JPH0261896B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a multicolor molding die used when molding push buttons, symbols in key tops, etc. using resins of different colors.

(Prior art) In an injection molding mold generally referred to as multi-color molding, in order to injection mold one molded product, a cavity part for primary molding and a cavity part for secondary molding, and two cavity parts for injection molding are used. At least one core part shared by the molds is required, and these molds are all replaced with other molds every time the molded product changes.

(Problems to be solved by the invention) For this reason, the mold is larger than normal injection molding using a single resin, so it takes time to replace the mold, and large replacement equipment must be used. However, there were problems such as difficult maintenance and increased mold costs.

Such problems can be solved by configuring the mold so that only the cavity and core parts can be replaced, as is done in some cases with ordinary injection molds, but many In color molding molds, it is often necessary to provide a pin member on the core side to create a flow hole for the resin that will form the secondary molded product in the primary molded product. When molding push buttons etc. in multiple colors, the numbers and letters that are primarily molded on them are
0, 6, 8, A, B, etc., it is essential to form flow holes within the numbers and letters to guide the secondary molding resin, and if the core is also configured to be replaceable, the flow holes must be formed within the numbers and letters. It must also be possible to replace the pin member forming the pin member and its actuating member.

For this reason, it is extremely difficult to solve the problems with multicolor molds by making only the cavity and core parts replaceable.

(Means for Solving the Problems) This invention was devised to solve the problems in the multicolor molding molds described above, and its purpose is to It is possible to replace the cavity and the core part without changing the pin member, and the core can be replaced along with the pin member while leaving the operating member of the pin member as is.This eliminates the need for large replacement equipment and reduces mold costs. The object of the present invention is to provide a new multicolor molding die that can reduce the

The present invention achieves the above object by removably embedding a block having a cavity and a core of a desired shape that close each other in the opening/closing surface of a split mold table, thereby forming two molding sets for primary molding and secondary molding. The cavity block is provided with a passage that communicates with the resin passage in the split mold table, and the core block is partially provided with flow holes for the resin that will form the secondary molded body in the primary molded body on the core surface. A pin member to be formed is inserted through the mold so that it can move forward and backward, and an actuating device for the pin member is installed inside the split mold base.

(Function) With the above configuration, the cavity block and core block of the split mold base can be replaced with other ones, and the connection between the pin member and the actuating member in the split mold base allows the primary Pores for the resin forming the secondary molded body can be formed in the molded body,
Even if the primary molded body is an endless number or letter, the resin can be allowed to flow into the inside of the primary molded body during secondary molding.

Further, the present invention will be specifically explained using illustrated examples.

(Example) In the figure, reference numerals 1 and 2 indicate a pair of split mold bases, which have horizontal grooves 3 and 4 opened at the same position on the opening/closing surface. Engaging step portions 5 and 6 are formed on both sides of the lateral grooves 3 and 4, and one of the split mold bases 1 is provided with a gate 7 and a resin path 8 that reaches the lateral grooves 3.

Further, inside the other split mold table 2, a pin member actuating device 9, which will be described later, is provided. This actuating device 9 is composed of a lever member 11 rotatably supported in a space 10 in a split-type table, and a pair of actuating rods 12 and 13 that abut both ends of the lever member 11. .

The operating rod 12 is movably inserted between the horizontal groove 4 and the space 10, and the operating rod 13 extends through the opening/closing surface and the space 10, with the tip protruding from the opening/closing surface being connected to the other side. When pressed into contact with the opening/closing surface of the split mold table 1, the lever member 11 is pressed, and the other operating rod 12 is conversely projected in the direction of the horizontal groove.

A cavity block 14 and a core block 15 having engagement step portions 5a, 6a on both sides are fitted into each of the lateral grooves 3, 4.

This cavity block 14 and core block 1
5 is a cavity 14a and a core 15 that close together.
A passage 8a communicating with the resin passage 8 is bored in the cavity block 14, and a pin member 16 in the same position as the operating rod 12 is passed through the core block 15.

A coil spring 17 is fitted around the pin member 16, and the coil spring 17 is fitted around the pin member 16.
One end of the pin member 7 is brought into contact with the flange 16a at the end of the pin member 6, and the other end is brought into elastic contact with the core block side, thereby constantly pressing the pin member 16 inward.

The cavity block 14 and core block 15 are fitted into the lateral grooves 3 and 4 from the sides of the split mold bases 1 and 2, respectively, and set at a position where the cavity 14a and the core 15a are closed to each other. .

Further, the operating rod 12 and the pin member 16 are positioned by this set, and when the other operating rod 13 is pushed in by the opening/closing surface of the split mold base 1, the operating rod 12 is pinned via the lever member 11. The member 16 is pressed against the coil spring 17, and the pin tip is pushed out from the core end face into the cavity 14a.

