JP2010083122A - High-speed injection molding system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-speed injection molding system in which the high temperature of a heating member does not affect a succeeding cooling process, heating power of the heating member can be drastically improved and the injection molding speed can be accelerated. <P>SOLUTION: Before a die is heated by the movable heating member and a liquid raw material is injected into a cavity of the die, the heating member is moved and brought into contact with the die to heat the die to a working temperature. When the temperature of the die reaches the working temperature, the heating member is moved and separated from the die. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to injection molding, and more particularly to a high-speed injection molding system that can improve the heating power of a mold and increase injection molding efficiency.

  In high-speed injection molding systems, the mold must first be heated to a relatively high working temperature to ensure that the raw material liquid injected into the cavity maintains good fluidity and can be quickly filled into the cavity. is there. Subsequently, the mold must be quickly cooled to the mold opening temperature, the mold must be opened and the injection molded member removed.

  As shown in FIG. 1, in a conventional high-speed injection molding system, a mold 1 includes a plurality of passages 2. These passages 2 can connect the head and tail in series, and can be connected to the water inlet / outlet pipe. The passages 2 can also be connected in parallel to the inlet / outlet water lines. Before closing the mold 1, high-temperature steam is injected into the passage 2, whereby the molding mold 1 is heated, and then the mold is closed to perform molding. After the molding is completed, cooling water is introduced into the passage 2 to accelerate the cooling rate so that the molding die 1 can be opened as quickly as possible. The passage 2 can be used for passage of high-temperature steam or cooling water, and is used simultaneously for heating and cooling the mold 1.

  However, the heat exchange rate between the high temperature fluid and the mold 1 cannot be efficiently improved due to the restriction of the passage 2. If the flow rate of the high-temperature fluid is simply increased, the high-temperature fluid can only pass through the passage 2 quickly. To improve the heat exchange rate, it is necessary to increase the contact area between the high-temperature fluid and the mold 2. As a method for increasing the contact area, there are a method for increasing the number of passages 2 and a method for increasing the diameter of the passages 2. Both of the method for increasing the number of the passages 2 and the method for increasing the diameter of the passages 2 are available. The hollow structure in the mold 1 becomes large, leading to insufficient stress in the mold 1.

  The method of solving the problem of not being able to improve the heating power is to heat the mold using an electric heating member. A common method is to embed an electric heating member such as a heating rod in the mold. The heating efficiency can be easily improved by increasing the input power. However, at the same time as increasing the input power, the temperature of the electrothermal member also increases. In the cooling process of the mold, the residual heat amount of the electric heating member adversely affects the cooling efficiency, and the cooling time becomes long, so that the injection molding efficiency cannot be improved truly. Although the induction heating coil that does not contact the mold does not have a problem that the residual heat amount affects the cooling efficiency, the induction heating coil can only locally heat the mold surface, and the heating efficiency is excellent in a large mold. There is no problem. For this reason, how to improve the heating efficiency and avoid the problem that the residual heat quantity affects the cooling efficiency is a technical problem.

  An object of the present invention is to provide a high-speed injection molding system that can significantly increase the heating power of the heating member without accelerating the subsequent cooling process, and can accelerate the injection molding speed. It is to provide.

  To achieve the above objective, the high speed injection molding system of the present invention is used in the manufacture of an injection molded member, which includes a mold, a cooling fluid source, and a heating member, said mold having a hollow cavity and A plurality of passages, wherein the cavity is used for injecting the raw material liquid therein, and the cooling fluid supply source provides a cooling fluid to each passage, and the mold is cooled by the cooling fluid to form a liquid resin. Used for accelerating the cooling and solidification process, the heating member is movably installed and can be selectively brought into contact with the mold to heat it or be separated from the mold, When it is no longer necessary to heat the mold with the heating member, the heating member can be detached from the mold so that the residual heat does not continue to heat the mold.

  Since the heating member can be detached from the mold, the residual heat does not continue to heat the mold. For this reason, the heating member can be heated with higher heating power, and there is no need to consider the problem that the high temperature of the heating member affects the cooling efficiency. As a result, the present invention can shorten the heating time, maintain good cooling efficiency, and improve injection molding efficiency.

[Example 1]
FIG. 2 shows a high-speed injection molding system according to the first embodiment of the present invention. This high-speed injection molding system is used to manufacture injection molded members, and includes a mold 10, a mold opening / closing device 20, a molding machine 30, a temperature control device 40, a heating member 50, and a moving device 60.

