JP2870630B2 - Molding equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve opening / closing type molding apparatus.

[0002]

Are subjected to a piston having one end connected BACKGROUND ART valve pin to reciprocally accommodated an injection molding device widely used for valve opening and closing with a cylinder of the cavity
Japanese Patent Publication No. 3-54611 discloses a configuration in which a cylinder is provided for each of the gates . And
Some molding apparatuses include a plurality of cavities and mold a plurality of products in one molding cycle.

A conventional molding apparatus of this kind has been proposed, for example, in Japanese Utility Model Publication No. 50-10465. As shown in FIG. 2, the molding apparatus includes molds 1 and 2 having a plurality of cavities C, C, and a hot runner block 3 for supplying a molten resin filled into each of the cavities C, C. A plurality of nozzles 4, 4 for supplying and blocking the molten resin from the hot runner block 3 to the cavities C, C, and a plurality of valve opening and closing devices 5, 5 for opening and closing the respective nozzles 4, 4; And a plasticizer 6 for plasticizing the raw material and feeding the molten resin to the hot runner block 3.

The nozzle 4 is integrated with the hot runner block 3 to constitute a hot runner device. The nozzle body 4a is brought into contact with the mold 2, and the nozzle 4 is slidably mounted in the nozzle body 4a. And a valve pin 4b that opens and closes the tip of the nozzle body 4a (the portion in contact with the mold) from inside. Further, the valve opening / closing device 5 is constituted by a hydraulic cylinder, and is fixed to the hot runner block 3, and a valve pin 4b penetrating the hot runner block 3 and protruding to the outside is fixed to the piston 5a. ing.

[0005] In the conventional molding apparatus configured as described above, the resin plasticized by the plasticizing apparatus 6 is filled with the hot runner block 3 and the cavities C, C in the molds 1, 2. Filling is performed through the resin passage 7 in the nozzle bodies 4a, 4a. Before the filling, the valve opening / closing devices 5, 5 are operated, and the valve pins 4b, 4b open the tip portions of the nozzle bodies 4a, 4a. So retreat,
The resin passage 7 is opened. After filling, the nozzles 4, 4 are closed again by the valve opening / closing devices 5, 5, and the nozzles 4, 4
Prevent resin from flowing out. In the drawing, reference numeral 8 denotes a fixed plate of a mold clamping mechanism (not shown) for opening and closing the dies 1 and 2, and the fixed plate 8 has holes 8a and 8a for passing the nozzles 4 and 4, respectively. Is formed.

[0006]

However, such a conventional molding apparatus has the following problems to be improved. That is, since one hydraulic cylinder has to be installed for one nozzle 4, the installation position of the nozzle 4 is limited by the pitch at which the nozzle opening and closing device 5 can be installed.
In a so-called multi-cavity mold in which one cavity C is formed for one nozzle 4, the cavity C
Processing position is restricted. In particular, when the product dimension is smaller than the pitch at which the nozzles 4 can be installed, the cavity C cannot be formed even though the space for forming the cavity C exists, and the workable area of the mold cannot be effectively used. Becomes

The opening and closing of a plurality of nozzles 4 and 4 are performed by valve opening and closing devices 5 and 5 provided respectively. The hydraulic oil supplied to these valve opening and closing devices 5 and 5 is a single hydraulic oil. Since it is generated and supplied by the hydraulic pressure generation source, there is a problem that the supply of the hydraulic oil to each of the valve opening and closing devices 5 and 5 tends to be uneven. When such a problem occurs, the opening / closing timing of each of the nozzles 4 and 4 is deviated, so that the amount of the molten resin charged into each of the cavities C and C and the pressure of the filled resin are reduced. And the molding accuracy is reduced. Further, since the valve opening / closing device 5 must be provided for each nozzle 4, the cost of mold production including the installation of the apparatus main body, piping, signal lines, and the like increases.
In addition, the installation of such a large number of pipes and signal lines necessitates replacement work at the time of mold replacement, which also complicates the setup replacement work.

