JP2004160872A - Injection molding device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a molding material from flowing into a valve sleeve pin at the time of purge. <P>SOLUTION: The injection molding device is provided with a mold 2 having a fixing mold 10 and a movable mold 3 which can be relatively closed and opened and forms a cavity 39 between them when closed, a nozzle 18 fixed to the fixing mold 10 side and injecting and filling a molding material into the cavity 39, a valve sleeve pin 34 opening and closing the nozzle 18, and a core pin 9 provided to the movable mold 3 side, with its tip end inserted into the valve sleeve pin 34 in closing the mold 2. A valve center pin 36 is inserted into the valve sleeve pin 34 movably in a vertical direction, allowing the valve center pin 36 to close the opening part of the valve sleeve pin 34 at the time of purging the molding material through the nozzle 18. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an injection molding apparatus, and more particularly, to an injection molding apparatus effective for molding a molded article having a syringe shape.
[0002]
[Prior art]
Conventionally, as an example of an injection molding apparatus for molding a syringe-shaped molded article 40 as shown in FIG. 4, a fixed mold and a movable mold which are provided so that a mold clamping mold can be opened relatively are provided. A molding die that forms a cavity between both dies during mold clamping, a hot nozzle that is provided on the fixed die side and that injects and fills the molding material into the cavity, and a hot nozzle that is movably inserted in the vertical direction A valve sleeve pin that opens and closes the hot nozzle, a core that is provided on the movable mold side, and that forms the lower half of the cavity in cooperation with the fixed mold during mold clamping, There is also known a device provided with a core pin that forms the upper half of a cavity in cooperation with a fixed mold at the time of mold clamping.
[0003]
Then, in order to mold a syringe-shaped molded article using the injection molding apparatus having the above-described configuration, the movable mold is brought into contact with the fixed mold, and the mold is clamped. The lower half of the cavity is formed between the core and the fixed mold, and the tip of the core pin is inserted into the valve sleeve pin on the fixed mold side. A half is formed and a syringe-shaped cavity is formed between the fixed mold and the movable mold.
[0004]
In this state, the hot nozzle is opened by the valve sleeve pin, the molding material is injected and filled into the cavity via the hot nozzle, the hot nozzle is closed by the valve sleeve pin, and the molding material is sealed in the cavity.
[0005]
This state is maintained for a predetermined time, and after the molding material is cured in the cavity, the movable mold is separated from the fixed mold and the mold is opened to form a syringe that matches the shape of the cavity. Can be molded. Conventionally, various types of such injection molding apparatuses have been provided (for example, see Patent Document 1).
[0006]
[Patent Document 1]
JP-A-11-90963 (pages 4-6, FIGS. 1-7)
[0007]
[Problems to be solved by the invention]
By the way, when molding a molded article by the injection molding apparatus having the above-described configuration, before starting the molding operation, it is tested whether or not the molding material is injected from the hot nozzle and remains in the hot nozzle. A purge operation for discharging the deteriorated molding material from the hot nozzle is performed.
[0008]
However, in the injection molding apparatus having the above configuration, when the molding material is injected from the hot nozzle during the purging operation, the molding material enters the valve sleeve pin from the opening of the valve sleeve pin. And the molding material is clogged in the valve sleeve pin. For this reason, when the molding die is clamped during the molding operation and the core pin is inserted into the valve sleeve pin, the tip of the core pin hits the molding material in the valve sleeve pin, and further into the valve sleeve pin. Is prevented, the core pin may be bent or damaged.
[0009]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and prevents a molding material from flowing into a valve sleeve pin on a fixed mold side at the time of purging. When the core pin is inserted into the valve sleeve pin, the core pin can be inserted into the valve sleeve pin without resistance, preventing the valve sleeve pin from being bent or damaged. It is an object of the present invention to provide an injection molding device that can completely prevent the injection molding.
