JP4394514B2 - Injection mold - Google Patents

Description

  The present invention relates to an injection mold suitable for injection molding, such as a molded product having a flat plate shape and fine processing on at least one surface thereof.

  For example, a molded product with a thin flat plate shape and fine processing on at least one side, such as a light guide plate for liquid crystal displays, IC cards, memory cards, etc., in mobile communication terminals such as mobile phones is manufactured by injection molding. In this case, it is common to perform so-called injection-compression molding including a step of performing compression after filling with a resin using an injection mold having the structure shown in FIG.

  The injection mold in the illustrated example has a fixed side mold part 91 attached to a fixed platen of an injection molding machine (not shown) and a movable side mold part 92 attached to a movable platen. Among these, the fixed-side mold part 91 faces the movable-side mold part 92 of the cavity 91b that is recessed from the parting surface 91a with the movable-side mold part 92 in the clamping direction indicated by the white arrow in the figure. The shaping surface 91c corresponding to one side of the thin flat plate-shaped molded product M is formed on the bottom surface. The movable-side mold part 92 is protruded from the parting surface 92a with the fixed-side mold part 91 in the clamping direction, and is inserted into the cavity 91b and clamped to fix the fixed-side mold part 91 of the core 92b. A shaping surface 92c corresponding to the opposite surface of the molded product M is formed on the opposite top surface. Reference numeral 93 denotes a resin P in the molding space 94 corresponding to the shape of the molded product M formed between the shaping surfaces 91c and 92c when the core 92b is inserted into the cavity 91b and clamped. Is a gate for injecting and filling [see FIGS. 6B and 6C].

  In the injection-compression molding using the injection mold, first, the movable side mold part 92 is moved in the mold clamping direction indicated by the white arrow in FIG. As shown in FIG. 6B, both mold portions 91 are inserted into the cavity 91b and then guided by moving the outer peripheral surface 92d of the core 92b and the inner peripheral surface 91d of the cavity 91b. The movable-side mold portion 92 is temporarily stopped in a state where the mold clamping (primary mold clamping) is performed until just before the parting surfaces 91a and 92a of the two-piece 92 come into contact with each other.

  Next, in this state, the resin P is injected from the gate 93 into the molding space 94 and filled, and then the movable side mold portion 92 is moved in the mold clamping direction to fill the molding space 94 with the resin. Clamping is completed while compressing P [FIG. 6 (c)]. Then, after cooling the resin P, when the movable side mold portion 92 is moved in the mold opening direction indicated by the black arrow in FIG. 6C, the mold is opened as shown in FIG. 6D. Can be taken out.

In such injection-compression molding, by compressing the resin P, the resin P can be distributed to every corner of the molding space 94 and the resin pressure can be made uniform. Therefore, as described above, a molded product M having a thin flat plate shape and at least one surface of which is a finely processed surface,
(1) Short shot due to insufficient filling of resin at the end of the molding space,
(2) Reproducibility of finely machined surface due to poor follow-up of resin to the shaping surface,
(3) Distortion of molded product due to non-uniform resin density resulting from non-uniform resin pressure, non-uniformity of refractive index and transmissivity in transparent molded product,
It can shape | mold without producing the molding defects, such as.

  However, in the injection mold shown in the figure, in the step of injecting the resin P into the molding space 94 that is primary clamped, the resin P passes through the gap between the outer peripheral surface 92d of the core 92b and the inner peripheral surface 91d of the cavity 91b. There is a problem that burrs are likely to occur due to leakage between the parting surfaces 91a and 92a before the completion of mold clamping. This is because in the illustrated injection mold structure, it is difficult to finish the clearance between the outer peripheral surface 92d of the core 92b and the inner peripheral surface 91d of the cavity 91b so as not to cause burrs.

  That is, since the injection mold shown in the figure is used with the fixed side mold part 91 attached to the fixed plate of the injection molding machine and the movable side mold part 92 attached to the movable platen, the injection mold depends on the weight of the injection mold. Both mold parts 91 and 92 are piled up by small dimensional changes such as distortion due to differences in expansion / contraction rate of each part due to own deflection, displacement of fixed and movable boards, or temperature change at the start of operation. Misalignment tends to occur between them.

  For this reason, when the clearance between the outer peripheral surface 92d of the core 92b and the inner peripheral surface 91d of the cavity 91b is finished to be small enough not to cause burrs, the direction between the mold portions 91 and 92, particularly the direction that intersects the mold clamping direction. In addition, when a positional deviation such as a rotation direction with respect to the mold clamping direction occurs, even if the positional deviation is minute, both of them are mold-molded when the core 92b is inserted into the cavity 91b. There is a risk of damage. In order to prevent this, the clearance between the outer peripheral surface 92d of the core 92b and the inner peripheral surface 91d of the cavity 91b must be increased to some extent, and as a result, burrs are likely to occur.

  Therefore, in Patent Document 1, as shown in FIG. 1 of Patent Document 1, the movable-side mold part B is held by the receiving plate 4 attached to the movable platen of the injection molding machine, and this receiving plate 4 is fixed. The movable side moving core 3 is surrounded by the movable side moving core (movable side product block) 3 whose surface facing the mold part A is a shaping surface 31 corresponding to the opposite surface of the molded product, and the receiving plate 4, A party that is held so as to be relatively movable in the mold clamping direction and the mold opening direction opposite to the movable moving core 3 and the receiving plate 4, and a surface facing the fixed side mold part A surrounds the shaping surface 31. A movable side plate 5 having a clamping surface 5a, and a primary mold clamping mechanism 7 disposed between the movable side plate 5 and the receiving plate 4 and biasing the movable side plate 5 in the mold clamping direction. It was proposed to eliminate these problems.

  In the above injection mold, first, the parting surface 5a of the movable side plate 5 is pressed against the parting surface 2a of the fixed side plate 2 by the urging force of the primary mold clamping mechanism 7 to perform primary mold clamping. In this state, the molding space C is filled with resin, and then the remaining portion of the movable side mold part B, that is, the receiving plate 4 and the movable part are movable by the clamping force of the injection molding machine exceeding the urging force of the primary clamping mechanism 7. By further moving the side moving core 3 in the mold clamping direction and completing the mold clamping while compressing the resin filled in the molding space C, the molded product is injection-compression molded.

  In the injection mold, the shaping surface 31 is disposed so as to be recessed from the parting surface 5a of the movable side plate 5 in the mold opening direction, and the primary mold clamping is performed by the parting surface 2a of the fixed side plate 2. Since this is performed by contact with the parting surface 5a of the movable side plate 5, even if a positional deviation occurs between both mold parts A and B, it is like conventional mold clamping by fitting the core and the cavity. There is no risk of squeezing and breaking.

  Further, the two parting surfaces 2a and 5a are in close contact with each other by the urging force of the primary mold clamping mechanism when the resin is filled. Moreover, the filling pressure of the resin at the time of injection molding is mainly held not by the movable side plate 5 but by the receiving plate 4 and fixed at a predetermined position before completion of mold clamping by the huge mold clamping force of the injection molding machine. Is added to the movable core 3 that has been moved. The resin pressure applied to the movable side plate 5 is a very small pressure corresponding to the projected area of the runner 2b and the gate 5b, and the primary mold clamping mechanism 7 can perform the primary mold clamping with a pressure exceeding it. The biasing force of the coil spring 71 is set. For this reason, there is no fear that both the parting surfaces 2a and 5a are opened when the resin is filled, and the resin leaks out to cause burrs.