In view of the foregoing, an object of the present invention is to enable the operation of a plurality of nozzles to be reliably synchronized with a simple configuration, thereby suppressing the limitation of the die machining area due to the opening and closing device for the nozzles. It is an object of the present invention to provide a molding apparatus in which a replacement operation is simplified.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a hot runner block for supplying a molten resin filled in a cavity formed by a pair of dies, A nozzle provided in a communicating portion between the runner block and the cavity, for supplying and blocking the molten resin to the cavity, and a valve pin for opening and closing the nozzle by reciprocating a valve pin constituting the nozzle. A molding apparatus comprising: an apparatus; and a mold clamping mechanism for opening and closing the mold, wherein the valve opening and closing apparatus is provided on a movable member to which each of the valve pins is connected, and on a fixed platen of the mold clamping mechanism. And a driving means for moving the movable member in the opening and closing direction of the nozzle.

[0010] Further, the invention according to claim 2 is based on claim 1.
In the invention described above, a plurality of the nozzles are provided, and a plurality of the valve pins are connected to the movable member.

[0011]

According to the first aspect of the present invention, the movable member is moved by the driving means provided on the fixed plate of the mold clamping mechanism, so that the valve pin connected to the movable member is opened and closed.

According to the second aspect of the present invention, since each of the valve pins is rigidly connected via the movable member, each of the valve pins is integrally moved, thereby synchronizing all of the valve pins. Is surely taken.
In addition, since the driving means is connected to each valve pin via the movable member, the driving means can be installed irrespective of the installation position of the valve pin, thereby eliminating the restriction on the processing area of the mold. Furthermore, since the drive means only moves the movable member, the number of installations can be suppressed to a minimum and installation on a fixed plate outside the mold becomes possible, so that maintenance and setup replacement work are simple. Becomes

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a molding apparatus according to the present invention will be described below with reference to FIG. First, as shown in FIG. 1, the molding apparatus 10 includes a pair of dies 1 and 2,
A hot runner block 3 for supplying molten resin to be filled into a plurality of cavities C formed between the two, and a plurality of nozzles 11 provided in the hot runner block 3
And a valve opening / closing device 13 for reciprocating the valve pin 11b. The valve opening / closing device 13 is provided on a movable member 14 having a plurality of valve pins 11b and the fixed plate 9 of the mold clamping mechanism.
And a driving means 15 for moving the motor 4. In FIG. L is a parting line for the dies 1 and 2.

That is, the hot runner block 3 is a fixed platen 9 of a mold clamping mechanism (not shown) for opening and closing the molds 1 and 2.
The hot runner block 3 is provided in correspondence with each cavity C and has a valve pin 11b.
And a plurality of nozzle bodies 11a constituting the nozzle 11
Has been fixed. And each of these nozzle bodies 11
a and the hot runner block 3
And a resin passage 7 serving as a supply passage of the molten resin is formed continuously. The hot runner block 3 and the nozzle 11 are heated by a heater (not shown) or the like so that the molten resin does not solidify. The fixed platen 9 has a hole 9 a for connecting the nozzle portion at the tip of the plasticizing device 6 to the resin passage 7 of the hot runner block 3.

The connecting block 12 fixes the mold 2 and the hot runner block 3 to the fixed platen 9. The connecting block 12 has a space 12 a in which the hot runner block 3 and the nozzle 11 are arranged. As described above, a gap 12b is formed between the block 3 and the fixed board 9 to hold them at a position separated by a predetermined distance. The gap 12b is made to communicate outward from the side of the fixed board 9. And this gap 12
In b, while joining the plate 16 to the fixed platen 9,
A plate 17 is also joined to the connection block 12 and the hot runner block 3 with a heat shield plate 18 interposed therebetween. further,
On the side opposite to the gap 12b, a heat shield plate 19 is interposed between the hot runner block 3 and the connection block 12.

