JPS6212572Y2 - - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention relates to an injection mold used for molding synthetic resin, etc.

B. Prior Art One of the ways to reduce mold manufacturing costs is to configure the main parts with replaceable inserts. In other words, the main body of the mold is shared, the necessary parts of the molding part are nested, and the nests are replaced depending on the type of molded product. An example of such a mold is shown in FIG. In the figure, 1 is a fixed type and 2 is a movable type. The movable mold 2 is constructed by attaching two types of molding inserts 4 and 5 to the front surface of a main body 3, and one of the molding inserts 5 is an insert that is replaced depending on the type of molded product. 6 is a molded product that is molded into a cavity between the fixed mold 1 and the mold inserts 4 and 5. There is a space 7 inside the movable mold 2 near the back surface, and an ejector plate 8 is placed in this space. The ejector plate 8 is made by bolting two plates 8a and 8b together, and the head of the ejector pin is sandwiched in the joint, and the shaft of the pin protrudes through the plate 8a. be. Here, the ejector pin corresponding to insert 4 is marked with 9,
10,1 for the ejector pin corresponding to nest 5
Marked with 1. The ejector pin 11 corresponds to the boss 12 formed in the molded product 6, and unlike other ejector pins, it is hollow. I'm passing through. The head of the core pin 13 is fixed to a mounting plate 14 covering the back surface of the main body 3 with a set screw 15, and the shaft portion passes through the mounting plate 14 and the plate 8b and is attached to the ejector pin 1.
1. When opening the mold, mounting plate 1
When the movable mold 2 attached to the molding machine is moved backward by step 4, the ejecting rod 1 is waiting on the way.
6 enters the space 7 through the hole 17 of the mounting plate 14 and pushes the ejector plate 8, whereby the ejector pins 9, 10, 11 protrude from the surfaces of the inserts 4, 5 and push the molded product 6 down. This operation is no different from that of a normal injection mold.

Now, regarding the case of replacing the insert 5, the ejector pins 10 and 11 are also used for the new insert.
There is no problem if you can use it in the same position.
However, in reality, in most cases, if the molded shape differs, the arrangement of the ejector pins must also be changed. Therefore, the ejector pin through holes 18 and 19 provided in the main body 3 and the plate 8a are located in addition to the positions where the ejector pins 10 and 11 currently pass.
The ejector pins 10 and 11 that have been rearranged are also drilled at the positions where they should pass, and the core pin through holes 20 and 21 provided in the plate 8b and the mounting plate 14 are similarly arranged in various patterns, and the ejector pins 9 can be inserted as needed. , 10, 11 and the core pin 13 will be rearranged. However, this was a difficult task, and as shown in Figure 2, the mounting plate 1
Separate the core pin 13 from the mounting plate 14.
It was necessary to follow the steps of separating it from the main body 3 to expose the space 7, separating the plates 8a and 8b, and then repositioning them.

Ideas for solving the above-mentioned inconveniences have been proposed in the past. This is what was described in Patent Application Publication No. 67436 of 1981. The key points of the configuration are: a) Replace the ejector pin from the nesting side.
For this purpose, a hole large enough to allow the head of the ejector pin to pass through is bored in the main body.

b The head of the ejector pin is simply placed against the front of the ejector plate, and in order to maintain contact between the two, a spring is inserted between the insert and the pin head to press the pin against the plate.

At the point. The difficulty with this method is that a hole large enough to pass the head of the ejector pin must be bored in the main body. In other words, if holes are drilled according to several types of arrangement patterns, the large holes may end up being lined up so as to overlap with each other, which will significantly weaken the strength of the mold body.

C. Purpose of the invention The object of the invention is to provide an injection molding mold having a structure in which the ejector pins can be easily rearranged, and this does not affect the strength.

D. Structure of the invention In the invention, only the ejector pins that require rearrangement are assembled into a small sub-plate, and this sub-plate is attached to the back surface of the ejector plate. The ejector pin of the sub-plate passes through the ejector plate. The mounting plate on the back of the mold body is provided with a window through which the sub-plate can be taken in and out, and when replacing the insert, the sub-plate is pulled out from this window and replaced with a sub-plate with a new pin arrangement.

