JP3763768B2 - Injection molding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an injection molding machine, and more particularly to an injection molding machine using a mold having a cassette type configuration.
[0002]
[Prior art]
As an example of a conventional injection molding machine, a plunger injection type structure is shown in FIG. The basic configuration is a combination of a mold clamping mechanism and an injection mechanism, and there are inline screw type and pre-plunger type injection parts. In addition to the direct pressure method shown in FIG.
[0003]
In FIG. 11, a horizontal forming machine is shown, but there is also a vertical system that stands up as a whole.
[0004]
In the rotary table system, which has a mechanism for rotating the movable platen to which the movable mold is mounted, using the vertical method, the workability of taking out the molded product and inserting the inserted product is improved by rotating the table after molding. be able to.
[0005]
Also, if a plurality of movable side molds are prepared, it is possible to work with the other movable side mold that is vacant during molding of one side, and it is possible to increase the molding work efficiency.
[0006]
Further, there is a mechanism provided with a mechanism for sliding the movable mold back and forth.
[0007]
FIG. 12 shows a typical configuration of a conventional three-plate mold. FIG. 13 is a view showing a state in which the three-plate mold is opened.
[0008]
In the molding machine shown in FIG. 11, the injection unit portion is moved in the direction of the mold clamping unit by the injection unit moving cylinder 46, and the nozzle 52 is pressed against the mold spool bush 68 with a pressure that does not cause resin leakage during injection. The resin material is put into the hopper 1 and fed into the injection cylinder 50. The portion of the injection cylinder 50 is heated by the band heater 51 to a temperature suitable for the resin material. The plunger 48 connected by the hydraulic cylinder 45 for injection moves forward in the nozzle direction, the resin material is melted at the toe beat 49 portion, and further injected into the spool bush 68 via the nozzle portion 52. Is done. In the mold, a fixed side mounting plate 58 is fixed to the molding machine fixed side platen 54 with a bolt or the like, and a movable side mounting plate 62 is fixed to the movable side platen 55 with a bolt or the like. The movable side platen 55 is connected to a mold clamping hydraulic cylinder 56, and the mold is opened and closed by moving the movable side platen 55 guided by the tie bar 57 as the cylinder 56 moves forward and backward. At the time of injection, the mold is clamped with a predetermined force that does not open the mold by the hydraulic cylinder 56 for mold clamping. After the injection cooling, the mold is opened and the molded product 66 is discharged out of the mold by the ejector pin 65. In the figure, 53 is a band heater, 60 is a movable side template, 61 is a receiving plate, and 63 is a spacer block.
[0009]
FIG. 12 is a view showing a conventional three-plate type. This three-plate mold includes a locating ring 69 that fits a positioning hole formed in the molding machine fixed side platen 54, a fixed side mounting plate 58 for mounting the mold on the fixed side platen, and a mold on the movable side platen 55. A movable side mounting plate 62 for mounting a mold, and a spool bush 68 in which a molding machine nozzle 52 is pressed to form a resin flow path are provided. Molten resin injected from the nozzle 52 is formed in the spool bush 68. The runner 67b formed on the stationary side template 59 from the next spool 67a and the gate from the secondary spool 67c are injected into the cavity 66. The runner 67b is provided with a runner lock pin 70 for holding the spool runner on the surface of the stripper plate 71 when the gate portion is cut. In the figure, 59 is a stationary side template and 64 is an ejector plate.
[0010]
FIG. 13 shows a state where the mold shown in FIG. 12 is fully opened. The parting surface of the runner 67b portion is first opened by the action of the spring 72, and at that time, the gate portion (the tip portion of the secondary spool 67c) is cut. Next, the parting surface on which the molded product 66a is molded is opened. Finally, the stripper plate 71 is opened, and the runner lock pin 70 is removed from the runner 67b and can be taken out.
