JP2004155098A - Heating and cooling system for mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating and cooling system for a mold which rapidly discharges a cooling medium at the time of changeover from a cooling process to a heating process and shortens the temperature rising time of the mold. <P>SOLUTION: In the heating and cooling system for the mold, two kinds of heating and cooling media having different temperatures are changed over to be sent to the medium passage in the mold 100 to repeat the heating process, molding process and cooling process of the mold 100. The heating and cooling system has a changeover valve unit 50, which performs the changeover of cooling for passing the cooling water from a cooling unit 30 through the mold 100 to circulate the same to the cooling unit 30 and the changeover of the supply of steam from a heating unit 1 to the mold 100 and the inflow of the steam flowing out of the mold 100 to the cooling unit 30, and a pressure air supply means for sending air to the medium passage in the mold 100 in connection with the changeover from the cooling process to the heating process due to the changeover valve unit 50. When the cooling process is changed over to the heating process, heating steam and air are sent to the medium passage in the mold 100 at the same time to forcibly discharge moisture remaining in the medium passage. <P>COPYRIGHT: (C)2004,JPO

Description

TECHNICAL FIELD OF THE INVENTION
The present invention relates to a heating and cooling system for a mold for molding a plastic product or the like.
[Prior art]
2. Description of the Related Art Conventionally, in a mold for molding a plastic product or the like, two types of media having different temperatures for heating and cooling are supplied to the mold in accordance with a heating and cooling process, and heating, molding, and molding of the mold are performed. A series of steps of cooling and removing the molded product are performed.
[Problems to be solved by the invention]
However, conventionally, when two types of mediums (for example, steam and cooling water) are flown into a medium path in a mold or a connecting pipe line to the mold by switching valves, the two mediums having different temperatures are mixed. However, there is a problem that a time loss occurs in the heating and cooling process.
For example, when switching from the mold cooling step to the heating step, even if steam for heating is sent to the medium path and the connection pipe in the mold, the steam is supplied to the cooling water remaining in the medium path and the connection pipe. Are mixed, and as a result, the calorific value of the steam is deprived, and the time for raising the temperature of the mold is prolonged.
Accordingly, the present invention provides a mold heating / cooling system capable of quickly discharging a cooling medium, particularly when switching from a cooling step to a heating step, and shortening a mold heating time. The purpose is.
[Means for Solving the Problems]
In order to solve the above-mentioned problems, a heating and cooling system for a mold according to the invention according to claim 1 provides a medium path in a mold for heating and cooling at two different temperatures according to a heating and cooling process. In the mold heating / cooling system that repeats the mold heating step, molding step, and cooling step by switching to the heating step, when switching from the cooling step to the heating step, the steam and pressure for heating pass through the medium path in the mold. It is characterized by sending air and forcibly discharging water remaining in the medium path.
The heating / cooling system for a mold according to the second aspect of the present invention provides a heating / cooling system in which two types of media having different temperatures for heating and cooling are switched to a medium path in the mold and sent, and the mold is cooled. In a mold heating / cooling system in which a heating step, a molding step, and a cooling step are repeated, a cooling switch in which cooling water from a cooling unit is circulated to the cooling unit through a mold, and a steam mold from the heating unit. And a switching valve unit for switching the supply of steam to the cooling unit and the flow of steam flowing out of the mold, and the medium path in the mold in conjunction with the switching from the cooling step to the heating step by the switching valve unit. Pressurized air supply means for sending pressurized air to the mold, and when switching from the cooling step to the heating step, simultaneously sends steam for heating and pressurized air to the medium path in the mold and remains in the medium path. It is characterized in that it has to be forcibly ejected minute.
According to the present invention, particularly at the time of switching from the cooling step to the heating step, heating steam and pressurized air are simultaneously sent to the medium path in the mold (purge operation), and water remaining in the medium path is forcibly discharged. Therefore, the time required for the mold to rise to a predetermined temperature can be shortened.
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
FIG. 1 shows a heating / cooling system for a mold 100 according to an embodiment of the present invention. The heating / cooling system includes a heating unit 1, a cooling unit 30, and a switching valve unit 50.
The heating unit 1 makes the raw water softened by a water softener 21, and further supplies a boiler 20 after injecting a medicine such as a preservative by a chemical injecting device 22, and switches the valve unit 50 from the discharge valve 23 as steam in the boiler 20. It is configured to supply to.
The cooling unit 30 guides the cooling water supplied to the cooling water supply port to a cooling tower (or chiller) 31, and further cools the cooling water (water temperature of 10 ° C. to ordinary temperature) in the cooling tower 31 by a pump 32. The water is supplied to the switching valve unit 50 through a cooling water discharge port. The cooling water returned from the switching valve unit 50 flows in from the cooling water return port, and is sprayed from the upper part of the cooling tower 31 into the cooling tower 31 to exchange heat.
The switching valve unit 50 includes four switching valves 71, 72, 73, and 74, each of which is opened and closed by air control.
That is, the switching valve unit 50 allows the cooling water from the cooling water discharge port of the cooling unit 30 to flow into the pump 76 from the cooling water receiving port, increases the pressure by the pump 76, and further switches the manifold 61 through the switching valve 71. Through the mold 100.
The cooling water circulated through the mold 100 is guided through the manifold 62 to the cooling water discharge port via the switching valve 72, and flows into the cooling water return port of the cooling unit 30. The switching valve 73 and the silent reducer 75 are connected between the side and the outlet side of the switching valve 72, and the silent reducer 75 is configured to allow the steam from the outlet side of the manifold 62 to flow into the silent reducer 75.