Moreover, since the movable side plate 5 and the movable side movable core 3 that move relative to each other in the mold clamping direction at the time of compression after the resin filling are disposed on the same movable side mold part B, the positioning accuracy of both is more improved than before. Can also be increased. For this reason, even if the clearance between the two is finished to such an extent that burrs do not occur, there is no possibility that the operation of the mold will be hindered. Therefore, it is possible to prevent the resin from leaking into the gap between the two when the resin is filled by finishing the clearance between the two so small that burrs do not occur.
JP 2002-292686 A

Recently, it has been studied to use the injection mold described in Patent Document 1 for manufacturing a light guide plate of a liquid crystal display such as a personal computer or a television receiver, which is significantly larger in size than a liquid crystal display such as a mobile phone. .
However, it has been clarified that the following disadvantages occur when the injection mold is simply enlarged.

That is, in a general-purpose injection molding machine, as is well known, with the parting surfaces of the fixed side plate and the movable side plate oriented in a substantially vertical direction, the fixed side mold part is set to the fixed platen, and the movable side mold part is set to The mold is attached to the movable platen, and the movable platen is moved in a substantially horizontal direction orthogonal to the parting surface to perform injection molding while clamping and opening the mold.
However, as the light guide plate increases in size, each part constituting the injection mold increases in size and its weight also increases. In particular, the movable moving core is large and heavy because the size of the product is directly reflected. For this reason, although the movable moving core is positioned with respect to the receiving plate, it is influenced by its own weight, vibration during mold clamping and mold opening, resin filling, etc., temperature during molding There is a tendency to gradually deviate downward in the vertical direction with respect to the entire movable mold part due to expansion and contraction of each part accompanying the change.

Then, while repeating the molding operation for a long time, the movable side moving core biased downward in the vertical direction is provided so as to surround the movable side moving core, and the clearance with respect to the movable side moving core is as described above. There is a problem that so-called mold galling is caused by contact with the movable side plate which is finished small enough not to cause burrs.
Further, in a flat molded product such as a light guide plate, the gas generated during resin filling passes through the minute gap between the movable side moving core and the movable side plate surrounding it, and the entire circumference of the gap. In order to obtain a good molded product by reducing the residual gas as much as possible, it is important that the gas is discharged uniformly out of the molding space.

  However, when the movable side moving core is biased as described above, the gas is not easily discharged over the entire circumference of the gap, so that the gas tends to remain in the molding space. Then, the remaining gas as bubbles, as a liquid liquefied by resin pressure, or as a solid solidified by cooling, the shaping surface of the movable moving core, the fixed side core (fixed side product on the fixed side mold part side) Block) and adheres to the shaping surface, preventing the resin from following the shaping surface. As a result, the transfer accuracy (reproduction accuracy) of the finely machined surface is reduced, and the bubbles, liquids, and solids are in the product. There is also a problem that the refractive index and the transmissivity become non-uniform especially when mixed, especially in a transparent molded product.

  The object of the present invention is that, even if the molding operation is repeated over a long period of time, various problems associated with the bias of the movable moving core are less likely to occur, such as a light guide plate for a large liquid crystal display, which is larger than before. An object of the present invention is to provide a molding die suitable for molding a product.

The invention according to claim 1 has a fixed mold part and a movable mold part, and after the mold space is shut off from the outside and the primary mold is clamped before the mold clamping of both mold parts is completed, Is an injection mold for obtaining a molded product by completing mold clamping while compressing the filled resin, and the fixed-side mold portion has a surface facing the movable-side mold portion on one side of the molded product A fixed-side core that is a shaping surface corresponding to the fixed-side plate, a fixed-side plate that is disposed around the fixed-side core, and that faces the movable-side mold part, and is a parting surface that surrounds the shaping surface; The fixed side core and the fixed side plate are recessed with the shaping surface of the fixed side core flush with the parting surface of the fixed side plate or on the fixed side mold part side from the parting surface. The movable molds are fixed to each other so as to be disposed at positions. The movable side moving core which is held on the part side and the surface facing the shaping surface of the fixed side core is a shaping surface corresponding to the opposite surface of the molded product, and the fixed side mold part side of the receiving plate, The movable-side fixed core disposed around the movable-side movable core and the movable-side fixed core are held so as to be movable relative to the movable-side movable core and the receiving plate in the mold clamping direction and in the opposite mold opening direction. A movable side plate, a movable side plate and a receiving plate whose surface facing the parting surface of the fixed side mold part is a parting surface pressed against the parting surface of the fixed side plate The movable side plate is urged in the direction of mold clamping, and when clamping the mold, the parting surface of the movable side plate is fixed to the fixed side plate prior to completion of mold clamping of both mold parts. The fixed side And a primary mold clamping mechanism that shuts off a molding space formed between opposing shaping surfaces of the movable movable core and externally clamps the movable movable core. Regardless of the relative movement position of the movable side plate, the moving core's shaping surface is always held by the receiving plate so that it is located at a position recessed from the movable side parting surface to the movable side mold part. The movable side plate is configured to guide the movable side moving core and the movable side plate to be movable relative to the mold clamping direction while positioning the movable side moving core and the movable side plate in the direction orthogonal to the mold clamping direction. A movable side fixed core or plate member, a cylindrical guide bush fixed to one side of the movable side moving core, a rod-shaped guide post fixed to the other side and penetrating through a hollow portion of the guide bush, , With the above guide bush A rolling element interposed between the guide post and a retainer that rotatably holds the rolling element between the guide bush and the guide post, and the guide bush is moved along the guide post by the rolling of the rolling element. A guide post unit that linearly moves is provided, and further, a guide hole that penetrates in the mold clamping direction is provided on one side of the movable side fixed core or plate member that constitutes the movable side plate and the movable side moving core, On the other side, a guide post is inserted into the guide bush to assemble the guide post unit, and prior to aligning the movable side plate and the movable side moving core, these members are inserted through the guide holes. while positioned in the mold clamping direction orthogonal directions, injection mold, characterized in that a guide pin for guiding movable relative to the clamping direction A.

According to the second aspect of the present invention, the guide bush of the guide post unit is fixed to one side of the movable side fixed core and the movable side movable core, the guide post is fixed to the other side, and the guide hole is movable. Formed on one side of the side fixed core and the movable side moving core, and provided with a guide pin on the other side, the movable side fixed core and the movable side movable core are formed by the guide post unit, the guide hole, and the guide pin. The injection mold according to claim 1 , wherein the injection mold is guided in the mold clamping direction while being positioned directly in a direction orthogonal to the mold clamping direction.

  In the molding die described in Patent Document 1, as shown in FIG. 1, in the movable side mold part B, the movable side moving core 3 and the movable side plate 5 are in the through hole 51 b of the movable side plate 5. By inserting the positioning pin P2 fixed to the movable moving core 3 into the bush B1 fixed to, the guide is movably guided in the mold clamping direction while positioning in the direction orthogonal to the mold clamping direction.

However, in the guide by the positioning pin P2 and the bush B1, in order to move the movable side moving core 3 and the movable side plate 5 relatively smoothly in the mold clamping direction, the clearance between them is perpendicular to the mold clamping direction. Therefore, the positioning accuracy in the same direction cannot be sufficiently obtained.
For this reason, when the structure of the molding die is applied to a larger molding die, the large and heavy movable movable core 3 is biased downward in the vertical direction as the molding operation is repeated. In addition, various problems as described above occur.

