JPH0455032A - Production of headless set screw - Google Patents

Abstract

PURPOSE:To obtain the product which is beautiful in finish and has excellent quality by producing the headless slit screw by using an ordinary header, slitting machine and thread rolling machine. CONSTITUTION:A round bar-shaped screw blank material 1 is formed by cutting a metallic wire to a prescribed length and is forged by an ordinary header, by which a blank 1a having a recessed part 2 concentrical with the axial center and a collared head part 3 at one end is formed. Screw threads 4 are then rolled by as much as the length corresponding to the depth of the slit groove 5 to be described later to the part under the neck of the collared head part 3 by using thread rolling dies 11, 11. The slit groove 5 of the prescribed depth extending from the center of the collared head part 3 in the axial direction is cut by the ordinary slitting machine. The screw threads 4 are rolled over the entire length of the blank 1a by the thread rolling dies 12, 12 and the collard head part 3 is lifted and is cut by press cutting dies 13, 13 on the thread rolling dies 12, 12 so as to be press cut along the peripheral edge 6a at the base 6 of the recessed part 2 simultaneously with the above-mentioned rolling. The headless slit set screw 7 is thus completed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a headless slotted set screw and a method for manufacturing a hexagon socket set screw.

Conventional Technology Traditionally, slotted setscrews were manufactured by cutting on automatic lathes. Although this method has high processing accuracy,
There were problems in that productivity was low, the manufacturing process was complex and required skill, and costs were high. Furthermore, manufacturing equipment was also expensive.

On the other hand, hexagon socket set screws can be manufactured using an automatic lathe in the same way as the slotted set screws described above, or after forming a blank with a hexagon socket using a header or nut former, the screws are screwed using a rolling machine. A method of rolling the mountain is used.

The former method has the same problems as the above-mentioned method for manufacturing slotted setscrews, and the latter method requires a supply device such as a parts feeder in the secondary thread rolling process because the blank does not have a head after the primary processing. Not only was this necessary, but there was a risk that the hexagonal hole would be crushed and deformed.

Problems to be Solved by the Invention The present invention solves the problems of the conventional manufacturing method described above.
It is an object of the present invention to provide a method for manufacturing headless set screws that can be used to mass-produce headless slotted set screws and hexagon socket set screws with high precision and at low cost.

Means for Solving the Problems In order to achieve the above object, in the method for manufacturing a set screw with a slot according to the present invention, a recess concentric with the axis and a flanged head are formed at one end of a round bar material of a predetermined length. After forming a blank having a shape and rolling a thread of a length corresponding to the width of the slot under the neck of the flanged head, a thread having a constant depth extending in the axial direction from the flanged head is formed. Process the slot of the
Thereafter, the thread is rolled over the entire length of the blank, and at the same time, the flanged head is lifted and cut along the periphery of the bottom surface of the recess.

In addition, in the method for manufacturing a set screw with a hexagonal socket, a blank having a recess concentric with the axis, a hexagonal hole and a flanged head extending in the axial direction from the bottom of the recess is placed at one end of a round bar material of a predetermined length. The method is characterized in that, at the same time as forming and rolling a thread over the entire length of the blank, the flanged head is lifted and cut along the bottom periphery of the recess.

Function: In the method of the present invention, the threads are rolled while the blank has a flanged head at one end, so it can be continuously processed using a normal rolling machine (thread rolling machine), and the thread rolling process is possible. At the same time as processing, the brim-like head is lifted and cut along the periphery of the bottom surface of the recess, resulting in a beautiful finish.

In the case of a set screw with a slot, a thread is rolled under the neck of the flanged head with a length corresponding to the depth of the slot, and then the thread extends in the axial direction from the flanged head. Since the slots are formed with a constant depth, when rolling the threads over the entire length of the blank, no great force is applied to the locations where the slots are provided. Therefore, there is no risk that the full surface of the slot will be deformed.

On the other hand, in the case of a hexagon socket set screw, the threads are rolled while having a flange-like head as described above.
The hexagonal hole previously provided in the blank will not be crushed and deformed.

Example Embodiments of the present invention will be described below based on the drawings.

1 to 5 show the manufacturing process of a slotted set screw according to the method of the present invention.

A metal wire is cut to a predetermined length to form a round bar-shaped bracing material 1, and the material 1 is pressed and formed using a normal header (not shown), and as shown in FIG. Recess 2
A blank 1a having a brim-shaped head 3 is formed.

Next, as shown in FIG. 3, the preliminary rolling die 11.11
After rolling a thread 4 with an axial length corresponding to the depth of the slot groove 5 (described later) under the neck of the flanged head 3 of the blank 1a using A slotted groove 5 of a constant depth extending in the axial direction from the center of the flanged head 3 is cut (see FIG. 4).

After that, as shown in FIG. 5, the thread rolling die 12.
12, the thread thread 4 is rolled over the entire length of the blank 1a, and at the same time, the flanged head 3 is lifted and the concave portion 2 is rolled by the push-cutting die 13.13 superimposed on the thread rolling die 12.12. The headless slotted set screw 7 is completed by cutting along the peripheral edge 6a of the bottom surface 6. 10 indicates the scrap that has been cut and removed.

6 to 9 show the manufacturing process of a hexagon socket set screw according to the method of the present invention.

A metal wire material is cut to a predetermined length to form a round bar-shaped wire material 1, and the material 1 is pressed and formed using a normal header (not shown) to form a concave portion 2 concentric with the axis and a flange-shaped head at one end. 3 and further has a hexagonal hole 8 extending in the axial direction from the bottom surface 6 of the recess 2.

Thereafter, as shown in FIG. 8, the thread rolling die 14.
14, the thread 4 is rolled over the entire length of the blank 1b, and at the same time, as shown in FIG. , the headless hexagon socket set screw 9 is completed.

As described in detail, according to the method of the present invention, a slotted set screw and a hexagon socket set screw are manufactured using a normal header and slotting machine and a normal rolling machine (thread rolling machine). and can be provided at low cost.

Moreover, the finish is beautiful and the quality is excellent, comparable to machined products.

[Brief explanation of the drawing]

1 to 5 are process explanatory diagrams showing the manufacturing process of a set screw with a slot according to the method of the present invention, and Figures 6 to 9 are process diagrams showing the process of manufacturing a set screw with a hexagonal socket according to the method of the present invention. It is an explanatory diagram. 1...Screw material 1a, lb...Blank 2
-... Recess 3... Flange-shaped head 4... Thread 5... Slotted groove 6... Bottom of recess 2 6a... Periphery of bottom 6 7... Slotted stopper 8...Hexagon socket 9...Hexagon socket set screw 10...Scrap

Claims (2)

[Claims] (1) A blank having a concave portion concentric with the axis and a flanged head is formed at one end of a round bar material of a predetermined length, and a length corresponding to the depth of the slot is formed under the neck of the flanged head. After rolling the threads, a slot of a certain depth extending in the axial direction from the flanged head is machined, and then the threads are rolled over the entire length of the blank, and at the same time, A method for manufacturing a headless slotted set screw, characterized in that the brim-shaped head is lifted and cut along the bottom periphery of the recess. (2) A blank having a concave portion concentric with the axis, a hexagonal hole extending in the axial direction from the bottom of the concave portion, and a flanged head is formed on one end of a round bar material of a predetermined length, and a blank is formed over the entire length of the blank. A method for manufacturing a headless hexagonal socket set screw, characterized in that the thread is rolled using a screw thread, and at the same time, the flanged head is lifted and cut along the bottom periphery of the recess.