JPH033385Y2 - - Google Patents

Description

[Detailed description of the invention] (a) Industrial application field The present invention relates to an injection mold used for molding synthetic resin, etc.

(b) Conventional technology Many attempts have been made to use one mold for molding many types of molded products.
Japanese Unexamined Patent Publication No. 55-67436 or Utility Model Application No. 59-79322
In the example disclosed in the above publication, a part of the mold is constituted by a replaceable insert, and the ejector pin is also replaced according to the insert, thereby solving the above problem.

(c) Problems to be solved by the invention A sleeve-shaped boss is often provided on the inner surface of a molded product, and this boss is formed using a sleeve pin, which is a type of ejector pin. Depending on the molded product, it may be necessary to change only the position of the sleeve boss. In such a case, since the basic shape of the molded product itself remains unchanged, it would be uneconomical to replace the insert as in the conventional example described above.
Therefore, the present invention is designed to achieve the objective with minimal changes to parts.

(d) Means for Solving the Problems In the present invention, a sleeve pin for forming the sleeve boss is attached to a sub-plate that is detachably attached to the back surface of the ejector plate. An ejector pin having the same diameter as the sleeve pin is also attached to this sub-plate at the position of the sleeve boss in the other molded product. The mounting plate that covers the back of the mold body is provided with a window for inserting and removing the sub-plate, and the core pin of the sleeve pin is attached to the lid plate that covers this window. Further, the cover plate is provided with a core pin attachment portion at a position aligned with the ejector pin.

(E) Operation When molding different types of molded products, remove the cover plate, take out the sub-plate, remove the ejector pin and sleeve pin that are present at the location where the sleeve boss is to be molded, and swap their positions.
After doing this, attach the sub-plate to the ejector plate again. Change the mounting position of the core pin so that it follows the sleeve pin, and then fit the cover plate into the window again. In this way, molded products with different sleeve boss positions can be molded.

(f) Example In the figure, 1 is a fixed mold, 2 is a movable mold, and 3 is a molded product molded in a cavity between the fixed mold 1 and the movable mold 2. There is a space 4 inside the movable mold 2 near the back surface, and an ejector plate 5 is arranged in this space. The ejector plate 5 is made by bolting together two plates 5a and 5b, and the head of an ejector pin 6 is inserted into the joint. 7 is a sub-plate placed on the back surface of the ejector plate 5. Like the ejector plate 5, the sub-plate 7 also consists of two plates 7a and 7b, and is fixed to the ejector plate 5 with bolts 8. Reference numeral 9 denotes a positioning pin protruding from the sub-plate 7, which is fitted into a positioning hole 10 of the ejector plate 5 to accurately position the sub-plate 7. A sleeve pin 12 for forming the sleeve boss 11 on the molded product 3 and an ejector pin 13 having the same outer diameter as the sleeve pin 12 are attached to the sub-plate 7. The sleeve pin 12 and the ejector pin 13 have heads of the same shape, and are planted in the sub-plate 7 with the heads sandwiched between the plates 7a and 7b. The ejector plate 5 is provided with through holes 14 and 15 through which the sleeve pin 12 and ejector pin 13 are passed. Thus, the ejector pin 13 is arranged at a position where the sleeve boss is to be molded in another molded product.

Reference numeral 16 denotes a mounting plate that covers the back surface of the main body of the movable mold 2, and serves as a mounting member for the molding machine. The mounting plate 16 is provided with a window 17 for taking the sub-plate 7 in and out, and this is covered with a cover plate 18.
The cover plate 18 is fixed to the mounting plate 16 with bolts 19.
A core pin 20 is used to form the hollow part of the sleeve boss 11, and projects from the cover plate 18 so as to pass through the sleeve pin 12. The core pin 20 is fixed by a set screw 21. The mounting part 22 of the core pin 20 is composed of a stepped hole part into which the shaft and head of the pin fit, and a female thread part into which a set screw is screwed. It is also provided at the locations where the lines are lined up. The plate 7b of the sub-plate 7 has through holes 24, 25 for passing the core pin 20, corresponding to the mounting parts 22, 23.
form. A spacer 26 having the same thickness as the sub-plate 7 is attached to the ejector plate 5 on the opposite side to balance the contact with the mounting plate 16. The mounting plate 16 is also provided with a through hole 28 through which the ejector rod 27 of the ejector plate 5 passes.

The operation of the above mold is shown in Figure 1 when the mold is closed.
Figure 2 shows the situation when the mold is opened, which is no different from normal molding operations. Now, when changing the position of the sleeve boss, remove the cover plate 18 as shown in FIG.
Take it out through the window 17 while disassembling it into parts b. Then, the positions of the sleeve pin 12 and ejector pin 13 are exchanged, and they are fixed to the ejector plate 5 again with the bolts 8. The cover plate 18 also has the core pin 20 attached to the mounting part 2.
After changing from 2 to 23, fix it to window 17 again. Thus, as shown in FIG. 4, preparations are made for molding molded products with different sleeve boss positions.

(G) Effects of the invention According to the invention, the sleeve boss position can be changed by replacing the positions of the sleeve pin, core pin, and ejector pin, making it extremely easy to change the specifications of the mold. In addition, the sleeve pin and ejector pin are attached to the sub-plate that is attached to the ejector plate, and the core pin is attached to the cover plate of the window that takes the sub-plate in and out. Therefore, when making changes, it is only necessary to remove the cover plate and sub-plate, and there is no need to make large-scale changes to the mold. No extensive disassembly is required and the work is quick.

[Brief explanation of the drawing]

The figures show an embodiment of the present invention, in which Fig. 1 shows when the mold is closed, Fig. 2 shows when the mold is opened, and Fig. 3 shows when the sleeve pin, core pin, and ejector pin are repositioned.
FIG. 4 is a cross-sectional view after the pins have been repositioned. Further, FIG. 5 is an enlarged view of the main part of FIG. 1, and FIG. 6 is an enlarged view of the main part of FIG. 3. 1... fixed type, 2... movable type, 3... molded product,
5...Ejector plate, 7...Sub plate, 11...Sleeve boss, 12...Sleeve pin, 13...Ejector pin, 16...Mounting plate,
17...Window, 18...Lid plate, 20...Core pin,
22, 23...Mounting part.

Claims (1)

[Scope of utility model registration request] A sleeve pin for forming a sleeve boss and an ejector pin having the same outer diameter are attached to a sub-plate that is detachably attached to the back surface of the ejector plate, and the positions of the sleeve pin and the ejector pin are interchangeable.
A mounting plate covering the back surface of the mold body is formed with a window through which the sub-plate can be taken in and out, and a plurality of core pins of the sleeve pin are inserted into the cover plate covering the window so as to maintain the combination relationship with the sleeve pin. An injection mold made by selecting and installing a specific mounting part.