JP2010188678A - Mold heating/cooling system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mold heating/cooling system which can enhance manufacturing efficiency at a low cost by shortening a finished product cycle time while preventing a weldline from being generated by alternate mold heating and cooling operation performed by switching a hot water circulation circuit and a cold water circulation circuit. <P>SOLUTION: The mold heating/cooling system for a mold 1 in the injection molding process of filling the mold 1 with a molten raw material to manufacture various kinds of finished products includes a hot water circulation circuit A and a cold water circulation circuit B passing through the mold 1 and including common lines c1 and c2. The hot water circulation circuit A or the cold water circulation circuit B is selected by switching means (on/off-valves V1 to V6). Hot water or cold water is selectively allowed to flow to the mold 1 through the common lines c1 and c2 from either of the circulation circuits A and B to heat or cool the mold 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a heating / cooling system for a mold in injection molding in which various raw materials are manufactured by filling a molten raw material into a mold.

  For example, in resin injection molding, as shown in FIG. 3A, the molding space 1a formed by the cavity side mold 1A and the core side mold 1B is filled with the molten resin 10 by a molding machine. When the molten resin 10 is cooled and solidified, as shown in FIG. 3B, the cavity side mold 1A and the core side mold 1B are opened and the product (resin molded product) W is taken out.

  By the way, in such injection molding, generation of a weld line becomes a problem. This weld line is generated at the portion where the tips of the resin that have flowed from different directions when the molten resin is filled in the molding space of the mold, and causes the appearance of the product to deteriorate.

  In order to prevent the occurrence of the weld line, the mold temperature may be raised. For example, in Patent Document 1, a heating body (heater) is installed inside the mold, and the mold is moved by the heating body during molding. Proposals for heating to high temperatures have been made. When the mold is heated in this way, it takes a long time for the mold to cool and take out the product, and the product cycle time becomes longer and the production efficiency decreases, so the vicinity of the heating element inside the mold A cooling passage is formed in the mold, and the mold after heating is cooled by flowing cold water through the cooling passage after molding.

  In addition, regarding the heating and cooling of the mold, various proposals have been made in Patent Documents 2 and 3, for example.

JP 2003-033957 A JP 2007-118213 A JP 2007-223168 A

  Conventionally, as shown in FIG. 3, a supply line a and a recovery line b are respectively connected to the cavity mold 1A and the core mold 1B, and the cavity mold 1A is connected to the supply line a and the recovery line b. And a method of heating or cooling the cavity mold 1A and the core mold 1B by circulating hot water or cold water through the core mold 1B, respectively.

  However, since only one of heating and cooling can be performed in the above method, there is a problem that either one of prevention of the generation of the weld line or shortening of the cycle time of the product must be sacrificed.

  The present invention has been made in view of the above-mentioned problems, and its intended process is to prevent the occurrence of weld lines by alternately heating and cooling the mold by switching between the hot water circulation circuit and the cold water circulation circuit. On the other hand, an object of the present invention is to provide a mold heating / cooling system capable of reducing the cycle time of a product and improving the production efficiency at a low cost.

  In order to achieve the above object, the invention described in claim 1 is a common system that passes through the mold as a heating / cooling system for the mold in injection molding in which a molten raw material is filled into a mold to produce various products. A hot water circulation circuit and a chilled water circulation circuit are formed respectively, and the hot water circulation circuit or the chilled water circulation circuit is switched by switching means, and hot water or cold water is supplied to the mold from one of them through the common line. The mold is heated and cooled by selectively flowing.

  The invention according to claim 2 is characterized in that, in the invention according to claim 1, it is constituted by an on-off valve provided in the hot water circulation circuit and the cold water circulation circuit.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein at least the hot water circulation circuit is provided with a bypass line for bypassing the mold and circulating the hot water, and an open / close valve is provided in the bypass line. It is characterized by that.

  According to the first aspect of the present invention, the hot water circulating circuit or the cold water circulating circuit is switched by the switching means, and hot water or cold water is selectively flowed from one of them to the mold through a common line to heat the mold. Since it is cooled, it is possible to heat and cool the mold by alternately circulating hot water and cold water to the mold using a common line, and prevent the generation of weld lines by heating the mold. However, by cooling the heated mold with cold water, the cycle time of the product can be shortened, and the production efficiency can be improved at a low cost.

