KR20170040627A - Injection molding apparatus and Method for controlling injection molding apparatus - Google Patents

Abstract

There is provided an injection molding apparatus having a structure in which temperature maintenance and adjustment of a mold is easy and maintenance is easy, and a control method for controlling such an injection molding apparatus. The injection molding apparatus is provided with a mold section in which a flow path through which a heat medium fluid flows, a first reservoir tank disposed at the front end of the mold section and connected to the flow path to supply the heat medium fluid to the flow path, a first reservoir tank disposed between the first reservoir tank and the mold section, And a second reservoir tank disposed at a rear end of the mold and connected to the flow path to regulate the pressure of the flow path.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding apparatus and a control method of an injection molding apparatus,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding apparatus and a control method of an injection molding apparatus, and more particularly, to an injection molding apparatus having a structure in which temperature maintenance and adjustment of a mold is easy and maintenance is easy, .

In modern society, which mass-produces and consumes large quantities of products, development of product manufacturing technology is extremely important. Especially, it is necessary not only for the producer but also for the consumer to develop the manufacturing technology which can maintain the high quality without fluctuating the quality of the product even if a plurality of products are produced repeatedly.

The technique of molding a product using a mold is a very useful technique for mass production. It is possible to easily manufacture the product by injection molding method in which the molten material is injected into the mold and the product is made by applying heat or pressure, and the product of complicated shape can be manufactured comparatively easily.

When a product is produced using a mold, the quality of the product may vary depending on the temperature maintained by the molten material in the mold. That is, in the case of producing the product by the injection molding method, a technique of maintaining the temperature of the mold properly is indispensable. However, since the temperature of the mold is indirectly controlled by the temperature of the heat medium fluid injected into the mold, it is difficult to control the mold temperature to a desired temperature.

Particularly, when a channel is formed in a mold to inject a heat medium fluid or the like, there is a problem that the fluid temperature does not rise as desired due to the pressure drop inside the pipe, or the temperature can not be maintained at a temperature suitable for product production. In order to solve such a problem, in the case of closing a part of the pipe, the fluid is not circulated, so that the mold is damaged or it is difficult to clean the closed pipe.

Further, by applying a fluid pump for circulation to circulate a fluid medium (including water or other fluids) in a liquid state in a conventional pipeline, there has been a great difficulty in maintenance such as pump failure at high temperature and leakage from the packing. In addition, since the heated heat medium fluid reaches a saturated state at a high temperature and vaporization may occur, it is necessary to pressurize the fluid to supply the fluid in a liquid state, but a pressure drop occurs at the inlet of the fluid pump to generate bubbles, There is a problem that circulation is stopped due to a malfunction.

Further, in the case of heating a mold or the like by circulating a fluid medium, which is a liquid, heat is transferred by sensible heat, so that there is a problem that a temperature difference in the duct occurs if the amount of fluid circulation is insufficient. Therefore, it was necessary to increase the amount of fluid circulation in the conduit in order to solve this problem. As a result, the flow resistance increased due to the fluid mass flow in the cramped pipe and the excessive power consumption due to the increase in the pump work became a serious problem.

In addition, the use of steam as the thermal medium fluid can increase the heat transfer rate and decrease the steam mass flow rate through high vaporization latent heat. However, since a large boiler facility and a long-distance pipeline for steam transportation are required, In particular, problems such as the occurrence of a vapor pressure drop within a long-distance pipe have occurred. That is, in order to raise the temperature of the mold sufficiently, it is necessary to pressurize the interior of the mold or the pipe with a saturated vapor pressure capable of raising the temperature to the temperature, but it has been very difficult to accomplish this with a conventional fluid pump.

Korean Patent No. 10-1265126, (2013.05.16)

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and it is an object of the present invention to provide an injection molding apparatus having a structure in which the temperature of molds can be easily maintained and adjusted and maintenance is easy, And to provide a control method of an injection molding apparatus.

The technical problem of the present invention is not limited to the above-mentioned problems, and another technical problem which is not mentioned can be clearly understood by those skilled in the art from the following description.

An injection molding apparatus according to the present invention includes: a mold unit having a flow path through which a heat medium fluid flows; A first reservoir tank disposed at a front end of the mold unit and connected to the flow path to supply the heat medium fluid to the flow path; A heating unit disposed between the first reservoir tank and the mold unit and heating the heat medium fluid injected into the mold unit; And a second reservoir tank disposed at a rear end of the mold unit and connected to the flow path to adjust a pressure of the flow path.

The pressure of the second reservoir tank may be kept lower than the pressure of the first reservoir tank while the heat medium fluid circulates.

