JP2008030248A - Injection mold and molding molded using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve the miniaturization of an injection mold though equipped with a guide pin for ensuring precision. <P>SOLUTION: This injection mold is constituted so that support pins 8 are inserted in paired templates 3 and 4 in a freely slidable manner. The respective templates 3 and 4 are respectively equipped with guide bushes 13 and 14 at the insertion parts of the support pins 8 and the guide bush 13 of one template is equipped with the cylindrical guide pin part 9 protruded toward the other template, while the guide bush 14 of the other template has an inner diameter receiving the cylindrical guide pin part 9 in a freely slidable manner. The function of guide pins is provided in the guide bushes receiving the support pins in a freely slidable manner. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a mold used for injection molding, in particular, a mold used for molding an ultra-small molded product, and a molded product molded using the same.

  In the mold for injection molding, especially in the sleep rate structure comprising a runner stripper plate, a fixed side mold plate and a movable side mold plate, a support pin is slidably inserted into these to provide a guide for opening and closing the mold. A guide bush is provided on one of the two mold plates and the guide pin is slidably received in the other mold plate for accurate positioning between the fixed mold plate and the movable mold plate. Provided.

  By the way, what is to be molded is a fine size such as 0.9 mm × 1.5 mm × 0.5 mm for a micro relay, and if it is to be formed outsert (or insert), compact size (for example, 150 mm × 130 mm) ), But the ratio of the support pin and guide pin installation space becomes very large, and the mold cannot be downsized.

  By using the support pin as a guide pin, the guide pin can be omitted, but the support pin is inserted into the fixed side mounting plate, the runner stripper plate, the fixed side template, and the movable side template. Because of this, the shaft length is long and it is easy to bend, and if any of the above four causes distortion or extension, tilt will occur, and this ensures the positioning accuracy of both the above-mentioned fine mold plates The problem that it cannot be performed and the problem that the mold cannot be opened and closed smoothly occur, and stable mass production of precision fine parts cannot be performed.

In terms of downsizing, Japanese Patent Application Laid-Open No. 2001-121579 discloses a support pin that also serves as a puller bolt. However, this does not solve the above-described problem regarding the guide pin.
JP 2001-121579 A

  The present invention has been invented in view of the above-described conventional problems, and an object thereof is to provide an injection mold that can be reduced in size while being provided with a guide pin for ensuring accuracy. In addition, it is an object of the present invention to provide a highly accurate molded product obtained by molding using the above mold.

  In order to solve the above problems, an injection mold according to the present invention is such that a support pin is slidably inserted into a pair of mold plates, and each mold plate is guided to an insertion portion of the support pin. Each of the bushes includes a cylindrical guide pin portion that protrudes toward the other template plate, and the guide bush in the other template plate slidably receives the cylindrical guide pin portion. It is characterized by an inner diameter. A guide bush having a support pin slidably provided with a guide pin function.

  At this time, the guide bush provided with the cylindrical guide pin portion provided on one mold plate is axially fixed to the one mold plate by a snap ring attached to a groove formed on the outer peripheral surface. In this case, it is possible to easily prevent the guide bush that also serves as the guide pin from coming off.

  Further, when at least one of the cylindrical guide pin portion and the guide bush that slidably receives the cylindrical guide pin portion is provided with a tapered surface for guiding each other, smooth guide can be performed. In particular, the latter guide bushing is effective when the cylindrical guide pin portion has a small diameter.

  The guide bush provided with the cylindrical guide pin portion is disposed on the fixed-side template, and is slidably inserted into the guide bush and has one end protruding from the distal end surface of the cylindrical guide pin portion. The support pin may have an outer diameter collar attached to the one end that is larger than the inner diameter of the cylindrical guide pin portion and smaller than the inner diameter of the guide bush arranged on the movable template. Good. The presence of the collar allows the support pin to function as a puller bolt.

