JPH11254487A - Valve gate type mold assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To actuate a valve pin which opens/closes a gate surely and synchronously even for a multi-cavity mold. SOLUTION: Valve pins 36 are fixed to a common valve supporting plate 37. A backing pin 43 fixed to the plate 37 is exposed to a surface facing a movable mold 2 in a fixed mold 1. The plate 37 is pushed toward the movable mold 2 by a spring 42. A driving pin supporting plate 71 which is pushed by the second ejection mechanism of an injection molding machine is installed in the movable mold 2. A driving pin 72 which pushes the backing pin 43 is fixed to the plate 71. A mold is closed with the driving pin 72 pushed toward the fixed mold 2 by an ejection mechanism. In this way, the driving pin 72 pushes the backing pin 43 to open a gate 33. After a cavity being filled with a resin, the plate 71 is released from pressing so that the valve supporting plate 37 is moved by the spring 42 to close the gate 33.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve gate type mold apparatus used for injection molding of a thermoplastic resin, and more particularly to a multi-cavity mold apparatus.

[0002]

A hot runner mold apparatus used for injection molding of a thermoplastic resin heats a resin in a material passage to a gate to a cavity and constantly melts the resin in order to increase molding efficiency. To keep. On the other hand, the resin in the cavity to be a product must be cooled and solidified. Therefore, in the hot runner mold device, it is necessary to open and close the gate by some means. As the gate opening / closing method, there are a valve gate method in which the gate is mechanically opened / closed by a valve pin, and an open gate method such as a spear system in which the resin in the gate portion is opened / closed by melting or solidifying the resin by turning on / off the heater.

In a conventional valve gate type mold apparatus, in the case of multi-cavity molding, a valve pin as a valve body for opening and closing a gate to each cavity is driven by a separate driving device such as an air cylinder or a hydraulic cylinder. I was However, when the number of picks is large, for example, 48 picks, it is difficult to make the responsiveness of all the driving devices uniform. That is, all the valve pins do not operate at the same time, and it is difficult to simultaneously control the molding conditions in all the cavities.

[0004] For this reason, conventionally, when the number of products is large, an open gate system such as a spear system has been adopted.
With an open gate system that opens and closes gates by turning on and off heaters, it is easy to synchronize the timing of opening and closing all gates. However, spear systems are expensive, and having to use many of them increases costs. Further, in the open gate method, it is inevitable that the resin slightly drips out of the gate (resin dripping) in the mold open state, and it is necessary to remove this. On the other hand, in the case of the valve gate method, resin dripping does not occur, and cleaning can be performed only by blowing air.

The present invention is intended to solve such a problem. Even when the number of valves is large, a valve gate for opening and closing a gate to each cavity can be reliably operated in a synchronized manner. It is an object of the present invention to provide a mold apparatus.

[0006]

SUMMARY OF THE INVENTION In order to achieve the above object, a valve gate type mold apparatus according to the present invention has a fixed mold and a movable mold which open and close with each other and form a plurality of cavities therebetween when the mold is closed. A mold, wherein the fixed mold has a material passage and a gate that opens to each of the cavities from the material passage, and a plurality of valve bodies that move in the opening and closing directions of the fixed mold and the movable mold to open and close the gates, respectively. A valve support body to which the plurality of valve bodies are commonly connected is provided on the fixed mold so as to be movable in the opening and closing direction, and the valve support body is attached to the movable mold side by biasing means. The valve support is provided integrally with a receiving body extending to the movable mold side, and the movable mold is pressed against the stationary mold-side receiving body against the urging of the urging means. To provide a driving body Than it is.

