Injection mould

Abstract

To provide injection molding which enables molding of high quality molded products without causing deformation, such as frayed spot, by allowing mold parts to follow the shrinkage of the resin.SOLUTION: An injection mold for injection molding resin, consisting of a fixed side mold and a movable side mold, the molding section is formed by the fixed side cores 1 of the fixed side mold, the movable side cores 2 and the slide core 3 of the movable side mold, and the slide core 3 can move following the resin shrinkage. The slide core holder is divided into two parts, and when the mold is opened, the slide core 3 is lifted by the force of the coil spring 7 installed between the two parts of the slide core holders 4 and 5 to follow the resin shrinkage of the molded product 8, thereby preventing deformation of the molded product such as frayed spot.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an injection molding die capable of suppressing deformation such as curling that occurs during mold release. [Background technology]

[0002] In resin molding using an injection mold, high-temperature molten resin is poured into the mold and cooled to solidify the resin. During this process, the resin shrinks and bites into the mold, and if the resistance is large, deformation such as curling occurs when the product is released from the mold. To prevent this, a draft angle is provided to make the product easier to release from the mold, but if the product is relatively large, the amount of shrinkage of the resin also increases, and the draft angle alone is not enough to reduce the resistance to release from the mold, resulting in deformation of the product such as curling.

[0003] Patent Document 1 discloses an example of a mold having a draft angle to make it easier to release a product from the mold. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2007-98698 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, in injection molding, the resin may stick to the mold due to shrinkage, and the molded product may be deformed, such as curled, when released from the mold.

[0006] An object of the present invention is to provide an injection molding mold that allows the mold parts to follow the shrinkage of resin, thereby making it possible to produce high-quality molded products without causing deformation such as curling. [Means for solving the problem]

[0007] To achieve the above object, an example of the "injection molding die" of the present invention is as follows: An injection molding die that is composed of a fixed die and a movable die and that injects resin, a fixed insert of the fixed die, and a movable insert and a slide core of the movable die form a molding part; A slide core holder divided into two parts is provided on the outside of the slide core, A first slide core holder is joined to the slide core, a second slide core holder is fixed to a movable mold, a shoulder bolt is inserted into the first slide core holder to fix the first slide core holder movably relative to the second slide core holder, a coil spring is inserted into the shoulder bolt between the first slide core holder and the second slide core holder, and the first slide core holder is pressed in the resin contraction direction by the coil spring, and when the mold is opened, The slide core Molded products Moves according to resin shrinkage to make . The slide core is fixed when the mold is closed and moves in the direction of resin contraction when the mold is opened, thereby reducing the biting resistance caused by resin contraction and preventing deformation such as curling. Effect of the Invention

[0008] According to the present invention, it is possible to provide an injection molding die that allows the mold parts to follow the shrinkage of the resin, thereby making it possible to mold high-quality molded products without causing deformation such as curling.

[0009] Problems, configurations and effects other than those described above will become apparent from the following description of the embodiments. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a cross-sectional view of a mold structure in a closed state according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view of a mold structure in a state in the middle of mold opening according to an embodiment of the present invention. [Diagram 3] FIG. 2 is a cross-sectional view of the mold structure in the embodiment of the present invention when the mold is opened. [Figure 4] FIG. 2 is an enlarged view of the vicinity of a slide block in the mold closed state of FIG. [Diagram 5] FIG. 3 is an enlarged view of the vicinity of the slide block in the middle of mold opening in FIG. 2. [Figure 6] FIG. 1 is a diagram showing an example of a molded product. [Figure 7] FIG. 1 is a cross-sectional view of a conventional mold structure in a closed state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Prior to describing the embodiments of the present invention, an injection molding die on which the present invention is based will be described.

[0012] An example of a molded product formed using an injection mold is shown in Fig. 6. The molded product 8 is box-shaped and has a hole or recess 80 on one side.

[0013] Fig. 7 is a schematic cross-sectional view of a conventional injection molding die for molding the molded product shown in Fig. 6. The figure shows the die in a closed state.

