KR100877240B1 - Insert-steel rod and method thereof - Google Patents

Abstract

The present invention relates to a method for manufacturing a steel bar for inserts, comprising the steps of: (a) preparing a steel bar of a predetermined length whose diameter at one end is smaller than the total diameter; (b) inserting one end of the steel bar into the inlet side of the inner mold having a plurality of cutting tips radially formed on an inner circumferential surface thereof; And (c) forming a plurality of grooves in the longitudinal direction of the steel rod by drawing the steel rod through the outlet side of the outer mold extending gradually from the end of the inner mold and having a radius larger than the radius of the inner mold; Insert (steel) manufacturing method for an insert, characterized in that it comprises a.

Description

Insert steel rod and method of manufacturing the same

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to

1 is a perspective view schematically showing a rod for a general insert (semi-finished product).

Figure 2 is a flow chart of a method for manufacturing a steel rod for inserts according to a preferred embodiment of the present invention.

Figure 3 is a process chart of the steel bar manufacturing method for an insert according to a preferred embodiment of the present invention.

Figure 4 is an exploded perspective view of the die for producing the insert steel bar according to a preferred embodiment of the present invention.

5 is a cross-sectional view of the combination of FIG.

<Description of the symbols for the main parts of the drawings>

1.Steel bar 3 ... Front end 5 ... Grip feeder

10 Inner mold 12 Cutting tip 14 Inlet side

20.External mold 22.Jump 24.Exit side

100 ... dice

The present invention relates to a method for manufacturing a steel rod for an insert and a steel rod for an insert according to the present invention, and more particularly, to continuously inserting steel rods for semi-finished inserts having a plurality of radial grooves formed in the longitudinal direction on an outer circumferential surface of a raw steel rod having a circular cross section. The present invention relates to a method for manufacturing steel bars for inserts and to semi-finished steel bars for inserts.

In general, in order to fix a screw or bolt to an injection molded product, an insert is pre-installed on the injection molded product, and a screw or bolt is coupled into a hole formed in the insert. In addition, an insert to be installed in an injection molded product having various shapes and structures has various dimensions (diameter, length, etc.) determined according to the required structure of the injection molded product. Therefore, many kinds of insert rods (steel rods or brass rods) are manufactured and distributed in the form of semi-finished products so that the user can appropriately cut and drill a predetermined hole in the cut portion so as to meet the insert dimensions required by the industry. have. As a result, a user purchases a rod for a semi-finished insert, cuts it to a required dimension, and produces an insert of a predetermined form through a separate processing.

Figure 1 shows an insert rod in the form of a general semifinished product.

By the way, in the case of brass rods, the raw material can be manufactured directly into the insert brass by a drawing method, while in the case of steel rods, a process of rubbing the steel rods between the molds by putting the first drawn steel rods between a pair of molds It is common to produce steel rods 1 for inserts. This is because, in the case of brass rods, it is possible to extract the soft material by drawing because the hardness of the material is not high and the workability is excellent. However, in the case of steel bars, it is almost impossible to manufacture the raw material by drawing process from raw materials.

However, according to this conventional method, the grooves formed on the surface of the steel bar 1 of the final semi-finished form to be produced because the cutting performance of the mold for manufacturing the insert steel bar itself is inferior, or even the portion where the grooves are not formed. There is a high probability of failure of the finished product. In addition, according to the prior art, the blade of the mold is broken, the blade is not sharp, the acid between the acid of the product to be produced is not constant, or the operator has to follow the additional sorting of the product to be produced.

In addition, according to the prior art, unlike the brass bar, if the steel bar for the insert (1) is produced in a pull-out method (so-called shaving), drawing the steel bar, the shaving operation itself is impossible due to the strength of the raw material steel bar Of course, the mold itself has a problem that the durability is lowered. For example, in the case of producing a 2.5m long product, when the shaving operation is performed, the product is stretched to a length of about 2.7m to 2.75m, so there is a problem that the specification of the product does not work and the probability of defect is high. . This work also has the disadvantage that additional work for sorting the final product is required.

 The present invention was devised to overcome the above-mentioned problems, and it is possible to stably and continuously manufacture a product having a uniform quality of a steel rod for inserts in the form of a semi-finished product on the surface of a steel rod having a circular cross section manufactured in the form of a drawing or the like. It is an object of the present invention to provide a method for manufacturing steel bars for inserts and steel bars for inserts accordingly.