  As shown in FIG. 2, the mold 10 includes a male mold 11 and a female mold 12, and the male mold 11 and the female mold 12 each have a protruding or recessed structure corresponding to each other, and the male mold 11 and the female mold 12 are mutually connected. Then, a hollow cavity 13 is formed between the male mold 11 and the female mold 12, and is used to inject the raw material liquid therein. After the raw material liquid to be filled in the cavity 13 is cooled and solidified, an injection molded member whose form matches the cavity 13 is formed. The male mold 11 includes an injection path 111 communicating with the cavity 13, and the molding machine 20 is connected to the injection path 111. A material feed screw (not shown) of the molding machine 30 is rotated and supplied simultaneously, and the raw material liquid is pushed to pass through the injection path 111 and injected into the cavity 13. The mold 10 further includes a plurality of passages 14 and insertion holes 15. Among them, the passage 14 and the insertion hole 15 can be provided in any one of the male mold 11 and the female mold 12, or can be installed in the male mold 11 and the female mold 12 at the same time. In this embodiment, the passages 14 and the insertion holes 15 are all installed in the female mold 12, and the insertion holes 15 are alternately arranged with the passages 14, and each insertion hole 15 has at least one open end.

  As shown in FIG. 2, the mold opening / closing device 20 is used for driving the male mold 11 and the female mold 12 to close each other and closing the molds or separating them from each other to perform mold opening. The mold opening / closing device 20 can be a hydraulic device, a multi-link actuator, or a linear feed screw assembly. In the present embodiment, the mold opening / closing device 20 is a hydraulic device and includes a support 21 and at least one hydraulic cylinder 22. Among them, the support body 21 and the hydraulic cylinder 22 are installed on the machine base 24, and the drive rod 23 of the hydraulic cylinder 22 is penetrated into the support body 21 and connected to the female mold 12 of the mold 10. It is installed on the machine base 24 so as to be movable. The male mold 11 is fixedly installed on the machine base 24, and the drive rod 23 of the hydraulic cylinder 22 moves the female mold 12 linearly to close the male mold 11 to close the mold 10. Alternatively, the female mold 12 is moved linearly to be detached from the male mold 11 and the mold 10 is opened.

  As shown in FIG. 2, the temperature control device 40 is used to control the temperature of the mold 10, and provides a high-temperature fluid into the passage 14 before the raw material liquid is injected into the mold 10. 10 is heated. After completion of molding, the temperature control device 40 provides cooling fluid into the passage 14 to cool the mold 10. The temperature control device 40 includes a high-temperature fluid supply source 41, a cooling fluid supply source 42, and a drainage device 43. The temperature control device 40 is connected to one end of the passage 14 and collects fluid from the other end of the passage 14. The high temperature fluid supply source 41 is used for providing a high temperature fluid such as high temperature steam. The cooling fluid supply source is used to provide a cooling fluid such as cooling water. The drainage device 43 is used to generate a high-speed air flow in the passage 14 by suction or pumping and to discharge the high-temperature fluid or cooling fluid remaining in the passage 14.

  As shown in FIGS. 2, 3, and 4, the heating member 50 is installed so as to be movable, and can be selectively brought into contact with or separated from the mold 10. The heating member 50 includes a plurality of heating rods 51 and connecting seat portions 52, of which one end of each heating rod 51 is fixed to the connecting seat portion 52, arranged in parallel with each other of the heating rods 51, and the mold 10. Corresponds to the insertion hole 15. Each electric heating rod 51 obtains a working current by a conducting wire, and generates a heating working current in each electric heating rod 51. The moving device 60 can be a mechanical arm or hydraulic cylinder, a linear feed screw assembly, a pinion and rack combination. The connecting seat portion 52 of the heating member 50 is connected to the moving device 60, and the moving device 60 moves the connecting seat portion 52 to move the electric heating rod 41 along the insertion path. The insertion path is an axis parallel to the insertion hole 15. When the female mold 12 is moved to the mold opening position, the insertion path overlaps with the axis of each insertion hole 15. For this reason, when the electric heating rod 15 is moved to the female die 12 along the installation path, each electric heating rod 51 is inserted into the corresponding insertion hole 15 to come into contact with the female die 12, and against the female die 12. Can be heated.

  Example 1 is used during the injection molding operation, and the process is as follows.

