JP6100726B2 - Injection mold - Google Patents

Description

  The present invention relates to a technical field of an injection mold having a fixed mold and a movable mold that form a cavity filled with molten resin by being abutted, and that opens and closes the gate of each nozzle by a plurality of gate opening and closing pins. .

JP 2010-234541 A JP 2002-96359 A

  There is a mold for injection molding which has a fixed mold and a movable mold and molds a molded product by filling a cavity which is a space formed by a combination of a concave mold (concave part) and a convex mold (convex part). . Such an injection mold is assembled in an injection molding machine as a part of its structure.

  Such injection molds include a structure called a hot runner system in which molten resin is heated toward a cavity while being heated by a heater (for example, Patent Document 1 and Patent Document 1). Patent Document 2). The hot runner system includes a sprue to which a molten resin is supplied from a resin supply unit of an injection molding machine, a manifold into which the molten resin flows from the sprue, and a plurality of nozzles to which the molten resin is supplied from the manifold. Are formed as gates, and molten resin is discharged from each gate into the cavities and filled.

  In the injection mold, a plurality of gate opening / closing pins that open and close the gates of the respective nozzles are arranged so as to be movable in the axial direction, and when the gate opening / closing pins are moved to one side, the gate is closed and the molten resin When the gate opening / closing pin is moved to the other side, the gate is opened and the molten resin is discharged into the cavity.

  In the injection mold described in Patent Document 1, a hot runner system having a sprue, a manifold, and a plurality of nozzles is disposed inside a movable mold. Each movable opening / closing pin and a plate (extrusion plate) for moving the gate opening / closing pin are also arranged inside the movable mold. Each gate opening / closing pin is inserted into each nozzle in a state where it can move in the axial direction. One end of the pin is coupled to the plate. When the plate is moved in the axial direction of the gate opening / closing pin by an ejector rod provided as a drive unit, each gate opening / closing pin is moved in the axial direction together with the plate.

  In the injection mold described in Patent Document 2, a hot runner system having a sprue, a manifold, and a plurality of nozzles is arranged inside a fixed mold. Inside the fixed mold, each gate open / close pin and a plate (pin plate) for moving the gate open / close pin are also arranged, and the gate open / close pin is inserted into each nozzle so as to be movable in the axial direction. One end of the pin is coupled to the plate. A driving part for moving the gate opening / closing pin is also disposed inside the fixed mold together with the hot runner system, and a piston and a cylinder for supporting the piston are provided as the driving part. The piston and the cylinder are arranged outside the plurality of gate opening / closing pins in a direction orthogonal to the axial direction of the gate opening / closing pins. The plurality of gate opening / closing pins are moved in the axial direction integrally with the plate by moving the plate in the axial direction of the gate opening / closing pins by the piston.

  However, in the injection mold described in Patent Document 1, a plate and a gate opening / closing pin are arranged together with a hot runner system inside a movable mold that is moved with respect to a fixed mold. These hot runner systems, plates, and gate opening / closing pins are moved along with the movement of the movable mold during the movement of the mold, which hinders the simplification of the overall structure of the injection mold. . In addition, since the hot runner system, the plate, and the like are moved together with the movable type, the weight of the movable type structure is increased correspondingly, and a large driving force is required for the movement.

  On the other hand, in the injection mold described in Patent Document 2, since the hot runner system, the plate and the like are arranged inside the fixed mold, the overall structure of the injection mold can be simplified. As shown in the figure, a drive unit having a piston and a cylinder is disposed inside the fixed mold. Therefore, since the drive unit is arranged inside the fixed mold, the injection mold becomes large, which hinders downsizing of the injection mold.

  In addition, an injection mold having a piston and a cylinder as a drive unit is not provided with a plate, the piston and the cylinder are arranged in the axial direction of each gate opening / closing pin, and each piston is opened and closed by a gate. There is a configuration in which the gate opening / closing pin is moved to one side by pressing the pin from the axial direction, and the gate opening / closing pin is moved to the other side by releasing the pressing of each piston to the gate opening / closing pin.

  However, in such an injection mold in which the piston and the cylinder are arranged in the axial direction of each gate opening / closing pin, one gate opening / closing pin is located inside the outer diameter of each cylinder. Because of the configuration, the distance (pitch) between multiple gate opening / closing pins depends on the cylinder outer diameter, which increases the pitch between the gate opening / closing pins and hinders the miniaturization of injection molds. There is a fear.

  In addition, in the injection mold in which the drive unit is arranged inside the fixed mold together with the hot runner system, the heat generated in the hot runner system is affected to the drive unit, so the operation of the drive unit There is a possibility that a failure may occur, or it may be necessary to provide a heat blocking mechanism or a cooling mechanism for the drive unit.

  Therefore, an object of the injection molding die of the present invention is to overcome the above-described problems, simplify the structure and reduce the size, and improve the reliability of the operation in the drive unit.