Method for manufacturing a steel rod for inserts according to the present invention for achieving the above object, (a) preparing a steel bar of a predetermined length of the diameter of one end is smaller than the total diameter; (b) inserting one end of the steel bar into an inlet side of an inner mold in which a plurality of cutting tips are radially formed on an inner circumferential surface thereof; And (c) forming a plurality of grooves in the longitudinal direction of the steel bar by gradually extending from the end of the inner mold and extracting the steel bar through the outlet side of the outer mold having a radius larger than the radius of the inner mold. It includes; step.

Preferably, the inner mold is inserted into the outer mold to be fixed to the locking jaw of the outer mold so that the inner mold is not moved relative to the outer mold with respect to the traveling direction of the steel bar.

Preferably, the cutting tip has a length of about 2 mm to about 3 mm.

Preferably, the inner mold is made of cemented carbide.

Preferably, the inner mold and the outer mold are integrally made of cemented carbide.

Preferably, the cutting tip of the inner mold is coated by any one selected from TiN, TiC, TiCN, TiAlN.

Hereinafter, a method for manufacturing an insert steel bar according to a preferred embodiment of the present invention and an insert steel bar according thereto will be described in detail with reference to the accompanying drawings.

Figure 2 is a flow chart illustrating a method for manufacturing a steel rod for inserts according to a preferred embodiment of the present invention, Figure 3 is a process chart illustrating a specific method of manufacturing a steel bar for inserts according to a preferred embodiment of the present invention.

2 and 3, the steel bar manufacturing method according to a preferred embodiment of the present invention, the step of preparing a steel bar (1) having a diameter slightly smaller than the diameter in the longitudinal direction of the main body (S10) and the steel bar And inserting one end of (1) into the inlet side 14 of the die 100 having a predetermined structure (S20) and drawing out to the outlet side 24 of the die 100 (S30).

The steel bar 1 used in the step S10 is a rod having a straight shape that is substantially the same diameter and straight over its entire length by a drawing process, and one end thereof is a tip portion 3 having a diameter smaller than the diameter of the entire length. It is preferable that the distal end portion 3 has a length sufficient to pass through the die 100 and has a structure that can be gripped by the gripper transfer part 5.

The die 100 used in the step S20 has a form in which the inner mold 10 and the outer mold 20 are integrally coupled as shown in FIGS. 4 and 5.

The inner mold 10 is for forming a plurality of grooves of a predetermined shape in the longitudinal direction of the steel bar 1, a plurality of cutting tips 12 are formed on the inner peripheral surface to contact the surface of the steel bar (1). .

The outer mold 20 is gradually extended from the end of the inner mold 10, the outlet side having a larger diameter than the radius of the inner mold 10 and the large diameter portion from which the grooved steel bar 1 is drawn out ( Has 24).

In addition, the outer mold 20, when the steel bar 1 is advanced to form a plurality of grooves on the outer circumferential surface of the steel bar 1, the inner mold 10 is not moved relative to the outer mold 20 with respect to the traveling direction. The locking jaw 22 is provided to fix the position of the inner mold 10.

While the outer mold 20 is made of general steel, the inner mold 10 is preferably made of cemented carbide having excellent abrasion resistance and machinability. The cemented carbide used in the present embodiment preferably uses P series mainly in classification according to ISO (INTERNATIONAL STANDARD ORGANIZATION). On the other hand, the inner mold 10 is a high-speed steel that can obtain a relatively precise cutting edge, a ceramic tool for processing hard materials, Cermet, diamond steel, mainly sintered by adding a binder such as Ni, Mo, Cr, etc. Of course, various materials can be selected, such as CBN (CUBIC BORON NITRIDE), which is used to cut steel (HRC60 and above).

On the other hand, the length of the cutting tip 12 of the inner mold 10 is about 2mm to about 3mm. Of course, this length depends on the diameter of the steel bar 1 to be processed, but if the length is less than 2mm, the machinability is poor due to poor machinability, and if the length is larger than 3mm, the die 100 As the frictional force of the steel bar 1 itself is increased, workability is lowered, and there is a risk of damaging the surface of the product.

In order to prevent breakage of the internal mold 10 due to heat, the steel rod manufacturing die 100 according to the present embodiment may be supplied with a separate cutting oil from the outside (wet and dry), but the cutting of the internal mold 10 may be performed. The tip 12 can be subjected to a separate surface treatment with good lubricity. For example, the cutting tip 12 may be coated by any one selected from TiN, TiC, TiCN, TiAlN.

