KR101808320B1 - L-bolt and its manufacturing method and manufacturing apparatus - Google Patents

Abstract

The present invention provides an L-bolt, manufactured through only a forming process without a trimming process, so as to remove a problem of breakage of an eccentric head part of the L-bolt broken in use, and provide effects of reducing material costs and enhancing productivity; and a manufacturing apparatus and a manufacturing method thereof. According to the present invention, the method comprises: a first process (#1) of using a former and a cut material (10) to form a first preformed eccentric head part (11) of an L-bolt through a cold forging process using a first dice (14-1) and a first sliding punch (15-1) when the material (10) is restricted; a second process (#2) of using the head part (11) first performed in the first process (#1) to form a second preformed head part (11) through a cold forging process using a second dice (14-2) and a second punch (15-2) when the material (10) is restricted; a third process (#3) of forming the second preformed head part (11) into a third preformed head part (11) through a cold forging process, and using a third dice (14-3) and a third punch (15-3) to extrude the third preformed head part (11) in order to form a step between a body part (12) and a screw part (13) when the material (10) is not restricted; and a fourth process (#4) of chamfering a chamfering part (17) on a bottom of the screw part (13), and using a fourth dice (14-4) and a fourth punch (15-4), which form a taper part (16) in the head part (11), to perform a final cold forging process when the material (10) is restricted.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a L-bolt,

The present invention relates to an L-bolt, an apparatus for manufacturing the L-bolt, and a manufacturing method thereof. More particularly, the present invention relates to an L-bolt, Bolt, a manufacturing apparatus and a manufacturing method of the L-bolt, which can solve the problem that the eccentric head portion is damaged, reduce the material cost, and improve the productivity.

In general, L-Bolt is a product that enters the pipe and plays a very important role in connecting the pipe to the pipe.

Unlike conventional hex bolts and flange bolts, the L-bolt forms an eccentricity of the header shape so that it can not be loosened after screw tightening.

The process of making L-bolts is a forming process and a rolling process.

As shown in FIG. 1, the forming process includes cutting a material (#CUT), primary molding (# 1D + 1P), secondary molding (# 2P), and tertiary molding (2D) using a heading machine + 3P), and fourth-order molding (trimming). Four-stage molding including cutting is continuously performed at one time.

The process of making an existing L-bolt requires two steps, the order of which is molding and trimming.

1) First, the molding process is performed in the order of material cutting, primary molding, and secondary molding. The body portion 1 and the thread portion 2 are formed. The head portion 3 is left with a margin for trimming in the next step, Thereby forming the part 3.

2) The molded product is trimmed in the trimming process.

Such a method requires two molding steps and also requires a scrap cut in the trimming process, which is economically disadvantageous.

In the case of L-bolts, bolts specially manufactured for piping are assembled with piping pipes and embedded in the ground.

The biggest functional feature of L-bolts is the leak-proofing bar, for which the mating and L-bolts must be tightly screwed.

However, in the conventional L-bolt manufactured by the trimming method, when a certain time has elapsed after fastening or fastening with the counterpart, the hair bulging sometimes occurs.

That is, in the L-bolt formed by the trimming process, the metal flow forming the head portion at the time of forming the head is broken as shown in FIG. 2, and when the metal flow is broken, the durability of the product is weakened, The header was often damaged.

In the conventional L-bolt forming process, as shown in FIG. 3, the cut material must be extruded during the forging process to make the threaded portion 2, and then the lower end portion 4 should be chamfered. The cross-section must be pre-shaped in the shape of a flower pebble or a jar.

In other words, both the die 5 and the punch 6 are subjected to a large load because extrusion, chamfering, and preforming must be performed in one process.

In addition, when the mold structure is viewed as a single mold without dividing the mold, it is difficult to repair the mold when the mold is broken due to a small impact, and a new mold must be manufactured at the time of breakage.

The secondary molding (# 2P) is a step of preforming the head part (3) to make it round.

In the trimming process, after the trimmed tip 8 is inserted into the trimming punch 7, the molded product is inserted between the trimming die 9 and the trimming tip 8, and then the trimming punch 7 is moved In the step of trimming, the molded product is caught in the trimming tip 8, and unnecessary parts are cut off.

At this time, when an unnecessary portion is cut off from the trimming tip 8, a large load is applied to the trimming tip 8, so that the trimming tip 8 is severely damaged, resulting in a large number of defects.