  Further, when the collar is provided with a tapered surface for guiding the guide bush arranged on the movable template, smooth guide can be performed even if the cylindrical guide pin portion is not provided with a tapered surface. Can do.

  Furthermore, when the three-dimensional molded product having a fine size with a side of several mm or less is formed, downsizing by the support pin guide bush also serving as the guide pin becomes more effective.

  The molded product according to the present invention is characterized in that it is molded using the above-described injection mold and has a three-dimensional shape with a minute size of one side or less.

  The injection mold according to the present invention does not require a space for arranging the guide pin separately because the guide bush having the support pin slidably receives the function of the guide pin. In addition, since the positioning by the guide pin can be performed, there is no problem in molding a precision fine part, and for this reason, both accuracy ensuring and miniaturization can be achieved.

  In addition, the molded product according to the present invention has a high precision because it has a fine size of 2 mm or less, but has a high matching accuracy between the cavity side mold and the core side mold.

  Hereinafter, the present invention will be described with reference to an embodiment shown in the accompanying drawings. FIG. 1 shows an injection mold for forming a fine molded product having a sleep rate structure according to the present invention. , Runner stripper plate 2, stationary side mold plate (cavity side mold) 3, movable side mold plate (core side mold) 4, receiving plate 5, spacer block 6, movable side mounting plate 7 are arranged in order. The mold includes a support pin 8 that is slidably inserted into the fixed side mounting plate 1, the runner stripper plate 2, the fixed side mold plate 3, and the movable side mold plate 4. In the figure, S indicates a molded product, and R indicates a runner.

  Guide bushes 12, 13, and 14 are provided in the insertion portions of the support pins 8 in the runner stripper plate 2, the fixed side mold plate 3, and the movable side mold plate 4, respectively. The guide bush 13 provided on the fixed side mold plate 3 is integrally provided with a cylindrical guide pin portion 9 protruding toward the movable side mold plate 4. The guide bush 14 provided on the movable side mold plate 4 has an inner diameter that slidably receives the cylindrical guide pin portion 9.

  Further, as shown in FIG. 2, the guide bush 13 is axially arranged with respect to the fixed-side template 3 by a flange 21 on one end side and a snap ring 23 attached to a groove 22 formed on the outer peripheral surface. Are fixed, and a tapered surface 24 for guiding is formed on the outer peripheral surface of the distal end of the cylindrical guide pin portion 9.

  For this reason, when the mold is clamped, the cylindrical guide pin portion 9 in the guide bush 13 fixed to the fixed side mold plate 3 is fitted into the guide bush 14 of the movable side mold plate 4 as shown in FIG. Both mold plates 3 and 4 are positioned. In addition, since the guide bush 13 that slidably supports the support pin 8 has a positioning function, there is no need to provide a space in the mold as in the case of providing a separate guide pin. The size of the mold can be reduced.

  Here, a collar 32 is attached to the tip of the support pin 8 by a bolt 31. The collar 32 having an outer diameter that is larger than the inner diameter of the cylindrical guide pin portion 9 and smaller than the inner diameter of the guide bush 14 of the movable side plate 4 and less than or equal to the minimum diameter of the tapered surface 24 of the cylindrical guide pin portion 9. Functions as a member for determining the mold opening amount when the mold is opened. The support pin 8 can be provided with the collar 32 having such a function because the support pin 8 is a cylindrical guide pin. In order to enter the guide bush 14 of the movable side mold plate 4 via the portion 9 (guide bush 13), there is a dimensional difference in which a collar 32 can be provided between the inner diameter of the guide bush 14 and the outer diameter of the support pin 8. Because it exists.

  FIG. 3 shows another example of the tapered surface 24 for guiding when the cylindrical guide pin portion 9 is fitted into the guide bush 14. In FIG. 3A, a tapered surface 24 is provided on the outer peripheral surface of the collar 32 so that the maximum diameter of the collar 32 is the same as or slightly smaller than the outer diameter of the cylindrical guide pin portion 9. In this case, smooth guide is possible without providing the guide bush 13 with a tapered surface, and the processed shape of the guide bush 13 can be simplified.

