JP4051216B2 - Mold for molding - Google Patents

Description

[0001]
[Industrial application fields]
This invention relates to a mold for molding for forming the shape of the I De plastic products using a combination of press-molding and injection molding.
[0002]
[Prior art]
As a method for molding a plastic product, an injection press molding method and an injection molding method are widely known.
[0003]
The injection press molding method is a method of injecting molten resin into the cavity with the mold slightly opened, pressing the molten resin by the pressing operation of the mold closing device, and cooling the molten resin to obtain a molded product It is. An injection press molding apparatus used in this method is configured to execute a press operation together with an injection operation, and an injection press molding die is generally composed of a male mold and a female mold.
[0004]
On the other hand, the injection molding method is a method in which a molten resin is injected into a cavity with a mold closed, and the molten resin is cooled to obtain a molded product. The injection molding apparatus used in this method is configured to execute an injection operation after a mold closing operation, and the injection mold is configured to define a cavity filled with a molten resin.
[0005]
Since both the injection press molding method and the injection molding method have a step of closing a mold and a step of injecting a molten resin, it is possible to use one apparatus for both methods by changing the control program. is there. However, there has been no idea of simultaneously performing injection press molding and injection molding using a single molding die, and simultaneously molding an injection press molded product and an injection molded product.
[0006]
[Problems to be solved by the invention]
Conventionally, there has been no idea of simultaneously molding an injection press-molded product and an injection-molded product. Therefore, in order to mold an injection press-molded product and an injection-molded product at the same time, a mold or There was a problem that a molding machine had to be prepared and the equipment cost was high.
[0007]
Another object of the present invention can reduce the equipment cost by simultaneously molding the injection molded article and injection press-molded article, it relates formed shape mold.
[0010]
[Means for Solving the Problems]
According to the first aspect of the present invention, a plurality of injection press cavities (55) ( (56a) (56b) ) and a plurality of injection cavities (57) ( by a fixed mold (10a) and a movable mold (10b)). (56c) (56d) ) , and holding the injection press pressure at the time of injection press molding and the injection pressure at the time of injection molding by one or a plurality of pressurizing means connected to the movable mold (10b) The mold (10) is a movable mold (10b ) in which the resultant force F1 of the press pressure P by the molten resin filled in the plurality of injection press cavities (55) ( (56a) (56b) ) at the time of injection press molding. ) And the point G0 at which the resultant force F0 of the pressurizing force by one pressurizing means or the pressurizing means by a plurality of pressurizing means is applied to the movable mold (10b) , and at the time of injection molding It acts on a plurality of injection cavities (57) ((56c) ( 56d)) resultant force F1 is movable die of the injection pressure P of the molten resin filled in (10b) A point that, as the resultant of one pressure applied by the pressing force F0 or more pressurizing means by pressurizing means F0 to match the G0 point which acts on the movable mold (10b), injection press cavity (55) And a molding die (10) "in which an injection cavity (57) is arranged.
[0011]
In the present invention, both the resultant pressure of the press pressure and the resultant force of the injection pressure acting on the movable mold (10b) are balanced in position with the pressure applied by the pressurizing means. That is, the resultant force of the pressure acting on the molding die (10) from the resin in the cavity at the time of injection press molding and injection molding, and the pressure acting on the molding die (10) from the pressing means Balance at one point.
[0012]
According to the second aspect of the present invention, “a single injection press cavity (55) (60a) and a plurality of injection cavities (57) ( (60b) (60c) by a fixed mold (10a) and a movable mold (10b)”. )) constitute, in the movable die (linked one or more mold to hold the injection press pressure and the injection pressure during injection molding of the injection press molding by pressurizing means 10b) (10) The point that the press pressure P by the molten resin filled in one injection press cavity (55) ((60a)) acts on the movable mold (10b) at the time of injection press molding and one pressurizing means The pressure F0 by the pressure or the resultant force F0 of the pressure applied by the plurality of pressurizing means coincides with the point G0 acting on the movable mold (10b) , and a plurality of injection cavities (57) ( (60b) (60c) In the point that the resultant force F1 of the injection pressure P of the molten resin filled in is applied to the movable mold (10b) , The injection press cavity (55) and the injection cavity (57) are arranged so that the applied pressure F0 or the resultant force F0 of the pressure applied by the plurality of pressurizing means coincides with the point G0 acting on the movable mold (10b) . Molding die (10) ”.