[0010]
[Means for Solving the Problems]
The present invention employs the following means in order to solve the above problems. That is, the invention according to claim 1 has a fixed mold and a movable mold that are relatively openably provided in a mold, and forms a cavity between the molds when the molds are clamped. A mold, a nozzle provided on the fixed mold side, for injecting and filling a molding material into the cavity, a valve sleeve pin for movably inserting the nozzle vertically, and opening and closing the nozzle, And a core pin provided at the mold side and having a tip inserted into the valve sleeve pin at the time of clamping of the molding die. The opening of the valve sleeve pin is closed by the valve center pin when the molding material is purged from the nozzle.
According to the injection molding apparatus of the present invention, when the molding material is purged from the nozzle, the opening of the valve sleeve pin is closed by the center pin, so that the molding material flows into the valve sleeve pin. There is no such thing.
[0011]
The invention according to claim 2 is the injection molding apparatus according to claim 1, wherein the valve center pin is urged by an urging member when purging molding material from a nozzle, and the valve sleeve is urged by the urging member. When closing the opening of the pin and closing the molding die, the pin is pressed by the core pin and moves in the valve sleeve pin against the urging member, and moves into the valve sleeve pin of the core pin. Is allowed. According to the injection molding apparatus of the present invention, when the molding material is purged from the nozzle, the center pin is urged by the urging member and moves inside the valve sleeve pin to close the opening of the valve sleeve pin. However, the molding material is prevented from flowing into the valve sleeve pin. When the mold is closed, the molding pin is pressed by the core pin to move in the valve sleeve pin against the urging member, thereby allowing the core pin to be inserted into the valve sleeve pin. .
[0012]
The invention according to claim 3 is the injection molding device according to claim 1, wherein the valve center pin is movable in the valve sleeve pin by operation of a driving device, and is formed from the nozzle. At the time of purging the material, the operation of the driving device moves the valve sleeve pin to close the opening of the valve sleeve pin, and at the time of clamping the molding die, the driving device Actuation allows the core pin to move within the valve sleeve pin and allow the core pin to be inserted into the valve sleeve pin.
According to the injection molding apparatus of the present invention, when the molding material is purged from the nozzle, the center pin moves within the valve sleeve pin by the operation of the driving device to close the opening of the valve sleeve pin. Prevents material from flowing into the valve sleeve pin. When the mold is clamped, the drive device operates to move the inside of the valve sleeve pin, thereby allowing the core pin to be inserted into the valve sleeve pin.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention shown in the drawings will be described.
FIGS. 1 to 3 show an embodiment of an injection molding apparatus according to the present invention. The injection molding apparatus 1 includes a fixed mold 10 and a movable mold which are relatively openably opened. A molding die 2 having a mold 3 and forming a cavity 39 between the two dies 10 and 3 when clamping the two dies 10 and 3; A hot nozzle 18, which is a nozzle for injecting and filling a molding material, a valve sleeve pin 34 for opening and closing the hot nozzle 18, a valve center pin 36 for inserting the valve sleeve pin 34, and a mold provided on the movable mold 3 side, A core 7 and a core pin 9 which form a cavity 39 in cooperation with the fixed mold 10 when the mold 2 is clamped are provided.
[0014]
As shown in FIGS. 1 and 2, the movable mold 3 has a plate shape having a through hole 4 penetrating in the vertical direction at the center, and is provided to be movable in the vertical direction. It is fixed in a mounting hole 6 on the upper surface side of the holding plate 5 by a bolt (not shown), and can be vertically moved integrally with the movable mold holding plate 5.
A substantially cylindrical core 7 is integrally mounted in the through hole 4 at the center of the movable mold 3 with its upper half protruding upward from the upper surface of the movable mold 3. The upper half portion is inserted into a large-diameter portion 12 of a through-hole 11 of a fixed mold 10 to be described later when the mold 2 is clamped.
