JP3152787B2 - Injection mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for injection molding for performing plastic injection molding, and more particularly to a mold for easily accommodating a plurality of nests with one mold.

[0002]

2. Description of the Related Art FIG.
FIG. 10 is a partial sectional side view showing an example of a conventional three-plate mold having a runner stripper plate. 1 in the figure
Is the fixed side mounting plate, 2 is the runner stripper plate, 3
Is a fixed mold plate, 4 is a movable mold plate, 5 is a backup plate, 6 is a spacer block, 7 is an ejector plate, 8 is an ejector plate lower, and 9 is a movable mounting plate. In the drawing, 11 is a fixed-side insert, 12 is a movable-side insert, 13 is a primary sprue formed in the sprue bush,
14 is a runner, 15 is a fixed side mold plate 3 and a fixed side insert 11
A secondary sprue formed in the secondary sprue 15
Communicates with a cavity 16 formed between the fixed side insert 11 and the movable side insert 12. FIG. 9 shows the mold clamping state, and FIG. 10 shows the mold open state. In FIG.

In such a conventional three-plate mold having a runner stripper plate, when an attempt is made to accommodate a plurality of inserts (product parts) without changing the main part of one mold, a fixed side is required. The insert 11 and the same number of runner stopper plates are required in accordance with the insert 11, which leads to an increase in the number of processes and an increase in storage space. In addition, when the runner stripper plate is used in common, the degree of freedom in design becomes extremely narrow. Therefore, there is a problem in that there are many limitations in making a mold that can be actually used, and there is a problem that it is difficult. Of course, the same problem occurs with the fixed mounting plate.

FIG. 15 is a partial sectional side view showing an example of a conventional three-plate mold having ejector pins for projecting a product. This mold is structurally almost the same as the molds shown in FIGS. 9 and 10, and the ejector pin 19 has a flange 2 at the end.
0, so that the flange 20 is sandwiched and held between the upper ejector plate 7 and the lower ejector plate 8.

In this type of mold, when one mold (mold base) is used to accommodate a plurality of inserts (product parts), the flange 20 of the ejector pin 19 is present, so that the mold 20 is movable. It is necessary to disassemble and reassemble the mold with the replacement of the side insert 12 or to have a complicated structure combining two or more plates. There was also a problem in terms of cost.

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and an injection molding die capable of reducing the cost by remodeling only the nested portion with one die body (mold base). The purpose is to provide.

[0007]

In order to achieve the above object, an injection mold according to the present invention has an insert having a cavity, which is removably attached to an insert set recess of a mold body. In the mold, the fixed side mold plate recess for setting the fixed side insert is penetrated in the die removing direction, and one side surface is opened to allow the fixed side insert to be freely inserted and removed in the direction along the side surface. And the runner portion is provided on the opposite side of the fixed side insert, and the outer side surface of the fixed side insert and the inner side surface holding the fixed side insert of the fixed side mold plate concave portion are provided with a concave and convex engaging portion to be detachable, Further, an opening is provided in the fixed-side mounting plate, and a holding plate provided with a hole for fixing the runner lock pin is detachably held.

In order to achieve the above object, an injection mold according to the present invention is an injection mold in which a nest having a cavity is removably mounted in a nest set recess of a mold body. The movable side mold plate in which the child is set penetrates in the direction of die removal, and one side is opened to allow the movable side insert to be freely inserted and removed in the direction along the side, and the projection pin is a straight cylinder without a flange. The shape is such that it can be inserted into and removed from the ejector plate side through a pin hole provided in the movable side insert, and the end of the protruding pin is fixed to the upper surface of the ejector plate.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. In the following, only parts common to the related art will be given the same reference numerals, and duplicate description will be omitted.

FIGS. 1 to 7 show a first embodiment of an injection mold according to the present invention. This embodiment is a mold without a runner stripper plate, and has no runner stripper plate, and the structures of the fixed side mold plate 30, the fixed side insert 31 and the fixed side mounting plate 32 are the same as those shown in FIGS. Is different from