KR Patent No. 10-2008-0086015 KR Patent No. 10-0672864

The L-bolt to be provided in the present invention and its manufacturing apparatus and manufacturing method are provided with an L-bolt capable of solving the problem that the head portion of the L-bolt is broken during use, and a manufacturing apparatus and a manufacturing method thereof.

Also, the present invention is to provide an L-bolt manufacturing method and a manufacturing apparatus capable of remarkably reducing material costs and maximizing productivity during L-bolt manufacturing.

Also, the present invention is to provide an L-bolt, a method of manufacturing the L-bolt, and an apparatus for manufacturing the L-bolt, which can overcome the problems of increase in cost due to die breakage and increase in defect due to trimming tip breakage.

As a specific means for solving the problems of the above-mentioned invention, in an L-bolt manufacturing apparatus for producing an L-bolt using a former, The manufacturing apparatus includes first to fourth dies for restricting a workpiece; A first sliding punch for primary preforming so as to form an eccentric head on the material constrained to the first die; A second punch for secondary molding such that the upper part of the eccentric head is flat on the primary preformed material constrained to the second die; A third punch for forming a head portion eccentrically formed in the secondary molded workpiece constrained to the third die and for forming a threaded portion by extruding the head portion to generate a step in the body portion; And a fourth punch for forming a chamfered portion at the lower end of the threaded portion and a fourth punch for forming a head portion of the third preformed head portion and the threaded portion constrained to the fourth die, And three mold halves divided into first, second and third molds so as to reduce the breakage rate caused by the first and second molds; A first and second bushes for covering the first, second and third molds from the outside; And a third bushing formed to surround the first and second bushes once more from the outside of the first and second bushes to enhance the durability of the first to fourth dice; The first mold is tapered to prevent the first mold from being disengaged when the load is applied. The first slide punch is easily preformed in the first preform of the eccentric head while the material is constrained to the first die The second punch and the third punch are configured to be capable of being assembled and detached by screwing for easy replacement at the time of breakage .
In addition, the L-bolt manufacturing method using the L-bolt manufacturing apparatus is characterized in that the L-bolt is manufactured by continuous cold forging of 1 to 4 stages, and the material cut by a predetermined length is cut into the first die and the first sliding punch A first preliminary step for forming L-bolts so that the head is eccentric in one direction; A second step of secondary molding the head portion of the L-bolt that has been preformed in the first step so that the head portion is flattened by the second die and the second punch; A third step of molding the head part of the L-bolt secondary molded in the above step by a third die and a third punch and molding the screw part by extruding the head part so that a step is generated in the body part; And a fourth step of performing cold forging in a state in which the material is constrained by using a fourth die and a fourth punch for forming a tapered portion on the head portion in addition to the face attachment molding at the lower end of the screw portion, The preform is first preliminarily molded so as to be eccentrically eccentric, and then the eccentric head is continuously formed in the two-step process and the three-step process, and is manufactured by only cold forging without trimming process.

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Further, the present invention provides L-bolts excellent in durability manufactured by the L-bolt manufacturing apparatus.

The L-bolts and the manufacturing apparatus and the manufacturing method thereof according to the present invention make it possible to manufacture L-bolts having an eccentric head by a four-step cold forging process without a trimming process, thereby reducing materials, You can contribute,

Bolt's eccentric head can be produced without trimming process, and it is possible to provide high-quality L-Bolt that maximizes product durability because metal flow is alive,

The durability of the manufacturing apparatus can be improved, and the convenience of exchange repairing can be provided upon breakage.

1 is an overall process diagram showing a conventional L-bolt manufacturing method
2 is a front view and a plan view showing a metal flow of an L-bolt manufactured by a conventional L-bolt manufacturing method
3 is a cross-sectional view showing a configuration of a conventional L-bolt manufacturing apparatus
4 is a cross-sectional view showing a trimming apparatus and a process in a conventional L-bolt manufacturing apparatus
5 is a perspective view showing the L-bolt provided by the present invention.
6 is a process diagram showing a method for producing an L-bolt provided by the present invention
7 is a front view and a plan view showing the metal flow of the L-bolt manufactured by the L-bolt manufacturing method of the present invention.
8A to 8B are perspective views showing the L-bolt manufacturing apparatus of the present invention.
9 is a sectional view showing the L-bolt manufacturing apparatus of the present invention and the sequential steps of the first to fourth steps
FIG. 10A is a perspective view showing the arrangement of the dies of the L-bolt manufacturing apparatus according to the present invention,
10B is a cross-sectional view of the combined state of FIG.
11 is a cross-sectional view showing a load applied during L-bolt molding using the die of the L-bolt manufacturing apparatus of the present invention
12 is a cross-sectional view showing the configuration and operation of the punch used in the one-step molding process of the L-bolt manufacturing apparatus of the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that, in the drawings, the same components or parts have the same reference numerals as much as possible. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as to avoid obscuring the subject matter of the present invention.

