JPH0138657B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to the multicolor resin molding method of the present invention and improvements to the multicolor resin mold used therein.

The present invention can be utilized in various industrial fields such as the plastic molding industry, which requires multicolored resin molded bodies molded with different resins.

[Prior art] One regular mold that is always used and at least two first and second replacement molds that are used interchangeably are molded from resins that have different colors. Multicolored resin molded bodies are known. In this conventional multicolor resin molding method, a regular mold and a first exchange mold are brought into contact with each other, and a first resin is injected into a first cavity of the mold to form a first resin molded body. With this first resin molded body fixed to the regular mold, the first
The replaceable mold is replaced with a second replaceable mold, and a second resin is injected into the second cavity between the regular mold and the second replaceable mold to form a second resin molded body, and the second resin molded body and the first resin molded body are injected. A multicolored resin molded body made of a second resin molded body was manufactured.

[Problems to be Solved by the Invention] In the above-described conventional method for producing a multicolored resin molded body, the second resin molded body contacts the first resin molded body in a molten state within the second cavity, and solidifies therein to form the second resin molded body. The two resin molded bodies are integrally formed with the first resin molded body, and a multicolored resin molded body is obtained. When the affinity of both the resins constituting the first resin molded body and the second resin molded body is high, the bond between the two molded bodies is strong and a multicolored resin molded body with high integrity can be obtained. However, when one resin is polyethylene and the other resin is vinyl chloride resin, the affinity between the resins is low, so the multicolored resin molding obtained by the above conventional method is The bonding force between the body and the second resin molded body is weak, causing a problem of separation during use.

An object of the present invention is to provide a multicolor resin molding method and a multicolor resin molding die that produce a multicolor resin molded article with high integrity even between resins with low affinity.

[Means for Solving the Problems] The multicolor resin molding method of the present invention includes a main body constituting a main part, a main body fixedly held on the main body at least at a first position and a second position of the main body. a regular mold consisting of a movable body forming a mold surface of the part; at least two first exchange molds and a second mold that come into contact with the regular mold to form different first and second cavities, respectively;
First, a multi-colored resin mold consisting of a replaceable mold is used, and the movable body of the regular mold is fixed at the first position of the main body, and the regular mold and the first replaceable mold are brought into contact with each other. 1 step, filling a first resin into a first cavity formed by the regular mold and the first exchange mold;
A second step of forming a first resin molded body having through-holes at certain locations, separating the first exchangeable mold from the regular mold, and then moving the movable body of the regular mold to the second position of the main body. a third step of moving and separating a part of the mold surface of the regular mold that has formed the first resin molded body from the first resin molded body; and a fourth step of bringing the second exchange mold into contact with the regular mold. step, injecting air from the regular mold side of the first resin molded body into a second cavity formed by at least a mold surface separated from the first molded body of the regular mold and a mold surface of the second exchangeable mold. Filling the second resin through the through hole,
a fifth step of integrally forming a second resin molded body with the first resin molded body to form a multicolored resin molded body; separating the second exchangeable mold from the conventional mold; and the obtained multicolored resin; The method is characterized in that the sixth step of taking out the molded body is carried out sequentially.

Furthermore, the multicolor resin molding mold of the present invention includes a regular mold constituting one of the split molds, and at least two first exchangeable molds and a second replaceable mold that come into contact with the regular mold to form different first and second cavities, respectively. In a multicolor resin molding mold consisting of two exchangeable molds, the regular mold has a main body constituting its main part, and a first position of the main body when the regular mold is in contact with the first exchangeable mold. and a movable body that is fixed to a second position of the main body when it is in contact with the second replaceable mold, and the movable body slides within the main body, and the regular mold is fixed to the second position of the main body. When it is in contact with the first exchangeable mold, one end thereof is in contact with the mold surface of the first exchangeable mold, and when the regular use mold is in contact with the second exchangeable mold, it retreats into the main body and is inside the main body. at least one sliding member forming a through hole communicating with the second cavity, at least a part of the second cavity is formed closer to the regular mold than the first resin molded body; The second resin is filled into the cavity through the through hole from the conventional mold side of the first resin molded body obtained by filling and molding the first resin into the first cavity. It is something to do.

