JP3348807B2 - Molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding apparatus for polymer materials and the like, and more particularly to a molding apparatus for molding high-precision and high-quality parts.

[0002]

2. Description of the Related Art Conventionally, an injection molding apparatus has been developed as a high-productivity processing apparatus. Is being undertaken.

[0003] For example, Japanese Patent Application Laid-Open No. 61-44616 discloses that the fluidity of a resin is increased by induction heating a mold surface.
Methods for improving the accuracy and quality of thin molded products have been proposed. In Japanese Patent Application Laid-Open No. 58-134722, a cavity is formed by a horn for ultrasonic vibration, and a resin temperature gradient and a temperature non-uniformity are reduced in a process of cooling the resin in the cavity. Orientation, crystallinity, density,
There has been proposed a high-precision molding method in which unevenness in physical properties such as a shrinkage ratio is greatly reduced, and no warping or sinking occurs.

[0004]

However, the above-mentioned conventional molding method has the following problems.

In other words, according to the method proposed in Japanese Patent Application Laid-Open No. 61-44616, the surface of a mold is heated before injection.
The main molding process in which the effect of heating appears is the resin injection process, and the effect in the cooling process of the resin, which affects the accuracy and quality of the molded product, can hardly be expected. In addition, in order to perform induction heating, a high-frequency current is supplied to the mold, so that it is necessary to insulate the mold from the molding machine. Therefore, the molding machine has become complicated, or a safety device has been required in consideration of harm to the human body.

In the method proposed in Japanese Patent Application Laid-Open No. 58-134722, application of ultrasonic vibration is started simultaneously with emission.
This is a method of supplying thermal energy to the molding material by applying the voltage even during the cooling process of the resin. However, non-uniform physical properties such as orientation, crystallinity, density, and shrinkage due to temperature gradient and temperature non-uniformity mainly occur during the cooling process of the molding material. It can be said that it is not the target. Furthermore, since the ultrasonic vibration is converted into thermal energy at the interface between the molten layer and the solidified layer of the molding material, the effect as thermal energy is not very large when the molding material is still molten as in the injection process. Can't expect.

The present invention provides a molding apparatus which solves the above-mentioned problems, improves the fluidity of the molding material during injection, and reduces the non-uniformity of physical properties in the process of cooling the molding material. The purpose is.

[0008]

The present invention SUMMARY OF] includes a mold having a solid Jogawa mold and a movable side mold, and heating means for rapid heating of the surface of the portion forming the mold cavity, the Ultrasonic vibrating means for vibrating the whole or a part of the mold by ultrasonic waves, and heating time of the heating means to measure the surface temperature of the mold and set the mold surface to a desired temperature. and heating control means for controlling, before SL comprises a vibration control means for controlling the excitation timing and vibration time of the ultrasonic vibrating means, said pressurizing
The vibration control means sets the injection start point of the molding machine to the time measurement start point.
Measure the time and fill the cavity with the molding material
The ultrasonic vibration is started so that vibration is started immediately after completion.
It is characterized by controlling the means .

[0009]

According to the present invention, first, before the injection of the molding material, when the fixed side mold and the movable side mold of the mold maintained at a constant temperature by the temperature controller or the like are open, the heating means is used as the heating means. The surface of the mold is rapidly heated by moving the halogen lamp unit between the movable mold and the fixed mold and turning on the halogen lamp. By the rapid heating by the halogen lamp, only the mold surface is heated to a certain temperature or more controlled by the temperature controller, and when the mold surface temperature reaches a desired temperature, the halogen lamp is turned off and the halogen lamp unit is turned on. The mold is moved from between the fixed mold and the movable mold to close the mold. Immediately thereafter, as in normal injection molding, by injecting the molding material into the cavity,
The molding material is filled into the cavity while maintaining the high fluidity of the molding material.

Next, the molding material filled in the cavity is gradually cooled in a cooling process. In this cooling process, by applying ultrasonic vibration to the mold for a desired time, heat energy is generated at the interface between the solidified layer of the molding material and the molten layer, and the temperature gradient of the molding material, the temperature gradient, and the like. Uniformity can be reduced.

By doing so, it is possible to improve the fluidity of the molding material during the injection process and the temperature uniformity of the molding material during the cooling process, so that the orientation, crystallinity, density and shrinkage of the molded product can be improved. Greatly reduce the physical non-uniformity of
It is possible to realize a high quality molded product without warpage or sink.

