JP6056487B2 - Injection molding apparatus and injection molding method - Google Patents

Description

  According to the present invention, a liquid resin material (for example, a thermosetting resin) is simply injected into a mold and cured, and a product with a molding accuracy equal to or higher than that of an existing potting process is molded at a low cost. The present invention relates to an injection molding technology that makes it possible.

  Conventionally, as a technique for molding a product in which a predetermined portion is encapsulated with a liquid resin material (for example, a thermosetting resin such as an epoxy resin or a silicone resin) including the molding technique disclosed in Patent Document 1, For example, a technique or a case (container) in which a liquid resin material is placed (potted) in a case (container) in which an object to be molded (also referred to as a molding object) is set, and the resin material is heated and cured. Various molding techniques are known, such as a technique in which a liquid resin material is dropped (potted) at a predetermined site and heated to cure the resin material.

JP 2008-270469 A JP-A-2-303348 JP-A-2-237445

  By the way, in recent years, as electronic and electric devices have higher performance, lighter, thinner, and the like, the reliability of components to be used is further required. Further, along with the price reduction that proceeds at the same time, there is a need for further improvement in the production method of electric and electronic parts. In addition, the needs of users are diversifying, and the need to support high-mix and low-volume production is increasing. In this case, considering the above molding technology, if a case (container) is required, a product with high molding accuracy can be realized, but the number of parts required for the molding process increases, so the molding cost is increased accordingly. As a result, it becomes difficult to meet the demand for cost reduction of products.

  On the other hand, when the case (container) is not required, the number of parts required for the molding process can be reduced, so that the molding cost can be reduced by that amount, but with a high accuracy with respect to a predetermined part. Dropping (potting) resin materials requires a certain level of skill, and in that case, it takes time and effort to achieve a product with high molding accuracy, resulting in a significant increase in product manufacturing costs. Resulting in.

  Here, as disclosed in Patent Documents 2 and 3, a method of flowing a resin material into a mold is already known. However, both methods are methods that allow the resin material to flow into the chamber inside the mold without any gaps. For example, parts such as electrodes, such as molded products such as electric and electronic parts, are not formed outside. In the exposure application, the mold is complicated, or high processing accuracy is required for the electric and electronic parts to be molded, and as a result, it is extremely disadvantageous for lowering the manufacturing cost.

  The present invention has been made to solve the above-described problems, and the object thereof is to enable easy and low-cost molding of products with high molding accuracy even when a case (container) is not required. Is to provide a simple injection molding technique.

In order to achieve such an object, the present invention is an injection molding apparatus for molding a predetermined product by injecting a liquid resin material into a mold and curing it. A holding mechanism for detachably holding the workpiece, a negative pressure mechanism for evacuating the inside of the mold, and a pressurizing mechanism for pressurizing the inside of the mold with air are provided inside the mold. The mold is evacuated in a state where the molded object is detachably held, and after a predetermined amount of resin material is injected, the mold is pressurized with air so that it is not encapsulated by the resin material. A product having a portion at least as a part of the molding is molded.
The present invention also relates to an injection molding method for molding a predetermined product by injecting a liquid resin material into a mold and curing the mold, and a mold can be detachably attached to the mold. A holding mechanism, a negative pressure mechanism that evacuates the mold, and a pressurizing mechanism that pressurizes the mold with air. With the held state, the inside of the mold is evacuated, a predetermined amount of resin material is injected, and the inside of the mold is pressurized with air, so that at least a portion that is not encapsulated by the resin material is at least one of the objects to be molded. The product in the part is molded.
In the present invention, the holding mechanism is configured such that when the product molded in the mold is released, the molding is automatically detached from the holding mechanism by separating and opening the mold. ing.
In the present invention, the mold is configured with a gate for feeding a resin material into the mold, and the gate extends in a divergent shape toward the mold and has a width across the entire mold. It is configured as a narrow gap.

  ADVANTAGE OF THE INVENTION According to this invention, even when a case (container) is unnecessary, the injection molding technique which can shape | mold a product with a high shaping | molding precision easily and in a short time at low cost is realizable.