A pressurizing portion for injecting air into at least one of the first reservoir tank and the second reservoir tank to increase the pressure of at least one of the first reservoir tank and the second reservoir tank, And a pressure reducing valve connected to each of the two reservoir tanks.

Wherein the pressurizing portion includes an air compressor, a first injection tube connected between the air compressor and the first reservoir tank, a second injection tube connected between the air compressor and the second reservoir tank, And an injection valve for opening and closing each of the second injection pipes.

A connection channel which is connected between the first reservoir tank and the second reservoir tank and a second reservoir tank which communicates with the first reservoir tank and the second reservoir tank by opening the connection channel, And a connection control valve for disconnecting the first reservoir tank and the second reservoir tank from each other.

And a supply passage connected to the second reservoir tank for supplying the heat medium fluid to the second reservoir tank.

And a sensor unit which is formed in each of the first reservoir tank and the second reservoir tank and includes a water level sensor and a pressure sensor.

The heating unit may include at least one heater, a temperature controller for controlling the temperature of the heater, and a heat exchange channel that is bent at least once through the heater and through which the heating medium fluid flows.

A cooling water supply pipe connected between the heating unit and the mold unit to supply cooling water to the flow channel, a purge gas supply pipe connected between the heating unit and the mold unit to supply the purge gas to the flow channel, And a drain pipe connected between the first reservoir tank and the second reservoir tank.

A control method of an injection molding apparatus according to the present invention is characterized in that a pressure difference is induced between a first reservoir tank connected to a front end of a flow path formed in a mold and a second reservoir tank connected to the rear end, Flowing the heating medium fluid to the second reservoir tank via the second reservoir tank; And changing or maintaining the pressure inside the flow passage through which the heat medium fluid passes by adjusting the pressure of the second reservoir tank.

The pressure of the second reservoir tank may be kept lower than the pressure of the first reservoir tank while the heat medium fluid circulates.

Wherein at least one of the first reservoir tank and the second reservoir tank is provided with a pneumatic pressure to generate a pressure difference between the first reservoir tank and the second reservoir tank or to generate a pressure difference between the first reservoir tank and the second reservoir tank, The pressure of at least one of the tanks can be adjusted.

The first reservoir tank and the second reservoir tank are directly connected to each other so that the pressures of the first reservoir tank and the second reservoir tank are mutually adjusted or the heat medium fluid accommodated in the second reservoir tank is supplied to the first reservoir tank Can supply.

The heat medium fluid is heated between the first reservoir tank and the mold section, and can exchange heat with the mold section while passing through the flow path inside the mold section.

Stopping the flow of the heat medium fluid, cooling the mold section by supplying cooling water to the flow path, and purifying the flow path by supplying purge gas to the flow path.

The injection molding apparatus according to the present invention can easily adjust the pressure of the flow path formed in the mold to change the pressure condition of the heating medium fluid passing through the inside of the flow path and raise the temperature of the heating medium fluid. That is, the temperature of the mold can be easily controlled by regulating the saturation pressure and the saturation temperature by changing the pressure condition easily according to the mold heating temperature, circulating the heating medium fluid in a humid atmosphere, superheated steam, or a liquid state. Therefore, the mold temperature can be maintained at a desired level, so that a high-quality product can be injected.

Particularly, by introducing the pressure difference between the reservoirs with the air pressure and supplying the heat medium fluid, it is possible to very effectively eliminate various disadvantages of the conventional fluid pump application. In addition, it is possible to control the pressure condition in a wide range by the pneumatic method, it is possible to adjust to a saturation pressure reaching a sufficiently high temperature and to heat the mold to a very high temperature.

In addition, the injection molding apparatus according to the present invention has an advantage that the circulation of the fluid passing through the flow path can be smoothly performed, and the cooling and washing of the mold, or other maintenance work can be performed very conveniently.

Further, by using the control method of the injection molding apparatus according to the present invention, it is possible to easily adjust the pressure of the flow path formed in the mold and to change the pressure condition of the heat medium fluid passing through the flow path, The temperature of the fluid can be controlled such as rising or falling. Therefore, the mold temperature can be maintained at a desired level, so that a high-quality product can be injected.

1 is a view conceptually showing a configuration of an injection molding apparatus according to an embodiment of the present invention.
2 is a perspective view of a heating unit of the injection molding apparatus of FIG.
FIGS. 3 to 7 are views showing the operation of the injection molding apparatus of FIG.
8 is a flowchart showing a control method of an injection molding apparatus according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and methods for achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those skilled in the art. To fully disclose the scope of the invention to a person skilled in the art, and the invention is merely defined by the claims. Like reference numerals refer to like elements throughout the specification.

