JP3366714B2 - Injection molding apparatus and injection molding method using the apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding device for plastics and the like, and more particularly to an injection molding device for making holes in a product in an ideal state in a mold during injection molding.

[0002]

2. Description of the Related Art Conventionally, in the hole processing of an injection-molded article, a pin corresponding to a hole is preliminarily set up in a cavity portion of an injection-molding die to be filled with resin, or a pin corresponding to a hole is not provided. After filling the resin with, and solidifying by cooling, the molded product was taken out from the mold, and the hole was machined in the process after the injection molding. However, in the former case, when the resin flows around the pins for holes provided in the mold, the linear marks, that is, the weld line, that allows the resin to split once by the pins and then join again. Occurs.
This weld line is not preferable because it is a defect in appearance, and in the case of a molded product that requires strength, the weld line portion becomes weaker in strength, so it is necessary to take measures such as increasing the thickness of the molded product. It was

The pin for the hole in the mold opening / closing direction may be simply fixed. However, in order to process a hole in a direction different from the mold opening / closing direction, for example, in the lateral direction, the pin is molded before opening the mold. Need to be pulled out from. For this reason, a mold part called a slide core that is slidable in the lateral direction is provided inside the mold when the mold is opened and closed, and the slide core is pulled out by a diagonal pin or a rack and pinion. There is.
However, in addition to the problem of a weld line, there is a problem that the slide core and the like are compact but have a complicated structure, and galling or the like occurs at the time of pulling out.

On the other hand, in the latter, after the molded product is taken out from the mold after injection molding and cooling and solidification, the hole is machined by a mechanical process or the like in a later step, so that the weld line due to the pin or the like is not generated. However, since the number of steps is increased, there are problems that the cost is high and the rate of occurrence of defects such as scratches in the machining process and the conveying process is increased.

Therefore, the Japanese Patent Application Laid-Open No.
As disclosed in Japanese Patent No. 244520, as a method of molding a molded product having a hole without a weld line during injection molding, a fixed-side mold and a movable-side mold for molding a product having a hole are provided with respective molds. A hole corresponding to the hole position of the product part of the mold is provided, and a first punch member for product hole machining is provided in the corresponding hole, and a plastic injection-filled between the two dies for the first punch member. The second punch member is slidably inserted through each of the first punch member and the second punch member so as to be slidable through the first punch member and / or the second punch member after injection filling, during the pressure holding process, or during cooling after the pressure holding is completed. Minute vibration is applied to the punch member, and the plastic in the vicinity of the punch member is softened by this vibration energy, and when the plastic is sufficiently softened, the first or / and the second
The punch member of (1) is forcibly displaced to form a hole in the product (hereinafter referred to as the in-mold vibration finishing punching method).

According to this in-mold vibration finishing punching method,
Weld lines were not generated, and the precision and surface roughness of the machined holes were improved, providing a product that is as good as a machined product. However, in the in-mold vibrating finish removal method, each punch member for forming holes must be centered in both the fixed mold and movable mold for molding, and they must be slidably mounted. Therefore, there are problems that the precision of the mold needs to be increased, the number of parts increases, the thickness of the mold increases, and a device for processing scraps is required when forming a lateral hole. Further, the control is complicated such that one punch member must be controlled so as to be driven / synchronizable with the other punch member via the injection-filled plastic.

[0007]

[Patent Document 1] Japanese Patent Laid-Open No. 4-3
In Japanese Patent Publication No. 69517, a pressure pin corresponding to the above-mentioned punch member is provided only on the movable mold side, and is pressed into a cavity chamber while giving vibration or the like during injection molding to perform hole processing. ing. However, in this product, there is no punch member that moves to face the pressure pin described in the above-mentioned in-mold vibration finishing punching method, so that resin is accumulated between the tip of the pressure pin and the fixed mold, or thin. The resin layer, so-called skin layer remains, and there is a problem that the resin reservoir and the skin layer have to be reprocessed in a later step, the surface of the processed portion becomes rough, and lateral holes cannot be processed.
As a countermeasure against this, at the hole drilling position, a hole to be fitted with the pressure pin is provided on the fixed mold side, and the pressure pin is pushed with vibration or no vibration so as to remove the resin accumulation or the skin layer in the mold during the injection molding process. It is conceivable to separate the resin reservoir or the skin layer from the product at the fitting portion. However, since the resin remains on the fixed mold side, a new problem arises in that the structure is complicated, such as providing a discharge pin for discharging the resin pool or the like in the fixed mold.