In the multicolor resin molding method and multicolor resin mold of the present invention, after molding the first resin molded body, the main body and the movable body that constitute the regular mold move relatively,
A part of the surface of the first molded resin molded body and a part of the mold surface of the conventional mold are separated, and a space, that is, a space that becomes an undercut part is formed at the rear of the first resin molded body. . For this reason, when the second resin molded body is molded, the second resin molded body partially wraps around the back of the first resin molded body, forming a so-called undercut portion. Therefore, the first resin molded body is mechanically held and fixed by the second resin molded body. As a result, even if the affinity between the resins of the first resin molded body and the second resin molded body is low and the bonding strength is weak, the second resin molded body mechanically fixes the first resin molded body. In addition, it is possible to obtain a multicolored resin molded article that has high integrity and does not separate even when resins have low affinity.

[Detailed Description of the Structure of the Invention] The multicolor resin molding mold of the present invention is composed of a regular mold and at least two first and second exchange molds.
And this commonly used type has its own characteristics.

The regular type consists of a main body and a movable body. The movable body is fixedly held with respect to the main body at least at a first position and a second position of the main body.
The first position is a position where the movable body is fixed when the regular mold comes into contact with the first replaceable mold, and the second position is where the movable body is fixed when the regular mold comes into contact with the second replaceable mold. One end surface of the movable body constitutes at least a part of the mold surface forming the cavity in each fixed holding position.

The relative relationship between the first position and the second position of the movable body is such that the movable body protrudes toward the cavity side with respect to the main body or conversely retreats. When the movable body protrudes, the first
The resin molded body is protruded from the main body while being held by the movable body. Conversely, when the movable body retreats, the first resin molded body formed by the first exchangeable mold is held by the main body, and the movable body retreats in a direction in which it is separated from the first resin molded body.

A space is formed behind the first resin molded body by this relative movement between the main body and the movable body (this space forms part of the second cavity when the second exchangeable mold is in contact with the regular mold). do). moreover,
The movable body has at least one sliding member that slides within the main body. When the regular mold is in contact with the first replaceable mold, one end of this sliding member comes into contact with the mold surface of the first replaceable mold, and when the regular mold is in contact with the second replaceable mold, it retreats into the main body. A through hole communicating with the second cavity is formed inside the main body. The second resin is filled into the second cavity from the conventional mold side of the first resin molded body through this through hole.

Specifically, the movable body is configured as a core pin, a core block, or the like. Note that a part of the end surface of the movable body may come into contact with the mold surfaces of the first exchangeable mold and the second exchangeable mold.

Relative movement between the main body and the movable body can be performed using a biasing force of a coil spring, a hydraulic cylinder device, or the like. Also, regarding fixing the main body and movable body,
This can be accomplished through the use of wedge-shaped gaps, locking pins, or other locking mechanisms.

The first step of the multicolor resin molding method is a step of bringing the regular mold and the first exchange mold into contact with each other with the movable body fixed at the first position to form a first cavity.

Note that the first exchangeable mold and the second exchangeable mold have mold surfaces for forming predetermined first and second resin molded bodies, respectively, and both the first and second exchangeable molds are substantially the same as conventional ones. There is no special difference from the exchange type of .

The second step is a step of filling a first resin into a first cavity formed by a regular mold and a first exchange mold to form a first resin molded body having a through hole at at least one location.

As the resin, thermoplastic resin is generally used, but thermosetting resin, rubber, etc. may also be used. Further, although the resin is generally filled into the first cavity by injection molding, it may be filled by other methods.

The third step is a step of separating the first replaceable mold from the regular mold, and then moving the movable body of the regular mold to the second position of the main body.