In the present specification, the terms 'shear' and 'rear end' may be distinguished based on the flow direction of the fluid. The 'shear' may refer to the side of the fluid entering or connected to it, and the 'rear end' may refer to the side of the fluid to be drained or the connected part. For example, an inlet side or a connected portion of a fluid flowing device, a component portion, a pipeline, or the like can be expressed by the front end of the device, the component portion, and the pipeline, and the outlet side, It can be expressed as the rear end of the pipeline. Means that they are arranged or connected at the inlet side, and those arranged at the rear end or connected to the front end may be disposed or connected at the outlet side.

Hereinafter, an injection molding apparatus and a control method of the injection molding apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 8. FIG. First, the injection molding apparatus will be described in detail, and then a description will be given in a manner to describe the control method of the injection molding apparatus in detail.

FIG. 1 is a conceptual view of the configuration of an injection molding apparatus according to an embodiment of the present invention, and FIG. 2 is a perspective view of a heating section of the injection molding apparatus of FIG.

1 and 2, an injection molding apparatus according to an embodiment of the present invention includes: (1) a mold unit 30 having a flow path 31 through which a fluid of a heating medium flows; a mold unit 30 disposed at a front end of the mold unit 30; A first reservoir tank 10 connected to the flow path 31 to supply the heat medium fluid to the flow path 31, a first reservoir tank 10 disposed between the first reservoir tank 10 and the mold part 30, And a second reservoir tank 20 disposed at the rear end of the mold part 30 and connected to the flow path 31 to adjust the pressure of the flow path 31. [ .

The injection molding apparatus 1 according to the embodiment of the present invention can raise the temperature of the mold section 30 by injecting the heat medium fluid into the flow path 31 of the mold section 30. [ In particular, the second reservoir tank 20 at the rear end of the mold part 30 can be used to adjust the pressure of the flow path 31 of the mold part 30 so as not to decrease, The pressure condition of the fluid can be easily changed or maintained so as to maintain a higher temperature.

In particular, the injection molding apparatus 1 according to an embodiment of the present invention can change and maintain the pressure of the entire system by using air pressure. That is, the pressure difference between the first reservoir tank 10 and the second reservoir tank 20 is induced by pneumatic pressure, and the flow path of the heat medium fluid connected between the first reservoir tank 10 and the second reservoir 20 tank The internal pressure can be increased very easily. Therefore, it is possible to easily solve problems (such as pressure drop at the fluid pump inlet, pump failure at high temperature, and leakage of packing oil), which are caused by application of the fluid circulation pump in the related art, It is possible to maintain the saturation pressure at a high level so as to be able to reach a sufficiently high temperature.

In the injection molding apparatus 1 according to the embodiment of the present invention, the heat medium fluid flows between the different reservoir tanks (the first reservoir tank and the second reservoir tank) via the flow path 31 of the mold section 30 And is formed to freely circulate. Therefore, the flow path of the heat medium fluid is not blocked or closed at one side, so that the heat medium fluid can smoothly pass through the flow path 31 and can be discharged.

That is, the injection molding apparatus 1 according to the embodiment of the present invention has a structure that can easily control the pressure of the flow path 31 to the second reservoir tank 20 connected to the rear end of the flow path 31, It is not necessary to close one side of the flow path 31 or to connect a separate closed path or the like in order to prevent a pressure drop inside the flow path 31. In this way, the pressure of the flow path 31 can be easily adjusted, 1 structure in which the heat medium fluid easily circulates between the reservoir tank 10 and the second reservoir tank 20 to keep the flow path 31 cleaner and the pressure of the entire system can be changed and maintained by using the air pressure . With this structure, not only the temperature of the mold part 30 can be maintained at a temperature suitable for product molding, but also cooling, cleaning, and other maintenance work of the mold part 30 can be performed very conveniently. Hereinafter, the injection molding apparatus 1 having these features will be described in more detail with reference to the respective drawings.

The first reservoir tank 10 and the second reservoir tank 20 may be formed in the form of a pressure vessel in which the remaining portion except the connection portion such as the pipeline or the flow path is sealed. The first sensor unit 12 and the second sensor unit 22 including the pressure sensor and the water level sensor may be respectively formed in the first reservoir tank 10 and the second reservoir tank 20. [ The first reservoir tank 10 serves to supply the heat medium fluid and the second reservoir tank 20 may serve to recover the supplied heat medium fluid again. The second reservoir tank 20 is capable of recovering the heat medium fluid through a conduit directly connected to the flow path 31 of the metal mold part 30, It can propagate. The pressure inside the flow path 31 can be adjusted so as not to decrease and the pressure condition of the heat medium fluid passing through the flow path 31 can be changed or maintained.

