JPS63212018A - Manufacture of plain washer - Google Patents

Abstract

PURPOSE:To manufacture a plane washer at a good yield by winding a slender plate material made through rolling an annealed wire rod in the direction that its width direction is to be a radial direction and allowing to approximate the cut surfaces of a cut coil spring relatively and heat treating. CONSTITUTION:The slender material 1A made by rolling the annealed wire rod is wound spirally on a pipe P having a prescribed diameter in the direction that the width direction of the plate material 1A is to be radial direction. Cutting every one round successively by a cutter 3, a coil spring 4 is made. Then, it is pressed to form the plain washer 6 and hardened to improve both strength and rigidity. Therefore, the plain washer 6 is manufactured at a good yield and its cost is drastically reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a flat washer used particularly for high tension bolts.

[Conventional technology]

Flat washers for high-tension bolts are made with a thick plate to increase strength and rigidity, but flat washers, including energized washers, are generally manufactured by punching a steel plate using a press, etc. .

[Problem that the invention seeks to solve]

However, according to the above-mentioned conventional method for manufacturing flat washers by punching, the yield (material utilization rate) for raw steel sheets is extremely low at less than 50% due to the ring-shaped washer shape, and the yield worsens especially for larger washers. There was a tendency to As a result, raw materials were wasted, making it impossible to reduce manufacturing costs, which became a major factor in increasing the unit price of the product.

The present invention was developed to solve the above-mentioned problems, and aims to significantly improve the yield and significantly reduce the cost of the product by abolishing the punching process using steel plates.

[Means for solving problems]

As a specific means to solve the above problems, after annealing the mild steel wire rod is rolled and formed into Ill and IjL plates, this is wound spirally so that the width direction of the plate is the radial direction. , and then cut each turn to form a -wound coil spring shape, and then pressed until both cut surfaces come close to each other to form a ring shape, and then heat-treated. This is a manufacturing method.

[Effect]

According to the method for manufacturing a flat washer as described above, a linear raw material is rolled and formed into a plate shape, and this is! Since it is a spiral winding method, if you want to change the dimensions of the flat washer, you only need to change the diameter of the mild steel wire. Therefore, the yield does not change depending on the size of the washer being manufactured, and there is no wastage of raw materials. It becomes possible to manufacture a low-cost flat washer by omitting the above.

[Example] An example of the present invention will be described below based on the drawings. 1st
Figures (A) to (F) sequentially illustrate the steps involved in manufacturing a flat washer for high-tension bolts, and similarly, FIG. 2 shows the steps in a flow diagram.

First, as shown in FIG. 1(A), an annealed mild steel wire rod 1 is cold-rolled by rolling rollers 2A and 2B, and processed into an elongated plate material LA as shown in FIG. 1(B). Note that this rolling may be done by hot rolling, and in this case, it is not necessary to anneal the wire rod 1. Further, the diameter dimension of the mild steel wire l and the thickness of the plate material LA are set in advance according to the size of the flat washer to be manufactured, that is, the standard.

Next, the rolled plate material IA is spirally wound around a pipe P of a predetermined diameter with the width direction of the plate material IA as the radial direction, as shown in Figure (C), and then cut one by one with a cutter 3. Then, it is formed into the shape of a negative-wound coil spring 4 as shown in FIG. Next, as shown in figure (E), press 5.
When both cut surfaces 4A and 4B are pressed until they face each other, it is possible to manufacture a ring-shaped flat one-shape 6 in which the cut surfaces are in close contact with each other as shown in FIG. The flat washer 6 at this point is soft because the material is annealed, and therefore, it is finally hardened to increase its strength and rigidity. Furthermore, after quenching, antirust treatment such as plating is applied as necessary before use.

According to the manufacturing method described above, the yield can be improved to about 98% and the material utilization rate can be extremely high.

In addition, since the flat washer after quenching has sufficient strength and rigidity, there is no risk of it expanding when bolts are fastened even if there is a cut, but depending on the application, the cut part may be fixed by welding etc. Strength and rigidity can also be increased.

Incidentally, in the above manufacturing process, the -shaped coil spring 4 (see figure n) cut by the cutter 3 can also be used as a spring washer by being hardened.

〔Effect of the invention〕

As explained above, according to the flat washer manufacturing method of the present invention, the yield is significantly improved compared to the conventional manufacturing method using punching, and raw material usage efficiency is increased, reducing waste and making it possible to save resources. becomes. Furthermore, there is an effect that product costs can be significantly reduced due to material cost savings.

[Brief explanation of the drawing]

FIGS. 1A to 1F are process diagrams showing the method for manufacturing a flat washer of the present invention, and FIG. 2 is a flowchart of the same. ■...Mild steel wire rod IA...Plate material 2A, 2B.
...Roller 3...Cutter 4...Coil spring
4A, 4B...Cut surface 6...Flat washer patent applicant Toyo Spring Industry Co., Ltd. Figure 2

Claims (1)

[Claims] After rolling the annealed mild steel wire and forming it into a long and thin plate,
This is wound spirally so that the width direction of the plate material is the radial direction, and then cut each turn to form a single coil spring shape, and then press until both cut surfaces face each other and come close to each other. A method for manufacturing a flat washer, characterized by forming it into a ring shape and then subjecting it to heat treatment.