[0012]

FIG. 1 is a perspective view showing an essential structure of a molding apparatus according to an embodiment of the present invention. In FIG. 1, reference numeral 11 denotes a fixed mold, 12 denotes a sprue serving as a passage of a molding material injected from a nozzle (not shown), 13 denotes a movable mold, and 14 denotes a movable mold.
An arrow indicating the opening / closing direction of 13, 15 is a cavity forming a molded product shape, 16 is a halogen lamp, 17 is at least one or more so as to face each of the fixed mold 11 and the movable mold 13. A halogen lamp unit with a halogen lamp 16 mounted thereon, 18 is a halogen lamp unit control device for controlling movement of the halogen lamp unit 17 and lighting of the halogen lamp 16, 19 is a moving arm for moving the halogen lamp unit 17, and 20 is a moving arm. An arrow indicating the moving direction of 19, 21 is an ultrasonic oscillator, 22 is a horn for transmitting the vibration of the ultrasonic oscillator 21 to the fixed mold 11, and 23 is an ultrasonic oscillator control for controlling the ultrasonic oscillator 21. The device, 24a is a temperature sensor for measuring the surface temperature of the fixed mold 11, and 24b is the movable mold 13.
The temperature sensor 25 for measuring the surface temperature of the mold receives the mold surface temperature signal 31 (FIG. 2) from the temperature sensors 24a and 24b, and controls the surface temperatures of the fixed mold 11 and the movable mold 13, respectively. A temperature controller, 26 is a vibration control signal line for transmitting an injection start signal 35 (FIG. 2) from the control panel 29 of the molding machine 30 shown in FIG. 2 to the ultrasonic vibrator controller 23, and 27 is a control of the molding machine 30. Mold opening / closing signal 33 from panel 29 to halogen lamp unit controller 18 (FIG. 2)
Is a heating device including the halogen lamp unit 17, the halogen lamp unit controller 18, the moving arm 19, and the temperature controller 25.

FIG. 2 is a block diagram of a control system in the molding apparatus of FIG. 2, reference numeral 29 denotes a control panel provided in the molding machine 30, 31 denotes a mold surface temperature signal transmitted from the temperature sensors 24a and 24b provided in the fixed and movable dies 11 and 13 to the temperature controller 25, 32 Is a halogen lamp extinguishing signal sent from the temperature controller 25 to the control panel 29 of the molding machine 30,
33 is a mold opening / closing signal sent from the control panel 29 to the moving arm 19 via the moving control signal line 27, and 34 is the temperature controller 25.
A moving signal transmitted from the control panel 29 to the moving arm 19, an injection start signal 35 transmitted from the control panel 29 to the ultrasonic vibrator control device 23 via a vibration control signal line 26, and 36 and 37 represent the ultrasonic vibration These are a vibration application timing signal and a vibration application time signal sent from the child control device 23 to the ultrasonic transducer 21.

FIG. 3 is a process diagram for explaining a molding process according to one embodiment of the present invention. Reference numeral 38 denotes an example of a cross-sectional shape of a molded product. A molding material is injected into a cavity 15 through a sprue 12 from a nozzle (not shown). Is done.

A process until a molded article is completed by the molding apparatus of the present invention will be described below with reference to FIGS. Hereinafter, (A) to (I) show the states of (A) to (I) in FIG.

(A) First, the fixed mold 11 and the movable mold 13
The molds 11 and 13 are opened while the temperature is maintained at a certain temperature by the temperature controller 25 or the like. At this time, the halogen lamp 16 of the halogen lamp unit 17 is turned off, and the ultrasonic vibrator 21 does not vibrate.

(B) When the mold opening / closing signal 33 is sent from the control panel 29 of the molding machine 30 to the halogen lamp unit controller 18, the moving arm 19 operates, and the halogen lamp unit 17 moves with the fixed mold 11. It moves between the side molds 13. At this time, as in (A), the halogen lamp 16 of the halogen lamp unit 17 is turned off, and the ultrasonic vibrator 21 does not vibrate.

(C) The moving arm 19 stops at a predetermined position,
The halogen lamp 16 is turned on by the halogen lamp unit controller 18, and the heating of the surfaces of the fixed mold 11 and the movable mold 13 is started. At this time, the fixed mold 11 and the movable mold
The surface temperatures of the fixed mold 11 and the movable mold 13 are measured by the temperature sensors 24a and 24b attached to the mold 13, respectively, and a mold surface temperature signal 31 is sent to the temperature controller 25. The temperature controller 25 controls the lighting time of the halogen lamp 16 until the surface temperatures of the fixed mold 11 and the movable mold 13 reach a desired temperature at which good fluidity of the molding material is obtained.

(D) When the surface temperatures of the fixed mold 11 and the movable mold 13 reach desired temperatures, the halogen lamp 16 is turned off by the temperature controller 25 and the halogen lamp is turned off on the control panel 29 of the molding machine 30. Signal 32 is sent.

(E) From the temperature controller 25 to the control panel 29 of the molding machine 30
Almost at the same time as the halogen lamp turn-off signal 32 is sent to the moving arm 19, the moving signal 34 is sent from the temperature controller 25 to the moving arm 19, and the mold opening / closing signal 33 is sent to the moving arm 19 from the control panel 29. As a result, the halogen lamp unit 17 moves from between the fixed mold 11 and the movable mold 13, and mold clamping starts even when the mold is clamped without interference between the movable mold 13 and the halogen lamp unit 17. In order to minimize the change in the surface temperature of the fixed mold 11 and the movable mold 13 heated by the halogen lamp unit 17, the movement of the halogen lamp unit 17 and the mold clamping should be performed in parallel. desirable.