The present invention has been made in view of the above problems of the prior art. When performing hole processing on a molded product during the injection molding process, one punch member is used for one hole. Performs hole drilling and horizontal hole drilling, eliminates resin residue such as skin layer in the hole of the molded product, makes it easy to discharge, does not require post-processing, has good accuracy, and has good surface roughness It is an object of the present invention to provide an injection molding device that obtains various molding holes.

[0009]

To this end, the present invention provides an injection molding apparatus as claimed in the claims,
The above-mentioned problems of the prior art have been solved.

[0010]

Before the injection, the punch member and the discharge pin are arranged such that their end surfaces are substantially aligned with the space forming a part of the cavity. After the injection and filling, or during the pressure holding process, or during the cooling after the pressure holding is completed, the punch member corresponding to the forming hole provided on the movable mold side is thrust into the cavity while being vibrated. When the fitting concave portion or the fitting convex portion provided on the fixed mold side and the outer or inner edge portion of the sleeve-shaped punch member are fitted, the resin is cut at the fitting edge portion. Further, the punch member is crushed or stopped, but the crushed resin is retained in the resin reservoir formed by the discharge pin, the punch member, the fitting edge, and the fitting projection or the fitting recess. To be done.
When the mold is opened after injection cooling, the solidified resin in the resin reservoir is attached to the punch member side and released from the fixed mold side.

Further, as the movable mold is opened, a discharge pin, which penetrates the punch member and has one end fixed to the ejector plate, is projected and the solidified resin in the resin reservoir attached to the punch member side is removed. Is discharged. At the same time, the injection molded product or the like attached to the movable mold side is discharged from the movable mold by the product discharge pin and the sprue discharge pin.

In the processing of a lateral hole or an oblique hole, the punch member and the discharge pin are arranged such that their end faces are substantially aligned with the space forming a part of the cavity before injection. After the injection filling, during the pressure holding process, or during the cooling after the pressure holding is completed, the punch member is rushed into the cavity while being given a minute vibration. After the completion of injection molding, and when the fitting concave portion or the fitting convex portion provided on the fixed mold side fits the outer or inner edge portion of the sleeve-shaped punch member, the resin is cut at the fitting edge portion. The discharge molding resin surrounded by the fitting concave portion or the fitting convex portion, the punch member, and the discharge pin is attached to the punch member side, and the punch member, the discharge pin, and the discharge molding resin are left as they are without any vibration or the like, and gold is applied. After the mold is drawn into the mold, the movable and fixed molds are opened, and the discharge pin is projected to discharge the discharge molding resin.

If the discharge pin is movable independently in the punch member, after injection filling or during the pressure holding process,
Or, during cooling after the holding pressure is completed, the punch pin corresponding to the forming hole provided on the movable mold side is retracted as it is thrust into the cavity while being vibrated. It is possible to reduce the volume decrease in the mold and the pressure increase in the mold due to the punch member rushing.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will now be described with reference to the drawings. FIG. FIG. 4 is an explanatory view showing a hole processing portion of the present invention. In each figure, FIG. 2 shows a state before drilling, FIG. 3 shows a state after drilling, and FIG. 4 shows a discharge state of unnecessary resin formed in the resin reservoir. The number of processed holes is one.

In FIG. 1, the mold includes a fixed mold 2 and a movable mold 1, and a runner portion 3, a gate portion 4 and a product portion 5 are formed on the contact surfaces of both molds 2 and 1. A cavity or core 6 is formed, and a punch member 7 constituting a product hole processing portion that can be inserted into the cavity or core 6 is slidably incorporated in the movable mold 1. In addition, a fitting concave portion 17 corresponding to the hole position of the product portion of the mold is provided in the fixed mold 2. 8 is a sprue, and the runner part 3 connects the gate part 4 and the sprue 8. Punching member 7
With the hydraulic servo cylinder 9, a minute vibration or a gentle reciprocating motion can be selected by program control. A fast response proportional valve may be used in place of the servo valve 12 which gives minute vibration or gentle reciprocating motion. Product discharge pin, sprue discharge pin and discharge pin, 1
One end of each of 0, 11, and 18 is fixed to the ejector plate 15 so as to penetrate the movable mold 1. The discharge pin 18 includes the servo cylinder rod 14 and the punch member 7.
Penetrate through. As shown in FIGS. 2 and 3, by moving the punch member, the outer shape tip portion 7b of the punch member and the fitting edge portion 17a of the fitting concave portion 17 are fitted in the fitting portion 20, Punch member 7, fitting portion 20, fitting recess 17
A resin reservoir 19 surrounded by the discharge pin 18 is formed.

