JP2006248055A - Two stage ejection mechanism of injection molding mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smooth the action of an ejector pin in a two stage ejection mechanism. <P>SOLUTION: A compression coil spring 26 biasing an ejector plate B over 19 and an ejector plate A under 17 to press each other is fitted into a guide pin 25 set on the ejector plate A under 17 holding an ejector pin A14 penetrating an ejector plate B under 20 and the ejector plate B over 19 which hold an ejector pin B15. The ejector pin B15 is moved vertically in the clearance d1 between a stopper pin 27 which is bolted on the ejector plate B over 19 and set to penetrate the ejector plate A under 17 and an ejector plate A over 16 and a movable side backing plate 13. The ejector pin A14 is moved vertically in the clearance d2 between the ejector plate A over 16 and the movable side backing plate 13. An ejector rod 28 penetrates the ejector plates B over 19 and B under 20 and is fixed to the middle of the bottom surface of the ejector plate A under 17. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an injection mold, and more particularly to a two-stage ejecting mechanism of an ejector.

  In recent years, plastic molded products have been frequently used in various industrial molded products for the purpose of improving material properties, facilitating parts production, facilitating assembly, reducing weight, and reducing costs, and are mass-produced using injection molding machines. . Some injection molds for molding such plastic molded products use a two-stage extrusion mechanism (see, for example, Patent Document 1). The injection mold disclosed in Patent Document 1 has two drive mechanisms for driving the first ejector pin drive plate and the second ejector pin drive plate, and each drive mechanism is driven separately. Then, after ejecting the first ejector pin, the second ejector pin is ejected. On the other hand, what is shown in FIG. 4 is an injection mold having another conventional two-stage extrusion mechanism. FIG. 4 is a cross-sectional view of the main part of a movable mold showing a conventional injection mold.

  First, the configuration of this injection mold will be described. In FIG. 4, reference numeral 50 denotes a movable side mold constituting an injection mold, and the fixed side mold is omitted. Only main components are shown in the movable mold 50. Reference numeral 51 denotes a movable side mounting plate attached to the movable side of the injection molding machine, 52 denotes a spacer block, 53 denotes a movable side receiving plate, and the movable mold 50 is formed by laminating and fixing them. . Reference numeral 54 denotes one ejector pin A for projecting a molded product from a movable side mold plate (not shown) located on the movable side receiving plate 53, and 55 denotes the other ejector pin B.

  Reference numerals 56 and 57 denote an ejector plate A and an ejector plate A below which sandwich the large diameter bottom portion of the ejector pin A54. 58 and 59 indicate on the ejector plate B and below the ejector plate B that hold the large diameter bottom portion of the ejector pin B55. The ejector plate A upper 56 and the ejector plate A lower 57 and the ejector plate B upper 58 and the ejector plate B lower 59 move up and down between the movable mounting plate 51 and the movable receiving plate 53.

  Reference numeral 61 denotes a stopper pin standing on the ejector plate B 58 and penetrating the ejector plate A upper 56 and A lower 57. Reference numeral 62 denotes an ejector rod which is erected at the central portion of the lower 57 of the ejector plate A and penetrates the upper 58 of the ejector plate B and the lower 59 of B. 64 is an ejector rod of an injection molding machine which pushes up the ejector rod 62. Show. Reference numeral 65 denotes a best lock which is one of the best locks fixed to the lower 57 of the ejector plate A. Reference numeral 66 denotes a lower part of the best lock which is the other of the best locks fixed to the upper 58 of the ejector plate B. . As shown in FIG. 5, the best lock includes a pair of claws biased to be closed by a leaf spring on the top of the best lock 65, and a pair of rods (not shown) that engage with the claws on the bottom of the best lock 66. Yes. Both are connected when they abut against each other and are separated when a certain pulling force is applied.

  Next, the operation of this injection mold will be described. The injection mold is attached to an injection molding machine and heated, and after the mold is clamped, molten resin is injected from a resin injection port. Resin fills the cavity from the gate. While the pressure is maintained for a certain time, the resin is cooled and cured. Next, the fixed mold and the movable mold 50 are opened from the parting line, and the ejector plate A upper 56 and A lower 57 are raised in accordance with the operation of the ejector rod 64. At this time, the ejector plate B upper 58 and B lower 59 connected by the best lock upper 65 and the lower 66 are also raised simultaneously. In this way, the ejector pin A54 and the ejector pin B55 are protruded (first-stage protrusion).

