JP3643308B2 - Insert molding die and insert molding method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an insert molding die and an insert molding method suitable for use in molding a sphere such as a golf ball.
[0002]
[Prior art]
In general, when molding a golf ball, a spherical insert core molded in a separate process is held at the center of the cavity by a plurality of hold pins, and a plurality of different cavity spaces are formed between the insert core and the cavity. An insert molding die is used in which the material is filled from the branch material passage portion facing from the position. By the way, in this type of mold, the filling balance into the cavity is important, and when the filling balance is poor, the insert core is eccentric or the outgassing deteriorates, resulting in a weld defect and a high defect rate. Invoke a bug.
[0003]
Conventionally, as a mold for insert molding that improves such a filling balance, a mold in which the gate dimension (area) is mainly adjusted and the resin is uniformly filled from each gate portion has been adopted. For example, in the golf ball injection mold disclosed in Japanese Patent Application Laid-Open No. 2000-185117, by setting the average cross section of the far gate to be larger than the average cross section of the proximity gate, the injection balance of each gate is set. The injection balance is prevented from being lost due to a time lag in material injection based on the position of the gate from the supply hole.
[0004]
[Problems to be solved by the invention]
However, such a conventional insert mold has the following problems.
[0005]
First, it is difficult to adjust each gate, for example, it is necessary to repeat molding trials for adjusting each gate, which requires considerable time and man-hours and increases the cost of the mold.
[0006]
Secondly, since the filling balance is lost due to a change in the resin viscosity or the like, the versatility and stability are lacking, and the above-described various problems associated with the breaking of the filling balance cannot be avoided reliably.
[0007]
The present invention solves such a problem existing in the prior art, eliminates the need for troublesome gate adjustment that requires time and man-hours, reduces mold costs, and reduces resin viscosity. An object of the present invention is to provide a mold for insert molding and an insert molding method capable of always ensuring a filling balance without being influenced by changes and enhancing versatility and stability.
[0008]
[Means for Solving the Problems and Embodiments]
The insert molding die 1 according to the present invention constitutes a die having a plurality of branch material passage portions filled with material L from a plurality of different positions with respect to a sphere molding cavity C to be insert-molded. A valve which is attached to the end of the branch runner portion 2a constituting the branch material passage portion and which opens or closes the branch runner portion 2a ... by moving forward or backward in a direction perpendicular to the flow direction of the branch runner portion 2a ... The opening / closing part 3a ... having the body 6a ..., the driving mechanism part 4 for simultaneously opening / closing the opening / closing parts 3a ..., and by controlling the driving mechanism part 4, each opening / closing part 3a ... And a control unit 5 that opens each of the opening / closing units 3a ... when a preset opening condition is reached after the filling of the material L is started.
[0009]
Further, the insert molding method according to the present invention, when filling the material L from the branch material passage portions arranged at a plurality of different positions with respect to the sphere molding cavity C to be insert molded, Attached to the end of the branch runner portion 2a constituting each branch material passage portion, and opened or closed by moving forward or backward in a direction perpendicular to the flow direction of the branch runner portion 2a. Opening / closing sections 3a having valve bodies 6a ... are respectively attached, the opening / closing sections 3a are closed before the filling of the material L, and the material L is injected and filled up to the opening / closing sections 3a, and the filling of the material L is started. Later, when a preset opening condition is reached, the open / close portions 3a are simultaneously opened so that the cavity L is filled with the material L.
[0010]
Thus, when the material L is injected and filled into the cavity C of the mold 1, each branch runner portion 2 a... Is first closed by each opening / closing portion 3 a. Therefore, the injection-filled material L is blocked by the opening / closing parts 3a, and is temporarily accumulated before the opening / closing parts 3a. If the opening condition set in advance, for example, the pressure sensor, the temperature sensor, or the like detects that the material L is accumulated before the opening / closing portion 3a, the opening / closing portion 3a is opened at this detection timing. Thus, the accumulated material L is uniformly filled into the cavity C from each branch runner portion 2a.
[0011]
【Example】
Next, preferred embodiments according to the present invention will be given and described in detail with reference to the drawings.
[0012]
First, the structure of the insert molding die 1 according to the present embodiment will be described with reference to FIGS.