The fixed side mold plate 30 has a concave portion 33 for setting the fixed side insert 31 penetrated in the die removing direction, and one side surface is opened to allow the fixed side insert 31 to be inserted therefrom, as shown in FIGS. It can be freely inserted and removed in the horizontal direction. On the other hand, the fixed side insert 31 is provided on the upper surface in the drawing, that is,
The next sprue 15 is provided, has the same thickness as the fixed-side mold plate 30, and fits exactly into the recess 33 of the fixed-side mold plate 30. And the fixed side template 30
Key grooves 34, 3
4 are provided, and key projections 35, 35 (only one is shown in the figure) are provided on the outer surface of the fixed-side insert 31.
Therefore, in order to mount the fixed side insert 31 in the concave portion 33 of the fixed side template 30, the key protrusion 35 is engaged with the key groove 34 at the opening of the concave portion 33, and the key protrusion 35 is slid. Just slide it out of the opening and pull it out.
The fixed side insert 31 can be easily replaced. The key groove 34 and the key projection 35 prevent the insert from falling off when the mold is opened (FIG. 2), and other means such as a groove may be employed. The fixed-side insert 31 is fixed to the fixed-side mold plate 30 with bolts or the like, not shown.

As shown in FIGS. 3 and 4, a holding plate 36 for holding a runner lock pin is
There is provided an opening 37 for mounting. The holding plate 36 is shown in FIG.
As shown in FIG. 6, the two side edges have a stepped shape, and the inner surface of the opening 37 has a stepped shape corresponding to the holding plate 36 so as to detachably hold the holding plate 36. . As shown in FIG. 7, the holding plate 36 is provided with a hole 39 for inserting a runner lock pin 38.
A plurality of holding plates 36 are prepared so as to be able to cope with a change in the position of the runner lock pin 38 due to the replacement of the fixed-side insert 31, so that the gate can be reliably cut and a trouble at the time of mold release is prevented.

In this embodiment, as shown in FIG. 2, the runner is removed from the runner take-out space 17 between the fixed mounting plate 32 and the fixed mold plate 30, and the product is moved with the fixed mold plate 30 as in the prior art. Product take-out space 18 between side templates 4
Remove from Further, in the mold of the present embodiment, when one mold (mold base) is to accommodate a plurality of nests, if the mold is opened, only the fixed nest 32 can be freely moved from the fixed mold plate 30. It can be pulled out to incorporate another fixed side insert, and if necessary, the holding plate 36 can be attached to the fixed side mounting plate 3.
The runner lock pin 38 can be changed in position by removing it from the upper surface side and replacing it.

FIG. 8 shows a second example of the injection mold according to the present invention.
An example will be described. In this embodiment, the shapes and structures of the movable mold plate 40, the movable insert 41 and the ejector pins 42 are different from those of the conventional one shown in FIG.

The movable mold plate 40 has a recess 43 for setting the movable insert 41 penetrated in the die-cutting direction, and one side is opened to allow the movable insert 41 to move in the horizontal direction of FIG. It can be inserted and removed freely. On the other hand, movable side insert 41
Has the same thickness as the movable mold 40, and the movable mold 40
Is fitted into the concave portion 43 of the helmet.
Steps 44, 44 are provided on two opposing inner surfaces of the concave portion 43 of the movable mold plate 40.
Steps 45, 45 on the outer surface of 1 (only one is shown in the figure)
Is provided. For this reason, the movable side insert 41 is connected to the movable side mold plate 4.
In order to mount the concave portion 43, the step 4
4, the step 45 is engaged and comes to slide,
In addition, it is only necessary to slide it out of the opening and pull it out, and the movable side insert 31 can be easily replaced. Further, the movable side insert 41 is fixed to the movable side mold plate 40 by bolts or the like, not shown.

The ejector pin 42 has a straight cylindrical shape and does not have a flange at the lower end. For this reason, it is possible to insert the movable side insert 41 and the backup plate 5 from the product removal space 18 in the mold open state.
The ejector pin 42 has a lower end fixed to the upper surface of the upper portion 7 of the ejector plate 7 with an instant adhesive or a magnet, so that the ejector pin 42 can be interlocked with the upper portion 7 of the ejector plate.

[0017]

As described above, the injection mold according to claim 1 has the runner portion and the secondary sprue portion on the fixed side insert, and is detachable from the side surface of the mold.
When a single mold (mold base) is used for multiple inserts, only the fixed inserts need to be replaced, and the runner stopper plate replacement required for the conventional mold, the mold release process, etc. Therefore, there is an effect that it is possible to make a mold at a low cost in terms of manufacturing cost. By not using the runner stopper plate, the thickness of the entire mold is reduced, so that the fixed mold plate or the movable mold plate can be made thicker. There is an effect that it is possible to cope with the molded products of the above. Furthermore, in the injection molding process, the amount of runner material is reduced, so that waste of material is minimized, and the mold opening amount is small, so the molding cycle is shortened, and puller bolts and the like are not required on the mold structure. Therefore, there is an effect that simplicity is improved, and assemblability and design flexibility are improved.