As used herein, the terms "substantially", "substantially", and the like are used herein to refer to a value in or near the numerical value when presenting manufacturing and material tolerances inherent in the meanings mentioned, Absolute numbers are used to prevent unauthorized exploitation by unauthorized intruders of the mentioned disclosure.

The present invention is characterized by providing an L-bolt excellent in head durability. Further, the present invention provides a manufacturing apparatus and a manufacturing process for manufacturing the L-bolt.

The L-bolt manufacturing process is manufactured through a four-step process without a trimming process in a former. In the first step process, a cut material having a predetermined length is inserted into a dice, The head is eccentrically formed by dies and punches in the two-step process. In the three-step process, the eccentric head is formed by the third molding and the stepped portion between the body portion and the thread portion is generated In the four-step process, the L-bolt is manufactured by finally forming the tapered portion in the head portion in addition to the face-fitting molding at the bottom of the screw portion.

The die used in the L-bolt manufacturing apparatus is composed of a split mold that is divided into a plurality of horizontally, and a plurality of bushes are enclosed in a double manner to maximize the durability. The upper split mold is made into a tapered shape, Prevent escape from work. In addition, the punch used in the first step process is made of sliding punch, and the punch used in the second to third step process is tapped so that it can be exchanged in case of breakage, so that screw assembly and separation can be performed.

FIG. 5 is a photograph of an L-bolt provided in the present invention, and FIG. 6 is a process diagram showing a method of manufacturing an L-bolt provided in the present invention.

The L-bolt and the manufacturing apparatus and the manufacturing method thereof according to the present invention are characterized in that the L-bolt is manufactured by a so-called 'upsetting' method.

The 'upsetting' is a forging operation in which the material is axially compressed in the forging operation to shorten the length and increase the cross section.

The L-bolt manufacturing method including the conventional trimming method requires two steps of a molding process and a trimming process. However, since the upsetting method according to the present invention solves all at once, the process itself can be cut in half, Saving, and improved durability.

According to the present invention, L-bolts are manufactured by cold forging while the four steps (# 1D to # 4D) are continuously performed by a former (forming machine).

Bolts are formed in the first die (14-1) and the first sliding punch (15-1) such that the head (10) is eccentric in one direction in the first step (# 1D) Primary preforming is performed.

In the second step (# 2D), the head 11 of the L-bolt that has been preformed in the first step is secondarily molded again by the second die 14-2 and the second punch 15-2 .

In the third step (# 3D), the head 11 of the secondary molded L-bolt is thirdly molded by the third die 14-3 and the third punch 15-3, 12 so as to form a stepped portion to form the threaded portion 13.

The fourth dies 14-4 for forming the tapered portions 16 and the fourth dies 14-4 for forming the tapered portions 16 are formed on the head 11 in addition to the forming of the chamfered portions 17 at the lower end of the threaded portion 13 of the L- The punch 15-4 is used for final cold forging in a state where the workpiece 10 is restrained.

Finally, the threads of the L-bolt thread 13 are separately rolled through the rolling process, thereby manufacturing the L-bolt.

The L-bolt of the present invention manufactured through the above-described manufacturing method has a trimming process that is short compared to the L-bolt manufacturing method including the conventional trimming process, which leads to an increase in the production amount.

When comparing the weight of the material of the conventional trimming method and the method of up-setting according to the present invention, in the case of the L-bolt forming work including trimming, the material weight is required to be 250 g when manufacturing the same L-bolt, The method is possible if the material weight is 170g.

That is, the conventional trimming method requires about 80 g of material. For example, when the material price is 1,500 won per kg, the cost can be reduced by 120 won when the L-bolt according to the present invention is manufactured will be.

Also, the L-bolt according to the present invention can produce a strong and durable product, as shown in FIG. 7, in which the metal flow is alive (meaning that it is connected without breaking).

On the other hand, the dies and punches for producing L-bolts according to the present invention, that is, a manufacturing apparatus will be described in more detail below.

8A to 8B are perspective views showing the L-bolt manufacturing apparatus of the present invention.

