JP2005305871A - Plastic injection molding mold apparatus, method for manufacturing plastic molded article, plastic molded article, and a mold clamping and fixing tool for plastic injection molding mold apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic injection molding mold apparatus capable of positioning and fixing of a core plate without depending on a frictional force and preventing the core plate and the cavity plate from being broken, a method for manufacturing a plastic molded article using a mold for injection molding of a plastic, a plastic injection-molded article obtained from the plastic injection molding mold apparatus, and a clamping and fixing tool for the plastic injection molding mold apparatus. <P>SOLUTION: The plastic injection molding mold apparatus is characterized by that a mold clamping bush is buried by exposing its opening part on the lower face of the cavity plate, a mold clamping pin projecting from the upper face of the core plate and fitting to the mold clamping bush is planted, the projected part of the mold clamping pin is formed into a tapered column-like shape with a decreasing diameter upward, and the mold clamping bush has a tapered hole with a decreased diameter upward by an approximately equal angle of taper to the tapered shape of the projected part of the mold clamping pin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention can fix the position of the core plate without depending on the frictional force, can reduce the moving speed of the core plate during the mold clamping operation, facilitates the detection of foreign matter attached to the core plate, Plastic injection mold apparatus capable of preventing breakage of plate and cavity plate and obtaining desired mold clamping force, method for producing plastic molded product using plastic injection mold apparatus, plastic The present invention relates to a plastic injection molded product obtained from an injection mold apparatus and a mold clamping fixture of the plastic injection mold apparatus.

FIG. 12 shows a conventional plastic injection mold apparatus (100).
The conventional mold apparatus (100) is connected to the top plate (102) to which the injection nozzle (101) for injecting molten plastic is connected, and is connected to the top plate (102) and molds one surface of the plastic molded product. A cavity plate (103), a core plate (104) connected to the cavity plate (103), and a bottom plate (115) connected to the core plate (104).
A cavity (105) imitating a molded product is formed between the cavity plate (103) and the core plate (104). Further, a molten plastic supply path (106) connecting the molten plastic injection hole of the injection nozzle (101) and the cavity (105) is formed inside the top plate (102) and the cavity plate (103). The molten plastic injected from the injection nozzle (101) is supplied into the cavity (105) through the supply path (106), and a plastic molded product imitating the cavity (105) is formed.
As described above, since the molten plastic is injected toward the cavity (105) formed between the cavity plate (103) and the core plate (104), a cylindrical protrusion (107) is formed on the core plate (104). ) Is formed, and the cavity plate (103) is formed with a fitting hole (108) that fits with the protrusion (107), and the outer periphery of the protrusion (107) and the inner periphery of the fitting hole (108) The core plate (104) is fixed so as not to separate from the cavity plate (103) while injecting the molten plastic.

FIG. 13 shows a step of taking out a molded product formed from the mold apparatus (100) shown in FIG. Fig.13 (a) shows the state of the metal mold | die apparatus (100) when taking out a molded article, FIG.13 (b) shows the molded article taken out.
When the molded product is removed from the mold apparatus (100), the core plate (104) is retracted away from the cavity plate (103). At this time, since the molded product formed in the cavity (105) is connected to the plastic resin in the supply path (106), it remains on the cavity plate side. Thereafter, the molded product on the cavity plate (106) side is taken out from the mold apparatus (100).
Since the molded product on the cavity plate (106) side is connected to the plastic resin in the supply path (106), the plastic resin in the supply path (106) protrudes and is connected to the extracted molded product. . Therefore, after the molded product is taken out from the mold apparatus (100), it is necessary to remove the protruding portion from the molded product, resulting in an increase in the number of steps for processing the molded product.

FIG. 14 shows another embodiment of the mold apparatus. In the mold apparatus (200) shown in FIG. 14, the molded product taken out of the mold apparatus (100) shown in FIGS. 12 and 13 is accompanied by the plastic resin in the supply flow path (106). This is a form that eliminates the problem of forming protrusions on the product.
The mold apparatus (200) shown in FIG. 14 is similar to the mold apparatus (100) shown in FIGS. 12 and 13, and the top plate (202) to which the injection nozzle (201) for injecting molten plastic is connected. ), A cavity plate (203) connected to the top plate (202) and forming one surface of the plastic molded product, a core plate (204) connected to the cavity plate (203), and a core plate (204) And a bottom plate (215) connected to the base plate. The mold apparatus (200) further includes an attachment plate (209) between the top plate (202) and the cavity plate (203). As will be described later, the cavity plate (203) is attached to the attachment plate (209). Can be moved up and down. A pair of spacers (210) are disposed on the left and right sides of the lower surface of the core plate (204) to form a space between the bottom plate (215) and the cavity plate (204). An eject plate (211) is disposed in this space, and an extrusion rod (212) extends from the eject plate (211) toward the core plate (204).
Similar to the mold apparatus (100) shown in FIGS. 12 and 13, a cavity (205) imitating a molded product is formed between the cavity plate (203) and the core plate (204). . Also, a molten plastic supply path (206) connecting the molten plastic injection hole of the injection nozzle (201) and the cavity (205) is formed inside the top plate (202), the attachment plate (209), and the cavity plate (203). ing. The molten plastic injected from the injection nozzle (201) is supplied into the cavity (205) through the supply path (206), and a plastic molded article imitating the cavity (205) is formed.
Similar to the mold apparatus (100) shown in FIGS. 12 and 13, since the molten plastic is injected toward the cavity (205) formed between the cavity plate (203) and the core plate (204), The core plate (204) is provided with a cylindrical protrusion (207), and the cavity plate (203) is formed with a fitting hole (208) for fitting with the protrusion (207). ) The core plate (204) is fixed so as not to be separated from the cavity plate (203) while the molten plastic is being injected by the frictional force between the outer peripheral surface and the inner peripheral surface of the fitting hole (208).

15 to 17 are views showing a molded product taking-out process of the mold apparatus (200) shown in FIG.
In the molded product removal step, first, as shown in FIG. 15, the cavity plate (203) moves away from the attached plate (209). Thereby, the plastic resin in the supply path (206) is separated from the molded product imitated in the cavity (205). As a result, the molded product obtained from the mold apparatus (200) has a shape that does not have a protruding portion made of plastic resin that remains in the supply path, and the process of removing the protruding portion is not necessary.
As shown in FIG. 16, the core plate (204) further moves away from the cavity plate (203). At this time, since the molded product formed in the cavity (205) is separated from the plastic resin in the supply path (206), it moves downward together with the core plate (204) disposed below the cavity plate (203). To do.
As shown in FIG. 17, thereafter, the eject plate (211) moves upward, and the extruded rod (212) extending from the eject plate (211) pushes the molded product on the core plate (204) upward. Thereby, a molded product is extruded from a metal mold | die apparatus (200).
The molded product taken out from the mold apparatus (200) has a shape imitating the shape of the cavity (205) as it is without accompanying plastic resin in the supply path (206).