  On the other hand, in the first aspect of the invention, the relative movement of the movable side mold portion in the mold clamping direction between the movable side plate and the movable side moving core is allowed, and the movable side plate is movable. Using a guide post unit that can maintain a clearance between the side fixed core and the movable side moving core in the direction perpendicular to the mold clamping direction to a minute value close to 0 and can withstand high loads in the radial direction. Because of the guide, even if the molding operation is repeated over a long period of time, it prevents the movable side moving core and the movable side fixed core disposed around the movable side moving core from being biased. Therefore, the clearance can always be kept good. For this reason, according to the first aspect of the present invention, the movable side moving core and the movable side fixed core can be prevented from causing mold galling even when the movable side moving core is enlarged as described above. Further, it is possible to prevent the gas from remaining and the occurrence of molding defects associated therewith.

According to the invention of claim 1, wherein the movable side fixed core or plate member constituting the movable plate, a guide hole provided on one side of the movable moving core, a guide pin provided on the other side The guide post unit is assembled by inserting the guide post into the guide bush while being inserted in advance and guided in the mold clamping direction, and the movable side plate and the movable side moving core can be matched with each other. For this reason, it is difficult to assemble the guide post unit, which is not easy because the clearance is substantially zero, and to perform mold matching between the movable side plate and the movable side moving core, which is not easy because the clearance is set to a small value close to zero. , Both can be easily performed. It is also possible to prevent the guide post unit from being damaged during assembly.

According to invention of Claim 2 , the movable side movable core and the movable side fixed core arrange | positioned surrounding the movable side movable core among the movable side plates are directly guided by the guide post unit. For this reason, the clearance between the two should be maintained even better to prevent mold galling, and the effect of preventing residual gas and the occurrence of molding defects associated therewith should be made even more effective. Can do. Further, since the movable side movable core and the movable side fixed core are directly guided by the guide hole and the guide pin when assembling and matching the guide post unit, the guide post unit may be damaged when assembled. The work of assembling and aligning the guide post unit can be further facilitated without causing mold galling during mold alignment.

FIG. 1 is a longitudinal sectional view showing an example of an embodiment of an injection mold according to the present invention, and FIG. 2 is a lateral sectional view of the injection mold.
1 and 2, the injection mold of this example includes a fixed mold part MS and a movable mold part MM. Among these, the fixed mold part MS includes a movable mold part MM. There is a fixed side core 1 whose opposing surface is a shaping surface 10 corresponding to one side of the molded product, and a concave portion 20a in which the fixed side core 1 is fitted on a surface facing the movable side mold part MM. A fixed-side plate that is disposed so as to surround the fixed-side core 1 by fitting the fixed-side core 1 to 20a, and whose surface facing the movable-side mold part MM is a parting surface 20b that surrounds the shaping surface 10. 2 are provided.

  The fixed-side core 1 is formed in a flat plate shape having a constant thickness in the mold-clamping direction indicated by white marks in both drawings, with one side facing the movable-side mold part MM being the shaping surface 10. ing. A plurality of cooling pipes 11 are embedded in the fixed core 1 in parallel to the vertical direction of the injection mold. The cooling pipe 11 functions to maintain the temperature of the shaping surface 10 within a certain range during injection molding by circulating a cooling fluid such as water supplied from an external supply source (not shown). Thus, excessive expansion and contraction of the shaping surface 10 can be suppressed, and the dimensional accuracy of the finely processed surface of the molded product corresponding to the shaping surface 10 can be improved. In addition, the resin injected into the molding space C formed between the shaping surface 10 of the fixed side core 1 and the shaping surface 40a of the movable moving core 4 is cooled as quickly as possible, and a molding cycle is performed. It also works to improve

With reference to FIG. 1, the cooling pipe 11 is connected to an opening 11 a provided on the surface 12 on the fixed mold part MS side of the fixed core 1 in the vicinity of the lower end in the drawing.
Referring to FIGS. 1 and 2, in the illustrated example, the fixed-side core 1 has a shaping surface 10 disposed on the same plane as the parting surface 20 b with respect to the recess 20 a of the fixed-side plate 2. Are fitted together. That is, the shaping surface 10 is the same as the parting surface 20b by fitting the fixed core 1 whose thickness is matched with the depth of the recess 20a so that the surface 12 contacts the bottom surface of the recess 20a. It is arranged on a plane.

  Note that the term “on the same plane” as used herein means that, for example, when the shaping surface 10 is a plane, the plane is disposed on the same plane as the parting surface 20b. In addition, when the shaping surface 10 is an uneven surface having minute convex portions or concave portions on the flat surface, it means that the flat surface is disposed on the same plane as the parting surface 20b. It is assumed that the convex portion also includes a state in which the convex portion protrudes toward the movable side mold portion MM from the parting surface 20b.

  Furthermore, when the shaping surface 10 is a concavo-convex surface having no flat surface, for example, a surface connecting the tip portions of the convex portions, a surface connecting the deepest portions of the concave portions, or an average line defined by Japanese Industrial Standards JIS B0601 This means that the principal surface virtualized by the above is arranged on the same plane as the parting surface 20b, and the minute convex portion is located on the movable side mold part MM side from the parting surface 20b as in the latter two cases. It also includes a protruding state.

In addition, although not shown in figure, the fixed side core 1 may be arrange | positioned in the position where the shaping surface 10 was dented only by the fixed dimension to the fixed side type | mold part MS side from the parting surface 20b.
The fixed side plate 2 is fixed to the first plate member 20 having the concave portion 20a and the parting surface 20b, and a surface 20g of the first plate member 20 on the side opposite to the parting surface 20b by bolts or the like (not shown). And the second plate member 21.

Of these, the first plate member 20 is formed in a flat plate shape having a constant thickness in the mold clamping direction, in which one side facing the movable mold part MM is a parting surface 20b.
Referring to FIG. 1, the first plate member 20 has a recess 20a passing through the first plate member 20 from a connection port 20d provided on the lower side surface 20c in the drawing, which intersects the parting surface 20b. A cooling pipe 20f reaching the opening 20e provided on the bottom surface is formed. A packing P1 is disposed around the opening 20e. Further, a pipe from an external supply source (not shown) is connected to the connection port 20d. Then, the fixed side core 1 is fitted into the concave portion 20a, and the opening 20e of the first plate member 20 and the opening 11a of the fixed side core 1 are made to coincide with each other with the packing P1 sandwiched between them, from the supply source. A fluid flow path reaching the cooling pipe 11 through the connection port 20d, the cooling pipe 20f, the opening 20e, and the opening 11a is configured.

  The second plate member 21 is formed in a flat plate shape whose one surface facing the movable mold part MM is a fixed surface 21a to the first plate member 20 and whose thickness in the mold clamping direction is constant. In addition, the second plate member 21 has a pair of flange portions 21d protruding in the vertical direction from the vicinity of the opposite surface 21c of the upper and lower side surfaces 21b in FIG. In the figure, only the lower flange portion 21d is shown, but a through hole 21e is formed through the thickness direction.