  As shown in FIG. 2, when the injection molding operation is started or after the previous injection molding operation is completed, the mold 10 is in an opened state, and the injection molding member for which the previous injection molding operation has been completed is It can be taken out at this time. At the same time, the hot fluid supply source 41 starts providing hot fluid and starts heating the mold 10 through the passage 14.

  As shown in FIGS. 4 and 5, the moving device 60 moves the heating member 50 and inserts the electric heating rod 51 into the insertion hole 15 to contact the female die 12. The electric heating rod 51 is energized at the same time and starts heating the female die 12. The electric heating rod 51 can introduce a large current up to the upper limit of its operation, and can accelerate the heating of the mold 10 to the working temperature. When the power of the heating rod 51 is sufficient to heat the mold 10 to the working temperature within a short time, the temperature control device 40 does not need to provide the hot fluid in the passage 14. In other words, the mold 10 need only be heated by an electric heating rod, and need not be further heated by a high-temperature fluid.

  As shown in FIG. 6, when the temperature of the female die 12 reaches the working temperature, the high temperature fluid supply source 41 stops the supply of the high temperature fluid, and at the same time, the energization of the working current to the electric heating rod 51 is also stopped. Stop heating to 20. At the same time, the heating member 50 is also moved by the moving device to leave the female die 12, the electric heating rod 51 leaves the insertion hole 15, and does not contact the mold, and the high temperature of the electric heating rod 51 itself continues to heat the female die 12. In this case, it is avoided that the temperature of the female mold 12 is too high and the time for cooling and solidifying the subsequent raw material liquid is extended. After the electric heating rod 51 leaves the insertion hole 15, the mold opening / closing device 30 drives the female mold 12 to close the male mold 11 and the mold closing operation is completed. Subsequently, the molding machine 20 injects the raw material liquid into the mold 10 and fills the cavity 13 with the raw material liquid.

  After the injection is completed, that is, after the raw material liquid is filled in the cavity 13, the high-temperature fluid remaining in the passage 14 is first discharged by the drainage device 43, and then the cooling fluid supply source 42 provides the cooling fluid. And the mold 10 is cooled. The molding machine 20 maintains the pressure of the raw material liquid in the cavity 13, and the cooling fluid supply source 42 continues to cool the mold 10. When the surface temperature of the cavity 13 reaches the mold opening temperature, the cooling fluid supply source 42 stops supplying the cooling fluid. At this time, since the heating rod 51 of the heating member 50 has already left the mold 10, the high-temperature heating rod 51 does not continue to exchange heat with the female die 12, thereby cooling the heating member 50. The influence on the process can be avoided and the time required for cooling can be greatly shortened.

  Finally, the mold opening device 30 drives the female mold 12 to separate it from the male mold 11, and the surface of the cavity 11 is exposed as shown in FIG. At the same time, the high-temperature fluid supply source 41 starts providing the high-temperature fluid, introduces it into the passage 14, starts heating the mold 10 again, and prepares for the next injection molding operation. At the same time, the mold 10 heated moderately is advantageous for releasing the injection-molded member.

  The spirit of the present invention is that the heating efficiency for the mold 10 can be easily improved through a method in which the heating member 50 receives a large current, and the time required for heating the mold 10 can be shortened. After the heating is completed, it is detached from the mold 10 so that heat exchange is not performed, and the high temperature heating member 50 is prevented from affecting the cooling and solidification process of the raw material liquid. As a result, the present invention shortens the heating time, maintains a good cooling efficiency, and does not extend the cooling time.

[Example 2]
FIG. 8 shows a high-speed injection molding system according to the second embodiment of the present invention. This high-speed injection molding system is used for manufacturing an injection-molded member, and a temperature control device 40 further includes a cooling plate 44 that is movably installed on the machine base 24 and is driven by the transmission device 25. The cooling plate 44 is disposed outside the female mold 12, that is, disposed between the female mold 12 and the support 21 of the mold opening / closing device 20. The transmission 25 is used to move the cooling plate 44, the cooling plate 44 is brought into contact with the female die 12 of the mold 10, the cooling plate 24 absorbs heat from the female die 12, and the temperature of the entire mold 10 is opened. Accelerate the rate of down to temperature. The cooling plate 44 may be a metal plate including a thermoelectric generator or a metal plate provided with a cooling line. Since the cooling plate 44 is not a part of the mold 10, the stress intensity does not need to match the requirements of the molding conditions. Since it is not necessary to consider the stress requirement of the cooling plate 44, the cooling structure in the cooling plate 44 can easily reach the requirement of the maximum cooling power, and the cooling process of the mold 44 can be accelerated.

