JP2012086420A - Injection molding device and injection molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain, in compression molding of a resin injected and filled in a mold, shortening of a molding cycle, reduction of the internal stress of a product, reduction of the load applied to the mold, and improvement in appearance of the product.SOLUTION: A movable die 66 facing a fixed die 54 has a molding hole 68 for receiving a slide core 74, and forms a cavity C between itself and the fixed die 54. A spacer 64 is disposed between a leg portion 62 fixed to a movable side mounting plate 60 and the movable die 66, and a stroke for cavity compression by the slide core 74 is formed by pulling out the spacer 64. When charging of molten resin to the cavity C is completed, compression of a stroke amount corresponding to the pulling portion of the spacer 64 is performed by a mold clamping mechanism 110. At that time, the compression pressure and compression speed are controlled by a control device 140 so that the mold internal pressure does not exceed the pressure at the peak of injection pressure based on a detection result of mold internal pressure by a pressure sensor 80.

Description

  The present invention relates to an injection molding apparatus and an injection molding method using a mold for molding a resin product, and more specifically to compression control after completion of injection of resin into a mold.

  Currently, many resin products are manufactured by injection molding. In general injection molding, resin melted by an injection apparatus is injected and filled at high pressure in a closed mold, and after cooling and solidifying in the mold, a product is taken out. 22A to 22D show an example of a structure of a general injection molding apparatus and a molding process. As shown in FIG. 22A, an injection molding apparatus 600 has a structure in which a mold can be divided into a fixed mold 602 and a movable mold 608, and resin that is injected from a nozzle 606 is provided in the fixed mold 602. A sprue bushing 604 is provided as a passage. Further, a pressure sensor 610 for detecting the pressure in the mold is provided on the end face of the movable mold 608. In the injection molding apparatus 600, as shown in FIG. 22 (B), with the fixed mold 602 and the movable mold 608 closed, the molten resin 612 is put into the mold as shown in FIG. 22 (C). After injecting, cooling and solidifying, the product 620 is taken out as shown in FIG.

  FIG. 21 (A) shows changes over time in the mold pressure in the general injection molding described above. As shown in the figure, the pressure inside the mold reaches a peak when the resin is filled, and then the product shrinks due to cooling and solidification, and the pressure inside the mold gradually decreases. In the illustrated example, the pressure becomes zero 6 seconds after the start of injection. Although the time until the pressure becomes zero varies slightly depending on the type of resin and the product shape, a curve having the same shape as in FIG. Since the resin product manufactured by such injection molding shrinks at the stage of cooling and solidification, in the case of a complicated shape, it is pulled by the thick wall portion, so-called sink is generated on the surface. Or even if it is a simple lump shape, since an internal void will generate | occur | produce, it may become a defective product. Therefore, conventionally, various molding methods have been proposed in order to prevent the occurrence of sink marks and voids.

  One method is injection compression molding. In general injection compression molding, a molten resin is poured in a state where the mold is slightly opened, and then the mold is closed to compress the molten resin, and a molding process is performed to promote the transfer of the mold shape. FIGS. 23A to 23C show an example of a structure and a molding process of a general injection compression molding apparatus. As shown in FIG. 23 (A), the configuration of the injection compression molding apparatus 650 is almost the same as that of the injection molding apparatus 600 shown in FIG. 22. However, in the injection compression molding apparatus 650, as shown in FIG. As shown in the figure, the molten resin 612 is injected into the mold in a slightly opened state so that a gap I is generated between the end surfaces of the fixed mold 602 and the movable mold 608, and immediately after or in synchronization with the injection, The movable mold 608 is moved in the direction of the arrow F23 by an amount corresponding to the opening of the mold (gap I), and the injected resin 612 is compressed (FIG. 23C). FIG. 21 (B) shows changes over time in the mold pressure in the injection compression molding. As shown in the figure, the process proceeds to the compression process immediately after the peak of the injection pressure, reaches the compression pressure peak, and then the pressure in the mold decreases due to cooling and solidification, and finally becomes zero after about 30 seconds.

  Further, there is a molding method using the injection molding apparatus proposed by the present applicant in Japanese Patent Application No. 2009-110173. This molding method is referred to herein as an IMP (in-mold pressing) method and will be described below. The injection molding apparatus of the Japanese Patent Application No. 2009-110173 was developed to improve inconveniences (such as resin leakage and insufficient filling) of conventional injection compression molding in which resin is injected with the parting of the mold open. FIG. 24 shows an outline of the apparatus configuration and the IMP method. An injection molding apparatus 700 shown in FIG. 24A includes a fixed mold 704 fixed to a fixed side mounting plate 702, a movable mold 712 supported by a movable side mounting plate 710, and a molding formed on the movable mold 712. The slide core 720 is slidable in the hole 718, the leg 714 is fixed to the movable mounting plate 710, the spacer 716 is disposed between the leg 714 and the movable mold 712, and the like. . The movable side mounting plate 710 can be stroked toward the fixed side mounting plate 702 by a clamping mechanism (not shown) such as a direct pressure type or a toggle type.

  As shown in FIG. 24B, in the IMP method, the resin 730 is injected with the fixed mold 704 and the movable mold 712 closed at a high pressure, and then the spacer 716 is moved in the stroke direction of the movable mold 712 by a drive mechanism (not shown). The slide core 720 is slid in the molding hole 718 by the space generated by the extraction, and the volume of the cavity C is compressed (re-clamping). FIG. 21 (C) shows changes over time in the mold pressure in the IMP method. As shown in the figure, the spacer 716 is pulled out immediately after the peak of the injection pressure, and after that, the surface of the resin 730 is solidified to some extent in the mold and waits until a solidified layer that can withstand the pressurization is formed. Cavity C is compressed. In the example shown in the figure, compression is performed when time a has elapsed from the start of injection. After reaching the compression pressure peak, the pressure inside the mold decreases due to cooling and solidification, and in the example shown, the pressure inside the mold becomes zero after about 35 seconds. Note that the angle of inclination after the compression pressure peak varies depending on the cooling efficiency, specific heat, material, and the like.

Japanese Patent Application No. 2009-110173

  However, the background art as described above has the following disadvantages. First, in the normal injection compression molding shown in FIG. 23, since the compression in the process of FIG. 23 (C) is performed at a constant pressure or a constant speed, more stress than necessary is applied to the product. Inconveniences such as a long molding cycle occur in order to prevent the adverse effects caused by. For example, in the example of FIG. 21 (B), the pressure becomes zero after 30 seconds, and the time until the pressure becomes zero compared to the above-described normal injection molding (in the case of FIG. 21 (A)). It is getting longer. Basically, the product is taken out when the in-mold pressure becomes zero, but if the product is taken out before that, the pressure is released after the taking out and the product expands. In other words, if the cooling time is shortened, the product is expanded because the internal pressure is taken out in a high state. At this time, it is sufficient that the product expands uniformly, but a slight temperature difference causes deformation. Moreover, since pressure more than necessary is applied to the product and the mold, it is necessary to properly devise the strength and structure of the mold. For example, as shown in FIG. 23D, in the case where the movable mold 608 ′ has a structure composed of divided pieces 608A to 608C, the resin 612 enters the periphery of the insert piece (the divided piece 608A) due to excessive pressure. The burr 614 may be generated.

  On the other hand, in the IMP method using the injection molding apparatus 700 shown in FIG. 24, since the parting can be injected in a closed state at a high pressure using a mold clamping mechanism, there is a degree of freedom in the shape of the product that can be molded and compressed. Although there is an advantage that products and products with uneven thickness can be processed with high precision and voidless, the cavity is compressed after a certain time after injection (time a in Fig. 21 (C)), so the compression pressure can be increased. The higher the time, the longer the time during which the mold internal pressure becomes zero, that is, the molding cycle becomes longer. Further, the inconvenience caused by applying more pressure than necessary to the product and the mold is the same as in the case of the above-described normal injection compression molding. For example, when pressure is applied more than necessary by recompression, burrs 732 are generated between the slide core 720 and the movable mold 712 or between the movable mold 712 and the fixed mold 704 as shown in FIG. Resulting in. For this reason, a highly accurate mold design is required, such as reducing the clearance between the slide core 720 and the movable mold 712. In addition, excessive pressure may cause deformation, buckling, and destruction of the fixed mold 704, the movable mold 712, and the slide core 720.

  The present invention pays attention to the above points. When the resin injected and filled in the mold is compressed and molded, the molding cycle is shortened, the internal stress of the product is reduced, and the load on the mold is reduced. It is an object of the present invention to provide an injection molding apparatus and an injection molding method that are suitable for improving the finish and appearance of a product.

  The injection molding apparatus according to the present invention forms a cavity into which molten resin is injected and filled when the movable mold supported by the movable mold mounting plate and the end face of the fixed mold supported by the fixed mounting plate are brought into contact with each other. A mold to be molded, an injection mechanism for injecting and filling molten resin into the cavity, and opening and closing the mold by causing the movable side mounting plate to stroke with respect to the fixed side mounting plate, and injection of the molten resin by the injection mechanism At the time of filling, a mold clamping mechanism for clamping the parting of the mold with a high-pressure mold, and an extension formed in the stroke direction on the movable mold, opening at an end surface facing the fixed mold, and applying the fixed mold to the end surface One or more molding holes forming at least a part of the cavity when contacted, a slide core partly accommodated in the molding hole and slidable along the molding hole, and the movable Side mounting By moving the spacer arranged between the movable mold and the movable mold, after the mold clamping, the compression core is slid in the direction of compressing the cavity volume in the molding hole while the mold is closed. According to the compression stroke forming means to be secured and the stroke amount obtained by the compression stroke forming means, the slide core is slid along the molding hole while the mold is closed, and the volume of the cavity is increased. A cavity compression mechanism for compression, a pressure sensor for detecting the internal pressure of the cavity, and a compression pressure and a compression speed by the cavity compression mechanism are adjusted based on a detection result of the pressure sensor, thereby controlling a change in the cavity internal pressure over time. And a control means.

  An injection molding apparatus according to another aspect of the present invention is divided into a movable mold and a fixed mold, a mold having a cavity into which molten resin is injected and filled on the divided surface, and the movable mold with respect to the fixed mold. A mold clamping mechanism that opens and closes a mold by stroke, an injection mechanism that injects and fills molten resin into the cavity, a pressure sensor that detects an internal pressure of the cavity, and a mold clamping mechanism based on a detection result of the pressure sensor And a control means for controlling the time-dependent change in the cavity internal pressure by adjusting the compression pressure and the compression speed.

  The injection molding method of the present invention is an injection molding method in which a molten resin is injected and filled in a cavity formed on a dividing surface of a movable mold and a fixed mold, and is compressed and solidified by cooling, and the internal pressure of the cavity is measured by a pressure sensor. It detects, and based on the detection result, compression control is performed along the thermal contraction of the injection-filled resin.

  An injection molding method according to another invention is an injection molding method using the injection molding apparatus according to any one of claims 1 to 12, wherein the compression stroke is formed after injection filling of molten resin by the injection mechanism. When the compression stroke is obtained by the means and the cavity is compressed, the control means controls the compression by the cavity compression mechanism in accordance with the shrinkage of the injection-filled resin based on the detection result of the pressure sensor. It is characterized by that.