As shown in the entire process chart of the L-bolt manufacturing apparatus shown in FIG. 9, the manufacturing apparatus for manufacturing the L-bolts provided in the present invention is composed of first to fourth dies 14-1, 14-2, 14-3, The first sliding punch 15-1 and the second to fourth punches 15-2, 15-3, and 15-4.

When the preforming step of the head part 11 is carried out with the material 10 cut to a predetermined length for manufacturing the L-bolt, the head part 11 is formed to be eccentric.

As shown in FIG. 3, when the head 11 is formed into a garden shape, the direction of the force spreads evenly, which is good for working but the mold breakage rate is high.

That is, in the conventional mold shown in FIG. 3, since the die receiving the force of the punch has a single structure, the die can not receive the force applied by the punch, so that the die is easily broken.

Accordingly, in order to minimize the mold breakage rate, the present invention is applicable to the first to fourth dies (14-1, 14-2, 14-3, 14-4) and the first to fourth dies The first sliding punch 15-1 and the second, third, and fourth punches 15-2, 15-3, and 15-4.

The L-bolt manufacturing apparatus of the present invention is manufactured by dividing the first to fourth dies 14-1, 14-2, 14-3, and 14-4 into a plurality of dies instead of a single die, . Such a plurality of dies are called 'split molds' or 'divide dies'.

Referring to FIG. 9, the first to fourth dies 14-1, 14-2, 14-3, and 14-4 used in the first to fourth steps (# 1D to # 4D) for manufacturing the L- - Although there are differences in detail structure and shape to form the shape of the bolt step by step, the constitution has the same characteristics.

10A is an exploded perspective view showing a die structure of the L-bolt manufacturing apparatus according to an embodiment of the present invention, and FIG. 10B is a cross-sectional view showing a coupled state of FIG. 10A. 14-1, 14-2, 14-3, and 14-4 are made of three metal carbide molds divided into first, second and third molds 14a, 14b, and 14c, A third bush 14f for once covering the first and second bushes 14d and 14e from the outside with the first and second bushes 14d and 14e for covering the three molds 14a, 14b and 14c from the outside, .

That is, if the first to fourth dies 14-1, 14-2, 14-3, and 14-4 are made of double bushes, the first to fourth dies 14-1, 14-2, 14 3 and 14-4 are once again blocked from the first, second and third dies 14a, 14b and 14c by the first and second bushes 14d and 14e, Four dice 14-1, 14-2, 14-3, and 14-4 can be manufactured.

When the first sliding punch 15-1 and the second, third, and fourth punches 15-2, 15-3, and 15-4 are loaded, the first metal mold 14a is tapered. So as to prevent the first mold 14a from protruding.

11, the first sliding punch 15-1 and the second, third, and fourth punches 15-2 and 15-7 in the structure of the first, second, and third dies 14a, 14b, The first mold 14a is tapered and the first mold 14a is larger than the second and third molds 14b and 14c located below the first mold 14a, By making it able to withstand the load, the anti-electric power is maximized.

The first sliding punch 15-1 used in the first step # 1D is formed with the eccentric shape of the head part 11, so that it can not be formed in a desired shape when working with a punch.

The present invention is characterized in that the first sliding punch 15-a configured to slide on the outer periphery of the punch pin 15c for pressing the workpiece 10 by elasticity to the spring 15b, 1) so as to concentrate on the preforming of the head part 11.

In addition to the preliminary forming of the head part 11, when the first sliding punch 15-1 is used to mold other shapes simultaneously, more force is required, which causes the mold breakage.

The L-bolt manufacturing apparatus of the present invention is designed so that there is no space between the first die 14-1 and the first sliding punch 15-1, and the work 10 is constrained to accurately shape the head 11 So that it can be molded.

Unlike the first step process, the second preformed head 11 is constrained to the second die 14-2 and then the second punch 15-2 is used to move the head 11). At this time, the upper part of the head 11 is formed flat.

The second punch 15-2 is designed to have a double bush structure in order to make the second dice 14-2 having a high durability even though the second punch 15-2 does not require a larger force than the first step (# 1D) Allows for easy tap-fit for screw-in assembly and disassembly.

If the emphasis is placed on the shape of the head 11 in the first stage (# 1D) and the second stage (# 2D), the third stage (# 3D) process is designed to focus the outer diameter of the thread 13 to be.

Of course, the inner shape of the third die 14-3 is designed by the same method in all of the first to fourth steps, and in order to make the outer diameter of the threaded portion 13, for example, when the outer diameter is 17.86 mm, the outer diameter is made 16.13 mm.