(F) The molding material is injected into the cavity 15 upon completion of the mold clamping. Due to the rapid heating by the halogen lamp unit 17, the surface temperatures of the fixed mold 11 and the movable mold 13 are higher than the temperature of the mold body.
With the molding material maintaining good fluidity, the cavity 15
Is filled. Up to this point, the ultrasonic transducer 21 has not vibrated.

(G) Cooling of the molding material is started immediately after the molding material is filled in the cavity 15. The cooling start timing is measured by the injection start signal 35 sent from the control panel 29 of the molding machine 30 in the ultrasonic transducer control device 23, and the desired vibration application timing of the ultrasonic transducer 21 is determined. Further, the desired vibration application time of the ultrasonic transducer 21 is calculated and determined in advance by experiments or the like. The vibration application timing signal 36 and the vibration application time signal of the ultrasonic transducer 21 thus obtained
By vibrating the ultrasonic vibrator 21 based on 37, the vibration energy is reduced at the interface between the solidified layer of the molding material solidified due to the high cooling rate and the molten layer in the molten state due to the low cooling rate. It can be converted into heat energy and the temperature of the solidified layer can be raised again. This makes it possible to improve the temperature uniformity of the molding material during the cooling process, and significantly reduces the unevenness in physical properties such as the orientation, crystallinity, density, and shrinkage of the molded product 38, and reduces the warpage, High quality molded products without sinking can be realized.

(H) Next, the fixed mold 11 and the movable mold 13 are opened.

(G) When the fixed mold 11 and the movable mold 13 are opened, the molded product 38 is taken out.

By the above-described molding process, the non-uniformity of physical properties such as orientation, crystallinity, density, shrinkage, etc. is greatly reduced, and a high-quality molded article without warpage or sink can be realized.

[0026]

As described above, the molding apparatus of the present invention provides good fluidity by rapidly heating the surface temperatures of the fixed mold and the movable mold by the halogen lamp during the injection of the molding material. The molding material is filled into the cavity while being maintained, and in the process of cooling the molding material, ultrasonic vibration is applied to the mold at a desired time and for a desired time, thereby forming a solidified layer and a molten layer of the molding material. By generating thermal energy at the interface, the temperature gradient and temperature non-uniformity of the molding material can be reduced.

As a result, the molding apparatus of the present invention makes it possible to improve the fluidity of the molding material during the injection process and the temperature uniformity of the molding material during the cooling process, and to improve the orientation, crystallinity, and crystallinity of the molded product. Non-uniformity of physical properties such as density and shrinkage ratio is greatly reduced, and a high quality molded product without warpage or sink can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a main configuration of a molding apparatus according to an embodiment of the present invention.

FIG. 2 is a control system block diagram in the molding apparatus of FIG.

FIG. 3 is a process diagram illustrating a molding process according to one embodiment of the present invention.

[Explanation of symbols]

11: fixed mold, 12: sprue, 13: movable mold,
14: Arrow indicating the opening and closing direction of the movable mold, 15: Cavity, 16: Halogen lamp, 17: Halogen lamp unit, 18: Halogen lamp unit controller, 19 ...
Moving arm, 20 ... arrow indicating the moving direction of the moving arm,
21: ultrasonic vibrator, 22: horn, 23: ultrasonic vibrator controller, 24a, 24b: temperature sensor, 25: temperature controller, 26: vibration control signal line, 27: movement control signal line,
28: heating device, 29: control panel, 30: molding machine.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-213317 (JP, A) JP-A-3-132323 (JP, A) JP-A-61-44616 (JP, A) JP-A-58-58 134722 (JP, A) JP-A-57-195610 (JP, A) JP-A-6-328451 (JP, A) JP-A-58-140222 (JP, A) (58) Fields investigated (Int. ⁷ , DB name) B29C 33/02-33/08 B29C 45 / 73,45 / 78 B22D 17/22

Claims (5)

(57) [Claims] 1. A mold comprising a fixed mold and a movable mold, heating means for rapidly heating the surface of a portion of the mold where a cavity is formed, Ultrasonic vibrating means for vibrating by sound waves, heating control means for controlling the heating time of the heating means to measure the surface temperature of the mold and set the mold surface to a desired temperature ,
Comprising a vibration control means for controlling the excitation timing and vibration time prior Symbol ultrasonic vibration means, the vibration control means, morphism molding machine
Measures the time with the start point of time as the start point of time measurement, and forms
Vibration starts immediately after filling the cavity with the material
A molding apparatus for controlling the ultrasonic vibrating means so as to cause the vibration . 2. The mold is provided with a temperature sensor for measuring the temperature of the mold in order to control a time during which the mold surface is heated to a desired temperature by a heating means. The molding device according to claim 1, wherein 3. The molding apparatus according to claim 1, wherein the heating control means includes a temperature controller so as to stop heating when the surface temperature of the mold reaches a desired temperature. 4. The heating means moves between the movable mold and the fixed mold while the mold is open to rapidly heat the mold surface.
The molding apparatus according to claim 1, further comprising a moving unit configured to move from between the dies after the surface temperature of the dies reaches a desired temperature and before the dies are closed. 5. The molding apparatus according to claim 1, wherein the heating means is a halogen lamp unit that heats a mold by lighting a halogen lamp.