JPS5919777B2 - Bicycle seat/lug manufacturing method with reinforcing beads - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a seat rack located directly below the saddle of a bicycle, particularly a seat rack having reinforcing beads near the ear pin fastening portion of the seat rack, by a continuous pressing method. It is related to the method of manufacturing.

A person riding a bicycle, that is, a rider, has his or her upper body supported by a saddle, and the position of this saddle can be adjusted according to the rider's height.The present invention provides a component for adjusting the vertical position of the saddle. A seat rack is provided.

A seat pillar (also referred to as a seat post) is directly fixed to the saddle, and this seat pillar is inserted into the vertical pipe of the bicycle assembly pipe body through a seat rack, and is inserted into the above-mentioned ear shape of the seat rack. It is designed to be stopped and fixed at an appropriate position on the seat pillar by a pin tightening part. Although the seat rack itself is a small part that can be held in the palm of a person's hand, the conventional manufacturing method involves manufacturing it from steel sheets in several steps including welding, casting, and forging, which is extremely inefficient. I had to say it was amazing. According to the present invention, a series of metal forming press lines enables high-speed and highly efficient production, which is much faster than conventional manufacturing methods, specifically in just 3 seconds per seat rack. Therefore, it has become possible to significantly reduce production costs.

Conventionally, when using a seat rack, a packing-like device called a nest was inserted at the same time, and a bolt with a nut was inserted through the ear-shaped pin tightening part, and by using this bolt, the so-called nest We worked with them to tighten the seat pillar and secure it to the vertical pipe.

Since the seat rack is used as described above, the tightening and fixing is performed only by the frictional force between the seat and pillar and the vertical pipe, so the tightening and fixing may occur depending on the situation. There may be some relaxation.

Such accidents must be avoided at all costs.
In order to prevent such unexpected accidents and to maintain the elasticity and strength of the pin tightening part over a long period of time, in the present invention, a reinforcing bead is installed near the pin tightening part.

The steel plate used in the present invention is a cold rolled steel specified by JIS G3l4l high grade finishing steel plate type 3 SPCE, and is made into a continuous steel strip.

According to this standard, CO. O8% or less, MnO. 40% or less, PO. O3O% or less, SO. O3O% or less, balance F
It has a tensile strength of 28 kg/〒 or more and an elongation of 42 or more. Steel strip size is thickness 2111 width 1301
1 and continuously fed to a metal forming press.

One metal forming press is prepared for each process of the present invention, and a transfer/feed is installed.
Continuously produced as a press line, approximately 3 pieces per piece.
It can be produced in seconds. The manufacturing method of the present invention will be described below with reference to the accompanying drawings.

The drawings include sketch views and corresponding cutaway views in order to facilitate understanding of the present invention. FIG. 1 shows the first aperture, FIG. 3 shows the second aperture, and FIG. There is. In the present invention, the steel plate material 1a
The required cylindrical protrusions 2a, 2b are drawn by a metal forming press using a mold consisting of a pair of upper and lower parts.
, 2c, the procedure is as taught in general press technology books, and by calculating backwards from the cylindrical protrusion required in the final product, the first drawing should be about 60% or less. The drawing process is performed at a drawing rate of about 85% in the second drawing and about 88% in the third drawing. This will be described specifically as follows.

In this case, a word about work hardening caused by drawing is that in the present invention, annealing is not performed in each step, and if processing is performed by loosening the degree of hardening, that is, the drawing rate, in each step as described above, The drawing process could be carried out without destroying the material during the process. It is also believed that this is partly due to the fact that high-grade steel as mentioned above was used as the material. In the fourth step of drilling shown in FIG. 7, a rough circular hole 4 is bored at the upper end of the cylindrical projection, and in the fifth step shown in FIG. Fold both left and right sides (representatively, only 1f is shown) as the 11th
In the sixth step shown in the figure, the rough circular hole 4 is burred and at the same time an adjustment process is performed so that the cylindrical protrusion 2f has a predetermined angle as a completed seat rack product.

In the seventh step of trimming shown in FIG. 13, the peripheral scrap portion 3 is cut and removed so as to have a desired shape. In the eighth step shown in FIG. 15, both ear portions 5a and 5b are squeezed out at predetermined locations on both left and right side portions.

These ears 5a, 5b are portions that become ear-shaped pin fastening portions of the seat rack, and pin insertion holes 8a, 8b (see FIG. 17) are formed in both ears 5a, 5b. Furthermore, in the eighth step, the reinforcing bead 6, which is a feature of the present invention, is
Squeeze out a and 6b at the same time. The reinforcing beads 6a, 6b are provided near both ears 5a, 5b, and are provided here because the parts of both ears 5a, 5b are tightly tightened with pins, ie, bolts, etc., as described above. Due to fatigue of the metal, it loses its elasticity, and there is insufficient force to tighten and fix it to the seat pillar, making it impossible to maintain a fixed position, which may cause an unexpected accident. In the present invention, in order to prevent such accidents, it has been decided to provide reinforcing beads 6a, 6b near both ear portions 5a, 5b.