  Yet another invention is an injection molding method using the injection molding apparatus according to claim 13 or 14, wherein after the injection filling of the molten resin by the injection mechanism, the control means Based on the detection result, the compression by the mold clamping mechanism is controlled in accordance with the shrinkage of the injection-filled resin.

  One of the main forms is characterized in that, in any of the above-described injection molding methods, the compression pressure and the compression speed are controlled so that the internal pressure of the cavity in the compression process does not exceed the pressure at the injection pressure peak. And The above and other objects, features and advantages of the present invention will become apparent from the following detailed description and the accompanying drawings.

  According to the present invention, when compressing the resin injected into the cavity formed between the fixed mold and the movable mold, the cavity internal pressure (or mold internal pressure) is detected by the pressure sensor, and based on the detection result, Since compression control (adjustment of compression pressure and compression speed, etc.) is performed along the thermal shrinkage of the injected resin, the molding cycle is shortened, the internal stress of the product is reduced, and the load on the mold is reduced. , It is possible to improve the finish and deformation of the product.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Example 1 of this invention, Comprising: (A) is a figure which shows the whole structure of an injection molding apparatus, (B) is a figure which shows the modification of a spacer. Fig. 2 (A) shows the change over time in the mold pressure during the molding process by the IMP method of Example 1, Fig. 2 (B) shows the change over time of the compression pressure, and Fig. 2 (C) shows the compression. FIG. 2 (D) is a diagram showing the change over time in the mold temperature. It is a figure which shows Example 2 of this invention, (A) is sectional drawing which shows the principal part of an injection compression molding apparatus, (B) is sectional drawing which shows the principal part of a modification. FIG. 4 (A) is a graph showing changes over time in the mold pressure during the molding process according to Example 2, and FIGS. 4 (B) to (D) are graphs showing changes over time in the compression pressure and compression speed during the molding process, respectively. It is a figure which shows a different pattern. It is a figure which shows Example 3 of this invention, Comprising: (A) is a figure which shows the whole structure of the injection molding apparatus of Example 3, (B) and (C) are figures which show the effect | action of Example 3. FIG. 6 (A) is a graph showing the change over time in the mold pressure during the molding process according to Example 3, FIG. 6 (B) is a graph showing the change over time in the compression pressure, and FIG. 6 (C) is the change over time in the compression speed. FIG. 6 (D) is a diagram showing changes in mold temperature with time. 7A is an external perspective view showing the shape of a product molded by the injection molding apparatus of Example 3, and FIGS. 7B-1 and 7B-2 show the formation of a surface solidified layer during the molding process. FIG. 7C is a partially enlarged cross-sectional view of (B-1). It is a figure which shows Example 4 of this invention, (A) is an external appearance perspective view which shows the product shape shape | molded by Example 4, (B-1) is a figure which shows the whole structure of the injection molding apparatus of Example 4. FIG. , (B-2) is a partially enlarged view of (B-1), and (C) and (D) are views showing the operation of the fourth embodiment. It is explanatory drawing of a toggle type clamping mechanism, (A) is a figure which shows the structure in the high pressure position of the injection molding apparatus which has a toggle type clamping mechanism, (B) is the structure in the opening position of the said injection molding apparatus FIG. 4C is a diagram showing the relationship of the compression pressure to the mold clamping stroke when performing high-pressure mold clamping from the opening position to the high-pressure position. It is a figure which shows Example 5 of this invention, (A) is a figure which shows the whole structure of an injection molding apparatus, (B) is a figure which shows an effect | action. It is a flowchart which shows the shaping | molding process by the injection molding apparatus of the said Example 5. It is a figure which shows Example 6 of this invention, (A) is a figure which shows the whole structure of an injection molding apparatus, (B) is a figure which shows an effect | action. It is a flowchart which shows the shaping | molding process by the injection molding apparatus of the said Example 6. FIG. It is a figure which shows Example 7 of this invention, (A) is a figure which shows the whole structure of an injection molding apparatus, (B) is a figure which shows an effect | action. It is a flowchart which shows the shaping | molding process by the injection molding apparatus of the said Example 7. It is a figure which shows Example 8 of this invention, (A) is a figure which shows the whole structure of an injection molding apparatus, (B) is a top view which shows a moving plate, (C) is a figure which shows the effect | action of Example 8. is there. It is a flowchart which shows the shaping | molding process by the injection molding apparatus of the said Example 8. It is a figure which shows Example 9 of this invention, (A) is a figure which shows the whole structure of an injection molding apparatus, (B) is a top view of a movable side plate, (C) is a figure which shows the effect | action of Example 9. It is. It is a figure which shows Example 10 of this invention, (A) is an external appearance perspective view which shows the molded article shape shape | molded with the injection molding apparatus of Example 10, (B-1) and (B-2) are comparative examples. FIG. 5C is a sectional view showing the main part of the injection molding apparatus of Example 10 and the molding process. It is sectional drawing which shows the principal part and molding process of the injection molding apparatus of Example 11 of this invention. It is a figure which shows the time-dependent change of the in-mold pressure in background art, (A) shows the case of injection molding, (B) shows the case of injection compression molding, and (C) shows the case of molding in the IMP method. 22A to 22D are diagrams showing a general injection molding process of the background art. 23 (A) to (C) are diagrams showing a general injection compression molding process of the background art, and FIG. 23 (D) is a diagram showing a burr generation location when a nested piece is used. 24 (A) to 24 (C) are diagrams showing a molding process of the IMP method of the background art, and FIG. 24 (D) is a diagram showing a location where a failure occurs. (A) shows the change over time in the volume of the resin during injection molding in normal injection molding, (B) shows the change over time in the injection pressure, and (C-1) shows the overall configuration of the injection molding apparatus Fig. (C-2) is a view showing an air layer generated in the mold due to the shrinkage of the resin.

  Hereinafter, the best mode for carrying out the present invention will be described in detail based on examples.

  First, the basic concept of multistage compression control in the present invention will be described with the background art described above. In the case of normal injection molding, particularly in the case of thick molding, the resin is filled with a high injection pressure to increase the pressure in the mold so that voids and sink marks are not generated. Further, the resin is filled with the volume shrinkage due to cooling and solidification by a method such as delaying the gate seal. FIG. 25 (A) is a diagram showing a change over time in the volume of injected resin in normal injection molding, FIG. 25 (B) is a diagram showing a change over time in injection pressure, and FIG. 25 (C-1) is an injection molding. FIG. 25 (C-2) is a diagram showing the overall configuration of the apparatus, and FIG. 25 (C-2) is a diagram showing an air layer generated inside the mold due to resin shrinkage. As shown in FIG. 25 (A), assuming that no voids or sink marks occur, the product volume in the cavity becomes 100% in a certain time after injection, and then cooling and solidification proceed. For example, when the material shrinkage rate is 3%, the volume is 97% contracted by 3% at the end of solidification. As described above, when the resin shrinks, a gap is formed between the inner surface of the mold and an air heat insulating layer 616 is formed as shown in FIG. 25 (C-2). It takes longer to complete. On the other hand, as shown in FIG. 25 (B), assuming that no voids or sink marks are generated, after the resin is injected into the cavity, the volume of the resin shrinks and solidification is completed, and at the same time, the injection pressure becomes zero. In practice, gate sealing occurs and the resin for volume shrinkage cannot be filled, but it is assumed that voids and sink marks do not occur in thick molding due to large injection pressure. Actually, burrs are generated by a large injection pressure.

  Therefore, the above-described background art injection compression molding has been devised. In injection compression molding, the injection pressure is set under the condition that burrs do not occur in the product, but in actuality sinks and voids are formed due to insufficient pressure, and the insufficient pressure is compensated by compressing. However, if the compression is performed at a constant pressure and speed, the pressure in the mold will also increase and burrs will be generated. The present invention is based on the idea of controlling the shrinkage voids without generating burrs by controlling the compression pressure and compression speed at the time of cavity compression, that is, by controlling the compression along the thermal contraction of the resin. Is based.

  Example 1 is an embodiment in which the compression control is realized by applying the present invention to the IMP method described above. FIG. 1A is a diagram showing the overall configuration of the injection molding apparatus of the present embodiment, and FIG. 1B is a diagram showing a modification of the spacer. Fig. 2 (A) shows the change over time in the mold pressure during the molding process by the IMP method of this embodiment, Fig. 2 (B) shows the change over time of the compression pressure, and Fig. 2 (C) shows the compression speed. FIG. 2 (D) is a diagram showing the change over time in the mold temperature. As shown in FIG. 1A, the injection molding apparatus 50 of the present embodiment is mainly configured by a mold 51 including a fixed mold 54 and a movable mold 66, an injection apparatus 100, and a mold clamping mechanism 110. In addition, a compression stroke forming means for obtaining a stroke for compressing the cavity volume is provided. In this embodiment, the mold clamping mechanism 110 is used as a cavity compression mechanism for applying compression in accordance with the compression stroke amount obtained by the compression stroke forming means.

  First, the mold 51 will be described. On the fixed side of the mold 51, the fixed mold 54 is attached to the fixed side mounting plate 52, and the sprue bush 56 is provided through the fixed side mounting plate 52 and the fixed mold 54. Yes. The sprue bush 56 is connected with a nozzle 108 of an injection apparatus 100 described later for supplying molten resin. The fixed-side template 52 is provided with a cooling hole 58 through which a coolant flows along a surface corresponding to a movable-side forming hole 68 described later. On the other hand, the movable side of the mold 51 has a movable side mounting plate 60, a movable mold 66 whose front end face is opposed to the fixed mold 54, and leg portions 62 and spacers 64 that support the movable mold 66. Yes. The leg portion 62 has a rear end side (left end portion in FIG. 1) fixed to the movable side mounting plate 60, and the spacer 64 is disposed between the front end side and the movable mold 66. . The movable side mounting plate 60 is connected to a rod 116 of a hydraulic cylinder 112 of the mold clamping mechanism 110 described later, and can move forward and backward (stroke) in the direction of arrow F1 toward the fixed side. A molding hole 68 corresponding to the cross-sectional shape of the product to be molded is formed in a substantially central portion of the movable mold 66, and a part of the slide core 74 is slidably accommodated in the molding hole 68. Yes. The movable mold 66 is provided with a cooling hole 78 that surrounds the molding hole 68 and allows the coolant to flow therethrough, and the slide core 74 is also provided with a cooling hole 78 as necessary. Further, a pressure sensor 80 for detecting the internal pressure (in-mold pressure) of the cavity C is provided on the front end surface of the slide core 74. The pressure sensor 80 is connected to a control device 140 described later.

  In the illustrated example, the spacer 64 has a substantially rectangular parallelepiped shape and is fixed to the end of the rod 84 of the hydraulic cylinder 82, and is orthogonal to the stroke direction of the movable die 66 by driving the hydraulic cylinder 82. It can slide in the direction, that is, in parallel with the main surface of the movable mounting plate 60. In this embodiment, the leg 62, the spacer 64, and the hydraulic cylinder 82 constitute a compression stroke forming means for obtaining a cavity volume compression stroke.