According to the third aspect of the present invention, “a plurality of injection press cavities (55) ( (62a) (62b) ) and one injection cavity (57) ( by a fixed mold (10a) and a movable mold (10b)” ). (62c) ), and a molding die (10) which holds the injection press pressure at the time of injection press molding and the injection pressure at the time of injection molding by one or a plurality of pressurizing means connected to the movable die (10b). ) And the resultant force F1 of the press pressure P by the molten resin filled in the plurality of injection press cavities (55) ( (62a) (62b) ) acts on the movable mold (10b) at the time of injection press molding. The point G0 coincides with the point G0 at which the applied force F0 by one pressurizing means or the resultant force F0 of the pressurizing means by a plurality of pressurizing means acts on the movable mold (10b) , and one injection at the time of injection molding and that the injection pressure P of the molten resin filled in the cavity (57) ((62c)) is applied to the movable mold (10b), one Pressurizing means by pressure F0 or more of the resultant force of pressure applied by the pressurizing means F0 is movable mold so that the G0 that acts to match the (10b), injection press cavity (55) and injection cavity (57) Is a molding die (10) ".
[0013]
As in these inventions, there may be one injection press cavity (55) and a plurality of injection cavities (57), a plurality of injection press cavities (55), and a single injection cavity (57). There may be.
[0014]
According to a fourth aspect of the present invention, there is provided a molding die (10) according to any one of the first to third aspects, wherein "a common cavity in which an injection press cavity (55) and an injection cavity (57) are integrated. (58) ”.
[0015]
In this invention, since the injection press cavities (55) (56a) and the injection cavities (57) (56c) constituting the common cavity (58) are functionally independent, other physically independent injection presses There is no substantial difference between the cavity (55) (56b) and the injection cavity (57) (56c).
[0017]
【The invention's effect】
According to the first to fourth aspects of the present invention, in each of the injection press molding and the injection molding, the resultant force of the pressure acting on the movable mold constituting the molding mold from the resin in the cavity (injection press cavity) Alternatively, the pressure acting on the movable mold when one of the injection cavities is one) and the pressure acting on the movable mold from the pressurizing means (such as a hydraulic cylinder) (the resultant force when there are a plurality of pressures) And balance in position. Therefore, in both the injection press cavity and the injection cavity, the press pressure and the injection pressure can be maintained uniformly, and the occurrence of molding defects such as burrs can be prevented.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
A molding die (10) according to an embodiment of the present invention shown in FIGS. 1 and 2 is an injection molding machine (12) as shown in FIG. 3 for simultaneously molding an injection press molded product and an injection molded product. ) And used. Here, the “injection press-molded product” refers to a molded product that is injection-press molded in the injection press cavity (55), and the “injection molded product” refers to a molding that is injection-molded in the injection cavity (57). "Shared molded product" means common molding (in the shared cavity) (in which the injection press cavity (55) and injection cavity (57) are integrally formed). This means a molded product which is a molding method in which a resin is injected and filled after injection pressing.
[0019]
The molding die (10) has a fixed die (10a) and a movable die (10b) that form a plurality of cavities (56a) to (56d) in cooperation with each other, and each of the cavities (56a) to (56a) The arrangement of (56d) has the feature of this embodiment.
[0020]
The arrangement of the cavities (56a) to (56d) is determined in relation to the pressure F0 received by the movable mold (10b) from the injection molding machine (12). The outline of 12) will be described, and then the molding die (10) will be described in detail.
[0021]
As shown in FIG. 3, the injection molding machine (12) has a fixed platen (14) and a base (16), and a plurality of (four in this embodiment) are provided on the fixed platen (14). The mold clamping device (20) is connected via the tie bar (18). In addition, a fixed mold (10a) of a molding die (10) is attached to the upper part of the fixed plate (14), and a movable die plate (24) is slidably attached to the tie bar (18). A hydraulic cylinder (22) as a pressurizing means is attached to the fastening device (20). Then, on the surface of the movable die plate (24) facing the fixed mold (10a), the movable mold (10b) of the molding die (10) is attached, and the surface facing the mold clamping device (20) The piston (26) which comprises a hydraulic cylinder (22) is connected to.
