JPH03184823A - Cooling method in injection molding - Google Patents

Abstract

PURPOSE:To enhance cooling speed by largely taking a cooling area and to uniformize the cooling of a molded product by forming an empty part having a slide member fitted therein in the vicinity of the cavity in a mold main body and moving the slide member in the direction separating from the cavity at the time of the cooling of an injection molded product to fill the empty part with a cooling medium. CONSTITUTION:At the cooling time of an injection molded product, the cooling medium from a compressor 13 is sent into an empty part 4 from the first cooling medium access port 6 through a change-over valve 14 and a slide member 5 is moved in the direction separating from a cavity 3 by the pressing force due to the cooling medium. Since the second cooling medium access port 7 is allowed to communicate with a suction pump 10 through a change-over valve 9 at this time, sucking action is performed from the second cooling medium access port 7 to promote the movement of the slide member 5. The empty part 4 is filled with the cooling medium on the side of the cavity 3 to cool the injection molded product 20. During the filling with the cooling medium, a vacuum drawing hole 8 is allowed to communicate with the suction pump 10 through the change-over valve 9 and the cooling medium is circulated through the empty part 4. Since the area of the empty part 3 can be taken so as to become larger than that of the cavity 3, a cooling area becomes large.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a cooling method in injection molding.

(Prior art) A conventional cooling method in injection molding involves forming a circular or semicircular channel in the mold body, and injecting water, water, etc. into this channel.
By flowing a refrigerant such as oil, heat was removed from the injection molded product.

(Problem B to be solved by the invention) However, in the case of forming a refrigerant flow path in a mold as described above, problems with the strength, structure, and processing of the mold affect the thickness and thickness of the flow path. There is a problem in that there are restrictions on the position where the flow path is provided.

Further, this has the problem that the cooling rate is slow and the injection molded product is not cooled uniformly.

An object of the present invention is to solve the above-mentioned conventional problems.

That is, an object of the present invention is to provide a cooling method for injection molding that can increase the cooling area, improve the cooling rate, and uniformly cool an injection molded product.

(Means for Solving the Problems) In order to solve the above problems, the present invention provides a cavity in one mold body or both mold bodies of an injection molding machine having a male mold and a female mold. A cavity in which a slide member is fitted is formed nearby, and when the injection molded product is cooled, the slide member is moved away from the cavity by the pressing force of the refrigerant, and the cavity side of the cavity is filled with refrigerant. During non-cooling, the slide member is moved toward the cavity within the space to push the refrigerant away from the cavity.

(Function) When cooling an injection molded product, the sliding member is pushed by the pressing force of the refrigerant to the opposite side of the cavity in the cavity, and the cavity side of this cavity is filled with refrigerant to cool the injection molded product. Cooling.

As a result, the cooling area can be increased and the entire surface of the cavity side can be cooled, so that the cooling rate can be improved and the injection molded product can be cooled uniformly.

On the other hand, during non-cooling, the slide member is moved toward the cavity in the cavity to push the refrigerant to C away from the cavity in the cavity. As a result, no trouble occurs because the raw material for the injection molded product is not cooled while it is being used.

(Example) Hereinafter, a cooling method in injection molding according to the present invention will be explained based on the same.

Fig. 1 is a vertical cross-sectional view showing a mold and a female mold used to carry out the cooling method for injection molding according to the invention; ■■ line cross section,
Figure 3 is a circuit diagram of a refrigerant for cooling the injection molded product within the mold, and Figures 4 to 7 show the refrigerant introduction process and refrigerant extrusion for cooling the injection molded product within the mold body. It is an explanatory diagram showing a process.

First, each mold body in a molding machine for implementing a cooling method in injection molding will be explained based on FIGS. 1 and 2.

A cavity 4.4 is provided near the cavity 3 in the female mold body 1 and the male mold body 2.

Slide members 5 are respectively fitted into the cavities 4.4.

A first refrigerant inlet/outlet hole 6 is provided through one side wall 41 forming the cavity 4, and a second refrigerant inlet/outlet hole 7 is provided through the other side wall 42, and an upper side wall 43 closer to the − side wall 4J. A vacuum hole 8 is provided therethrough.

The first refrigerant inlet/outlet hole 6, the second refrigerant inlet/outlet hole 7, and the vacuum hole 8 described above are in communication with a switching valve 9, as shown in FIG.

Furthermore, this switching valve 9 is connected to the suction pump loL,
This suction pump 1o is connected to a tank 11.