Although not shown, with the surface 21c of the second plate member 21 in contact with the stationary platen of the injection molding machine, a bolt is inserted into the through hole 21e, and a screw hole provided in the stationary platen. By fixing by screwing, the fixed side mold part MS is fixed to the fixed platen.
Further, in the fixed side plate 2, a center portion of the surface 21 c on the opposite side of the second plate member 21 is formed by first to third hot runner members 61 to 63, a needle 64, and a driving member 65 described below. A needle valve type hot runner 6 is configured to reach the parting surface 21a of the first plate member 20 from the sprue bush 61a provided on the needle plate.

That is, referring to FIG. 2, a concave portion 21f is formed in the central portion of the surface 21c of the second plate member 21 so as to be recessed toward the movable side mold portion MM, and from the center of the bottom portion of the concave portion 21f. A first hot runner member 61 is disposed toward the movable mold part MM side.
The first hot runner member 61 has one end surface facing the recess 21f as a sprue bush portion 61a to which the nozzle of the injection molding machine is pressed, and the sprue bush portion 61a is directed from the sprue bush portion 61a to the movable side mold portion MM The cylinder 61c is formed with a resin flow path 61b extending in a direction parallel to the mold clamping direction, and the heater 61d surrounds the cylinder 61c and heats the resin in the flow path 61b. .

  Further, the opposite surface 20g of the first plate member 20 and the fixed surface 21a of the second plate member 21 are respectively combined with the both surfaces 20g and 21a to form the first plate member 20 and the second plate member 21. Recesses 20h and 21g are formed so as to coincide with each other when fixed, and a first hot runner member 61 connected to the first hot runner member 61 is formed in a cavity formed at the interface between both plates 20 and 21 by the recesses 20h and 21g. Two hot runner members 62 are accommodated.

  The second hot runner member 62 has a first hot runner member 61 connected to a side surface on one end side, a third hot runner member 63 described below connected to the other end side, and a resin flow path inside. A cylindrical body 62b is formed which is connected to 61b and is formed with a resin flow path 62a extending in a direction orthogonal to the clamping direction and extending in front of the fixed side plate 2 in the drawing. Although not shown in the figure, a heater for heating the resin in the flow path 62a is embedded in the cylindrical body 62b.

  The third hot runner member 63 is connected to the resin flow path 62a on the other end side of the second hot runner member 62, and extends in a direction parallel to the clamping direction toward the movable side mold part MM. A cylinder 63b in which a resin flow path 63a reaching the parting surface 21a surrounding the outer periphery of the cylinder 63b is formed, and a heater 63c for surrounding the cylinder 63b and heating the resin in the flow path 63a. .

Further, a reduced diameter portion 63e having a reduced inner diameter is formed inside the opening 63d to the parting surface 21a of the flow path 63a. The reduced diameter portion 63e has an inner diameter of the reduced diameter portion 63e. A needle 64 having a substantially matching outer diameter is inserted.
The needle 64 is driven in a direction parallel to the mold clamping direction by a driving member 65 provided in the second plate member 21. Specifically, the needle 64 is inserted through the reduced diameter portion 63e of the flow path 63a and closed the flow path 63a as shown in FIG. 2 by the drive member 65 in accordance with the molding operation of the injection molding machine, It is driven between two states that are retracted in the mold clamping direction and pulled out from the reduced diameter portion 63e to open the flow path 63a.

  More specifically, the needle 64 reaches the mold clamping process after the mold opening process and the molded product take-out process after the injection molding process is completed, and until the next injection molding process starts after the mold clamping is completed. In order to prevent the resin in a flow state in the hot runner 6 from flowing out from the opening 63d, as shown in FIG. 2, the resin is inserted into the reduced diameter portion 63e of the flow path 63a to close the flow path 63a. The needle 64 is formed between the shaping surface 10 of the fixed-side core 1 and the shaping surface 40a of the movable moving core 4 through the hot runner 6 during injection molding after mold clamping. In order to inject into the molding space C, it retracts in the mold clamping direction and is pulled out from the reduced diameter portion 63e to open the flow path 63a.

  The driving member 65 for driving is a sleeve 65a that holds the needle 64, and a piston that extends from the outer periphery of the sleeve 65a in a flange shape outward in the direction orthogonal to the driving direction of the needle 64 along the clamping direction. A member 65b, a cylinder member 65c that accommodates the piston member 65b so as to be movable in the driving direction of the needle 64 along the mold clamping direction, and a pipe 65d for injecting fluid such as compressed air into the cylinder member 65c. . The pipe 65d extends from the cylinder member 65c to a connection port 65e provided on the side surface 21h on the near side in the drawing of the second plate member 21, and this connection port 65e is supplied with an external fluid supply source (not shown). Piping is connected.

In the state shown in FIG. 2, when a fluid such as compressed air is supplied from the supply source to the cylinder member 65c through the pipe 65d and the piston member 65b is moved backward in the mold clamping direction, the needle 64 is pulled from the reduced diameter portion 63e. The flow path 63a is opened by being pulled out.
Further, a through hole 65f reaching the rear end surface of the piston member 65b is formed on the surface 21c on the opposite side of the second plate member 21, and although not shown, a protruding member provided on the stationary platen of the injection molding machine However, it is arrange | positioned so that it may contact | abut to the rear-end surface of piston member 65b retreated in the mold clamping direction. When the protruding member is protruded in the mold opening direction and the piston member 65b retracted in the mold clamping direction is moved in the same direction with the flow path 63a opened as described above, the needle 64 is reduced in diameter. 2 is returned to the state of FIG. 2 in which the flow path 63a is closed, and the resin in a fluid state in the hot runner 6 is prevented from flowing out from the opening 63d.

  1 and 2, the movable side mold part MM is held on the receiving plate 3 and the fixed side mold part MS side of the receiving plate 3, and the surface facing the fixed side mold part MS is The movable side moving core 4 having a shaping surface 40a corresponding to the opposite surface of the molded product, and an annular shape surrounding the movable side moving core 4, are formed on the fixed side mold part MS side of the receiving plate 3 in the movable side movement. A surface facing the core 4 and the receiving plate 3 so as to be relatively movable in a mold clamping direction indicated by a white arrow and a mold opening direction opposite to the core 4 and the receiving plate 3 and facing the fixed side mold part MS, The movable side plate 5 made into the parting surface 50a surrounding the shaping surface 40a is provided.

1 and 2 show that the movable side moving core 4 is brought into contact with the surface 30a of the receiving plate 3 on the fixed mold part MS side, and the movable side plate 5 is moved to the receiving plate 3 and the movable plate. A primary mold clamping state is shown in which the parting surface 50a is protruded in the mold clamping direction with respect to the side moving core 4 and the parting surface 50a is brought into contact with the parting surface 20b of the fixed side core 2.
The receiving plate 3 has a flat plate-like first plate member 30 that holds the movable side moving core 4 and the movable side plate 5 on the surface 30a on the fixed side mold part MS side and has a constant thickness in the mold clamping direction. It consists of a flat plate-like second plate member 31 that is fixed to the opposite surface 30b of the first plate member 30 with bolts B1 and that has a constant thickness in the mold clamping direction.

Referring to FIG. 1, a through hole 30c is formed in the central portion of the first plate member 30 so as to penetrate the thickness direction, and the movable-side moving core 4 is received in the through hole 30c. 3 is accommodated in the mold clamping direction and the mold opening direction opposite to the mold clamping direction.
3 is a longitudinal sectional view showing the state of the injection mold when the mold clamping is completed, FIG. 4 is a longitudinal sectional view showing a state when the mold opening is started, and FIG. 5 is a view after the mold opening. It is sectional drawing of the vertical direction which shows a state.