(a) is sectional drawing which shows schematically the structure of the metal mold | die used for the injection molding technique which concerns on one Embodiment of this invention, (b) is a top view which shows the internal structure of a metal mold | die. Sectional drawing which shows the state which opens a metal mold | die and sets a to-be-molded body in the inside. Sectional drawing which shows the state which made the nozzle contact | abut to the nozzle contact opening in the state which clamped the metal mold | die. Sectional drawing which shows the state which inject | emits the resin material in a metal mold | die. Sectional drawing which shows the state which opens a metal mold | die and demolds a product from the inside. The fragmentary sectional view which shows the structure of the injection molding apparatus applied to one Embodiment of this invention. The fragmentary sectional view which shows the state which sets a to-be-molded object to a metal mold | die. The fragmentary sectional view which shows the state which clamps a metal mold | die. The fragmentary sectional view which shows the state which inject | emits the resin material in a metal mold | die. The fragmentary sectional view which shows the state which seals a nozzle after injection | emission. The fragmentary sectional view which shows the state which demolds a product from a metal mold | die. The fragmentary sectional view which shows the state in the case of encapsulating with respect to a to-be-molded object experimentally and discontinuously.

Hereinafter, an injection molding technique according to an embodiment of the present invention will be described with reference to the accompanying drawings.
In the injection molding technology according to this embodiment, a liquid resin material (for example, a thermosetting resin such as an epoxy resin or a silicone resin) is injected into a mold, and the resin material is heated and cured to obtain a predetermined value. A technology for molding a product (i.e., an injection molding apparatus and an injection molding method) is assumed.

  As shown in FIGS. 1A and 1B, the injection molding apparatus according to the present embodiment is provided with a holding mechanism that detachably holds a workpiece T (see FIGS. 2 and 3) therein. A mold 2 is used. In this case, the mold 2 includes a first mold 2a and a second mold 2b. By superimposing these two molds 2a and 2b, the molding T (for example, A chamber 2c that can accommodate various electric / electronic components such as semiconductors and capacitors is configured (see FIG. 3). Note that the shape, size, size, and the like of the chamber 2c are not particularly limited here because they are set according to, for example, the type and size of the mold 2 and the application (use purpose, use environment). In short, it is only necessary that the molding target T can be accommodated in the chamber 2c when the two molds 2a and 2b are overlapped.

  Further, the holding mechanism separates and opens the mold 2 (specifically, both molds 2a and 2b) when removing the product molded in the mold 2 (see FIG. 5). Thus, the workpiece T is configured to be automatically detached from the holding mechanism. In FIG. 5, as an example when an electronic component is assumed as the article T, a product (finished product) partially encapsulated (for example, a part other than the electrode Et) by the resin material R is shown. In the case of removing the mold, the state in which the electrode Et is automatically detached from the holding mechanism when both the molds 2a and 2b are opened separately is shown.

  As a configuration of the holding mechanism that exhibits such a function, for example, a configuration in which a part of the molding T is hooked, a configuration in which a part of the molding T is locked, and a part of the molding T are press-fitted. Various things such as configurations can be applied. In short, any configuration may be used as long as the whole or a part of the molding T is temporarily (detachably) held and automatically detached when the mold is separated and opened.

  In the present embodiment, as an example, a holding mechanism configured to hook a part of the workpiece T is applied. Such a holding mechanism includes a hook 50 having a hook 50p that can hook a part of the molding T (for example, an electrode Et of an electronic component). It is fixed to the position. The arrangement of the hooking tool 50 is not particularly limited here because it is set according to, for example, the type of the mold 2, the shape and size of the molding T, and the purpose (use purpose, use environment). As an example, the drawings show a configuration in which a holding mechanism (hooking tool 50) is arranged in the first mold 2a.

  Here, when a part of the molding T (for example, the electrode Et of the electronic component) is hooked on the hook 50p of the hook 50, the hook 50p and the mold 2 (specifically, the first mold 2a). ) To the inner wall 2s, a part of the molding T is sandwiched (supported). At this time, by superimposing both molds 2a and 2b, the molding object T is accommodated in the chamber 2c formed therein, whereby the molding object T is molded into the mold 2 ( The chamber 2c) is detachably held (set).

  The mold 2 has a negative pressure mechanism that evacuates the interior of the mold 2 (specifically, the chamber 2c) (in other words, a vacuum state) and pressurizes the interior of the mold 2 with air. And a pressurizing mechanism. In this case, the negative pressure mechanism and the pressurization mechanism may be provided separately for the mold 2, but the negative pressure process and the pressurization process are not performed at the same time. A common negative pressure / pressure pipe 52 for negative pressure treatment and pressure treatment is prepared and connected to the mold 2.