First, an injection mold according to the present invention is an injection mold having a fixed mold and a movable mold that form a cavity filled with molten resin by being abutted against each other, from a resin supply unit. The sprue to which the molten resin is supplied, the flow path through which the molten resin flows from the sprue and the molten resin flows, the manifold disposed inside the stationary mold, and the flow path in which the molten resin flows A plurality of nozzles each having a gate for discharging the molten resin toward the cavity, a plurality of gate opening / closing pins that are moved in the axial direction to open and close the gate, and the gate opening / closing pin is moved in the axial direction to be fixed. and a drive portion supported on the outer end of the mold, said the fixed guide shaft for guiding is provided the gating pin in the axial direction, said Ma Sort hold and the drive unit are spaced apart in the moving direction of the gate opening and closing pin, the guide shaft and the manifold arrangement spaced apart in a direction perpendicular to the arrangement direction of the driving part and the manifold, wherein the drive unit is the Driven by a drive source disposed outside the outer surface of the fixed mold, the driving force of the drive unit is transmitted to the plurality of gate opening / closing pins, and the plurality of gate opening / closing pins are moved in the axial direction.

  As a result, the driving force of the drive unit driven by the drive source arranged outside the outer surface of the fixed mold is transmitted to the plurality of gate opening / closing pins, and the plurality of gate opening / closing pins are respectively moved in the axial direction. The gate is opened and closed by a gate opening / closing pin.

  Second, in the above-described injection mold according to the present invention, an ejector pin that protrudes a molded product molded in the cavity and takes out the molded product from the cavity to the movable mold is movable in the axial direction. It is desirable to be supported by.

  As a result, the ejector pin and the gate opening / closing pin are positioned separately in the movable type and the fixed type, respectively.

  Third, in the above-described injection mold according to the present invention, a valve drive plate that is movable in the axial direction of the gate opening / closing pin according to the operation of the drive unit is disposed inside the fixed mold, The gate opening / closing pin is preferably provided with one end portion in the axial direction as a gate opening / closing portion for opening and closing the gate, and the other end portion in the axial direction as a coupling portion coupled to the valve drive plate.

  Thereby, the plurality of gate opening / closing pins are simultaneously moved by the valve driving plate.

Fourthly, in the above-described injection mold according to the present invention, a plurality of the guide shafts are provided, and the valve drive plates are supported by the plurality of guide shafts so as to be movable in the axial direction. It is desirable that the shaft is disposed outside the manifold in a direction perpendicular to the moving direction of the valve drive plate.

  Thereby, the distance of a guide shaft is enlarged and the inclination of a valve drive plate is suppressed.

  Fifth, in the injection mold according to the present invention described above, a plurality of the drive parts are provided, and the plurality of drive parts pass through the central part of the valve drive plate in the moving direction of the valve drive plate. It is desirable that they are positioned at equal intervals in the circumferential direction around the extending axis.

  As a result, an equal driving force is easily transmitted from the driving unit to the valve driving plate with reference to the central portion, and the gate opening / closing pin is moved in the axial direction while the inclination of the valve driving plate is suppressed.

  Sixth, in the injection mold according to the present invention described above, a plurality of the drive parts are provided, and the plurality of drive parts pass through the central part of the valve drive plate in the moving direction of the valve drive plate. It is desirable that they are positioned at equal intervals in the radial direction with respect to the extending axis.

  As a result, an equal driving force is easily transmitted from the driving unit to the valve driving plate with reference to the central portion, and the gate opening / closing pin is moved in the axial direction while the inclination of the valve driving plate is suppressed.

  Seventhly, in the above-described injection mold according to the present invention, the driving force of the driving unit is transmitted between the driving unit and the valve driving plate in the same direction as the valve driving plate. A rotating body that is rotatable about a fulcrum shaft perpendicular to the axial direction of the gate opening / closing pin is supported on the valve drive plate, the working plate is in contact with the outer peripheral surface of the rotating body, It is preferable that the driving force of the driving unit is transmitted from the working plate to the valve driving plate via the rotating body.

  As a result, the gate opening / closing pin is moved in the axial direction while the inclination of the valve drive plate is suppressed.

  Eighth, in the injection molding die according to the present invention described above, the drive force of the drive unit is transmitted between the drive unit and the valve drive plate in the same direction as the valve drive plate. A transmission protrusion having a curved surface portion in contact with the valve drive plate or the action plate is provided on one of the action plate or the valve drive plate, and the driving force of the drive part is transmitted to the transmission protrusion. It is desirable to transmit from the working plate to the valve drive plate via

  As a result, the gate opening / closing pin is moved in the axial direction while the inclination of the valve drive plate is suppressed.

  According to the present invention, the driving force of the driving unit driven by the driving source disposed outside the outer surface of the fixed mold is transmitted to the plurality of gate opening / closing pins disposed inside the fixed mold, thereby the plurality of gate opening / closing pins. Are moved in the axial direction, and the gates of the nozzles are opened and closed by the gate opening / closing pins, so that the structure can be simplified and miniaturized, and the reliability of the operation in the drive unit can be improved.

FIG. 2 to FIG. 11 show an embodiment of the present invention, which is a cross-sectional view of an injection mold shown in a state where a fixed mold and a movable mold are separated from each other. 3 and 4 show the operation of the injection mold, and this figure is a cross-sectional view showing a state in which the fixed mold is moved and butted against the movable mold. FIG. 3 is a cross-sectional view illustrating a state in which the cavity is filled with a molten resin following FIG. 2. FIG. 4 is a cross-sectional view illustrating a state where the gate is closed by a gate opening / closing pin, following FIG. 3. FIG. 6 to FIG. 11 show a modification example, and this figure is a cross-sectional view showing a first modification example. It is an expanded sectional view showing the state where the action plate inclined in the 1st modification. It is an expanded sectional view showing the 2nd modification. It is an expanded sectional view which shows virtually the state where the action plate inclined in the 2nd modification. It is an expanded sectional view showing the example in which the concave surface was formed in the valve drive plate in the 2nd modification. It is an expanded sectional view which shows the example in which the transmission protrusion was provided in the valve drive plate in the 2nd modification. It is an expanded sectional view showing the example in which the transmission projection was provided in the valve drive plate in the 2nd modification, and the concave surface was formed in the action plate.