  A slide base 70 is disposed in the space inside the leg portion 62 and the spacer 64. The slide base 70 includes a first plate 72A and a second plate 72B. The rear end of the slide core 74 partially accommodated in the molding hole 68 is attached to the second plate 72B with a bolt (not shown). The first plate 72A covers a bolt hole (not shown) appearing on the back surface of the second plate 72B and is seated on the movable mounting plate 60. A spring 76 is provided between the slide base 70 and the movable mold 66, and always urges the slide base 70 toward the movable mounting plate 60. When the movable side mounting plate 60 is stroked in the direction of arrow F1 by driving the mold clamping mechanism 110, the slide core 74 moves in the molding hole 68 through the slide base 70, and the resin 90 in the cavity C can be compressed. It becomes. The movable side mounting plate 60 is provided with a rod hole through which a protruding rod 92 extending from the hydraulic cylinder 94 passes, and the slide core 74 can be slid by pushing the slide base 70 with the protruding rod 92. It has become. For this reason, the slide core 74 exhibits a function of pushing the resin 90 in the cavity C in the compression process, and has a mold release function of pushing the resin as a product from the molding hole 68 after cooling.

  When the movable mold 66 and the fixed mold 54 are brought into contact with each other in a state where the hydraulic cylinder 82 is driven and the spacer 64 is pushed between the leg portion 62 and the movable mold 66, the slide core 74 and the fixed mold 54 in the molding hole 68 are brought into contact. A space between the two becomes a cavity C filled with the resin 90. The axial direction (stroke direction) length of the cavity C in this state, that is, the interval between the front end surface of the slide core 74 and the fixed die 54 is set to be longer than the axial length of the product by a predetermined amount. .

  Next, the injection device 100 will be described. As shown in FIG. 1, the injection apparatus 100 melts the molding material charged from the hopper 104 by the cylinder 102 and melts it from the nozzle 108 at the tip of the cylinder 102 into the cavity C of the mold 51 by the injection mechanism 106. The resin 90 in a state is injected, and its structure is known.

  Next, the mold clamping mechanism 110 will be described. The mold clamping mechanism 110 opens and closes the mold 51 by causing the movable mold 66 to stroke with respect to the fixed mold 54, and can apply sufficient pressure when filling the molding material. Examples of such a mold clamping mechanism include a direct pressure type and a toggle type. In this embodiment, an example of a direct pressure type using a hydraulic cylinder 112 is shown. In the hydraulic cylinder 112, oil chambers 118 and 120 are formed with a piston 114 capable of reciprocating driving in the hydraulic cylinder 112 as a boundary. The oil chambers 118 and 120 have pressure oil inlets 122 and 124, respectively. Is provided. Further, one end of a rod 116 is connected to the piston 114, and the other end of the rod 116 is fixed to the movable side mounting plate 60. The flow path T1 connected to the hydraulic pump 130 branches into two and is connected to the flow paths T2 and T3 via valves V1 and V2, respectively. The flow path T2 is connected to one inlet / outlet 122, and the other flow path T3 is connected to the other inlet / outlet 124.

  Further, in this embodiment, a hydraulic cylinder 82 is used as a drive mechanism for the spacer 64 of the compression stroke forming means, and the hydraulic oil is supplied to and discharged from the hydraulic cylinder 82 by the hydraulic pump 130. Specifically, the flow path T4 connected to the hydraulic pump 130 branches into two and is connected to the flow paths T5 and T6 via valves V3 and V4, respectively. The flow path T5 is connected to one of two oil chambers (not shown) of the hydraulic cylinder 82, and the flow path T6 is connected to the other of the two oil chambers (not shown). Then, by managing the switching of the valves V1 to V4 by the timer 132, the spacer 64 can be slid and the movable side of the mold 51 can be moved back and forth at a desired timing. The timer 132 is connected to the control device 140, and a switching instruction is issued from the control device 140 to the timer 132 according to the detection result of the pressure sensor 80.

  Next, the operation of this embodiment will be described with reference to FIG. Fig. 2 (A) shows the change over time in the mold pressure (cavity pressure), Fig. 2 (B) shows the change over time in the compression pressure, and Fig. 2 (C) shows the change over time in the compression speed (compression speed). FIG. 2 (D) is a diagram showing a change in mold temperature with time. The molding process according to this embodiment is a state in which the movable mold plate 60 and the fixed mold plate 54 are separated from each other with the movable mold mounting plate 60 in the retracted position by the hydraulic cylinder 112 of the mold clamping mechanism 110. The process starts from a state in which the spacer 64 is disposed between the leg portion 62 and the movable die 66. Next, the hydraulic cylinder 112 is operated, the movable die 66 is slid in the direction of the arrow F1 integrally with the movable side mounting plate 60 and moved to the fixed side, and the movable die 66 is brought into contact with the fixed die 54 to be at a constant pressure. Tighten with. The pressure at this time is managed by the control device 140. In this state, a cavity C filled with the resin 90 is formed between the movable mold 66 and the fixed mold 54. Note that the length of the cavity C at this time, that is, the distance between the front end surface of the slide core 74 and the fixed die 54 is equal to the compression stroke amount (or pushing amount) described later than the design value of the axial length of the product. Set long.

  Next, the molten resin 90 is supplied from the injection device 100 connected to the sprue bush 56 on the fixed side. The molten resin is filled into the cavity C from the nozzle 108 through the sprue bush 56 (state shown in FIG. 1A). Even when there is no spring 76 between the slide base 70 and the movable mold 66, the slide core 74 is pushed back by the filled molten resin until the slide base 70 is seated on the movable side mounting plate 60. . At this time, as shown in FIG. 2A, when the injection pressure reaches its peak, the in-mold pressure reaches its peak. After completion of the filling of the molten resin, it is checked whether a predetermined time t has elapsed. During this time, the resin filled in the cavity C is cooled, and a surface solidified layer that can withstand compression is formed on the resin surface.

  When a predetermined time t set in advance elapses, the mold clamping pressure by the mold clamping mechanism 110 is once released, and the hydraulic cylinder 82 is driven to extract all the spacers 64 from between the legs 62 and the movable mold 66 (FIG. 2 ( A) Pull out the spacer). After that, when pressure is again applied by the mold clamping mechanism 110, the slide core 74 slides in the direction of the arrow F1 together with the movable side mounting plate 60 via the slide base 70 by the compression stroke formed by pulling out the spacer 64. The volume of the cavity C is compressed. The thickness of the spacer 64 is such that the distance between the front end surface of the slide core 74 and the fixed die 54 is the length in the axial direction of the product to be molded after compression according to the compression stroke formed by extracting the spacer 64. Is set to be the set value.

  In the compression process after extracting the spacer 64, the control device 140 controls the compression by the mold clamping mechanism 110 based on the detection result of the pressure sensor 80. That is, as shown in FIG. 2 (A), the compression pressure and the compression speed of the mold clamping mechanism 110 are controlled so that the pressure inside the mold does not exceed the pressure at the peak of the injection pressure. Specifically, the compression pressure is controlled as shown in FIG. 2 (B), and the compression speed is controlled as shown in FIG. 2 (C). By controlling the compression so as to follow the thermal contraction of the resin 90 without applying an excessive pressure in this way, it is possible to control sink marks and voids without generating burrs.

  When the cooling process by the compression control as described above is completed, the movable side mounting plate 60 is returned to the retracted position by the hydraulic cylinder 112 of the mold clamping mechanism 110 and the mold is opened. At the retracted position of the movable side mounting plate 60, the fixed side template 54 and the movable side template 66 are separated farther than the axial length of the product. Thereafter, when the slide base 70 is pushed out by the protruding rod 92, the slide core 74 attached to the slide base 70 slides in the molding hole 68, and the cooled and molded product is pushed out from the molding hole 68. Thereby, the resin product is released from the mold, and one molding is completed. The determination of the elapse of the predetermined time in the above steps is performed by the timer 132, and the control device 140 issues a predetermined control signal based on the determination.

  In the method of the present embodiment, when the slide core 74 is slid, a folding phenomenon may appear on the side surface of the product. This is a phenomenon that occurs when the surface solidified layer of the resin 90 shifts the inner wall of the cavity C. In order to suppress this phenomenon, it is necessary to apply compression in synchronization with the temperature change of the mold 51. The idea of changing the mold temperature in the molding cycle is known as "weldless molding", "heat and cool molding", and "heat cycle molding", but was developed for the purpose of basically eliminating the weld line. It is a construction method. These methods are effective for a product having a relatively thin thickness, but cannot provide a sufficient effect for a product having a thick wall as in the present embodiment.

  Therefore, in this embodiment, in the compression control described above, as shown in FIG. 2 (D), the mold temperature is set high at the time of injection, and the mold temperature is lowered simultaneously with cooling. By controlling the temperature, the quality of the product is further improved. In the illustrated example, the mold temperature is set to 120 ° C. during injection, the temperature is gradually lowered during pressurization (cavity compression), and the mold temperature is set to 30 ° C. during mold release. Control is being done. In order to control the temperature, it is necessary not only to circulate the coolant through the cooling holes 58 and 78 but also to heat the entire mold 51 by a heating means (such as a heater) (not shown). By connecting the means to the control means 140, it is possible to perform desired control according to the change in the mold pressure. By controlling the mold temperature in this manner, pressure drop when the spacer 64 is pulled out can be avoided, and compression control as shown in FIG. 2 (A) can be easily performed. A foldable phenomenon does not occur on the surface, and a good-looking product can be made. In addition, what is necessary is just to perform control of the metal mold | die temperature demonstrated here as needed.

Thus, according to the first embodiment, there are the following effects.
(1) A pressure sensor 80 for detecting the internal pressure (in-mold pressure) of the cavity C is provided, and the mold clamping is performed based on the detection result of the pressure sensor 80 so that the in-mold pressure does not exceed the peak pressure of the injection pressure. Since the control device 140 controls the compression pressure and compression speed of the mechanism 110, it is possible to control sink marks and voids without generating burrs.
(2) Since more pressure than necessary is not applied, the time for cooling and solidification is shortened and the molding cycle is shortened.
(3) The product can be prevented from being subjected to excessive pressure and the internal stress of the product can be suppressed.
(4) By controlling the compression pressure to a low level, it works effectively to prevent product quality and post-deformation.
(5) It is possible to prevent deformation of the fixed die 54 and the movable die 66 due to excessive compressive force, buckling of the slide core 74, deformation of pieces around the slide core 74, and generation of burrs.
(6) Since the pressure between the slide core 74 and the movable mold 66 does not have to be reduced by controlling the pressure in the mold to be low, high mold accuracy is not required.
(7) By performing the compression control in synchronization with the temperature change of the mold 51 as necessary, it is possible to suppress the folding phenomenon of the product surface and further improve the product quality in terms of appearance. It becomes.