When the protruding amount reaches a certain level, the stopper pin 61 comes into contact with the movable side receiving plate 53, so that the ejector plate B upper 58 and B lower 59 are stopped. Thereafter, when the ejector rod 64 is further protruded, the best lock lower 66 stays on the ejector plate B 58 together with the ejector plate B upper 58, and the best lock upper 65 away from the best lock lower 66 is the ejector plates A upper 56 and A lower. Further rise with 57 and ejector pin A54 is projected. (Second-stage protrusion). After mold release, the mold closes and returns to the original position in preparation for the next molding. The best lock upper 65 and lower 66 are also connected again. As described above, this injection mold is configured to drive the ejector pin A14 and the ejector pin B15 in two stages by driving the ejector plate A and the ejector plate B by one drive mechanism.
JP 2000-102955 A (page 4, FIGS. 1 to 5)

  However, as described above, in such a conventional two-stage extrusion mechanism of an injection mold, the upper connection of the ejector plate B 58 and the lower ejector plate A 57 are separated by the magnet or best lock upper 65 and lower 66. It was. In such a mechanism, when the ejector plates A and B are separated or connected, the impact is large, and this tends to cause a mold release failure such as a push-up failure or deformation of the molded product. In addition, when the upper and lower best locks 65 and 66 are opened and closed, the horizontal balance of the ejector plates A 56 and 57 57 tends to be inclined, and the parts such as the ejector pins, cavities, and cores are unevenly worn. It was.

  The present invention has been made to solve such a conventional problem, and an object of the invention is to provide an injection mold capable of reducing the impact and smoothly operating in the two-stage ejection mechanism. That is.

  Means of the present invention for solving the above-mentioned problem includes a first ejector pin held by a first ejector plate and a second ejector pin held by a second ejector plate, and the first ejector pin. In the injection mold configured to drive the plate and the second ejector plate by a single drive mechanism to operate the first ejector pin and the second ejector pin in two stages, the first mold A coil spring that urges the first ejector plate and the second ejector plate to be pressed against each other is inserted into a guide pin that is erected on the ejector plate and penetrates the second ejector plate. It is characterized by that.

  Further, the stroke of the second ejector pin is regulated by a stopper pin standing on the second ejector plate.

  According to this invention, it has the 1st ejector pin hold | maintained at the 1st ejector plate hold | maintained at the 1st ejector plate, and the 2nd ejector pin hold | maintained at the 2nd ejector plate, Said 1st In the injection mold configured to drive the first ejector pin and the second ejector pin in two stages by driving the ejector plate and the second ejector plate by a single drive mechanism. A coil spring that is erected so as to press the first ejector plate and the second ejector plate against each other is inserted into a guide pin that is erected on one ejector plate and penetrates the second ejector plate. So that both ejector pins can be operated smoothly. It turned so that it was possible to reduce the uneven wear of the ejector pin and cabinet parts.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part showing an injection mold according to an embodiment of the present invention. First, the configuration of this mold will be described. In FIG. 1, the fixed side mold constituting the injection mold is omitted. Reference numeral 10 denotes a movable side mold, 11 denotes a movable side mounting plate, and 13 denotes a movable side receiving plate. A spacer block (not shown) is disposed between the movable side mounting plate 11 and the movable side receiving plate 13. Reference numeral 14 denotes an ejector pin A which is a first ejector pin, and reference numeral 15 denotes an ejector pin B which is a second ejector pin.

  Reference numerals 16 and 17 denote the upper and lower sides of the ejector plate A, which is the first ejector plate that holds the large-diameter bottom portion of the ejector pin A14, and 18 denotes a bolt screwing the two plates together. Reference numerals 19 and 20 indicate the upper and lower portions of the ejector plate B, which is a second ejector plate that holds the large-diameter bottom portion of the ejector pin B15, and 21 indicates a bolt that is screwed together. All of these plates move up and down between the movable mounting plate 11 and the movable receiving plate 13.