  Referring to FIGS. 1 to 5, the moving mechanism A is configured so that the movable side moving core 4 is fixed to the surface 30 a of the receiving plate 3 on the fixed mold part MS side during primary clamping and clamping as described above. The state in which the movable side moving core 4 is protruded from the receiving plate 3 in the mold clamping direction (FIG. 4). As shown in FIG. 5, it functions to facilitate removal of the molded product. The moving mechanism A includes an air cylinder A1 driven by compressed air supplied from an external driving source (not shown), and a surface 40b on the receiving plate 3 side of the movable moving core 4 opposite to the shaping surface 40a. And a pin A2 projecting in the mold opening direction, an axis A1a of the air cylinder A1, and a connecting member A3 connecting the pin A2.

  Referring to FIG. 1, a stopper S <b> 1 projecting in the mold opening direction from the surface 51 b of the movable side mold part MM side of the movable side plate 5 below the through hole 30 c of the first plate member 30 in the drawing. A through hole 30d through which the base S1a is inserted is formed so as to penetrate the thickness direction. Further, a concave portion 30d for receiving the guide post unit 7 and a concave portion 30e for receiving the flange portion S2b of the stopper S2 are formed on the surface 30a on the fixed side mold portion B side of the first plate member 30. Has been.

  The second plate member 31 is formed in a flat plate shape in which one surface facing the fixed-side mold part MS is a fixed surface 31a to the first plate member 30 and the thickness in the mold clamping direction is constant. In addition, a pair of flange portions 31b project from the second plate member 31 in the vertical direction in FIG. 1, and in the drawing, only the lower flange portion 31b is illustrated, but the thickness direction penetrates the second plate member 31. Thus, a through hole 31c is formed.

Although not shown, the second plate member 31 is movable by inserting a bolt into the through hole 31c with the surface 31d opposite to the fixed surface 31 in contact with the movable platen of the injection molding machine. The movable side mold part MM is fixed to the movable platen by screwing into a screw hole provided in the plate and tightening.
Referring to FIG. 1, the movable-side moving core 4 includes a main body portion 40 formed in a flat plate shape having a shaping surface 40 a on one side facing the fixed-side mold portion MS and having a constant thickness in the clamping direction. The main body 40 has a pair of flange portions 41 projecting in the vertical direction from the vicinity of the surface 40b opposite to the shaping surface 40a side of the side surface 40c.

  With reference to FIGS. 1 and 2, a plurality of cooling pipes 42 are embedded in the movable side moving core 4 in the vicinity of the shaping surface 40a in parallel with the vertical direction of the injection mold. The cooling pipe 42 functions to maintain the temperature of the shaping surface 40a within a certain range during injection molding by circulating a cooling fluid such as water supplied from an external supply source (not shown). Thus, excessive expansion and contraction of the shaping surface 40a can be suppressed, and the dimensional accuracy of the finely processed surface corresponding to the shaping surface 40a of the molded product can be improved. In addition, the resin injected into the molding space C formed between the shaping surface 10 of the fixed side core 1 and the shaping surface 40a of the movable moving core 4 is cooled as quickly as possible, and a molding cycle is performed. It also works to improve

  With reference to FIG. 1, a through hole 41 a is formed in the upper flange portion 41 of the movable side moving core 4 so as to penetrate the thickness direction thereof, and a tube of the guide post unit 7 is formed in the through hole 41 a. A guide bush 70 is inserted and fixed. Further, the lower flange portion 41 penetrates the thickness direction in which the base portion S2a of the stopper S2 protruding from the surface 51b of the movable side mold portion MM side of the movable side plate 5 in the mold opening direction is inserted. A through hole 41b is formed.

Further, the above-described pin A2 protrudes from the surface 40b of the movable product block 4 in the mold opening direction.
Referring to FIGS. 1 and 2, the movable side plate 5 is an annular shape having a through hole 50 b through which the main portion 40 of the movable side moving core 4 is inserted, and has a flat plate shape with a constant thickness in the mold clamping direction. The movable side fixed part which is formed and the surface facing the fixed side mold part MS is the parting surface 50a and the inner peripheral surface of the through hole 50b is a shaping surface corresponding to the outer peripheral side surface of the molded product. The core 50 is formed in a flat plate shape having a constant thickness in the mold clamping direction, and has a recess 51a in which the movable side fixed core 50 is fitted on the surface 51c on the fixed side mold part MS side. It consists of a plate member 51 for holding the fixed core 50. The movable side fixed core 50 and the plate member 51 are fixed to each other by a bolt (not shown).

  Referring to FIG. 1, a portion of movable side fixed core 50 corresponding to upper flange portion 41 in the drawing is formed with a through hole 50c penetrating in the thickness direction. In a state where the base portion 71a of the guide post 71 of the post unit 7 is inserted and the main body portion 71b protrudes in the direction of the receiving plate 3 from the surface 50d of the movable side fixed core 50 opposite to the parting surface 50a. It is fixed.

  Specifically, the through hole 50c includes a through hole body 50e having an inner diameter corresponding to the outer diameter of the base 71a of the guide post 71 on the receiving plate 3 side, and an enlarged diameter part 50f having a larger inner diameter on the stationary mold part MS side. Has been. Further, a flange portion 71c extending outward in the direction orthogonal to the axial direction of the guide post 71 is formed at a boundary portion between the base portion 71a and the main portion 71b of the guide post 71, and is fixed from the flange portion 71c. The length in the axial direction of the base portion 71a on the side mold portion MS side coincides with the length in the thickness direction of the movable side fixed core 50 of the through hole body 50e of the through hole 50c, or is formed slightly shorter. Yes. Furthermore, a screw hole 71d into which the bolt B3 is screwed is formed on the end surface of the base 71a on the fixed mold part MS side.

  Then, the base 71a of the guide post 71 is inserted into the through hole main body 50e from the receiving plate 3 side, and the outer diameter is larger than the outer diameter of the base 71a from the opposite enlarged diameter portion 50f side. By inserting a stopper 72 smaller than the inner diameter of the diameter portion 50f, inserting a bolt B3 into a through hole 72a formed at the center of the stopper 72, screwing it into a screw hole 71d, and tightening the guide post 71, The portion 71b is fixed in a state of protruding from the surface 50d of the movable side fixed core 50 on the side opposite to the parting surface 50a in the direction of the receiving plate 3.

  The guide post unit 7 is interposed between the guide post 71, the previous guide bush 70, and between these, specifically, the outer peripheral surface of the main portion 71b of the guide post 71 and the inner peripheral surface of the guide bush 70. A plurality of rolling elements 73 and a retainer 74 that rotatably holds the rolling elements 73 therebetween. Further, a coil spring 75 is interposed between the retainer 74 and the flange portion 71c of the guide post 71 so as to be externally inserted into the main portion 71b of the guide post 71, and the guide bush of the retainer 74 is urged by the biasing force. The relative position with respect to 70 is always kept constant to prevent the retainer 74 from falling off.