Air (pressurized air) for controlling the opening and closing of the four switching valves 71 to 74 is supplied from an air source (not shown) via an air filter 56 and an air regulator 57.
In addition, air is supplied from an air source (not shown) to a pipe on the outlet side of the switching valves 71 and 74 via a cock 58 and a stop valve 59 constituting a compressed air supply means via an air filter 56 and an air regulator 57. It is possible.
The temperature of the mold 100 is detected by the temperature sensor 101 and sent to a control panel (not shown).
FIG. 2 is an explanatory diagram of the open / close state of the four switching valves 71 to 74 during standby, heating, and cooling.
Next, the operation of the heating and cooling system according to the present embodiment will be described with reference to FIG.
(During standby)
During standby, as shown in FIG. 2, only the switching valve 73 is controlled to be open, and the other three switching valves 71, 72, 74 are controlled to be closed.
At this time, the cooling water from the cooling unit 30 returns to the cooling unit 30 via the pump 76, the switching valve 73, and the silent reducer 75, and enters a circulating state. Further, the steam from the heating unit 1 is not supplied to the mold 100 because the switching valve 74 is closed.
(When the mold 100 is cooled)
At the time of molding and injection in the mold 100, the mold 100 is kept at a predetermined temperature (usually high temperature), and based on a detection signal from the temperature sensor 101, at a predetermined timing, as shown in FIG. The switching valves 73 and 74 are controlled to be closed and the switching valves 71 and 72 are controlled to be opened to perform rapid cooling of the mold 100 with cooling water.
That is, by setting the switching valves 73 and 74 to the closed state and the switching valves 71 and 72 to the open state, the cooling water is supplied to the pump 32, the pump 76, the switching valve 71, the manifold 61, the mold 100, the manifold 62, Circulation of the cooling water to the valve 72, the cooling tower 31, and the pump 32 is performed, and rapid cooling of the mold 100 is performed.
After the mold 100 is cooled and opened to take out the molded product, a series of operations of moving to the above-described heating operation and flowing high-temperature steam to the mold 100 to raise the temperature are repeated. .
(When heating the mold 100)
In this case, as shown in FIG. 2, the switching valves 73 and 74 are controlled to be open, and the switching valves 71 and 72 are controlled to be closed. At this time, the cooling water from the cooling unit 30 returns to the cooling unit 30 via the pump 76, the switching valve 73, and the silent reducer 75, and enters a circulating state.
The steam generated by the heating unit 1 passes through the switching valve 74, the manifold 61, passes through the mold 100, heats the mold 100 to a predetermined temperature, and further passes through the manifold 62, the silent reducer 75, and the cooling water. Into the circulation path. When the switching valves 73 and 74 are controlled to be open and the switching valves 71 and 72 are controlled to be closed and heating of the mold 100 is started, the cock 58 and the stop valve 59 are also controlled to open in conjunction with each other. Then, air (pressure air) is supplied from the outlet side of the switching valves 71 and 74 to the mold 100 via the manifold 61 together with steam, and is sent to the medium passage in the mold 100 (purge operation). The cooling water remaining in the medium path is forcibly pushed out from the manifold 61 to the flow path to the silent reducer 75.
FIG. 3 shows a timing chart of supply and stop of the cooling water, steam, and air in the operation of the present embodiment.
By the above-described operation of the present embodiment, the cooling water remaining from the mold 100 is quickly discharged, particularly when switching from the cooling step to the heating step, and the time required for the mold 100 to rise to a predetermined temperature is shortened. can do.
The setting of the switching timing and time of each of the switching valves 71 to 74 described above can be freely performed by using a timer or a setting operation on a control panel according to a user's request and conditions. It is.
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, especially when switching from a cooling process to a heating process, the cooling water which remains from a metal mold | die is quickly performed, and the metal mold | die which can shorten the temperature rise time to a predetermined temperature of a metal mold | die can be shortened. Can be provided.
[Brief description of the drawings]
FIG. 1 is a piping diagram showing a heating and cooling system for a mold according to an embodiment of the present invention.
FIG. 2 is an explanatory diagram showing an open / closed state of a switching valve according to the present embodiment.
FIG. 3 is a timing chart of supply and stop of cooling water, steam, and air in the operation of the present embodiment.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heating unit 20 Boiler 21 Water softener 23 Discharge valve 30 Cooling unit 31 Cooling tower 32 Pump 50 Switching valve unit 56 Air filter 57 Air regulator 58 Cock 59 Stop valve 61 Manifold 62 Manifolds 71 to 74 Switching valve 75 Silent reducer 76 Pump 100 Mold 101 Temperature sensor

Claims (2)

A heating / cooling system for a mold that repeats the heating, molding, and cooling steps of the mold by switching the medium at two different temperatures, heating and cooling, to the medium path in the mold according to the heating / cooling process. At
A heating and cooling system for a mold, wherein when switching from the cooling step to the heating step, steam and pressurized air for heating are sent to a medium path in the mold, and moisture remaining in the medium path is forcibly discharged. . A heating / cooling system for a mold that repeats the heating, molding, and cooling steps of the mold by switching the medium at two different temperatures, heating and cooling, to the medium path in the mold according to the heating / cooling process. At
Cooling switching in which cooling water from the cooling unit is circulated to the cooling unit through the mold, supply of steam from the heating unit to the mold, and switching of steam flowing out of the mold into the cooling unit. A switching valve unit for performing
Pressure air supply means for sending pressurized air to a medium path in the mold in conjunction with switching from a cooling step to a heating step by the switching valve unit,
Has,
When switching from the cooling step to the heating step, heating steam and pressurized air are simultaneously sent to the medium path in the mold, and water remaining in the medium path is forcibly discharged. Heating and cooling system.

Images