[0014] The injection molding die is composed of a fixed side 100 and a movable side 200 that moves relative to the fixed side. The components of the fixed side 100 of the die body include a fixed side mounting plate 11 that is connected to the fixed side of the injection molding device. A fixed side mold plate 12 is attached to the fixed side mounting plate 11, and the fixed side mold plate 12 is also provided with a sprue bushing 19, which is a part that guides the molten resin injected from the injection nozzle of the injection molding device to the molding part in the die. The fixed side mold plate 12 is also equipped with a locking block 14 that pushes out a slide block 17 attached to the movable side 200 of the die body when the die is closed, and an angular pin 13 that moves the slide block 17 to the outside of the die when the die is opened.

[0015] The components of the mold body movable side 200 include a movable side attachment plate 15 that is connected to the movable side of the injection molding device, and a movable side mold plate 16 that is attached to it. The movable side mold plate 16 is equipped with a slide block 17 that slides as the movable side 200 moves. In the figure, reference numeral 18 denotes an angular pin insertion hole through which the angular pin 13 passes.

[0016] The fixed insert 1 on the fixed mold plate 12, the movable insert 2 on the movable mold plate 16, and the slide core 3 on the slide block 17 form a molded part, and with the mold closed, high-temperature molten resin is poured in through the sprue bushing 19 and cooled and solidified to form the molded product 8. During this process, the resin contracts and sticks to the mold, causing deformation such as curling when the mold is released, particularly in the holes or recesses 80.

[0017] The present invention solves this problem by allowing mold parts to follow the shrinkage of resin, making it possible to provide high-quality molded products without the occurrence of deformations such as curling.

[0018] Hereinafter, the embodiments of the present invention will be described with reference to the drawings. However, the present invention should not be interpreted as being limited to the description of the embodiments shown below. It will be easily understood by those skilled in the art that the specific configuration can be changed without departing from the spirit or gist of the present invention. EXAMPLES

[0019] Fig. 1 shows a cross-sectional view of the mold structure in a mold closed state according to an embodiment of the present invention. Fig. 2 shows a cross-sectional view of the mold structure in the middle of mold opening, with the movable side 200 moved slightly downward. Fig. 3 shows a cross-sectional view of the mold structure in the finished mold opening state, with the movable side 200 moved further downward.

[0020] As in Fig. 7, the injection molding die is composed of a fixed side 100 and a movable side 200 that moves relative to the fixed side. The components of the fixed side 100 of the die body include a fixed side mounting plate 11 that is connected to the fixed side of the injection molding device. A fixed side mold plate 12 is attached to the fixed side mounting plate 11, and the fixed side mold plate 12 is also provided with a sprue bushing 19, which is a part that guides the molten resin injected from the injection nozzle of the injection molding device to the molding part in the die. The fixed side mold plate 12 is also equipped with a locking block 14 that pushes the slide block 17 attached to the movable side 200 of the die body toward the center when the die is closed, and an angular pin 13 that moves the slide block 17 to the outside of the die when the die is opened.

[0021] The components of the mold body movable side 200 include a movable side attachment plate 15 connected to the movable side of the injection molding device, a movable side mold plate 16 attached to the movable side attachment plate 15, and an ejector pin (not shown) that ejects the molded part. The movable side mold plate 16 is equipped with a slide block 17 that slides left and right as the movable side 200 moves. In the figure, reference numeral 18 denotes an angular pin insertion hole through which the angular pin 13 passes.

[0022] The operation of the mold shown in FIGS. 1 to 3 will be outlined below. In the mold open state shown in FIG. 3, when the movable side 200 is moved upward toward the fixed side 100, the slide block 17 slides toward the center while being guided by the angular pin 13, as shown in FIG. 2. Then, the locking block 14 The inclined surface and slide Block 17 The inclined surfaces of the locking block 14 come into contact with each other, and the slide block 17 is pressed toward the center by the inclined surfaces of the locking block 14. Then, the movable-side insert 2 attached to the movable-side mold plate 16, the slide cores 3 on both sides of the movable-side insert 2, and the fixed-side insert 1 of the fixed-side mold plate 12 form a molding part. In the mold closed state shown in FIG. 1, molten resin is introduced into the molding portion in the mold from the sprue bushing 19 and allowed to solidify. After the molten resin has solidified, the movable side 200 is moved downward away from the fixed side 100, as shown in Fig. 2 and Fig. 3. The slide block 17 moves guided by the angular pin 13, and the slide core 3 opens. Then, the molded product 8 on the movable side 200 is pushed out and removed.