Like the second step (# 2D) step, the third punch 15-3 is also tap-operated so that it can be easily assembled and detached to be replaced when broken.

The fourth step (# 4D) is the final step of molding. In the fourth punch 15-4, the tapered portion 16 is formed by the finish molding operation of the head 11, At the side of the die 14-4, the lower end portion of the threaded portion 13 is flattened to assemble the product easily when the product is assembled.

The fourth die 14-4 used in the fourth step (# 4D) is also manufactured with a split mold and a double bush structure in the same manner as the first step (# 1D) to make the durability strong, and the fourth punch 15- 4) is a tip type (or fitting type) so that it can be easily disassembled and assembled at the time of breakage.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Rather, the scope of the following claims is to be accorded the scope of the claims and equivalents thereof to equivalents thereof.

10: material 11: head 12: body 13: thread
14-1: 1st dice
14-2: 2nd dice
14-3: Third Dice
14-4: Fourth Dice
14a, 14b, 14c: first, second and third molds 14d: first bush 14e: second bush 14f: third bush
15-1: First slide punch 15a: Sliding punch 15b: Spring 15c: Punch pin
15-2: second punch
15-3: Third punch
15-4: fourth punch
16: tapered portion 17:

Claims (5)

An L-bolt manufacturing apparatus for manufacturing an L-bolt using a former;
The manufacturing apparatus comprises first to fourth dies (14-1, 14-2, 14-3, 14-4) for restricting the work (10);
A first sliding punch 15-1 for primary preforming to form an eccentric head 11 on the workpiece 10 constrained to the first die 14-1;
A second punch 15-2 for secondary molding so that the upper portion of the eccentric head 11 is flat on the primary preformed workpiece 10 constrained to the second die 14-2;
The eccentric head 11 is thirdly molded in the secondary molded workpiece 10 constrained to the third die 14-3 and extruded so that a step is generated in the body 12, A third punch 15-3 for forming the first punch 15-3;
A tapered portion 16 and a screw portion 13 are formed on the head 11 of the formed workpiece 10 in which the third preformed head 11 and the screw portion 13 constrained to the fourth die 14-4 are formed. And a fourth punch 15-4 for forming the chamfered portion 17 at the lower end,
The first to fourth dies 14-1, 14-2, 14-3, and 14-4 are divided into first, second, and third dies 14a, 14b, 14c so as to reduce the breakage rate due to punching Three molds; First and second bushes 14d and 14e for covering the first, second and third molds 14a, 14b and 14c from the outside; The first and second dies 14-1, 14-2, 14-3, and 14-4 are formed so as to surround the first and second bushes 14d and 14e once more in a double structure to increase the durability of the first to fourth dies 14-1, 14-2, And a third bush 14f; The first mold 14a is tapered to prevent the first mold 14a from being separated during a load operation,
The first sliding punch 15-1 is configured to pivot the punch pin 15c so as to facilitate primary preforming of the eccentric head 11 in a state where the workpiece 10 is constrained to the first die 14-1. The sliding punch 15a is configured to slide on the outer periphery by the elasticity of the spring 15b,
And the second punch (15-2) and the third punch (15-3) are configured to be assembled and detached in a threaded manner for easy replacement at the time of breakage.
The L-bolt is produced by one to four successive cold forging using the L-bolt manufacturing apparatus of claim 1,
The material 10 cut by a predetermined length is subjected to primary preforming 1 to form L-bolts so that the head is eccentric in one direction by the first die 14-1 and the first sliding punch 15-1 A step (# 1D);
The head portion 11 of the L-bolt that has been preliminarily preformed in the first step (# 1D) is placed on the upper portion of the head portion 11 by the second die 14-2 and the second punch 15-2 A second step (# 2D) of secondary molding so as to be flat;
The head portion 11 of the L-bolt that is secondarily molded in the second step (# 2D) is thirdly molded by the third die 14-3 and the third punch 15-3, (# 3D) step of extruding the screw part (12) so as to form a step so as to form the screw part (13);
A fourth die 14-4 and a fourth punch 15-4 for forming the tapered portion 16 are formed on the head 11 in addition to forming the chamfered portion 17 at the lower end of the screw portion 13, (# 4D) step of final cold forging in a state in which the base member 10 is restrained,
(# 2D) and a step # 3 (3D), the head 11 is formed in the first stage (# 1D) so that the head is eccentric, Wherein the L-bolt is manufactured by cold forging only.
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