check the tone plate. The extremely troublesome assembly and adjustment work of repeatedly tightening and removing the screw caps (j) while adjusting the number of pieces (8) had to be carried out for each of the seven lee wheels.

SUMMARY OF THE INVENTION An object of the present invention is to provide a bicycle freewheel and a method for assembling the same, which are structurally improved so as to solve the above-mentioned problems in assembling the conventional freewheel at once. .

That is, the present invention has a core having a center hole with a thread for forming a hub body K a M, and a free gear disposed in a mantle-like manner on the core. A pair of bearing structures constituted by ball receiving surfaces formed between the core and the free gear so as to sandwich these steel balls, and a one-way rotation transmission mechanism allow the free gear to be aligned with respect to the core. In a bicycle freewheel configured to be supported rotatably only in one direction, the outer cylindrical shape of the core is screwed or fitted into an annular ball-pushing lid having a ball-receiving surface on the inner part. The direction is moved inward in the axial direction on the outer circumference of the part,
The ball-receiving surface of the several-ball push lid contacts a plurality of steel balls arranged in an annular manner on the ball-receiving surface of the inner peripheral surface of the free gear, and the several-ball push lid moves axially inward on the cylindrical portion. When the number of balls is no longer available, the contact portion between the several-ball pressing lid and the core is welded to fix the several-ball pressing lid.

The present invention is based on the traditional concept in freewheel assembly, in which the screw cap is screwed in as much as possible while adjusting the number of adjustment plates interposed between the screw cap and the outer wall of the thick part of the core. It is something that has been defeated. That is, in the present invention, a ball pusher cap is used in place of the conventional screw cap, and a large ball is moved inwardly in the direction of the hub axis over a cylindrical portion on the outer side of the core, and several balls are pressed. The alignment of the bearing structure is completed when the ball receiving surface shaped inward of the push lid comes into contact with the steel ball placed in advance on the ball receiving surface J: on the free gear side. By welding the contact portion between the ball pusher cover and the core, the ball pusher cover is fixed in an appropriate position. Therefore, when the bicycle freewheel according to the present invention is used, the ball pusher cover can be fixed in place. Since it is not fixed by screw means,
The troublesome adjustment work required in the past, which requires a tone plate, is completely unnecessary, and it becomes possible to produce products with a constant rotational performance using automatic machines with no fuss.

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows the process of continuously welding the contact portion between the core (1) and the ball-pushing lid (2) in the freewheel (A) using a laser beam (3). In the freewheel shown in the figure, after the ball pusher cover (21) is fitted into the core fil, an appropriate pressing force is applied to the ball pusher cover (21) using an appropriate rank/means (4) while the ball is being pressed. The fitting contact portion (5) of the ball pusher cover (1) and the ball pusher cover (1) are welded together.

The internal structure of such a freewheel (A) is shown in FIGS. 2 and 3. The core (1) has a generally cylindrical shape and has a center hole (7) with a thread (6) for screwing into the hub body (not shown), and a hole (7) on its outer periphery. 1. A flange (10) provided with an inner receiving surface (9) forming a part of the bearing structure (8), and a ratchet mechanism adjacent to the flange (lO) and serving as a one-way rotation transmission mechanism. ! Thick wall part t+21 for embedding the ratchet pawl (tta) of II)
The ratchet pawl [+1] tri is always biased in the rising direction using a ring spring (14) as shown in FIG. The free gear (15j) is rotatably supported in only one direction on the outside of the core i11 by a pair of bearing structures, that is, first and second bearing structures (80e and a ratchet mechanism (11). 7
The re-gear (11 has sprocket teeth (11j) formed on its outer periphery, and a pair of outer spherical bearing surfaces, i.e., the first Outer ball receiving surface! I8) and second outer ball receiving surface (19)
are provided around the vicinity of both ends in the axial direction, and ratchet teeth are formed in the middle part in the axial direction to face the thick portions (12) of the core fil.

Reference numeral (21) has a second inner spherical receiving surface (2'4) forming a part of the second bearing structure, and the core fi
The ball-pushing lid fitted to the cylindrical portion (1) is shown.

Moreover, the code (23) is the cylindrical part (13) of the middle P (1).
The welded portion formed at the contact portion between the ball-pushing lid (21) and the ball-pushing lid (21) is shown.

Further, reference numeral (24) indicates the 114th ball group interposed between the first inner ball receiving surface (9) and the first outer ball receiving surface (118), and reference numeral t26) indicates the second inner ball receiving surface (2). and the second outer ball receiving surface (1
9) The second steel ball group interposed therebetween is shown.

In the bicycle freewheel (A) according to the present invention,
The most characteristic point is that the outer end wall (12) of the thick part (12) of the core
2a),! : It is possible to assemble a tone plate as shown in FIG. 7 between the inner end walls (21a) of the ball pusher cover (21) without having to press any pressure. Therefore, the ball-pushing lid ρl) according to the present invention does not require a screw-on lid that is fixed by tightening the screws to the maximum as in the conventional example, but is simply a cylindrical lid provided on the outer part of the core +11. What is necessary is just to form it so that it can fit into part (+3). The degree of this fitting is not particularly limited, but it is appropriate to have a degree of tightness that prevents unscrewing. in this way,
In the bicycle freewheel according to the present invention, the process of threading the cylindrical part (13) of the core ++ and the ball pusher cover (
21) There is no need for a thread cutting process on the inner periphery, and there is no need for a tension plate.