The first reservoir tank 10 is disposed at the front end of the mold part 30 as shown in FIG. 1 and is connected to the flow path 31 of the mold part 30 through the main flow path 60. The main flow path 60 may be formed with valves 601 and 602 for opening and closing one side of the main flow path 60 so that the heating fluid passes through the main flow path 60 and the flow of the heating fluid can be stopped or resumed as needed. The main flow path 60 may be formed as a conduit connected between the first reservoir tank 10 and the mold part 30. [

The second reservoir tank 20 is disposed at the rear end of the mold part 30 and is directly connected to the flow path 31 of the mold part 30 through the pressure control pipe 70. The pressure regulating pipe 70 serves to transfer the pressure of the second reservoir tank 20 to the flow path 31 and serves as a transfer path for transferring the heat medium fluid from the flow path 31 to the second reservoir tank 20 can do. A valve 701 may be formed on the side of the pressure regulating pipe 70 so as to open or close the pressure regulating pipe 70 as required.

The first reservoir tank 10 and the second reservoir tank 20 may be configured to be connected to the pressurization portion 50 to increase the pressure of the reservoir tank. Particularly, the pressurizing unit 50 injects air into at least one of the first reservoir tank 10 and the second reservoir tank 20 so that at least one of the first reservoir tank 10 and the second reservoir tank 20 May be formed to increase the pressure. The pressurizing unit 50 includes, for example, an air compressor 53 for supplying compressed air, a first injection pipe 51 connected between the air compressor 53 and the first reservoir tank 10, an air compressor 53 A second injection pipe 52 connected between the first reservoir tank 20 and the second reservoir tank 20 and a first injection valve 511 connected to the first injection pipe 51 and the second injection pipe 52, An injection valve 521 may be included.

That is, as described above, the pressure difference can be induced between the first reservoir tank 10 and the second reservoir tank 20 by using pneumatic pressure, and the pressure condition of the entire system can be easily changed and maintained. Accordingly, the heat medium fluid circulation system can be configured very easily without applying a fluid pump having a structure such as a conventional liquid state fluid sucked or discharged and circulated.

The first reservoir tank (10) and the second reservoir tank (20) may be formed with a pressure reducing valve for discharging the fluid to the outside and depressurizing the fluid. For example, a first pressure regulating pipe 13 may be formed on one side of the first reservoir tank 10 and a first pressure reducing valve 131 may be connected to open and close the first pressure regulating pipe 13, A second pressure regulating pipe 23 may be formed on one side of the reservoir tank 20 and a second pressure reducing valve 231 may be connected to open and close the second pressure regulating pipe 23. [ Therefore, it is possible to change the internal pressures of the first reservoir tank 10 and the second reservoir tank 20 by adjusting the pressurizing portion 50 and the pressure reducing valves (the first pressure reducing valve and the second pressure reducing valve) .

In particular, the pressure of the second reservoir tank 20 can be kept lower than the pressure of the first reservoir tank 10 while the heat medium fluid circulates. The pressure difference between the first reservoir tank 10 and the second reservoir tank 20 is induced and the pressure inside the flow path 31 formed in the mold part 30 can be controlled so as not to be reduced to the atmospheric pressure or less. The pressure inside the flow path 31 can be raised by the saturated vapor pressure of the heat medium fluid corresponding to the temperature so that the temperature of the mold part 30 is reduced And can be controlled to maintain a high temperature state. This will be described in more detail below.

On the other hand, the first reservoir tank 10 and the second reservoir tank 20 can be configured so that they can be directly used as needed. That is, a connection passage 11 for directly connecting the first reservoir tank 10 and the second reservoir tank 20 is formed and a connection control valve 111 for opening and closing the connection passage 11 is provided, The first reservoir tank 10 and the second reservoir tank 20 are communicated with each other by opening the connection passage 11 or by closing the connection passage 11 to connect the first reservoir tank 10 and the second reservoir tank 20, (20) can be disconnected from each other.

In this case, as shown in FIG. 1, a supply passage 21 for supplying a heat medium fluid to the second reservoir tank 20 is provided to supply the heat medium fluid to the second reservoir tank 20, (10). The supply passage 21 is provided to replenish the vapor-phase heat medium fluid discharged together with air at the time of depressurization. When the valve 211 of the supply passage 21 is opened and closed to supplement the heat medium fluid to the second reservoir tank 20, it is possible to store the fluid together with the recovered heat medium fluid after completion of the circulation, So that it can be distributed collectively between the first reservoir tank (10) and the second reservoir tank (20).