[0011]
[Problems to be solved by the invention]
The conventional molding machine is basically the same configuration as the ultra-small machine with a clamping force of several tons and the ultra-large machine with a clamping force of several thousand tons. A mechanism for moving the injection unit forward and backward and touching the spool bush 68 of the mold is necessary, and of course, a space for forward and backward movement is also required. Moreover, the piping for moving is also complicated. Further, an alignment mechanism for the nozzle 52 and the spool bush 68 is also required.
[0012]
In addition, since the injection cylinder enters the fixed side platen 54 and a hole is necessary to insert the locate ring 69 for aligning the mold, it is necessary to make a large hole in the fixed side platen 54. This is a cause of greatly reducing the rigidity of the side platen 54.
[0013]
Further, the rotary table type saddle type method for rotating the movable platen 55 requires a mechanism for rotating the table in addition to the mold clamping mechanism, so that the mechanism is complicated and the apparatus becomes large.
[0014]
Further, a general mold mounting method is such that a mold locating ring 69 is fitted into a hole formed in a fixed side platen 54 of the molding machine, and the mold fixed side mounting plate 58 is fixed to the fixed side of the molding machine. A method of fixing to the platen 54 with a bolt or the like is often used. Similarly, the movable side mounting plate 62 of the mold is fixed to the movable side platen 55 of the molding machine with bolts or the like. At this time, it is necessary to adjust the settings of the molding machine such as the thickness of the mold, the amount of mold opening, and the amount of ejector. Also, it took time to fix the bolts, and it was difficult to reduce the setup time.
[0015]
In order to solve the above problems, a cassette mold is also used, but it is a method of attaching a holder for fixing the cassette mold to the platen of a general molding machine, and the mold is placed inside the molding machine tie bar. There is a problem that it is necessary to attach a holder, and there is a problem that only a cassette type smaller than the size of the molding machine can be attached, and a mold holder is also expensive.
[0016]
Further, the three-plate mold requires a lock mechanism for the spool runner 67, complicates the mold structure, and requires parts such as a stripper plate 71, a runner lock pin 70, and a hairpin. Therefore, there is a problem that the mold becomes expensive and the size becomes large.
[0017]
At present, the molding machine and the mold are treated as different ones, and there are various wastes structurally. In addition, the structure is the same regardless of the size of the molding machine, and there is no structural device adapted to the size of the molding machine.
[0018]
Accordingly, the present invention has been made in view of the above-described problems, and an object of the present invention is to provide an injection molding machine that can reduce useless mechanisms and achieve downsizing and cost reduction.
[0019]
[Means for Solving the Problems]
In order to solve the above-described problems and achieve the object, an injection molding machine according to the present invention includes an injection mechanism part that melts and injects a resin, and a mold clamping mechanism part to which a mold is attached. The mold clamping mechanism includes a stationary platen, a stationary mold plate holder for mounting the stationary mold plate of the mold, and a movable mold plate holder as a movable platen for mounting the movable mold plate of the mold; The injection mechanism portion has an injection cylinder, the injection cylinder is attached to a jacket supported by a block connected to the stationary platen, and the tip of the injection cylinder is in contact with the spool portion of the mold. A nozzle for pouring the molten resin is attached, the tip of the nozzle is fitted into a hole provided in the stationary platen, and the injection cylinder is It is characterized in that mounted in a form that can not be moved relative to Jogawa platen.
[0020]
In the injection molding machine according to the present invention, the number of the blocks is two .
[0021]
In the injection molding machine according to the present invention, the heating cylinder is attached to the jacket with a heat insulating plate interposed therebetween .
[0029]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described.
[0030]
First, an outline of the embodiment will be described.
[0031]
In the present embodiment, the injection mechanism portion is fixed and held in a form that does not require movement in consideration of heat insulation properties with respect to the mold clamping mechanism fixed side platen. At this time, a nozzle that touches the mold spool and pushes in the molten resin was attached to the tip of the injection cylinder, and the nozzle position accuracy was obtained by fitting the tip of the nozzle portion into a hole formed in the stationary platen. At the same time, the nozzle tip surface was flattened, and the amount of protrusion at the nozzle tip portion was strictly adjusted to touch the inlet portion of the spool portion provided in the mold in a flat shape. At this time, since the mold is pressed against the stationary platen by the clamping force, the resin does not leak during injection.