During molding, when the fixed mold and the movable mold are closed, the movable body-side driving body presses the fixed mold-side receiving body, and the valve support is movable against the urging of the urging means. Moves with the mold. Each valve body also moves integrally with the valve support, and each gate is opened. Thereby, in the fixed mold, the molding material is filled into each cavity from each gate through the material passage. After this filling, at an appropriate timing,
The pressing of the receiving body by the driving body is released. Along with this, the urging of the urging means moves the valve support and each valve body in a direction approaching the movable type, and each valve body closes each gate. Further, after the molding material in the cavity, that is, the product is solidified, the fixed mold and the movable mold are opened, and the molded product is taken out.

According to a second aspect of the present invention, in the valve gate type mold apparatus according to the first aspect of the present invention, the driving body is driven by being pressed by a protruding body provided on a molding machine to which a movable die is attached. Things.

That is, the projecting body of the molding machine presses the driving body toward the fixed mold, so that the driving body can press the fixed receiving body when the mold is closed. When the pushing of the driving body by the protruding body is released, the pressing of the receiving body by the driving body is also released.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a valve gate type mold apparatus according to the present invention will be described below with reference to FIGS. The mold apparatus includes a fixed mold 1 and a movable mold 2 which move in the left and right directions in the figure to open and close, and a plurality of product-shaped cavities 3 are provided between the fixed mold 1 and the movable mold 2 when the mold is closed. To form.

The fixed die 1 on the right side of the drawing has a fixed mounting plate 11 attached to a fixed platen of an injection molding machine (not shown), and a left mounting plate (a movable die 2) of the fixed mounting plate 11.
Side) a first spacer block 12 fixed to a peripheral portion;
An intermediate plate 13 fixed to the left side of the first spacer block 12 in the drawing, a second spacer block 14 fixed to the left side peripheral portion of the intermediate plate 13, and a left side of the second spacer block 14 in the drawing And a fixed-side mold plate 15 fixed to the base plate.

A sprue bush 21 and a locate ring 22 connected to a nozzle of an injection molding machine are fixed to the fixed side mounting plate 11. The sprue bush 21 has therein a sprue 23 which is a material passage into which a molten thermoplastic resin as a molding material injected from a nozzle of an injection molding machine flows. A manifold 26 is provided between the intermediate plate 13 and the fixed mold plate 15. The tip of the sprue bush 21 penetrating the intermediate plate 13 is connected to the manifold 26. And the manifold
A runner 27 is formed inside 26 as a material passage communicating with the sprue 23. This runner 27
The material passage is branched into a plurality of cavities 3, respectively. Further, a plurality of valve casings 31 respectively corresponding to these cavities 3 are provided with manifolds 26.
It is connected to the. These valve casings 31 are embedded and fixed in the fixed side mold plate 15, but the inside is a material passage 32 communicating with a branch passage of the runner 27, and this material passage 32 is opened to the cavity 3. Gate
33 is provided at the tip. And, although not shown,
The sprue bush 21, the manifold 26, and the valve casing 31 are provided with heaters, respectively, and the heating of the heaters keeps the resin in the sprue 23, the runner 27, and the material passage 32 in a molten state at all times. ing.

Each of the gates 33 is opened and closed by a valve pin 36 as a valve body which moves in the horizontal direction in the figure, ie, in the mold opening and closing directions of the fixed mold 1 and the movable mold 2. In order to drive these valve pins 36, a valve support plate 37 as a valve support is supported between the fixed mounting plate 11 and the intermediate plate 13 so as to be movable in a predetermined range in the mold opening and closing direction. This support is achieved, for example, because a guide pin 38 fixed to the intermediate plate 13 slidably penetrates a slide bearing 39 assembled to the valve support plate 37. All of the plurality of valve pins 36 are commonly fixed to the valve support plate 37 at the base end thereof. The valve pins 36 penetrate through the through holes 40 and 41 in the mold opening / closing direction formed in the intermediate plate 13 and the manifold 26, respectively, and the tip ends thereof are located in the valve casing 31. Further, the valve support plate 38 is provided with a spring as urging means mounted between the valve support plate 38 and the fixed-side mounting plate 11.
It is constantly urged toward the movable mold 2 by 42. The base end of a receiving pin 42 as a receiving body is also fixed to the valve support plate 37. The receiving pin 42 is provided on the intermediate plate 13,
The distal end is exposed through the through holes 44, 45, 46 in the mold opening / closing direction formed in the manifold 26 and the fixed mold plate 15, respectively, and the tip is exposed on the surface of the fixed mold plate 15 facing the movable mold 2. . The sprue bush 21 is provided on the valve support plate 37.
Through the through hole 47 formed in the through hole.