Figure 4 shows two sets of split mold tables 1 and 2, a fixed platen 18 of the mold clamping mechanism, and a movable platen 2 connected to the mold clamping ram 19.
This figure shows a case in which multi-color molding is performed by attaching them at symmetrical positions with a rotary disk 20a that is rotatably connected in a rotary plate 20a. Board 20
It reciprocates 180° with a.

Further, one cavity of the cavity blocks 14, 14 embedded in the split mold tables 1, 1 forms a primary molded body a, and the other cavity forms a secondary molded body b on the primary molded body a.

When the mold is closed, the tip of the pin member 16 protrudes into the cavity under the action of the operating rod 13 pushed in by the opening/closing surface of the split mold table 1 on the primary molding side, and the primary molding is injection molded there. Located within body a.

However, when the mold is opened, the pressing force on the operating rod 13 is removed, and on the secondary molding side, the tip of the operating rod 13 fits into the recess 22 provided in the split mold table 1, so there is nothing to press the operating rod 13. , the actuating device 9 becomes free, and the pin member 16 is retracted by the coil spring 17 until its tip is located on the core surface.

As a result, the pin mark becomes a flow hole 23 (see Figures 2 and 3) that communicates between the inside and outside of the primary molded body a, and even if the number of the primary molded body a is 0 or D, the resin remains in the flow hole. 22 to form a secondary molded body b which becomes a main body on the front side of the primary molded body a.

In addition, when it is not necessary to form flow holes 23 in the primary molded body a, a recess 22 similar to that on the secondary molding side is formed on the primary molding side of the split mold table 1, and when the mold is closed, the operating rod 13 You don't have to press it. Therefore, the flow holes 23 can be formed by the pin member 16 depending on the shape, such as the number, formed as the primary molded body a.

Note that 24 and 25 in the figure are injection devices.

The embodiment shown in FIG.
5 and 15 are embedded in the split mold table 2. The pin members 16 and 16 inserted through each core block 15 and 15 are connected to the actuating plate 26 in the cavity 10.
It is connected to.

Return rods 27, 27 extending through the split mold base 2 are attached to both ends of the actuating plate 26, and the cam-shaped end 11a of the lever member 11 is in contact with the lower side of both ends. There is.

At the rear end of the lever member 11, an operating rod 13 penetrating through the split mold base 2 is provided, similar to the previous embodiment, and by alternately moving this operating rod 13 and the return rods 27, 27, the actuating rod 13 is moved. 26 is reciprocated so that each pin member 16, 16 can be moved in and out at the same time.

With this configuration, molding for multiple pieces can be performed in the same way.

In addition, in the above embodiment, two sets of molding parts for primary molding and secondary molding were constructed using two sets of molds. It goes without saying that the same method can be used even if the mold is rotated using the center of the mold as a fulcrum.

(Effects of the Invention) As described above, the present invention is capable of forming two sets of molds for primary molding and secondary molding from a split mold table and a cavity block and a core block that are removably embedded in the opening/closing surface of the mold table. Since the actuating device for the pin member that forms the core block and extends through the core block is installed inside the split mold base, it has the following effects.

1. Since it is sufficient to make the cavity block and core block according to the molded product, the mold cost is lower than when the entire mold is made for each molded product, and the manufacturing cost of the molded product is also lowered.

2. Since the mold can be replaced for each molded product by simply replacing each block while leaving the split mold stand as is, molds can be easily and safely replaced without using large replacement equipment such as an overhead crane. Exchanges can be made.

3 The pin member that forms the resin flow hole in the primary molded body and its actuating device are provided separately in the core block and the split mold stand, so the actuating device does not become an obstacle when replacing the core block. It also has the convenience of being able to operate the pin member in the replaced core block in its original state.

[Brief explanation of drawings]

The drawings illustrate a multicolor mold according to the present invention, and FIG. 1 is a longitudinal sectional side view of a pair of split mold bases, FIG. 2 is a longitudinal sectional side view of a cavity block and a core block, and FIG. A surface view of the core-side mold in a state in which the primary molded body is injection-molded, FIG. 4 is a schematic longitudinal sectional side view when the multicolor mold is attached to the mold clamping mechanism, and FIG. 5 is another example. FIG. 1, 2...Divided base, 3, 4...Horizontal groove, 8...
Resin path, 8a... Passage, 9... Actuation device, 11...
... Lever member, 12, 13 ... Operating rod, 14 ...
Cavity block, 14a... Cavity, 1
5... Core block, 15a... Core, 16...
pin member.

Claims (1)

[Claims] 1. Two sets of molding parts for primary molding and secondary molding are constructed by removably embedding a block having a cavity and a core of a desired shape that close each other in the opening/closing surface of the split mold table, and A passage communicating with the resin passage in the split mold table is provided in the cavity block, and a pin member is moved back and forth in the core block to partially form flow holes for the resin that will form the secondary molded body in the primary molded body on the core surface. A mold for multicolor molding, characterized in that the pin member is freely inserted through the mold, and an actuating device for the pin member is installed inside the split mold stand.