  In the present embodiment, as an example, the negative pressure / pressurization piping 52 is provided in the first mold 2a, and through a negative pressure / pressurization passage 54 extending through the first mold 2a, It communicates in the mold 2 (chamber 2c). Specifically, the negative pressure / pressurization piping 52 is connected to a negative pressure / pressurization switching pump (not shown), and the chamber 2c is evacuated by switching between negative pressure and pressurization, or Or can be pressurized with air.

  Here, the inside of the chamber 2c is evacuated through the negative pressure / pressurized piping 52, so that the resin sent into the chamber 2c together with the air (gas) present in the atmosphere in the chamber 2c. Since air (gas) mixed in the material can be removed (otherwise, gas generation in the chamber 2c can be suppressed), improving the fluidity and transferability of the resin material As a result, a product with high molding accuracy can be realized.

  On the other hand, by pressurizing the inside of the chamber 2c with air via the negative pressure / pressurization pipe 52, the case (container) is used without requiring the case (container) that has been necessary in the past. A product with high molding accuracy equivalent to or higher can be molded easily and in a short time.

  Further, the mold 2 is provided with a gate 2g for feeding a resin material injected from a nozzle 6t described later into the mold 2 (chamber 2c). The gate 2g is formed between the first and second molds 2a and 2b by overlapping them (see FIG. 3), and in the formed state, the part 2p (FIG. 1) to which the nozzle 6t is connected and connected. It is configured as a narrow gap extending from the reference to the mold 2 (chamber 2c) in a divergent shape. In the molding technology field, the gate 2g is referred to as a “fan gate”.

  Further, in the mold 2, the portion 2p to which the nozzle 6t is connected in communication is defined as a nozzle contact formed between the molds 2a and 2b when the first and second molds 2a and 2b are overlapped. The nozzle contact port 2p corresponds to the contact port 2p, and in this state, the nozzle contact port 2p is connected to the chamber 2c through the gate 2g. Further, the nozzle contact port 2p is configured such that the tip of the nozzle 6t can be in close contact (close contact) in an air-tight or liquid-tight manner. It can be fed into the mold 2 (chamber 2c).

Hereinafter, an injection molding method using such a mold 2 will be described.
First, as shown in FIG. 2, after a part of the molding T (for example, the electrode Et of the electronic component) is detachably hooked on the hook 50p of the hook 50, as shown in FIG. The first and second molds 2a and 2b are overlapped and clamped. Thereby, the to-be-molded object T is accommodated in the metal mold | die 2 (chamber 2c). Subsequently, when both the molds 2a and 2b are overlapped, the tip opening Tp of the nozzle 6t is brought into contact with the nozzle contact opening 2p formed between the molds 2a and 2b.

  Next, in this state, as shown in FIG. 4, the inside of the mold 2 (chamber 2c) is evacuated through the negative pressure / pressurized piping 52, and the inside of the mold 2 (chamber 2c) through the nozzle 6t. A predetermined amount of resin material is injected. The predetermined amount is set in a range where the resin material does not reach a part of the molding target T (for example, the electrode Et of the electronic component). At this time, the injected resin material passes through the gate (fan gate) 2g, so that the air (gas) mixed in the resin material is removed, and the mold 2 (chamber 2c) is filled. Thus, a product with high molding accuracy can be molded.

  Next, after the evacuation is stopped, the inside of the mold 2 (chamber 2c) is pressurized with air through the negative pressure / pressurization piping 52, and the pressure is maintained as it is. At this time, the area | region including the site | part in which the holding mechanism (hooking tool 50) is arrange | positioned among the 1st metal mold | die 2a is maintained as a space area | region which a resin material does not reach. In this case, in the heat treatment of the resin material by the mold 2, there is no direct heat transfer from the first mold 2a, but by arranging the first mold 2a close to the resin material, The temperature rises due to the synergistic effect of the radiant heat from the first mold 2a and the convection of the pressurized air, thereby promoting the solidification (curing) of the resin material.

  Thereafter, in a state where the resin material is filled in the mold 2 (chamber 2c) through the gate (fan gate) 2g, heating is performed as necessary until the resin material in the gate 2g is solidified (cured). At the same time, the pressure holding process is continued. Thereby, a product in which at least a part of the molding T (for example, a part other than the electrode Et of the electronic component) is encapsulated with the resin material R is molded (see FIG. 5). In other words, as a feature of the injection molding technique of the present invention, a product having a part that is not encapsulated and sealed by the resin material R as at least a part of the molding T is molded.