The operation of this embodiment will now be described. In FIG. 1, the inflowing melted resin 13 is introduced into the cavity or core 6 from the injection molding cylinder (not shown) through the sprue 8, runner portion 3 and gate portion 4. Then, the product part 5 is formed. At this time, since the punch member is located as shown in FIG. 2 and does not obstruct the inflow path of the inflowing melted resin 13, no weld line is generated. Next, after the resin 13 is injected into the cavity or the core 6, or during the pressure-holding process or during the cooling after the pressure-holding is completed, the punch member 7 is compressed while applying no vibration or vibration to the left and right as viewed in FIG. Sushi punch member 7
Is forced to move to the right, the resin 13 will
As shown in FIG. 3, the punch member 7 is dispersed and compressed in the resin reservoir 19 in the cavity or core 6 as shown in FIG.
The hole 21 to which the shape of the outer side portion 7a is transferred is processed.
The punch member 7 fits with the fitting edge portion 17a while vibrating,
Since the product portion 5 and the resin reservoir portion 19 are separated from each other, this separation surface is accurately separated, and if the punch member is stopped at the fitting portion 20 and brought into contact therewith, the surface roughness is also improved.

Then, after the cooling of the inflowing melted resin 13 is completed, the movable mold 1 is retracted and the mold is opened as in the conventional injection molding, and the runner portion 3 and the product portion 5 are sprue discharge pins 11 and product discharge pins. Discharged by 10. On the other hand, when the die is opened, the punch member 7 is set at a fixed position with respect to the movable die 1, and the inner side 7c of the punch member and the discharge pin 18 hold the molding member filled in the resin reservoir 19. On the other hand, the fitting recess 17 side has a hemispherical shape, and the molding member is more easily released from the fixed mold 2 side than the punch member side.
The molding member adheres to the movable mold 1 side and is taken out. Figure 4
As shown in Fig. 5, the discharge pin 18 is pushed out at the same time as the runner portion 3 and the like are discharged by the sprue product discharge pin 11 and the like when the movable mold 1 is retracted (opened). Is discharged and the molding process is completed. Before the next mold clamping, the punch member 7 is returned to its original position so as to be ready for the next molding.

Since the resin softening and hole drilling steps are completed within just a few seconds, the steps can be completed by the time the cooling of the product portion is completed, which does not hinder the productivity as compared with conventional molding. Further, since there is no weld line since holes are formed after injection filling, and since the products are separated while applying vibration, a product with a clean cut surface with high precision can be obtained. Furthermore, the molded product of the resin reservoir can be efficiently discharged.

FIGS. 5 to 7 are explanatory views showing a second embodiment of the present invention. In the following description, parts having similar configurations will be assigned the same reference numerals and part of the description will be omitted. In the first embodiment, when the hole diameter is smaller than the hole depth, the discharge pin 18 may be too small and may be insufficient in strength. Therefore, in the second embodiment, the convex fitting convex portion 16 is provided on the fixed mold side, and the fitting convex portion 16 is provided.
With the inner tip portion 7d of the sleeve-shaped punch member 7, the molded product of the resin reservoir 19a is separated from the product. Figure 6
6 is an explanatory view of the periphery of the punch member 7 during injection filling, and the punch member 7 and the discharge pin 18 are located slightly left of the finished size position 22 of the product. A fitting convex portion 16 forming a forming hole is provided in the fixed mold 2, and the fitting edge portion 16a of the fitting convex portion 16 and the punch member inner end portion 7d are fitted with each other as the punch member 7 moves. Mating part 2
It is designed to form 0. As shown in FIG. 7, by moving the punch member 7 to the right, the punch member inner tip portion 7 is moved.
d and the fitting edge portion 16a are fitted to each other, and a resin reservoir 19a surrounded by the punch member, the fitting portion 20, the fitting convex portion tip 16b and the discharge pin 18 is formed. There is. Other configurations are similar to those of the first embodiment described above as shown in FIG.