Therefore, in the die 100 in which the inner mold 10 and the outer mold 20 are integrated, the inner mold 10 and the outer mold 20 exist in the same plane in the plane of the inlet side 14, but the outlet side thereof. In 24, the plane of the inner mold 10 is inclined from the plane of the outer mold 20 to be inclined.

Referring to the specific process of the insert steel bar manufacturing method according to a preferred embodiment of the present invention configured as described above are as follows.

First, the leading end portion of the raw material steel bar 1 which has been drawn is inserted into the outlet side 24 of the outer mold 20 through the inlet side 14 of the inner mold of the die 100.

Subsequently, when the holding portion 5 is gripped by the holding portion 5 and the holding portion 5 is moved at a predetermined speed in the direction of the arrow “A”, the surface of the steel rod 1 is diced. Radial grooves are formed by the cutting portion of the inner mold 10 of 100. Here, the feeding speed of the gripping portion 5 depends on the diameter, strength, material of the cutting tip 12, and the like. In addition, the conveying direction of the gripping conveying part 5 is preferably linearly moved in a direction substantially coincident with the center of the steel bar 1 to ensure good machinability.

In addition, as shown in Figure 3, when the cross-section of the initial circular steel bar 1 is passed through the die 100 according to a preferred embodiment of the present invention by the cutting tip 12 of the inner mold 10 The cross section of the steel bar 1 is to form a groove radially.

The semi-finished insert steel bar manufactured through such a process can be cut and used in various forms required in the injection molding industry, and most of the cut parts are formed with holes or bolt holes to complete the final insert product.

In addition, according to the present invention On dice  Produced by Steel bar  In order to add a rotational force to be inserted into a general electrical appliance, it can be used for applications such as a shaft for transmitting the rotational force using the operator's hand or other tools. in this case, On steel bar  The groove formed is frictional and / or Grip  Function to increase

As described above, according to the manufacturing method of the steel bar for inserts according to the present invention has the following effects.

First, it is impossible to manufacture steel rods for semi-finished inserts by the drawing process of steel rods until now.

Compared with the prior art in which the quality of the product is degraded by the process of rubbing between the molds, it is possible to manufacture a stable and continuous insert steel bar while ensuring a uniform quality.

Second, the steel rod is inserted through the cutting tip of the inlet side formed in the inner mold of the small diameter and drawn out through the outlet side of the large diameter side of the outer mold, thereby preventing the breakage of the die that may occur in the processing of the insert steel rod. The die has a structure in which its position is fixed at the outer mold to increase the stability of the die, and if necessary, it can replace only the inner mold, thereby ensuring the reliability of the die product and facilitating the replacement of parts. Can be.

Third, by maintaining the optimum dimension of the cutting tip of the inner mold can prevent unnecessary delay of the work process according to the groove forming operation of the steel bar, as well as can extend the life of the die product.

Fourth, it is possible to reduce the screening process required in the prior art has the effect of reducing the labor costs.

As mentioned above, although this invention was demonstrated by the limited embodiment and drawing, this invention is not limited by this and is within the equal range of a common technical idea in the technical field to which this invention belongs, and a claim described below. Of course, various modifications and variations are possible.

Claims (7)

(a) preparing a steel rod of a predetermined length of a circle whose diameter is smaller than the entire diameter and not hollow; (b) inserting one end of the steel bar into an inlet side of an inner mold in which a plurality of cutting tips are radially formed on an inner circumferential surface thereof; And (c) the surface of the steel bar is cut by the cutting tip by passing the steel bar through the outlet side of the outer mold extending gradually from the end of the inner mold and having a radius greater than the radius of the inner mold; Forming a plurality of grooves in the longitudinal direction of the steel bar; The cutting tip has a length of about 2mm to about 3mm, and the inner mold is made of cemented carbide, characterized in that the insert (steel) manufacturing method for the insert (insert). The method of claim 1, The inner mold is inserted into the inner mold so that the inner mold is not moved relative to the outer mold relative to the traveling direction of the steel rod is manufactured by inserting the steel rod for the position fixed by the locking jaw of the outer mold Way. delete delete The method of claim 1, The inner mold and the outer mold is a steel rod manufacturing method for an insert, characterized in that made integrally with cemented carbide. The method of claim 1, The cutting tip of the inner mold is a steel rod manufacturing method for an insert, characterized in that the coating by any one selected from TiN, TiC, TiCN, TiAlN. Steel bar for inserts produced by any one of the methods of claims 1, 2, 5 and 6.

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