KR20120133684A - Dies and method for forming screw and screw manufactured by the method - Google Patents

Abstract

PURPOSE: A screw forming dies, screw forming method using the same and screw produced by the same are provided to process screws with an excellent quality as a portion of threads corresponding to a predetermined cutting line is cut after being dented by a pressing bite. CONSTITUTION: A screw forming dies comprises a pair of dies(10,20). Each die comprises a pair of screw forming units and cutting units. A material(1) is processed between the screw forming units, and screws are formed. The cutting units are formed at the lower part of the screw forming unit, and cut the end of the material. A pressing piece(15) is installed at the front side of the cutting unit in the direction for machining the screws. The pressing piece presses at least a portion of threads to be cut by the cutting unit.

Description

Die for screw forming, screw forming method using the same and screw manufactured by the same {Dies and method for forming screw and screw manufactured by the method}

TECHNICAL FIELD The present invention relates to a die for screw molding, a screw molding method, and a screw for molding a male screw or a bolt.

A thread forming die is a processing apparatus for inserting a material between a pair of dies and forming a male thread around the material.

Such thread forming dies may be classified into circular dies and square dies according to their shapes.

1 and 2 is a view of the prior art (Korean Patent 10-0973687) showing a square die, with reference to this will be described with respect to the thread forming die of the prior art.

The screw forming die as shown in FIG. 1 positions the thread forming material 71 between the fixed dice 50 and the movable dice 60 which are positioned to face each other, and moves the movable die relative to the fixed dice 50. It is configured to be able to machine the material by rolling the circumferential surface of the material 71 by relatively moving 60).

The stationary die 50 and the movable die 60 are provided with upper dies 52 and 62 having thread forming portions 52a and 62a, respectively, and the lower dies 51 and 61 are coupled to each lower portion. It consists of a configuration.

In addition, upper portions of the lower dice 51 and 61 are provided with cutting protrusions 51a and 61a formed in opposite directions to cut the lower portion 72 of the threaded material 71.

When the molding material 71 is supplied between the stationary dice 50 and the movable dice 60, the screw forming die moves the movable die 60 to one side, and moves the raw material through the thread forming parts 52a and 62a. The screw is formed on the outer circumferential surface of the 71 and then the cutting unit 51a and 61a are configured to cut the lower portion 72 of the screw to form the screw.

However, the screw forming die including the prior art as described above is to cut the lower portion 72 of the screw by both cutting protrusions (51a) (61a), as shown in Figure 2, but the thread forming portion (52a) (62a) Since cutting is performed in a state where a screw is already formed on the outer circumferential surface of the material 71 while passing through), more precise threading is not easy due to poor cutting.

That is, both cutting protrusions 51a and 61a cut the lower portion 72 where the screw is formed in the state where the thread is already formed before the lower portion 72 of the screw is cut. In this case, referring to FIG. When the blades and the threads 73 of the projections 51a and 61a come into contact with each other, a problem arises such that the sharp vertex and the vertex meet each other and are distorted, so that the cutting is not accurately performed at a desired position. There is a problem that limitation occurs in processing.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a die for screw forming, a screw forming method using the same, and a screw manufactured through the same, which enables more precise and excellent quality screw processing.

The screw forming dies according to the present invention for realizing the above-described problems are provided on a pair of screw forming portions which are formed on surfaces facing each other and which form a screw by processing a material therebetween, and a lower side of each screw forming portion. And a pair of dies including a pair of cutting portions for cooperating with each other and cutting the end portions of the raw material, and being cut by a cutting portion in front of at least one of the cutting portions in the threading direction of the die. Characterized in that the pressing portion for pressing at least a portion of the thread.

The pressing portion and the cutting portion are preferably arranged in order in the middle of the screw forming portion in the threading direction of the die.

It is preferable that the said pressing part consists of the inclined surface which protrudes gradually in the threading direction, and the planar part extended from this inclined surface to the front of the said cutting part.

Preferably, the pressing portion is formed such that the upper surface in contact with the screw forming portion is inclined in the thread forming direction.

The pair of dies may include a first screw bit formed with the thread forming part and a first block coupled to a bottom surface of the first screw bit to support the first screw bite, and the first screw bite and the first block. A first die including a push bite interposed therebetween and a first cutting bite interposed between the first screw byte and the first block at the rear of the push bite to constitute the cutting part; A second screw bite having a long length formed on the face of the first screw bite and a second screw bite coupled to a bottom surface of the second screw bite while being disposed to face the first block to support the second screw bite; It is preferably composed of a second die including a block and a second cutting byte sandwiched between the second screw byte and the second block to constitute the cutting portion.