  Next, Embodiment 2 of the present invention will be described with reference to FIGS. In the first embodiment, the present invention is applied to the IMP method. In this embodiment, an example in which the present invention is applied to the general injection compression molding described in the background art described above will be described. FIG. 3 (A) is a cross-sectional view showing the main part of the injection compression molding apparatus of the present embodiment, and FIG. 3 (B) is a cross-sectional view showing the main part of the modification. FIG. 4 (A) is a graph showing the change over time in the cavity internal pressure (in-mold pressure) during the molding process according to this embodiment, and FIGS. 4 (B) to 4 (D) show the compression pressure and compression speed during the molding process, respectively. It is a figure which shows the pattern from which a time-dependent change differs. The injection compression molding apparatus 650A of the present embodiment has basically the same configuration as the above-described background art injection compression molding apparatus 650, and the mold can be divided into a fixed mold 602 and a movable mold 608. The fixed mold 602 is provided with a sprue bush 604 serving as a passage for the molten resin 612 injected from the nozzle 606. In addition, a pressure sensor 610 for detecting the mold internal pressure (internal pressure of the cavity C) is provided on the end surface of the movable mold 608. The movable mold 608 can be stroked in the direction of the arrow F3 toward the fixed mold 602 by, for example, a direct pressure type or toggle type mold clamping mechanism 142. The mold clamping mechanism 142 and the pressure sensor 610 are connected to the same control device 140 as in the first embodiment.

  In the injection compression molding apparatus 650A, as shown in FIG. 3 (A), the direction of the arrow F3 until the mold clamping mechanism 142 is slightly opened so that a predetermined gap I is generated between the end surfaces of the fixed mold 602 and the movable mold 608. And the molten resin 612 is injected into the cavity C. Immediately after that, or while injecting, the movable mold 608 is moved again in the direction of arrow F3 by the mold clamping mechanism 142 by an amount corresponding to the opening of the mold (gap I), and the injected resin 612 is compressed. In this compression step, the control device 140 controls the compression and speed of the compression by the mold clamping mechanism 142 according to the detection result of the pressure sensor 610. FIG. 4 (A) shows the change over time in the mold pressure in the compression step. In injection compression molding, the process proceeds to the compression process immediately after the peak of the injection pressure. At this time, the control device 140 controls the compression pressure and compression of the mold clamping mechanism 142 so that the pressure inside the mold does not exceed the pressure at the injection pressure peak. Control the speed. Specifically, in the process of cooling and solidifying the resin 612, for example, the compression pressure and the compression speed are controlled so as to show one of the patterns shown in FIGS. By controlling so as not to exceed the pressure at the time of the pressure peak, it is possible to control compression along the thermal contraction of the resin 612 without applying excessive pressure, and it is possible to control sink marks and voids without generating burrs.

  Such compression control is particularly effective when the movable mold 608 ′ has a divided piece structure composed of a plurality of divided pieces 608A to 608C, as in an injection compression molding apparatus 650B shown in FIG. . If the above-described compression control is not performed, the pressure in the mold rises more than necessary, so that the resin 612 enters from the piece alignment of the divided piece (entry piece) 608A and the surrounding divided piece (fixed piece) 608B. Therefore, it is necessary to reduce the clearance for piece alignment. On the other hand, in this embodiment, since the occurrence of burrs is suppressed by the compression control, the clearance for aligning the divided pieces 608A and the divided pieces 608B can be increased, that is, the mold design accuracy can be roughened. .

Thus, according to Example 2, there are the following effects.
(1) A pressure sensor 610 for detecting the internal pressure (in-mold pressure) of the cavity C is provided, and the mold clamping is performed based on the detection result of the pressure sensor 610 so that the in-mold pressure does not exceed the peak pressure of the injection pressure. Since the compression pressure and the compression speed by the mechanism 142 are controlled by the control device 140, sink marks and voids can be controlled without generating burrs.
(2) Since the pressure more than necessary is not applied, the cooling and solidifying time is shortened and the molding cycle is shortened.
(3) The product can be prevented from being subjected to excessive pressure and the internal stress of the product can be suppressed.
(4) By controlling the compression pressure to a low level, it works effectively to prevent product quality and post-deformation.
(5) Since the generation of burrs can be suppressed even if the movable type has a divided piece structure, high accuracy is not required for piece alignment.

  Next, Embodiment 3 of the present invention will be described with reference to FIGS. In this example, as in Example 2 described above, the present invention is applied to the IMP method and has a configuration suitable for forming uneven products. FIG. 5A is a diagram showing the overall configuration of the injection molding apparatus of this embodiment, and FIGS. 5B and 5C are views showing the operation of this embodiment. 6A is a diagram showing the change over time in the mold pressure during the molding process according to this embodiment, FIG. 6B is a diagram showing the change over time in the compression pressure, and FIG. 6C is the change over time in the compression speed. FIG. 6 (D) is a diagram showing a change in mold temperature with time. FIG. 7 (A) is an external perspective view showing the shape of a product molded by the injection molding apparatus of this embodiment, and FIGS. 7 (B-1) and 7 (B-2) show the formation of a surface solidified layer during the molding process. FIG. 7C is a cross-sectional view showing a partially enlarged view of (B-1). In addition, the same code | symbol shall be used for the component which is the same as that of Example 1 mentioned above, or respond | corresponds. As shown in FIG. 7A, the product 180 formed in this embodiment has a substantially T-shaped cross section including a thick convex portion 184 and a thin portion 186.

  As shown in FIG. 5A, the injection molding apparatus 150 of the present embodiment has the same structure as that of the first embodiment on the fixed side. On the other hand, on the movable side, the distal end portion 152A of the leg portion 152 having a substantially L-shaped cross section is fixed to the rear end side of the movable mold 66, and between the leg rear end portion 152B and the movable side mounting plate 60, The spacer 64 is disposed. The spacer 64 is formed with a screw hole (not shown). By screwing a screw shaft 174 rotated by a hydraulic motor 172 into the screw hole, the spacer 64 is fixed to the movable side mounting plate 60 and the leg portion 152. A stroke for compressing the cavity C by the slide core 160 described later is secured. In other words, in this embodiment, the compression stroke forming means is configured by the hydraulic motor 172, the screw shaft 174, and the spacer 64. The hydraulic motor 172 is connected to the control device 140.

  The slide core 160 accommodated in the molding hole 68 of the movable die 66 has a divided structure composed of an inner slide core 162 and an outer slide core 164 arranged outside thereof, and each compresses the cavity C at different timings. It is possible. The end 162A of the inner slide core 162 and the end 164A of the outer slide core 164 face the end face of the fixed mold 54 to form a cavity C. The other end 162B of the inner slide core 162 is fixed to the first slide base 166 disposed inside the leg 152 and the spacer 64, and the other end 164B of the outer slide core 164 is The second slide base 170 is fixed. The first slide base 166 is provided with a compression stroke amount adjusting screw 168 whose tip protrudes toward the second slide base 170. The distance S1 between the tip of the compression stroke amount adjusting screw 168 and the second slide base 170 defines the difference between the compression amount by the inner slide core 162 and the compression amount by the outer slide core 164. It can be adjusted according to the condition.

  Further, a pressure sensor 80 for detecting the internal pressure of the cavity C is provided on the end 164 A side of the outer slide core 164, and the pressure sensor 80 is connected to the control device 140. Furthermore, the movable side mold plate 60 is connected to a direct pressure type mold clamping mechanism 176, and the mold clamping mechanism 176 can be stroked in the direction of arrow F5. The mold clamping mechanism 176 is also connected to the control device 140.

  Next, the operation of this embodiment will be described. The concept of compression control according to the present embodiment is basically the same as that of the first embodiment described above, except for the difference in compression timing between the inner slide core 162 and the outer slide core 164. The molding process starts from a state in which the movable side mounting plate 60 is moved to the retracted position by the mold clamping mechanism 176 and the spacer 64 is disposed between the movable side mounting plate 60 and the leg 152, and the movable mold is moved by the mold clamping mechanism 176. 66 is moved toward the fixed mold 54 in the direction of arrow F5, and the movable mold 66 is brought into contact with the fixed mold 54 and clamped with a constant pressure. The pressure at this time is managed by the control device 140.

  Next, molten resin is injected and filled into the cavity C from the injection device 100 via the sprue bush 56 on the fixed side. At this time, as shown in FIG. 6A, when the injection pressure reaches its peak, the in-mold pressure reaches its peak. After completion of the filling of the molten resin, the elapse of a predetermined time t is waited until a surface solidified layer that can withstand compression is formed on the surface of the resin filled in the cavity C. When a predetermined time set in advance elapses, the mold clamping pressure by the mold clamping mechanism 176 is once released, and the hydraulic motor 172 is driven to pull out the spacer 64 from between the leg portion 152 and the movable side mounting plate 60. Then, a compression stroke is obtained for the movable side mounting plate 60 to slide in the direction of arrow F5 by an amount corresponding to the thickness S2 of the spacer 64 shown in FIG.

  Here, when the pressure by the mold clamping mechanism 176 is applied again, out of the compression stroke (thickness S2) formed by pulling out the spacer 64, first, the tip of the compression stroke amount adjusting screw 168 and the second slide base 170 are used. The inner slide core 162 slides in the direction of arrow F5 through the movable side mounting plate 60 and the first slide base 166 by a distance corresponding to the interval S1, and compresses the central portion of the resin 90 in the cavity C. This state is shown in FIG. Even after the tip of the compression stroke amount adjusting screw 168 comes into contact with the movable die 66, if the compression by the mold clamping mechanism 176 is continued, the compression stroke amount adjusting screw 168 and the first screw are adjusted in parallel with the compression by the inner slide core 162. The cavity C is also compressed by the outer slide core 164 via the two slide bases 170. The compression by the outer slide core 164 continues until the movable side mounting plate 60 contacts the leg rear end portion 152B, and is completed when the movable side mounting plate 60 strokes a distance corresponding to the thickness S2 of the spacer 64 (see FIG. 5 (C)).

  In the compression process after extracting the spacer 64, the control device 140 controls the compression by the mold clamping mechanism 176 in accordance with the detection result of the pressure sensor 80. That is, as shown in FIG. 6 (A), the compression pressure and compression speed of the mold clamping mechanism 176 are set so that the pressure inside the mold does not exceed the pressure at the peak of the injection pressure during compression by the inner slide core 162. The mold clamping mechanism is controlled so that the pressure inside the mold decreases as indicated by the solid line in FIG. 6A after the compression by the outer slide core 164 is applied (the timing of the one-dot chain line in FIG. 6A). 176 controls the compression pressure and speed. Specifically, the compression pressure is controlled as shown by a solid line in FIG. 6B, and the compression speed is controlled as shown by a solid line in FIG. 6C. By controlling the compression so as to follow the thermal contraction of the resin 90 without applying an excessive pressure in this way, it is possible to control sink marks and voids without generating burrs. The mold opening / releasing operation after the completion of the compression controlled cooling process is the same as in the first embodiment. In the above description, the control is performed so that the pressure inside the mold does not exceed the pressure at the peak of the injection pressure. For example, as shown by the dotted line in FIG. The pressure in the mold may temporarily exceed the peak pressure. Control of the compression pressure and compression speed at this time is performed, for example, as shown by dotted lines in FIGS. 6 (B) and 6 (C).