E. Embodiment An embodiment will be described based on FIG. 3 and subsequent figures. Components that correspond directly to the structure of the prior art explained in FIGS. 1 and 2 are given the same reference numerals used in the explanation of the prior art, and the explanation thereof will be omitted. 22 is a sub-plate which is the main point of the present invention. The sub-plate 22 is made up of two stacked plates 22a and 22b like the ejector plate 8, and has an insert 5.
The heads of the ejector pins 10 and 11 are sandwiched between the joints, and the shafts of the pins protrude from the front surface of the plate 22a. Since only the ejector pins for the nest 5 are attached, the area is smaller than the ejector plate 8. Ejector pins 10 and 11 which were provided only on the plate 8a in the prior art
A through hole for the ejector pin 1 is also provided continuously in the plate 8b here, and the ejector pin 1 is inserted into this through hole.
Sub plate 2, passing through 0 and 11.
2 is applied to the back surface of the ejector plate 8. A positioning pin 23 protrudes from the sub-plate 22 in parallel with the ejector pin, and the ejector plate 8 has a positioning hole 2 for receiving it.
4 is provided. On the other hand, the mounting plate 14 is provided with a window 25 through which the sub-plate 22 is inserted and removed. window 2
5 is provided with a lid 26, and the core pin 1 is attached to this lid 26.
Attach 3. Note that the sub-plate 22 is connected to the ejector plate 8, and the lid 26 is connected to the mounting plate 14.
are fixed with bolts 27 and 28, respectively, and these bolts 27 and 28 are represented by arrow-shaped symbols in FIGS. 3 to 6. Reference numeral 29 denotes a spacer attached to the ejector plate 8 so as to be located at the end opposite to the sub-plate 22 in order to balance the contact with the mounting plate 14.

The operation of this embodiment is as follows. Third
The figure shows the situation when the mold is closed, and Figure 4 shows the situation when the mold is opened, and this is no different from normal molding work. Now, when replacing the insert 5, as shown in FIG. 5, the lid 26 is removed, the sub-plate 22 is taken out from the window 25, and the ejector pins 10, 11 and core pin 13 are rearranged. You can further speed up the work by preparing multiple sub-plates with pin arrangements that match the type of nesting. Lid 2 with core pin 13 planted
The same applies to 6.

F. Effects of the invention According to the invention, the ejector pin can be rearranged simply by inserting and removing the sub-plate provided on the mounting plate on the back of the mold body, so there is no need to disassemble the mounting plate and even the ejector plate as in the conventional method. There are no problems and work can be done quickly. Further, the ejector pin through hole bored in the mold body can be a small diameter hole through which only the shaft portion of the pin passes, so that it does not adversely affect the strength of the mold.

[Brief explanation of the drawing]

1 and 2 are cross-sectional views of a mold having a conventional structure, with FIG. 1 showing the state when the mold is closed, and FIG. 2 showing the state when the ejector pin arrangement is changed. Figure 3 and the following are cross-sectional views showing an embodiment of the present invention. Figure 3 shows the state when the mold is closed, Figure 4 shows the state when the mold is opened, Figure 5 shows the state when the ejector pin is rearranged, and Figure 6 shows the state when the ejector pin is rearranged. is an enlarged view of the main part of FIG. 3, and FIG. 7 is an enlarged view of the main part of FIG. 5. 1... Fixed type, 2... Movable type, 3... Movable main body, 8... Ejector plate, 18, 19...
Ejector pin, through hole, 5...molded insert, 22
...Subplate, 10,11...Ejector pin, 14...Mounting plate, 25...Window.

Claims (1)

[Scope of utility model registration request] In a mold body in which a replaceable mold insert is combined, the mold body and the ejector plate disposed inside the mold body are provided with through holes for inserting ejector pins, so that the ejector pins required for multiple types of mold inserts are inserted. In addition to making holes so that the arrangement pattern can be configured, a sub-plate with protruding ejector pins suitable for the molding insert to be used is attached to the back surface of the ejector plate, and the sub-plate covers the back surface of the mold body. An injection molding mold having a mounting plate provided with a window through which the sub-plate can be taken in and out.