When the molten plastic is injected from the injection nozzle (101, 201) with the above-described mold apparatus (100, 200), the position of the core plate (104, 204) with respect to the cavity plate (103, 203) is fixed, In order to perform mold clamping, the projecting portions (107, 207) are provided on the core plates (104, 204), and the cavity plate (103, 203) is fitted with the fitting holes (107, 207). 108, 208). Then, the protrusions (107, 207) and the fitting holes (108, 208) are fitted, and the frictional force between the peripheral surfaces of the protrusions (107, 207) and the fitting holes (108, 208) is The cavity plate (103, 203) and the core plate (104, 204) were connected and fixed.
Depending on the shape of the cavities (105, 205), it is difficult for molten plastic to reach every corner of the cavities (105, 205). In this case, the injection pressure of the injected molten plastic is set to be very high. In order to perform reliable mold clamping even with such a high injection pressure, a very high frictional force is required between the peripheral surfaces of the protrusions (107, 207) and the inner peripheral surfaces of the fitting holes (108, 208). The fitting tolerance between the projections (107, 207) and the fitting holes (108, 208) needs to be designed to be very small.

FIG. 18 shows a state before mold clamping of the mold apparatus (200) shown in FIGS.
Before the mold clamping, the mold apparatus (200) is provided with a top plate (202), an attachment plate (209) and a cavity plate (203) adjacent to each other. In the lower part, a core plate (204), a spacer (210) and a bottom plate (215) are installed adjacent to each other. Then, the core plate (204), the spacer (210), and the bottom plate (215) move together to perform mold clamping.
In this step, in order to completely form the cavity (205) formed between the cavity plate (203) and the core plate (204), the entire length of the protrusion (207) is fitted into the fitting hole (208). It is necessary to When fitting into the fitting hole (208), the peripheral surface of the protrusion (207) will rub against the inner surface of the fitting hole (208) under a tight fitting relationship with the fitting hole (208).
14 to 17, the peripheral surface of the protrusion (207) rubs against the inner surface of the fitting hole (208) even when the core plate (204) is separated from the cavity plate (203). It will meet.
When the mold clamping operation and the molded product take-out operation are repeated, the protrusion (207) and the inner surface of the fitting hole (208) are rubbed and worn, whereby the protrusion (207) and the fitting hole (208 ) And the mating relationship will gradually loosen.

  In order to solve the above problems, Patent Documents 1 and 2 propose a mold apparatus including a cylindrical protrusion that can expand the outer diameter. According to the mold apparatus disclosed in Patent Documents 1 and 2, the protrusions (107, 207) and the fitting holes (108, 208) are expanded by enlarging the outer diameter of the cylindrical protrusions (107, 207). ) Can be tightly fitted.

JP-A-11-320635 Japanese Utility Model Publication No. 2-23393

By using the protrusions disclosed in Patent Documents 1 and 2, the problem of wear of the protrusions (107, 207) and the fitting holes (108, 208) can be solved to some extent. The disclosed method basically performs clamping by a frictional force between the peripheral surface of the protrusion and the fitting hole.
Therefore, in order to fit the full length of the projections (107, 207) into the fitting holes (108, 208) when the fitting holes (108, 208) are fitted, the core is resisted against this frictional force. It is necessary to move the plate (104, 204) upward, and during the clamping operation, the core plate (104, 204) and the portion disposed below the core plate (104, 204) are moved upward at high speed. Must move towards.

If foreign matter such as a part of the molded product has adhered to the surface of the core plate (104, 204) facing the cavity plate (103, 203) due to a defect in the molded product removal process, etc., without removing the foreign material. If the mold clamping process is performed, when the core plate (104, 204) and the cavity plate (103, 203) collide, the core plate (104, 204) and / or the cavity plate (103, 203) is large. You will be damaged. In particular, when foreign matter is attached to the protrusions (107, 207), the damage is extremely large.
In order to prevent such damage, when foreign matter is detected by means such as a sensor for detecting foreign matter, the mold clamping process is interrupted and the movement of the core plate (104, 204) is stopped. When (104, 204) is moving at a high speed as described above, it is very difficult to detect foreign matter. Furthermore, even if foreign matter can be detected, if the core plate (104, 204) is moving at a high speed, the braking distance until the core plate (104, 204) stops is increased, and the core plate ( 104, 204) and the core plate (104, 204) cannot be stopped before the cavity plate (103, 203) collides.

  Further, when the protrusions (107, 207) and the fitting holes (108, 208) are fitted at high speed, the peripheral surfaces of the protrusions (107, 207) and the inner surfaces of the fitting holes (108, 208) Wear is even more severe. For example, even if the diameter of the protrusions (107, 207) is enlarged and the wear is compensated by the structure of the protrusions disclosed in Patent Documents 1 and 2, the protrusions (107, 207) Therefore, it is necessary to frequently adjust the diameter of the steel sheet, and the work efficiency is reduced.

  The present invention has been made in view of the above circumstances, and can fix the position of the core plate regardless of the frictional force, and can reduce the moving speed of the core plate during the mold clamping operation. A plastic injection mold apparatus and a plastic injection mold that can easily detect foreign matter adhering to the core, prevent the core plate and the cavity plate from being damaged, and obtain a desired clamping force. It is an object of the present invention to provide a method for producing a plastic molded article using the above, a plastic injection molded article obtained from a plastic injection mold apparatus, and a mold clamping fixture for the plastic injection mold apparatus.

The invention according to claim 1 includes a cavity plate for molding one surface of the molded product and a core plate disposed below the cavity plate, and the molded product is simulated in a state where the cavity plate and the core plate are in contact with each other. A plastic injection mold apparatus in which a cavity is formed, wherein an injection nozzle for injecting a molten plastic resin is disposed above the cavity plate, and the cavity plate is injected from the injection nozzle. A supply path for supplying the molten plastic into the cavity is formed, and a bottom-end cylindrical clamping bush is embedded from the lower surface of the cavity plate with its opening exposed to the lower surface of the cavity plate, and the core plate A drive source that moves the core plate up and down is disposed below. On the upper surface of the core plate, a clamping pin that protrudes from the upper surface of the core plate and fits with the clamping bush is planted, and the protruding portion of the clamping pin has a tapered cylindrical shape that decreases in diameter upward. The plastic injection mold apparatus is characterized in that the mold clamping bush is formed with a tapered hole having a taper angle substantially equal to a taper shape of the projecting portion of the mold clamping pin and decreasing in diameter upward.
According to a second aspect of the present invention, a stripper plate is disposed between the cavity plate and the injection nozzle, the cavity plate can be moved up and down below the stripper plate, and the cross-sectional area of the supply path is downward. 2. The plastic injection mold apparatus according to claim 1, wherein the plastic injection mold apparatus is formed so as to gradually become smaller.
According to a third aspect of the present invention, the drive source raises the core plate at a predetermined speed until the tip of the clamping pin passes through the opening surface of the clamping bush, and the tip of the clamping pin is 3. The plastic injection mold apparatus according to claim 1, wherein the core plate is accelerated and raised after passing through the bush opening surface.
According to a fourth aspect of the present invention, the plastic injection mold apparatus further includes an impact force supply source that applies an impact force to the core plate, and the drive source has an outer peripheral surface of the mold clamping pin in the mold clamping bush. The core plate is raised at a predetermined speed until it abuts against the wall surface. After the outer peripheral surface of the clamping pin abuts against the inner wall surface of the clamping bush, the impact force supply source is directed upward toward the core plate. 3. The plastic injection mold apparatus according to claim 1, wherein an impact force is applied.