The movable mold 2 includes a movable mounting plate 51 mounted on a movable platen of an injection molding machine, and a first fixed to a peripheral portion of the movable mounting plate 51 on the right side (fixed mold 1 side) in the drawing.
Spacer block 52 and the first spacer block
52, an intermediate plate 53 fixed to the right side of the drawing, and a second spacer block 54 fixed to the right peripheral portion of the intermediate plate 53 in the drawing.
And a movable mold plate 55 fixed to the right side of the second spacer block 54 in the drawing. This movable side mold plate 55
Is for forming the cavity 3 between the fixed side mold plate 15 and the fixed side mold plate 15.

Between the movable mold plate 55 and the intermediate plate 53,
A protruding plate 61 is supported movably within a predetermined range in the mold opening and closing direction of the fixed mold 1 and the movable mold 2. The protruding plate 61 has base ends of a plurality of protruding pins 62 fixed thereto. These protruding pins 62 slidably penetrate the movable mold plate 55, and their tip portions are located facing the respective cavities 3. A projecting rod receiver 63 is provided on the surface of the projecting plate 61 on the side opposite to the fixed mold 1.
Has been fixed. The protruding rod receiver 63 penetrates through the through holes 64 and 65 in the mold opening and closing direction formed in the intermediate plate 53 and the movable-side mounting plate 51, respectively. Then, the ejection pin 62 is pressed by the first ejection rod 66 of the first ejection mechanism provided in the injection molding machine, and the ejection pin 62 is fixed.
It moves to the direction of. The first protruding rod 66 is driven by a hydraulic cylinder 67.

A drive pin support plate 71 is supported between the movable mounting plate 51 and the intermediate plate 53 so as to be movable within a predetermined range in the mold opening and closing direction. Then, the drive pin support plate 71
, The base end of a driving pin 72 as a driving body is fixed. The drive pin 72 is connected to the intermediate plate 53, the projecting plate 61
And the front end thereof is exposed to the surface of the movable mold plate 55 on the fixed mold 1 side through the through holes 73, 74, 75 in the mold opening / closing direction formed on the movable mold plate 55, respectively. It is coaxially opposed to the receiving pin 43 on the mold 1 side. A protruding rod receiver 76 is fixed to a surface of the drive pin support plate 71 on the side opposite to the fixed die 1. This protruding rod receiver 76
Is a through hole in the mold opening and closing direction formed in the movable side mounting plate 51.
It penetrates 77. Then, the protrusion rod receiver 76 is pressed by a second protrusion rod 78 as a protrusion of a second protrusion mechanism provided in the injection molding machine, and the drive pin support plate 71 and the drive pin 72 are moved toward the fixed mold 1. The driving pin 72 presses the receiving pin 43 against the bias of the spring 42 to open the valve pin 36. The second protruding rod 78 is driven by a hydraulic cylinder 79. The projecting rod receiver 63 of the projecting plate 61 passes through a through hole 80 formed in the drive pin support plate 71.

Next, the operation of the above configuration will be described. FIG. 1 shows a state where the fixed mold 1 and the movable mold 2 are opened. In this mold open state, the valve support plate 37 is positioned at the movable limit of the movable mold 2 side in the fixed mold 1 by the bias of the spring 42. In this state, the respective valve pins 36 fixed to the common valve support plate 37 are fitted to the respective gates 33 to close the gates 33. And
Prior to closing the mold, as shown in FIG.
The second pushing rod 78 of the pushing mechanism pushes the drive pin support plate 71 through the pushing rod receiver 76. The drive pin 72 moves toward the fixed mold 1 together with the drive pin support plate 71.