On the other hand, the movable member 14 is formed in a plate shape in the embodiment, and is disposed between the plates 16 and 17 in the gap 12b between the fixed board 9 and the hot runner block 3, and a part of the movable member 14 is formed in the gap 12b. Is drawn out of the hot runner block 3 and is opposed to the plate 16 joined to the fixed platen 9 outside the hot runner block 3. The valve pins 11b fixed to the movable member 14 penetrate the hot runner block 3, the heat shield plates 18 and the plates 17, and project toward the plate 16 of the fixed plate 9. The radial end portion is fixed to the movable member 14 by an appropriate connecting means, for example, by screwing or engaging using a collet. Note that the movable member 14 may be two plates, and the large-diameter end of the valve pin 11b may be sandwiched and fixed between the two plates.

In the embodiment, a fluid pressure cylinder is used as the driving means 15, and its cylinder body 15a
Is fixed to the fixed plate 9, and one end of the piston rod 15 b is fixed to a portion that penetrates the hole 9 b of the fixed plate 9 and protrudes laterally from the gap 12 b of the movable member 14. . When the movable member 14 is moved, the driving means 15 must be moved in parallel with the fixed platen 9. Therefore, it is preferable that the driving means 15 be provided at both ends of the movable member 14. If it can be moved, it may be one.

Further, the piston rod 1 of the driving means 15
The other end of 5b protrudes from the cylinder body 15a, and a pair of limit switches 20 and 21 are installed at a position facing the other end of the piston rod 15b. These limit switches 20 and 21 are configured by proximity switches or the like, and
To the piston rod 15b
By detecting the position of the piston rod 15b in cooperation with the other end of the movable member 14, the most advanced position and the most retreated position of the movable member 14 are detected. I have.

Next, the operation of the molding apparatus 10 of the embodiment configured as described above will be described. By moving the movable member 14 toward the fixed platen 9 by the driving means 15, each valve pin 11b is retracted, and the nozzle body 1 is moved.
Open the tip of 1a. Prior to the main molding, several times of blanking are performed to fill the resin passage 7 with the molten resin.
Next, after clamping both the dies 1 and 2, the nozzle body 1
Each of the cavities C is filled from the tip of 1a and molded. After the filling, the movable member 14 is moved toward the hot runner block 3 by the driving means 15 so that each valve pin 11b is advanced, and the nozzle body 1 is moved.
The tip of 1 a is closed to prevent the resin from flowing out of the nozzle 11.

At the time of such a molding operation, all the valve pins 11b are integrally moved by the rigid connection of each valve pin 11b via the movable member 14. In addition, the movement of each valve pin 11b is guided by the nozzle body 11a, and the movement in the oblique direction with respect to the center line thereof is restrained.
The movement of b is substantially linear and the steady rest is performed. Accordingly, the movements of the respective valve pins 11b are performed in synchronization with each other, so that the opening and closing timings of the respective nozzles 11 are prevented from shifting, and accordingly, the variation in the amount of resin charged into each of the plurality of cavities C is suppressed. This improves the molding accuracy.

The movable member 14 to which the valve pin 11b is fixed has a function of merely connecting the valve pins 11b to each other, and does not limit the interval between the valve pins 11b. 1
A driving means 15 for opening and closing 1b is connected to each of these valve pins 11b via a movable member 14,
And since it is installed in a position largely separated from the side portions of the dies 1 and 2, the interference of the valve opening / closing device 13 with the installation position of the valve pin 11b is eliminated. Therefore, the limitation on the formation pitch of the cavity C is reduced, and effective use of the workable area of the mold is achieved. Further, the driving means 1
5 is located at the position of the fixing plate 9 exposed from the molding device 10, and the number of installations is suppressed to a minimum, so that the maintenance is easy and the changeover work is also simplified.