  Reference numeral 25 denotes an ejector plate B upper 19 and B lower 20, and a guide pin which is erected by being screwed to the ejector plate A lower 17. 26 is inserted into the guide pin 25 and is inserted into the ejector plate B upper 19 And a compression coil spring that urges the ejector plate A lower 17 and the ejector plate B lower 20 to press each other through the ejector plate B lower 20. Reference numeral 27 denotes a stopper pin that is bolted to the upper 19 of the ejector plate B and is erected through the upper 16 of the ejector plate A and the lower 17 of the A.

  The stroke of the ejector pin B15 is regulated so as to move up and down within the gap d1 between the stopper pin 27 and the movable side receiving plate 13. The ejector pin A14 moves up and down within a gap d2 between the ejector plate A 16 and the movable side receiving plate 13. Reference numeral 28 denotes an ejector rod which passes through the upper 19 and lower 20 of the ejector plate B and is fixed to the center of the bottom surface of the lower 17 of the ejector plate A with 30 bolts. Reference numeral 29 denotes an ejector rod of an injection molding machine.

  Next, the operation of this injection mold will be described. 2 and 3 are cross-sectional views showing the operation of injection molding. The molten resin is cooled and cured after being poured into the mold. Next, the mold is opened, and as shown in FIG. 2, the lower plate 17 of the ejector plate A is pushed up according to the operation of the ejector rod 29 in the movable mold 10. At this time, the ejector plate B upper 19 and B lower 20 and the ejector plate A upper 16 and A lower 17 integrated together are pushed up until the stopper pin 27 contacts the movable side receiving plate 13. Along with this, the ejector pins A14 and B15 are protruded by the stroke d1 (first-stage protrusion).

  Thereafter, as shown in FIG. 3, the lower ejector plate A 17 is further pushed up according to the operation of the ejector rod 29. At this time, since the upper movement of the ejector plate B 19 is restricted by the stopper pin 27, the lower ejector plate A 17 and the upper A 16 move away from the upper ejector plate B 19, and the coil spring 26 is compressed. When the upper 16 of the ejector plate A further rises, it eventually comes into contact with the movable side receiving plate 13 and stops. Along with this, the ejector pin A14 is pushed up by d2 (second stage protrusion). After the molded product is released, each ejector plate is returned to its original position by the action of the coil spring 26 when the mold is closed in preparation for the next molding.

  Next, effects of the embodiment of the present invention will be described. When the first half of the ejector rod 29 is raised, the ejector pins A14 and B15 are simultaneously pushed up by the stroke d1, and when the latter half is raised, the ejector pin B14 is continuously pushed up and pushed up by the stroke d2 while the ejector pin B15 is stopped there. Can do. During this time, the connection and separation between the ejector plate A upper 16 and lower A 17 and the ejector plate B upper 19 and lower B 20 can be smoothly performed without impact, so that uneven wear of the ejector pins and the cavity parts can be reduced.

  The two-stage ejection mechanism of the present invention can be used, for example, as a mechanism in which an injection mold having a slide core opens a slide core by a first push-up and releases a molded product by a second push-up, etc. It can be widely applied to injection molds that require a two-stage extrusion mechanism.

It is principal part sectional drawing which shows the injection mold which is embodiment of this invention. It is principal part sectional drawing which shows the operation | movement of the injection mold which is embodiment of this invention. It is principal part sectional drawing which shows the operation | movement of the injection mold which is embodiment of this invention. It is principal part sectional drawing which shows the conventional injection molding die. It is a front view which shows the best lock | rock operation | movement of the conventional injection molding die.

Explanation of symbols

10 Injection mold.
14 Ejector pin A
15 Ejector pin B
16 Upper ejector plate A 17 Lower ejector plate A 19 Upper ejector plate B 20 Lower ejector plate B 25 Guide pin 26 Coil spring 27 Stopper pin

Claims (2)

  A first ejector pin held by the first ejector plate and a second ejector pin held by the second ejector plate, wherein the first ejector plate and the second ejector plate are driven together; In an injection mold configured to be driven by a mechanism to operate the first ejector pin and the second ejector pin in two stages, the second ejector plate is erected on the first ejector plate. An injection mold, wherein a coil spring that urges the first ejector plate and the second ejector plate to press each other is fitted into a guide pin that passes through the guide pin. 2. The injection mold according to claim 1, wherein a stroke of the second ejector pin is regulated by a stopper pin standing on the second ejector plate.

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