  In the present embodiment, the portion corresponding to the thick convex portion 184 of the product 180 is first compressed, and the thin portion 186 is compressed later, so that the entire surface of the product 180 is finally compressed. If the configuration is such that only the convex portion 184 is compressed by the inner slide core 162 as shown by the arrow F7a in FIG. 7 (B-1), the arrow in FIG. As shown by F7b, the surface solidified layer 182 flows, and as shown in FIG. 7C, a biting portion 188 of the surface solidified layer 182 is generated between the thin portion 186 which is not compressed. This means that there is a discrepancy between the compression timing and the formation speed of the surface solidified layer 182. In this embodiment, the slide core 160 is divided into the inner slide core 162 and the outer slide core 164, and the compression timing is increased. This adjustment can be reduced. Further, as in the example shown in FIG. 7B-2, the thin portion 186 is first compressed by the outer slide core 164 in the direction of the arrow F7a, and then the thick portion (the convex portion 184) is compressed by the inner slide core 162. In the case of compressing at, the biting portion 188 of the surface solidified layer 182 shown in FIG. 7C can be eliminated, depending on the relationship between both compression strokes.

  Further, in addition to the configuration of the slide core 160, the biting phenomenon of the surface solidified layer 182 may be minimized by controlling the temperature of the mold as in the first embodiment. Specifically, when the mold temperature is adjusted as shown in FIG. 6D, the biting phenomenon can be suppressed and the occurrence of defects such as insufficient strength of the product 180 can be prevented. In the present embodiment, both the convex portion 184 and the thin portion 186 of the product 180 are finally compressed, but the thin portion 186 is extremely thin, and the compression by the outer slide core 164 is performed. If inconvenience such as insufficient strength occurs, the same effect of suppressing the biting phenomenon can be obtained by combining the compression control only by the inner slide core 162 and the above-described mold temperature control.

  According to this embodiment, in addition to the effects of the first embodiment described above, the slide core 160 has a split piece structure of the inner slide core 162 and the outer slide core 164, and these compress the cavity C by the compression stroke amount adjusting screw 168. Since the timing to perform is shifted, even if the product is uneven, it is possible to obtain an effect that appropriate compression according to the shape of the product 180 is possible. Moreover, in the case of uneven thickness products, the timing of cooling and solidification varies depending on the thickness of the part, and compression conditions corresponding to the timing are required, but even if it is difficult due to the structure of the mold, as in this embodiment In addition, by controlling the cooling and solidification to some extent by the mold temperature, it is possible to widen the range of compression conditions and to expand the applicable product shape. Further, by combining the control of the mold temperature, it is possible to manufacture a product with improved mold transferability.

  Next, Embodiment 4 of the present invention will be described with reference to FIG. The present embodiment is an example suitable for molding an uneven product having a shape different from that of the third embodiment. 8A is an external perspective view showing the shape of a product molded by this embodiment, FIG. 8B-1 is a diagram showing the overall configuration of the injection molding apparatus of this embodiment, and FIG. 8B-2 FIG. 8 is a partially enlarged view of (B-1), and FIGS. 8C and 8D are views showing the operation of this embodiment. As shown in FIG. 8A, the product 190 molded according to the present embodiment has a shape in which a thin protrusion 194 is connected to a side surface of a thick main body 192 by a connecting portion 196.

  In the injection molding apparatus 200 of the present embodiment, the structure on the fixed side is the same as that of the third embodiment. On the other hand, the movable mold 66A is formed with a molding hole 68 in which the first slide core 206 is accommodated and a molding hole 212 in which the second slide core 220 is accommodated. These forming holes 68 and 212 are connected on the fixed die 54 side by a branch recess 202 corresponding to the connecting portion 196 of the product 190. The first slide core 206 compresses a portion corresponding to the product main body 192, and the second slide core 220 compresses the protruding portion 194 of the product 190. A pressure sensor 80 is provided on one end 206 </ b> A side of the first slide core 206, and the pressure sensor 80 is connected to the control device 140. On the other hand, the other end 206 </ b> B side of the first slide core 206 is supported by the slide base 208. The slide base 208 is provided with a compression stroke amount adjusting screw 210 at a position corresponding to the second slide core 220.

  As shown in FIG. 8B-2, the molding hole 212 has a shape in which a small diameter portion 214A, a large diameter portion 216, and a small diameter portion 214B are formed in order. The second slide core 220 has a flange 222, and the end 220A side is accommodated in the small diameter portion 214A, and the other end 220B side is accommodated in the small diameter portion 214B. The large diameter portion 216 accommodates the flange portion 222 and a spring 224 that urges the flange portion 222 toward the small diameter portion 214B and the edge portion 218 of the large diameter portion 216. The end of the compression stroke amount adjusting screw 210 can come into contact with the end 220B of the second slide core 220 by pulling out the spacer 64. A leg portion 204 is fixed to the rear end side of the movable die 66 </ b> A, and a spacer 64 that can be pulled out by a hydraulic cylinder 172 is provided between the leg portion 204 and the movable side mounting plate 60.

  In this embodiment, after the resin 90 is injected and filled into the cavity C shown in FIG. 8 (B-1), the mold clamping pressure by the mold clamping mechanism 176 is once released, and the hydraulic motor 172 is driven to move the spacer 64 to the leg. When all the portions 204 and the movable side mounting plate 60 are extracted, a space for moving the movable side mounting plate 60 in the direction of the arrow F8 is obtained by an amount corresponding to the thickness S4 of the spacer 64. Here, when pressure is applied again by the mold clamping mechanism 176, among the compression stroke (thickness S4) formed by pulling out the spacer 64, first, the tip of the compression stroke amount adjusting screw 210 and the second slide core 220 are used. The first slide core 206 slides in the direction of arrow F8 through the movable side mounting plate 60 and the slide base 208 by a distance corresponding to the distance S3, and the 90 thick portion of resin in the cavity C (of the product 190). The portion corresponding to the main body 192) is compressed. This state is shown in FIG.

  Even after the tip of the compression stroke amount adjusting screw 210 comes into contact with the second slide core 220, if the compression by the mold clamping mechanism 176 is continued, the compression stroke amount adjusting screw is parallel to the compression by the first slide core 206. The thin portion of the cavity C (the portion corresponding to the protruding portion 194 of the product 190) is also compressed by the second slide core 220 via 210. The compression by the second slide core 220 is completed when the movable side mounting plate 60 comes into contact with the rear end of the leg portion 204, that is, when the movable side mounting plate 60 strokes a distance corresponding to the thickness S4 of the spacer 64 ( FIG. 8 (D)). The operations and effects of the present embodiment are basically the same as those of the third embodiment except for the shift in the compression timing by the first slide core 206 and the second slide core 220.

  Next, Embodiment 5 of the present invention will be described with reference to FIGS. In the first to fourth embodiments described above, a direct pressure type mechanism using hydraulic pressure is used as the mold clamping mechanism. However, a toggle type electric mold clamping mechanism is widely used as the mold clamping mechanism of the injection molding apparatus. Has been. In the direct pressure type, since the compression control that is a feature of the present invention can be performed relatively easily, the mold clamping mechanism can be used as a cavity compression mechanism. However, in the case of a toggle type mold clamping mechanism, The pressure control may be difficult due to the structural problem, and a cavity compression mechanism is required independently of the toggle type clamping mechanism.

  FIG. 9 is an explanatory diagram of a general toggle type mold clamping mechanism, (A) is a diagram showing a structure of the injection molding apparatus having a toggle type mold clamping mechanism in a high pressure position, and (B) is the injection molding apparatus. FIG. 6C is a diagram showing the relationship between the compression pressure and the mold clamping stroke when a high-pressure mold clamping is performed from the dimension opening position to the high pressure position with a 100-t injection molding apparatus. As shown in FIGS. 9A and 9B, in the injection molding apparatus 300 using the toggle type mold clamping mechanism 310, a moving plate 308 is disposed between a pair of fixed plates 302 and 304. The moving plate 308 can be stroked in the direction of arrow F9 along a plurality of guide rods 306 provided between the pair of fixed plates 302 and 304. A rod 312 of a hydraulic motor 320 is connected to the moving plate 308 via a cam mechanism including a plurality of links 314A to 314F. The rod 312 passes through the fixed plate 304. The fixed-side mounting plate 52 that supports the fixed mold 54 is fixed to the fixed plate 302, and the movable-side mounting plate 60 that supports the movable mold 66 is supported by the moving plate 308.

  Such a toggle-type injection molding apparatus 300 has the following inconveniences, and high-precision compression control cannot be performed using the mold clamping structure as it is. First, as shown in FIG. 9 (B), when the mold is opened with the mold opened (dimension opening position), the clamping force at the cam is weak, and the mold holding force is not released and the injection pressure is lost. The mold opens. Second, in order to compress from the open state, the clamping force of the toggle type is insufficient, and the compression stroke is limited. Further, the compression pressure varies depending on the compression position, and the pressure cannot be set arbitrarily. For example, when compression is performed from the opening position shown in FIG. 9 (B) and compression is performed up to the high pressure clamping position shown in FIG. 9 (A), the pressure distribution as shown in FIG. The pressure at depends on the drive system (such as the hydraulic motor 320), and a high compression force cannot be obtained. Thirdly, in order to use the toggle type mold clamping mechanism in the IMP method described above, it is necessary to compress the cavity from the high pressure mold clamping position shown in FIG. In the toggle type, it is impossible to further move the position of the moving plate 308 shown in FIG. 9A to the fixed plate 302 side.

  Therefore, in this embodiment, in order to perform stable compression control even with the toggle type, a cavity compression mechanism independent of the mold clamping mechanism is provided. FIG. 10 (A) shows the overall configuration of the injection molding apparatus of Example 5, and FIG. 10 (B) shows the operation of this example. FIG. 11 shows a flowchart of the molding process in the IMP direction using the injection molding apparatus of this embodiment. The injection molding apparatus 350 shown in FIGS. 10 (A) and 10 (B) has the same structure as that of the third embodiment shown in FIG. A compression unit 352 is provided as a mechanism for causing the core 160 to stroke. The compression unit 352 includes a plate 354 slidable in the stroke direction along a plurality of guide pins 356 erected on one main surface of the moving plate 308, and a spring that biases the plate 354 toward the moving plate 308. 358, a movable unit 360, a fixed unit 362, and a hydraulic motor 366. A rod 364 of the hydraulic motor 366 is connected to the movable unit 360 and is slidable in parallel with the main surface of the moving plate 308. The fixing unit 362 is fixed to the back surface of the plate 354. Tapers 360A and 362A are formed on the contact surfaces of the movable unit 360 and the fixed unit 362, respectively.

  Therefore, when the spacer 64 is pulled out from the state in which a part of the movable unit 360 is pulled out (the state shown in FIG. 10A) and the movable unit 360 is pushed in by driving the hydraulic motor 366, the state shown in FIG. Then, the plate 354 slides in the direction of the arrow F10 with respect to the moving plate 308. Then, the movable side mounting plate 60 and the movable die 66 supported by the plate 354 also move in the direction of the arrow F10 by the compression stroke obtained by pulling out the spacer 64, so that the resin 90 in the cavity C is compressed. The The hydraulic motor 366 of the compression unit 352 is connected to the control device 140 together with the hydraulic motor 320 of the mold clamping mechanism 310 and the hydraulic motor 172 of the spacer 64, and the pressure in the mold is determined according to the detection result of the pressure sensor 80. Are controlled to exhibit desired characteristics.