[0015]
A through hole 8 penetrating in the vertical direction is provided in the center of the core 7, and a round bar-shaped core pin 9 has an upper end projecting upward from the upper end surface of the core 7 in the through hole 8. The upper end of the core pin 9 is inserted into the small-diameter portion 13 of the through hole 11 of the fixed die 10 described later when the molding die 2 is clamped, and the valve sleeve pin 34 described later. To be inserted into the inner diameter side of the.
[0016]
As shown in FIGS. 1 to 3, the fixed mold 10 has a plate shape having a through hole 11 penetrating in the vertical direction at the center, and is provided above the movable mold holding plate 5. The fixed mold holding plate 14 is integrally mounted in the through hole 15.
[0017]
As shown in FIG. 2, the through hole 11 at the center of the fixed mold 10 has a large-diameter portion 12 located in the lower half of the fixed mold 10 and a fixed-diameter 10 connected to the large-diameter portion 12. A small-diameter portion 13 having a smaller diameter than the large-diameter portion 12 located in the half portion, and is provided in the large-diameter portion 12 of the through hole 11 of the fixed die 10 above the core 7 when the mold 2 is clamped. The half portion is inserted, and the core pin 9 is inserted through the small diameter portion 13.
[0018]
As shown in FIG. 1, a fixed mold receiving plate 16 is provided on the upper part of the fixed mold holding plate 14, and a portion corresponding to the fixed mold 10 of the fixed mold receiving plate 16 is vertically penetrated. In this state, a through hole 17 is provided, and a hot nozzle 18 is provided in the through hole 17.
[0019]
A hot nozzle receiving plate 20 is provided at the lower end of the through hole 17, and the lower end of the hot nozzle 18 is fitted into a through hole 21 provided at the center of the hot nozzle receiving plate 20. .
[0020]
A storage chamber 23, which is a conical cylindrical space, is provided between the inner peripheral surface of the through hole 21 of the hot nozzle receiving plate 20 and the lower end peripheral surface of the hot nozzle 18. A part of the molding material injected from 18 is stored.
[0021]
The lower end of the through hole 21 of the hot nozzle receiving plate 20 is formed as an injection hole 22 communicating with the upper end opening of the through hole 11 of the fixed mold 10, and the molding material from the hot nozzle 18 is supplied through the injection hole 22. It is supplied to the fixed mold 10 side.
[0022]
A supply hole 19 is provided at the center of the hot nozzle 18 in a vertically penetrating state. The supply hole 19 communicates with a supply hole 25 of a manifold 24 provided above the hot nozzle 18 to supply the manifold 24. The molding material is supplied from the hole 25 to the fixed mold 10 via the supply hole 19 of the hot nozzle 18.
[0023]
As shown in FIG. 1, a fixed mold mounting plate 26 is provided above the fixed mold receiving plate 16. A cylinder hole 27 is provided at the center of the fixed mold mounting plate 26 so as to penetrate vertically, and a valve cylinder 28 for vertically driving a valve sleeve pin 34 described later is provided in the cylinder hole 27. It is supposed to be.
[0024]
The valve cylinder 28 closes an upper end opening of the cylinder tube 29 fitted in the cylinder hole 27 of the fixed mold mounting plate 26 and the cylinder hole 27, and holds the cylinder tube 29 in the cylinder hole 27. It has a lid 30 and a piston 31 provided in the cylinder tube 29 so as to be movable in the vertical direction.
[0025]
A mounting hole 32 is provided at the center of the piston 31 so as to penetrate in the vertical direction. A valve sleeve pin 34 is integrally mounted in the mounting hole 32 via a holding member 33, and is vertically integrated with the piston 31. It is designed to be driven in the direction.
[0026]
On the outer peripheral side of the piston 31, a piston portion 35 that protrudes annularly outward in the radial direction is integrally provided, and pneumatically or pneumatically or via a supply hole in an upper space and a lower space of the piston 35. Hydraulic fluid pressure is supplied.
[0027]
Then, by supplying the fluid pressure from the supply hole into the upper space of the piston portion 35 of the piston 31, the piston 31 is driven downward, and the fluid pressure is supplied from the supply hole into the upper space of the piston portion 35 of the piston 31. Is supplied, the piston 31 is driven upward.