  In addition, after the mold closing operation is completed, the cooling plate 44 is brought into contact with the female mold 12, and the temperature of the outer surface of the female mold 12 is started to be lowered, so that the cooling operation for the mold 10 can be performed early. Since the cooling plate 44 starts to cool down from the surface of the female die 12, the surface temperature of the cavity 13 is not changed immediately, so that the liquid resin flows sufficiently while maintaining the high temperature and fills the cavity 13. Can do.

[Example 3]
9 and 10 show a high-speed injection molding system according to Embodiment 3 of the present invention. The heating member 50 includes a plurality of electric heating bars 51 and a heat conducting plate 53. The heat conducting plate 53 is made of a material having a high thermal conductivity coefficient, and the electric heating rod 51 is embedded in the heat conducting plate 53. The heat conducting plate 53 is connected to the moving device 60, and the moving device 60 moves and moves the heat conducting plate 53 to contact the outer surface of the female die 12. After the electric heating rod 51 receives electric power and generates heat, the heat conducting plate 53 can heat the female die 12.

As shown in FIGS. 11 and 12, in order to reduce the thermal resistance of the contact between the heat conducting plate 53 and the mold 10, it is necessary to increase the contact area between the mold 10 and the heat conducting plate 53. For this reason, an uneven structure combined with each other is formed on the outer surface of the female die 12 and the outer surface of the heat conducting plate 53, thereby increasing the contact area between the mold 10 and the heat conducting plate 53. Among them, a plurality of parallel groove portions 121 are provided on the outer surface of the female die 12, and the passage 14 passes through the protruding area between the adjacent groove portions 121. A plurality of parallel rib portions 531 are formed on the surface of the heat conducting plate 53, the electric heating rod 51 is embedded in the rib portions 531, and the cross-sectional shape of each rib portion 531 matches the cross-sectional shape of the groove portion 121, The contact area between the mold 10 and the heat conducting plate 53 is increased by coupling the rib portion 531 to the groove portion 121.
[Example 4]

  FIG. 13 shows a high-speed injection molding system according to Embodiment 4 of the present invention. The fourth embodiment discloses another form of the heating member 50, which includes an induction heating coil 54, a magnetic conducting plate 55, and a heat conducting plate 53, and the magnetic conducting plate 55 is made of a metal having a relatively excellent magnetic permeability. And the induction heating coil 54 is coupled to the outer surface of the magnetic plate 55 via at least one insulating member 541, whereby the induction heating coil 54 is connected to the magnetic plate 55. Close but not touching. When a high-frequency alternating current is conducted to the induction heating coil 54, a magnetic field change is generated with respect to the magnetic guide plate 55, and an outer surface of the magnetic guide plate 55 is induced by the magnetic field change to generate an eddy current. The current causes the magnetic conduction plate 55 to generate heat, and the amount of heat is conducted to the heat conduction plate 53. The heat conducting plate 53 is connected to the moving device 60, and the moving device 60 moves and moves the heat conducting plate 53 to contact the female die 12 to heat the female die 12.

  As shown in FIG. 14, in the fourth embodiment, the magnetic guide plate 55 is not an essential member, and the induction heating coil 54 is coupled to the outer surface of the heat conductive plate 53 via the insulating member 531, whereby the induction heating coil 54 is Although it is approaching the heat conducting plate 53, it is not in contact. When a high-frequency alternating current is conducted to the induction heating coil 54, a magnetic field change occurs in the heat conducting plate 53, the outer surface of the heat conducting plate 53 is induced by the magnetic field change to generate an eddy current, and the eddy current becomes a heat conducting plate. 53 can generate heat and the female die 12 can be heated.

It is sectional drawing of the injection molding system in a prior art. It is sectional drawing of Example 1 of this invention. In Example 1, it is a three-dimensional view which shows the state which the heating member detach | leaved from the female type | mold. In Example 1, it is a three-dimensional view which shows the state which the heating member contacted the female type | mold. It is sectional drawing 1 which shows the process of the injection molding of Example 1 of this invention. It is sectional drawing 2 which shows the process of the injection molding of Example 1 of this invention. It is sectional drawing 3 which shows the process of the injection molding of Example 1 of this invention. It is sectional drawing of Example 2 of this invention. It is a three-dimensional view which shows the state which the heating member contacted the female type | mold in Example 3 of this invention. It is a three-dimensional view showing a state where the heating member is detached from the female mold in Example 3 of the present invention. It is sectional drawing which shows the state which the heating member of another form of Example 3 of this invention removed from the female type | mold. It is sectional drawing which shows the state which the heating member of another form of Example 3 of this invention contacted the female type | mold. It is sectional drawing which shows the state from which the heating member detach | leaved from the female type | mold in Example 4 of this invention. It is sectional drawing which shows the state from which the heating member detach | leaved from the female type | mold in Example 4 of this invention.