[0032]
The injection cylinder is attached to two blocks connected to the fixed platen and a jacket supported by the block with a heat insulating plate sandwiched between them, and the nozzle connected to the tip of the injection cylinder is also inserted into the hole of the fixed platen. By fitting with a minimum contact area and thereby mounting the injection cylinder so that it cannot move, heat transfer from the injection cylinder to the stationary platen is minimized.
[0033]
In addition, the mold structure is made a simple cassette mold by incorporating a mold mechanism on the mold clamping mechanism side. In addition, the fixed side platen can be eliminated by providing a mechanism for holding the fixed side template on the molding machine side. A spring or the like was provided between the plates to be held so that it was opened first when the mold was opened. In addition, a stop bolt for regulating the opening amount was incorporated. In addition, in order to support pinpoint gates, the runner lock take-out bar has a structure that has both functions of holding the runner and cutting the gate when the mold is opened, and has a structure that does not move with the injection pressure during injection. A pneumatic cylinder or the like is used for the lock extraction bar and the mold clamping mechanism so that the mold can be moved in and out. As a result, the stripper plate of the mold could be eliminated and the runner lock pin could be eliminated.
[0034]
The mold movable side is also provided with a shape that holds the mold movable side mold plate on the molder movable side platen, and a shape that receives the mold receiving plate part to apply a clamping force to the mold part. .
[0035]
The ejector that projects the molded product can be operated simultaneously with the mold opening.
[0036]
Hereinafter, embodiments of the present invention will be specifically described.
[0037]
(First embodiment)
FIG. 1 is a front view of a molding machine according to a first embodiment in which the present invention is applied to a plunger injection system of a vertical molding machine.
[0038]
FIG. 2 is a side view of FIG. FIG. 3 is a front view showing a state where the mold is opened.
[0039]
In FIG. 1, a hopper 1 stores a resin material and supplies the material to an injection cylinder 7 via a jacket 6. The injection cylinder 7 is fixed so as not to move by being attached to a jacket 6 supported by two blocks 10 connected to a stationary platen 12 with a heat insulating plate 11 interposed therebetween. A heater band 8 is wound around the injection cylinder 7 and controlled to a predetermined temperature according to the resin material to be used. The injection hydraulic cylinder 2 is fixed to a cylinder fixing plate 4 fixed by a block 10 erected from a stationary platen 12 and a pole 5 through a jacket 6. The injection plunger 3 is connected to the rod of the hydraulic cylinder 2 for injection.
[0040]
The mold clamping mechanism opens and closes the mold, the stationary platen 12, the stationary mold plate holder 13 that holds the fixed mold plate 19 of the cassette mold, the movable mold holder 14 that holds the movable side of the mold, and the mold. The mold clamping side hydraulic cylinder 17 for generating the mold clamping force, the mold clamping side cylinder connecting portion 16 for coupling the movable side holder 14 and the mold clamping cylinder 17, the fixed side mold plate holder 13, and the movable side holder 14. It comprises four tie bars 15 that guide the movement, and is fixed on an angle 18 that holds the whole.
[0041]
In FIG. 1, 20 is a cassette type movable side template, 21 is a cassette type receiving plate, 22 is a cassette type ejector pin, 23 is a cassette type return pin, and 24 is a cassette type ejector plate.
[0042]
In the side view of FIG. 2, a runner lock take-out bar 28, a runner separation plate 27, a runner lock take-out pneumatic cylinder 26, and a runner lock unit fixing plate 25 are shown. FIG. 3 shows the fixed side template holder 13, the tip spring 29, the fixed side template holder stopper bolt 30, and the molded product 31.
[0043]
FIG. 4 is an enlarged cross-sectional view of the side view shown in FIG. 2, showing an example of a pinpoint gate system.