  At this time, as shown in FIG. 5, when the mold 2 (specifically, both molds 2a and 2b) are opened separately, a part of the molding T (for example, the electrode Et of the electronic component). Is automatically detached (disengaged) from the holding mechanism (the hook portion 50p of the hook 50), and the product molded in the mold 2 can be easily removed in a short time in the subsequent processing. .

  As described above, according to the present embodiment, by providing the holding mechanism for detachably holding the molding T in the mold 2, the molding T is stably and reliably set in the mold 2. As a result, the degree of freedom in designing the mold 2 can be greatly improved.

  In addition, according to the present embodiment, the negative pressure mechanism and the pressurizing mechanism are provided in the mold 2 so that the case (container) can be removed without requiring the case (container) that has been conventionally required. Products with high molding accuracy equal to or higher than the one used can be molded easily and in a short time, and the number of parts required for the molding process can be reduced by eliminating the need for cases (containers). Therefore, it is possible to reduce the molding cost by that amount, and as a result, it is possible to meet the demand for cost reduction of the product.

  Furthermore, according to the present embodiment, during the heat treatment of the resin material by the mold 2, there is no direct heat transfer from the first mold 2a, but the first mold 2a is moved closer to the resin material. By arranging the components, the temperature rises due to the synergistic effect of the radiant heat from the first mold 2a and the convection of the pressurized air, thereby promoting the solidification (curing) of the resin material.

  In addition, in order to implement | achieve the injection molding process in the above-mentioned metal mold | die 2 and its effect, the injection molding apparatus of this embodiment is a mold clamping unit 4 which clamps the said metal mold | die 2 as shown in FIG. And an injection unit 6 for injecting a resin material into the mold 2 that has been clamped.

First, the mold clamping unit 4 for clamping the mold 2 will be described.
The mold clamping unit 4 includes a first fixed platen 4a and a second fixed platen 4b arranged opposite to each other in parallel, a movable platen 4c capable of reciprocating between the fixed platen 4a and 4b, and a first fixed platen 4a. The clamping actuator 10 that reciprocates the movable platen 4c, the slider 12 that can reciprocate along the second fixed platen 4b, and the reciprocating slider 12 that is provided on the second fixed platen 4b. And a slider actuator 14 to be operated.

  The first and second fixed plates 4a and 4b are positioned at a predetermined interval by the support mechanism 4p, and the movable plate 4c is a guide extended between the fixed plates 4a and 4b. It can move along 4g. In the above-described mold 2, the first mold 2 a is fixed to the movable plate 4 c via the heat insulating plate 16, while the second mold 2 b is connected to the slider 12 via the heat insulating plate 18. It is fixed to. Moreover, each heat insulation board 16 and 18 should just prevent heat being transmitted by conduction, convection, or radiation, for example, and since a commercially available heat insulating material can be utilized, it does not specifically limit here.

  In this case, the mold clamping actuator 10 is connected to the movable platen 4c via the mold clamping rod 10r, and the mold clamping actuator 10 drives the mold clamping rod 10r so as to project and retract. 4c can be reciprocated between the fixed plates 4a and 4b. A slider actuator 14 is connected to the slider 12 via a slider rod 14r, and the slider rod 14r is projected and retracted by the slider actuator 14 so that the slider 12 is moved to the second fixed platen. It can be reciprocated along 4b. In addition, as each actuator 10 and 14, since commercially available things, such as an air pressure, electric power, hydraulic pressure, are applicable, for example, it does not specifically limit here.

  According to such a mold clamping unit 4, the slider 12 is moved by the slider actuator 14, and the second mold 2b on the slider 12 is fixed to the movable platen 4c. The movable platen 4c is moved by the mold-clamping actuator 10 in the state of being opposed to each other, and the first mold 2a on the movable platen 4c is brought close to and overlapped with the second mold 2b. The molds 2a and 2b can be clamped with a preset pressure (see FIG. 3).

Next, an injection unit 6 that injects a resin material into the mold 2 that has been clamped will be described.
The injection unit 6 is provided with an injection cylinder 6s that is connected to the mold 2 (chamber 2c) and includes a nozzle 6t that injects a liquid resin material into the mold 2 (chamber 2c). The injection cylinder 6s is provided with a cylinder body Sb constructed of, for example, four tie bars, and the whole is arranged to be inclined at a predetermined angle θ with respect to the horizontal direction (horizontal plane) H.