For example, a pressure difference may be induced between the first reservoir tank 10 and the second reservoir tank 20 to supply the heat medium fluid to the first reservoir tank 20. When the first reservoir tank 10 is continuously pressurized in the state where the connection control valve 111 is closed for the heat medium circulation, the water level of the first reservoir tank 10 is reduced, so that the connection control valve 111 is opened 2 heat medium fluid can be supplied from the reservoir tank 20 to the first reservoir tank 10. At this time, by opening the first pressure reducing valve 131 to depressurize the first reservoir tank 10 and keeping it at a relatively low pressure state, the heat medium fluid stored in the second reservoir tank 20 flows into the first reservoir tank (10). After the supply of the heat medium fluid is completed, the connection control valve 111 is closed to again maintain the pressure of the first reservoir tank 10 higher than the pressure of the second reservoir tank 20, and the heat medium fluid can be circulated .

The mold part 30 may include at least one mold plate in which a flow path 31 through which the heat medium fluid flows is formed. The flow path 31 may be formed by passing through at least one of the mold plates constituting the mold part 30, respectively. The mold part 30 may have a cavity for molding the product between the pair of mold plates and may include a conduit connected to the cavity so that the melted material can be injected into the cavity . The mold part 30 may be formed in various sizes and shapes, and the shape of the cavity may be variously modified depending on the shape of the product. The flow path 31 can extend into the mold section 30 along a path adjacent to the cavity of the mold section 30. [

The heating unit 40 may be connected to one side of the main flow path 60. 2, the heating unit 40 includes at least one heater 42, a temperature controller 43 for controlling the temperature of the heater 42, a heat exchanger 43 for heat exchange at least once through the heater 42, And may include a flow path 31. The heat exchange flow path 31 is directly connected to the main flow path 60 so that the temperature of the heat medium fluid and the dryness of the steam can be increased while allowing the heat medium fluid of the main flow path 60 to pass therethrough. (The increase in temperature and quality is an increase in enthalpy.) The heater 42 may be formed so as to be heated to a desired temperature under the control of the temperature controller 43, including a hot wire. As shown in the figure, the heat exchange flow path 31 is composed of a serpentine-shaped conduit, and is repeatedly refracted around the heater 42 to increase the temperature of the heating medium fluid more efficiently, . ≪ / RTI >

In this manner, the heat medium fluid can be heated while passing through the heating section 40 while moving from the first reservoir tank 10 to the mold section 30. The heated heat medium fluid is injected into the flow path 31 in the mold section 30 to heat the mold section 30 with heat exchange and to raise the temperature of the mold section 30 and to control the pressure of the second reservoir tank 20 The pressure condition can be maintained to maintain a higher temperature continuously. In this way, the product can be molded while adjusting the temperature of the mold part 30. [ The specific operation process of the injection molding apparatus 1 will be described later in more detail.

1, a cooling water supply pipe 62 and a purge gas supply pipe 63 can be connected between the heating unit 40 and the mold unit 30, and the mold unit 30 and the second reservoir tank And a drain pipe 71 may be connected between the drain pipe 20 and the drain pipe 71. The cooling water supply pipe 62 and the purge gas supply pipe 63 are connected to the main flow path 60 between the heating part 40 and the mold part 30 to supply cooling water or purge gas to the inside of the flow path 31 of the mold part 30. [ And may be formed to selectively supply purge gas. The drain pipe 71 may be formed so as to be branched to one side of the pressure control pipe 70 to discharge the cooling water or the purge gas supplied to the channel 31 to the outside. The valves 621, 631 and 711 connected to the cooling water supply pipe 62, the purge gas supply pipe 63 and the drain pipe 71 are controlled to cool each other to supply the cooling water to cool the mold part 30, The operation of cleaning the inside of the unit 30 can be performed very easily.

By using the injection molding apparatus 1 of the present invention configured as described above, the temperature of the mold section 30 can be more controlled and maintained at a temperature suitable for molding, and a high quality product can be manufactured. Hereinafter, a control method of the injection molding apparatus and an operation process of the injection molding apparatus according to an embodiment of the present invention will be described in detail with reference to FIGS. 3 to 8. FIG.

For the sake of explanation, each sequence (S100 to S800) will be described with reference to the flowchart of Fig. 8, and a detailed description of each sequence will be given referring to the operation diagrams of the remaining Figs. 3 to 7 together. The description of each component of the injection molding apparatus shall be applied to the same description as the above description unless otherwise stated.

FIGS. 3 to 7 are views showing the operation of the injection molding apparatus of FIG. 1, and FIG. 8 is a flowchart illustrating a control method of the injection molding apparatus according to an embodiment of the present invention.