Thereafter, the fixed mold 1 and the movable mold 2 are closed as shown in FIG. At the last stage of closing the mold, the driving pin 72, which has been moved to the fixed mold 1 side by the driving of the second ejection mechanism of the injection molding machine as described above, causes the receiving pin 43 on the fixed mold 1 side to be connected to the spring 42. , And the receiving pin 43 moves integrally with the movable mold 2. As a result, in the fixed die 1, the receiving pin 43 relatively moves to the side opposite to the movable die 2. The valve support plate 37 and the valve pin 36 also move integrally with the receiving pin 43, thereby
The tip of each valve pin 36 comes out of each gate 33 at the same time, and these gates 33 are opened. Immediately after the gate 33 is opened, the injection of the resin from the injection molding machine starts. Thereby, the resin in the sprue 23, the runner 27 and the material passage 32 of the fixed mold 1 flows toward the cavity 3. Thereby, the resin flows into the cavity 3 from the material passage 32 through the gate 33. Even after the cavity 3 is filled with the resin in this way, the pressure of the resin on the fixed mold 1 is slightly continued on the nozzle side of the injection molding machine (pressure holding). This holding pressure is for preventing the resin from flowing backward from the cavity 3 and for compensating the resin for the shrinkage due to the cooling of the resin.

At the end of the holding pressure, the second ejecting rod 78 of the second ejecting mechanism of the injection molding machine retreats and separates from the ejecting rod receiver 76. When the pressing of the drive pin support plate 71 by the second protruding mechanism is released in this way, the press of the drive pin 72 fixed to the drive pin support plate 71 on the receiving pin 43 is also released. Accordingly, as shown in FIG. 3, the bias of the spring 42 causes the valve support plate 37 and the valve pin 36 of the fixed mold 1 to move closer to the movable mold 2. As a result, the tip of each valve pin 36 is fitted into each gate 33, and these gates 33 are closed. In addition, with the movement of the valve support plate 37 at that time, the drive pin 72 and the drive pin support plate 71 on the movable mold 2 side are also moved by being pushed by the receiving pin 43.

The timing at which the second protruding rod 78 is retracted can be freely set by setting a timer.

Further, after the resin in the cavity 3, that is, the product P is sufficiently cooled and solidified, as shown in FIG.
The fixed mold 1 and the movable mold 2 are opened. With this mold opening,
The molded product P first leaves the fixed mold 1. The first ejection rod 66 of the first ejection mechanism of the injection molding machine pushes the ejection plate 61 via the ejection rod receiver 63. As a result, the projecting pin 62 is
Moves to the fixed mold 1 and projects the product P to move the movable mold 2.
Release from mold. After the product P released in this way is taken out by a take-out device (not shown), the mold is closed again as described above, and the molding is repeated.

According to the configuration of the above embodiment, the plurality of valve pins 36 are fixed to the common valve pin support plate 37 and driven via this valve pin support plate 37, so that all the valve pins 36 are completely synchronized. Can be operated. Therefore, the molding conditions can be reliably and simultaneously controlled in all the cavities 3, and good molding can be performed. This is particularly advantageous when the number of picks is large, for example, 16 or more.

Further, the valve pin support plate 37 is provided with a receiving pin.
The valve is driven by the drive pin 72 provided on the movable mold 2 side via 43, so that the valve pins can be opened in conjunction with the mold closing reliably, and the response of all the valve pins is good. Can be. Therefore, the timing for opening the valve pin 36 can be made appropriate, and molding defects due to the valve pin opening too early and an increase in molding cycle time due to the valve pin opening slowly can be prevented.