The various shapes, dimensions, and the like of each component shown in the above-described embodiment are merely examples, and can be variously changed based on design requirements and the like. For example, in the embodiment, the example in which the limit switches 20 and 21 are used to control the operation position of the valve pin 11b has been described, but instead, the surface of the hot runner block 3 or the fixed plate 9 facing the movable member 14 is used. The movable member 14 is brought into contact with these position regulating members, and the movable member 14 is moved forward or backward, that is, the forward or backward position of the valve pin 11b is regulated. It may be. Further, in the embodiment, the molding apparatus provided with one cavity C for one nozzle 11 has been illustrated. However, the same applies to a molding apparatus in which a plurality of nozzles 11 are provided for one cavity C. Applicable. Further, it goes without saying that the present invention can be applied to a molding device having one nozzle.

[0023]

As described above, according to the molding apparatus of the first aspect, the movable member is moved by the driving means provided on the fixed plate of the mold clamping mechanism, and the valve pin connected to the movable member is moved. Can be opened and closed. Therefore,
In the case of a molding device having a plurality of nozzles, the operations of the plurality of nozzles can be reliably synchronized with a simple configuration.

According to the molding apparatus according to the second aspect of the present invention, a plurality of valve pins are rigidly connected to each other via a movable member, so that the movement of each valve pin during the molding operation is integrated. Operation of the valve pins can be completely synchronized. Thereby, it is possible to eliminate the time lag of the operation of each nozzle, perform the molding closer to the planned value, and improve the molding accuracy. In addition, by connecting the driving means and each valve pin via the movable member, it becomes possible to install the driving means irrespective of the installation position of each valve pin, thereby reducing the workable area of the mold. It is possible to suppress and effectively use the workable area. further,
The function of the driving means is centralized in the operation of moving the movable member, and the number of installations can be suppressed to the minimum, and the limitation of the installation position described above can be eliminated. Not only can the configuration be simplified, but also the maintenance and setup replacement work can be simplified.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a main part showing an embodiment of a molding apparatus of the present invention.

FIG. 2 is a longitudinal sectional view of a main part showing a conventional molding apparatus.

[Explanation of symbols]

 Reference Signs List 1, 2 Mold 3 Hot runner block 6 Plasticizer 7 Resin passage 9 Fixing plate 10 Molding device 11 Nozzle 11a Nozzle body 11b Valve pin 12 Connection block 13 Valve opening / closing device 14 Movable member 15 Driving means 16,17 Plate 18,19 Hot plate 20, 21 Limit switch

Continuation of the front page (56) References JP-A-5-345334 (JP, A) JP-A-5-261780 (JP, A) JP-A-63-109031 (JP, A) JP-A-61-268421 (JP) JP-A-4-164618 (JP, A) JP-A-8-156033 (JP, A) JP-A-4-169215 (JP, A) JP-A-5-8256 (JP, A) 63-108719 (JP, U) JP 3-54611 (JP, B2) JP 42-17575 (JP, B1) Jikken 50-10465 (JP, Y1) (58) Fields surveyed (Int. Cl. ⁶ , DB name) B29C 45/00-45/84

Claims (2)

(57) [Claims] 1. A hot runner block for supplying a molten resin to be filled into a cavity formed by a pair of molds, and a hot runner block is provided at a communicating portion between the hot runner block and the cavity, and the molten resin is supplied to the cavity. Forming and closing the nozzle by opening and closing the nozzle by reciprocating a valve pin constituting the nozzle, and a mold clamping mechanism for opening and closing the mold of the mold The valve opening / closing device is configured by a movable member to which the valve pin is connected, and a driving unit provided on a fixed plate of the mold clamping mechanism and moving the movable member in the opening / closing direction of the nozzle. Forming apparatus. 2. The molding apparatus according to claim 1, wherein a plurality of the nozzles are provided, and a plurality of the valve pins are connected to the movable member.