Next, referring to FIGS. 4 and 5, a method for assembling the bicycle freewheel (A) according to the present invention will be described.

A first steel ball group is installed between the first inner ball receiving surface (9) formed on the inner end of the core +1+ and the free gear (first outer ball receiving surface 8 formed on the inner end of the inner periphery of 15j). (24), the core (1) and the free gear (15) of iIJ are combined in advance, and the second outer spherical receiving surface (+9 ) K2′lIA sphere group (
After placing the fireflies, fit the ball pusher into the cylindrical part (13) provided on the outer part of the core (1) and press it into the shaft using a suitable pressing means such as a flange (4). Slide it inward (Figure 4). Then, when the mJ ball pusher lid Q1) contacts i'1 glycoside2 steel ball group i2ω and cannot slide any further, the laser beam (3) converged into a narrow shape
The contact part (5) between the core (1) and the ball press cover (21)
This part (5) is welded by irradiating it to the surface (see Fig. 5 and Fig. 1). The condition of the bearing structure is completely correct as soon as the ball pusher lid (21) comes into contact with the second ball group +25).

If the welding is carried out by irradiating a finely focused laser beam as shown in the example shown in the figure, the metal of the core and the ball-pushing lid will only be locally melted, so thermal diffusion will be small and the process will be completed in a short time. cooled down. Therefore, there is no inconvenience such as the heat-treated portions applied to each ball receiving surface being adversely affected by the heat generated by the welding and becoming softened.

The welding may be performed using laser beats as described above, or may be performed by spot welding, which generates less heat. That is, thin plate portions (not shown) that can come into contact with each other when assembled are formed on both the ball-pushing lid H and the core (1), and these thin plate portions are spot welded at a plurality of locations.

In addition, in the above embodiment, the cylindrical part (131i) provided with the ball-pushing lid protector is fitted to the core, but
In addition, as shown in FIG.
, (l J2 may be configured to spirally advance. In this case as well, when the ball pusher cover (21) comes into contact with the second steel ball group, the several ball pusher cover (21) is fixed by welding. This embodiment is similar to the above embodiment in that troublesome tuning using a tuning plate is not required.

゛ As mentioned above, the bicycle freewheel according to the present invention is different from the conventional method in which the screw cap is locked when the screw cap is tightened to the maximum, and the condition of the bearings must be adjusted to the optimum at the same time. The freewheel structure and assembly method that had been traditionally used since then was discarded, and the ball pusher lid was used as the second f for adjusting the bearing.
It is completed when it comes into contact with the IA ball group, and since the ball pusher lid is fixed by welding rather than screw means, it becomes possible to mass-produce products with a certain rotational performance using automatic machines. As a result, manufacturing costs are significantly reduced compared to conventional freewheels that had to be assembled one by one by manual adjustment using skilled techniques.

[Brief explanation of the drawing]

Claims (1)

[Scope of Claims] fl+ A core having a center hole with a thread for screwing onto the hub body, and a free gear (7) disposed in a mantle-like manner on the core, one, one pair! A pair of bearing structures constituted by a ball receiving surface formed between the core and the free gear so as to sandwich the group of balls and these steel balls, and a unidirectional rotational transmission (depending on the structure, the free gear [ti
lt bicycle freewheel, wherein an annular ball pusher lid having a ball receiving surface on the inner part is screwed or fitted and slid over the outer periphery of the outer cylindrical part of the core in the axial direction. The ball-receiving surface of the ball-receiving lid contacts a group of steel balls arranged in an annular manner on the ball-receiving surface of the inner peripheral surface of the 7-lead gear, and the ball-receiving lid moves on the cylindrical portion. A bicycle freewheel characterized in that the ball pusher lid is fixed by welding the contact portion between the ball pusher cap and the core when it becomes unable to move inward in the axial direction. (2) The welding according to claim 1, wherein the welding is performed by continuously or intermittently irradiating the contact portion between the core and the ball pusher lid with a laser beam focused to a small diameter. Freewheel for bicycles. (3) The bicycle freewheel according to claim 1, wherein the welding is performed by bringing thin-walled portions formed in advance on the core and the free gear into contact with each other and spot-welding them to each other. . (4) It has a core having a center hole in which a thread is carved for screwing into the hub body, and a free gear arranged in a manner that it fits into the core, and a pair of steel balls and these steel balls. A pair of bearing structures constituted by a ball receiving surface formed between the core and the free gear so as to sandwich the group of balls, and a one-way rotation transmission mechanism allow the free gear to rotate in only one direction with respect to the core. A method for assembling a bicycle freewheel configured to be freely supported, wherein a ring-shaped ball-pushing lid with a ball-receiving surface on the inside is placed over the outer periphery of the outer cylindrical part of the core. The ball-receiving surface of the core ball pusher lid contacts a group of steel balls arranged in an annular manner on the ball-receiver surface of the inner peripheral surface of the free gear, and the core ball pusher cap contacts the cylindrical portion. A method for assembling a bicycle freewheel, characterized in that when it is desired to move the top of the freewheel inward, the contact portion between the core and the core is welded. (5) The welding is performed by focusing a laser beam to a small diameter and continuously or intermittently irradiating the contact area between the core and the ball pusher lid with the laser beam. Assembly method described. (6) The assembly method according to claim 4, wherein the welding is performed by forming thin-walled portions in advance on the core and the free gear, and spot welding these thin-walled portions in contact with each other.