According to the guide post unit 7, the rolling element 73 rolls between the guide bush 70 and the guide post 71, so that the position of the guide bush 70 in the direction orthogonal to the axis of the guide post 71 is always constant. The guide bush 70 can be linearly moved along the axis of the guide post 71 while maintaining the above.
For this reason, the guide post unit 7 is used to directly guide the movable side movable core 4 and the movable side fixed core 50 of the movable side plate 5, so that both of them are orthogonal to the mold clamping direction. It is possible to relatively move both in the mold clamping direction while maintaining the clearance in the direction at a minute value close to zero. Moreover, in the guide post unit 7, a roller is usually used as the rolling element 73 and can withstand a high load in the radial direction, so that the movable movable core 4 is enlarged as described above, and its weight is increased. Even if it becomes large, the above-mentioned clearance can be stably maintained.

Therefore, the clearance between the movable side movable core 4 and the movable side fixed core 50, that is, between the side surface 40 c of the main portion 40 of the movable side movable core 4 and the inner peripheral surface of the through hole 50 b of the movable side fixed core 50. It is possible to maintain a good clearance and prevent the movable-side movable core 4 and the movable-side movable core 50 from causing mold galling, and it is possible to prevent the gas from remaining and the occurrence of molding defects associated therewith.

  Referring to FIGS. 1 and 2, the plate member 51 has the concave portion 51a in which the movable side fixed core 50 is fitted on the surface 51c on the fixed side mold portion MS side as described above, and the surface on the opposite side. 51 b has a recess 51 d into which the flange portion 41 of the movable moving core 4 is fitted, and passes through both the recesses 51 a and 51 d in the thickness direction so that the main portion 40 of the movable moving core 4 is inserted. A hole 51e is provided.

  Referring to FIG. 1, a portion of the plate member 51 corresponding to the through hole 50 c includes, in the guide post unit 7, a base portion of a main portion 71 b of a guide post 71 in which a flange portion 71 c is formed, and an outer periphery thereof. A through hole 51f for receiving the coil spring 75 externally inserted in the through hole is formed penetrating in the thickness direction. The through holes 51f are formed so that the inner diameter thereof is larger than the outer diameters of these members so as not to restrict the free movement of the coil spring 75 and the retainer 74 in the mold clamping direction (the axial direction of the guide post 71). Has been.

  As described above, the stopper S1 protrudes from the surface 51b in the mold opening direction on the surface 51b of the plate member 51 on the movable mold part MM side. The stopper S1 is provided with a flange portion S1b that extends outward in the direction intersecting with the mold opening direction at the tip of the base S1a that protrudes through the through hole 30d and protrudes toward the mold opening direction. The mold clamping direction of the movable plate 5 with respect to the receiving plate 3 is caused when the portion S1b and the surface 30b of the first plate member 30 around the through hole 30d abut each other in the primary mold clamping state of FIG. Regulates further movement to.

  Further, a stopper S2 protrudes from the bottom surface 51g in the mold opening direction on the bottom surface 51g of the concave portion 51d of the plate member 51 on the movable mold part MM side. The stopper S2 is provided with a flange portion S2b that extends outward in the direction intersecting with the mold opening direction at the tip of the base S2a that protrudes through the through hole 41b and protrudes toward the mold opening direction. The part S2b and the surface 40b around the through hole 41b of the movable side moving core 4 abut on each other in the primary mold clamping state of FIG. Restricts further movement in the tightening direction.

Referring to FIG. 1, a guide hole 41c is formed in the lower flange 41 of the movable moving core 4 so as to penetrate the thickness direction thereof. Further, through holes 30k and 31f are formed in the first plate member 30 and the second plate member 31 of the receiving plate 3 so as to communicate with the guide hole 41c and penetrate in the thickness direction, respectively.
Further, through holes 50h and 51i are formed in the movable side fixed core 50 and the plate member 51 of the movable side plate 5 through the thickness direction at positions corresponding to the guide holes 41c. The base portion of the guide pin P3 is inserted through 50h and 51i, and is fixed in a state in which the tip side protrudes in the direction of the receiving plate 3.

  The guide pin P3 is inserted into the guide hole 41c before the guide post 71 is inserted into the guide bush 70 to assemble the guide post unit 7 and the movable plate 5 and the movable core 4 are matched. These members are for guiding the members so as to be relatively movable in the mold clamping direction while positioning them in a direction orthogonal to the mold clamping direction, and their tips are received from the tips of the guide posts 71 of the guide post unit 7. It protrudes on the plate 3 side.

  When the guide post unit 7 is assembled and the movable plate 5 and the movable core 4 are matched, the guide post 71 of the guide post unit 7 is inserted into the guide bush 70 before the guide post 71 is inserted. The pin P3 is inserted into the guide hole 41c, and the movable side plate 5 and the movable side moving core 4 are guided. The guide post unit 7 is assembled by inserting the guide post 71 into the guide bush 70 while guiding the movable plate 5 and the movable movable core 4 in the mold clamping direction by the guide hole 41c and the guide pin P3. The main portion 40 of the movable movable core 4 is inserted into the through hole 50b of the movable fixed core 50 while guiding the movable plate 5 and the movable movable core 4 in the mold clamping direction by the assembled guide post unit 7. The movable side plate 5 and the movable side moving core 4 can be mold-matched by being inserted. For this reason, it is possible to easily assemble and mold the guide post unit 7. Further, it is possible to prevent the guide post unit 7 from being damaged during assembly.

  That is, the clearance between the guide bush 70 and the guide post 71 of the guide post unit 7 is set to almost zero via the rolling elements 73, and the clearance between the movable movable core 4 and the movable fixed core 50 is zero. Since the operation of assembling these members almost simultaneously without any guides requires extremely high skill, the movable side plate 5 is formed by the guide holes 41c and the guide pins P3. If the work is performed while guiding the movable core 4 and the movable core 4 in the mold clamping direction, the work of assembling the guide post unit 7 and mold matching can be easily performed, and the guide post unit 7 is damaged. This can be prevented.

  The guide by the guide hole 41c and the guide pin P3 only needs to function until the guide post 71 is inserted into the guide bush 70 in the first stage of mold matching, as is apparent from the mold matching process. When the main portion 40 of the movable movable core 4 is inserted into the through hole 50b of the movable fixed core 50 in the later stage of mold matching, the guide post unit 7 is assembled by inserting the guide post 71 into the guide bush 70. This is because the movable side moving core 4 and the movable side plate 5 are guided. Therefore, the clearance between the inner diameter of the guide hole 41c and the outer diameter of the guide pin P3 can be made relatively large so as not to prevent the guide post unit 7 from guiding in the mold clamping direction.

Referring to FIG. 2, a runner 50 g that connects the opening 63 d and the molding space C is formed in a part of the parting surface 50 a of the movable side fixed core 50 corresponding to the opening 63 d of the hot runner 6. ing. The hot runner 6 and the runner 50 g constitute a semi-hot runner.
Further, a through hole 52 is formed in the runner 50g so as to penetrate the movable side fixed core 50 and the plate member 51 of the movable side plate 5 in the thickness direction at a position facing the opening 63d. The first plate member 30 of the receiving plate 3 is connected to the through hole 52 and penetrates in the thickness direction to form a through hole 30f, and the protruding pin D1 is inserted into the through holes 30f and 52. Has been.