[0028]
The valve sleeve pin 34 has a cylindrical shape, penetrates the manifold 24 in the vertical direction, inserts the supply hole 19 of the hot nozzle 18, and inserts the tip into the injection hole 22 of the hot nozzle receiving plate 20. It is possible. By inserting the valve sleeve pin 34 into the injection hole 22, injection of the molding material from the hot nozzle 18 into the cavity 39 is prevented, and by separating the valve sleeve pin 34 from the injection hole 22, the hot nozzle Injection of the molding material from 18 into the cavity 39 is permitted.
[0029]
A valve center pin 36 is inserted through the center of the valve sleeve pin 34 so as to be vertically movable. The valve center pin 36 has a round bar shape, and its upper end is located in an urging chamber 37 provided inside the lid 30 of the fixed mold mounting plate 26, and is provided in the urging chamber 37. The urging member 38 is always urged downward. When the mold 2 is opened, the valve center pin 36 is flush with the tip of the valve sleeve pin 34 to close the opening of the valve sleeve pin 34 as shown in FIG. When the valve sleeve pin 34 opens the injection hole 22, the distal end projects slightly downward from the distal end of the valve sleeve pin 34, as shown in FIG. 3.
[0030]
In order to form a syringe-shaped molded article 40 by the injection molding apparatus 1 according to this embodiment configured as described above, the valve cylinder 28 is operated as shown in FIG. Then, the valve sleeve pin 34 is raised, and the injection hole 22 is opened to test whether the molding material is injected from the supply hole 19 of the hot nozzle 18 through the injection hole 22, that is, purge is performed.
[0031]
Then, after confirming that the molding material has been injected from the injection hole 22, as shown in FIG. 2, the piston 31 of the valve cylinder 28 is lowered, and the valve sleeve pin 34 is lowered integrally with the piston 31, The injection hole 22 is closed at the lower end of the valve sleeve pin 34.
[0032]
Then, the movable mold 3 is moved upward together with the movable mold holding plate 5 from the mold open state shown in FIG. 2, and the upper surface of the movable mold 3 is moved to the lower surface of the fixed mold 10 as shown in FIG. And the mold 2 is clamped.
[0033]
In this case, the upper half of the core 7 on the movable mold 3 side is inserted into the large diameter portion 12 of the through hole 11 of the fixed mold 10, and the lower end of the valve sleeve pin 34 is inserted into the injection hole 22. . The upper end of the core pin 9 is inserted through the small-diameter portion 13 of the through hole 11 of the fixed mold 10 and inserted into the inner diameter side of the valve sleeve pin 34, and resists the urging force of the urging member 38 against the valve center pin 36. , And the centering is performed by the core pin 9 and the valve sleeve pin 34, so that a cavity 39 having a substantially syringe shape is formed between the movable mold 3 and the fixed mold 10.
[0034]
Then, in this state, the piston 31 of the valve cylinder 28 is raised, the valve sleeve pin 34 is raised integrally with the piston 31 to open the injection hole 22, and the supply hole 19 of the hot valve 18 passes through the injection hole 22. The cavity 39 is filled with a molding material by injection.
[0035]
Then, the piston 31 of the valve cylinder 28 is lowered, the valve sleeve pin 34 is lowered integrally with the piston 31, the lower end of the valve sleeve pin 34 is inserted into the injection hole 22, and the injection hole 22 is closed. The molding material is sealed in the cavity 39, and this state is maintained for a predetermined time to cure the molding material.
[0036]
After the molding material has hardened, the movable mold 3 is moved downward integrally with the movable mold holding plate 5 to be separated from the fixed mold 10, and the mold 2 is opened. In this way, a substantially syringe-shaped molded article 40 conforming to the shape of the cavity 39 can be molded.
