KR19980031992A - Injection Mold - Google Patents

Abstract

According to the present invention, a first block member having a hollow portion integrally fastened and having a hollow portion, a second block member having a hollow portion having upper and lower flange corresponding portions to which the flange can correspond, and inserted into a hole formed in the flange A rod member fixed between the upper and lower flange counterparts to guide the flange, an elastic member disposed between an upper surface of the flange and a bottom face of the upper flange counterpart, and the first block member and the second block member An injection molding die is provided that includes a core member that can be inserted into a hollow portion of the.

Description

Injection Mold

The present invention relates to a mold for injection molding, and more particularly, to a mold capable of injection molding a product including a portion where an undercut is formed.

In general, the injection molding mold may be manufactured in various forms according to the shape of the desired product. The mold should not only be manufactured in consideration of the characteristics of the injection molding material, but also should be manufactured in consideration of the ease of removing the mold after the solidification of the material is finished. In particular, if the shape of the product includes an undercut, the product may be damaged when the mold is removed, so measures should be taken.

1 is a perspective view showing an example of a product including an undercut, which is a tank of an automobile radiator. Referring to the drawings, the tank 10 is integrally formed with a duct 11 into which the medium for heat exchange can be injected, and the jaw portion 12 is formed at the end of the duct 11 along its outer circumferential surface. The jaw portion 12 has the shape of a mountain extending along the circumference of the duct 11, which forms an undercut.

FIG. 2 is a cross-sectional view of a prior art mold 10 capable of injection molding the radiator tank of FIG. 1.

Referring to the drawings, the hollow portion 22 is formed in the first mold portion 21 of the injection mold 20, the jaw portion 12 shown in Figure 1, that is, on the inner peripheral surface of the hollow portion 22, The cavity 23 of the same shape as the outer peripheral surface of the duct 10 in which the undercut was formed is formed. The core 25 is inserted into the hollow part 22 of the first mold part 21 to define the cavity 23 having the same shape as the injection tube 10, wherein the core 25 is the hollow part. It is fixed to the slider 26 which slides in the longitudinal direction of 22. As shown in FIG. A guide groove 27 is formed in the first mold part 21 in a direction parallel to the moving direction of the slider 26, and a split pin 28 is slidably installed in the guide groove 27. In the end of the 28 and the guide groove, a locking jaw 28a and a stepped jaw 27a on which the locking jaw 28a is engaged are formed. An inclined groove 26a is formed at an end of the slider 26, and an inclined pin 29 is installed in the inclined groove 26a to be slidable in the vertical direction.

To mold the duct 11 of the tank 10 using the conventional injection mold configured as described above is subjected to the following process.

The molten molding material is injected into the cavity 23 while the core 25 is inserted into the hollow part 22 to form the cavity 23. After the time when the solidification is completed, if the inclined pin 29 rises vertically, the slider 26 is retracted and the core 25 installed thereon is separated from the molded injection tube 10. At this point, the locking jaw 28a of the split pin 28 is coupled to the jaw 27a of the guide groove 27 to move the first mold 21 to complete the duct from the first mold 21. 11, Fig. 1).

The injection mold of the prior art described above has the following problems. First, when the first mold and the molded injection tube are separated, the undercut portion, that is, the circumferential jaw portion is not supported, so that stress is applied to the circumferential jaw portion when the first mold is separated, thereby causing a phenomenon in which the shape of the duct is distorted. do. Next, when the first mold is separated, the injection tube in which the first mold is formed by the transfer force is crushed. It is also possible that the base of the duct breaks when the mold is separated.

The present invention has been made to solve the above problems, an object of the present invention to provide a mold for injection molding that can be applied to the product formed undercut.

Another object of the present invention is to provide a mold for injection molding that can provide an accurate appearance without damaging the appearance of the undercut formed product.

1 is a perspective view showing a tank portion of an automobile radiator;

2 is a partial cross-sectional view of a mold for injection molding according to the prior art.

3 is a partial cross-sectional view of a mold for injection molding according to the present invention.

Brief description of the main parts of the drawing

11.duct 12.chin part

31. First Block 32. Second Block

33.Core 34.Flange

36.Rod 37.Spring

38. Bolt 39. Cavity

In order to achieve the above object, according to the present invention, a first block member having a hollow portion integrally fastened with a flange, a second block member having a hollow portion with upper and lower flange counterparts to which the flange can correspond, A rod member inserted into a hole formed in the flange and fixed between the upper and lower flange counterparts to guide the flange, an elastic member disposed between an upper surface of the flange and a bottom face of the upper flange counterpart, and the first member An injection molding die is provided that includes a block member and a core member that can be inserted into a hollow portion of a second block member.

According to one feature of the invention, the hollow portion of the second block member is formed with a recess having an inner diameter larger than the inner diameter of the hollow portion.

Hereinafter, the present invention will be described in more detail with reference to an embodiment shown in the accompanying drawings.