  According to the second aspect of the present invention, the hot water circulation circuit or the cold water circulation circuit can be switched by opening and closing the hot water circulation circuit and the on-off valve provided in the cold water circulation circuit.

  According to the third aspect of the present invention, since the on-off valve of the bypass line provided in the hot water circulation circuit is opened when the mold is cooled, the hot water can be circulated to the hot water circulation circuit by bypassing the mold. Sometimes, continuous operation can be performed without stopping the driving of the water heater or the like.

It is a figure which shows the state at the time of the heating of the heating / cooling system of the metal mold | die which concerns on this invention. It is a figure which shows the state at the time of cooling of the heating / cooling system of the metal mold | die which concerns on this invention. (A) is a figure which shows the metal mold | die at the time of injection molding, (b) is a figure which shows the metal mold | die at the time of product taking-out.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

  FIG. 1 is a diagram showing a heating state of a mold heating / cooling system according to the present invention. FIG. 2 is a diagram showing a cooling state of the heating / cooling system. The heating / cooling system includes a common supply line c1 and a recovery line c2 that pass through the mold 1, and a hot water circulation circuit A, which is a mold used (cavity side mold and core mold). A cold water circulation circuit B is formed. In the present embodiment, the mold 1 has a built-in heater H for heating, and the heater H is connected to a power source (not shown) via a switch S.

  The hot water circulation circuit A is provided with a water heater 2, and the hot water circulation circuit A includes a hot water line a 1 extending from the water heater 2 to the union 3, a hot water line a 2 extending from the union 3 to the union 4, A supply line c1 and a recovery line c2, a hot water line a3 extending from the union 5 to the union 6, and a hot water line a4 extending from the union 6 to the water heater 2 are provided. The hot water line a2 is provided with a check valve V that allows the on-off valve V1 and the flow from the water heater 2 to the mold 1 direction, and the hot water line a3 is provided from the open / close valve V2 and the mold 1 to the water heater 2 direction. A check valve V that allows the flow of hot water is provided.

  The hot water circulation circuit A is provided with a hot water bypass line a5 that connects the union 3 and the union 6, and the hot water bypass line a5 is provided with an on-off valve V3.

  On the other hand, the chilled water circulation circuit B is provided with a chiller (chiller) 7. The chilled water circulation circuit B includes a chilled water line b1 extending from the chilled water device 7 to the union 8, and a chilled water line b2 extending from the union 8 to the union 4. And the common supply line c1 and recovery line c2, a cold water line b3 extending from the union 5 to the union 9, and a cold water line b4 extending from the union 9 to the water cooler 7. The chilled water line b2 is provided with a check valve V that allows the on-off valve V4 and the flow from the chiller 7 to the mold 1 direction, and the chilled water line b3 is provided from the on-off valve V5 and the mold 1 to the chiller 7 direction. A check valve V is provided to allow the flow of air.

  The cold water circulation circuit B is provided with a cold water bypass line b5 that connects the union 8 and the union 9, and the cold water bypass line b5 is provided with an on-off valve V6.

  In the present embodiment, the on-off valves V1 to V6 are all constituted by electromagnetic valves.

  Next, heating and cooling of the mold 1 by the heating / cooling system configured as described above will be described.

  First, at the time of molding, hot water circulates through the hot water circulation circuit A and the mold 1 is heated by the hot water, and the switch S is turned on and the mold 1 is heated by the heater H. That is, when the mold 1 is heated, as shown in FIG. 1, the switch S is turned on to energize the heater H, and the on-off valves V1 and V2 provided in the hot water circulation circuit A are opened to open and close the on-off valve V3. Is closed, the on-off valves V4 and V5 provided in the cold water circulation circuit B are closed, and the on-off valve V6 is opened.

  In the present embodiment, the water heater 2 and the water cooler 7 are continuously operated, and in the hot water circulation circuit A, hot water heated to a predetermined temperature by the water heater 2 is supplied in common through the hot water lines a1 and a2. It is supplied from the line c1 to the mold 1 and used for heating the mold 1. At the same time, when the switch S is turned on and the heater H is driven as described above, the mold 1 is heated by the heater H.