  The leading tapered surface 24 may be provided on the inner peripheral surface of the guide bush 14 as shown in FIG. Even if the guide bush 13 has a small diameter, it is easy to secure the guiding operation. Further, as shown in FIG. 3C, if the tapered surface 24 is provided on the cylindrical guide pin portion 9 (or the collar 32) and the tapered surface 24 is provided also on the guide bush 14 side, the guiding operation is more reliably performed. Will be made.

  The guide bush 13 having the cylindrical guide pin portion 9 is preferably fixed to the stationary side template 3 by the flange portion 21 and the snap ring 23 provided integrally with the guide bush 13 as described above. As shown in FIG. 4, a snap ring 23 or a flange 21 that contacts the surface of the fixed-side template 3 that faces the movable-side template 4 is provided on the proximal end side of the cylindrical guide pin portion 9 in the guide bush 13. You may go alone. Even in this case, the cylindrical guide pin portion 9 (guide bush 13) comes out of the fixed side mold plate 3 even if the resistance when the cylindrical guide pin portion 9 enters the guide bush 14 of the movable side mold plate 4 is large. There will be no such thing. Moreover, the mold structure used for manufacturing the guide bush 13 can be simplified.

  FIG. 5 shows an example of a molded product S molded with the above-described injection molding die. The illustrated molded product S, which is a main body part for a micro relay, has dimensions A, B, and C in the figure, respectively. The metal terminal pins P are formed at the same time as the fine sizes of 0.84 mm, 1.46 mm, and 0.53 mm.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an example of an embodiment of the present invention, where (a) is a cutaway perspective view, and (b) and (c) are cutaway front views of main parts. (a) is a cross-sectional view of main parts when the mold is opened, and (b) is a cross-sectional view of main parts when the mold is clamped. (a) (b) (c) is a partial sectional view of another example. (a) and (b) are further partial sectional views of other examples. It is a perspective view of an example of a molded article concerning the present invention.

Explanation of symbols

3 Fixed side template 4 Movable side template 8 Support pin 9 Cylindrical guide pin 13 Guide bush 14 Guide bush

Claims (7)

  A mold for injection molding in which a support pin is slidably inserted in a pair of mold plates, each mold plate having a guide bush in the insertion portion of the support pin, and the guide bush in one mold plate Has a cylindrical guide pin portion protruding toward the other mold plate, and a guide bush in the other mold plate has an inner diameter for slidably receiving the cylindrical guide pin portion. Mold.   A guide bush having a cylindrical guide pin portion provided on one template is a snap ring attached to a groove formed on the outer peripheral surface and is axially fixed to the one template. The injection mold according to claim 1, wherein the mold is an injection mold.   3. The injection according to claim 1, wherein at least one of the cylindrical guide pin portion and the guide bush for slidably receiving the cylindrical guide pin portion is provided with a tapered surface for guiding each other. Mold for molding.   The guide bush provided with the cylindrical guide pin portion is disposed on the fixed-side template, and is slidably inserted into the guide bush and has one end protruding from the distal end surface of the cylindrical guide pin portion. The support pin is characterized in that a collar having an outer diameter larger than the inner diameter of the cylindrical guide pin portion and smaller than the inner diameter of the guide bush disposed on the movable template is attached to the one end. The injection mold according to any one of claims 1 to 3.   5. The injection mold according to claim 4, wherein the collar is provided with a tapered surface for guiding the guide bush disposed on the movable side mold plate.   The injection mold according to any one of claims 1 to 5, wherein the mold is for molding a three-dimensional molded product having a fine size with a side of several mm or less.   A molded product, wherein the molded product is molded using the injection mold according to claim 6 and has a three-dimensional shape with a side of several mm or less.

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