  EMBODIMENT OF THE INVENTION Below, the form for implementing the injection mold of this invention is demonstrated with reference to an accompanying drawing.

  In the following description, the up / down / front / rear / right / left directions are shown with the direction in which the fixed mold and the movable mold of the injection mold are separated from each other as the vertical direction. In addition, the up-down, front-back, left-right directions shown below are shown for convenience of explanation, and the present invention is not limited to these directions. Further, the quantity, shape, arrangement, and the like of each part are not limited to the contents shown in the scope without departing from the intention of the present invention.

<Injection mold structure>
First, the structure of the injection mold 1 will be described (see FIG. 1).

  The injection mold 1 is assembled to an injection molding machine as a part of its structure, and has a movable mold 2 and a fixed mold 3 that are separated from each other in the vertical direction. An inner space is formed in the fixed mold 3, and this inner space is an arrangement space 4. On the lower end portion of the fixed mold 3, recessed portions 3a, 3a,... Opened downward are formed. The recesses 3a, 3a,... Are spaced apart in the horizontal direction.

  The movable mold 2 is moved up and down with respect to the fixed mold 3 so as to be separated. The movable mold 2 is formed in a substantially flat plate shape whose thickness direction is set in the vertical direction, and is combined with the recesses 3a, 3a,... Formed in the fixed mold 3 when it is abutted with the fixed mold 3 on the upper surface side. Have a plurality of convex portions 2a, 2a,... Formed as cavities 5, 5,. The convex portions 2a, 2a,... Are spaced apart in the horizontal direction.

  The movable mold 2 is formed with insertion holes 2b, 2b,... Communicating with the convex portions 2a, 2a,. The insertion hole 2b extends in the vertical direction, and an ejector pin 6 is supported in the insertion hole 2b so as to be movable in the vertical direction. In a state before the molten resin described later is filled in the cavities 5, 5,..., The upper surface of the ejector pin 6 coincides with the upper surface of the convex portion 2a.

  The fixed die 3 is a flat plate-shaped mounting plate 7 facing in the vertical direction, a cavity plate 8 positioned below the mounting plate 7, and a connecting plate that connects the outer peripheral portion of the mounting plate 7 and the outer peripheral portion of the cavity plate 8. 9. An arrangement space 4 is formed inside the fixed mold 3 by the mounting plate 7, the connecting plate 9, and the cavity plate 8.

  A nozzle insertion hole 7 a penetrating vertically is formed in the central portion of the mounting plate 7. In the mounting plate 7, for example, two support holes 7b and 7b penetrating vertically outside the nozzle insertion hole 7a are formed so as to be separated from each other in the left-right direction. In the mounting plate 7, for example, two guide mounting holes 7c and 7c opened downward to the outside of the support holes 7b and 7b are formed apart from each other in the left and right directions.

  An annular locating ring 10 is attached to the upper surface of the mounting plate 7, and the center hole 10a of the locating ring 10 is aligned with the nozzle insertion hole 7a. The locating ring 10 has a function of positioning with respect to the injection molding machine when assembled to the injection molding machine.

  A supply nozzle 100 that functions as a resin supply unit that supplies molten resin is inserted into the nozzle insertion hole 7 a of the mounting plate 7. Drive rods 11 and 11 that function as drive units are supported in support holes 7b and 7b of the mounting plate 7 so as to be movable in the vertical direction. Since the mounting plate 7 is positioned at the outer end portion of the fixed mold 3, the drive rods 11, 11 that function as the drive section are also positioned at the outer end portion of the fixed mold 3.

  The drive rods 11 and 11 are respectively driven by drive sources 200 and 200 arranged above the fixed mold 3, that is, outside the outer surface of the fixed mold 3, and are moved in the vertical direction with respect to the mounting plate 7.

  As the drive source 200, for example, a piston, an electric motor, or the like that is moved with respect to the cylinder by pneumatic pressure or hydraulic pressure is used.

  The cavity plate 8 is provided with arrangement holes 8a, 8a,. The arrangement hole 8a has a lower opening smaller than the upper opening. In the cavity plate 8, for example, two guide mounting holes 8b, 8b are formed on the outside of the arrangement holes 8a, 8a,.

  Guide shafts 12 and 12 are arranged in the arrangement space 4 of the fixed mold 3. The upper and lower ends of the guide shafts 12 and 12 are respectively inserted into and coupled to guide mounting holes 7 c and 7 c formed in the mounting plate 7 and guide mounting holes 8 b and 8 b formed in the cavity plate 8.

  On the guide shafts 12 and 12, a valve drive plate 13 that faces in the vertical direction is supported so as to be movable in the vertical direction.