[0022]
The injection machine (28) is placed on the base (16). The injection machine (28) includes a heating cylinder (30), a screw (32) is accommodated in the heating cylinder (30), and a hopper (34) is attached to an upper portion of the heating cylinder (30). . A nozzle (36) formed at the tip of the heating cylinder (30) is connected to a sprue bush (38) formed in a side portion of the fixed mold (10a).
[0023]
The form of the injection molding machine is not limited to this embodiment, and for example, an injection molding machine in which the movable mold moves in the lateral direction may be used.
[0024]
As described above, the molding die (10) includes the fixed die (10a) attached to the fixed platen (14) and the movable die (10b) attached to the movable die plate (24).
[0025]
As shown in FIGS. 1 and 2, the fixed mold (10a) includes a plate-shaped mold body (40), and the surface of the mold body (40) facing the movable mold (10b) A plurality of molds (female molds in this embodiment) (46) that form cavities (56a) to (56d) in cooperation with a mold (44) (see FIG. 2) formed on the movable mold (10b); A guide pin hole (42) (see FIG. 1) to be engaged with the guide pin (54) formed in the movable mold (10b) is formed. A sprue bush (38) (see FIG. 3) is formed on the side surface (the surface facing the injection machine (28)) of the mold body (40), and the sprue bush (38) is formed inside the mold body (40). A plurality of runners (48) communicating the bush (38) and the respective molds (46) are formed. Furthermore, each runner (48) is provided with a valve gate (50) for adjusting the injection start timing and the injection amount of the molten resin.
[0026]
As shown in FIGS. 1 and 2, the movable mold (10b) includes a plate-shaped mold body (52), and the surface of the mold body (52) facing the fixed mold (10a) A plurality of molds (male molds in this embodiment) (44) (see FIG. 2) constituting cavities (56a) to (56d) in cooperation with a mold (46) formed in the fixed mold (10a); A guide pin (54) engaged with a guide pin hole (42) formed in the fixed mold (10a) is formed.
[0027]
In the molding die (10), as described above, the cavities (56a) to (56d) are configured by the die (46) of the fixed die (10a) and the die (44) of the movable die (10b). However, in the molding die (10) of this example, the cavities (56a) and (56b) are the injection press cavities (55), and the cavities (56c) and (56d) are the injection cavities (57). Is done.
[0028]
In these cavities (56a) to (56d), as shown in FIG. 2, the pressure P (injection pressure or press pressure) of the molten resin acts on the inner surface of the mold (44) in the movable mold (10b). Therefore, if the resultant force F1 of the pressure P acting on the entire movable mold (10b) is not positionally balanced with the pressure F0 applied by the piston (26) of the hydraulic cylinder (22), the movable mold (10b) A shearing force is applied to the movable mold (10b) by the applied force F0 for closing and the resultant force F1 for opening, so that the pressure of the molten resin is uniformly maintained in each of the cavities (56a) to (56d). Can not.
[0029]
Therefore, in this embodiment, the injection press cavity (55) ((56a) and (56b)) and the injection cavity (57) ((56c) and (56d)) are connected to each other, and the movable mold (10b) is connected to the piston (26 ), The following arrangement is made.
[0030]
That is, as shown in FIG. 4, an xy coordinate system is assumed with the point where the movable mold (10b) receives the applied pressure F0 from the piston (26) as G0 and the point G0 as the origin. In this coordinate system, the injection press cavities (55) ((56a) and (56b)) are arranged according to the equation (1), and the injection cavities (57) ((56c) and (56d)) are expressed by the equation (2). Arrange according to the formula.
[0031]
However, “the resultant action point” in the equations 1 and 2 refers to the point at which the resultant force f (pressure P × area S: the same applies hereinafter) acts in each of the cavities (56a) to (56d). Then, it coincides with the center of gravity of a figure (hereinafter referred to as “orthographic projection figure”) obtained by orthographic projection of each of the cavities (56a) to (56d) onto the coordinate system.