Next, the operation of the second embodiment will be described.
In FIG. 5, the inflowing melted resin 13 is supplied from the injection molding cylinder (not shown) to the sprue 8, the runner portion 3 and the gate portion 4.
Is introduced into the cavity or core 6 through the
Is formed. At this time, the punch member 7 is in the position as shown in FIGS. 5 and 6, and the inflow melting resin 13 is blocked by the fitting convex portion 16 of the fixed mold 2 in the inflow path, but the movable mold 1
Since the resin is continuously supplied through the space portion 23 formed by the punch member and the fitting convex portion of the fixed mold which are provided slightly backward, no weld line is generated. Next, after the resin 13 is injected into the cavity or the core 6, or during the pressure-holding process, or during the cooling after the pressure-holding is completed, the punch member is vibrated or vibrated left and right as viewed in FIGS. When 7 is forcibly moved to the right, the resin 13 is dispersed and compressed in the product portion 5, the cavity or core 6, and the resin reservoir portion 19a, and the product portion 5 has a fitting protrusion as shown in FIG. 16
The hole 21a having the transferred outer shape is processed. Also,
The punch member tip end surface 7e contacts the product portion 5 and is transferred. Since the punch member 7 fits with the fitting edge portion 16a while vibrating, this separation surface is accurately separated, and the surface roughness is also improved by stopping the punch member at the fitting portion 20 and contacting it.

Then, after the cooling of the influent resin 13 is completed,
As in the first embodiment described above, the mold is opened, and the runner portion 3 and the product portion 5 have the sprue discharge pin 11 and the product discharge pin 10 respectively.
Discharged by. On the other hand, when the die is opened, the punch member 7 is set at a fixed position with respect to the movable die 1, and the punch member inside 7
While the molded member filled in the resin reservoir 19a can be held by the c and the discharge pin 18, the tip end face 16b of the fitting convex portion is only in contact with the resin reservoir portion. Therefore, since the molding member is more easily released from the fixed mold side than the punch member side, the molding member is attached to the movable mold side and taken out. The subsequent operation is similar to that of the first embodiment.

FIG. 8 is an explanatory view showing a third embodiment of the present invention. In the first and second embodiments, one end of the discharge pin is fixed to the ejector plate, and the product discharge pin, the sprue discharge pin, and the discharge pin are automatically and simultaneously projected as the movable mold is opened. However, in the third embodiment, the discharge pin can be operated separately from other product discharge pins and the like. In FIG. 8, the discharge pin 31 is fixed or integrally provided with a rod 33 slidable in a hydraulic cylinder 32, and the hydraulic cylinder is fixed to the ejector plate 15. A control valve 36 is provided between the hydraulic cylinder and the hydraulic source so that the oil inlet and outlet of the hydraulic cylinder 32 are connected to the hydraulic source 34, and the other oil inlet and outlet of the hydraulic cylinder and the oil tank 35 are alternately communicated. . Control valve 36
A pressure control valve 38 capable of maintaining a constant supply pressure to the hydraulic cylinder is provided between the oil inlet / outlet 37 on the ejector plate side (hereinafter referred to as the outlet side) of the hydraulic cylinder 32.

The pressure control valve 38 has its pressure set value adjusted manually or electrically, and when the pressure at the outlet 38b of the pressure control valve is lower than the set value, the pressure oil from the hydraulic source is discharged to the outlet side of the hydraulic cylinder 32. Supply to the oil inlet / outlet 37, and the outlet 38b
When the pressure is higher than the set pressure, the pressure oil at the outlet oil inlet / outlet 37 is discharged to the oil tank 35 to keep the supply pressure to the outlet side of the hydraulic cylinder constant. When the control valve 36 is controlled to the position of 36b, the pressure oil is supplied to the hydraulic cylinder outlet 37 through the pressure control valve 38 and the discharge pin 3 is discharged.
1 is moved to the right as viewed in the figure, and is made to be substantially flush with the tip of the punch member 7 at the stroke end. On the contrary, when the control valve is set to the state of 36a, the pressure oil is supplied to the fixed mold side oil inlet / outlet 32a of the hydraulic cylinder 32, and the discharge pin 31 moves leftward in the figure. Other configurations are similar to those of the first or second embodiment described above as shown in FIG.