According to a fifth aspect of the present invention, the core plate for molding one surface of the molded product is raised and brought into contact with the cavity plate disposed above the core plate, and the molded product is interposed between the core plate and the cavity plate. Forming a cavity imitating the mold, injecting molten plastic into the cavity, molding the plastic into the shape of the cavity, lowering the core plate relative to the cavity plate, and molding A step of exposing the plastic and a step of taking out the molded plastic from the mold, and in the step of forming the cavity, a mold clamping pin that protrudes from the core plate and is tapered and formed upward. When the tip is embedded in the cavity plate and formed into a cylindrical shape with one end In addition, the core plate rises at a predetermined speed until it passes through the opening surface of the mold clamping bush having a taper hole that is formed with a taper angle substantially equal to that of the mold clamping pin, and the mold clamping pin After passing through the opening surface of the mold clamping bush, the plastic mold is produced at a speed higher than the predetermined speed.
According to a sixth aspect of the present invention, the core plate that molds one surface of the molded product is raised and brought into contact with the cavity plate disposed above the core plate, and the molded product is interposed between the core plate and the cavity plate. Forming a cavity imitating the mold, injecting molten plastic into the cavity, molding the plastic into the shape of the cavity, lowering the core plate relative to the cavity plate, and molding The outer periphery of the clamping pin is formed of a step of exposing the plastic and a step of taking out the molded plastic from the mold, and in the step of forming the cavity, the outer periphery of the clamping pin is formed so as to protrude from the core plate and taper upward. When the surface is embedded in the cavity plate and formed into a cylindrical shape with one end In addition, the core plate rises at a predetermined speed until it comes into contact with the inner wall surface of the mold clamping bush having a tapered hole that is formed thinly upward with a taper angle substantially equal to that of the mold clamping pin. Is a method of manufacturing a plastic molded product, wherein an impact force is applied upward to the core plate after contacting the inner wall surface of the mold clamping bush.
According to a seventh aspect of the present invention, after the step of molding a plastic molded product in the cavity, before the core plate is lowered, both the cavity plate and the core plate are disposed above the cavity plate. 7. The method for producing a plastic molded product according to claim 5, further comprising a step of lowering the molten plastic with respect to an injection nozzle that injects the plastic into the cavity.

  According to the eighth aspect of the present invention, the outer periphery of the clamping pin is formed in a taper shape so as to be narrowed upward, and is formed in a cylindrical shape having a bottom at one end and is narrowed toward the bottom at a taper angle substantially equal to that of the clamping pin. A fitting amount defined as an amount by which the die clamping pin is pushed into the die clamping bush from a state in which the inner wall surface of the die clamping bush having a tapered hole is in contact, and the die with respect to the fitting amount The relationship between the clamping pin and the fitting force between the clamping bushes is determined for a plurality of differently shaped clamping pins and clamping bushes, and the fitting amount is smaller than the allowable burr thickness for the plastic molded product. And selecting a clamping pin and a clamping bush capable of obtaining a fitting force that can counteract the injection pressure of the molten plastic from the relationship between the fitting amount and the fitting force. The selected clamping pin protrudes from the upper surface of the core plate according to the amount of fitting, the selected clamping bush is embedded in the cavity plate, and the core plate is brought into contact with the cavity plate. A cavity is formed between the core plate and the cavity plate, and a plastic melted from an injection nozzle disposed above the cavity plate is introduced into the cavity through a supply path formed inside the cavity plate. Injection, molding the plastic in the cavity, and lowering the cavity plate and the core plate together with the injection nozzle to separate the plastic resin staying in the supply path from the plastic resin in the cavity Plastic molding characterized by being obtained by It is.

According to a ninth aspect of the present invention, in the plastic injection mold, the cavity plate is disposed on a side where the molten plastic resin is injected and forms one surface of the plastic molded product, and the plastic molded product A mold clamping fixture that clamps and fixes between one surface of the core plate and the core plate, wherein the mold clamping fixture is embedded in the cavity plate, and an opening thereof is formed on the molding surface of the cavity plate. A mold-clamping bush having a substantially one-end bottomed cylindrical shape to be exposed; a mold-clamping pin which is implanted in the core plate and protrudes from a molding surface of the core plate and engages with the mold-clamping bush; The inner wall surface of the bush is formed in a tapered shape whose diameter decreases toward the bottom surface, and the clamping pin is a tapered shape of the inner wall surface of the clamping bush. In substantially the same taper angle as the taper angle of a clamping fixture, characterized in that to reduce the diameter toward the tip.
According to a tenth aspect of the present invention, a female screw portion is formed at the bottom of the clamping bush, and a bolt is screwed into the female screw portion through a through hole formed on the surface opposite to the molding surface of the cavity plate. The mold clamping fixture according to claim 9, wherein the mold clamping bush is movable in the cavity plate in an axial direction of the mold clamping bush.
The invention according to claim 11 is the mold clamping fixture according to claim 9 or 10, wherein a groove is formed on the outer peripheral surface of the mold clamping pin in the middle part of the mold clamping pin in the axial direction.

According to the first aspect of the present invention, since the shape of the protruding portion of the clamping pin and the taper hole of the clamping bush are substantially the same, when the clamping pin and the clamping bush are fitted, the entire outer periphery of the clamping pin Will simultaneously abut against the inner wall surface of the mold clamping bush, and these wall surfaces hardly rub against each other. Therefore, the mold clamping pin and the mold clamping bush are hardly worn, and a plastic injection mold apparatus having a long-life mold clamping fixture is obtained. Further, when the mold clamping pin is inserted into the mold clamping bush, since there is no resistance due to friction, the speed at which the core plate is raised can be reduced as compared with the prior art. Therefore, it becomes easy to detect foreign matters on the core plate, and the risk of damage to the core plate and the cavity plate can be reduced.
According to the second and seventh aspects of the present invention, since the cross-sectional area of the supply path is narrowed downward, the plastic resin in the supply path is separated from the cavity plate when the cavity plate moves downward, and the stripper plate Will stay on top. Thereby, the plastic resin in the supply path can be removed, and the flow of the resin into which the plastic resin flows in the supply path in the subsequent molding process is not hindered.
According to the third and fifth aspects of the present invention, the core plate can be moved at a low speed until the mold clamping pin passes through the mold clamping bush opening surface, and foreign matter adhering to the core plate or the mold clamping pin can be easily detected. Thus, the risk of breakage of the core plate and the cavity plate is reduced.
According to the fourth and sixth aspects of the present invention, the core plate can be slowed down over substantially the entire moving section, and foreign matter adhering to the core plate or the clamping pin can be detected more reliably. Become. Therefore, the risk of breakage of the core plate and the cavity plate can be further reduced.
According to the eighth aspect of the present invention, since the plastic resin in the supply path and the resin in the cavity are separated, the resin in the supply path does not accompany the molded product.
In addition, even if the force to push up the core plate is insufficient due to a defect in the mold clamping process, it is guaranteed that the burr thickness of the molded product to be molded is within the allowable range, and the quality is a certain level or higher. It is guaranteed that it is a molded product.
According to the ninth aspect of the present invention, even when the tip of the clamping pin reaches the end surface of the clamping bush, a gap is formed between the outer peripheral surface of the clamping pin tip and the inner periphery of the clamping bush. Therefore, no frictional force is generated between the mold clamping pin and the mold clamping bush, so that it is not necessary to move the core plate at a high speed, and the core plate can be moved at a lower speed than in the past. Therefore, even when a molded product adheres to the clamping pin, the attached molded product can be easily detected.
Also, when the tip of the clamping pin reaches the end of the clamping bush, no impact force is generated, and at the moment when the clamping pin is engaged with the clamping bush, the entire outer periphery of the clamping pin fitting part is clamped. Since it collides with the inner wall surface of the bush, internal stress generated in the clamping pin and clamping bush at the time of collision is alleviated, damage to the clamping fixture is reduced, and a longer life than the conventional clamping fixture can be obtained. It becomes possible.
According to the invention described in claim 10, since the position of the clamping bush becomes variable, the fitting amount between the clamping pin and the clamping bush can be adjusted, and the clamping force can be adjusted by increasing or decreasing the fitting amount. Become.
According to the eleventh aspect of the present invention, when the clamping pin is pressed against the inner peripheral surface of the clamping bush, the groove portion compressively deforms and brings about a spring action, so that the portion of the clamping pin at the tip is stronger than the groove portion. It can be pressed by force and higher clamping force can be obtained.