  The cylinder body Sb (injection cylinder 6s) has a hollow cylindrical pot portion 6p that accommodates a resin material on the tip side thereof, and the tip of the pot portion 6p (that is, the cylinder body Sb (injection cylinder 6s)). The nozzle 6t described above is provided at the tip of the nozzle. The nozzle 6t is configured to protrude toward the nozzle contact port 2p formed between the molds 2a and 2b when the first and second molds 2a and 2b are overlapped. ing. In this case, it is preferable that the entire nozzle 6t (or at least a region in the vicinity of the tip opening Tp) is formed of a material having low heat transfer (for example, a resin material). Thereby, the influence by the heat transfer from the metal mold | die 2 with respect to the resin material accommodated in the pot part 6p can be reduced.

  The nozzle 6t can be maintained in a state cooled to a predetermined temperature by a cooling device (also referred to as a cooling mechanism) not shown. Here, as a cooling method by the cooling device, for example, various methods such as air cooling and water cooling can be applied. In addition, what is necessary is just to set as the cooling temperature of the nozzle 6t according to various characteristics, such as the kind of resin material, and viscosity.

  According to this, for example, in the case of using a resin material having the characteristic that the viscosity increases as the temperature decreases, the resin material is reduced in viscosity and pressure (for example, about 0.5 MPa, specifically 0.5 MPa). When the nozzle 6t is injected at a pressure in a range of ˜5 MPa, it is possible to prevent the resin material in the nozzle 6t from being hardened while preventing the temperature rise due to heat transfer from the mold 2, and the nozzle 6t When the mold 2 or the sealing mechanism (sealing plate 20) described later is separated, the leakage of the resin material from the nozzle 6t (tip opening Tp) can be reduced.

  Further, the injection molding apparatus is provided with a sealing mechanism for preventing the resin material from leaking from the nozzle 6t in a cooled state. The sealing mechanism includes a sealing plate 20 that seals the nozzle 6t (tip opening Tp) until just before the resin material is injected from the injection unit 6 (nozzle 6t). A sealing actuator 22 is connected to the sealing plate 20 via a sealing rod 22r, and the sealing rod 22r is driven and retracted by the sealing actuator 22 so that the sealing plate 20 is The nozzle 6t (tip opening Tp) can be reciprocated between a position where the nozzle 6t (tip opening Tp) is sealed and a position where the nozzle 6t (tip opening Tp) is avoided. As the actuator 22, for example, a commercially available one such as air pressure, electric power, hydraulic pressure, or the like can be applied, and is not particularly limited here.

  The pot portion 6p is provided with a material supply pipe 24 for continuously supplying a resin material into the pot section 6p. The material supply pipe 24 communicates with a material supply device (not shown). It is connected. The material supply pipe 24 is provided with a backflow prevention function for preventing backflow of continuously supplied resin material.

  Further, the pot portion 6p is provided with a vacuum pipe 26 for evacuating the pot portion 6p (in other words, a vacuum state). The vacuum pipe 26 is connected to a vacuum pump (not shown). Has been. In the present embodiment, as an example, the vacuum pipe 26 is provided on the base end side of the pot portion 6p (on the side opposite to the tip provided with the nozzle 6t, or in a different way, a portion close to a material input port 6f described later). Is provided.

  In this case, the resin supplied into the pot 6p together with the air (gas) present in the atmosphere in the pot 6p by evacuating the pot 6p through the vacuum pipe 26 Resin with excellent fluidity and transferability because air (gas) mixed in the material can be removed (otherwise, generation of gas in the pot portion 6p can be suppressed). The material can be accommodated in the pot portion 6p. The pot portion 6p is provided with a heating / cooling function for heating and cooling the pot portion 6p in order to maintain a constant state (for example, viscosity) of the accommodated resin material.

  In addition, the cylinder body Sb (injection cylinder 6s) is provided with a plunger 28 capable of reciprocatingly moving a resin material accommodated in the pot portion 6p toward the nozzle 6t (tip opening Tp). An injection actuator 30 for reciprocating the plunger 28 is provided. An injection actuator 30 is connected to the plunger 28 via an injection rod 30r. By driving the injection rod 30r to project and retract by the injection actuator 30, the plunger 28 is moved along the pot portion 6p. It can be reciprocated. In addition, as the injection actuator 30, for example, commercially available ones such as air pressure, electric power, and hydraulic pressure can be applied, and therefore, there is no particular limitation here.