3 is a cross-sectional view of a part of the injection molding die according to the present invention, which shows a part of the upper mold as for forming the tank for the radiator shown in FIG.

Referring to the drawings, the upper mold 30 of the injection molding die is formed of a first block 31 to which the flange 34 is fastened and a flange corresponding surface 35a and 35b corresponding to the flange 34. 2 blocks 32 and the core 33 is included.

The first block 31 is fastened through the flange 34 and the bolt 38. A through hole is formed in the flange 34, and the rod 36 is inserted through the through hole. When the first block 31 moves up and down in FIG. 3, the flange 34 is guided along the rod 36. The hollow part 31a is formed in the center part in the 1st block 31, and the core 33 is inserted in the hollow part 31a.

The hollow part 32a is formed in the 2nd block 32 inside. The hollow part 32a of the second block 32 may be disposed in line with the hollow part 31a of the first block 31 so that the core 33 may be inserted through the hollow parts 31a and 32a. . When the core 33 is inserted into the second block 32, the cavity 39 is formed. The cavity 39 is formed with a recess 39a in which the jaw portion 12 of FIG. 1 is formed therein. The inner diameter of the concave portion 39a is larger than the inner diameter of the hollow portion 32a of the second block 32. In the injection molding operation, a molding material is injected into the cavity 39, and when the material solidifies in the cavity 39, it has the shape of the duct 11 shown in FIG. 1.

Upper and lower flange counterparts 35a and 35b are formed in the second block 32. The upper and lower flange counterparts 35a and 35b are the portions to which the flange 34 corresponds when the first block 31 moves up and down. The rod 36 is fitted to the upper and lower flange counterparts 35a and 35b, and a spring 37 is inserted into the rod 36 on the outer circumferential surface between the upper flange counterpart 35a and the flange 34. It is published in a state. Accordingly, in the state where no external force is applied, the bottom face of the flange 34 of the first block 31 and the top face of the flange counterpart 35b of the second block 32 are in contact with each other.

Hereinafter, the injection operation using the injection molding die according to the present invention will be described.

The injection and solidification process of the molding material in the injection molding operation is carried out in the mold state as shown in FIG. That is, the bottom of the flange 34 of the first block 31 is in contact with the upper surface of the flange counterpart 35b of the second block 32 by the pressure of the spring 37, and the core 33 is the second block. It inserts in the state which forms the cavity 39 of a predetermined shape in the hollow part 32a of (32). The operator injects molding material into the cavity 39 through an inlet not shown, and after a predetermined time solidification will occur to form a tank including a duct 11 similar to that shown in FIG.

When solidification is completed, the removal process of the first and second blocks 31 and 32 and the core 33 should be performed. First, the first block 31 and the core 33 may be removed at the same time by being interconnected with each other. The first block 31 and the core 33 are removed by moving upward in the figure. At this time, the second block 32 cannot move unless the core 33 rises by a predetermined distance. This is because the molding material solidified in the recess 39a of the cavity 39 prevents the rise of the second block 32. That is, while the core 33 remains inside the duct (11 in FIG. 1) formed in the cavity 39, the jaw portion (12 in FIG. 1) formed in the recess 39a cannot be deformed and deformed. The second block 32 cannot rise because the recess 39a is caught by the jaw portion 12 of the duct 11. Thus, the flange 34 of the first block 31 rises while compressing and deforming the spring 37.

When the end of the core 33 completely exits the cavity 39, that is, when the core 33 is completely removed from the interior of the duct (11 in FIG. 1), the jaw portion 12 of the duct 11 is subject to shrinkage deformation. It is possible. The force of the spring 37 compressed by the flange 34 of the first block 31 forces the second block 32 to rise, with the duct 11 formed in the recess 39a of the cavity 39. When the jaw portion 12 of the) is contracted, the second block 32 is also removed by raising.

The injection molding die according to the present invention can be widely applied to a product in which an undercut is formed, and is very effective because the molding operation can be performed without damaging the undercut portion. In addition, even if the operator does not pay special attention to each mold block can be removed at the appropriate time in sequence has the advantage of improved work productivity.

Although the present invention has been described with reference to one embodiment shown in the accompanying drawings, it is only an example, it will be understood by those skilled in the art that various embodiments are possible. Therefore, the true scope of protection of the present invention should be defined by the appended claims.

Claims (2)

A first block member having a flange fastened integrally and having a hollow portion, A second block member having a hollow portion having upper and lower flange counterparts corresponding to the flange, A rod member inserted between a hole formed in the flange and fixed between the upper and lower flange counterparts to guide the flange; An elastic member disposed between an upper surface of the flange and a lower surface of the upper flange counterpart; Injection mold comprising a core member that can be inserted into the hollow portion of the first block member and the second block member. The injection molding die according to claim 1, wherein the hollow part of the second block member is formed with a recess having an inner diameter larger than that of the hollow part.