[0032]
[Equation 1]
Xa * P * Sa = Xb * P * Sb
Ya × P × Sa = Yb × P × Sb
Xa: x-axis direction distance from origin G0 to resultant force acting point Ga of cavity (56a) Xb: x-axis direction distance from origin G0 to resultant force acting point Gb of cavity (56b) Ya: origin G0 to cavity (56a) Y-axis direction distance Yb to resultant force action point Ga: Y-axis direction distance Sa from origin G0 to resultant force action point Gb of cavity (56b) Sa: Area of orthographic figure corresponding to cavity (56a) Sb: Cavity (56b) The area P of the orthographic figure corresponding to: pressure acting on the inner surface of the mold (46) (pressing pressure)
[Equation 2]
Xc * P * Sc = Xd * P * Sd
Yc * P * Sc = Yd * P * Sd
Xc: x-axis direction distance from origin G0 to resultant force action point Gc of cavity (56c) Xd: x-axis direction distance from origin G0 to resultant force action point Gd of cavity (56d) Yc: origin G0 to cavity (56c) Y-axis direction distance Yd to resultant force action point Gc: Y-axis direction distance Sc from origin G0 to resultant force action point Gd of cavity (56d) Sc: Area of orthographic figure corresponding to cavity (56c) Sd: Cavity (56d) The area P of the orthographic figure corresponding to: pressure acting on the inner surface of the mold (46) (injection pressure)
When the respective cavities (56a) to (56d) are arranged according to the equations (1) and (2), the resultant force F1 of the pressure P acting on the entire movable mold (10b) is generated by the hydraulic cylinder (22) (piston (28)). Positionally balanced with the applied pressure F0. That is, the moment (centered around the origin G0) that is conceived by the resultant force f is balanced in each of the cavities (56a) to (56d), and the action line of the applied force F0 and the action line of the resultant force F1 coincide.
[0033]
Therefore, the movable die (10b) is not subjected to a force for rotating the origin G0 around the origin G0, and the injection pressure and the press pressure can be uniformly maintained in the cavities (56a) to (56d).
[0034]
In this embodiment, since the surface on which the pressure P for opening the movable mold (10b) acts (hereinafter referred to as “pressure surface”) is orthogonal to the mold opening direction, each cavity (56a ) To (56d), the center of gravity of the orthographic figure coincides with the resultant action point. However, when the pressing surface is inclined with respect to the mold opening direction, the center of gravity of the orthographic figure and the resultant action point may not coincide with each other, and therefore, the determination of the resultant action point requires caution.
[0035]
Hereinafter, a method of simultaneously molding a plurality of injection press-molded products and a plurality of injection-molded products using the molding die (10) will be described according to the timing chart of FIG.
[0036]
When the molding die (10) is mounted on the injection molding machine (12) and the drive switch of the injection molding machine (12) is turned on, first, the mold closing operation of the molding die (10) is started, and the movable mold The mold (10b) is displaced in the closing direction. The injection press molding process is started at a predetermined timing before the molding die (10) is completely closed. That is, a required amount of molten resin is injected into the injection press cavity (55) ((56a) and (56b)), the movable mold (10b) is further displaced in the closing direction, and the molten resin is pressed. In the injection press molding process, the injection of molten resin into the injection cavity (57) ((56c) and (56d)) is prohibited by operating the valve gate (50), and the injection press cavity (55) ((56a ) And (56b)) is set to a low injection pressure.
[0037]
When the molding die (10) is completely closed, the next injection molding process is started. That is, by operating the valve gate (50), the injection of molten resin into the injection press cavity (55) ((56a) and (56b)) is prohibited, and the injection cavity (57) ((56c) and (56d) )) Molten resin is injected into the inside. In this process, the injection pressure of the molten resin is set higher than in the injection press molding process. After the molten resin is filled into the injection cavity (57) ((56c) and (56d)), the injection is continued for a predetermined time for holding pressure.
[0038]
In the next cooling step, the molten resin is cooled and cured while the molding die (10) is closed. When the molten resin is completely cured, the mold opening operation of the molding die (10) is started, and the movable die (10b) is displaced in the opening direction. Then, the molded product is released from the mold.