When separating the first replacement mold from the regular mold, the molded first resin molded body is held in the regular mold. Next, when the movable body is moved to the second position relative to the main body, the first resin molded body is separated from either the main body or the movable body and held by the other. Then, a part of the surface of the first resin molded body formed by the mold surface of the conventional mold is separated from a part of the mold surface of the conventional mold.

The fourth step is to bring the second replacement mold into contact with the regular mold,
This is a step of forming a second cavity.

The fifth step is to fill the cavity formed by the regular mold and the second exchange mold with a second resin from the regular mold side of the first resin molded body through the through hole of the first resin molded body, and fill the cavity formed by the regular mold and the second exchange mold with the second resin. This is a step of forming a second resin molded body integrally with the molded body to form a multicolored resin molded body.

This second resin molded body fills the remaining second cavity space occupied by the first resin molded body.
In other words, the space between the first resin molded body and the regular mold formed by the relative movement between the movable body of the regular mold and the main body (the space behind the first resin molded body, that is, the space behind the first resin molded body) There is also a second space (space on the regular type side).
The resin molded body is filled with resin. For this reason, the second
The resin molded body is configured to mechanically hold the first resin molded body.

The sixth step is a step of separating the second exchange mold from the regular mold and taking out the obtained multicolored resin molded body. As a result, a multicolored resin molded body is obtained.

[Effects of the Invention] In the multicolor resin molding method of the present invention and the multicolor resin mold of the present invention, a molded body can be obtained in a form in which the second resin molded body partially surrounds the first resin molded body. For this reason, even if the resins that make up the first resin molded body and the second resin molded body have little affinity, the first resin molded body and the second resin molded body are mechanically bonded, and the two are separated. No other inconveniences will occur. Therefore, it becomes possible to mold multicolored resins such as polyethylene and vinyl chloride resin, which have little affinity with each other, which was previously impossible.

[Example] Next, examples of the present invention will be described.

In the examples, a multicolor resin mold whose main part is shown in cross section in FIGS. 1 and 2 was used. The main components of this type are a regular type 1, a first exchangeable type 2, and a second exchangeable type 3. Note that only the main parts of the first replaceable mold 2 and the second replaceable mold 3 are shown because there is basically no major difference from the replaceable molds of conventional multicolor resin molding molds.

The regular type 1 includes a main body 11, a first core bin 12, a core block 13, a middle plate 14, a push-up plate 15, a mounting plate 16, a hydraulic cylinder 17, and a return pin 1.
8, first push-up pin 19, second core pin 20, second
It is composed of a push-up pin 21, a spacer member 22, and the like. In addition, here, the middle plate 14, the first core pin 1
2. The core block 13 and the hydraulic cylinder 17 are fixed to the mounting plate 16.

The main body 11 has a trapezoidal mold surface, and a through hole 11 a is formed in the center of the main body 11 .
The end surface of 9 and the mold surface of main body 11 are on the same plane. In addition, a through hole 1 is also provided in the runner groove 11b of the main body.
1c is formed, and the second push-up pin 21 is inserted therein. The first push-up pin 19 is for pushing out the molded multicolor resin molding, and the second push-up pin 21 is for pushing out the runner part. Both push-up pins 19, 21 and return pin 18 are connected to push-up plate 1.
5 with a presser plate 151.

Furthermore, the main body 11 has a through hole 11 for a core pin.
d, 11e are formed. A first core pin 12 is inserted into the through hole 11d, and a second core pin 20 is inserted into the through hole 11e. The first core pin 12 is fixed to the intermediate plate 14 by a pressing plate 141.
Further, the second core pin 20 is configured as a piston of the hydraulic cylinder 17. core block 13
is held slidably in the axial direction in a hole 11f opening on the mold surface side of the main body 11, and is coupled to the middle plate 14 by a plurality of engagement pins 131. Note that a biasing spring 132 in a compressed state is incorporated around each engagement pin 131, and biases the intermediate plate 14 and the main body 11 in a direction that moves them away from each other.