[0044]
The resin material supplied into the injection cylinder 7 heated by the heater band 8 from the hopper 1 is melted at the portion of the toe beat 33 as the injection plunger 3 advances in the nozzle direction, and the mold contact of the stationary platen 12 is made. It is sent to the portion of the nozzle 35 fitted with a minimum contact area in the hole provided on the surface side, and injected into the runner portion 38 provided in the mold fixing side plate 19 with the nozzle needle valve 37 opened. Is done.
[0045]
Next, the resin passes through the runner portion 38, passes through the secondary spool 38a, passes through the gate portion, and forms the molded product 31. The runner portion 38 is composed of a runner shape provided on the mold fixing side mold plate 19 and a shape 38b provided on the runner lock take-out bar 28 shown in FIGS. 2, 4, 9, and 10. The tapered portion 38 a is formed on the runner lock take-out bar 28. Then, the gate is cut while holding the runner when the mold is opened as shown in FIG. The runner lock take-out bar 28 can be opened and closed without any problem by providing a shape for determining the position of the mold when the mold is clamped. At the same time, it is fixed with positioning pins or blocks so that the runner lock take-out bar 28 does not move due to the injection pressure.
[0046]
At the initial stage of mold opening, the fixed-side template holder 13 is opened before the parting surface on which the molded product 31 is located by the action of the fixed-side first opening spring 29. The opening amount is determined by the fixed side template holder stopper bolt 30. A partitioning lock mechanism may be provided on the fixed-side template holder 13 and the movable-side template holder 14 to replace the first opening spring 29.
[0047]
In the injection molding machine of the present embodiment, the nozzle 35 of the injection cylinder 7 is incorporated in the fixed side platen 12. The shape of the tip of the nozzle 35 is formed on a flat surface, and the protruding state of the fixed side platen 12 with respect to the surface in contact with the mold is in the range of approximately −0.3 mm to approximately 0.3 mm in a state where it can be molded. It is desirable to be.
[0048]
In FIG. 6, the runner lock take-out bar 28 is moved out of the mold by the operation of the runner lock take-out pneumatic cylinder 26, and at this time, the runner 38 is separated from the runner lock take-out bar 28 by the runner separation plate 27. After separation, the runner lock take-out bar 28 is returned to the mold.
[0049]
(Second Embodiment)
FIG. 7 is a diagram showing an embodiment when used in a direct gate of the two-plate system. In the present embodiment, the basic configuration and operation of the injection molding machine are substantially the same as those in the first embodiment.
[0050]
Also, the runner lock removal mechanism is not used for direct gates and side gates. Accordingly, the molten resin is injected directly from the nozzle 35 onto the spool 43 provided on the fixed-side template 19. The resin that has passed through the spool 43 forms a molded product 42. After the cooling is completed, the mold is opened, and the molded product 42 is removed by a take-out robot, manpower, or the like. When the mold is opened, the fixed-side template holder 13 is open in the same manner as the pinpoint gate in FIG. 8, but the fixed-side template holder 13 may be fixed so as not to open to the fixed-side platen 12.
[0051]
Further, in the present embodiment, the example of the vertical molding machine adopting the plunger injection method has been described, but the injection method may be an in-line screw method or a pre-plunger method. The molding machine body may be horizontal.
[0052]
As described above, the injection molding machine of the above-described embodiment is an injection molding machine having an injection mechanism part that melts and injects a resin and a mold clamping mechanism part to which a mold is attached. Since it is composed of a fixed-side platen, a fixed-side template holder for mounting a fixed-side mold plate of a mold, and a movable-side mold plate holder as a movable platen for mounting a movable-side mold plate of the mold, the injection mechanism section is A hole that is fixed to the stationary platen via a block, jacket, and heat insulating plate so that the injection cylinder cannot move, and the tip of the nozzle connected to the injection cylinder is drilled in the mold contact surface of the stationary platen With a minimum contact area and fixed in a precise position to minimize heat transfer to the stationary platen, and can be integrated with the stationary platen. Eliminates the need for the cylinder and the nozzle positioning mechanism, holes provided in the fixed side platen also can be minimized, it is possible to prevent a reduction in rigidity of the stationary platen, to allow for fabrication of compact mold structure.