[0039]
According to this embodiment, since one press mold (10) can be used to continuously perform injection press molding and injection molding, in order to mold an injection press molded product and an injection molded product, There is no need to prepare a plurality of molding dies. Therefore, the equipment cost can be greatly reduced.
[0040]
Further, in each of the injection press molding and the injection molding, the resultant force F1 of the pressure P acting on the entire movable mold (10b) from the molten resin in the cavities (56a) to (56d) and the pressurizing means Since the applied pressure F0 acting on the movable mold (10b) from the piston (28) can be balanced in position, the press pressure and the injection pressure can be set in any of the cavities (56a) to (56d). Can be held uniformly. Therefore, occurrence of molding defects such as burrs can be prevented.
[0041]
In the injection press molding process, the molten resin is pressurized with a predetermined pressure by the piston (28), and in the injection molding process, the injection pressure of the molten resin is held with a predetermined holding force by the piston (28). Since the molded product is obtained in stages, the capacity of the piston (28) can be effectively utilized in two processes that are temporally mixed. Therefore, compared with the case where only one of injection press molding or injection molding is performed using the hydraulic cylinder (22) (piston (28)) of the same capacity, the total projected area of the molded product that can be molded in one process is reduced. It can be greatly increased.
[0042]
In the above-described embodiment, the resultant action points Ga to Gd of the cavities (56a) to (56d) are shifted from each other in both the x-axis direction and the y-axis direction. For example, as shown in FIG. In addition, the resultant force action points Ga to Gd may be arranged on the x axis (or on the y axis).
[0043]
In the above-described embodiment, the pressing force F0 is applied to the center of the movable mold (10b) by one hydraulic cylinder (22). For example, the movable mold is formed by a plurality of hydraulic cylinders (22). A pressing force may be applied to the peripheral edge of (10b). In this case, the point where the resultant force F0 of the applied pressure by each hydraulic cylinder (22) (piston (26)) acts is G0.
[0044]
Further, the pressurizing means may be a toggle mechanism driven by a motor, an air cylinder or the like instead of the hydraulic cylinder (22).
[0045]
For example, as shown in FIG. 6, the injection press cavities (55) and (56a) and the injection cavities (57) and (56c) may be integrally formed as a common cavity (58). Also in this shared cavity (58), the injection press cavities (55) and (56a) and the injection cavities (57) and (56c) are functionally independent. It can be applied as it is.
[0046]
In each of the above-described embodiments, the case where there are a plurality of injection press cavities (55) and injection cavities (57) (including those constituting the common cavity (58)) is shown. ) Or injection cavity (57) may be one. For example, as shown in FIG. 7, there may be one injection press cavity (55) (60a) and two injection cavities (57) ((60b) (60c)), as shown in FIG. As described above, there may be two injection press cavities (55) ((62a) (62b)) and one injection cavity (57) (62c).
[0047]
Further, for example, in the embodiment of FIG. 7, one of the injection press cavity (55) (60a) and the two injection cavities (57) ((60b) (60c)) is integrated as a common cavity (not shown). In the embodiment of FIG. 8, either one of the two injection press cavities 55 ((62a) (62b)) may be integrally formed as a common cavity (not shown). Good.
[0048]
In this way, it goes without saying that the above formulas 1 and 2 can be applied as they are even when one of the injection press cavity (55) and the injection cavity (57) is one.
[0049]
Further, in the injection press molding step, instead of the method of pressing while injecting the molten resin into the injection press cavity (55), a method of pressing after the injection of the molten resin may be adopted.
[0050]
In addition, the kind of resin used in this invention is not specifically limited.
[Practicality verification by prototype]
The inventors made a prototype of the molding die (10) of the embodiment of FIG. 6 according to the following conditions (a) to (d), and confirmed that a molded product having a target shape could be obtained.