Next, the operation of the third embodiment will be described.
In FIG. 8, the inflowing melted resin 13 is supplied from the injection molding cylinder (not shown) to the sprue 8, the runner portion 3 and the gate portion 4.
And is introduced into the cavity or core 6 through the through hole to form the product portion 5 in which no weld line is generated as described above. At this time, the control valve 36 is supplied with pressure oil to the outlet side 37 of the hydraulic cylinder and the discharge pin 31 reaches the stroke end. At this time, the set pressure of the pressure control valve 38 is higher than the injection pressure. (In pressure conversion),
The discharge pin 31 is designed not to retract.

Next, after the resin 13 is injected into the cavity or the core 6, or during the pressure-holding process, or during the cooling after the pressure-holding is completed, the punch member is vibrated or vibrated left and right as viewed in FIG. When 7 is forcibly moved to the right, the resin 13 is dispersed and compressed in the product portion 5, the cavity or the core 6, and the resin reservoir portion, and the pressure of the resin in the mold gradually increases.
There is no problem if the resin compression ratio in the mold is small,
If the compression ratio is large, the pressure increase of the resin in the mold becomes too large, and the punch member 7 cannot penetrate. However, when the resin pressure in the mold becomes equal to or higher than the output of the discharge pin 31 according to the set pressure of the pressure control valve 38, the discharge pin is pushed to the left to increase the internal volume of the mold, Since the pressure is not made higher than the set pressure of the pressure control valve, the punch member 7 can perform a predetermined hole machining without receiving excessive resistance.

Next, after the cooling of the influent resin 13 is completed,
After returning the control valve 36 to the neutral position and fixing the hydraulic cylinder,
Similar to the other embodiments, the movable mold 1 is retracted to open the mold, the runner portion 3, the product portion 5, and the molding member of the resin pool are discharged, and the molding process is completed. Before the next mold clamping, the punch member 7 and the discharge pin 31 are returned to their original positions so as to be prepared for the next molding. The stroke of the hydraulic cylinder 32 is appropriately set according to the amount of compression generated by the thrust of the punch member 7. Further, when the hydraulic cylinder 32 is attached to the movable mold 1, the ejection pin 31 cannot be protruded by interlocking with the ejector plate 15, so the control valve 3
6 is switched again to move the hydraulic cylinder 32 to the right, and the molding member in the resin pool is discharged. Further, the mold release time after mold opening can be shifted from the product and sprue discharge time.

9 to 13 and 14 to 18 are explanatory views showing the fourth and fifth embodiments of the present invention. In the first and third embodiments, the hole axis of the machined hole is aligned with the opening and closing direction of the mold, but in the fourth and fifth embodiments, the axis of the machining hole is perpendicular to the mold opening and closing direction. It is provided so that a lateral hole can be drilled. FIG. 9 shows both the fourth and fifth embodiments.
And as shown in FIG. 14, the cavity 6 of the movable mold 1a.
The a forming portion is convex, the cavity 6b of the fixed mold 2a is concave, and the movable mold and the fixed mold form a box-shaped cavity 6c.
Is formed, and a punch member or the like attached to the side surface of the fixed mold is used to form a hole in the side surface of the box-shaped cavity.

A servo cylinder 9 is attached to the side surface 2b of the fixed mold 2a by a mounting member 39 so that the punch member 7 coupled to the servo cylinder rod 14 similar to the third embodiment can be inserted. 12 is attached. In addition, the punch member 7 and the discharge pin 3
1 can be drawn into the fixed mold 2a from the cavity 6b. Further, at the rear portion of the servo cylinder, a hydraulic cylinder is attached, which is fixed to or integrally provided with a rod 33 which penetrates the punch member 7 and the servo cylinder rod 14 and has a discharge pin 31 slidable in the hydraulic cylinder 32. ing. The hydraulic cylinder 32 can be moved in and out by a hydraulic control circuit (not shown), such as that shown in FIG. Further, the punch member 7
To the movable mold 1a side with the cavity 6c interposed therebetween,
In FIG. 9, the fitting concave portion 17 is provided, and in FIG. 14, the fitting convex portion 16c is provided. Other configurations are similar to those of the above-described embodiments and the like.