[0037]
In the injection molding apparatus 1 according to this embodiment configured as described above, the molding material is purged before starting the molding operation, and the molding material is purged from the supply hole 19 of the hot nozzle 18 through the injection hole 22. When injected, the valve center pin 36 is inserted into the valve sleeve pin 34 and the opening of the valve sleeve pin 34 is closed by the valve center pin 36, so that the molding material flows into the valve sleeve pin 34. There is no such thing.
[0038]
Therefore, since the molding material does not flow into the valve sleeve pin 34 and becomes clogged, the core pin 9 becomes clogged in the valve sleeve pin 34 when the molding die 2 is clamped during the molding operation. Thus, there is no possibility that the molding material 40 is bent or damaged by hitting the molding material, and the molded product 40 of stable quality can be molded.
[0039]
FIGS. 5 to 7 show another embodiment of the injection molding apparatus according to the present invention. The injection molding apparatus 1 is configured such that a valve center pin 36 is vertically moved by a purge cylinder 45 as a driving device. It is configured to be driven, and other configurations are the same as those described in the above embodiment.
[0040]
That is, a purge cylinder hole 46 is formed in the center of the lid 30 of the valve cylinder 28, and a purge piston 47 is provided in the purge cylinder hole 46 so as to be vertically movable so as to constitute a purge cylinder 45. The upper end of the valve center pin 36 is integrally fixed to the center of the purge piston 47 of the purge cylinder 45.
[0041]
In this case, pneumatic or hydraulic fluid pressure is supplied to the upper space and the lower space of the purge piston 47 via the upper supply hole 48 and the lower supply hole 49, respectively. I have.
[0042]
When the fluid pressure is supplied from the upper supply hole 48 into the space on the upper surface side, the purge piston 47 moves downward in the purge cylinder hole 46 as shown in FIG. Moves downward integrally with the purge piston 47 and supplies fluid pressure from the lower supply hole 49 into the space on the lower surface side, as shown in FIG. The valve sleeve pin 36 moves upward together with the purge piston 47.
[0043]
Also, in the injection molding apparatus 1 shown in this embodiment, similarly to the injection molding apparatus shown in the above embodiment, the molding material is purged before the molding operation is started, and the injection material is injected from the supply hole 19 of the hot nozzle 18. When the molding material is injected through the hole 22, the valve center pin 36 is inserted into the valve sleeve pin 34, and the opening of the valve sleeve pin 34 is closed by the valve center pin 36. It does not flow into the valve sleeve pin 34.
[0044]
Therefore, since the molding material does not flow into the valve sleeve pin 34 and becomes clogged, the core pin 9 becomes clogged in the valve sleeve pin 34 when the molding die 2 is clamped during the molding operation. Thus, there is no possibility that the molding material 40 is bent or damaged by hitting the molding material, and the molded product 40 of stable quality can be molded.
[0045]
Further, in the injection molding apparatus 1 according to this embodiment, as shown in FIG. 7, the position of the purge piston 47 of the purge cylinder 45 is adjusted so that the core pin 9 is moved toward the inner diameter side of the valve sleeve pin 34. When inserted, a gap can be set between the tip of the core pin 9 and the valve valve center pin 36, so that the tip of the core pin 9 does not contact the tip of the valve center pin 36. Is what you can do. Therefore, the tip of the core pin 9 can be prevented from being deformed or damaged by the contact, so that the molded article 40 is scratched by the tip of the core pin 9 when the molded article 40 is released from the mold. And a stable good quality molded article 40 can be obtained.
[0046]
【The invention's effect】
As described above, according to the injection molding apparatus of the first aspect of the present invention, when the molding material is purged from the nozzle, the opening of the valve sleeve pin is closed by the valve center pin. Therefore, the molding material does not flow into the valve sleeve pin and becomes clogged. Therefore, when the core pin is inserted into the valve sleeve pin during the clamping of the molding die, the molding material does not hinder the insertion of the core pin into the valve sleeve pin. It does not cause breakage or the like, and a molded product of a constant quality can always be formed.