In this case, it is preferable that a bite groove and a block groove are respectively formed on the surfaces of the first screw byte and the first block that face each other so that the push byte and the first cutting byte are inserted.

In addition, it is preferable that a bite groove and a block groove are respectively formed on the surfaces of the second screw byte and the second block facing each other so that the second cutting byte is inserted and positioned.

A screw forming method according to the present invention for realizing the above object comprises: a first step of forming a screw by processing a material between a pair of dies while moving at least one of a pair of dies; After the first step, pressing and recessing at least a portion of the thread to be cut prior to cutting the end of the material in the threading direction of the die; After the second step, characterized in that it comprises a third step of cutting the end of the material including the recessed in the second step.

At this time, it is preferable that the second step and the third step proceed while continuously forming a screw in the material between the pair of dies.

In addition, after the third step, it is preferable to continue to form a screw on the material for a certain period between the pair of die.

The screw which concerns on this invention for realizing said subject is produced and comprised by the screw shaping | molding method as mentioned above.

The main problem solving means of the present invention as described above, will be described in more detail and clearly through examples such as 'details for the implementation of the invention', or the accompanying 'drawings' to be described below, wherein In addition to the main problem solving means as described above, various problem solving means according to the present invention will be further presented and described.

Screw forming die according to the present invention and a screw forming method using the same, the cutting bite is provided with a pressing bite in front of the cutting bite, because a part of the thread of the cutting line to be cut after pressing down to cut the screw more precise and excellent quality Processing is effective.

1 is a perspective view showing a die for screw forming of the prior art,
Figure 2 is a cross-sectional view showing a screw forming state using the prior art screw forming dies, a view showing a process of cutting the lower portion of the material,
3 is a detailed view of the main part for explaining the problems of the prior art, including the prior art,
4 is a perspective view showing one embodiment of a screw forming die according to the present invention;
FIG. 5 is an exploded perspective view of the screw forming die illustrated in FIG. 4, in which both dies are disassembled in a laid down state;
FIG. 6 is a perspective view showing an arrangement state before screw forming using the screw forming die illustrated in FIG. 4; FIG.
7 is a side view of a first die side for showing a screw forming process using a screw forming die according to the present invention;
8 is an exploded view of a main component showing a screw forming process in a screw forming die according to the present invention.
9 to 11 are detailed views showing the screw forming process in order around the portion where the push bite is positioned in the present invention.

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

4 is a perspective view according to an embodiment of the present invention, FIG. 5 is an exploded perspective view of a pair of dies laid down from side to side, and FIG. 6 is a layout view when forming a screw.

With reference to these drawings, an embodiment of a screw forming die according to the present invention will be described.

The die for forming a screw is composed of a pair of dies 10 and 20, that is, a first die 10 and a second die 20, for rolling a screw on the material 1.

The first die 10 and the second die 20 are provided with a pair of screw forming portions 11a and 21a for machining the screws on the surfaces facing each other, and the screw forming portions 11a and 21a of the first die 10 and the second die 20 are provided. The lower side is provided with a pair of cutting portions 17 and 27 for cutting the end 3 of the screw while cooperating with each other.

In particular, at least one of the pair of cutting portions in the threading direction of the die is provided with a pressing portion 15 for pressing at least a portion of the thread to be cut by the cutting portion.

The screw forming parts 11a and 21a, the cutting part, and the pressing part may be provided in the screw bites 11 and 21, the cutting bites 17 and 27, and the pressing bite 15, which will be described below.

In the embodiment of the present invention described below, the pressing portion will be described based on the configuration provided only on one die, that is, the first die 10.

Now, the first die 10 and the second die 20 having the above configuration will be described in detail.

First, the first die 10 includes a first screw bite 11 having a long screw forming portion 11a formed on a surface (front surface) facing the second die 20, and a bottom surface of the first screw bite 11. A first block 13 coupled to and supporting the first screw byte 11, a push byte 15 interposed between the first screw byte 11 and the first block 13 to form the pressing part; It consists of a first cutting bite 17 which is sandwiched between the first screw bite 11 and the first block 13 at the rear of the push bite 15 to form the cutting part.

In this case, the bite groove 11b and the block groove may be inserted into the pressing thread 15 and the first cutting byte 17 on the surfaces of the first screw byte 11 and the first block 13 facing each other. 13b are formed and comprised, respectively.