Hereinafter, embodiments of a plastic injection mold according to the present invention will be described with reference to the drawings. FIG. 1 is a view showing a state before clamping of a plastic injection mold according to the present invention.
The plastic injection mold apparatus (300) includes a top plate (302) connected to an injection nozzle (301) for injecting molten plastic. A stripper plate (309) is connected to the lower surface of the top plate (302). A cavity plate (303) is connected to the lower surface of the stripper plate (309).
A core plate (304) is arranged at a predetermined distance from the cavity plate (303). A pair of spacers (310) are disposed on the left and right ends of the lower surface of the cavity plate (304), and the lower surface of the spacer (310) is connected to the bottom plate (315).
As will be described later, the core plate (304) and the parts disposed below the core plate move upward in the mold clamping process, and the movement is a round bar-shaped guide bar (313) extending from the top plate (302). ) The stripper plate (309), the cavity plate (303), the core plate (304), and the spacer (310) are formed with guide holes through which the guide rod (313) passes. The lower end of the guide bar (313) is formed with a large-diameter head, and the upper surface of the head (318) is caught in the guide hole, thereby determining the lower limit position of the movement of the bottom plate (315). Yes.
A hydraulic cylinder (314) is disposed below the bottom plate (315). The hydraulic cylinder (314) pushes up the bottom plate (315) and the parts connected to the bottom plate (315) upward. In the example shown in FIG. 1, the hydraulic cylinder (314) is used, but other drive sources such as a motor may be used.
A mold clamping pin (307) is disposed on the core plate (304), and the tip of the mold clamping pin (307) protrudes vertically from the upper surface (340) of the core plate (304).
A mold clamping bush (308) that fits the mold clamping pin (307) is disposed at a position that coincides with the axis of the mold clamping pin (307). The mold clamping bush (308) is embedded in the cavity plate (303).

FIG. 2 shows an enlarged view of the clamping pin (307).
The mold clamping pin (307) is formed in a substantially round bar shape, and consists of three parts: a base end part (371), a middle part (372) and a taper part (373).
The clamping pin (307) is inserted from the lower surface of the core plate (304), and the lower surface of the core plate (304) and the lower surface of the base end portion (371) are flush with each other. The bottom surface of the base end portion (371) is in contact with the top surface of the spacer (310).
The middle part (372) extends upward from the base end part (371) and has a cylindrical shape. The upper end of the middle part (372) slightly protrudes from the core plate (304). This protrusion amount becomes a fitting amount described later, and the mold clamping force increases or decreases depending on the size of the fitting amount.
A taper part (373) is extended from the end part of the middle part (372). The diameter of the tapered portion (373) decreases from the connecting portion with the middle portion (372) toward the upper tip. In addition, a groove portion (374) that goes around the outer peripheral surface of the taper portion (373) is formed at an intermediate position in the axial direction of the taper portion (373).

FIG. 3 shows an enlarged view of the mold clamping bush (308).
The mold clamping bush (308) has a substantially cylindrical shape with a bottom. A tapered hole (380) is formed in the mold clamping bush (308) in the axial direction inside the mold clamping bush (308). The diameter of the taper hole (380) decreases toward the bottom of the mold clamping bush (308), and the taper angle is formed to be equal to the taper angle of the taper part (373) of the mold clamping pin (307).
The mold clamping bush (308) is housed in a bush housing hole (330) formed in the cavity plate (303). The diameter of the bush housing hole (330) is formed to be equal to or slightly larger than the outer diameter of the mold clamping bush (308). The end face of the mold clamping bush (308) is flush with the lower surface of the cavity plate (303) or is recessed from the lower surface. The tapered hole (380) is exposed on the lower surface (331) side of the cavity plate (303).
A female screw portion (381) is formed at the bottom of the clamping bush (308). From the upper surface of the cavity plate (303), a bolt (382) inserted through a through hole formed in the cavity plate (303) is screwed into the female screw portion (381), and the mold clamping bush (308) is inserted into the cavity plate. (303) Fix inside.
A spacer (not shown) may be inserted between the bottom surface of the bush housing hole (330) and the bottom surface of the mold clamping bush. By changing the thickness of the spacer, the position of the mold clamping bush (308) can be changed to a desired position inside the cavity plate (303). As will be described later, the mold clamping pin (307) and the mold are fixed. The fitting amount with the clamping bush (308) can be adjusted, and the mold clamping force can be adjusted.

FIG. 4 shows the mold apparatus (300) in a clamped state.
From the state shown in FIG. 1, the hydraulic cylinder (314) is operated, the bottom plate (315) and the parts connected to the bottom plate (315) are pushed up, the mold clamping pin (307) and the mold clamping bush (308) are fitted, and the core The upper surface of the plate (304) is brought into contact with the lower surface of the cavity plate (303).
In the example shown in FIG. 4, a substantially cylindrical shaped core (340) is formed on the upper surface of the core plate (304). In addition, a recess (332) is formed on the lower surface of the cavity plate (303) so as to surround the upper surface and the peripheral surface of the molding core (340) with a certain distance. A space is formed between the molding core (340) and the recess (332), and this space becomes a cavity (305) that imitates a plastic molded product. In the present embodiment, the cavity (305) is a one-end-bottomed cylindrical space, so that the molded plastic product is a one-end-bottomed cylinder. In addition, the shape of a shaping | molding core (340) and a recessed part (332) is not restricted to this, It determines suitably according to a desired molded article shape.
A supply path (306) through which molten plastic injected from the injection nozzle (301) flows is formed in the cavity plate (303) and communicates with the cavity (305). In the vicinity of the connection portion between the supply path (306) and the cavity (305), the supply path (306) has a tapered shape with a cross-sectional area that decreases downward.
In the vicinity of the upper surface of the cavity plate (303), the cross-sectional area of the supply path (306) becomes large, and a liquid reservoir (360) is formed.

The injection nozzle (301) includes an attachment portion (316) connected to the top plate (302), and a nozzle portion (317) penetrating the top plate (302) and the stripper plate (309).
The upper portion of the nozzle portion (317) has a cylindrical shape formed with a large diameter, and the lower portion has a two-stage cylindrical shape with a cylindrical shape formed with a smaller diameter than the upper portion. Inside the nozzle portion (317), a tapered molten plastic injection hole whose cross-sectional area increases is formed at the lower side, and is connected to the supply path (306). The lower end surface of the injection nozzle (301) is flush with the lower surface of the stripper plate (309).
The molten plastic injected from the injection nozzle (301) passes through the nozzle portion (317) and the supply path (306) and is supplied into the cavity (305).