Fig. 15 shows an arch-like shape of the reinforcing beads 6a, 6b, and the width of the bead is approximately 2mT1L1.
The length is approximately 14-15u in total, and instead of an arch shape, the arc part is omitted and the length is 7m1 with a straight bead.
Two pieces may be installed in parallel.

The convex surface of the bead is made so that it protrudes from the back side of the material to the front side. Next, although the ninth step is omitted in the drawings, the ninth step is a notch step, and this notch step is also proposed for the first time in the present invention.

As shown in FIG. 23, this notch is made by cutting out concave-convex engaging portions 9 at both connecting ends of both side portions. When the cutout portions 9 become uneven and engage with each other,
Both connecting ends are fixed.

Generally, the seat rack is supplied as a single unit by the manufacturer to the car body assembler, and the assembler first cuts the connection points of the ear pin fastening portions of the seat rack when assembling the pipe frame. The conventional seat rack is the 24th
As shown in the figure, the connection points were welded 10 before shipment.
According to the present invention, the welding process can be omitted and replaced by a concave-convex engagement piece, making it possible to reduce the unit price of the seat rack.

The 10th step shown in FIG. 17 is the second bending process,
The eleventh step shown in FIG. 19 is a final bending step and engagement of the concavo-convex interlocking portions to obtain a desired finished molded product.

Arrow A shown in FIG. 21 indicates that a seat pillar (not shown) is inserted from the direction shown in A and passes in the direction of arrow B, and the same is shown in FIG. 23.

In order to obtain the above-mentioned tightened and fixed state, the seat racks of the conventional and the present invention have a weight of 2 kg-2 with or without nests.
Tighten each with a torque of m, and about 100 kg on the saddle.
After about 10 hours had elapsed since a stationary body weighing 100 lbs. had been placed on the seat rack, the state of tightening and fixation of each seat rack was observed, and the above-mentioned scores were obtained.

The results show that the seat rack with reinforcing beads of the present invention achieved equally good results regardless of the presence or absence of nests. Although the present invention resides in the features described in the claims, it can be implemented in the following points according to the present specification.

(1) In the method described in the claims, the reinforcing bead in the eighth step is arch-shaped.

(2) In the method described in the claims, the reinforcing beads in the eighth step are two straight lines. (3) In the method described in the claims, in the ninth step, both connecting ends of the both side portions are welded.

[Brief explanation of the drawing]

The drawings show the method of the present invention, and include Figures 1-2 and 3-4.
5-6 show the first aperture, second aperture, and third aperture, respectively, and FIGS. 7-8, 9-10, and 11-12 show the subsequent steps, and Figures 13-14 show the trimming process, Figures 15-16 show the reinforcing bead and both ear parts squeezed out, Figures 17-18 and 19-20 show the subsequent process, and Figure 21 shows the steps from A to A. FIG. 22 is a perspective view taken in the direction B, FIG. 22 is a front view seen from the direction A in FIG. 21, FIG. 23 shows an uneven meshing portion, and FIG. 24 shows a welding location. 1a, 1b, 1c, 1d, 1e, 1f... Steel plate material, 2a, 2b, 2c, 2d, 2e, 2f...
・Cylindrical protrusion, 3... Scrap part, 4.
...Opening hole, 5a, 5b...Both ear parts,
6a, 6b... Reinforcement beads, 7a, 7b...
...Both sides, 8a, 8b...Both ear holes.

Claims (1)

[Claims] 1 A press line consisting of several metal forming press machines is made of high-quality finished steel strip with a thickness of approximately 2 mm and a width of approximately 130 mm according to JIS regulations, and a mold consisting of a pair of upper and lower molding machines is used for each of the following processes. In the first drawing process, the cylindrical protrusion is estimated from the final required forming cylindrical protrusion, and the cylindrical protrusion is squeezed out with a reduction rate of about 60%, and in the second process, the cylindrical protrusion is further reduced to about 85%. A second drawing is performed at a drawing rate of about 88%, and a third drawing is carried out again at a drawing rate of about 88% in the third drawing process, and the upper end of the cylindrical protrusion is finally formed in the fourth process of drilling. Drill a rough circular hole, bend both left and right sides around the cylindrical protrusion in the first bending process of the fifth step, and give a predetermined angle to the rough circular hole at the same time as burring process in the sixth step. Processing is performed, peripheral scrap parts are removed from the material so as to obtain the desired shape in the trimming process in the seventh step, and both ear parts and reinforcing beads are squeezed out at predetermined locations on both the left and right sides in the eighth process. A predetermined hole is drilled in both ears, and in the ninth step notch processing, an uneven interlocking portion is cut out at both connecting ends of the both side portions, and a second bending step is performed in the tenth step. A method for manufacturing a seat/lug with reinforcing beads for a bicycle, characterized in that in the eleventh step, the uneven interlocking portions are engaged to complete a desired molded product.