Next, the operation of the fourth embodiment, which is an example of the lateral hole machining of the first embodiment, will be described. In FIG. 9, the inflowing melted resin 13 is introduced into the cavity or core 6c from the injection molding cylinder (not shown) through the sprue 8, the runner portion 3 and the gate portion 4 to form the product portion 5a. At this time, the punch member is in the position as shown in FIG. Further, as shown in FIG. 9, the punch member 7 is compressed vertically while applying no vibration or vibration to forcibly move the punch member 7 upward to form the hole 21 as shown in FIG.
And the resin reservoir 19 are separated. The process up to this point is the same as in the first embodiment.

Next, after the cooling of the inflowing dissolved resin 13 is completed,
Before the movable mold 1a is retracted, the resin pool 19 is drawn into the fixed mold 2a while being held by the punch member 7 and the discharge pin 31 as shown in FIG. And do not interfere. When the punch member is vibrated at the time of pulling in, the molded product and the resin pool portion are re-welded by vibration or vibration friction energy, so the punch member is pulled in without giving vibration. Further, since the surface of the molded product hole 21 is smoothed by the vibration of the punch member when the punch member is pushed in, the punch member and the resin reservoir can be pulled in without resistance and no galling or the like occurs. Then, the mold is opened and the product portion 5a is pulled out to the movable mold as shown in FIG. 13, and then the discharge pin 31 is ejected to discharge the resin reservoir 19. Furthermore, the product 5a is a sprue discharge pin 1.
1. The product is discharged by the product discharge pin 10, and the molding process is completed. Before the next mold clamping, the punch member 7 is returned to its original position so as to be ready for the next molding.

The fifth embodiment shown in FIGS. 14 to 18 is the same as the fourth embodiment, which is the embodiment of the lateral drilling of the first embodiment described above, and the lateral drilling of the second embodiment is performed. Here is an example. In addition, in the fifth embodiment, the case where the hole is not a straight hole but a stepped hole will be described together. To describe the operation of the fifth embodiment, in FIG. 15, the fitting convex portion 16c is provided in the movable mold with the counter boring thickness being shorter than the cavity thickness. In FIG. 14, the inflowing melted resin 13 is the cavity or core 6a as described above.
Introduced therein, the product part 5a is formed. At this time, the punch member 7 is in the position shown in FIG.

Next, the resin 13 is added to the cavity or core 6c.
When the punch member 7 is forcibly moved upward while applying no vibration or vibration in the vertical direction as viewed in FIG. 14 after injection and filling, during the pressure holding process, or during cooling after the pressure holding is completed, the resin 13 is dispersed and compressed in the product portion 5a, the cavity or core 6c, and the resin reservoir portion 19a, respectively, and the product portion 5a includes a punch member tip end surface, a tip outer periphery, and a fitting protrusion 16c as shown in FIGS. The stepped hole 21b to which the outer shape formed in step 1 is transferred is formed. Since the punch member 7 fits with the fitting edge portion 16a while vibrating, this separation surface is accurately separated, and the surface roughness is also improved by stopping the punch member at the fitting portion 20 and contacting it.

Next, after the cooling of the influent resin 13 is completed,
Before retracting the movable mold 1a, as shown in FIG. 17, the resin reservoir 19a is drawn into the fixed mold 2a while being held by the punch member 7 and the discharge pin 31, and the molded product and the resin are removed when the molded product is removed from the mold. Avoid interference with the pool. Next, the mold is opened, and as shown in FIG. 18, the product portion 5a is pulled out to the movable mold, and then the discharge pin 31 is ejected to discharge the resin reservoir 19a. The subsequent operation is similar to that of the fourth embodiment.

When a plurality of holes are to be machined, a plurality of servo cylinders, punch members and discharge pins may be provided, or a plurality of punch members may be provided in one servo cylinder and discharge pins that penetrate each punch member. It is needless to say that various combinations and configurations are possible, such as providing a spring, combining a spring and a hydraulic cylinder, and mechanically providing a discharge pin that penetrates the punch member. Further, it goes without saying that the punch member and the like can have any shape such as a star shape as well as a circular hole. Further, in the fifth embodiment, the stepped hole is formed by the shorter fitting convex portion and the punch member, but if the punch member or the fitting convex portion is stepped or tapered, a stepped hole or a tapered hole is formed. Very easy to do. In the embodiments, the mold opening / closing direction and the right angle direction have been described, but it goes without saying that the invention can also be applied to processing in an oblique direction.