  The plunger 28 is provided with a pressure sensor (not shown) that measures the pressure in the injection cylinder 6s (specifically, the pot portion 6p) in a state where the resin material is accommodated. In addition, the plunger 28 has a seal structure formed on the outer periphery near the tip thereof, so that when the plunger 28 is reciprocated along the pot portion 6p, the degree of vacuum in the pot portion 6p is kept constant. It is possible to prevent leakage of the resin material accommodated in the pot portion 6p. In this case, since the existing sealing technology can be applied as the seal structure, there is no particular limitation here, but in the drawing, as an example of the seal structure, along the circumferential direction on the outer periphery of the distal end side of the plunger 28. Two packings 32 that are parallel to each other are laid.

  The entire injection unit 6 is mounted on the movable plate 34, and the injection cylinder 6 s (cylinder body Sb) is placed on the horizontal direction (horizontal plane) H by the support frame 36 on the movable plate 34. It is supported in an inclined state at a predetermined angle θ. Further, a slider 38 is fixed to the movable plate 34, and the slider 38 is configured to be movable along a guide 42 fixed to a fixed base 40. Further, a movable actuator 44 is connected to the movable plate 34 via a movable rod 44r, and the movable plate 44 is moved along the guide 42 by driving the movable rod 44r into and out of the movable plate 44. Can be moved back and forth.

Next, an injection molding method using the above-described injection molding apparatus will be described.
The injection molding method according to the present embodiment includes a step of setting the molding T in the mold 2 (chamber 2c), a step of clamping the mold 2 by the mold clamping unit 4, and a mold clamped 2 (chamber 2c), and a step of injecting a liquid resin material (for example, thermosetting resin such as epoxy resin, silicone resin) by the injection unit 6.

  First, as shown in FIG. 7, the slider 12 is moved by the slider actuator 14 to avoid the second mold 2b fixed on the slider 12 to a predetermined position, and then the first mold. The workpiece T is set in the holding mechanism provided in 2a. At this time, a part of the molding T (for example, the electrode Et of the electronic component) is connected to the hook 50p and the inner wall 2s (see FIG. 2) of the mold 2 (specifically, the first mold 2a). It is in a state of being sandwiched (supported) between.

  Further, a resin material supplied from a material supply device (not shown) is continuously supplied into the pot portion 6p through the material supply pipe 24. At this time, the plunger 28 positioned at the tip of the pot portion 6p is moved backward by the injection actuator 30 based on the supply amount and supply timing of the resin material. Here, since the resin material supplied through the material supply pipe 24 is in a degassed state in the material supply apparatus, it is not necessary to evacuate the pot portion 6p through the vacuum pipe 26.

  In this case, by measuring the resin pressure of the resin material supplied into the pot portion 6p by a pressure sensor (not shown) provided on the plunger 28, while maintaining the pressure in the pot portion 6p constant, Plunger 28 can be retracted. Thereby, even when the pressure at the time of supplying the resin material from a material supply device (not shown) is small, the resin material can be efficiently (smoothly) filled in the pot portion 6p by a preset amount.

  Next, as shown in FIG. 8, the slider 12 is moved by the slider actuator 14 to move the second mold 2b into the mold clamping unit 4, and the first fixed to the movable platen 4c. It faces the mold 2a. Then, the movable platen 4c is moved by the mold clamping actuator 10, and the first mold 2a on the movable platen 4c is brought close to and overlapped with the second mold 2b, whereby both molds 2a, Clamp 2b with a preset pressure.

  At this time, the mold 2 in which the chamber 2c is configured between the two molds 2a and 2b is realized, and the molding T is detachably accommodated and held in the mold 2 (chamber 2c). It will be. At the same time, between the two molds 2a and 2b, the above-described gate 2g (fan gate for feeding the resin material injected from the injection unit 6 (nozzle 6t) into the mold 2 (chamber 2c)) is provided. Will be composed.

  Next, as shown in FIG. 9, the sealing plate 20 is avoided from the nozzle 6 t (tip opening Tp) by the sealing actuator 22, and then the movable plate 34 is moved by the movable actuator 44. The nozzle 6t (tip opening Tp) of the injection unit 6 mounted on 34 is brought into contact with the nozzle contact opening 2p formed between the superimposed molds 2a and 2b (see FIG. 3).