[0053]
Further, the injection mechanism section has an injection cylinder, and the injection cylinder is attached to two blocks connected to the stationary platen and a jacket supported by the block with a heat insulating plate interposed therebetween. At this time, a nozzle for injecting the molten resin in contact with the mold spool is attached to the tip of the injection cylinder, and the tip of the nozzle is fitted with a hole provided in the fixed side platen with a minimum contact area, precisely The position is determined. As a result, the injection cylinder is mounted so that it cannot move, so that the contact area between the stationary platen and the nozzle portion can be minimized. As a result, heat transfer to the stationary platen can be minimized, integration with the stationary platen can be realized, the rigidity of the machine body can be improved, assembly is facilitated, and the injection mechanism can be moved. Cylinder and nozzle alignment are no longer necessary.
[0054]
Further, the mold attached to the mold clamping mechanism portion is composed of a fixed side mold and a movable side mold, the fixed side mold has a fixed side mold plate, and the movable side mold is , It has a movable side mold plate, a receiving plate, and an ejector member, and the movable side mold plate holder is connected to a hydraulic cylinder for clamping, and the mold is opened and closed, so that the mold structure is simplified and compact. And the setup time of the mold can be greatly shortened.
[0055]
Further, the nozzle of the injection cylinder is incorporated in the fixed side platen, and the bulge from the surface of the fixed side platen in contact with the mold with the shape of the tip of the nozzle as a flat surface is approximately −0.3 mm in the molded state. Because it can be adjusted within the range of ~ 0.3mm, the mold structure is simplified, it can be a cassette type with the same configuration and can accommodate a two-plate type gate, and the mold setup time is also It can be shortened.
[0056]
In addition, the runner lock take-out bar is provided with a structure that has both functions of holding the runner and cutting the gate when the mold is opened, so that it does not move with the injection pressure during injection and allows the mold to enter and exit. Is provided in the runner lock take-out bar and the mold clamping mechanism, so that the runner stripper plate and the runner lock pin used in the prior art can be deleted. As a result, the mold structure was simplified and the mold setup time could be greatly shortened.
[0057]
In addition, by providing the fixed side mold plate holder with a structure that enables holding of the above fixed side mold plate, it is possible to delete the fixed side mounting plate of the mold used in the prior art. . As a result, the mold structure is simplified, a cassette mold that can be used for the two-plate type gate system with the same configuration can be obtained, and the setup time of the mold can be greatly shortened.
[0058]
In addition, at the start of mold opening, there is a parting lock mechanism for the fixed-side mold plate holder and the working-side platen so that the pinpoint gate part is cut first so that the gap between the fixed-side mold plate holder and the fixed-side platen is opened first Therefore, the mold structure is simplified, the cassette structure can be made to be compatible with the two-plate type gate system with the same configuration, and the setup time of the mold can be greatly shortened.
[0059]
Also, at the start of mold opening, in order to cut the pinpoint gate part, a spring is incorporated between the fixed-side template holder and the working-side platen so that the fixed-side template holder and the fixed-side platen are opened first. Thus, since the restoring force of the spring is used, the mold structure is simplified and the setup time of the mold can be greatly shortened.
[0060]
In addition, the opening amount of the fixed-side template holder is adjusted by connecting the bolts raised from the movable platen to the fixed-side template holder, thus simplifying the mold and greatly reducing the setup time of the mold. be able to.
[0061]
In addition, since the ejector operation for ejecting the molded product is performed simultaneously with the mold opening, the mold structure is simplified and the setup time of the mold can be greatly shortened.
【The invention's effect】
As described above, according to the present invention, it is possible to provide an injection molding machine capable of reducing useless mechanisms and reducing the size and cost.
[Brief description of the drawings]
FIG. 1 is a front view of a molding machine according to a first embodiment in which the present invention is applied to a plunger injection system of a vertical molding machine.
FIG. 2 is a side view of FIG.
FIG. 3 is a view showing a state in which a mold is opened.