[0035]

Since the present invention is configured as described above, it has the following effects.

When a hole is formed in a molded product during the injection molding process, one hole can be formed by one punch member. Therefore, it is possible to perform the conventional in-mold vibration finishing punching method using two punch members. Such a complicated structure and control are not required, the thickness of the die is thin, and the centering of each punch is not required, resulting in low cost.

Further, not only the mold opening / closing direction, but also the lateral or diagonal hole processing can be performed during the injection molding process.

Further, since the inflow path of the inflowing dissolved resin is not obstructed during the injection filling, a product excellent in appearance without flow traces, that is, weld lines, which cannot be obtained by the conventional fixed pin system, is obtained. You can get it.

In particular, the resin residue such as the skin layer generated in the hole of the molded product is separated into the product and the resin reservoir during the injection molding process, and the resin reservoir like the product discharge pin of the product is opened when the mold is opened. Since the molded product of (1) can be discharged, the resin residue such as the skin layer is removed from the product, and it is easy to discharge, and the post-process is unnecessary.

Further, since the fitting concave portion or the fitting convex portion which can be fitted with the punch member is provided on the fixed mold side, the punch member is provided after injection filling or during the pressure holding process or after the pressure holding is completed. It becomes possible to perform hole drilling by vibrating or reciprocally vibrating to soften the resin in the vicinity of the punch member and the fitting edge portion by the vibration energy. Therefore, if the punch member is brought into contact and slide at the fitting edge portion during the injection molding process,
It became possible to obtain a molding hole with high accuracy and good surface roughness.

Further, since the discharge pins can be independently moved, the punch member can be more surely pushed into the mold, and the punch member has a small push force and a uniform resin density.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an injection molding apparatus used in a first embodiment of the present invention.

FIG. 2 is an explanatory diagram around a punch member of the injection molding apparatus used in the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of the periphery of the punch member when the displacement of the punch member of the injection molding apparatus used in the first embodiment of the present invention is completed.

FIG. 4 is an explanatory diagram of the periphery of the punch member when the punch member is retracted in the injection molding apparatus used in the first embodiment of the present invention.

FIG. 5 is a sectional view of an essential part showing an injection molding apparatus used in a second embodiment of the present invention.

FIG. 6 is an explanatory diagram around a punch member of an injection molding apparatus used in a second embodiment of the present invention.

FIG. 7 is an explanatory diagram around the punch member when the displacement of the punch member of the injection molding apparatus used in the second embodiment of the present invention is completed.

FIG. 8 is a cross-sectional view of an essential part showing an injection molding device used in a third embodiment of the present invention.

FIG. 9 is a cross-sectional view of an essential part showing an injection molding device used in a fourth embodiment of the present invention.

FIG. 10 is an explanatory diagram around a punch member of an injection molding device used in a fourth embodiment of the present invention.

FIG. 11 is an explanatory diagram of the periphery of the punch member when the displacement of the punch member of the injection molding apparatus used in the fourth embodiment of the present invention is completed.

FIG. 12 is an explanatory diagram of the periphery of the punch member when the punch member is retracted in the injection molding device used in the fourth embodiment of the present invention.

FIG. 13 is an explanatory diagram of the periphery of the punch member when the punch member is retracted in the injection molding device used in the fourth embodiment of the present invention.

FIG. 14 is a cross-sectional view of an essential part showing an injection molding device used in a fifth embodiment of the present invention.

FIG. 15 is an explanatory diagram around a punch member of an injection molding device used in a fifth embodiment of the present invention.

FIG. 16 is an explanatory diagram of the periphery of the punch member when the displacement of the punch member of the injection molding apparatus used in the fifth embodiment of the present invention is completed.

FIG. 17 is an explanatory diagram of the periphery of the punch member when the punch member is retracted in the injection molding device used in the fifth embodiment of the present invention.

FIG. 18 is an explanatory diagram of the periphery of the punch member when the punch member is retracted in the injection molding device used in the fifth embodiment of the present invention.