Referring to FIG. 8, a control method of an injection molding apparatus according to an embodiment of the present invention includes the steps of: guiding a pressure difference between a first reservoir tank connected to a front end of a flow path formed in a mold portion, (S200) of flowing a heating medium fluid from the first reservoir tank to the second reservoir tank via the flow path (S200); and adjusting or maintaining the pressure inside the flow path through which the heating medium fluid passes by adjusting the pressure of the second reservoir tank (S300, S400). That is, a process of heating the mold part by inducing a pressure difference between the first reservoir tank and the second reservoir tank and circulating the heat medium fluid, and controlling the pressure of the flow path in the mold part by using the second reservoir tank, It is possible to maintain the temperature at a temperature suitable for production of a product and mold a high quality product.

First, before starting the full-scale molding operation, the temperature of the heating portion (see 40 in FIG. 3) is raised and the water level of the first reservoir tank (see 10 in FIG. 3) and the second reservoir tank (S100) may be performed first. Since the heating medium fluid (refer to A in FIG. 3) must be heated enough to keep the mold section 30 at a proper molding temperature, the heating section 40 can be preheated close to this temperature or the temperature can be raised to the required temperature .

The water level of the first reservoir tank 10 and the second reservoir tank 20 flows into the second reservoir tank 20 through the supply flow path 21 or through the connection flow path 11, The fluid A can be supplied to the first reservoir tank 10 and adjusted appropriately. The first pressure reducing valve 131 may be formed at a position where the heat medium fluid A can be discharged to open the first pressure reducing valve 131 and to discharge a part of the heat medium fluid A. [ Further, a separate discharge valve (not shown) may be formed in the first reservoir tank 10 and the second reservoir tank 20 to discharge the thermal medium fluid A as necessary. In this way, the water level of the first reservoir tank 10 and the second reservoir tank 20 can be adjusted and prepared.

3, the first reservoir tank 10 is pressurized to induce a pressure difference between the first reservoir tank 10 and the second reservoir tank 20, and the first reservoir tank 10, The thermal medium fluid A flows from the first reservoir tank 10 to the second reservoir tank 20 via the flow path 31 to heat the metal mold 30 (S200). At this time, the first injection valve 51 of the pressurization unit 50 is adjusted to open the first injection pipe 51, and the compressed air B is supplied to the first reservoir tank 10 at the pneumatic pressure as described above, Can be increased. The connection passage 11 is closed to keep the first reservoir tank 10 and the second reservoir tank 20 disconnected and the conduit connected to the second reservoir tank 20 can open only the pressure control pipe 70 have.

That is, a pneumatic pressure may be applied to the first reservoir tank 10 to generate a pressure difference between the first reservoir tank 10 and the second reservoir tank 20. If necessary, it is also possible to provide air pressure to the first reservoir tank 10 as well as the second reservoir tank 20 to adjust the mutual pressures and to derive the pressure difference. In this manner, the pressure of at least one of the first reservoir tank 10 and the second reservoir tank 20 can be adjusted by providing the pneumatic pressure, and thus, the problems Can be effectively solved.

By inducing the pressure difference as described above, the heat medium fluid A can flow very smoothly along the main flow path 60. The heat medium fluid A passes through the heat exchanging flow path 31 of the heating section 40 while flowing along the main flow path 60 and is heated by the heater 42 around the heat exchanging flow path 31, As shown in Fig. The heat medium fluid A exchanges heat with the mold section 30 in the flow path 31 while passing through the flow path 31 to raise the temperature of the mold section 30. [

The heat medium fluid A may be recovered to the second reservoir tank 20 along the pressure control pipe 70 after passing through the mold part 30. [ That is, the pressure control pipe 70 may also serve to recover the heat medium fluid A as described above. Since the pressure regulating pipe 70 is directly connected to the flow path 31 of the mold part 30, not only the heat medium fluid A is recovered but also the pressure change of the second reservoir tank 20 is applied to the flow path 31 It can also play a role of direct propagation. A region where the heat medium fluid (A) flows and a region where air flows can coexist within the pressure control pipe (70).

When a pressure drop is detected from the pressure sensor, the pressure of the second reservoir tank 20 is adjusted as shown in Fig. 4, so that the pressure change is propagated through the pressure control pipe 70 and the heat medium fluid A flows The pressure inside the flow path 31 is changed or maintained (S300, S400). Since the second reservoir tank 20 is directly connected to the rear end of the flow path 31, the internal pressure of the second reservoir tank 20 can be increased to easily relieve the pressure drop that may occur at the rear end of the flow path 31. The pressure drop can be detected from the second sensor unit 22, but it is also possible to directly detect the pressure inside the flow path 31 by inserting a pressure sensor into the flow path 31 if necessary.