As described above, the injection mold according to the second aspect of the present invention allows the movable side insert to be detachable from the side of the mold, so that it can be detached even after the movable side insert is once fixed. Therefore, there is an effect that the step of changing the mold (mold base), which has been conventionally required when changing the insert portion, becomes unnecessary. In addition, the ejector pin has a straight cylindrical shape without a flange, so that when the mold is opened, it can be inserted into the movable side insert from the product removal space formed between the fixed side mold plate and the movable side mold plate, and the lower end of the ejector plate The interlock with the ejector plate can be achieved simply by fixing it to the upper surface with an instantaneous adhesive, a magnet, or the like, and there is an effect that the exchange workability in the injection molding process can be improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing a first embodiment of an injection mold according to the present invention.

FIG. 2 is a partial sectional side view showing a mold open state of the mold of FIG. 1;

FIG. 3 is a partial plan view of a fixed-side mounting plate of the mold shown in FIG. 1;

FIG. 4 is a partial side sectional view of a fixed-side mounting plate of the mold of FIG. 1;

FIG. 5 is a side view showing a holding plate for a runner lock pin attached to the fixed-side attachment plate in FIGS. 3 and 4;

FIG. 6 is a plan view showing a holding plate for a runner lock pin attached to the fixed-side attachment plate in FIGS. 3 and 4;

FIG. 7 is a partial sectional view showing attachment of a runner lock pin to the holding plate of FIGS. 5 and 6.

FIG. 8 is a partial sectional side view showing a second embodiment of the injection mold according to the present invention.

FIG. 9 is a partial cross-sectional side view illustrating an example of a conventional injection mold.

FIG. 10 is a partial sectional side view showing a mold open state of the mold of FIG. 9;

FIG. 11 is a partial sectional side view showing another example of a conventional injection mold.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 fixed side mounting plate 2 runner stripper plate 3 fixed side template 4 movable side template 5 backup plate 6 spacer block 7 above ejector plate 8 below ejector plate 9 movable side mounting plate 11 fixed side insert 12 movable side insert 13 1 Next sprue 14 Runner 15 Secondary sprue 16 Cavity 17 Runner take-out space 18 Product take-out space 19 Ejector pin 20 Flange 30 Fixed side mold plate 31 Fixed side insert 32 Fixed side mounting plate 33 Recess 34 Key groove 35 Key protrusion 36 Holding plate 37 Opening 38 Runner lock pin 39 Hole 40 Movable mold plate 41 Movable insert 42 Ejector pin 43 Recess 44, 45 Step

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hideki Shoji 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (56) References JP-A-6-15651 (JP, A) JP-A-Hei 5-245903 (JP, A) JP-A-4-350949 (JP, A) JP-A-4-272816 (JP, A) JP-A-4-39016 (JP, A) JP-A-1-123715 (JP, A A) JP-A-63-9519 (JP, A) JP-A-61-227011 (JP, A) JP-A-6-179217 (JP, A) JP-A 5-60817 (JP, U) JP-A-53 -97174 (JP, U) Japanese Utility Model 1-100666 (JP, U) Japanese Utility Model 4-128820 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B29C 45/26- 45/44

Claims (2)

(57) [Claims] In an injection molding die for removably attaching a nest having a cavity to a nest setting recess of a mold body, a fixed-side mold plate recess for setting a fixed-side nest is made to penetrate in a die removing direction. One side is opened so that the fixed side insert can be inserted and removed in the direction along the side, and the secondary sprue and the runner portion are provided on the side opposite to the product of the fixed side insert. An inner surface for holding the fixed-side insert of the fixed-side mold plate recess is provided with an uneven engagement portion to make it detachable, and an opening is provided in the fixed-side mounting plate, and a hole for fixing the runner lock pin is provided. A mold for injection molding characterized in that a plate is detachably held. 2. An injection molding die in which a nest having a cavity is removably mounted in a nest setting recess of a mold body, and a movable mold plate recess for setting a movable nest is penetrated in a die removing direction. And one side is opened so that the movable side insert can be freely inserted and removed in the direction along the side, and the protruding pin is formed into a straight cylindrical shape without a flange from the pin hole provided in the movable side insert to the ejector plate side. It can be inserted and removed freely,
In addition, an end of the protruding pin is fixed to an upper surface of the ejector plate.