  Next, the operation of this embodiment will be described. First, the hydraulic motor 320 is driven in a state where a part of the movable unit 360 is pulled out, and the high pressure mold clamping is performed by the mold clamping mechanism 310 (step S10 in FIG. 11), and the molten resin 90 is supplied from the nozzle 108 to the cavity C. Injection is performed (step S12) (state shown in FIG. 10A). Then, the hydraulic motor 320 is driven to open the mold (step S14), and then the hydraulic motor 172 is driven to pull out the spacer 64 (step S16) to obtain a compression stroke. Subsequently, after the hydraulic motor 320 is operated and high pressure clamping is performed again (step S18), the hydraulic motor 366 of the compression unit 352 is operated to push the movable unit 360, and the compression stroke obtained in step S16 is obtained. Only the movable side mounting plate 60 and the slide core 160 are moved, and the cavity C is compressed (step S20) (state shown in FIG. 10B). In the compression process at this time, the control device 140 performs the same control as in the first embodiment. When the cooling is finished, the hydraulic motor 320 is operated to open the mold (step S22), the product is released from the cavity C, and the molding is finished. As described above, according to the present embodiment, the compression unit 352 for compressing the cavity C is independently provided. Therefore, even when the toggle type mold clamping mechanism 310 is used, an appropriate pressure can be obtained. Control can be performed stably.

  Next, Embodiment 6 of the present invention will be described with reference to FIGS. This embodiment is also an example provided with a cavity compression mechanism independent of a toggle type mold clamping mechanism as in the fifth embodiment (the same applies to the following seventh to ninth embodiments). FIG. 12A is a diagram showing the overall configuration of the injection molding apparatus of this embodiment, FIG. 12B is a diagram showing the operation, and FIG. 13 is an IMP method using the injection molding apparatus of this embodiment. It is a flowchart which shows the shaping | molding process by. In the injection molding apparatus 380 shown in FIG. 12, a plurality of guide pins 356 are erected on a plate 382 fixed to one main surface of the moving plate 308, and the plate 354 slides along the guide pins 356. Supported as possible. The plate 382 is provided with a thin hydraulic cylinder 384 whose rod 386 is connected to the plate 354. The thin hydraulic cylinder 384 is connected to the control device 140, and compression control is performed when the thin hydraulic cylinder 384 compresses the cavity.

  In this embodiment, with the rod 386 of the thin hydraulic cylinder 384 retracted, high pressure clamping (step S10) and injection of the resin 90 (step S12) (step S12) (FIG. 12A) State), mold opening (step S14), spacer extraction (step S16), and high-pressure mold clamping (step S18). Thereafter, the plate 354 is advanced through the rod 386 of the thin hydraulic cylinder 384 (step S30), the cavity is compressed (state shown in FIG. 12B), the mold is opened after cooling (step S22), and the molding is performed. finish. The effect of this example is the same as that of Example 5 described above.

  Next, Embodiment 7 of the present invention will be described with reference to FIGS. FIG. 14A is a diagram showing the overall configuration of the injection molding apparatus of this embodiment, FIG. 14B is a diagram showing the operation of this embodiment, and FIG. 15 uses the injection molding apparatus of this embodiment. It is a flowchart which shows the shaping | molding process by the made IMP method. As shown in FIG. 14, the injection molding apparatus 400 of this embodiment includes a toggle arm extension mechanism 410 as a cavity compression mechanism independent of the mold clamping mechanism 310. The toggle arm extension mechanism 410 is provided between the link 314C and the moving plate 308, and between the link 314E and the moving plate 308, respectively. The link 314C side will be described. A claw 418 is formed on the end 316 of the link 314C, and the groove 416 on the side surface of the connecting member 414 attached to the fixed portion 412 on the back surface of the moving plate 308 The nail 418 is guided. Further, a hydraulic cylinder 422 is provided in the vicinity of the link end portion 316 via a bent connecting member 420, and the tip of the rod 424 of the hydraulic cylinder 422 is in contact with the fixing portion 412. The hydraulic cylinder 422 is connected to the control device 140.

  In this embodiment, the rod 424 of the hydraulic cylinder 422 of the toggle arm extension mechanism 410 is retracted and the high pressure mold clamping (step) is performed in the same manner as in the fifth embodiment with the connecting member 414 in contact with the link end 316. S10) and injection of the resin 90 (step S12) (state shown in FIG. 14A), mold opening (step S14), spacer extraction (step S16), and high-pressure mold clamping (step S18). Thereafter, when the rod 424 is advanced by driving the hydraulic cylinder 422 of the toggle arm extension mechanism 410 (step S40), the link end 316 is disconnected from the connecting member 414 in accordance with the advance of the rod 424, and the moving plate 308 is moved. The stroke is made in the direction of the arrow F14 by the stroke obtained by pulling out the spacer 64, and the cavity C is compressed (state shown in FIG. 14B). Then, after cooling, the mold is opened (step S22), and the molding is finished. The effect of this example is the same as that of Example 5 described above.

  Next, Embodiment 8 of the present invention will be described with reference to FIGS. FIG. 16A is a diagram showing the overall configuration of the injection molding apparatus of this embodiment, FIG. 16B is a plan view showing a moving plate, and FIG. 16C is a diagram showing the operation of this embodiment. . FIG. 17 is a flowchart showing a molding process by the IMP method using the injection molding apparatus of this embodiment. The injection molding apparatus 450 of the present embodiment has a structure in which a pair of moving plates 308A and 308B are provided between a pair of fixed plates 302 and 304. The moving plates 308A and 308B are fixed plates 302 and 304, respectively. It is slidable along a guide rod 306 provided therebetween. The distance between the moving plates 308A and 308B can be adjusted by the mold clamping mechanism 310.

  The guide rod 306 has a threaded portion 306A on the outer peripheral surface on the fixed plate 304 side. On the other hand, nuts 462 screwed into the threaded portions 306A of the guide rod 306 are supported at the four corners on the back surface of the moving plate 308B so as to be rotatable with respect to the back surface of the moving plate 308B. A gear portion 464 is formed on the outer peripheral surface of the nut 462, and a belt 468 is hung on the gear portions 464 of the four nuts 462. A gear 470 that meshes with the belt 468 is rotatably supported on the back surface of the moving plate 308B by a shaft 472 that passes through the moving plate 308B. The shaft 472 is rotated by a motor 474 provided on the surface side of the moving plate 308B.

  By driving the motor 474, the nut 462 rotates through the shaft 472, the gear 470, the belt 468, and the gear portion 464. Here, since the nut 462 is rotatably supported with respect to the moving plate 308B, the moving plate 308B can slide in the direction of the arrow F16 along the threaded portion 306A of the guide rod 306 according to the rotation of the nut 462. Become. At this point, the distance between the moving plate 308B and the other moving plate 308A is kept constant by the mold clamping mechanism 310. At the same time, the moving plate 308B is moved in the direction of the arrow F16, and at the same time, the moving plate 308A and the moving plate 308A are moved. The supported movable mounting plate 60 also moves in the same direction. That is, in this embodiment, the clamp unit moving mechanism 460 is configured to compress the cavity C by causing the entire mold clamping mechanism 310 to stroke toward the fixed plate 302 side. In this embodiment, the hydraulic motor 320 of the mold clamping mechanism 310 is disposed between the moving plate 308B and the fixed plate 304, and is connected to the control device 140 together with the motor 474 to control the driving thereof. .

  In the present embodiment, from the state in which the moving plate 308A is moved back to the moving plate 308B side, as in the fifth embodiment, high-pressure clamping (step S10) and injection of the resin 90 (step S12) (FIG. 16A) ), Mold opening (step S14), spacer pull-out (step S16), and high-pressure mold clamping (step S18). Thereafter, the motor 474 of the clamp unit moving mechanism 460 is driven to move the entire clamp unit (moving plates 308A and 308B and the mold clamping mechanism 310) in the direction of arrow F16 (step S50), and the stroke obtained by pulling out the spacer 64. The cavity C is compressed by the amount (the state shown in FIG. 16B). Then, after cooling, the mold is opened (step S22), and the molding is finished. The effect of this example is the same as that of Example 5 described above.

  Next, Embodiment 9 of the present invention will be described with reference to FIG. 18A is a diagram showing the overall configuration of the injection molding apparatus of the present embodiment, FIG. 18B is a plan view of the movable side plate, and FIG. 18C is a diagram showing the operation of the ninth embodiment. is there. In the injection molding apparatus 500 of the present embodiment, the movable plate 354 is slidable along the guide pins 356 erected on the plate 382 fixed on the moving plate 308 as in the sixth embodiment. It is supported. A large-diameter screw member 502 is supported on the fixed plate 382 so as to be rotatable with respect to the plate 382. On the other hand, a large-diameter nut 504 is rotatably attached to the back surface of the movable plate 354. A gear portion 506 is formed on the outer peripheral surface of the nut 504. The plate 354 is provided with a motor 510, and a belt 508 is hung on the gear 512 and the gear portion 506 provided at the tip of the output shaft of the motor 510. Therefore, when the nut 504 is rotated through the gear 512, the belt 508, and the gear portion 506 by driving the motor 510, the screw member 502 that meshes with the nut 504 is fixed to the plate 382. It will slide along the pin 356. The motor 510 is connected to the control device 140 together with the hydraulic motor 320.

  In this embodiment, with the movable plate 354 retracted toward the moving plate 308, high pressure clamping (step S10 in FIG. 13) and injection of the resin 90 (step S12) are performed as in the sixth embodiment. (State of FIG. 18A), mold opening (step S14), spacer pull-out (step S16), and high-pressure clamping (step S18). Thereafter, the plate is moved forward by driving the motor 510 to compress the cavity (corresponding to step S30 in the sixth embodiment) (state shown in FIG. 18C), and after cooling, the mold is opened (step S22). Finish molding. The effect of this example is the same as that of Example 5 described above.

  Next, Embodiment 10 of the present invention will be described with reference to FIG. The present embodiment is an example in which a direct pressure type clamping mechanism using hydraulic pressure is used as a cavity compression mechanism, similar to the first to fourth embodiments described above, and is a structure suitable for molding a cylindrical product. It has become. FIG. 19A is an external perspective view showing the shape of a molded product molded by the injection molding apparatus of this example, FIG. 19B-1 is a diagram showing a compression portion according to a comparative example, and FIG. ) Is a diagram showing a compression portion according to the present embodiment, and FIGS. 19C to 19E are cross-sectional views showing a main part and a molding process of the injection molding apparatus of the present embodiment. As shown in FIG. 19 (A), a molded product 540 formed according to the present embodiment has a sprue runner 540B connected to one end surface side of a substantially cylindrical main body portion 540A via a connecting portion 540D. A resin reservoir 540C is connected to the end surface side of the resin via a connecting portion 540E. The sprue runner 540B and the resin reservoir 540C are separated from the mold of the injection molding apparatus 520 and then separated by the connecting portions 540D and 540E, and only the main body portion 540A is used as a product.