  The valve drive plate 13 has a sprue insertion hole 13 a penetrating vertically at the center, and the sprue insertion hole 13 a is positioned directly below the nozzle insertion hole 7 a of the mounting plate 7. Supported holes 13b and 13b penetrating vertically are formed in the outer periphery of the valve drive plate 13 so as to be separated from each other in the left-right direction. The valve drive plate 13 is configured by, for example, a first coupling plate 14 and a second coupling plate 15 that are coupled vertically.

  The valve drive plate 13 is supported on the upper ends of the guide shafts 12 and 12 by inserting the guide shafts 12 and 12 into the supported holes 13b and 13b, respectively. Compression coil springs 16 and 16 are supported on the guide shafts 12 and 12 below the valve drive plate 13, respectively. Therefore, the valve drive plate 13 is urged upward by the compression coil springs 16, 16 and is pressed against the mounting plate 7 from below by the urging force of the compression coil springs 16, 16 when no downward force is applied.

  The driving force of the drive rods 11 and 11 is transmitted to the valve drive plate 13. The drive rods 11, 11 are positioned at equal intervals in the circumferential direction centering on an axis S that passes through the central portion of the valve drive plate 13 and extends in the moving direction of the valve drive plate 13. Specifically, the drive rods 11 and 11 are positioned 180 degrees apart in the circumferential direction. Three or more drive rods 11 may be provided. In this case as well, it is desirable that the plurality of drive rods 11, 11,... Be positioned at equal intervals in the circumferential direction. Further, only one drive rod 11 may be provided, but in this case, it is desirable that the drive rod 11 be supported at a position close to the central portion of the mounting plate 7.

  Gate opening / closing pins 17, 17,... Are coupled to the valve drive plate 13 in a state of being separated in the horizontal direction. The gate opening / closing pin 17 has an upper end portion provided as a coupling portion 17a and a lower end portion provided as a gate opening / closing portion 17b. The gate opening / closing pin 17 is coupled in a state in which the coupling portion 17 a is disposed inside the valve driving plate 13, and a portion other than the coupling portion 17 a protrudes downward from the valve driving plate 13.

  A manifold 18, a sprue 19, and nozzles 20, 20,... Constituting the hot runner system are arranged in the arrangement space 4 of the fixed mold 3.

  The manifold 18 is formed in a flat shape with a reduced thickness in the vertical direction, and is located between the guide shafts 12 and 12. A flow path 21 through which the molten resin flows is formed inside the manifold 18, and the flow path 21 includes an intermediate portion 21 a positioned at the center in the vertical direction, an inflow portion 21 b positioned above the intermediate portion 21 a, and an intermediate portion. It consists of the branch part 21c, 21c, ... located in the lower side of 21a.

  The intermediate portion 21a is formed as a space whose width in the horizontal direction is larger than the width in the vertical direction.

  The inflow portion 21b is formed in the central portion of the manifold 18, the upper opening is opened in the upper surface of the manifold 18, and the lower opening is communicated with the central portion of the intermediate portion 21a.

  The branch portions 21c, 21c,... Are spaced apart in the horizontal direction, and the same number as the gate opening / closing pins 17, 17,. The diameter of the branch portions 21c, 21c,... Is made larger than the diameter of the gate opening / closing pins 17, 17,. The branch portion 21 c has an upper opening communicating with the intermediate portion 21 a and a lower opening opened on the lower surface of the manifold 18.

  The manifold 18 is formed with pin support holes 18a, 18a,. The number of the pin support holes 18a, 18a,... Is the same as the number of the gate opening / closing pins 17, 17, ..., and is positioned directly above the gates 23a, 23a,.

  The manifold 18 is attached to the upper surface of the cavity plate 8 via, for example, an annular spacer 22.

  The sprue 19 is formed in a cylindrical shape extending vertically, and the internal space is formed as a resin inflow passage 19a. The sprue 19 is coupled to the upper surface of the central portion of the manifold 18, and the resin inflow passage 19 a communicates with the inflow portion 21 b of the manifold 18. The sprue 19 is inserted into the sprue insertion hole 13 a of the valve drive plate 13, and the upper end portion is inserted into the nozzle insertion hole 7 a of the mounting plate 7. A supply nozzle 100 to be inserted into the nozzle insertion hole 7 a is coupled to the sprue 19.

  The nozzles 20, 20,... Are spaced apart in the horizontal direction, and the same number as the gate opening / closing pins 17, 17,. The nozzle 20 is formed by a cylindrical portion 20a extending vertically and a flange portion 20b projecting outward from an upper end portion of the cylindrical portion 20a. The nozzle 20 has a cylindrical portion 20 a inserted into the arrangement hole 8 a of the cavity plate 8 from above, and a flange portion 20 b positioned above the cavity plate 8.

  The nozzle 20 is formed with a flow path 23 penetrating vertically. The flow path 23 is formed as a gate 23a whose lower end portion has a smaller diameter than other portions. The gate 23a is positioned substantially coincident with the lower opening of the arrangement hole 7a. The diameter of the flow path 23 is larger than the diameter of the gate opening / closing pin 17 except for the gate 23a. The diameter of the gate 23 a is substantially the same as the diameter of the gate opening / closing pin 17.

  Are connected to the lower surface of the manifold 18, and the flow paths 23, 23,... Communicate with the branch portions 21 c, 21 c,.

  .. Are arranged around the cylindrical portions 20a, 20a,... Of the nozzles 20, 20,. It arrange | positions at arrangement | positioning hole 8a, 8a, .... The nozzles 20, 20,... Are heated by the heaters 24, 24,..., Respectively, and solidification due to cooling of the molten resin flowing through the flow paths 23, 23,.

