JPS5923665Y2 - Bicycle hanger shaft holding structure - Google Patents

Description

[Detailed explanation of the invention] 1. Purpose of the invention (1) Industrial application field of the invention, etc. The invention is directed to the bearing structure of a bicycle crankshaft, in particular, to a ball bearing that is screwed to both ends of the banger. This invention relates to a banger one that constitutes an outer lace and its dustproof device.

As mentioned above, the present invention is directly aimed at bicycle bangers and their dustproof devices, but it is an end cap for ordinary rolling bearings, which is screwed into the bearing casing and has a central hole in the end cap. A shaft passes through the end cap, and it can be used to seal the gap between the inner peripheral surface of the center hole of the end cap and the outer peripheral surface of the shaft with a sealing material such as rubber. Also, the effects described in the Effects section of this specification are produced.

(2) Prior art and its problems The basic structure of a bicycle crankshaft bearing is as shown in FIG. This is a forged product made by forging block material.

This banger one has a retaining part on its outer end surface that is engaged with a tool for rotating the banger one, and the banger one is rotated by this tool and screwed onto the inner threads at both ends of the banger 4, It is fixed by being prevented from turning by an appropriate means such as a lock nut or screw.

Of course, the gap between the inner peripheral surface of the center hole of this banger one and the outer peripheral surface of the crankshaft is
As shown in Japanese Patent No. 1413, it is sealed with a suitable dustproof cap.

There are demands to make bicycles lighter and to reduce the cost of manufacturing parts, and in order to meet these demands, it is conceivable to mold Banger One by applying press processing to steel plate material.

In this case, the banger one becomes a relatively thin cup-shaped member, so when forming the locking part for the rotating tool on the outer end surface, it is necessary to ensure sufficient depth and strength of the locking part. , it is necessary to make it not just a recess or a hole, but a notch (or hole, hereinafter the same) that reaches the inner surface of the hanger one.

Therefore, in addition to sealing the gap between the outer circumferential surface of the crankshaft and the inner circumferential surface of the center hole 5 of the hanger one, it is necessary to add some ingenuity to the structure of the dust-proof cap so that it can also seal the above-mentioned notch. occurs.

(3) Problems of the present invention The present invention provides the above-mentioned hanger one having a notch on its outer end surface that engages with a rotary tool, by connecting the outer peripheral surface of the crankshaft with a single removable sealing material. The object is to be able to seal the gap and notch between the center hole of the hanger one and the inner surface thereof.

2. Structure of the invention (1) Means taken to solve the problem The technical measures taken to solve the above problem are as follows.

(a) A notch is formed on the inner periphery of the end face of the thin hanger one, and (b) a dustproof cap made of an elastic material such as rubber is provided with a disc-shaped flange having a center hole and a cylindrical part in the center. (c) a ring-shaped protrusion is provided on the outer periphery of the tip of the cylindrical portion of the sealing material; (2) a seal lip is provided on the sealing material to protrude radially inward; (e) The cylindrical part is fitted into the center hole of the hanger one, and the inner peripheral part of the hanger one is held between the disc-shaped flange and the protrusion at the tip of the cylindrical part, and the sealing material is attached to the hanger one.

(2) Effect of the above means The cylindrical portion of the sealing material is tightly fitted into the center hole of the hanger one, and the annular projection at the tip thereof is locked to the inner surface of the inner peripheral portion of the hanger one.

At this time, since the cylindrical part has elasticity, the disc-shaped flange is pressed against the outer peripheral surface of the hanger one due to its elasticity, and the annular protrusion and the disc-shaped flange push the thin inner peripheral surface of the hanger one. Elastically pinches both the inner and outer sides of the

Therefore, the sealing material is firmly fixed to the inner peripheral part of the hanger one by the cylindrical part, the disc-shaped flange, and the annular projection at the tip of the cylindrical part.

In addition, in Hanger One, the distance between the inner circumferential surface of the center hole and the outer circumferential surface of the crankshaft is usually small, and the sealing material is , while holding the inner periphery of Hanger One,
This will secure it to Hanger One.

For this purpose, the radial direction between the tip of the seal lip of the sealing material that slides on the outer peripheral surface of the crankshaft and the part of the sealing material fixed to the hanger one, in other words, the part of the sealing material supported by the hanger one, is The gap between them is extremely small.

Furthermore, since the sliding contact of the seal lip with the crankshaft is so-called lip touch, the sliding resistance, in other words, the pulling force against the sealing material due to rotation of the crankshaft is small.