The spacer member 22 is held on the middle plate 14 of the regular mold 1. This spacer member 22 is connected to the middle plate 14
A bracket 221 is fixed with a bolt to a hydraulic cylinder 222 fixed to this bracket 221.
, a piston 223, and a wedge-shaped spacer 224. This spacer member 22 has a gap S between the middle plate 14 and the main body 11 as shown in FIG.
When the spacer 224 is formed, the spacer 224 is inserted laterally to ensure a space gap between the intermediate plate 14 and the main body 11.

One end of the return pin 18 is connected to the push-up plate 15
The other end is inserted into the through hole 11g of the main body 11. The head end of the return pin 18 is locked to the shoulder of the through hole 11g, and movement of the push-up plate 15 and push-up pins 19, 21 to the left in FIG. 2 is prevented. A biasing spring 181 is assembled in a compressed state around the return pin 18, and biases the main body 11 and the push-up plate 15 in a direction away from each other.

The multicolor resin mold of this example has the above-described configuration.

Next, a molding method using this mold will be explained.

First, the regular mold 1 is moved to a position opposite the first replaceable mold 2, and the regular mold 1 is pressed against the first replaceable mold 2. FIG. 1 shows a state in which the regular mold 1 and the first replaceable mold 2 are in contact with each other. Here, the biasing force of the biasing spring 132 that biases the main body 11 and the intermediate plate 14 in the direction away from each other is much smaller than the mold clamping force of the molding machine.
The gap S between the middle plate 14 and the main body 11 is maintained at zero. The first resin is injected from the gate 201 formed in the first exchangeable mold 2 into the cavity-a1 formed by the contact between the regular mold 1 and the first exchangeable mold 2, and the first resin molded body M is molded. .

Thereafter, the first replaceable mold 2 and the regular mold 1 are separated, and the regular mold 1 is clamped with the second replaceable mold 3 shown in FIG. Specifically, the regular mold 1 is driven toward the left in FIG. 1 relative to the first exchangeable mold 2, and then driven in a direction substantially perpendicular to this driving direction and pressed against the second exchangeable mold 3. At this time, during the mold opening operation of the molding machine, a gap S is formed between the main body 11 of the regular mold and the intermediate plate 14 due to the biasing force of the biasing spring 132. As a result, the first core pin 12 and the core block 13 move relative to the main body 11 of the regular type 1, and the first core pin 1
2 and the core block 13 are moved back by a gap S with respect to the main body 11. As a result, a columnar space S1 and a space S2 surrounding the outer periphery of the first resin molded body M are formed between the first resin molded body M and the respective tip surfaces of the first core pin 12 and core block 13. At the same time, the second core pin 20 is driven to the left in FIG. 1 to open the gate 3b for second resin molding. Next, the piston 223 of the spacer member 22 protrudes,
The spacer 224 is driven upward in FIG.
Spaces S1 and S2 are retained. In this state, hydraulic pressure is again applied to the mold clamping cylinder of the molding machine, and the main body 11 of the regular mold 1 is pressed against the second exchange mold 3 via the intermediate plate 14 and the spacer 224 by the mold clamping force of the molding machine. As a result, the regular mold 1 and the second exchangeable mold 3 are clamped. A second cavity a2 is then formed between the two.

Next, the runner 3a and gate 3b of the second exchange type 3
and the second core pin 2 by the hydraulic cylinder 17.
Through hole 11e created by drawing in 0
The second resin is injected through the space, and the second resin molded body N is molded. This causes the second resin to
While filling the cavity a2, the first resin molded body M
The first resin molded body M is mechanically held by going around into the spaces S1 and S2 behind the first resin molded body M.

After this, the second exchange type 3 and the regular use type 1 are separated,
Spacer 224 of spacer member 22 retreats.
After this, the obtained multicolored resin molded body is pushed up onto the plate 1.
5 is pushed up to protrude the first push-up pin 19, separated from the conventional mold 1, and removed from the mold surface of the conventional mold 1, thereby obtaining a multicolored resin molded body.