  The hot water that has heated the mold 1 is recovered from the common recovery line c2 to the water heater 2 via the hot water lines a3 and a4, and is heated to a predetermined temperature in the water heater 2 to repeat the above circulation. Since the mold 1 is heated by the hot water circulating in the circulation circuit A and the heater H, the generation of the weld line is prevented. At this time, since the on-off valve V6 provided in the chilled water bypass line a5 of the chilled water circulation circuit B is open, the chilled water cooled to a predetermined temperature by the chiller 7 is constituted by the chilled water lines b1, b5, and b4. Circulates through the cold water bypass circuit B1. Therefore, the water cooler 7 can be continuously operated while the mold 1 is heated with warm water during molding.

  Then, after the molten resin is filled in the molding space (not shown) in the mold 1, the switch S is turned off to cut off the energization of the heater H, and cold water circulates in the cold water circulation circuit B so that the mold 1 is cooled by cold water. That is, when the mold 1 is cooled, as shown in FIG. 2, the on-off valves V4, V5 provided in the cold water circulation circuit B are opened, the on-off valve V6 is closed, and the on-off valves provided in the hot water circulation circuit A are closed. V1 and V2 are closed, and the on-off valve V3 is opened.

  Thus, in the cold water circulation circuit B, the cold water cooled to a predetermined temperature by the water cooler 7 is supplied from the common supply line c1 to the mold 1 through the cold water lines b1 and b2, and the mold 1 Provided for cooling. And the cold water which cooled the metal mold | die 1 is collect | recovered from the common collection | recovery line c2 to the water cooler 7 via the cold water lines b3 and b4, is cooled to predetermined temperature in the water cooler 7, and repeats the above circulation. Since the mold 1 is cooled by the cold water circulating through the cold water circulation circuit B, the molten resin in the mold 1 is rapidly cooled, the cycle time of the product is shortened, and the production efficiency is increased. At this time, since the on-off valve V3 provided in the hot water bypass line a5 of the hot water circulation circuit A is open, the hot water heated to a predetermined temperature by the water heater 2 is constituted by the hot water lines a1, a5, and a4. The hot water bypass circuit A1 is circulated. Therefore, it is possible to continuously operate the water heater 2 without stopping it while the mold 1 is cooled by cold water after molding.

  As described above, according to the heating / cooling system of the present invention, the hot water circulation circuit A or the cold water circulation circuit B is switched by the on-off valves V1 to V6 serving as switching means, and the common supply line c1 and the recovery are connected from one of them. Since the mold 1 is heated and cooled by selectively flowing hot water or cold water to the mold 1 via the line c2, the hot water and the cold water are supplied to the mold 1 using the common supply line c1 and the recovery line c2. By alternately circulating, the mold 1 can be heated and cooled, and by heating the mold 1 with warm water, the heated mold 1 is cooled with cold water while preventing the generation of weld lines. Product cycle time can be shortened and production efficiency can be improved at low cost.

  In addition, although the above demonstrated the form which applied this invention to the resin molding metal mold | die, this invention is applicable similarly also to the metal mold | die used for injection molding other than resin molding. Of course.

DESCRIPTION OF SYMBOLS 1 Mold 2 Water heater 1-6 Union 7 Chiller 8, 9 Union A Hot water circulation circuit B Chilled water circuit A1 Hot water bypass circuit B1 Chilled water bypass circuit a1-a4 Hot water line a5 Hot water bypass line b1-b4 Chilled water line b5 Chilled water bypass Line c1 Common supply line c2 Common recovery line H Heater S Switch V Check valve V1 to V6 On-off valve

Claims (3)

A heating / cooling system for the mold in injection molding for manufacturing various products by filling a molten raw material into a mold,
A hot water circulation circuit and a cold water circulation circuit are respectively formed including a common line passing through the mold, and the hot water circulation circuit or the cold water circulation circuit is switched by a switching means, and one of them is passed through the common line to A mold heating / cooling system, wherein hot or cold water is selectively passed through the mold to heat and cool the mold.   2. The mold heating / cooling system according to claim 1, wherein the switching means includes an on-off valve provided in the hot water circulation circuit and the cold water circulation circuit.   3. The mold heating / cooling according to claim 1, wherein a bypass line for bypassing the mold and circulating the hot water is provided at least in the hot water circulation circuit, and an open / close valve is provided in the bypass line. system.

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