  When compressing a substantially cylindrical body such as the main body 540A, conventionally, as indicated by an arrow F19a in FIG. 19 (B-1), the movable stroke direction and the axial direction of the cylindrical shape are matched, There was no method other than compressing from one end face side of the cylindrical shape. On the other hand, as shown in FIG. 19 (B-2), in this example, even when the axial direction of the cylindrical shape is set to a direction substantially orthogonal to the movable stroke direction, one end surface of the cylindrical shape The object of the IMP method for suppressing sink marks and voids is achieved by performing compression through a resin reservoir provided on the side.

  The injection molding apparatus 520 of the present embodiment is basically the same as that of the first embodiment in the structure of the fixed side, but the sprue bush 56 penetrating the fixed side mounting plate 52 and the fixed mold 54 is more than the center. It is provided at a position near the end. On the other hand, the movable mold 522 has a substantially cylindrical molding hole 522A corresponding to the main body 540A of the molded product 540, a molding hole 522B corresponding to a part of the sprue runner 540B, and a portion corresponding to the resin reservoir 540C. The molding holes 522A and 522B are connected by a branch recess 522D, and the molding holes 522A and 522C are connected by a branch recess 522E. The sprue bushing 56 is connected to the forming hole 522B. Further, the forming hole 522C is formed so as to penetrate the movable mold 522 along the stroke direction of the movable mold 522, and a part of the slide core 536 is accommodated. One end side of the slide core 536 compresses the resin in the molding hole 522C, and the other end side passes through plates 528 and 530, which will be described later, and is seated on the movable side template 60 via the flange portion 538. Yes. As shown in FIG. 19 (E), a protruding rod 92 similar to that of the first embodiment passes through the movable side template 60 (not shown in FIGS. 19 (C) and 19 (D)). Further, a pressure sensor 80 is provided on the distal end side of the slide core 536, and the pressure sensor 80 is connected to the control device 140.

  One end of a leg portion 524 having a substantially L-shaped cross section is fixed to the rear end surface of the movable mold 522, and a hydraulic motor 712 is interposed between the other end of the leg portion 524 and the movable side mounting plate 60. A pullable spacer 64 is provided. Further, plates 528 and 530 that can be moved back and forth between the inner bottom surface 526 of the leg portion 174 and the movable mold 522 are provided in the inner portion surrounded by the leg portion 174 having a substantially L-shaped cross section. One plate 528 is formed with an opening 528A in which the flange 538 of the slide core 536 can be accommodated, and the slide core 536 can be inserted into the other plate 530, and the flange 538 cannot be penetrated. An opening 530A having a size is formed. One end of a plurality of (two in the illustrated example) protruding pins 532 is fixed to the plate 530. The protruding pin 532 passes through the movable mold 522 in the stroke direction and reaches the forming hole 522A. Further, a plurality of springs 534 are provided between the plate 530 and the movable mold 522. The spring 534 urges the plates 528 and 530 toward the movable mounting plate 60 side.

  In the present embodiment, after filling the molding holes 522A, 522B, and 522C shown in FIG. 19C with the resin 90, the mold clamping pressure by the mold clamping mechanism 176 is once released, and the hydraulic motor 172 is driven to drive the spacer 64. By extracting all from between the leg portion 524 and the movable side mounting plate 60, a space for moving the movable side mounting plate 60 in the direction of the arrow F19 is obtained by an amount corresponding to the thickness of the spacer 64. Here, when pressure is applied again by the mold clamping mechanism 176, the slide core 536 is formed into the molding hole 522C via the movable side mounting plate 60 and the flange portion 538 by the amount corresponding to the compression stroke formed by pulling out the spacer 64. The inside is slid in the direction of arrow F19a, and the resin 90 in the molding hole 522C is compressed as shown in FIG. Then, it becomes possible to compress the resin 90 in the substantially cylindrical molding hole 522A connected through the branch recess 522E in a direction (arrow F19b direction) orthogonal to the stroke direction of the movable mold 522. A substantially cylindrical shaped article 540 with reduced voids is obtained.

  When the resin is cooled and solidified, the mold is opened as shown in FIG. 19E, and the protruding part 92 pushes the plate 528 together with the flange 538 of the slide core 536 in the direction of the arrow F19. Mold is released. Also in the present embodiment, the control of the pressure in the mold at the time of the cavity volume compression (resin pool compression) by the mold clamping mechanism 176 is the same as in the first embodiment. In this embodiment, the direct pressure type clamping mechanism 176 is used as the cavity compression mechanism. However, another cavity compression mechanism that is used in addition to the toggle mechanism shown in the above-described embodiments 5 to 9 is used. Also good.

  Next, Embodiment 11 of the present invention will be described with reference to FIG. In each of the first to tenth embodiments described above, a configuration is adopted in which a compression stroke for compressing the cavity volume is secured by pulling out the spacer to the outside of the mold. This is an example in which 20A to 20C are cross-sectional views showing the main part and the molding process of the injection molding apparatus of this example. The injection molding apparatus 550 of the present embodiment is basically the same as that of the first embodiment, but the sprue bush 56 is provided at a position shifted from the center. On the other hand, the movable die 552 is provided with a molding hole 554 penetrating in the stroke direction of the movable die 552, and a part of the slide core 560 is accommodated in the molding hole 554, and the end surface of the slide core 560 is accommodated. And a cavity C is formed between the fixed mold 54 and the fixed mold 54. Another forming hole 556 corresponding to a sprue runner is connected to the forming hole 554 via a branch recess 555, and the sprue bush 56 is connected to the forming hole 556.

  One end of the slide core 560 is accommodated in the molding hole 554 to compress the resin 90 in the cavity C, and the other end can be directly seated on the movable side mounting plate 60. A groove 564 is provided at an appropriate position of the slide core 560, and a pin 566 provided at an appropriate position of the movable mold 552 is slidable in the groove 564. These grooves 564 and pins 566 constitute a retraction prevention mechanism 562 for preventing the slide core 560 from retreating toward the movable side mold plate 60 when the mold clamping by the mold clamping mechanism 176 is released. Further, a pressure sensor 80 is provided on the distal end side of the slide core 560, and the pressure sensor 80 is connected to the control device 140.

  Further, one end of a leg portion 553 is fixed to the rear end surface of the movable mold 552. The other end of the leg portion 553 is not fixed to the movable mounting plate 60, and the other end is in contact with the movable mounting plate 60 in the mold clamping state shown in FIG. Is set. Between the movable mold 552 and the movable side mounting plate 60, a plurality of springs for preventing the parting of the fixed mold 54 and the movable mold 552 from opening when the movable side mounting plate 60 is retracted after clamping. 558 is provided.

  In addition, between the movable mold 552 and the movable side mounting plate 60, along the main surface of the movable mold mounting plate 60 in a direction substantially orthogonal to the stroke direction (arrow F20a, F20b direction) of the movable mold 552. A slidable stepped spacer 570 is disposed. The spacer 570 can be inserted and removed between the movable side mounting plate 60 and the rear end of the slide core 560 by driving of a hydraulic motor 172. Furthermore, in this embodiment, a guide pin 580 that penetrates the movable mold 552 and the leg 553 in the stroke direction of the movable mold 552 is provided. The guide pin 580 has a double structure of an outer cylinder 580A and an inner cylinder 580B, one end of the outer cylinder 580A is fixed to the movable side mounting plate 60, and one end of the inner cylinder 580B is a recess provided in the movable mold 552. 582 is fixed. Then, the overlapping portion of the outer cylinder 580A and the inner cylinder 580B slides in the stroke direction so that it can expand and contract as a whole, and is configured to guide the advancement and retraction of the movable mounting plate 60 with respect to the leg portion 553.

  In this embodiment, when the resin 90 is filled into the cavity C shown in FIG. 20A, the spacer 570 is pulled out from between the movable mounting plate 60 and the slide core 560. Then, after the filling is completed, the mold clamping by the mold clamping mechanism 176 is once released and the movable side mounting plate 60 is moved backward in the direction of the arrow F20a. At this time, the sliding core 560 is moved backward by following the movable mounting plate 60 by the retraction preventing mechanism 562 without opening the parting surfaces of the movable mold 552 and the fixed mold 54 by the urging force of the spring 558. There is nothing to do. In this state, as shown in FIG. 20B, when the spacer 570 is moved inward of the mold by the drive of the hydraulic motor 172 and the flat portion is inserted between the movable side mounting plate 60 and the slide core 560. As shown in FIG. 20B, a compression stroke S5 for compressing the cavity volume is formed between the movable side mounting plate 60 and the leg portion 554.

  Accordingly, when the spacer 570 is inserted between the movable side mounting plate 60 and the slide core 560 and the movable side mounting plate 60 is moved in the direction of the arrow F20b by the mold clamping mechanism 176 as shown in FIG. The resin 90 in the cavity C is compressed by the slide core 560 by the distance corresponding to the compression stroke S5. Also in the present embodiment, the control of the pressure inside the mold when the cavity volume is compressed by the mold clamping mechanism 176 is the same as in the first embodiment. In this embodiment, the direct pressure type clamping mechanism 176 is used as the cavity compression mechanism. However, another cavity compression mechanism that is used in addition to the toggle mechanism shown in the above-described embodiments 5 to 9 is used. Also good.

  In addition, this invention is not limited to the Example mentioned above, A various change can be added in the range which does not deviate from the summary of this invention. For example, in the first embodiment, the portion of the fixed die 54 that faces the molding hole 68 of the movable die 66 is flat, but a corresponding molding uneven portion can be formed according to the shape of the product. Similarly, the surface of the slide core 74 facing the cavity C can also be formed with an uneven portion in accordance with the required shape of the product. The same applies to the other embodiments. In addition, the shape of the spacer 64 shown in the above embodiment is an example, and the contact surface of the leg portion 62A and the spacer 64A is inclined as in the modification shown in FIG. It is good also as a rust shape where the inner side is thinner than the outer side. When the spacer 64 having a rectangular cross section is used, pressure is applied after pulling out the spacer 64 at once, as in the above-described embodiment. The same effect as in the first embodiment can be obtained by extracting and applying pressure, and then quickly extracting the rest and applying pressure quickly. If the spacer 64A having the inclination is used, the compression stroke amount can be continuously changed in accordance with the drawing amount of the spacer 64A. In addition, by providing the spacer with two or more steps, the compression stroke amount is stepwise according to the amount of extraction (in the case of Examples 1 to 10) or the amount of insertion (in the case of Example 11) of the spacer. You may make it adjust.

  According to the present invention, when compressing the resin injected into the cavity formed between the fixed mold and the movable mold, the cavity internal pressure (or mold internal pressure) is detected by the pressure sensor, and based on the detection result, By performing compression control (control of compression pressure, compression speed, etc.) along the thermal shrinkage of the injected resin, the molding cycle is shortened, the internal stress of the product is reduced, the load on the mold is reduced, the product Therefore, it is possible to improve the finish and deformation of the resin, so that it can be used for injection molding. In particular, it is suitable for injection compression molding in which compression is performed after resin injection.