Therefore, the fixing force of the sealing material against the pulling force caused by the friction of the seal lip with the crankshaft only needs to be extremely small. It can withstand the pull of the material due to the rotation of the crankshaft.

In addition, the disc-shaped flange extends radially outward along the outer surface of the hanger one, and is pressed against the inner circumference of the hanger one, so that it covers the notch formed in the inner circumference of the hanger one. Seal this.

When the sealing material attached and fixed to Hanger One is pulled outward on its disc-shaped flange, the annular protrusion of the cylindrical part is elastically deformed and comes off from the inner surface of Hanger One, and the cylindrical part comes out of Hanger One. .

Therefore, the sealing material is easily removed from the hanger one.

When the sealing material is removed, a notch in the hanger one is exposed, and a rotary tool can be engaged with this notch.

Since the sealing material is elastically deformed and removed, it is not damaged by the removal operation and can be reattached to the hanger one.

In addition, from the viewpoint of ease of mounting the sealing material, reliability, and strengthening of the gripping force, it is desirable that the annular projection is a complete ring-shaped projection. In solving the problem, there is no problem even if the annular protrusion is a partially missing annular protrusion.

3. Effects of the invention (1) Unique effects produced by the invention A banger one in which a dustproof cap is directly attached to the inner circumference is shown in Japanese Utility Model Publication No. 3015/1983.

Because this banger one is not formed by pressing a steel plate material, the end of the banger one is thick, and a hole for engaging a rotating tool is formed on the outer surface of the banger one. It has the necessary wall thickness.

Therefore, although this lacks the premise of the present invention, if this banger one is made thin, the illustrated hole in which the rotary tool engages will be a hole that penetrates to the inner surface of the banger one.

In this case, the flange portion of the backing 11 can be enlarged radially outward, thereby covering the hole.

This can be easily understood by those skilled in the art based on their knowledge, and can be said to belong to the latent state of the art.

By doing so as well, the above-mentioned technical problems of the present invention can be solved to a certain extent.

However, when doing this, the engagement hole with the rotary tool must be located on the outer periphery of the banger one, and the backing 11 must be annular grooves 7, 7' having sloped surfaces 6, 6' on the outer surface of the banger one. Because of the fact that the backing 11 is fitted with cannot be adequately sealed.

In contrast, in the present invention, the annular flange is attracted to the outer surface of the banger one and pressed against the inner periphery of the banger one due to the elasticity of the cylindrical portion of the sealing material. It can cover gaps tightly.

Furthermore, it is shown in the cited example above.

The mechanism for attaching the backing 11 to the banger one is a structure in which the backing is fitted into an annular groove on the outer surface of the banger one to identify the backing.
(Specifically, cap 8) is required, and the wearing of Patsukin,
In order to remove the retainer, it is necessary to put on and take it off.

On the other hand, in the dustproof cap of the present invention, the cylindrical part of the sealing material is fitted into the center hole of the banger one and fixed by its own elasticity, so there is no need for a special glue retainer, and the sealing material By pushing the cylindrical portion into the center hole of the banger one, the annular projection at the tip immediately engages with the inner surface of the inner peripheral portion of the banger cover.

Therefore, it is easy to install and remove.

This advantage also applies to the mounting mechanism known as the mounting mechanism for the dustproof cover of Banger One, such as those shown in Japanese Utility Model Publication No. 33-4015 and Japanese Utility Model Publication No. 30-1413. Another major advantage of the present invention is that there is no need to perform any special processing on the banger one in order to attach the dustproof cover directly to the banger one.

3. Example Hereinafter, an example will be described as a specific example of the measures taken to solve the problem of the present invention.

The left and right banger ones 3a and 3b are made of steel plates that are drawn by press forming and have a wall thickness of 2.3 mm to 3.2 mm.
Finish into a nano-sized one-shape.

The wall thickness in this case is appropriately selected in consideration of the size of the outer diameter of the banger one and the depth of the male thread 7a formed on the outer periphery.

Although it is preferable to be thin from the viewpoints of ease of molding, material saving, and weight reduction, it is desirable to have a certain degree of wall thickness from the viewpoint of the rigidity of the banger one and the retention of the sealing material by the banger one.

Taking these points into consideration comprehensively, the length may be appropriately selected within the range of 2.3 mm to 3.2 mm in the specific design.

Regarding the axial length of the banger one, there is no difference from the conventional banger one, and the outer periphery is threaded, and one banger one 3a is provided with an annular protrusion 8 that is not threaded. There is no difference from the conventional banger one.

In the inner periphery of the banger ones 3a, 3b of this embodiment, notches 9a, 9b are provided facing each other.