FIG. 5 is a state diagram at the moment when the mold clamping pin (307) is inserted into the mold clamping bush (308) during the mold clamping operation of the plastic injection mold apparatus (300).
As shown in FIG. 5, due to the tapered shape formed on the tip of the clamping pin (307) and the inner wall of the clamping bush (308), there is a gap between the outer wall surface of the clamping pin (307) and the inner wall surface of the clamping bush (308). After the mold clamping pin (307) is inserted into the mold clamping bush (308), there is no contact, and a gap (d) is formed between these wall surfaces. The gap (d) is maintained until a clamping pin (307) described later and a clamping bush (308) are fitted.
Therefore, in order to insert the clamping pin (307) into the clamping bush (308), high kinetic energy is given to the clamping plate (307) and the core plate (304) on which the clamping pin (307) is installed. There is no need, and the core plate (304) can be moved at a speed lower than the moving speed of the core plate during the clamping operation of the conventional plastic injection mold apparatus. Thereby, it becomes easy to detect the molded product adhering to the core plate (304) side, in particular, the mold clamping pin (307) by the foreign matter sensor or the like during the mold clamping operation of the plastic injection mold device (300). In addition, the movement of the core plate (304) is stopped after the foreign matter is detected by the foreign matter sensor or the like, but the moving speed of the core plate (304) is reduced as compared with the conventional plastic injection mold apparatus. The braking distance until the core plate (304) stops is shortened, and the risk of damage to the plastic injection mold device (300) due to foreign matter is reduced.

FIG. 6 shows a state in which the mold clamping pin (307) further enters the mold clamping bush (308) from the state shown in FIG. 5, and the mold clamping pin (307) and the mold clamping bush (308) are in the fitted state. FIG.
In this embodiment, the diameter of the connecting portion between the tapered portion (373) and the middle portion (372) of the clamping pin (307) is equal to the diameter of the tapered hole (380) at the opening end surface of the clamping bush (308). Are equally formed. Therefore, the taper of the mold clamping pin (307) is not the first time when the connecting portion between the taper portion (373) and the middle portion (372) of the mold clamping pin (307) reaches the opening end face of the mold clamping bush (308). The entire outer peripheral surface of the portion (373) comes into contact with the inner peripheral surface of the mold clamping bush (308). Since this contact occurs simultaneously on the entire outer peripheral surface of the taper portion (373), the impact caused by the contact is dispersed without being concentrated on a part of the mold clamping pin (307), so that damage to the mold clamping pin (307) is reduced. The
From this state, the mold clamping pin (307) is further moved toward the bottom surface of the mold clamping bush (308) by the kinetic energy applied to the mold clamping pin (307) and the core plate (304) to which the mold clamping pin (307) is connected. It will be pushed in.
Since the mold clamping bush (308) is stored in a bush housing hole (330) formed in the cavity plate (303) with its outer wall in contact, the mold clamping pin (307) is further pushed in. Sometimes the outer peripheral wall of the clamping bush (308) is compressed, and compressive stress is generated inside the outer peripheral wall of the clamping bush (308).
This compressive stress acts to clamp the mold clamping pin (307) that fits with the mold clamping bush (308), and the mold clamping bush (308) and the mold clamping pin (307) are firmly fitted to each other, and the molten plastic The mold clamping force is sufficient to counter the injection pressure.

In the present embodiment, as described above, the groove pin (374) is formed in the mold clamping pin (307). When the mold clamping pin (307) is pushed into the mold clamping bush (308), the portion of the mold clamping pin (307) in which the groove (374) is formed is easily compressed and deformed. .
By this compressive deformation, the groove (374) acts as a spring, and the portion of the clamping pin (307) located on the tip side of the groove (374) is pressed against the inner peripheral surface of the clamping bush (308) with a strong force. It becomes. Therefore, a higher compressive stress is generated inside the wall surface of the mold clamping bush (308) that is in contact with the part of the mold clamping pin (307) on the tip side of the groove (374), and the mold clamping pin (307) The tip end portion is fitted more firmly.
As shown in a test example to be described later, the mold clamping pin (307) and the mold clamping bush (308) are coupled with a very strong force by the mold clamping structure including the mold clamping pin (307) and the mold clamping bush (308). . Therefore, even if the molten plastic is injected from the injection nozzle (301) at a high pressure, the clamping pin (307) does not descend against the injection pressure, and fixes the position of the core plate (304).

As described above, the fitting between the clamping pin (307) and the clamping bush (308) is not due to the frictional force between the outer peripheral surface of the clamping pin (307) and the inner peripheral surface of the clamping bush (308). This is due to the compressive force generated by the tapered shape of each other. Therefore, there is no loss due to friction that occurs when the clamping pin (307) is inserted into the clamping bush (308), and the energy required for fitting compresses and deforms the wall of the clamping bush (308). Only the energy required to make it happen.
Therefore, after the tip of the mold clamping pin (307) has entered the mold clamping bush (308), the moving speed of the core plate (304) may be increased, and the mold clamping pin (307) is placed in the mold clamping bush (308). There is no need to enter at high speed. Therefore, most of the moving distance of the core plate (304) is moved at a low speed, and when foreign matter adheres to the upper surface of the core plate (304) or the mold clamping pin (307), it becomes easy to detect the foreign matter with a sensor, The risk of breakage of the core plate (304), cavity plate (303), clamping pin (307) and clamping bush (308) is reduced. Further, the movement of the core plate (304) at a low speed results in a shortening of the braking distance required for the stop operation at the time of foreign object detection, and further reduces the risk of damage to the mold apparatus (300). It will be a thing.
Thus, it is preferable to use a drive source that can control the movement of the core plate (304) at two speeds, a low speed and a high speed, in the mold apparatus (300). In the example shown in FIG. 4, the hydraulic cylinder (314) is used, but when the movement is started, a low hydraulic pressure is supplied to the hydraulic cylinder (314), and the tip of the mold clamping pin (307) is located at the mold clamping bush (304). If the high hydraulic pressure is supplied after the insertion, the low-speed and high-speed operation of the core plate (304) as described above can be realized. When the core plate (304) is moved by the motor, the moving speed of the two-stage core plate (304) can be realized by switching the motor rotation speed from low speed to high speed.
As another method, the plastic injection mold apparatus (300) may further include an impact force supply source that applies an impact force to the core plate. The outer periphery of the taper portion (373) of the clamping pin (307) is moved at a low speed until it abuts against the inner wall surface of the clamping bush (304), and then is moved upward to the core plate (304) side component by an impact force supply source. The impact force is urged toward the wall, so that the wall of the clamping bush (308) can be compressed and deformed. An example of the pressure supply source is an air cylinder to which compressed air is supplied.

7 to 10 show the molded product take-out process.
As shown in FIG. 7, after the molten plastic is molded in the cavity (305), both the cavity plate (303) and the components connected to the lower side of the cavity plate (303) are lowered while being guided by the guide rod (313). As a result, the cavity plate (303) is separated from the stripper plate (309).
As described above, since the supply path (306) formed in the cavity plate (303) has a tapered shape that narrows downward, the resin in the supply path (306) does not follow the lowering of the cavity plate (303). It will stay on the lower surface of the stripper plate (9).
On the other hand, the plastic resin in the cavity (305) is entirely surrounded by the cavity plate (303) and the core plate (304), and follows the lowering of the cavity plate (303) and the core plate (304). It becomes. In this way, the plastic in the cavity (305) and the plastic in the supply path (306) are separated.
The connection portion between the supply path (306) and the cavity (305) is formed to be smaller than the cross section of the other part of the supply path (306). Therefore, the separation point of the plastic is surely a connection portion between the supply path (305) and the cavity (306), and the molded product is not damaged and no protrusion is formed on the molded product.

