KR20080005909A - Method for manufacturing anchor rivet - Google Patents

Abstract

A method for manufacturing an anchor rivet is provided to increase productivity and to minimize a defective rate simultaneously. A method for manufacturing an anchor rivet includes a step of cutting a cylindrical material shorter than length of the anchor rivet(S1); a step of forming a cutting groove which is shorter than a cutting groove of a finished product, by using a punch after inserting the cut material into a mold(S2); a step of extending the length of the cutting groove and reducing the length of slit width for the cutting groove, by increasing the length of the body unit by inserting and punching a semi-finished product into the mold with a smaller diameter(S3); a step of extending the length of the body and forming an insertion hole inside the body simultaneously, by inserting and punching the semi-finished product into the mold(4a) with the smaller diameter(S4); and a step of finishing a head at a rear end portion by inserting and punching the semi-finished product into the other mold(4b)(S5).

Description

Method for manufacturing anchor rivets

The present invention relates to an anchor rivet, and more particularly, to a method of manufacturing an anchor rivet configured to minimize the defect rate, such as to prevent damage to the mold for manufacturing as much as possible, to increase the productivity.

A perspective view of a general anchor rivet is shown in FIG. 1, and a state of use of the anchor rivet is shown in FIG. 2. As shown, the general anchor rivet 10 includes a body 14 inserted into the fastening object and a head 12 formed at the rear end of the body. A cross-shaped cutout groove 13 is formed at the front end of the body 14, and the insertion hole 15 is formed in the longitudinal direction at the rear end of the head 12.

The anchor rivet 10 is inserted into a hole formed in two materials (for example, metal plates) to be riveted, and then the pin P as shown in FIG. 2 has a length of the insertion hole 15. By pressing in the direction, the distal end portion of the body 14 is extended radially. By extending the front end of the body 14, the two parts to be fastened and fixed are kept in a completely fixed state with each other.

Various methods for producing such anchor rivets have been proposed. For example, in the method of forming the notch groove, it may be cut using a saw or the insertion hole is molded using a predetermined punch. And according to the Republic of Korea Patent Publication No. 10-0420273, a technique for forming the cut groove and the insertion hole using a predetermined mold is disclosed.

However, according to this technique, when forming the cross-shaped cutout groove, since the entire shape of the anchor rivet is molded first, and then the cutout groove is formed to a set depth, the defective rate in the process of processing to the desired depth when forming the cutout groove. This may increase. In addition, since the mold for forming the cross-shaped cutout groove has a single circular shape, it is not easy to replace the mold. In addition, in the molding of the insertion hole, since the insertion hole is formed after the head molding is completed, there is a problem that a bur is generated in the head portion, and thus, unless a separate cutting process is performed again. The troublesome thing is pointed out.

After the pin is inserted, since the inner diameter of the insertion hole is a simple circle, a phenomenon in which the pin is randomly released occurs. The detachment of the pins results in a drastic drop in the fastening force of the anchor rivets, which substantially affects the function of the anchor rivets.

The present invention is to solve the conventional problems as described above, it is an object of the present invention to provide a method for manufacturing an anchor rivet that is simple to manufacture, to minimize the defective rate and to increase productivity.

Another object of the present invention is to provide an anchor rivet that is configured to completely prevent a drop in fastening force, and can maintain a reliable fastening state.

According to the present invention for achieving the above object, the present invention is a method of forming a cylindrical material with an anchor rivet using a mold; A first step of cutting the cylindrical material shorter than the length of the anchor rivet; A second process of inserting the cut material into a mold to form a notch groove having a relatively short length compared to the notch groove of the finished product by using a punch; A third step of reducing the slit width of the cutout groove while extending the length of the cutout groove by inserting and punching the semi-finished product formed in the second process into a mold having a relatively small diameter to extend the length of the body; A fourth process of inserting the semi-finished product formed in the third process into a mold having a relatively small diameter and punching the same to extend the length of the body and to form an insertion hole in the body; And a fifth process of finishing the head at the rear end by punching the semi-finished product formed in the fourth process into another mold.

According to another feature of the invention the invention is a method of forming a cylindrical material with an anchor rivet using a mold; A first step of cutting the cylindrical material shorter than the length of the anchor rivet; A second process of inserting the cut material into a mold to form a notch groove that is relatively shorter than that of the finished product at one end by using a punch; Inserting a semi-finished product having a notched groove into a mold, and forming a first head at the other end by using a punch; A fourth process of inserting the semi-finished product formed in the third process into a mold and forming an insertion hole therein by using a punch; And a fifth process of inserting a semi-finished product having an insertion hole into a mold and using a punch to reduce the volume of the first head portion to form a complete head shape; In at least one of the second to fourth processes, the length of the cutout groove and the length of the body are completed to the length of the finished product by simultaneously extending the length of the material or semi-finished product.

According to the present invention as described above it can be expected the following effects.