The width in the circumferential direction and the length in the radial direction of this notch may be large enough to engage with a claw of a tool for rotating the banger one, and preferably as small as possible.

For example, the width may be 3 mm and the radial length may be 2 mm.

The reason why this notch is a so-called notch that opens inward in the radial direction is convenient because it allows the notch to be formed at the same time when punching out the steel plate and removing material. This is because this shape is convenient for engagement with the notch.

If these considerations are not taken into account, a simple cutout with a hole may be sufficient.

The sealing material installed on Banger One 3a and 3b is
It is made of a so-called rubber material such as polypropylene, polyethylene, synthetic rubber, etc., and the shape of the disc-shaped flange 10 is as follows.
It is necessary to have a shape that matches the shape of the bottom of the banger one 3a, 3b, and its outer diameter should be large enough to completely cover the notches 9a, 9b of the banger one, but the diameter should not be too large. There's no need.

The radius is 1 to 2 times larger than the diameter of the outer circumference of the notches 9a and 9b.
It is sufficient to have a large diameter of mm.

The thickness of the flange 10 should be such that it has enough rigidity to grip the inner circumference of the sealing material and enough elasticity to press the outer surface of the bottom of the sealing material and seal the notch. Thickness that can be achieved, e.g. 0.5mm to 0.7m
m is fine.

The inner diameter of the cylindrical portion 12 protruding in the axial direction from the center of the flange 10 is larger than the outer diameter of the crankshaft 2 (usually 15.88 mm) by the radial height of the seal lip 15, and the outer diameter When the cylindrical part is made slightly larger than the inner diameter (for example, 18 mm) of the hole 15 of the banger one and is press-fitted into the hole 5 of the banger one, the cylindrical part 12 is elastically deformed inward in the radial direction, and its elasticity is The outer periphery of the cylindrical portion 12 is brought into pressure contact with the inner surface of the hole 5.

Thickness of the cylindrical portion 12, annular projection 1 protruding from the tip of the cylindrical portion
The axial width and radial height of 3 are each 005 mm ~
The distance between the flange 10 and the annular protrusion 13 may be 1 mm, and the distance between the flange 10 and the annular projection 13 is made slightly smaller (for example, 0.2 mm) than the wall thickness of the inner diameter part of the bottom of the banger one, and the cylindrical part 12 is fitted into the hole of the banger one. Due to the elasticity due to the elongation of the cylindrical part,
The inner and outer peripheral parts of the bottom of the banger one are elastically gripped by the flange 10 and the annular projection 13.

Each dimension of the sealing material may be appropriately selected in consideration of the type of material and the efficiency and effectiveness of vulcanization molding.

In the illustrated example, the sealing lip 15 is attached to the flange 1
It protrudes from the inner circumference of 0.

When provided protrudingly on the inner periphery of the annular protrusion 13, the seal lip has a reinforcing effect on the annular protrusion 13, and the gripping force of the annular protrusion on the /'% ring is strengthened.

If the lip is provided protruding from the inner circumference of the disc-shaped flange, there is less possibility of damaging the seal lip when attaching or removing the seal material.

On the other hand, since the seal lip is exposed to the outside of the container, there is a possibility that it may become contaminated.

The position of the seal lip, whether one seal lip or two seal lips should be provided, should be selected as appropriate, taking into consideration the above points.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional example, Fig. 2 is a sectional view of an embodiment of the present invention, Fig. 3 is a front view of the engine shown in Fig. 2, and Fig. 4 is a view of the dustproof cap shown in Fig. 2. It is a cross-sectional perspective view. 2...Crankshaft, 3a, 3b...Nonger one, 4...Banger, 9 a, 9
b... Notch, 10... Disc-shaped flange, 11... Seal material, 12... Cylindrical portion, 13... Annular Protrusion, 15...
seal lip.

Claims (1)

[Scope of utility model registration request] In a bicycle banger, a notch is formed in the inner periphery of the end face of a thin banger one, and a dustproof cap made of an elastic material such as rubber is attached to a sealing material having a disc-shaped flange with a center hole and a cylindrical part in the center. A ring-shaped protrusion is provided on the outer periphery of the tip of the cylindrical portion of the sealing material, a seal lip is provided on the sealing material to protrude radially inward, and the cylindrical portion of the sealing material is fitted into the center hole of the banger one. A dustproof device for a bearing part of a bicycle crankshaft, in which the disc-shaped flange and the protrusion at the tip of the cylindrical part sandwich the inner peripheral part of the banger one, and a sealing material is attached to the banger one.