[0047]
According to the injection molding apparatus of the second aspect, the valve center pin is urged by the urging member when the molding material is purged from the nozzle and closes the opening of the valve sleeve pin. Therefore, the molding material does not flow into the valve sleeve pin and clog. Therefore, when the core pin is inserted into the valve sleeve pin at the time of clamping the molding die, the insertion of the core pin into the valve sleeve pin is not obstructed by the molding material, so that the core pin may be bent. It does not cause breakage or the like, and a molded product of a constant quality can always be formed.
[0048]
Further, according to the injection molding apparatus of the third aspect, the valve center pin closes the opening of the valve sleeve pin by the operation of the driving device when the molding material is purged from the nozzle. In addition, the molding material does not flow into the valve sleeve pin and becomes clogged. Therefore, when the core pin is inserted into the valve sleeve pin at the time of clamping the molding die, the insertion of the core pin into the valve sleeve pin is not obstructed by the molding material, so that the core pin may be bent. It does not cause breakage or the like, and a molded product of a constant quality can always be formed. Further, by adjusting the driving device, a gap can be formed between the tip of the valve center pin and the tip of the core pin, so that the tip of the core pin is not deformed or scratched by the contact. As a result, a stable high-quality molded product can be obtained without damaging the molded product at the tip of the core pin during release.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an entire embodiment of an injection molding apparatus according to the present invention, and is an explanatory view showing a state in which a molding die is clamped.
FIG. 2 is an explanatory view showing a state in which a molding die is opened, and is an explanatory view showing a state in which an injection hole is closed.
FIG. 3 is an explanatory view showing a state where an injection hole is opened.
FIG. 4 is a sectional view of a molded product.
FIG. 5 is a partial sectional view showing another embodiment of the injection molding apparatus according to the present invention, and is an explanatory view showing a state where a valve center pin is located at an upper end.
FIG. 6 is a partial cross-sectional view showing another embodiment of the injection molding apparatus according to the present invention, and is an explanatory view showing a state where a valve center pin is located at a lower end.
FIG. 7 is a partial cross-sectional view showing another embodiment of the injection molding apparatus according to the present invention, and is an explanatory view showing a positional relationship between a valve center pin and a core pin.
[Explanation of symbols]
Reference Signs List 1 injection molding device 2 molding die 3 movable die 9 core pin 10 fixed die 18 hot nozzle 28 valve cylinder 34 valve sleeve pin 36 valve center pin 38 biasing member 39 cavity 45 drive device (purge cylinder)

Claims (3)

A mold having a fixed mold and a movable mold that are relatively openably provided with a mold, and a mold that forms a cavity between both molds when the molds are clamped; A nozzle for injecting and filling a molding material into the cavity, a valve sleeve pin for opening and closing the nozzle so as to be movable in the vertical direction, and a valve sleeve pin for being provided on the movable mold side; An injection molding apparatus comprising: a core pin having a tip portion inserted into the valve sleeve pin at the time of clamping of a mold, wherein a valve center pin is inserted into the valve sleeve pin so as to be movable in a vertical direction; An injection molding apparatus characterized in that an opening of the valve sleeve pin is closed by the valve center pin when the molding material is purged from the apparatus. The injection molding apparatus according to claim 1, wherein the valve center pin is urged by an urging member to close an opening of the valve sleeve pin when purging molding material from a nozzle, When the mold is closed, the molding pin is pressed by the core pin, moves in the valve sleeve pin against the urging member, and allows the core pin to be inserted into the valve sleeve pin. Injection molding equipment. 2. The injection molding apparatus according to claim 1, wherein the valve center pin is movable in the valve sleeve pin by operation of a driving device, and when purging molding material from the nozzle, The operation of the driving device moves the inside of the valve sleeve pin to close the opening of the valve sleeve pin, and when the mold is closed, the operation of the driving device causes the inside of the valve sleeve pin to move. An injection molding apparatus, wherein the injection molding apparatus moves to allow insertion of the core pin into a valve sleeve pin.

Images