[0013]
In FIG. 1, reference numeral 1 denotes an insert mold, which is supported by a mold clamping device (not shown). In addition, Mi shown with a virtual line shows an injection device, and this injection device Mi and the mold clamping device constitute an injection molding machine. The mold 1 includes a fixed mold 1c and a movable mold 1m. The fixed mold 1c includes a stacked first fixed mold block portion 11, a second fixed mold block portion 12, and a third fixed mold block portion 13, and is movable. The mold 1m includes a first movable mold block portion 14, a second movable mold block portion 15, and a third movable mold block portion 16 that are stacked.
[0014]
P denotes a parting line surface, and a cavity C is formed in the parting line surface P. The cavity C is formed in a concave spherical shape for molding a golf ball, and is formed in half on each of the opposed surfaces of the third fixed block portion 13 and the third movable block portion 16 that become the parting line surface P. As shown in FIG. 2, a ring runner portion 2o having a ring shape is formed around the cavity C at a predetermined interval. From the inside of the ring runner portion 2o, six branch runner portions 2a, 2b, 2c, 2d, 2e, and 2f arranged at equal intervals in the circumferential direction are formed in a predetermined length in the center direction. Thereby, a plurality (six) of branched runner portions (branched material passage portions) 2a... Filling the material L from a plurality of different positions with respect to the cavity C to be insert-molded are provided. In this case, the cross section of the ring runner portion 2o is formed in a circular shape, the cross sections of the branch runner portions 2a ... are also formed in a circular shape, and the cross sections of the branch runner portions 2a ... are formed identically.
[0015]
Further, between each branch runner portion 2a... And the cavity C, six gate portions 17a, 17b, 17c, 17d, 17e, and 17f that respectively connect the tip of each branch runner portion 2a. . In this case, the cross section of each gate part 17a ... is formed in a circular shape and is formed identically. On the other hand, a nozzle touch portion 21 is formed on the outer surface of the second fixed block portion 12 and a sprue portion 22 is formed from the nozzle touch portion 21 to the parting line surface P. An introduction runner portion 23 is formed between the sprue portion 22 and the ring runner portion 2o to connect the sprue portion 22 and the ring runner portion 2o.
[0016]
On the other hand, a space portion Fc is provided between the first fixed block portion 11 and the third fixed block portion 13, and a plurality of drive cylinders 25 are disposed in the space portion Fc. A support block 26 is coupled to the tip of the piston rod of each drive cylinder 25. The rear ends of a plurality of hold pins 27 are coupled to the support block 26. Each hold pin 27 penetrates the third fixed block 13 and projects the tip into the cavity C. Further, a space Fm is provided between the first movable block 14 and the third movable block 16. Then, the piston rods of the plurality of drive cylinders 28 provided inside the third movable block portion 16 are made to face the space portion Fm. A support block 29 is coupled to the tip of the piston rod of each drive cylinder 28... And the rear ends of a plurality of hold pins 30 are coupled to the support block 29. Each hold pin 30... Penetrates through the third movable block 16 and projects the tip into the cavity C.
[0017]
Further, a plurality of drive cylinders 31 are arranged in the space Fm. A support block 32 is coupled to the piston rod of each drive cylinder 31. The rear end of the valve bodies 6 a, 6 b, 6 c, 6 d, 6 e, 6 f formed in a rod shape is coupled to the support block 32. Each of the valve bodies 6a penetrates the third movable block portion 16 and projects the tip into the end portion of the branch runner portion 2a. Each valve body 6a ... constitutes an opening / closing part 3a, 3b, 3c, 3d, 3e, 3f. As shown by a solid line in FIG. 3, if each valve body 6a ... is advanced, each branch runner part 2a ... 3 can be closed and the flow of the material L can be prevented, and as shown by phantom lines in FIG. 3, when the valve bodies 6a are retracted, the end of each branch runner 2a is opened, and the material L is opened. Can be permitted. Reference numeral 33 denotes a support block.
[0018]
On the other hand, each drive cylinder 31 is connected to a hydraulic circuit 35. The drive cylinders 31 and the hydraulic circuit 35 constitute a drive mechanism unit 4 that opens and closes the open / close units 3a. The drive cylinders 25 and the drive cylinders 28 are also connected to the hydraulic circuit 35. The hydraulic circuit 35 is connected to a control unit (controller) 5 that performs sequence control. Furthermore, the pressure sensor 36 shown in FIG. 4 and / or the temperature sensor 37 shown in FIG. 5 are attached to the ring runner portion 2o. In this case, the pressure sensor 36 includes a pressure transmission body 36x facing the inside of the ring runner portion 2o and a pressure detection element 36s for detecting the pressure received by the pressure transmission body 36x. The pressure sensor 36 (pressure detection element 36 s) and / or the temperature sensor 37 are connected to the control unit 5. 2 and 3, the pressure sensor 36 and / or the temperature sensor 37 are disposed at a position farthest from the introduction runner portion 23 in the ring runner portion 2o. Further, either one or both of the pressure sensor 36 and the temperature sensor 37 may be provided.