  The manifold 18 and the sprue 19 are also heated by a heater (not shown), and solidification due to cooling of the molten resin flowing through the flow passage 21 of the manifold 18 and the resin inflow passage 19a of the spru 19 is prevented.

  The gate opening / closing pins 17, 17,... Are inserted through the pin support holes 18a, 18a,. The gate opening / closing pins 17, 17,... Are inserted into the pin support holes 18a, 18a,..., And the manifolds 18 and the flow paths 23, 23,. Is inserted. The diameters of the gate opening / closing pins 17, 17,... Are smaller than the diameters of the flow paths 23, 23,. .. A space in which the molten resin flows is formed on the outer peripheral side of.

<Operation in injection mold>
Next, an operation when a molded product is formed in the injection mold 1 will be described (see FIGS. 2 to 4).

  In the injection mold 1, the movable mold 2 is moved upward with respect to the fixed mold 3, the movable mold 2 is abutted against the fixed mold 3, and convex portions 2 a, 2 a, etc. formed on the movable mold 2. And cavities 5, 5,... Are formed by the recesses 3a, 3a,... Formed in the fixed mold 3 (see FIG. 2). At this time, the valve drive plate 13 is pressed against the mounting plate 7 by the compression coil springs 16 from below, and the gate opening / closing pins 17, 17,... Are positioned at the upper moving end, and the gate opening / closing portions 17b, 17b,. Are positioned above the gates 23a, 23a,... Of the nozzles 20, 20,. Therefore, the gates 23a, 23a,... Are opened.

  When the movable die 2 is abutted against the fixed die 3 to form the cavities 5, 5,..., The molten resin 300 is supplied from the supply nozzle 100 to the sprue 19 (see FIG. 3). The molten resin 300 supplied to the sprue 19 flows through the flow path 21 of the manifold 18 from the resin inflow path 19a and is branched by the branch portions 21c, 21c,..., And the flow path 23 of the nozzles 20, 20,. , 23,... At this time, the molten resin 300 flows in the space on the outer peripheral side of the gate opening / closing pins 17, 17,... In the branch portions 21c, 21c,. When the molten resin 300 flows from the sprue 19 through the manifold 18 toward the nozzles 20, 20,..., The sprue 19, the manifold 18 and the nozzles 20, 20,. .. is heated and solidification due to cooling of the molten resin 300 is prevented.

  The molten resin 300 flows from the gates 23a, 23a, ... of the flow paths 23, 23, ... to the cavities 5, 5, ..., and into the cavities 5, 5, ..., respectively. Are filled.

  When the cavities 5, 5,... Are filled with molten resin 300, 300,..., The drive rods 11, 11 are moved downward by the drive sources 200, 200, respectively, and the valve drive plate 13 is driven by the drive rod. 11 and 11 and is moved downward against the urging force of the compression coil springs 16 and 16, and the gate opening and closing pins 17, 17... Are moved downward as the valve drive plate 13 moves to open and close the gate. The gates 23a, 23a, ... of the nozzles 20, 20, ... are closed by the portions 17b, 17b, ..., respectively (see Fig. 4). Therefore, the discharge of the molten resin 300, 300,... From the nozzles 20, 20,.

  At this time, the valve drive plate 13 is guided and moved by the guide shafts 12, 12 arranged outside the manifold 18.

  At this time, as described above, since the guide shafts 12 and 12 are disposed outside the manifold 18 in the direction orthogonal to the moving direction of the valve drive plate 13, the distance between the guide shafts 12 and 12 is increased. The inclination of the valve driving plate 13 is suppressed, the valve driving plate 13 is moved in a stable state, and the operation of the valve driving plate 13 and the gate opening / closing pins 17, 17,.

  Further, as described above, the drive rods 11 and 11 are positioned at equal intervals in the circumferential direction with the axis S as the center.

  Therefore, it becomes easy to transmit an equal driving force from the drive rods 11, 11 to the valve drive plate 13 with reference to the center portion, and the gate opening / closing pins 17, 17,... With the inclination of the valve drive plate 13 suppressed. Is moved in the axial direction, and smooth operation of the gate opening / closing pins 17, 17,... And high-precision opening / closing operation with respect to the gates 23a, 23a,. can do.

  Further, as described above, the drive rods 11 and 11 are positioned at equal intervals in the radial direction with respect to the axis S.

  Therefore, it becomes easy to transmit an equal driving force from the drive rods 11, 11 to the valve drive plate 13 with reference to the center portion, and the gate opening / closing pins 17, 17,... With the inclination of the valve drive plate 13 suppressed. Is moved in the axial direction, smoothing of the further operation of the gate opening / closing pins 17, 17,... And opening / closing of the gate opening / closing pins 17, 17,. Operation can be ensured.

  As described above, when the discharge of the molten resins 300, 300,... Into the cavities 5, 5,... Is stopped, the molten resins 300, 300,. ... is cooled and solidified.

  When the molten resins 300, 300,... Filled in the cavities 5, 5,... Are cooled and solidified, the movable mold 2 is moved downward and separated from the fixed mold 3, and the ejector pins 6, The molten resins 300, 300,... Solidified by 6,... Are respectively extruded, and the solidified molten resins 300, 300,. 5 is taken out.