A round bar-shaped slide bar (319) extends downward from the top plate (302). The slide bar (319) includes an upper head part (320) formed larger in diameter than the slide bar (319) at the upper end. In addition, a lower head (321) having a diameter substantially the same as that of the upper head (320) is formed at the lower end of the slide bar (319).
The upper head part (320) includes a sliding part (323) and a sliding part extending from the lower surface of the locking part (322) and the locking part (322) and having a smaller diameter than the locking part (322). It consists of a thread part (324) extended from the lower surface of the moving part (323). The locking portion (322) is housed in a counterbore hole formed in the top plate (302), and floats upward from the counterbore hole bottom during the mold clamping process shown in FIGS.
The sliding portion (323) passes through a through hole formed integrally with a counterbore hole of the top plate (302). In the state shown in FIG. 7, the bottom surface of the sliding portion (323) is in contact with the top surface of the stripper plate (309). The screw portion (324) passes through a through hole formed in the stripper plate (309), and is screwed with a female screw portion formed on the lower surface of the slide rod (319), so that the upper head portion (320) is engaged with the slide rod (319). Secure to the top.

The bottom plate (315), the spacer (310) and the core plate (304) are formed with through holes having a cross-sectional area larger than that of the lower head (321). On the other hand, the cavity plate (303) has a through-hole that is smaller than the cross-sectional area of the lower head (321) and larger than the cross-sectional area of the slide bar (319).
While the cavity plate (303) is lowered along the guide rod (313) and the slide rod (319), the bottom plate (315), the spacer (310) and the core plate (304) interfere with the lower head (321). It goes down without being done.
Thereafter, the lower surface of the cavity plate (303) contacts the upper surface of the lower head (321).

FIG. 8 shows a state where the cavity plate (303) and the components connected to the cavity plate (303) are further lowered from the state shown in FIG.
When the cavity plate (303) is further lowered from the state in contact with the upper surface of the lower head (321), the sliding portion (323) of the upper head (320) moves downward through the through hole formed in the top plate (302). The slide bar (319) is lowered until the lower surface of the locking part (322) comes into contact with the counterbore bottom. The slide bar (319) does not descend any further, and the cavity plate (303) is supported by the lower head (321), so the cavity plate (303) does not descend any further.

When the slide bar (319) is lowered, the lower surface of the sliding part (323) of the upper head part (320) pushes the stripper plate (309) downward. The stripper plate (309) is guided and lowered to the outer peripheral surface of the nozzle portion (317) of the injection nozzle (301).
As described above, the resin in the supply path (306) remains on the lower surface of the stripper plate (309). When the stripper plate (309) is lowered, the resin in the liquid reservoir (360) of the supply path (306) is pushed downward.
Further, as described above, the nozzle portion (317) is formed with a tapered hole that narrows upward. Accordingly, when the resin in the liquid reservoir (360) is pushed downward by the lowering of the stripper plate (309), the resin in the nozzle (317) is further injected into the injection nozzle at the upper end of the nozzle (317). (301) Split with the resin in the back.

FIG. 9 shows a state where the core plate (304) and the parts connected to the lower side of the core plate (304) are further lowered.
As described above, the resin in the nozzle part (317) is separated from the resin in the back of the nozzle part (317) and then taken out from the nozzle part (317). Therefore, when molding the next molded product, since there is no resin remaining in the supply path (306) and the nozzle portion (317), the problem of clogging in the injection nozzle (301) and the supply path (306) does not occur at all. .
The cavity plate (303) is supported by the lower head portion (321) of the slide rod (319) and fixed at that position, while the core plate (304) and the parts connected below the core plate (304) are lower than the lower head portion (321). Since a large through hole is formed, it further descends. Therefore, the cavity plate (303) and the core plate (304) are separated, and the molded product molded in the cavity (305) is exposed on the molded core (340) of the core plate (304).
When the core plate (304) is lowered with respect to the cavity plate (303), the fitting state of the mold clamping pin (307) and the mold clamping bush (308) is released. Due to the tapered shape formed on the clamping pin (307) and the clamping bush (308), frictional wear does not occur while the clamping pin (307) is pulled out from the clamping bush (308).
Note that the screw (381) formed on the bottom of the clamping bush (308) and the bolt (382) for fixing the clamping bush (308) are released, and the cavity plate (303 shown in FIG. ) And the core plate (304) are separated, the mold clamping bush (308) is taken out from the cavity plate (303) while being connected to the tip of the mold clamping pin (307). Since the mold clamping bush (308) can be easily taken out in this manner, the mold clamping bush (308) can be replaced very efficiently.
The lowering of the core plate (304) and the parts connected to the core plate (304) and the bottom plate (315) is such that the lower surface of the spacer (310) disposed between the core plate (304) and the bottom plate (315) is formed at the lower end of the slide bar (313). Continue until it touches the top surface.

FIG. 10 shows a process of extruding a molded product from the core plate (304).
As described above, the pair of spacers (310) are disposed on the left and right ends of the lower surface of the core plate (304). An ejector plate (311) is disposed between the pair of spacers (310). An extraction bar (312) extends upward from the ejector plate (311).
The ejector plate (311) has a shape in which two flat plates are connected vertically. The take-out bar (312) includes a base end part (325) and a round bar-shaped bar body part (326) formed with a smaller diameter than the base end part (325). The take-out bar (312) penetrates from above the flat plate disposed on the upper side of the pair of flat plates, and the base end (325) of the take-out bar (312) is received in a counterbore formed on the lower surface of the flat plate. The flat plate disposed on the lower side supports the lower surface of the base end portion (325) of the take-out bar (312).
The rod part (326) is inserted into a through hole formed in the core plate (304), and slides in the through hole as will be described later. As shown in FIGS. 7 to 9, before the step of extruding the molded product from the core plate (304), the rod body portion (326) is flush with the upper surface of the molded core (340). As a result, unevenness caused by the rod portion (326) is prevented from occurring.

  When the bottom plate (315) reaches the lower limit position defined by the guide rod (313), the ejector plate (311) moves upward. Note that an air cylinder, a hydraulic cylinder, or the like is appropriately used as a means for moving the ejector plate (311). As the ejector plate (311) moves, the take-out bar (312) moves upward, and the upper end surface of the take-out bar (312) pushes the molded product upward. Then, the molded product is pushed up above the molding core (340) and taken out from the mold apparatus (300).

The test example with respect to the clamping force of the clamping fixture based on a present Example is shown below.
There were two types of mold clamping pins (307) used in this test example, and those with a diameter of the intermediate part (372) of 16 mm and 12 mm were prepared. The taper angle of the taper portion (373) of the mold clamping pin (372) is 1.10 °. The axial length of the tapered portion (373) is 38 mm.
In addition, mold clamping bushes (308) corresponding to these mold clamping pins (307) were prepared. The wall thickness of the clamping bush (308) is 7 mm.