4 is an enlarged cross-sectional view centering on a mold part of FIG. 2;
5 is an enlarged cross-sectional view centering on the mold part of FIG. 2, and is a cross-sectional view showing a state where the mold is opened. FIG.
6 is a view showing a state in which the runner is discharged out of the mold in FIG. 5;
7 is an enlarged cross-sectional view of the center of a mold part in FIG. 2. FIG.
8 is a view showing a state in which a mold is opened in the cross-sectional view of FIG. 7;
FIG. 9 is an enlarged view of a side surface portion of the runner lock portion.
FIG. 10 is a view of a runner lock portion viewed from the front.
FIG. 11 is a view showing a conventional injection molding machine.
FIG. 12 is a diagram showing a cross section of a conventional three-plate mold.
13 is a view showing a state in which the three-plate mold shown in FIG. 12 is opened.
[Explanation of symbols]
1 Hopper 2 Injection Hydraulic Cylinder 3 Injection Plunger 4 Injection Hydraulic Cylinder Fixing Plate 5 Pole 6 Jacket 7 Injection Cylinder 8 Heating Band 9 Fixing Bolt 10 Block 11 Heat Insulating Plate 12 Fixed Side Platen 13 Fixed Side Template Holder 14 Movable Side Type Plate holder 15 Tie bar 16 Clamping side cylinder connecting part 17 Mold clamping side hydraulic cylinder 18 Angle 19 Cassette type fixed side mold plate 20 Cassette type movable side plate 21 Cassette type receiving plate 22 Cassette type ejector pin 23 Cassette type return pin 24 Cassette Die ejector plate 25 Runner lock take-out unit fixing plate 26 Pneumatic cylinder 27 for taking out runner lock Runner separation plate 28 Runner lock take-out bar 29 Fixed side die plate holder opening spring 30 Fixed side die plate Dah stopper bolt 31 moldings a
32 Extrusion Lot 33 Toe Beat 34 Nozzle Heater Band 35 Nozzle 36 Nozzle Spring 37 Needle Valve 38 Runner 38a Secondary Spool 38b Runner Taper 38c Nozzle Port 39 Ejector Plate Return Spring 40 Return Pin 41 Extrusion Lot Return Spring 42 Completed Product 43 Spool 44 Ejector connecting bar 45 Injection hydraulic cylinder 46 Injection unit moving cylinder 47 Injection unit moving guide rod 48 Injection plunger 49 Toe beat 50 Injection cylinder 51 Injection cylinder heater band 52 Nozzle 53 Nozzle heater 54 Fixed platen 55 Movable side platen 56 Mold clamping hydraulic cylinder 57 Tie bar 58 Fixed side mounting plate 59 Fixed side mold plate 60 Movable side template 61 Receiving plate 62 Movable side mounting plate 63 Pacer block 64 ejector plate 65 Eja compactors pin 66 cavity 67 spool runner 67a primary spool 67b runner 67c 2 primary spool 68 spool bush 69 locating ring 70 Runner lock pin 71 stripper plate 72 spring 73 Puller Bolts

Claims (3)

In an injection molding machine having an injection mechanism that melts and injects resin, and a mold clamping mechanism to which a mold is attached,
The mold clamping mechanism includes a fixed side platen, a fixed side mold plate holder for mounting a fixed side mold plate of the mold, and a movable side mold plate holder as a movable side platen for mounting a movable side mold plate of the mold. ,
The injection mechanism portion has an injection cylinder, and the injection cylinder is attached to a jacket supported by a block connected to the stationary platen. At the tip of the injection cylinder, molten resin is in contact with the spool portion of the mold. A nozzle for pouring is attached, the tip of the nozzle is fitted in a hole provided in the fixed platen, and the injection cylinder cannot move relative to the fixed platen in a state where the position is determined. An injection molding machine characterized by being attached . The injection molding machine according to claim 1, wherein the number of the blocks is two. The injection molding machine according to claim 1 or 2, wherein the heating cylinder is attached to the jacket with a heat insulating plate interposed therebetween.

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