In this example, ABS was used as the first resin and vinyl chloride resin was used as the second resin. Although almost no adhesiveness was observed between the first resin molded body M and the second resin molded body N formed of the respective resins, the second resin molded body M that wrapped around the rear of the first resin molded body M
The first resin molded body M and the second resin molded body N were integrally fixed by the resin molded body N, and there was no fear of separation.

[Brief explanation of drawings]

1 and 2 are sectional views of the main parts showing a part of the mold and the molding state of this example, and FIG. 1 is a main part showing the state where the regular mold and the first exchange mold are in contact with each other. A sectional view and FIG. 2 are principal part sectional views showing a state in which the regular type and the second replacement type are in contact with each other. 1... Regular type, 2... First replacement type, 3... Second
Replaceable type, 11... Main body, 12... First core pin,
13... Core block, 14... Middle plate, 15...
Push-up plate, 16... Mounting plate, 17... Hydraulic cylinder, 22... Spacer member, M... First molded body, N... Second molded body, S, S1, S2... Space.

Claims (1)

[Claims] 1. A regular use comprising a main body constituting a main part, and a movable body fixedly held to the main body at least at a first position and a second position of the main body and forming a part of the mold surface. Using a multi-colored resin molding mold consisting of a mold and at least two first exchangeable molds and a second exchangeable mold that contact the regular mold and form different first and second cavities, first, the regular use mold is formed. a first step of abutting the regular mold and the first replaceable mold while the movable body of the mold is fixed at the first position of the main body; The first cavity is filled with a first resin, and at least one
A second step of forming a first resin molded body having through-holes at certain locations, separating the first exchangeable mold from the regular mold, and then moving the movable body of the regular mold to the second position of the main body. a third step of moving and separating a part of the mold surface of the regular mold that has formed the first resin molded body from the first resin molded body; and a fourth step of bringing the second exchange mold into contact with the regular mold. step, injecting air from the regular mold side of the first resin molded body into a second cavity formed by at least a mold surface separated from the first molded body of the regular mold and a mold surface of the second exchangeable mold. Filling the second resin through the through hole,
a fifth step of integrally forming a second resin molded body with the first resin molded body to form a multicolored resin molded body; separating the second exchangeable mold from the conventional mold; and the obtained multicolored resin; A multicolor resin molding method, characterized in that a sixth step of taking out a molded body is sequentially performed. 2. A multi-colored mold made up of a regular mold that constitutes one of the split molds, and at least two first and second replaceable molds that come into contact with the regular mold and form different first and second cavities, respectively. In the resin molding mold, the regular mold has a main body constituting its main part, and when the regular mold is in contact with the first exchangeable mold, it is fixed at a first position of the main body, and is fixed to the second exchangeable mold. a movable body fixed at a second position of the main body when the regular mold is in contact with the first exchange mold, and the movable body slides within the main body, and when the regular mold is in contact with the first exchange mold. One end of the mold is in contact with the mold surface of the first exchangeable mold, and when the regular mold is in contact with the second replaceable mold, it retreats into the main body to form a through hole communicating with the second cavity inside the main body. at least one sliding member to be formed, at least a portion of the second cavity is formed closer to the regular mold than the first resin molded body, and the second resin is in the second cavity. 1. A multicolor resin molding mold, characterized in that a first resin molded body obtained by filling and molding a first resin into one cavity is filled from the conventional mold side through the through hole. 3. The second position of the movable body is located at a position retreating from the first position with respect to the main body, and the first resin molded body formed between the regular mold and the first exchange mold is The multicolor resin mold according to claim 2, which is partially held by the main body. 4. The second position of the movable body is in a position advanced relative to the main body from the first position, and the first resin molded body is formed between the regular mold and the first exchange mold. 3. The multicolor resin mold according to claim 2, wherein the mold is partially held by the movable body.