  In this test example, the amount of pressing of the mold clamping pin (307) from the state in which the connecting portion of the taper portion (373) and the middle portion (372) of the mold clamping pin (307) coincides with the end surface of the mold clamping bush (308). Defined as a mating amount. That is, the amount of pressing from the position where the outer peripheral surface of the tapered portion (373) of the mold clamping pin (307) and the inner peripheral surface of the mold clamping bush (308) are in contact for the first time is the fitting amount in this test example.

  In this test example, the mold clamping pin (307) is inserted into the mold clamping bush (308), and the mold clamping pin (307) is pushed into the mold clamping bush (308) by a predetermined fitting amount. Fastening pins (307) were secured to the tensile material testing machine. The mold clamping pin (307) was pulled at a tensile speed of 300 mm / min, and the maximum tensile force in the process until the mold clamping pin (307) was pulled out from the mold clamping bush (308) was defined as the mold clamping force.

FIG. 11 shows the results obtained in the above test.
As shown in FIG. 11, when a clamping pin (307) having a pin diameter of 16 mm and a pin diameter of 12 mm is used, a high clamping force of 1000 N or more can be obtained with a fitting amount of 0.3 mm or more. Further, the clamping force increases linearly in proportion to the increase in the fitting amount. Therefore, it is easy to determine the amount of fitting for obtaining a desired clamping force, and the adjustment of the amount of fitting becomes very easy. The fitting amount is adjusted by changing the length of the clamping pin (307), changing the position of the clamping bush (308) in the cavity plate (303), or clamping the core plate (304). The speed can be changed as appropriate by changing the moving speed.
In addition, when the clamping pin (307) with a small pin diameter is used, the change of the clamping force with respect to the fitting amount becomes moderate, and when the clamping pin (307) with a large pin diameter is used, the clamping with respect to the fitting amount is performed. The power changes suddenly. Therefore, when finely adjusting the clamping force, it is preferable to use a clamping pin (307) having a small pin diameter.
It is preferable to obtain the relationship between the fitting amount and the clamping force as shown in FIG. 11 for a plurality of clamping pins (307) and clamping bushes (308) having different shapes or materials. When setting the mating amount based on the relationship between the mating amount and the clamping force, set the mating amount to be less than the allowable burr thickness for the molded product. If a combination of a clamping pin (307) and a clamping bush (308) that can obtain a clamping force that can counter the injection pressure of the molten plastic that is injected is selected, the molded product may be burred due to a malfunction in the clamping process. Even if this occurs, the generated burr can be made smaller than the allowable thickness.

  As described above, when the clamping pin (307) having a tapered shape and the clamping bush (308) are fitted, a large clamping force can be obtained with a small fitting amount. This means that the distance that the outer peripheral surface of the mold clamping pin (307) and the inner wall surface of the mold clamping bush (308) rub against each other is shortened, and wear of the mold clamping pin (307) and the mold clamping bush (308) is reduced. Very small. Further, since the relative moving distance of the wall surfaces in a state where the wall surfaces are in contact with each other is shortened, it is easy to push the mold clamping pin (307) into the mold clamping bush (308) by an impact load. Therefore, after the core plate (304) is moved upward at a low speed at which foreign matter on the core plate (304) can be detected, and the outer peripheral surface of the clamping pin (307) and the inner wall surface of the clamping bush (308) are in contact, By applying an impact force, a high clamping force can be obtained.

  As described above, until the outer peripheral surface of the mold clamping pin (307) comes into contact with the inner wall surface of the mold clamping bush (308), a force against the fitting operation such as friction does not occur. In a state where the outer peripheral surface of the mold clamping pin (307) and the inner wall surface of the mold clamping bush (308) are in contact, a set fitting amount is set between the lower surface of the cavity plate (303) and the upper surface of the core plate (304). A gap equal to As described above, since the mold clamping pin (307) and the mold clamping bush (308) can obtain a large fitting force with a small fitting amount, the set fitting amount can be made extremely small. Accordingly, the gap formed between the lower surface of the cavity plate (303) and the upper surface of the core plate (304) in a state where the outer peripheral surface of the mold clamping pin (307) and the inner wall surface of the mold clamping bush (308) are in contact with each other is also very large. It will be small.

When injection molding is performed in a state where the lower surface of the cavity plate (303) and the upper surface of the core plate (304) are not in contact, the molten plastic is injected into a gap between the lower surface of the cavity plate (303) and the upper surface of the core plate (304). Will enter and cause burrs in the molded product.
As described above, no force against the movement of the mold clamping pin (307) is generated until the outer peripheral surface of the mold clamping pin (307) and the inner wall surface of the mold clamping bush (308) abut. Further, the gap formed between the lower surface of the cavity plate (303) and the upper surface of the core plate (304) in a state where the outer peripheral surface of the mold clamping pin (307) and the mold clamping bush (308) are in contact with each other is very narrow. Become. The mold clamping pin (307) is pushed further into the mold clamping bush (308) from the state where the outer peripheral surface of the mold clamping pin (307) and the inner wall surface of the mold clamping bush (308) are in contact with each other. ) In the mold clamping bush (308) is insufficient, the gap formed between the lower surface of the cavity plate (303) and the upper surface of the core plate (304) is always larger than the set fitting amount. Get smaller.
That is, if the mold clamping structure comprising the mold clamping pin (307) and the mold clamping bush (308) according to the present invention is used, the thickness of the burr generated due to the malfunction of the mold clamping process can be made thinner than the set fitting amount. Can be guaranteed.

  The present invention can fix the position of the core plate without depending on the frictional force, can reduce the moving speed of the core plate during the mold clamping operation, facilitates the detection of foreign matter attached to the core plate, A plastic injection mold device capable of preventing damage to the plate and the cavity plate and obtaining a desired clamping force; a method for producing a plastic molded product using the plastic injection mold device; The present invention is suitably applied to a plastic injection molded product obtained from a plastic injection mold apparatus and a mold clamping structure of a plastic injection mold apparatus.

It is a figure which shows the state before the mold clamping of the plastic injection mold which concerns on this invention. It is a figure which shows the clamping pin which concerns on this invention. It is a figure which shows the mold clamping bush which concerns on this invention. It is a figure which shows the clamping state of the plastic injection molding die apparatus which concerns on this invention. It is a figure which shows the state by which a mold clamping pin is inserted in a mold clamping bush. It is a figure which shows the state which the mold clamping pin fitted with the mold clamping bush. It is a figure which shows one process among the molded article extraction processes of the plastic injection molding die apparatus which concerns on this invention. It is a figure which shows one process among the molded article extraction processes of the plastic injection molding die apparatus which concerns on this invention. It is a figure which shows one process among the molded article extraction processes of the plastic injection molding die apparatus which concerns on this invention. It is a figure which shows one process among the molded article extraction processes of the plastic injection molding die apparatus which concerns on this invention. It is a figure which shows the result of the test with respect to the clamping force of the clamping fixture which concerns on this invention. It is a figure which shows the conventional plastic injection molding die apparatus. It is a figure which shows the process of taking out the molded product shape | molded from the plastic injection molding die apparatus shown in FIG. (A) shows a plastic injection mold apparatus, (b) shows the molded product taken out from the plastic injection mold apparatus. It is a figure which shows the other form of the conventional plastic injection molding die apparatus. It is a figure which shows 1 process of the molded article extraction process of the plastic injection molding die apparatus shown by FIG. It is a figure which shows 1 process of the molded article extraction process of the plastic injection molding die apparatus shown by FIG. It is a figure which shows 1 process of the molded article extraction process of the plastic injection molding die apparatus shown by FIG. It is a figure which shows the state before the mold clamping of the plastic injection molding die apparatus shown by FIG. 14 thru | or FIG.

