JPS582710Y2 - Bicycle handle pull up bolt - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a hexagonal or hexagon socket pull-up bolt used in a bicycle handlebar.

This type of conventional bolt is made of steel material with a diameter of about 711 gl1 and has a threaded portion formed on the lower end body and a locking head provided at the upper end, but it has the following disadvantages.

First, the diameter of the threaded portion is 8 mm because the thread is formed by rolling means, and therefore the diameter of the bolt insertion hole provided in the handle is approximately 8.5 mm, compared to the diameter of 7 necks of the bolt. As a result, the inserted bolt is not properly fixed, and excessive force is likely to be applied to the base of the head due to looseness of the bolt, and this phenomenon is one of the causes of the head being missing.

Second, the locking head is formed by crushing the end of a steel material, and has a diameter of 711I! If a head with a thickness of 5.5 mm and a diameter of about 13 m is formed by crushing the end of the steel material Il in the axial direction, the steel material will inevitably weaken, so this will cause the head to be missing. Occur.

Since the head of the bolt as described above often falls off while the bicycle is being ridden, it is extremely dangerous for the user.

The present invention aims to provide a bicycle lifting bolt that can eliminate the above-mentioned disadvantages.

The proposed bolt will be explained below with reference to the attached drawings.
1 is a bolt body having a threaded portion 2 integrally formed at its lower end and a head 3 integrally formed at its upper end.

The threaded portion 2 of the bolt body 1 is made by rolling means, and therefore has a diameter d1 larger than the central body portion 4 of the bolt body 1.

The head 3 has a hexagonal hole 31 recessed in its upper surface, and an enlarged neck 5 that is continuous with the head 3 is integrally formed at its lower part. It is approximately the same size as the diameter d1.

The neck portion 5 is usually formed from an unprocessed part of a steel material used for making bolts, but in some cases it may be formed by processing a large diameter bar. For example, it may be formed by drawing a steel bar with a diameter of 9. You can make it.

On the other hand, the body 4 is made by elongating a steel material into a small diameter rod, using the method described below.

Further, the threaded portion 2 is rolled at the lower end of the elongated rod as described above, and due to this rolling, the diameter d1 becomes approximately equal to the diameter of the steel material, that is, the diameter d2 of the neck portion 5.

The head 3 is formed by crushing the upper portion of the neck 5, and is therefore formed by crushing the end portion of a steel material in the axial direction.

The diameter d1 of the threaded portion 2 is approximately 87ta according to the JIS standard, so if the neck portion 5 is made of unprocessed steel, a steel bar having a diameter of 87Igl may be used as the raw material for the bolt of the present invention. Further, the threaded portion 2 is a rolled thread, and the diameter of this thread is approximately 1 mm thick, so the diameter of the elongated rod, that is, the diameter d3 of the body portion 4 is approximately 7 mm.

Furthermore, since the diameter d4 of the neck 3 is usually 13M,
The end of a steel bar with a diameter of 871g1 will be expanded by 5M.

As described above, the method of manufacturing the bolt of the present invention differs depending on whether the neck portion 5 is formed from an unprocessed part of the material or by processing the material.

First, in the former case, as shown in Figure 3, the diameter is approximately .81 mm.
The first step A is to cut the steel material 1' of N1 to the required length, and then stretch this steel material by cold drawing to create the body portion 4 with a diameter of about 7M and the intended thread portion 2', as well as the neck portion 5. A second step B in which the corresponding portion of the head 3 remains, a third step C in which the corresponding portion of the head is crushed by cold upsetting, and the crushed head 3' is shaped and shaped. Using a method consisting of a fourth step (E) of finishing the head 3 with a hexagonal or hexagonal hole, and a final step (F) of threading the intended threaded portion 2' of this steel material 1' and subjecting it to heat treatment as required. Manufactured by

On the other hand, in the latter case, as shown in Fig. 4, the first step A is to cut a steel material 1' with a thick diameter, for example, a diameter of 911III, into the required length, and leave the head part 3' of this steel material. , and a second step B in which the other parts are stretched into a double bar portion 1a with a diameter of about 8 by cold drawing, and the head corresponding portion 3' of the steel material is crushed by cold upsetting, and by cold drawing. A third step C of extending the tip end side of the rod portion 1a by approximately half to form a portion 2' where the threaded portion is to be formed, and a portion corresponding to the neck portion 3'.
A fourth step is to form the neck part 3 with a hexagonal or hexagonal hole, and further stretch the remaining part of the rod part 1a by cold drawing to form the neck part 5. A manufacturing method is used which includes a final step F in which the intended portion 2' is threaded and, if necessary, heat treated.

In this method, the rod portion 1a is stretched in the fourth step, and as the neck portion 3 is crushed, the neck portion expands slightly, so the diameter of the neck portion 5′ is set smaller than the planned diameter. It is desirable to keep it.

According to an experiment, when a steel material 1' with a diameter of 911 m is stretched into a rod portion 1a with a diameter of 7.871a in the second step, the diameter of the neck corresponding portion 5' in the fourth step is 7.85 twins.
The diameter of the neck 5 completed in step E is z9wl~811g
It was 11.

In any of the above methods, the length l of the neck 5 is equal to the length l of the torso 4.
It is desired that the diameter be larger than about 771 gl1, preferably about 10 to 1511 gl1.

Since the pulling bolt of the present invention is as described above, when using it, the following effects can be expected.

Since the diameter of the neck portion 5 is approximately equal to that of the threaded portion 2, there is little looseness within the insertion hole of the handle, and the pulling bolt can be fixed well.

Since the head 3 is integrally continuous with the thick neck 5, the strength of this part is increased and accidents of falling off can be prevented.

Since a thicker steel material than the conventional one is used to make the neck part 5, there is less metal fatigue during the formation of the head part 3, and therefore it is possible to effectively prevent accidents of the head part 3 falling off due to deterioration in its material strength.

[Brief explanation of the drawing]

Figure 1 is a side view of the proposed bolt, Figure 2 is a top view of the same, and Figure 3 is a side view of the proposed bolt.
4 are schematic diagrams showing the manufacturing process of the bolt of the present invention. In the figure, 1 is a bolt body, 2 is a threaded portion, 3 is a head, 4 is a body, and 5 is a neck.

Claims (1)

[Scope of utility model registration request] 1. A threaded portion 2 is provided at the lower end of the bolt body by rolling means, and a head 3 is crushed and formed at the upper end, and between the head 3 and the threaded portion 2 is a body portion 4 having a smaller diameter than the threaded portion.
In the handle pull-up bolt, an enlarged neck part 5 that is continuous with the head part 3 is formed below the head part 3, and a diameter d2 of the neck part 5 and a diameter d1 of the threaded part 2 are formed.
A bicycle pull-up bolt configured so that the and are approximately equal. 2. The bicycle handlebar pull-up bolt according to claim 1, wherein the neck portion 5 is made of an unprocessed portion of steel material, and the body portion 4 is made by stretching steel material.