[0023] Next, the characteristic configuration of the resin molding die of this embodiment will be described. Fig. 4 shows an enlarged view of the right slide block 17 and its vicinity in the mold closed state of Fig. 1. Fig. 5 shows an enlarged view of the right slide block 17 and its vicinity in the mold open state of Fig. 2.

[0024] The fixed insert 1 of the fixed mold plate 12, the movable insert 2 attached to the movable mold plate 16, and the slide core 3 of the slide block 17 form a molding section (mold) for molding the molded product 8. The outside of the slide core 3 has a slide core holder a (first slide core holder) 4 and a slide core holder b (second slide core holder) 5, which are divided into two parts, upper and lower. The slide core 3 is connected to the slide core holder a4 by a bolt (not shown). The slide core holder a4 located at the top is connected to the slide core holder b5 by a shoulder bolt 6 so as to be movable by a gap of 9. A coil spring 7 is inserted into the shoulder bolt 6, which pushes the slide core holder a4 upward in a direction away from the slide core holder b5. The head of the shoulder bolt 6 acts as a stopper and regulates the upper position of the slide core holder a4. That is, the shoulder bolt 6 and the coil spring 7 act to move the slide core holder a4 away from the slide core holder b5 by a gap of 9.

[0025] When the mold is closed to pour the molten resin into the mold as shown in Fig. 4, the fixed part presses the slide core 3 and slide core holder a4 from above, so the coil spring 7 is bent and the slide core holder a4 and slide core holder b5 are in a mated state. In this state, the molten resin is poured into the molding part. When the mold is opened after the molten resin has solidified, as shown in Fig. 5, The movable side moves downwards, The slide core 3 and the slide core holder a4 are released from the fixed part. Then, the slide core 3 and the slide core holder a4 connected by the bolt are pulled by the force of the coil spring 7 between the slide core holder a4 and the shoulder bolt 6. Head When the molten resin cools and solidifies, a force acts upward in the direction of resin contraction, as shown in the figure. Relative to the movable mold plate 16By lifting up, the molded product 8 shrinks, reducing the mold release resistance caused by the resin sticking to the mold, and deformation such as curling can be prevented. In particular, deformation such as curling can be prevented in holes and recesses 80 in a direction intersecting the resin shrinkage direction.

[0026] According to the injection molding die of this embodiment, the slide core 3 forming the molding portion (mold) is made movable in response to the resin contraction, and the slide core 3, which is a die part, is made to follow the resin contraction when the die is opened, thereby making it possible to provide a high-quality molded product without causing deformation such as curling. [Explanation of symbols]

[0027] 1…Fixed side insert 2…Movable side insert 3...Slide core 4…Slide core holder a 5...Slide core holder b 6…Shoulder bolt 7…Coil spring 8...Molded products, 9...Stroke amount (gap) by which the slide core rises 11...Fixed side mounting plate 12…Fixed side template 13. Angulapin 14…Locking block 15...Movable side mounting plate 16…Movable side template 17…Slide block 18...Angular pin insertion hole 80...Hole or recess in molded product 100…Mold body fixed side 200…Mold body movable side

Claims

1. An injection molding die for injecting resin, comprising a fixed die and a movable die, a fixed insert of the fixed die, and a movable insert and a slide core of the movable die form a molding part; A slide core holder divided into two parts is provided on the outside of the slide core, an injection molding die comprising: a first slide core holder coupled to the slide core; a second slide core holder fixed to a movable die; a shoulder bolt inserted into the first slide core holder to fix the first slide core holder movably relative to the second slide core holder; a coil spring inserted into the shoulder bolt between the first slide core holder and the second slide core holder; the coil spring pressing the first slide core holder in the direction of resin contraction; and a slide core moved in response to resin contraction of a molded product when the die is opened.

2. 2. The injection mold according to claim 1, The head of the shoulder bolt restricts the movement of the first slide core holder.

3. 2. The injection mold according to claim 1, An injection molding die in which the slide core and the first slide core holder are pressed by the fixed-side die when the die is closed, and the pressure by the fixed-side die is released when the die is opened, so that the slide core follows the resin contraction.

4. 2. The injection mold according to claim 1, The molded product is an injection molding die having a hole or a recess on the side surface.

Images