In the present invention, since the material (a state) having a relatively large diameter and a short state are processed by using a mold and the length is sequentially formed sequentially, the depth can be formed shallowly when forming the notched groove. Do. Therefore, it is possible to sufficiently prevent the eccentricity of the notch groove portion, and at the same time it is possible to prevent the damage of the mold for forming the notch groove to the maximum.

In the present invention, since the head portion is sequentially formed after the insertion hole is formed, it is possible to prevent the occurrence of burrs due to the formation of the insertion hole after the head formation, and does not require a separate cutting process. Therefore, it will be obvious that there is a more advantageous advantage in improving productivity, and an effect that the head portion can be formed in an accurate circle is also expected.

In the present invention, since the protrusion 17 is formed on the inner circumference of the insertion hole, the separation of the pin inserted into the insertion hole of the anchor rivet can be reliably prevented, and thus the advantage of being able to further improve the reliability of the product is provided. It is expected.

Next, the present invention will be described in more detail with reference to the embodiments shown in the drawings.

As can be seen with reference to Figure 3, in order to make the anchor rivet according to the present invention, first, the raw material provided in a cylindrical shape is cut to a predetermined length. At this time, the length of the raw material is cut shorter than the length of the anchor rivet that is substantially completed. And the diameter of a raw material is large compared with the diameter of the anchor rivet which is substantially completed. The anchor rivet completed in the following description will be referred to each part using the reference numerals shown in FIG.

In FIG. 1, reference numerals 2a and 2b denote mold holders capable of supporting a mold, reference numeral 4 denotes a mold, and reference numeral 6 denotes an eject pin for ejecting an object. In the first step S1, the raw material M cut to a predetermined length is put into the mold 4 supported by the mold holders 2a and 2b, and the raw material M in this state is in a state ( is shown as a). Here, the mold 4 is a mold for forming the cutout groove 13, and thus has a shape corresponding to the cutout groove 13 of the anchor rivet 10.

In this way, after the raw material is injected into the die 4, in the second process S2, the punch is pressed using the punch P1. After the pressurization is performed, as shown in the third process S3, the pin 6 is advanced to take out the semi-finished product from the mold. In this third process, the semi-finished product taken out by the pin 6 is shown in state (b). This semi-finished product is formed with a notch groove 13 with respect to the cylindrical body as shown, and this notch groove 13 is a cross-shaped groove as shown in FIG. And the notch groove 13 formed in the second process (S2) is formed shallower than the depth of the notch groove of the finished product.

And the semifinished product shown in state (b) is a state in which the length extended substantially more than the semifinished product shown in state (a). An extended length means that the diameter of the material is substantially reduced because the volume of the material is the same. In addition, in order to extend the length of the semi-finished product (or material) means the same as using a mold in a state in which the diameter of the mold cavity is further reduced, and will be used as the same meaning in the following description.

Next, in the fourth step S4, the semi-finished product of the state (b) is put into another mold 4a, and the forging process is performed by pressing the punch P2 and then forging the pin 6a by forging. You get a semifinished product that is marked as processed (c). The semi-finished product in the (c) state is substantially formed by the shape of the mold 4a, and at the same time, the length of the semi-finished product is longer than that of the semi-finished product in the (b) state. In addition, the primary head portion 12a is slightly different from the shape of the head 12 of the completed anchor rivet 10 (the volume is relatively large), and the shape of the complete head 12 through the process described below. Will have.

Next, in the fifth step S5, the semi-finished product in the state (c) is placed in another mold 4b and pressed with a punch P3. At this time, the punch (P3) is substantially for forming the insertion hole 15 of the anchor rivet 10, it is natural that has a predetermined shape for forming the insertion hole (15). After the forging process of the fifth process is performed, the semi-finished product is taken out by the pin 6b. The semifinished product having passed through the fifth process is molded as in the state (d). That is, the insertion hole 15 is formed in the primary head part 12a by the said punch P3.

When the semi-finished product of the above state (d) is put into another mold 4c in the sixth step, pressurized using the punch P4, and taken out to the pin 6c, the semi-finished product of the state (e) is obtained. That is, the punch P4 is for molding the secondary head portion 12b, and the secondary head portion 12b is halfway between the primary head portion 12a described above and the head 12 of the finished product. It has a shape.

In the seventh process, the finished product of the anchor rivet is obtained by putting the semi-finished product of the state (e) back into another mold 4d and pressing it using a punch P5 to obtain the finished product of the anchor rivet. It is shown in state f.

In the seventh process, as described above, the punch P5 is molded into a complete head shape and the following process is performed. A groove portion P5a of a predetermined length is formed at the tip end of the punch P5. In the state in which the tip 12 of the punch P5 enters the inside of the insertion groove 15, the completed shape of the head 12 (refer to the product drawing after the seventh process) is formed. The protrusion 17 shown in FIG. 5 is formed inside 15. 5 is a front view as seen from the head 12 side of the anchor rivet 10 of the present invention, it can be seen that the inside of the insertion hole 15 is formed with a protrusion 17 protruding inward, such a protrusion Reference numeral 17 is formed in the seventh process by the punch P5.