<Modification of injection mold>
Next, modifications of the injection mold 1 will be described (see FIGS. 5 to 11).

  In addition, in each modification shown below, an action plate is arranged between the drive rod and the valve drive plate, and the driving force of the drive rod is transmitted to the valve drive plate via the action plate, in contrast to the above-described configuration. Only the difference. Accordingly, only the parts different from the above-described configuration will be described in detail with respect to the following modifications, and the other parts will be denoted by the same reference numerals as the same parts in the above-described configuration, and description thereof will be omitted.

  The first modification is an example in which an action plate 25 and rotating bodies 26 and 26 are provided, and one drive rod 11 is movably supported on the mounting plate 7 (see FIG. 5).

  The action plate 25 is located between the drive rod 11 and the valve drive plate 13 in the arrangement space 4 of the fixed mold 3. The action plate 25 is formed in a flat plate shape that faces in the vertical direction, is movably supported by the guide shafts 12 and 12, and is pressed by the drive rod 11 when the drive rod 11 is moved downward. An insertion hole (not shown) through which the sprue 19 is inserted is formed in the central portion of the action plate 25.

  The rotators 26 are located on the opposite side in the front-rear direction, for example, with the central portion of the valve drive plate 13 interposed therebetween, and are rotatably supported by the valve drive plate 13. For example, a bearing is used as the rotating body 26. The rotating body 26 includes a fulcrum shaft 27 extending in the horizontal direction and a rotating portion 28 that is rotated about the fulcrum shaft 27 and has a circular outer periphery.

  The rotators 26 and 26 have fulcrum shafts 27 and 27 connected to the valve drive plate 13, respectively, and the rotating portions 28 and 28 are rotated relative to the valve drive plate 13 with the fulcrum shafts 27 and 27 as fulcrums.

  The action plate 25 is in contact with the outer peripheral surfaces 28a, 28a of the rotating portions 28, 28 from above. Accordingly, the driving force of the drive rod 11 is transmitted from the action plate 25 to the rotating bodies 28 and 28, and is transmitted from the rotating bodies 28 and 28 to the valve driving plate 13.

  When the drive rod 11 is moved downward by the drive source 200, the action plate 25 is pressed by the drive rod 11 and moved downward. At this time, since the portion other than the central portion of the action plate 25 is pressed by the drive rod 11, a force is generated in the action plate 25 in a direction inclined with respect to the horizontal direction, but a force in the inclination direction generated in the action plate 25 is generated. Thus, the rotating portions 28 and 28 are rotated about the fulcrum shafts 27 and 27 (see FIG. 6). In FIG. 6, in order to facilitate understanding of the description, a state in which the action plate 25 is inclined with respect to the horizontal direction is virtually illustrated.

  Accordingly, the driving force of the drive rod 11 is transmitted to the fulcrum shafts 27, 27 of the rotating bodies 26, 26 via the action plate 25, and the component force generated directly on the fulcrum shafts 27, 27 is the fulcrum shafts 27, 27. Is applied to the valve drive plate 13 as a force in a direction of moving downward, and the valve drive plate 13 is moved in a state in which the inclination is suppressed with respect to the horizontal direction.

  In such a configuration in which one drive rod 11 is provided, the drive force of the drive rod 11 is applied to the valve drive plate 13 via the action plate 25 and the rotating bodies 26, 26, thereby providing the valve drive plate. The gate opening / closing pins 17, 17,... Are moved in the axial direction with the inclination of the gate 13 being suppressed, and the gate opening / closing pins 17, 17,. It is possible to ensure a highly accurate opening / closing operation for the gates 23a, 23a,.

  The second modified example is an example in which an action plate 29 is provided, and one drive rod 11 is movably supported on the mounting plate 7 (see FIG. 7).

  The action plate 29 is positioned between the drive rod 11 and the valve drive plate 13 in the arrangement space 4 of the fixed mold 3. The action plate 29 has a flat portion 30 formed in a flat plate shape facing in the up-down direction and transmission protrusions 31, 31 protruding downward from the flat portion 30, and the tip surfaces of the transmission protrusions 31, 31 are curved surfaces, respectively. It is formed as parts 31a and 31a. The transmission protrusions 31, 31 are located on the opposite side in the front-rear direction, for example, with the central part of the flat surface part 30 interposed therebetween.

  The action plate 29 is supported by the guide shafts 12 and 12 so that the flat portion 30 is movable, and is pressed by the drive rod 11 when the drive rod 11 is moved downward. An insertion hole (not shown) through which the sprue 19 is inserted is formed in the central portion of the plane portion 30.

  The curved surface portions 31 a and 31 a of the transmission protrusions 31 and 31 are in contact with the valve drive plate 13 from above. Accordingly, the driving force of the drive rod 11 is transmitted from the action plate 29 to the valve drive plate 13.

  When the drive rod 11 is moved downward by the drive source 200, the action plate 29 is pressed by the drive rod 11 and moved downward. At this time, since a portion other than the central portion of the action plate 29 is pressed by the drive rod 11, a force is generated in the action plate 29 in a direction inclined with respect to the horizontal direction, but a force in the inclination direction generated in the action plate 29 is generated. Thus, the transmission protrusions 31 are slid relative to the upper surface of the valve drive plate 13 (see FIG. 8). In FIG. 8, in order to facilitate understanding of the explanation, a state in which the action plate 29 is inclined with respect to the horizontal direction is virtually shown.