In particular, the pressure of the second reservoir tank 20 can be kept lower than the pressure of the first reservoir tank 10 during circulation of the heat medium fluid, as described above. The pressure difference between the first reservoir tank 10 and the second reservoir tank 20 is induced and the pressure inside the flow path 31 formed in the mold part 30 can be controlled so as not to be reduced to the atmospheric pressure or less. The heating medium fluid A is heated by the heating section 40 to be converted into a vapor state and flows inside the flow path 31 to perform heat exchange so that the saturated vapor pressure of the heating medium fluid A is raised to increase more heat medium fluid A It is possible to switch to the vapor state and maintain the temperature of the heat medium fluid A at a higher temperature. That is, it is possible to increase the pressure inside the flow path 31 so that the heat medium fluid A is not depressurized down to a certain saturated vapor pressure, and it is possible to keep the heat medium fluid A at a high temperature. Maintenance and modification of these pressure conditions can be made very easily using air pressure.

The second injection valve 52 is opened and the compressed air B is supplied to the second reservoir tank 20 by adjusting the second injection valve 521 as shown in FIG. (20). Since the pressure of the second reservoir tank 20 is directly transmitted to the flow path 31 through the pressure control pipe 70 as described above, the pressure of the flow path 31 can be increased together. Thereby, it is possible to change the pressure inside the flow path 31 to a required pressure or maintain it at an appropriate level. However, if the pressure is excessive, the heat medium fluid A may flow back to the first reservoir tank 10, so that the first sensor unit 12 and the second sensor unit 22 take into account the magnitude of the pressure measured by the first sensor unit 12 and the second sensor unit 22 When the pressure is excessive, the second pressure reducing valve 231 is opened and the air B 'in the second reservoir tank 20 is exhausted to set the pressure of the second reservoir tank 20 at an appropriate level, that is, It is desirable to adjust the level to a level lower than that of the tank 10.

In this way, the temperature of the mold part 30 can be maintained while adjusting the pressure inside the flow path 31, and the product can be molded at the optimum temperature. 5, the flow of the heat medium fluid A is stopped (S500), and the cooling water C is supplied to the flow path 31 to cool the mold portion 30 (S600). At this time, in order to stop the flow of the heat medium fluid A, the valves 601 and 602 of the main flow path 60 are adjusted to close the main flow path 60 and the valve 701 of the pressure control pipe 70 So that the pressure regulating pipe 70 can also be switched to the closed state.

On the other hand, the cooling water supply pipe 62 regulates and opens the valve 621 and the drain pipe 71 also regulates and opens the valve 711 so that the cooling water C flows through the cooling water supply pipe 62, And then discharged to the drain pipe 71. [0050] In this way, the cooling water C is supplied to the flow path 31 to cool the mold part 30. [ After product molding is completed, the temperature can be reduced to prevent deformation of the product and to keep the product in a finished state.

During the cooling of the mold part 30, the heating medium fluid A may be supplied to at least one of the reservoir tanks as shown in FIGS. 5 and 6 (S700). That is, the heat medium fluid A that evaporates during the molding process or remains in the pipe can be supplemented during the cooling operation of the mold section 30. [ The supply fluid passage 21 can be opened to supply the heat medium fluid A to the second reservoir tank 20 with priority and the connection control valve 111 and the first pressure reducing valve 131 The connection fluid passage 11 may be opened and the thermal medium fluid A may be redistributed from the second reservoir tank 20 to the first reservoir tank 10. [ If necessary, the pressure reducing valve of each reservoir tank can be opened to adjust the pressure inside the tank so that it does not increase excessively.

5, the heating medium fluid A is first supplied to the second reservoir tank 20 through the supply passage 21, the second pressure reducing valve 231 is opened to open the second reservoir tank 20, It is possible to adjust the pressure inside the valve body 20. 6, the second reservoir tank 20 is opened by opening the connection passage 11 and the first pressure reducing valve 131 and relatively lowering the pressure of the first reservoir tank 10 to induce a pressure difference, The heat medium fluid A supplied to the first reservoir tank 10 can be distributed to the first reservoir tank 10. Thus, the heat medium fluid A can be easily supplied to each reservoir tank while adjusting the pressure inside the reservoir tank.