The pressing bite 15 and the first cutting bite 17 are preferably arranged in order in the middle of the thread forming portion 11a in the threading direction of the die. That is, the first screw bite 11 is formed with a long screw forming portion (11a), the pressing bite 15 and the first cutting bite 17 in the middle of the lower portion of the portion formed with the screw forming portion (11a) in order It is configured to be arranged.

The push bite 15 is an inclined surface 15a which projects gradually forward from the front surface of the first block 13 in the threading direction and the flat portion 15b that extends from the inclined surface 15a to the front of the first cutting bite 17. It can be made of). Alternatively, the planar portion 15b may also be configured to be inclined to gradually protrude forward toward the first cutting bite 17. The inclination of the planar portion 15b is preferably configured to be lower than that of the inclined surface 15a.

In addition, the push bite 15 is preferably configured such that the upper surface (15c) in close contact with the first screw bite 11 is gradually lowered toward the rear side according to the screw forming direction of the screw forming portion (11a). That is, the upper surface 15c of the push bite 15 is formed to be gradually inclined along the thread forming portion (the valley portion of the screw forming portion) of the screw forming portion 11a.

The first cutting bite 17 has a first cutter 17a formed on its front surface in a screw forming direction. The first cutter 17a may be configured to gradually increase at an initial stage, and to form a plane having a constant height in subsequent sections.

Next, the second die 20 is disposed so as to face the first screw 13 and the second screw bite 21 having a long screw forming portion 21a formed on a surface facing the first screw bite 11. The second block 23 coupled to the bottom surface of the second screw bite 21 to support the second screw bite, and between the second screw bite 21 and the second block 23 to insert the cutting part. It consists of the 2nd cutting byte 27 which comprises.

In this case, the bite groove 21b and the block groove 23b may be formed so that the second cutting byte 27 may be inserted and positioned on the surfaces of the second screw byte 21 and the second block 23 facing each other. It is preferable to form each.

A second cutter 27a is formed on the front side of the second cutting bite 27 in the threading direction. Like the first cutter, the second cutter 27a may be configured to gradually increase at an initial stage to form a constant plane.

Meanwhile, in the above-described embodiment of the present invention, the configuration in which the push bite 15 is provided only on the first die 10 side is not limited thereto, and the first cutting in the thread forming direction may also be performed on the second die 20 side. It is possible to construct the push byte 15 in front of the byte 17.

In addition, in the above embodiment, the byte and blocks of the first die 10 and the second die 20 are divided and assembled to each other. Alternatively, only some components may be integrated. For example, the push byte 15 and the 1st cutting byte 17 can also be manufactured and comprised integrally.

A screw shaping method using an embodiment of a screw shaping die according to the present invention configured as described above will be described.

For reference, FIG. 7 is a side view of the first die 10 side to show the screw forming process, and FIG. 8 shows the pressing bite 15 and the cutting bite 17 after the material 1 is formed with the screw 2 '. ) Is a development diagram showing the process of going through the sequence.

6 to 8, an embodiment of a screw forming method will be described.

The material 1 to be formed with the screw may be processed by using a head portion and a circular body portion 2 extending from the head portion. In the drawings, reference numeral 3 denotes an end portion to be removed from the body portion.

The material 1 is a body part of the material 1 as the first die 10 and the second die 20 move relative to each other while being positioned between the first die 10 and the second die 20. The screw is rolled and formed in (2).

In this case, either one of the first die 10 and the second die 20 is fixed, and the pair of dies 10 and 20 are moved relative to each other in such a manner that the other die is linearly moved around the fixed die. In between, it is preferable to form a screw in the body portion 2.

6 and 7 show a process when the second die 20 is machined to the material 1 while the second die 20 moves from left to right in the drawing with the first die 10 fixed. In FIG. 7, the second die 20 is not illustrated for convenience.

When the material 1 enters the thread forming portion 11a of the first die 10 by the second die 20, the thread forming portions 11a of the first die 10 and the second die 20 are formed. 21a), a screw 2 'is formed around the body portion 2 of the raw material. At this time, the raw material 1 is processed as '1a' in FIG.

When the raw material 1a enters the portion where the push bite 15 of the first die 10 is positioned while the screw is formed around the body portion 2, the portion below the cut line is pressed in the body portion 2. While being pushed by the bite 15, a part of the screw thread is completely pressed and recessed, or it goes through a process of being recessed by a certain height. At this time, the material is processed as '1b'.