[0019]
Next, an insert molding method according to this embodiment using such an insert molding die 1 will be described according to the flowchart shown in FIG. 6 with reference to FIGS.
[0020]
Now, it is assumed that the mold 1 is in the mold open state. In this state, the control cylinder 5 controls the drive cylinders 25, 28,..., And the hold pins 27, 30,. In this state, the spherical insert core 41 molded in a separate process is inserted into the cavity C. Then, the movable mold 1m is raised to close the mold, and after the mold is closed, the drive cylinders 25, 28,... Are controlled by the controller 5, and the hold pins 27, 30,. Thus, the insert core 41 is held at the center position of the cavity C as shown in FIG.
[0021]
Further, after the high pressure mold clamping, the control unit 5 controls the drive mechanism unit 4 to close the open / close units 3a (step S1). That is, the drive cylinders 31 are driven, and the valve runners 2a are closed by advancing (raising) the valve bodies 6a. Then, injection filling of the material (molten resin) L is performed by the injection device Mi (step S2). The material L injected from the injection device Mi is filled in the path of the sprue part 22, the introduction runner part 23, the ring runner part 2o, each branch runner part 2a ..., but is blocked by each valve body 6a ... The material L is temporarily accumulated from the valve body 6a. This state is shown in FIG.
[0022]
On the other hand, when the preset opening condition is reached, the control unit 5 controls the drive mechanism unit 4 to open the opening / closing units 3a (steps S3 and S4). That is, the drive cylinders 31 are driven, and the valve runners 2a are opened by retracting (lowering) the valve bodies 6a. In this case, the opening condition is that the material L is completely accumulated up to the open / close sections 3a. Accordingly, the material L is filled and the filling pressure detected by the pressure sensor 36 has reached a preset set pressure, the material L is filled and the temperature detected by the temperature sensor 37 has a preset set temperature. In the case where both the pressure sensor 36 and the temperature sensor 37 are provided, the material L is filled, and the filling pressure detected by the pressure sensor 36 becomes a preset set pressure and is detected by the temperature sensor 37. The injection temperature has reached the preset injection position in the injection device Mi, the injection pressure has reached the preset pressure in the injection device Mi, etc. One or a combination of two or more can be the open conditions.
[0023]
By simultaneously opening the open / close portions 3a, the accumulated material L is filled into the cavity C simultaneously (equally) from the branch runner portions 2a (step S5). Thereby, even when the material L is filled from the branched runner portions (branched material passage portions) 2a arranged at a plurality of different positions with respect to the cavity C, the filling balance is always ensured. And, after releasing the hold pins 27 ..., 30 ... after the end conditions, a series of processing up to the pressure holding process is completed, through the cooling process, the mold opening process, the molded product taking process, etc. One molding cycle is completed (steps S6, S7). Further, when molding is performed, similar processing steps are repeated (steps S8, S1,...).
[0024]
As described above, according to the insert molding die 1 and the insert molding method according to the present embodiment, the branch runner portions 2a are each provided with the opening and closing portions 3a for opening and closing the branch runner portions 2a. Each opening / closing part 3a is closed before starting the filling of the material L, the material L is injected and filled up to the opening / closing part 3a, and each opening / closing part 3a is reached if a preset open condition is reached after the filling of the material L is started. .. Are opened at the same time, and the material L is filled in the cavity C. Therefore, the material L is uniformly filled into the cavity C from each branch runner portion 2a, and is branched at different positions with respect to the cavity C. Even when the runner portions (branch material passage portions) 2a... Are provided, the filling balance is always ensured. Therefore, unlike the conventional method, it is not necessary to repeat the molding trial for adjusting each gate, and the die cost can be reduced. In addition, since the filling balance is always secured without being affected by changes in resin viscosity, etc., versatility and stability are improved, and various problems (such as an increase in defect rate) due to the collapse of the filling balance are reliably avoided. Is done.