[Explanation of symbols]

1,1a movable mold 2, 2a Fixed mold 6,6c Cavity or core 7 Punch member 7a Punch member outer side 7b Outside edge of punch member 7c Punch member inside 7d Punch member inside tip 7e Punch member tip end face 10 Product discharge pin 11 Sprue discharge pin 13 Resin (inflow dissolution resin) 14, 14a Servo cylinder rod 15 ejector plate 16, 16c Fitting convex part 16a, 17a Mating edge 16b convex end face 17 Fitting recess 18, 31, 31a Discharge pin 19, 19a Resin pool 20 Fitting part 21, 21a hole (processed hole) 21b Stepped hole 23 Space 32 hydraulic cylinder 36 control valve 37 Ejector plate side (outlet side) oil inlet / outlet 38 Pressure control valve

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yukio Nakamura 4-11-4 Nishikawaguchi, Kawaguchi City, Saitama Nissui Kako Co., Ltd. (72) Inori Inori, Yoneoka 4-114 Nishikawaguchi, Kawaguchi City, Saitama Prefecture (56) Reference JP-A-4-369517 (JP, A) JP-A-3-244520 (JP, A) JP-A-3-138121 (JP, A) JP-A-7-178779 (JP, A) JP-A-6-297511 (JP, A) JP-A-7-100878 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 45/56 B29C 45 / 17 B29C 45/26 B29C 45/40

Claims (7)

(57) [Claims] 1. A punch having a punch member provided in a movable mold or a fixed mold so as to be capable of plunging into a cavity, the punch after injection filling, during a pressure holding process, or during cooling after the pressure holding is completed. An injection molding machine that processes a molding member by giving a minute vibration to the member and forcibly displacing and compressing the molding member by vibrating or vibrating the punch member while softening the plastic near the punch by this vibration energy In the punch member, the punch member has a sleeve shape, and the punch member is provided so as to be slidable inside the sleeve-shaped punch member and the punch member so as to face the punch member with a part of the cavity interposed therebetween. An injection molding device, comprising: a fitting concave portion or a fitting convex portion having a fitting edge portion adapted to fit with an inner or outer edge portion of the. 2. The injection molding according to claim 1, wherein the sleeve-shaped punch member and the discharge pin can be ejected and drawn in a direction different from a mold opening / closing direction of the movable mold and the fixed mold. apparatus. 3. The injection molding apparatus according to claim 1, wherein the sleeve-shaped punch member is configured to be capable of protruding into the cavity and retracted into a fixed mold or a movable mold. 4. The punch member is connected to a servo cylinder rod and driven by a servo cylinder, and the discharge pin has one end fixed to an ejector plate and penetrates the movable mold, the servo cylinder rod and the punch member. 2. The method according to claim 1, wherein
Alternatively, the injection molding apparatus according to item 3. 5. The injection molding apparatus according to claim 1, 2, 3, or 4, wherein the discharge pin is movable independently. 6. The injection molding apparatus according to claim 1, 3, 4 or 5, wherein the punch member and the discharge pin have their end surfaces substantially aligned with a space forming a part of the cavity before injection. After the injection and filling, or during the pressure holding process, or during the cooling after the pressure holding is completed, the punch member is rushed into the cavity while giving a minute vibration, and further rushed into the fitting edge portion to be fitted. Vibration at the edge for a short time or stop fitting at the mating edge without vibration, after injection molding is completed,
When the movable and fixed molds are opened, the discharge molding resin surrounded by the fitting concave portion or the fitting convex portion, the punch member and the discharge pin is attached to the punch member side, and the discharge pin is released after or during the mold opening. The injection molding method characterized in that the discharge molding resin is discharged by ejecting. 7. The injection molding apparatus according to claim 2, 4, or 5, wherein, before injection, the punch member and the discharge pin have their end surfaces substantially aligned with a space forming a part of the cavity. After the injection and filling, or during the pressure-holding process, or during the pressure-holding process or during the cooling after the pressure-holding is completed, the punch member is rushed into the cavity while giving a slight vibration, and further rushed into the fitting edge portion to fit the fitting edge. After the injection molding is completed, the discharge molding resin surrounded by the fitting concave portion or the fitting convex portion, the punch member and the discharge pin is punched on the punch member side. After pulling the punch member, the discharge pin and the discharge molding resin into the mold as they are, the movable and fixed molds are opened, and then the discharge pin is ejected to discharge the discharge molding resin. Special to do Injection molding method.