Explanation of symbols

300 ... Plastic injection mold device 301 ... Injection nozzle 303 ... Cavity plate 304 ... Core plate 305 ... Cavity 306 ... Supply path 307 ... Clamp pin 308 ... Clamping bush 309 ... Stripper plate 314 ... Drive source 374 ... Groove 381 ... Female thread 382 ... Bolt

Claims (11)

A plastic injection comprising a cavity plate for molding one side of a molded product and a core plate disposed below the cavity plate, and a cavity imitating the molded product is formed in a state where the cavity plate and the core plate are in contact with each other A molding die device,
An injection nozzle for injecting molten plastic resin is disposed above the cavity plate,
A supply path for supplying the molten plastic injected from the injection nozzle into the cavity is formed inside the cavity plate,
From the lower surface of the cavity plate, one end bottomed cylindrical clamping bush is embedded with the opening exposed to the lower surface of the cavity plate,
Below the core plate, a drive source for moving the core plate up and down is disposed,
On the upper surface of the core plate, a clamping pin that protrudes from the upper surface of the core plate and fits with the clamping bush is implanted.
The protruding portion of the clamping pin is formed in a tapered cylindrical shape that decreases in diameter toward the upper side,
2. The plastic injection mold apparatus according to claim 1, wherein the mold clamping bush has a taper hole having a taper angle substantially equal to a taper shape of the projecting portion of the mold clamp pin and a diameter decreasing upward. A stripper plate is disposed between the cavity plate and the injection nozzle,
The cavity plate can be moved up and down below the stripper plate;
2. The plastic injection mold apparatus according to claim 1, wherein a cross-sectional area of the supply path is gradually reduced downward. The drive source raises the core plate at a predetermined speed until the tip of the clamping pin passes through the clamping bush opening surface,
The plastic injection molding apparatus according to claim 1 or 2, wherein the core plate is accelerated and raised after the tip of the mold clamping pin passes through the opening surface of the mold clamping bush. The plastic injection mold apparatus further comprises an impact force supply source for imparting an impact force to the core plate,
The drive source raises the core plate at a predetermined speed until the outer peripheral surface of the clamping pin contacts the inner wall surface of the clamping bush,
3. The impact force supply source applies an impact force upward to the core plate after the outer peripheral surface of the clamping pin abuts against the inner wall surface of the clamping bush. Plastic injection mold equipment. A step of raising a core plate for molding one surface of a molded product, bringing it into contact with a cavity plate disposed above the core plate, and forming a cavity imitating the molded product between the core plate and the cavity plate When,
Injecting molten plastic into the cavity, and molding the plastic into the shape of the cavity;
Lowering the core plate relative to the cavity plate to expose the molded plastic;
The process comprises removing the molded plastic from the mold,
In the step of forming the cavity,
The tip of the clamping pin that protrudes from the core plate and is tapered and narrows upward is embedded in the cavity plate to form a cylindrical shape with one end and a taper angle substantially equal to the clamping pin. The core plate rises at a predetermined speed until it passes through the opening surface of the clamping bush having a tapered hole that is narrowly formed upward at
A method for producing a plastic molded product, wherein the mold clamping pin rises at a speed higher than the predetermined speed after passing through the opening surface of the mold clamping bush. A step of raising a core plate for molding one surface of a molded product, bringing it into contact with a cavity plate disposed above the core plate, and forming a cavity imitating the molded product between the core plate and the cavity plate When,
Injecting molten plastic into the cavity, and molding the plastic into the shape of the cavity;
Lowering the core plate relative to the cavity plate to expose the molded plastic;
The process comprises removing the molded plastic from the mold,
In the step of forming the cavity,
A mold clamping pin outer peripheral surface that protrudes from the core plate and is tapered and narrows upward is embedded in the cavity plate and formed into a cylindrical shape with one end and a taper angle substantially equal to the mold clamping pin. The core plate rises at a predetermined speed until it comes into contact with the inner wall surface of the clamping bush having a tapered hole that is formed thinly upward at
A method for producing a plastic molded product, wherein an impact force is applied upward to the core plate after the outer peripheral surface of the clamping pin abuts against the inner wall surface of the clamping bush. After the step of molding a plastic molded product in the cavity, before lowering the core plate,
7. The method according to claim 5, further comprising a step of lowering both the cavity plate and the core plate with respect to an injection nozzle that is disposed above the cavity plate and injects molten plastic into the cavity. The manufacturing method of the plastic molded product of description. A die having an outer peripheral surface of a mold clamping pin that is tapered and tapered upward, and a tapered hole that is formed in a cylindrical shape with one bottom and that is tapered toward the bottom at a taper angle substantially equal to the mold clamping pin. A fitting amount defined as an amount by which the clamping pin is pushed into the clamping bush from a state in which the inner wall surface of the clamping bush is in contact; and the clamping pin and the clamping bush with respect to the fitting amount The relationship between the fitting force between the clamping pins and the clamping bushes of different shapes,
A mold that can determine a fitting amount smaller than the allowable burr thickness for a plastic molded product, and obtain a fitting force that can counter the injection pressure of the molten plastic from the relationship between the fitting amount and the fitting force. Select clamping pin and clamping bush,
According to the determined fitting amount, the selected clamping pin protrudes from the upper surface of the core plate, and the selected clamping bush is embedded in the cavity plate,
Contacting the core plate with the cavity plate to form a cavity between the core plate and the cavity plate;
The molten plastic is injected into the cavity from an injection nozzle disposed above the cavity plate through a supply path formed inside the cavity plate, and the plastic is molded in the cavity.
A plastic molded article obtained by lowering both the cavity plate and the core plate with respect to the injection nozzle and separating the plastic resin remaining in the supply path and the plastic resin in the cavity. In the plastic injection mold, the cavity plate is disposed on the side for injecting the molten plastic resin and forms one surface of the plastic molded product,
A mold clamping fixture for clamping and fixing between a core plate for molding the other one surface of the plastic molded article,
The mold clamping fixture is embedded in the cavity plate, and has a substantially one-end-bottomed cylindrical mold clamping bush that exposes its opening to the molding surface of the cavity plate;
The mold plate is embedded in the core plate, protrudes from the molding surface of the core plate, and includes a mold clamping pin that fits with the mold clamping bush.
The inner wall surface of the clamping bush is formed in a tapered shape whose diameter decreases toward the bottom surface,
The mold clamping pin is characterized in that the mold clamping pin has a taper angle substantially equal to a taper angle of a taper shape of an inner wall surface of the mold clamping bush and decreases in diameter toward the tip thereof. A female screw portion is formed at the bottom of the clamping bush,
A bolt is screwed into the female thread portion through a through hole formed on the surface opposite to the molding surface of the cavity plate,
The mold clamping fixture according to claim 9, wherein the mold clamping bush is movable in the cavity plate in an axial direction of the mold clamping bush. The mold clamping fixture according to claim 9 or 10, wherein a groove is formed on an outer peripheral surface of the mold clamping pin in an intermediate portion in the axial direction of the mold clamping pin.

Images