  The protrusion pin D1 has a base end portion on the movable side mold portion MM side within the recess 30g provided on the surface 30b side of the first plate member 30 by the guide pin D2 and the bush D3, and the guide pin D4 and the first pin D4. The plate plate 30 is fixed to a protruding plate D5 supported so as to be movable in the mold clamping direction and the mold opening direction by a through hole 30h formed so as to penetrate in the thickness direction of the one plate member 30. A coil spring D6 is interposed between the protruding plate D5 and the recess 30g of the first plate member 30 so as to be extrapolated by the guide pin D4. Further, the second plate member 31 of the receiving plate 3 is formed with a through hole 31e penetrating in the thickness direction thereof and communicating with the recess 30g, and is a protrusion protruding from the protruding plate D5 in the mold opening direction. D7 is inserted into the through-hole 31e, and is arranged so that a protruding member provided on the movable platen of the injection molding machine is in contact with the tip end in the mold opening direction.

  The protruding pin D1 is disposed at the position shown in FIG. 2 until it reaches the mold opening process from the mold clamping process to the injection molding process. After the mold opening or almost simultaneously with the mold opening, the projecting member is projected in the mold clamping direction, and the projecting pin D1 is projected in the mold clamping direction via the projection D7 and the projecting plate D5. The filled resin is released from the movable side mold part MM together with the molded product formed by filling the resin in the molding space C.

Similarly, referring to FIG. 2, in the first plate member 30 of the receiving plate 3, a through hole 30 i is formed in the vicinity of the upper end portion in the drawing so as to penetrate the thickness direction. In a state where the portion is inserted, the guide pin G1 is fixed with the tip portion protruding to the fixed mold portion MS side.
Further, a through hole 51h is formed at a position corresponding to the guide pin G1 of the plate member 51 in the movable side plate 5, and the guide pin G1 is clamped and opened in the through hole 51h. A sleeve G2 for guiding is provided. Further, a recess 20i is formed at a position corresponding to the through hole 51h of the parting surface 20b of the first plate member 20 in the fixed side plate 2, and the guide pin G1 is clamped in the recess 20i. A sleeve G3 for guiding in the direction and the mold opening direction is provided.

These guide pins G1 and sleeves G2 and G3 function to align the movable side mold part MM with respect to the fixed side mold part MS during mold clamping and mold opening.
Further, referring to FIG. 2, a through hole 30 j is formed on the lower side of the first plate member 30 of the receiving plate 3 below the guide pin G <b> 1 so as to penetrate the thickness direction. In order to perform primary mold clamping, a primary mold clamping mechanism H that urges the movable side plate 5 to protrude from the receiving plate 3 in the mold clamping direction is provided.

The primary mold clamping mechanism H is embedded in a portion of the surface 51b of the plate member 51 facing the through hole 30j of the gas spring H1 and the movable side plate 5, and the shaft H2 of the gas spring H1 is brought into contact therewith, It comprises a receiving plate H3 for receiving a biasing force from the gas spring H1.
The injection molding method using the above injection mold is generally performed according to the following procedure.
First, referring to FIGS. 1 and 2, the movable platen MM is moved in the mold clamping direction indicated by the white arrow in both drawings by moving the movable platen of the injection molding machine in the mold clamping direction. As shown in both figures, before the mold clamping is completed, the parting surface 50a of the movable plate 5 is brought into pressure contact with the parting surface 20b of the fixed plate 2 by the urging force of the primary mold clamping mechanism H. Tighten the next mold.

At this time, the movable moving core 4 operates the moving mechanism A in the direction indicated by the solid line arrow in FIG. 1 to move backward in the mold clamping direction, so that the surface 40 b of the movable moving core 4 is moved to the receiving plate 3. It is moved to a position in contact with the surface 30a. In this state, the thickness of the molding space C formed between the fixed side core 1 and the movable side moving core 3 is set larger than the thickness of the actual molded product.
Next, the mold clamping is stopped, and although not shown, the injection unit of the injection molding machine is advanced to connect the nozzle at the tip of the injection unit to the sprue bush 61a, and from the supply source (not shown) to the cylinder member 65c through the pipe 65d. A fluid such as compressed air is supplied to the piston member 65b so as to retract the piston member 65b in the mold clamping direction, thereby pulling out the needle 64 from the reduced diameter portion 63e and opening the flow path 63a. The resin is injected into the molding space C through 50 g and filled.

  At this time, the resin filling pressure is applied to both the product blocks 1, 4 and the movable plate 5, but the fixed core 1 is moved from behind by the fixed plate of the injection molding machine through the fixed plate 2. It is supported. The movable moving core 4 is supported from behind by a movable plate of an injection molding machine through a receiving plate 3. For this reason, the huge mold clamping force of the injection molding machine is applied to both the product blocks 1 and 3, and there is no possibility of mold opening.

Moreover, since the movable side moving core 4 and the movable side plate 5 have finished the clearance of the outer peripheral surface 40b and the inner peripheral surface 50b which are rubbed together so that a burr | flash does not arise, between the both surfaces 40b and 50b. There is no risk of burrs due to resin leaking into the gaps.
Further, the filling pressure applied to the movable side plate 5 is very small for the projected area of the runner 50g in the direction perpendicular to the mold clamping direction, and the parting surfaces 20b, 50a of the fixed side plate 2 and the movable side plate 5 are the same. Is pressed without a gap by the urging force of the primary mold clamping mechanism H exceeding that, and there is no possibility of mold opening or burring between the plates 2 and 5.

Next, referring to FIG. 3, by moving the movable platen of the injection molding machine in the mold clamping direction, the movable side mold part MM is further moved in the mold clamping direction, and the resin P filled in the molding space C is filled. Complete clamping while compressing.
During this compression, the movable core 4 receives the clamping force directly from the movable plate of the injection molding machine via the receiving plate 3 with its surface 40b in contact with the surface 30a of the receiving plate 3. Thus, the resin P in the molding space C is compressed. By this compression, the resin P can be distributed to every corner of the molding space C and the resin pressure can be made uniform, so there is no short shot, reproducibility of the finely processed surface, distortion of the molded product, etc. A molded product that does not cause burrs is obtained.

  The molding in the mold clamping completed state of FIG. 3 in which the fixed side plate 2 constituting the fixed side mold part MS, the movable side plate 5 and the receiving plate 3 constituting the movable side mold part MM are all brought into close contact with each other without gaps. Theoretically, the thickness of the space C should ideally match the design thickness of the actual molded product. However, the thickness of the molding space C is set to be slightly smaller than the design thickness of the actual molded product, and the thickness of the molding space C at the time of molding is adjusted at the stop position of the movable platen. preferable. In this way, since the thickness of the molded product can be arbitrarily finely adjusted, for example, a molded product having a predetermined thickness can be manufactured in a flexible manner corresponding to expansion and contraction of the mold.

Next, referring to FIG. 4, after cooling the resin P, the moving mechanism A is operated in the opposite direction as shown by the solid line arrow in the figure to clamp the movable moving core 4. While pressing in the direction, the movable side mold part MM is moved in the mold opening direction to open the mold.
Then, while the movable plate 5 is kept in pressure contact with the fixed plate 2 by the urging force of the primary mold clamping mechanism H, the movable moving core 4 is prevented from moving backward by the pressing force of the moving mechanism A. Then, the receiving plate 3 opens the mold while remaining in the mold clamping position.

Next, referring to FIG. 5, after the movable side mold part MM is further opened, although not shown, when the ejection pin D1 is projected in the mold clamping direction, the molded product M and the runner 50g The filled resin is released from the movable side mold part MM and taken out from between the molds.
After the removal of the molded product M is completed, the next molding process can be started by returning to FIGS. 1 and 2 again and performing primary mold clamping.