  Accordingly, the driving force of the drive rod 11 is transmitted to the transmission protrusions 31, 31 of the action plate 29, and the component force generated just below the transmission protrusions 31, 31 is transmitted from the transmission protrusions 31, 31 to the valve drive plate 13. The valve driving plate 13 is moved in a state in which the inclination is suppressed with respect to the horizontal direction.

  In such a configuration in which one driving rod 11 is provided, the driving force of the driving rod 11 is applied to the valve driving plate 13 via the transmission protrusions 31 of the action plate 29, thereby driving the valve. The gate opening / closing pins 17, 17,... Are moved in the axial direction in a state where the inclination of the plate 13 is suppressed, and the gate opening / closing pins 17, 17,. It is possible to ensure a highly accurate opening / closing operation with respect to the gates 23a, 23a,.

  In the second modification, the example in which the transmission protrusions 31 and 31 are in contact with the upper surface of the valve drive plate 13 has been shown. However, as shown in FIG. 9, the valve drive plate 13 has a curved concave surface. It is also possible to form 13c so that the transmission protrusions 31, 31 are in contact with the concave surface 13c.

  Thus, by forming the concave surface 13c on the valve drive plate 13 and bringing the transmission protrusions 31 and 31 into contact with the concave surface 13c of the valve drive plate 13, the distance between the valve drive plate 13 and the action plate 29 is reduced, and injection molding is performed. The metal mold 1 can be downsized.

  Also, in the above, the example in which the transmission protrusions 31 and 31 are provided on the action plate 29 has been shown, but conversely, as shown in FIG. 10, the transmission protrusions 32 and 32 are provided on the valve drive plate 13 for transmission. The curved surfaces 32 a and 32 a of the protrusions 32 and 32 may be in contact with the lower surface of the action plate 29. In this case, the driving force of the drive rod 11 is transmitted from the action plate 29 to the valve drive plate 13 having the transmission protrusions 32 and 32.

  In addition, when the transmission protrusions 32 and 32 are provided on the valve drive plate 13, a curved concave surface 29a may be formed on the action plate 29 so that the transmission protrusions 32 and 32 are in contact with the concave surface 29a. It is possible (see FIG. 11). Also in this case, the distance between the valve drive plate 13 and the action plate 29 is reduced, and the injection mold 1 can be downsized.

<Summary>
As described above, in the injection mold 1, the drive rod 11 is disposed at the outer end of the fixed mold 3, and the drive rod 200 is disposed outside the outer surface of the fixed mold 3. The driving force of the drive rod 11 is transmitted to the gate opening / closing pin 17 and the gate opening / closing pin 17 is moved in the axial direction.

  Accordingly, since the drive rod 11 is disposed at the outer end of the fixed mold 3 and the drive source 200 is disposed outside the outer surface of the fixed mold 3, the structure of the injection mold 1 can be simplified and miniaturized. Can be planned.

  In general, in an injection mold, a gate opening / closing pin and a mechanism for moving the gate opening / closing pin are arranged in a fixed mold, so that the gate opening / closing pins 17, 17,. , 17,... Are arranged on the stationary mold 3 so that the injection mold 1 can be designed without significantly changing the existing structure. Thus, it is possible to avoid a significant increase in the design cost of the injection mold 1.

  Further, in the injection mold 1, the gate opening / closing pins 17, 17,... Are provided by the pistons supported by the cylinders arranged in the axial direction of the gate opening / closing pins 17, 17,. Since it is not configured to be pressed in the axial direction, the distance (pitch) between the gate opening / closing pins 17, 17,... Does not depend on the size of the outer diameter of the cylinder, and the gate opening / closing pins 17, 17,. -The pitch between them can be reduced to further reduce the size of the injection mold 1.

  Further, the manifold 18, the sprue 19 and the nozzles 20, 20,... Constituting the hot runner system are disposed inside the fixed mold 3, and the drive source 200 is disposed outside the fixed mold 3. The influence of the heat generated in the hot runner system is less likely to occur with respect to 200, and there is no need to provide a heat blocking mechanism or a cooling mechanism for the drive source 200.

  Accordingly, since the influence of heat generated in the hot runner system hardly occurs on the drive source 200, the reliability of the operation of the drive source 200 can be improved, and a heat shut-off mechanism or cooling for the drive source 200 can be achieved. Since it is not necessary to provide a mechanism, it is possible to reduce the size and manufacturing cost of the injection mold 1.

  Furthermore, since the drive source 200 is arranged outside the fixed mold 3, the drive source 200 is not affected by the gas generated inside the injection mold 1 when the molded product 400 is molded. The reliability of the operation of the source 200, the life of the drive source 200 can be extended, and the maintainability of the drive source 200 can be improved.

  In addition, an ejector pin 6 that protrudes the molded product 400 from the movable die 2 and takes out from the cavity 5 is supported, and a valve drive plate 13 that is moved in the axial direction of the gate opening / closing pin 17 is disposed inside the fixed die 3.

  Therefore, since the ejector pin 6, the valve drive plate 13 and the gate opening / closing pin 17 that are moved in the same direction are positioned on the movable mold 2 and the fixed mold 3, respectively, the structure of the injection mold 1 is simplified. And control of each part moved in the same direction can be facilitated.