  Subsequently, the inside of the mold 2 (chamber 2c) is evacuated through a negative pressure / pressurization pipe 52 connected to a negative pressure / pressurization switching pump (not shown). At this time, even when heat is transferred from the mold 2 to the nozzle 6t, the nozzle 6t is formed of a material having low heat transfer and is cooled by a cooling device (not shown), so that it is accommodated in the pot portion 6p. There is no influence of heat transfer from the mold 2 on the resin material.

  Then, the resin material accommodated in the pot portion 6p is injected from the nozzle 6t by advancing the plunger 28 while evacuating the mold 2 (chamber 2c) (see FIG. 4). At this time, the injected resin material passes through the gate (fan gate) 2g to remove the air (gas) mixed in the resin material and remove the mold 2 (chamber 2c). ).

  Next, after the evacuation is stopped, the inside of the mold 2 (chamber 2c) is pressurized with air through the negative pressure / pressurization piping 52, and the pressure is maintained as it is. Thereafter, in a state where the resin material is filled in the mold 2 (chamber 2c) through the gate (fan gate) 2g, heating is performed as necessary until the resin material in the gate 2g is solidified (cured). At the same time, the pressure holding process is continued. Thereby, a product in which at least a part of the molding T (for example, a part other than the electrode Et of the electronic component) is encapsulated with the resin material R is molded (see FIG. 5). In other words, as a feature of the injection molding technique of the present invention, a product having a part that is not encapsulated and sealed by the resin material R as at least a part of the molding T is molded.

  Next, as shown in FIG. 10, the movable plate 34 is moved by the sealing actuator 22, thereby separating the nozzle 6 t (tip opening Tp) of the injection unit 6 from the nozzle contact port 2 p and then sealing. The sealing plate 20 is moved by the actuator 22 to seal the nozzle 6t (tip opening Tp). Thereby, the leakage of the resin material from the nozzle 6t (tip opening Tp) can be reliably prevented. During this time, since the nozzle 6t is cooled by a cooling device (not shown), the resin material does not leak.

  As shown in FIG. 11, when the entire resin material filled in the mold 2 (chamber 2 c) is completely solidified (cured), the mold 2 is opened and then the slider 12 is operated by the slider actuator 14. By moving the second mold 2b, the second mold 2b is advanced to a predetermined position, and the product is removed from the second mold 2b at that position. Thereby, the to-be-molded product T as a product (finished product) by which some (for example, parts other than the electrode Et of an electronic component) were encapsulated by the resin material R can be obtained (refer FIG. 5). At this time, the mold may be removed by raising the ejector pin 46p of the ejector device 46.

  As described above, according to the injection molding technique of the present embodiment, a product having a molding accuracy equal to or higher than that in the case where the case (container) is used without requiring the case (container) which has been conventionally required. Can be formed easily and in a short time.

  In addition, according to the injection molding technique of the present embodiment, since the case (container) is not required, the number of parts required for the molding process can be reduced, so that the molding cost can be reduced accordingly. As a result, it is possible to meet the demand for cost reduction of the product.

  Furthermore, according to the injection molding technique of the present embodiment, from the supply of the resin material into the pot portion 6p, the injection of the resin material into the mold 2 (chamber 2c), and the heating, pressure holding, and curing. Since a series of processes can be performed in an environment similar to a vacuumed atmosphere, for example, a product having a good appearance shape free from voids and sink marks can be provided.

  In the above-described embodiment, it is assumed that only the nozzle 6t is maintained in a state cooled to a predetermined temperature by the cooling device. However, the present invention is not limited to this. For example, the sealing of the sealing mechanism The plate 20 may be maintained in a state cooled to a predetermined temperature by a cooling device together with the nozzle 6t.

  In the above-described embodiment, after continuously supplying the resin material from the material supply pipe 24 into the pot portion 6p, the resin material accommodated in the pot portion 6p is sequentially injected from the nozzle 6t (that is, continuously). However, the injection molding technique of the present invention can be applied to other molding methods. As an example, a case where encapsulating with respect to the molding T is performed on a trial / non-continuous basis with a resin material mixed in a beaker or the like in the atmosphere is assumed.

  In order to cope with this case, as shown in FIG. 12, in the injection molding apparatus of the present embodiment, the cylinder body Sb (injection cylinder 6s) has a portion opposite to the pot portion 6p, that is, the cylinder body Sb. A material charging port 6f for charging a resin material toward the inside of the pot portion 6p is provided at a base end side portion of the (injection cylinder 6s).