That is, as shown in FIG. 9, the upper surface 15c of the pressing bite 15 is positioned at the cutting schedule line just before the raw material 1 having the screw 2 ′ enters the inclined surface 15a of the pressing bite 15. It comes in contact with the screw thread 2a. At this time, the initial portion of the upper surface 15c is preferably positioned to contact the center of the thread 2a. Subsequently, when the raw material 1 passes through the inclined surface 15a of the push bite 15 as shown in FIG. 10, the thread 2a below the cutting schedule line is pressed down on the inclined surface 15a of the push bite 15 and starts to sink. Subsequently, when passing through the planar portion 15b of the push bite 15, the portion below the cutting schedule line (including the end portion 3 ') is recessed and a part of the thread is removed.

11 shows the state before the raw material is incorporated into the cutting bites 17 and 27 located after the push bite 15.

After the raw material 1 is out of the push bite 15, the cutter is cut by both cutters of the cutting bites 17 and 27 provided between the first die 10 and the second die 20. Cutting is made.

 At this time, the end 3 of the material 1 is cut and separated after passing through both cutters or after passing through both cutters. At this time, the material is processed as '1c' and '1d' of FIG. Reference numeral 3 'denotes a cut end.

Subsequently, the material from which the end portion 3 'is cut is continuously formed through the screw forming portions 11a and 21a of the first die 10 and the second die 20, and the screw is completely molded. The process of shaping the screw at 1 'is completed.

The screw formed by the above-described method is formed into a complete screw in which the screw 2 'has a constant diameter as a whole and the end portion 3 is flat.

On the other hand, in the above-described embodiment of the present invention has been described with respect to the square die, it is also applicable to the circular die for screw molding in the same or similar manner. In other words, the circular die may be provided with a pressing bite and a cutting bite between the screw forming parts or at the end of the screw forming part depending on the threading direction.

As described above, the technical ideas described in the embodiments of the present invention can be performed independently of each other, and can be implemented in combination with each other. While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art. It is possible. Accordingly, the technical scope of the present invention should be determined by the appended claims.

Claims (11)

A pair of thread-formed portions formed on mutually facing surfaces to form a screw by processing the material therebetween, and a pair of cutting portions provided at the lower side of each thread-shaped portion to cooperate with each other to cut the end portions of the material. Consists of a pair of dies,
And a pressing portion for pressing at least a portion of the thread to be cut by the cutting portion in front of at least one of the cutting portions in the threading direction of the die.
The method according to claim 1,
And the pressing portion and the cutting portion are arranged in order in the middle of the screw forming portion in the threading direction of the die.
The method according to claim 1,
And said pressing portion comprises an inclined surface which gradually protrudes in the threading direction and a flat portion extending from the inclined surface to the front of the cutting portion. The method according to claim 1,
The pressing portion is a thread forming die, characterized in that the upper surface in contact with the screw forming portion is formed inclined in the thread forming direction.
The method according to any one of claims 1 to 4,
The pair of dies may include a first screw bit formed with the thread forming part and a first block coupled to a bottom surface of the first screw bit to support the first screw bite, and between the first screw bite and the first block. A first die including a push bite inserted to constitute the pressing part, and a first cutting bit inserted between the first screw byte and the first block at the rear of the push byte to constitute the cutting part;
A second screw bite having a long length formed on the face of the first screw bite and a second screw bite coupled to a bottom surface of the second screw bite while being disposed to face the first block to support the second screw bite; And a second die including a block and a second cutting bite sandwiched between the second screw bite and the second block to constitute the cutting part.
The method of claim 5,
And a bite groove and a block groove are formed on the surfaces of the first screw bite and the first block that face each other so that the push bite and the first cutting bite are inserted.
The method of claim 5,
And a bite groove and a block groove are formed on surfaces of the second screw bite and the second block that face each other so that the second cutting bite is inserted therein.
A first step of forming a screw by processing a material between the pair of dies while moving at least one of the pair of dies;
After the first step, pressing and recessing at least a portion of the thread to be cut prior to cutting the end of the material in the threading direction of the die;
And after the second step, a third step of cutting the end of the material, including the portion recessed in the second step.
The method of claim 8,
The second and third steps are performed by continuously forming a screw in a workpiece between a pair of dies.
The method of claim 8,
And after the third step, a fourth step of continuously forming the screw in the material for a predetermined period between the pair of dies.
The screw produced by the screw shaping | molding method of any one of Claims 8-10.

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