  Further, since the plurality of gate opening / closing pins 17, 17,... Are simultaneously moved by the valve driving plate 13, it is necessary to provide the driving rod 11 and the driving source 200 for each of the gate opening / closing pins 17, 17,. In addition, the structure of the injection mold 1 can be simplified and the manufacturing cost can be reduced.

  In the above, an example in which a plurality of cavities 5, 5,... Are formed when the movable mold 2 is abutted against the fixed mold 3, but in the injection mold 1, One cavity 5 may be formed when the movable mold 2 is abutted against the fixed mold 3. In this case, the molten resin is discharged from a plurality of nozzles 20, 20,... Into one cavity 5, and one molded product 400 is formed by the molten resin filled in one cavity 5.

DESCRIPTION OF SYMBOLS 1 ... Injection mold 2 ... Movable type 3 ... Fixed mold 5 ... Cavity 6 ... Ejector pin 11 ... Drive rod (drive part)
DESCRIPTION OF SYMBOLS 12 ... Guide shaft 13 ... Valve drive plate 17 ... Gate opening / closing pin 17a ... Connection part 17b ... Gate opening / closing part 18 ... Manifold 19 ... Sprue 20 ... Nozzle 21 ... Flow path 23a ... Gate 25 ... Action plate 26 ... Rotating body 27 ... Support Shaft 28a ... Outer peripheral surface 29 ... Action plate 31 ... Transmission protrusion 31a ... Curved surface part 32 ... Transmission protrusion 32a ... Curved surface part 100 ... Supply nozzle (resin supply part)
200 ... Driving source 300 ... Molten resin 400 ... Molded product

Claims (10)

An injection mold having a fixed mold and a movable mold that form a cavity filled with molten resin by being abutted against each other,
A sprue to which the molten resin is supplied from a resin supply unit;
A manifold formed in the stationary mold in which a flow path through which the molten resin flows from the sprue and the molten resin flows is formed;
A plurality of nozzles each having a gate for discharging the molten resin flowing in the flow path toward the cavity;
A plurality of gate opening / closing pins that are moved in the axial direction to open and close the gates, respectively.
A drive unit that moves the gate opening / closing pin in the axial direction and is supported by an outer end of the fixed mold;
The fixed mold is provided with a guide shaft for guiding the gate opening / closing pin in the axial direction,
The manifold and the drive unit are spaced apart in the moving direction of the gate opening / closing pin,
The manifold and the guide shaft are arranged apart from each other in a direction perpendicular to the arrangement direction of the manifold and the drive unit,
The driving unit is driven by a driving source disposed outside the outer surface of the fixed mold, and the driving force of the driving unit is transmitted to the plurality of gate opening / closing pins to move the plurality of gate opening / closing pins in the axial direction. Injection mold. The injection mold according to claim 1, wherein an ejector pin that protrudes a molded product molded in the cavity and ejects the molded product from the cavity is supported by the movable mold so as to be movable in an axial direction. A valve drive plate that is movable in the axial direction of the gate opening / closing pin in accordance with the operation of the drive unit is disposed inside the fixed mold,
3. The gate opening / closing pin is provided as a gate opening / closing portion for opening and closing the gate at one end in the axial direction, and as a coupling portion coupled to the valve drive plate at the other end in the axial direction. The mold for injection molding as described in 2. A plurality of the guide shafts are provided, and the valve drive plate is supported by the plurality of guide shafts so as to be movable in the axial direction.
The injection mold according to claim 3, wherein the plurality of guide shafts are arranged outside the manifold in a direction orthogonal to a moving direction of the valve drive plate. A spring for biasing the valve drive plate in a direction in which the gate opening / closing pin opens the gate is provided.
The injection mold according to claim 3 or 4. The spring is supported by the guide shaft
The injection mold according to claim 5. A plurality of the drive units are provided,
Wherein the plurality of drive unit, the valve driving plate according to claim 3 which is positioned at equal intervals an axis extending in the moving direction of the street the valve drive plate a central portion in the circumferential direction around the claim 4, claim 5 Or the metal mold | die for injection molding of Claim 6 . A plurality of the drive units are provided,
The plurality of driving units are positioned at equal intervals in the radial direction with reference to an axis extending in the moving direction of the valve driving plate through a central portion of the valve driving plate . The injection mold according to claim 6 or 7 . An action plate that is movable in the same direction as the valve drive plate and transmits the drive force of the drive unit is disposed between the drive unit and the valve drive plate,
A rotating body that is rotatable about a fulcrum shaft perpendicular to the axial direction of the gate opening / closing pin is supported on the valve drive plate,
The action plate is in contact with the outer peripheral surface of the rotating body;
The driving force of the driving unit is transmitted from the working plate to the valve driving plate via the rotating body. The claim 3, the claim 4, the claim 6, the claim 7, or the claim 8 . Mold for injection molding. An action plate that is movable in the same direction as the valve drive plate and transmits the drive force of the drive unit is disposed between the drive unit and the valve drive plate,
One of the action plate or the valve drive plate is provided with a transmission protrusion having a curved surface portion in contact with the valve drive plate or the action plate,
The driving force of the driving unit is transmitted from the action plate to the valve driving plate through the transmission protrusion. The claim 3, claim 4, claim 6, claim 7, or claim 8 The mold for injection molding as described.

Images