  Here, when the resin material is introduced from the material insertion port 6f in a state where the plunger 28 is moved backward to the position separated from the pot portion 6p by the injection actuator 30, the resin material is converted into the cylinder body Sb (injection cylinder 6s). And is accommodated in the pot portion 6p. In addition, it is preferable to seal the nozzle 6t (tip opening Tp) with the sealing plate 20 in advance. Thereby, the leakage of the resin material from the nozzle 6t (tip opening Tp) can be prevented.

  Subsequently, the plunger 28 is advanced into the pot portion 6p, and the pot portion 6p is passed through the vacuum pipe 26 at a timing when the inside of the pot portion 6p is sealed by the packing 32 laid on the outer periphery on the distal end side of the plunger 28. The inside is evacuated to remove air (gas) in the pot portion 6p.

  As described above, the cylinder body Sb (injection cylinder 6s) is disposed at a predetermined angle θ with respect to the horizontal direction (horizontal plane) H, and therefore, compared with a case where the cylinder body Sb (injection cylinder 6s) is disposed vertically (vertically). The surface of the resin material accommodated in the pot portion 6p can be widely exposed to a vacuuming atmosphere. Thereby, since the evacuation efficiency with respect to the resin material can be dramatically improved, the air (gas) mixed in the resin material can be more reliably removed.

  Further, after the plunger 28 is advanced into the pot portion 6p, the resin pressure in the pot portion 6p is measured by a pressure sensor (not shown) provided therein, and there is no gap in the pot portion 6p. At this point, the advancement of the plunger 28 is stopped. Since the subsequent processes are the same as those in the embodiment according to FIGS. 7 to 11 described above, description thereof and description of effects thereof are omitted.

  The resin material that can be used in the present invention is preferably a resin composition that is a thermosetting resin that is liquid at 60 ° C. or less and has a viscosity at molding temperature of 3 Pa · s or less. In this case, the main component of the resin material is an epoxy resin, an unsaturated polyester resin, or the like. Depending on the purpose (use), a filler such as silica, a flame retardant, and a functional filler are appropriately blended. Can be used.

2 Mold 2a First mold 2b Second mold 2c Chamber 2g Gate (fan gate)
2p Nozzle contact port 4 Clamping unit 6 Injection unit 6s Injection cylinder 6t Nozzle 50 Hook 50p Hooking portion 52 Negative pressure / pressure piping 54 Negative pressure / pressure passage

Claims (6)

An injection molding apparatus that molds a predetermined product by injecting a liquid resin material into a mold and curing it,
For the mold,
A holding mechanism for detachably holding the molding inside,
A negative pressure mechanism for evacuating the mold,
A pressurizing mechanism for pressurizing the inside of the mold with air,
The mold is evacuated in a state where the object to be molded is detachably held in the mold, and after a predetermined amount of resin material is injected, the mold is pressurized with air to encapsulate the mold with the resin material. An injection molding apparatus characterized in that a product having an unsealed portion at least as a part of a molding is molded.   The holding mechanism is configured such that when the product molded in the mold is removed, the mold is separated and opened, so that the object to be molded is automatically detached from the holding mechanism. The injection molding apparatus according to claim 1, wherein the apparatus is an injection molding apparatus. The mold is configured with a gate for feeding the resin material into the mold,
The injection molding apparatus according to claim 1 or 2, wherein the gate extends in a divergent shape toward the inside of the mold, and is configured as a narrow gap over the whole. An injection molding method for molding a predetermined product by injecting and curing a liquid resin material into a mold,
For the mold,
A holding mechanism for detachably holding the molding inside,
A negative pressure mechanism for evacuating the mold,
A pressurizing mechanism for pressurizing the inside of the mold with air,
The mold is evacuated in a state where the object to be molded is detachably held in the mold, and after a predetermined amount of resin material is injected, the mold is pressurized with air to encapsulate the mold with the resin material. An injection molding method, wherein a product having an unsealed portion at least as a part of a molding is molded.   The holding mechanism is configured such that when the product molded in the mold is removed, the mold is separated and opened, so that the object to be molded is automatically detached from the holding mechanism. The injection molding method according to claim 4, wherein The mold is configured with a gate for feeding the resin material into the mold,
6. The injection molding method according to claim 4 or 5, wherein the gate extends in a divergent shape toward the inside of the mold and is configured as a narrow gap over the whole.

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