  As described above in detail, according to the injection mold of the present invention, in particular, large shots such as light guide plates of liquid crystal displays such as personal computers and television receivers, short shots, reproducibility of finely processed surfaces, molding Good injection-compression molding can be performed without causing distortion of the product and burr. At this time, the primary mold clamping and the mold clamping can be performed while guiding the movable plate 5 directly with respect to the movable movable core 4 by the guide post unit 7 as a guide member. Even if the molding operation is repeated over a period of time and the movable side moving core 4 is biased, it is possible to prevent mold galling between the two, and it is possible to prevent residual gas and the resulting molding failure. Can be prevented.

The configuration of the present invention is not limited to the example of the figure described above.
For example, the guide post unit 7 most preferably positions the movable side movable core 4 and the movable side fixed core 50 directly as shown in the example of the figure, but the movable side movable core 4 and the plate member 51 are positioned. The movable side movable core 4 and the movable side fixed core 50 may be positioned indirectly by positioning them. Similarly, it is most preferable that the guide hole 41c and the guide pin P3 position the movable side movable core 4 and the movable side fixed core 50 directly as shown in the example of the figure. The movable side movable core 4 and the movable side fixed core 50 may be positioned indirectly by positioning the plate 4 and the plate member 51.

  Moreover, in the example of the figure, the uneven surface corresponding to the finely processed surface of the molded product is formed directly on the shaping surface 10 of the fixed core 1 and the shaping surface 40a of the movable core 4. For example, both the shaping surfaces 10 and 40a may be smooth surfaces, and a metal foil stamper having an uneven surface or the like formed on the smooth surfaces may be attached in a replaceable state. In this case, by changing the stamper, molded products having various finely processed surfaces can be manufactured with one injection mold. Further, when the uneven surface or the like is damaged or worn, the shaped surface can always be maintained in a good state by replacing with a new stamper.

  Further, in the example of the figure, the surface of the movable side fixed core 50 that faces the fixed side mold part MS is a parting surface 50a, and the main part 40 of the movable side movable core 4 of the movable side fixed core 50 is inserted. The inner peripheral surface of the through-hole 50b is a shaping surface corresponding to the outer peripheral side surface of the molded product. However, for example, a movable side fixed core 50 is provided with a side core movable in a direction orthogonal to the mold clamping direction, and the surface of the side core that faces the fixed side mold part MS is defined as a parting surface 50a. The inner peripheral surface of the side core facing the molding space C may be a shaping surface corresponding to the outer peripheral side surface of the molded product.

As the primary clamping mechanism H, a mechanism using various members having the same type of function can be adopted instead of the gas spring H1 shown in the drawing.
Similarly, as the moving mechanism A, one using various members having the same type of function can be adopted. Further, the moving mechanism A and the like may be provided outside the mold.
The present invention is not limited to injection-compression molding such as a light guide plate for a liquid crystal display, and can be applied to molding of various other flat molded products.

  In addition, various design changes can be made without departing from the scope of the present invention.

It is sectional drawing of the vertical direction which shows an example of embodiment of the injection mold of this invention. It is sectional drawing of the horizontal direction of the said injection mold. It is sectional drawing of the vertical direction which shows the state at the time of the completion of mold clamping of the said injection mold. It is sectional drawing of the vertical direction which shows the state at the time of a mold opening start. It is sectional drawing of the vertical direction which shows the state after mold opening. FIGS. 4A to 4D are cross-sectional views showing an injection-compression molding process using a conventional injection mold.

DESCRIPTION OF SYMBOLS 1 Fixed side core 10 Shaping surface 2 Fixed side plate 20b Parting surface 3 Receiving plate 4 Movable side moving core 40a Shaping surface 5 Movable side plate 50 Movable side fixed core 50a Parting surface 7 Guide post unit C Molding space H 1 Next mold clamping mechanism MM Movable side mold part MS Fixed side mold part

Claims (2)

It has a fixed side mold part and a movable side mold part, and after the mold space is cut off from the outside and the primary mold is clamped before the mold clamping of both mold parts is completed, the mold space is filled with resin and filled. An injection mold that completes mold clamping while compressing resin to obtain a molded product,
The fixed side mold part is
A fixed side core whose surface facing the movable side mold part is a shaping surface corresponding to one side of the molded product;
A fixed-side plate that is disposed around the fixed-side core, and whose surface facing the movable-side mold part is a parting surface that surrounds the shaping surface;
The fixed side core and the fixed side plate are recessed with the shaping surface of the fixed side core flush with the parting surface of the fixed side plate or on the fixed side mold part side from the parting surface. Fixed to each other so as to be arranged in position,
The movable side mold part is
A backing plate,
A movable side moving core that is held on the fixed side mold part side of the backing plate and whose surface facing the shaping surface of the fixed side core is a shaping surface corresponding to the opposite surface of the molded product;
A movable-side fixed core disposed around the movable-side moving core on the fixed-side mold part side of the backing plate, and the movable-side fixed core with respect to the movable-side moving core and the backing plate, and the opposite of the clamping direction A plate member that is held so as to be relatively movable in the mold opening direction, and a surface that faces the parting surface of the fixed-side mold part is a movable parting surface that is pressed against the parting surface of the fixed-side plate. Side plates,
Arranged between the movable side plate and the receiving plate, urging the movable side plate in the direction of mold clamping, and when clamping the mold, before the completion of mold clamping of both mold parts, The primary mold is clamped to the primary mold by blocking the molding space formed between the shaping surfaces facing each other of the stationary core and the movable movable core by being pressed against the parting surface of the stationary plate. A fastening mechanism;
The movable side moving core is always recessed from the parting surface of the movable side plate to the movable side mold part side regardless of the relative movement position of the movable side plate. It is held on the backing plate so that it is placed at the position,
In order to guide the movable side moving core and the movable side plate to the movable side mold portion so as to be relatively movable in the mold clamping direction while positioning the movable side plate and the movable side plate in a direction orthogonal to the mold clamping direction
A movable side fixed core or plate member constituting the movable side plate, a cylindrical guide bush fixed to one side of the movable side moving core, fixed to the other side, and penetrated through a hollow portion of the guide bush. The rolling element includes a rod-shaped guide post, a rolling element interposed between the guide bush and the guide post, and a retainer that rotatably holds the rolling element between the guide bush and the guide post. To provide a guide post unit in which the guide bush moves linearly along the guide post , and
A guide hole penetrating in the mold clamping direction is provided on one side of the movable side fixed core or plate member and the movable side moving core constituting the movable side plate, and a guide post is inserted into the guide bush on the other side. In addition to assembling the guide post unit, prior to mold matching of the movable side plate and the movable side moving core, the guide hole is inserted into the guide hole, and these members are positioned in a direction orthogonal to the mold clamping direction. An injection mold comprising a guide pin for guiding relative movement in a mold clamping direction . The guide bush of the guide post unit is fixed to one side of the movable side fixed core and the movable side movable core, and the guide post is fixed to the other side, and the guide hole is fixed to the movable side fixed core and the movable side movable core. The guide post unit, the guide hole, and the guide pin directly connect the movable side fixed core and the movable side moving core to the mold clamping direction. The injection mold according to claim 1 , wherein the injection mold is guided in a mold clamping direction while being positioned in an orthogonal direction.

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