As in the illustrated embodiment, a plurality of projections 17 (three in the illustrated embodiment) are formed at predetermined intervals (preferably equal intervals) inside the insertion hole 15. As shown in FIG. 1, the protrusion 17 is for preventing the pin P inserted into the insertion hole 15 of the anchor rivet 10 from being arbitrarily separated. That is, when the pin P is inserted into the insertion hole 15 of the anchor rivet of the present invention, the protrusion 17 is deformed while being completely in contact with the pin P to prevent the pin P from being separated. The friction force can be applied. Therefore, as the protrusion 17 is deformed, the pin P is not detached from the anchor rivet arbitrarily, thereby making it possible to provide a stronger clamping force.

FIG. 4 illustrates a process of completely forming the anchor rivet of the present invention through each process of FIG. 3, wherein (a) to (f) have the same state as in FIGS. It is shown.

As can be seen from this, the state shown in (b) goes through the first process (S1), the second process (S2), and the third process (S3) in the work state shown in (a). do. It can be seen that the state shown in (b) is longer than the state shown in (a). And the semi-finished product in the (b) state, again through the fourth step (S4) is in the state shown in (c), it can be seen that the (c) state also has a longer length than the (b) state . In addition, the semi-finished product in the state (c), the length is again extended through the fifth process (S5) to enter the state (d). As described above, in the present invention, it can be seen that the length of the anchor rivet is made to be the desired length through various processes. By going through such several processes, it is possible to finally form an anchor rivet having a notch groove of a desired depth even when the depth of the notch groove 11 is relatively shallow.

Therefore, since the first step of forming the notch groove is formed relatively shallow notch groove in the relatively large diameter material, it is possible to prevent the portion in which the notch groove is formed to be eccentric, thereby minimizing the defective rate.

In the process of forming the head 12 in the state of the finished product (f) in the semi-finished state (d), the volume of the portion is reduced through the primary head portion, the secondary head portion, and the finished head 12. Through the forging process, it can be seen that the predetermined protrusion 17 is formed inside the insertion hole 15, and the protrusion 17 maintains the state in which the pin P of the anchor rivet is more firmly fastened. It can be seen that. In the above embodiment, the head is formed through a process such as a primary head part, a secondary head part, etc., but the process of making a complete head may be performed more than in the above embodiment, and may be performed at least two or more times. It may be further simplified to go through.

According to the present invention, by first forming the insertion hole 15 in the fifth process (S5) as described above, and then proceeding the forging process to form the head 12 portion, substantially due to the formation of holes It is possible to prevent the occurrence of bur in the peripheral portion, it is not necessary to perform a separate cutting process.

And the mold shown in the description of the present invention described above is an example, various modifications are possible in the portion forming the anchor rivet of the present invention as described above, of course. It is apparent that the present invention should be interpreted based on the appended claims.

1 is a perspective view of a typical anchor rivet.

2 is an explanatory view of a general anchor rivet.

3 is an exemplary process diagram sequentially illustrating the process of the present invention.

Figure 4 is an exemplary view showing a deformation process of the material according to the present invention.

Figure 5 is a front view as seen from the head side of the anchor rivet completed by the present invention.

Claims (2)

A method of forming a cylindrical material into an anchor rivet using a mold; A first step of cutting the cylindrical material shorter than the length of the anchor rivet; A second process of inserting the cut material into a mold to form a notch groove having a relatively short length compared to the notch groove of the finished product by using a punch; A third step of reducing the slit width of the cutout groove while extending the length of the cutout groove by inserting and punching the semi-finished product formed in the second process into a mold having a relatively small diameter to extend the length of the body; A fourth process of inserting the semi-finished product formed in the third process into a mold having a relatively small diameter and punching the same to extend the length of the body and to form an insertion hole in the body; And And a fifth process of finishing the head at the rear end by punching the semi-finished product formed in the fourth process into another mold. A method of forming a cylindrical material into an anchor rivet using a mold; A first step of cutting the cylindrical material shorter than the length of the anchor rivet; A second process of inserting the cut material into a mold to form a notch groove that is relatively shorter than that of the finished product at one end by using a punch; Inserting a semi-finished product having a notched groove into a mold, and forming a first head at the other end by using a punch; A fourth process of inserting the semi-finished product formed in the third process into a mold and forming an insertion hole therein by using a punch; And And a fifth process of inserting a semi-finished product having an insertion hole into a mold and using a punch to reduce the volume of the first head portion to form a complete head shape; In at least one of the second to fourth processes, the length of the material or semi-finished product is carried out at the same time to complete the length of the notched groove and the length of the body to the length of the finished product anchor rivet Manufacturing method.

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