[0051]
(A) Injection press cavity (55) (56b):
Area of orthographic figure Sb = 4100 cm ²
Resulting point Gb (x, y) = (− 61, 0)
(B) Injection cavity (57) (56d):
Area of orthographic figure Sd = 1100 cm ²
Resultant force point Gd (x, y) = (− 843,0)
(C) Injection press cavity (56a) included in the common cavity (58):
Area of orthographic figure Sa = 1300 cm ²
Resultant force point Ga (x, y) = (193,0)
(D) Injection cavity (56c) included in common cavity (58):
Area of orthographic figure Sc = 1100 cm ²
Resultant force acting point Gc (x, y) = (843,0)
(E) Injection molding machine:
Clamping force 670ton
(F) Material:
MI (melt flow index) = 20 g / 10 min
[Brief description of the drawings]
FIG. 1 is a perspective view showing a molding die according to an embodiment of the present invention.
FIG. 2 is a partial cross-sectional view showing a molding die of FIG. 1 embodiment.
3 is a view showing an injection molding machine to which the molding die of FIG. 1 embodiment is applied.
FIG. 4 is a diagram showing an arrangement state of each cavity in the embodiment of FIG. 1;
FIG. 5 is a timing chart showing a molding method according to an embodiment of the present invention.
FIG. 6 is a view showing another arrangement state of each cavity.
FIG. 7 is a view showing still another arrangement state of each cavity.
FIG. 8 is a diagram showing still another arrangement state of each cavity.
[Explanation of symbols]
(10) ... Molding die (10a) ... Fixed die (10b) ... Moveable die
(12)… Injection molding machine
(14)… Fixed platen
(16)… Base
(18) ... Tie bar
(20)… Clamping device
(22)… Hydraulic cylinder
(24)… Moveable die plate
(26) ... Piston
(28)… Injector
(38)… Sprue bush
(48)… Runner
(50)… Valve gate
(44), (46) ... Type
(56a), (56b) ... Injection press cavity
(56c), (56d) ... Injection cavity

Claims (4)

A fixed mold and a movable mold constitute a plurality of injection press cavities and a plurality of injection cavities, and one or a plurality of pressurizing means connected to the movable molds at the time of press pressure and injection molding at the time of injection press molding. A mold for holding the injection pressure of
At the time of injection press molding, the combined force of the press pressure by the molten resin filled in the plurality of injection press cavities acts on the movable mold, and the pressing force by the one pressing means or the plurality of pressing means The resultant force of the pressing force is applied to the movable die, and the resultant force of the injection pressure of the molten resin filled in the plurality of injection cavities during the injection molding acts on the movable die. The injection press cavity and the injection cavity are arranged so that the point coincides with the point at which the applied pressure by the one pressing means or the resultant force of the plurality of pressing means acts on the movable mold. Mold for molding. A fixed mold and a movable mold constitute one injection press cavity and a plurality of injection cavities, and one or a plurality of pressurizing means connected to the movable mold is used for press pressure and injection molding at the time of injection press molding. A mold for holding the injection pressure of
At the time of injection press molding, the pressing pressure by the molten resin filled in the one injection press cavity acts on the movable mold, and the pressing force by the one pressing means or the pressing force by the plurality of pressing means. A point where the resultant force of the pressure is applied to the movable mold and the resultant force of the injection pressure of the molten resin filled in the plurality of injection cavities during the injection molding is applied to the movable mold; The molding in which the injection press cavity and the injection cavity are arranged so that the pressure applied by the one pressurizing unit or the resultant force of the pressurizing units by the plurality of pressurizing units coincides with the point acting on the movable mold. Mold. A fixed mold and a movable mold constitute a plurality of injection press cavities and a single injection cavity, and one or a plurality of pressurizing means connected to the movable molds at the time of press pressure and injection molding at the time of injection press molding. A mold for holding the injection pressure of
At the time of injection press molding, the combined force of the press pressure by the molten resin filled in the plurality of injection press cavities acts on the movable mold, and the pressing force by the one pressing means or the plurality of pressing means And the point where the resultant force of the applied pressure acts on the movable mold, and the injection pressure of the molten resin filled in the one injection cavity acts on the movable mold at the time of injection molding The molding in which the injection press cavity and the injection cavity are arranged so that the pressure applied by the one pressurizing unit or the resultant force of the pressurizing units by the plurality of pressurizing units coincides with the point acting on the movable mold. Mold. The molding die according to any one of claims 1 to 3 , comprising a common cavity in which the injection press cavity and the injection cavity are integrated.

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