Further, some injection molding machines are provided with two systems of ejection mechanisms which operate independently for two-stage ejection, etc. In the above embodiment, two ejection mechanisms provided in the injection molding machine are used. Since the drive pin 72 is driven using one of the two, the drive source for driving the drive pin 72 does not need to be incorporated into the mold device itself, and the structure of the mold device can be simplified, The mold can be easily manufactured and the cost can be reduced.

Next, a second embodiment of the valve gate type mold apparatus of the present invention will be described with reference to FIG.
The structure of the fixed mold 1 side of the second embodiment is the same as that of the first embodiment. In the second embodiment, the movable die 2 is provided with a drive source for the drive pin 72 on the movable die 2 for driving the receiving pin 43 on the fixed die 1. This drive source is a hydraulic cylinder
A drive pin 72 is provided integrally with a piston 82 that moves in the mold opening and closing direction of the hydraulic cylinder 81. The timing at which the drive pin 72 presses the receiving pin 43 is exactly the same as in the first embodiment.

According to the configuration of the second embodiment, the valve pin 36 can be driven only by the mold apparatus, and the present invention can be carried out by an injection molding machine having no two-projecting mechanism.

The present invention is not limited to the above-described embodiment, and various modifications can be made. For example,
The present invention can be favorably applied to a stack mold apparatus.

[0028]

According to the first aspect of the present invention, in a multi-cavity valve gate type mold apparatus, a plurality of valve bodies for respectively opening and closing gates to respective cavities are commonly connected to a fixed mold. The support is provided so as to be movable in the opening and closing directions of the fixed type and the movable type, and the valve support is urged toward the movable type by an urging means.
A receiving body extending to the movable mold side is provided integrally,
Since a driving body that presses the fixed-side receiving body against the urging force of the urging means is provided, even when the number of cavities is large, all the valve bodies can be reliably operated in synchronization with each other. The molding conditions can be reliably controlled at the same time in the cavity, and good molding can be performed. In addition, since the valve body opens in conjunction with the closing of the mold, the timing can be made appropriate.

According to the valve gate type mold apparatus of the second aspect of the present invention, in addition to the effect of the first aspect of the present invention, the driving body is formed by a protruding body provided on a molding machine to which a movable mold is attached. Since it is pressed and driven, there is no need to incorporate a driving source for driving the driving body into the mold device itself,
The structure of the mold device can be simplified, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a valve gate type mold apparatus according to the present invention, showing a state when a mold is opened.

FIG. 2 is a cross-sectional view showing a state where a gate is opened when the mold is closed.

FIG. 3 is a cross-sectional view showing a state in which a gate is closed when the mold is closed.

FIG. 4 is a sectional view showing a second embodiment of the valve gate type mold apparatus of the present invention.

[Explanation of symbols]

 Reference Signs List 1 fixed type 2 movable type 3 cavity 23 sprue (material passage) 27 runner (material passage) 32 material passage 33 gate 36 valve pin (valve body) 37 valve support plate (valve support) 42 spring (biasing means) 43 receiving pin (Receiver) 72 Drive pin (Driver) 78 Second protruding rod (Protruder)

Claims (2)

[Claims] 1. A fixed mold and a movable mold which are opened and closed with each other and form a plurality of cavities therebetween when a mold is closed, wherein the fixed mold has a material passage and a gate which is opened from the material passage to each of the cavities, A plurality of valve bodies that move in the opening and closing directions of the fixed and movable molds to open and close the respective gates, and the fixed mold includes a valve support in which the plurality of valve bodies are connected in common. Along with being movably provided in the opening and closing direction, the valve support is urged toward the movable mold side by urging means, and the valve support is integrally provided with a receiving body extending toward the movable mold side,
A valve gate type mold apparatus, wherein the movable die is provided with a driving body that presses the receiving body on the fixed die side against the urging of the urging means. 2. The valve gate type mold apparatus according to claim 1, wherein the driving body is driven by being pressed by a protruding body provided in a molding machine to which a movable die is attached.