[0025]
Although the embodiments have been described in detail above, the present invention is not limited to such embodiments, and the details, configurations, shapes, materials, quantities, methods, etc., do not depart from the spirit of the present invention. You can change, add, or delete at will. For example, the so-called vertical injection molding machine is exemplified as the injection molding machine, but a horizontal injection molding machine can be similarly implemented. Moreover, the structure of the opening / closing part 3a ... is not limited to the example, and can be replaced by another structure having a function of opening / closing the branch material passage part. Furthermore, although the case where the opening / closing part 3a ... is attached to the end part of the branch runner part 2a ... is illustrated, it may be attached to the gate part 17a. On the other hand, the embodiment illustrates the case where the opening / closing parts 3a ... are opened under the same conditions. For example, by providing the drive cylinders 31 for individually driving the valve bodies 6a ..., the opening / closing parts 3a ... are opened. The degree (open area) and the open time (open timing) can be varied. Moreover, although the case where valve body 6a ... was distribute | arranged to one side and opened and closed was shown, you may distribute | arrange to both sides.
[0026]
【The invention's effect】
As described above, the insert molding die according to the present invention includes each branch material in a mold having a plurality of branch material passage portions filled with materials from different positions with respect to a sphere molding cavity to be insert molded. An opening / closing part attached to the end of the branch runner part constituting the passage part and having a valve body for opening and closing the branch runner part by moving forward or backward in a direction perpendicular to the flow direction of the branch runner part, and each opening and closing A drive mechanism unit that simultaneously opens and closes the drive unit, and by controlling the drive mechanism unit, each open / close unit is closed before starting the filling of the material, and a preset opening condition is reached after starting the filling of the material. The insert molding method according to the present invention is provided with a control unit for opening and closing the opening and closing unit, and by using this mold, each opening and closing unit is closed before starting the filling of the material, and the material is injected and filled up to each opening and closing unit. Both after filling start materials, open each closing part has been reached preset open condition simultaneously, due to so as to fill the material into the cavity, a marked effect as follows.
[0027]
(1) The troublesome gate adjustment that requires time and man-hours can be eliminated, and the mold cost can be reduced.
[0028]
(2) The filling balance can always be secured without being affected by changes in resin viscosity or the like, and versatility and stability can be improved.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing a part of an insert molding die according to a preferred embodiment of the present invention;
FIG. 2 is a partially enlarged sectional view taken along line XX in FIG.
3 is a cross-sectional view taken along line YY in FIG.
FIG. 4 is an enlarged vertical sectional view clearly showing a pressure sensor attached to the insert molding die,
FIG. 5 is an enlarged vertical sectional view clearly showing a temperature sensor attached to the insert molding die,
FIG. 6 is a flowchart showing a processing procedure of an insert molding method according to a preferred embodiment of the present invention;
7 is a partially enlarged cross-sectional view taken along line XX in FIG. 1, showing a state in which a material is filled in a branch runner portion by the insert molding method;
[Explanation of symbols]
1 Insert Mold 2a ... Branch Runner (Branch Material Passage)
3a ... Opening / closing part 4 Drive mechanism part 5 Control part 6a ... Valve element C Cavity L Material

Claims (2)

  In an insert molding die having a plurality of branch material passage portions filled with materials from a plurality of positions with respect to a sphere molding cavity to be insert-molded, at the end of the branch runner portion constituting each branch material passage portion And an opening / closing part having a valve body that opens and closes the branching runner part by moving forward or backward in a direction perpendicular to the flow direction of the branching runner part, and a driving mechanism part that drives the opening and closing of each opening / closing part simultaneously, By controlling this drive mechanism unit, it is provided with a control unit that closes each opening / closing unit before starting the filling of the material and opens each opening / closing unit by reaching a preset opening condition after starting the filling of the material Insert mold.   In an insert molding method in which material is filled from branch material passage portions arranged at a plurality of different positions with respect to a sphere molding cavity to be insert-molded, each branch material passage portion includes a branch runner constituting each branch material passage portion. An opening / closing part having a valve body for opening and closing the branch runner part by moving forward or backward in a direction perpendicular to the flow direction of the branch runner part, Close each open / close section, and inject and fill the material up to each open / close section, and after opening the material, if the preset open conditions are reached, open the open / close sections simultaneously to fill the cavity with the material. A characteristic insert molding method.

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