50: Injection molding apparatus 51: Mold 52: Fixed side mounting plate 54: Fixed type 56: Sprue bush 58: Cooling hole 60: Movable side mounting plate 62, 62A: Legs 64, 64A: Spacers 66, 66A: Movable type 68: Molding hole 70: Slide base 72A: First plate 72B: Second plate 74: Slide core 76: Spring 78: Cooling hole 80: Pressure sensor 82: Hydraulic cylinder 84: Rod 90: Resin 92: Extrusion rod 94: Hydraulic pressure Cylinder 100: Injection device 102: Cylinder 104: Hopper 106: Injection mechanism 108: Nozzle 110: Clamping mechanism 112: Hydraulic cylinder 114: Piston 116: Rod 118, 120: Oil chamber 122, 124: Inlet / outlet 130: Hydraulic pump 132: Timer 140: Control device 142: Clamping mechanism 150: Injection molding equipment Position 152: Leg 152A: Tip 152B: Rear end 160: Slide core 162: Inner core 162A, 162B, 164A, 164B: End 164: Outer core 166: First slide base 168: Compression stroke amount adjusting screw 170 : Second slide base 172: Hydraulic motor 174: Screw shaft 176: Clamping mechanism 180: Product 182: Surface solidified layer 184: Convex part 186: Thin part 188: Biting part 190: Product 192: Main body part 194: Projection part 196: Connecting portion 200: Injection molding device 202: Branch recess 204: Leg portion 206: First slide core 206A, 206B: End portion 208: Slide base 210: Compression stroke amount adjusting screw 212: Molding holes 214A, 214B: Small diameter portion 216: Large diameter portion 218: Edge portion 220: Second slide core 220A, 220B: End 222: collar portion 224: spring 300: injection molding device 302, 304: fixed plate 306: guide rod 306A: screw portion 308, 308A, 308B: moving plate 310: mold clamping mechanism 312: rods 314A to 314F: link 316: end Unit 320: hydraulic motor 350: injection molding device 352: compression unit 354: plate 356: guide pin 358: spring 360: movable unit 362: fixed unit 360A, 362A: taper 364: rod 366: hydraulic motor 380: injection molding device 382 : Plate 384: Thin hydraulic cylinder 386: Rod 400: Injection molding device 410: Toggle arm extension mechanism 412: Fixing part 414: Connecting member 416: Groove 418: Claw 420: Connecting member 422: Hydraulic cylinder 424: Rod 450: Shooting Molding device 460: Clamp unit moving mechanism 462: Nut 464: Gear portion 468: Belt 470: Gear 472: Shaft 474: Motor 480: Nut 500: Injection molding device 502: Screw member 504: Nut 506: Gear portion 508: Belt 510 : Motor 512: Gear 520: Injection molding device 522: Movable molds 522A to 522C: Molding holes 522D and 522E: Branch recess 524: Leg 526: Inner bottom surface 528 and 530: Plates 528A and 530A: Opening 532: Extrusion pin 534: Spring 536: slide core 538: collar portion 540: molded product 540A: main body 540B: sprue runner 540C: resin reservoir 540D, 540E: connecting portion 550: injection molding device 552: movable mold 553: leg 554, 556: molding Hole 555: Branch recess 558: Splice 560: Slide core 562: Retraction prevention mechanism 564: Groove 566: Pin 570: Spacer 580: Guide pin 580A: Outer cylinder 580B: Inner cylinder 582: Recess 600: Injection molding device 602: Fixed mold 604: Sprue bush 606: Nozzle 608, 608 ': movable mold 608A to 608C: division piece 610: pressure sensor 612: resin 614: burr 616: heat insulation layer 620: product 650, 650A, 650B: injection compression molding apparatus 700: injection molding apparatus 702: fixed side mounting Plate 704: Fixed mold 706: Sprue bush 708: Nozzle 710: Movable mounting plate 712: Movable mold 714: Leg 716: Spacer 718: Molding hole 720: Slide core 722: Slide base 724: Pressure sensor 730: Resin 732: Burr C: Cavity I: Gap S1, S3: Spacing S2, 4: Thickness T1~T6: the passage V1~V4: valve

Claims (18)

A movable mold supported by the movable mold mounting plate, and a mold in which a cavity into which molten resin is injected and filled is formed when the end surface of the fixed mold supported by the fixed mounting plate is brought into contact;
An injection mechanism for injecting and filling molten resin into the cavity;
A mold clamping mechanism that strokes the movable side mounting plate with respect to the fixed side mounting plate to open and close the mold, and at the time of injection filling of the molten resin by the injection mechanism, a mold clamping mechanism for high pressure clamping
One or more formed on the movable mold in the stroke direction, opening at an end face facing the fixed mold, and forming at least a part of the cavity when the fixed mold is brought into contact with the end face Molding holes,
A part of the molding hole is accommodated, and a slide core that can slide along the molding hole;
Due to the movement of the spacer disposed between the movable side mounting plate and the movable mold, the slide core slides in the molding hole in the direction of compressing the cavity volume while the mold is closed after clamping. Compression stroke forming means for ensuring a compression stroke for,
A cavity compression mechanism that compresses the volume of the cavity by sliding the slide core along the molding hole while keeping the mold closed according to the stroke amount obtained by the compression stroke forming means;
A pressure sensor for detecting the internal pressure of the cavity;
Control means for adjusting a compression pressure and a compression speed by the cavity compression mechanism based on a detection result of the pressure sensor, and controlling a change in the cavity pressure with time;
An injection molding apparatus comprising: While providing a temperature adjusting means for adjusting the temperature of the mold,
The control means includes
2. The injection molding apparatus according to claim 1, wherein a change with time of the internal pressure of the cavity is controlled by controlling the temperature adjusting means together with the cavity compression mechanism based on a detection result of the pressure sensor. The compression stroke forming means comprises:
A leg portion disposed between the movable side mounting plate and the movable mold, one end of which is fixed to one surface of the movable side mounting plate and the movable mold;
Between the other end where the leg portion is not fixed and the movable side mounting plate, or between the other end where the leg portion is not fixed and the movable mold, it is slidably arranged in a direction substantially perpendicular to the stroke direction. A spacer;
A slide mechanism for sliding the spacer;
With
3. The injection molding apparatus according to claim 1, wherein after the mold is clamped, the compression stroke is ensured by moving the spacer toward the outside of the mold.   4. The injection molding apparatus according to claim 3, wherein the amount of the compression stroke can be adjusted according to the amount of movement of the spacer.   The contact surface between the spacer and the leg portion is inclined with respect to the fixed-side mounting plate, and the compression stroke amount can be continuously changed according to the movement amount of the spacer. The injection molding apparatus according to claim 4. The compression stroke forming means comprises:
A leg portion disposed between the movable side mounting plate and the movable mold, one end fixed to the movable mold, and the other end abuttable with the movable side mounting plate;
It is arranged so as to be slidable along the main surface of the movable mounting plate in a direction substantially perpendicular to the stroke direction, and can be inserted and extracted between the movable mounting plate and the slide core. A spacer;
A slide mechanism for sliding the spacer;
With
After the mold is clamped, the compression stroke is secured between the movable side mounting plate and the leg by inserting the spacer between the movable side mounting plate and the slide core. Item 3. The injection molding apparatus according to Item 1 or 2.   The injection molding apparatus according to claim 1, wherein the mold clamping mechanism also serves as the cavity compression mechanism. One end of the slide core is arranged so as to be seated directly or indirectly on the movable side mounting plate,
The injection molding apparatus according to claim 7, wherein the volume of the cavity is compressed by sliding the slide core together with the movable attachment plate by the mold clamping mechanism. When the mold clamping mechanism is a mechanism that strokes a moving plate that supports the movable side mounting plate with respect to the fixed plate that supports the fixed side mounting plate by using a toggle mechanism,
The cavity compression mechanism is
Support means for supporting the movable side mounting plate slidably in the stroke direction with respect to the moving plate;
Adjusting means for adjusting the distance between the movable plate and the movable side mounting plate;
The injection molding apparatus according to claim 1, comprising: When the mold clamping mechanism is a mechanism that strokes a moving plate that supports the movable side mounting plate with respect to the fixed plate that supports the fixed side mounting plate by using a toggle mechanism,
The cavity compression mechanism is
A connecting means for connecting a connecting portion of the toggle mechanism and the movable plate so that the length thereof can be adjusted or separated;
A moving plate slide mechanism for sliding the moving plate in the stroke direction;
The injection molding apparatus according to claim 1, comprising: When the mold clamping mechanism is a mechanism that strokes a moving plate that supports the movable side mounting plate with respect to the fixed plate that supports the fixed side mounting plate by using a toggle mechanism,
The cavity compression mechanism is
The injection molding apparatus according to any one of claims 1 to 6, wherein the entire mold clamping mechanism is caused to stroke beyond an upper limit of a stroke by the mold clamping mechanism. When the slide core accommodated in one molding hole is divided into a plurality of parts, or when the slide core is accommodated in each of the plurality of molding holes,
A compression timing adjusting means for adjusting the timing of the compression start so that the timing of cavity compression by the plurality of slide cores is different;
The injection molding apparatus according to claim 1, wherein the injection molding apparatus is provided. A mold that is divided and formed into a movable mold and a fixed mold, and a cavity in which molten resin is injected and filled on the divided surface;
An injection mechanism for injecting and filling molten resin into the cavity;
A mold clamping mechanism that strokes the movable mold with respect to the fixed mold and opens and closes the mold;
A pressure sensor for detecting the internal pressure of the cavity;
Control means for controlling the change over time of the internal pressure of the cavity by adjusting the compression pressure and compression speed by the mold clamping mechanism based on the detection result of the pressure sensor;
An injection molding apparatus comprising: While providing a temperature adjusting means for adjusting the temperature of the mold,
The control means includes
14. The injection molding apparatus according to claim 13, wherein a change with time in the cavity internal pressure is controlled by controlling the temperature adjusting means together with the mold clamping mechanism based on a detection result of the pressure sensor. An injection molding method in which molten resin is injected and filled into a cavity formed on a dividing surface of a movable mold and a fixed mold, compressed, and cooled and solidified.
An injection molding method characterized in that an internal pressure of the cavity is detected by a pressure sensor, and compression control is performed along the thermal contraction of the injection-filled resin based on the detection result. An injection molding method using the injection molding apparatus according to any one of claims 1 to 12,
After the injection filling of the molten resin by the injection mechanism, when the compression stroke forming means obtains a compression stroke and compresses the cavity,
The said control means controls the compression by the said cavity compression mechanism according to the shrinkage | contraction of the said injection-filled resin based on the detection result of the said pressure sensor, The injection molding method characterized by the above-mentioned. An injection molding method using the injection molding apparatus according to claim 13 or 14,
After injection filling of molten resin by the injection mechanism,
The said control means controls the compression by the said mold clamping mechanism according to shrinkage | contraction of the said injection-filled resin based on the detection result of the said pressure sensor, The injection molding method characterized by the above-mentioned.   The said control means controls a compression pressure and a compression speed so that the internal pressure of the cavity in a compression process may not exceed the pressure at the time of an injection pressure peak, It is any one of Claims 15-17 characterized by the above-mentioned. Injection molding method.

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