Explanation of symbols

1 ····························· 10 ········································································ ... Groove 13 ... Cavity 14 ... Passage 15 ... Insertion hole 20 ... Mold opening / closing device 21 ... Support 22 ... Hydraulic cylinder 23 ... drive rod 24 ... machine base 25 ... transmission device 30 ... molding machine 40 ... temperature control device 41 ... high temperature Fluid supply source 42 ... Cooling fluid supply source 43 ... Drainage device 44 ... Cooling plate 50 ... Heating member 51 ... Electric heating rod 52 ... ··· Connection seat 53 ··· Heat conducting plate 531 ··· Rib portion 54 ··· Induction heating coil 541 · · · Insulating member 55 · · · Magnetic conducting plate 60 ···・ Moving device

Claims (20)

A high-speed injection molding system used for production of an injection molded member,
A mold having a hollow cavity and a plurality of passages for injecting the raw material liquid;
A cooling fluid supply providing cooling fluid for cooling the mold in each of the passages;
It includes a heating member that is movably installed and selectively contacts the mold for heating or is separated from the mold.
High speed injection molding system.   The high-speed injection molding system according to claim 1, further comprising a molding machine that pushes and moves the raw material liquid into the cavity.   The high-speed injection molding system according to claim 2, wherein the male mold further includes an injection path communicated with the cavity, and the molding machine is connected to the injection path.   The high-speed injection molding system according to claim 1, further comprising a mold opening / closing device used to operate the mold in a mold open or mold closed state.   The high-speed injection molding system according to claim 1, wherein the heating member includes a plurality of electric heating rods.   The mold according to claim 1, further comprising a plurality of insertion holes, each insertion hole having at least one open end, and being used for inserting each electric heating rod into a corresponding insertion hole. 5. A high-speed injection molding system according to 5.   The high-speed injection molding system according to claim 6, wherein the insertion holes are alternately arranged with the passages.   The high-speed injection molding system according to claim 5, wherein the heating member further includes a connecting seat portion, and one end of each electric heating rod is fixed to the connecting seat portion.   The heating member further includes a heat conducting plate, is selectively brought into contact with the mold or separated from the mold, and the electric heating rod is embedded in the heat conducting plate. The high-speed injection molding system according to claim 5.   The high-speed injection according to claim 9, wherein the mold and the heat conducting plate have a concavo-convex structure that is combined with each other, and are used to increase a contact area between the mold and the heat conducting plate. Molding system.   The mold includes a plurality of parallel groove portions, the heat conducting plate includes a plurality of parallel rib portions, and a cross-sectional shape of each of the rib portions matches a cross-sectional shape of each of the groove portions. The high-speed injection molding system according to 10.   The high-speed injection molding system according to claim 11, wherein each electric heating rod is embedded in each rib portion.   The heating member is selectively brought into contact with or separated from the mold, a heat conducting plate separated from the mold, a magnetic conducting plate coupled to the heat conducting plate, and an eddy current induced by the magnetic conducting plate. The high-speed injection molding system according to claim 1, further comprising an induction heating coil that generates   The high-speed injection molding system according to claim 13, wherein the induction heating coil is coupled to the magnetic guide plate through at least one insulating member.   The heating member includes a heat conducting plate that is selectively brought into contact with or separated from the mold and an induction heating coil that induces the heat conducting plate to generate an eddy current. The high-speed injection molding system according to claim 1.   The high-speed injection molding system according to claim 15, wherein the induction heating coil is coupled to the heat conducting plate via at least one insulating member.   The high-speed injection molding system according to claim 1, further comprising a high-temperature fluid supply source that provides a high-temperature fluid in each of the passages for heating the mold.   18. The high-speed injection molding according to claim 17, further comprising a drainage device used for generating a high-speed air flow in each of the passages and discharging a high-temperature fluid or a cooling fluid remaining in each of the passages. system.   The high-speed injection molding system according to claim 1, further comprising a cooling plate that is movably installed and is used to contact and cool the mold.   The high-speed injection molding system according to claim 1, further comprising a moving device used for moving the heating member.

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