This tank 11 is connected to a temperature device 12 that adjusts the temperature of the refrigerant, and this temperature device 12 is connected to a compressor 13.

This compressor 13 is connected to a switching valve 14 different from the one described above, and this switching valve 14 is connected to the first refrigerant inlet/outlet hole 6 and the second refrigerant inlet/outlet hole 7 described above.

Next, the injection molded product 20 molded by the above molding machine
(See FIG. 1) The process of cooling with a refrigerant during cooling and the process of pushing out this refrigerant when not being cooled will be explained based on FIGS. 4 to 7.

When the raw material for the injection molded article 20 is injected into the mold body 1.2, the slide member 5 is in the position shown in FIG. 4 in the cavity 4.

That is, the slide member 5 is arranged on the cavity 3 side within the empty space 4.

Next, when the injection molded product 20 is cooled, the slide member 5 moves as shown in FIG. 5 and is placed in the empty space 4 at the position shown in FIG. 6.

That is, refrigerant from the compressor 13 is sent into the cavity 4 from the first refrigerant inlet/outlet hole 6 via the switching valve 14, and due to the pressing force of this refrigerant, the slide member 5 is moved away from the cavity 3 side, as shown in the figure. to the left. At this time, the second refrigerant inlet/outlet hole 7 is connected to the suction pump I via the switching valve 9.
Since it is electrically connected to O, a suction action is performed from the second refrigerant inlet/outlet hole 7, and the movement of the slide member 5 is facilitated.

When the state shown in FIG. 6 is reached, the cavity 3 side in the empty space 4 is filled with a refrigerant, and the injection molded product 20 is cooled. During this refrigerant filling, the vacuum hole 8 is connected to the suction pump 10 via the switching valve 9, so that the refrigerant is circulated through the cavity 4.

After cooling the injection molded product 20, the mold body 1.2
is opened and the injection molded product 20 is taken out, and the mold body 1.2 is closed again to be in the state shown in FIG. The state shown in the figure changes to the state shown in FIG.

That is, the refrigerant whose temperature is adjusted by the temperature device is sent from the compressor 13 to the cavity 4 through the second refrigerant inlet/outlet hole 7 via the switching valve 14, and the slide member 5 is moved to the cavity 3 side in the cavity 4. will be moved. At this time, the first refrigerant inlet/outlet hole 6 is connected to a suction pump 10 via a switching valve 9, and performs a suction action to facilitate movement of the slide member 5.

As described above, when cooling the injection molded product 20, the slide member 5 is pushed to the opposite side of the cavity 3 in the cavity 4 by the pushing force of the refrigerant, and the refrigerant is supplied to the cavity 3 side in the cavity 4. After filling, the injection molded product 20 is cooled.

Since the space 4 can be made as large as or larger than the area of the cavity 3, the cooling area becomes large.

This can improve the cooling rate and uniformly cool the injection molded product 20.

On the other hand, when the material is not cooled, the slide member 5 is moved toward the cavity 3 in the cavity 4 to push the refrigerant away from the cavity 3 in the cavity 4. Avoid cooling. Therefore, the bottom shape is not affected.

Incidentally, in the above embodiment, the hollow portion 4 is connected to both mold bodies 1.
．． Although the hollow part 4 is provided in the mold body 1.2, the hollow part 4 is not limited to this, and the hollow part 4 may be provided in either one of the mold bodies 1.2.

(Effects of the Invention) As explained above, according to the present invention, it is possible to increase the cooling area for the injection molded product in the cavity of the mold, and to improve the cooling rate. This has the effect of uniformly cooling the product.

[Brief explanation of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of a male mold and a female mold used for carrying out the cooling method in injection molding according to the present invention, and FIG. A cross-sectional view, FIG. 3 is a circuit diagram of a refrigerant for cooling an injection molded product within a mold, and FIGS. 4 to 7 show a process of introducing a refrigerant to cool an injection molded product within the mold body. It is an explanatory view showing a refrigerant extrusion process. 1.2...Mold body 3...Cavity 4...Empty part 5...Slide member 20...Injection molded product

Claims (1)

[Claims] 1) In an injection molding machine having a male mold and a female mold, a cavity is formed in the vicinity of the cavity in one mold body or both mold bodies to cool the injection molded product. At times, the slide member is moved away from the cavity by the pressing force of the refrigerant to fill the cavity side of the cavity with refrigerant, while when not cooling, the slide member is moved toward the cavity side of the cavity to fill the cavity side with the refrigerant. A cooling method in injection molding characterized by extruding the material away from the cavity.