7, the cooling water supply pipe 62 is closed to cut off the supply of the cooling water C and the purge gas supply pipe 63 is opened to the inside of the oil passage 31 The purge gas D can be supplied (S800). Impurities in the flow path 31 can be easily removed. As described above, even when the purge gas D is being supplied, the supply passage 21, the connection passage 11, and the like are opened and any one of the first reservoir tank 10 and the second reservoir tank 20 is filled with the heat medium fluid (A) can be performed in parallel. In this way, a high-quality product can be molded at an optimum temperature, and if necessary, the product can be additionally manufactured by switching the injection molding apparatus 1 to a prepared state again.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken in conjunction with the present invention. You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1: injection molding apparatus 10: first reservoir tank
11: connecting flow path 12: first sensor part
13: first pressure regulating tube 20: second reservoir tank
21: supply passage 22: second sensor section
23: second pressure regulating tube 30: mold part
31: flow path 40: heating section
41: heat exchange channel 42: heater
43: Temperature controller 50:
51: first injection tube 52: second injection tube
53: air compressor 60: main flow path
62: cooling water supply pipe 63: purge gas supply pipe
70: Pressure regulating tube 71: Drain tube
111: connection control valve 131: first pressure reducing valve
231: Second pressure reducing valve
211, 601, 602, 621, 631, 701, 711: valve
511: first injection valve 521: second injection valve
A: Heat medium fluid B: Compressed air
C: Cooling water D: Purge gas

Claims (15)

A mold section in which a flow path through which the heat medium fluid flows is formed;
A first reservoir tank disposed at a front end of the mold unit and connected to the flow path to supply the heat medium fluid to the flow path;
A heating unit disposed between the first reservoir tank and the mold unit and heating the heat medium fluid injected into the mold unit; And
And a second reservoir tank disposed at a rear end of the mold section and connected to the flow path to regulate a pressure of the flow path. The method according to claim 1,
Wherein the pressure of the second reservoir tank is kept lower than the pressure of the first reservoir tank while the heat medium fluid circulates. The method according to claim 1,
A pressurizing portion for injecting air into at least one of the first reservoir tank and the second reservoir tank to increase the pressure of at least one of the first reservoir tank and the second reservoir tank,
Further comprising a pressure reducing valve connected to each of the first reservoir tank and the second reservoir tank. The method of claim 3,
The pressurizing unit includes an air compressor,
A first injection pipe connected between the air compressor and the first reservoir tank,
A second injection pipe connected between the air compressor and the second reservoir tank,
And an injection valve for opening and closing each of the first injection pipe and the second injection pipe. The method according to claim 1,
A connection channel connected between the first reservoir tank and the second reservoir tank,
The connection passage is opened to allow the first reservoir tank and the second reservoir tank to communicate with each other,
And a connection control valve closing the connection passage to disconnect the first reservoir tank and the second reservoir tank from each other. 6. The method of claim 5,
And a supply passage connected to the second reservoir tank for supplying the heat medium fluid to the second reservoir tank. The method according to claim 1,
Further comprising a sensor portion formed in the first reservoir tank and the second reservoir tank, the sensor portion including a water level sensor and a pressure sensor. The method according to claim 1,
The heating unit includes at least one heater,
A temperature controller for controlling the temperature of the heater, and
And a heat exchange channel which is bent at least once with the heater interposed therebetween and into which the heat medium fluid flows. The method according to claim 1,
A cooling water supply pipe connected between the heating unit and the mold unit for supplying cooling water to the flow path,
A purge gas supply pipe connected between the heating unit and the mold unit to supply the purge gas to the flow channel,
And a drain pipe connected between the mold part and the second reservoir tank. A pressure difference is induced between a first reservoir tank connected to the front end of the flow path formed in the mold section and a second reservoir tank connected to the rear end and flows from the first reservoir tank to the second reservoir tank through the flow path ; And
And controlling the pressure of the second reservoir tank to change or maintain the pressure in the flow passage through which the heat medium fluid passes. 11. The method of claim 10,
Wherein the pressure of the second reservoir tank is kept lower than the pressure of the first reservoir tank while the heat medium fluid circulates. 11. The method of claim 10,
Providing a pneumatic pressure to at least one of the first reservoir tank and the second reservoir tank,
Wherein a pressure difference is generated between the first reservoir tank and the second reservoir tank or a pressure of at least one of the first reservoir tank and the second reservoir tank is adjusted. 11. The method of claim 10,
The first reservoir tank and the second reservoir tank are directly connected to each other,
Wherein the pressure of the first reservoir tank and the pressure of the second reservoir tank are mutually adjusted or the heat medium fluid accommodated in the second reservoir tank is supplied to the first reservoir tank. 11. The method of claim 10,
Wherein the heat medium fluid is heated between the first reservoir tank and the mold section,
And heat exchange is performed with the mold part while passing through the flow path inside the mold part. 11. The method of claim 10,
Stopping the flow of the heat medium fluid,
Supplying cooling water to the flow path to cool the mold part, and
And supplying purge gas to the flow path to clean the flow path.

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