JPH09201828A - Formation of through hole in resin molding and molding die for resin molding used for formation of through hole - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for forming a through hole of desired shape and size and at the same time, manufacturing a resin molding by preventing resin waste produced by the formation of the through hole from remaining unremoved in the resin molding, and a molding die for the resin molding used for the method for forming the through hole. SOLUTION: A soft resin layer 28 positioned in a molding cavity 16 is tightly formed on the cavity face 20 of the molding cavity 16. Next, a sliding core 14 is moved backward from the cavity face 20 in such a state that the soft resin layer 28 is brought into contact with a cavity face constituting area 18 which constitutes part of the cavity face 20. In addition, the outer peripheral edge part 32 of the sliding core welding part 30 of the soft resin layer 28 welded to the cavity face constituting area 18 of the sliding core 14, is stretched into a thin wall part. Further, the sliding core welding part 30 is cut off the soft resin layer 28 by hardening the thin wall part by cooling.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method of forming a through hole of a resin molded product and a mold for molding a resin molded product used therefor, and particularly, to a resin molded product having a through hole of a desired shape and size. In addition, the present invention relates to a technique that can be advantageously formed.

[0002]

2. Description of the Related Art Conventionally, as one type of method for producing a resin molded product, a predetermined pressing force is applied to a softening resin layer positioned in a molding cavity of a mold to form the softening resin layer in the cavity of the molding cavity. A method is known in which the resin is adhered to the surface and then cooled and solidified to obtain a desired resin molded product. For example, a vacuum forming method, a blow forming method, a pressure forming method, or the like, and in these forming methods, suction force or air pressure is applied to the softened resin layer positioned in the molding cavity to form the softened resin layer. After it is brought into close contact with the cavity surface of the molding cavity, it is cooled and solidified, so that resin molded products having various shapes such as a casing and a bottle can be obtained.

By the way, in a resin molded product having such a casing shape or a bottle shape, for the purpose of venting air or the like,
Through holes may be formed, but in the molding method of resin molded products using the vacuum molding method, blow molding method, pressure molding method, etc. as described above, the softened resin layer is brought into close contact with the cavity surface of the molding cavity. At this time, since the entire cavity surface is completely covered with the softening resin layer, when a normal mold is used, the resin molded product is molded at the same time as the resin molded product is molded. The through hole could not be formed.

Therefore, in the resin molded product obtained by the vacuum forming method, blow molding method, pressure forming method, etc., generally, after the forming, a drilling process using a cutting tool such as a hole saw or a router is performed. Due to this, a predetermined through hole is formed.

However, when the resin molded product is punched using such a cutting tool, post-treatment of the cutting surface must be performed, and the resin molded product is a hollow molded product such as a bottle. However, it becomes difficult to remove the chips that have entered the molded product, and above all, since such a drilling process is a post-process after the molding of the resin molded product, it is difficult to manufacture the resin molded product. In addition to the required steps and devices, not only special steps and devices for forming the through holes are required, but also the positions of the through holes are likely to vary among individual resin molded products. There was a big problem.

In order to solve these problems, various proposals have been made in the past.
Japanese Patent No. 125058 discloses a hollow molding die in which a drilling member having a sharp tip is provided so as to project and move into a molding cavity. A method for forming a hole in a hollow molded article has been clarified in which, when air is blown in, the punching member is caused to move so as to form a hole in the expanded molding material.

According to such a method, a resin molded product having a hollow shape can be obtained, and at the same time, a predetermined through hole can be formed in the hollow molded product, thereby forming a through hole. Although the processing can be advantageously omitted, the through-hole forming step can be efficiently performed, and the through-hole can be formed with high positional accuracy with respect to the hollow molded article. Since it is formed by piercing a drill member on the wall surface of an article, when the drill member is pierced, the periphery of the through hole is pushed inward and deformed, or in some cases, the formation of the through hole. There was a risk that the resin waste generated by this would get inside the hollow molded product.

Further, Japanese Utility Model Publication No. 4-79625 discloses that
The blow mold is provided with a hole-piercing pin that is inserted into the mold cavity from the outside of the mold so as to be movable back and forth in the axial direction and rotatable about the axis. The pin insertion portion of the blow molding die to be inserted is provided with a nest that constitutes a part of the cavity surface of the molding cavity and is elastically held outside the molding die, and further the tip end portion of the hole forming pin. And a hole forming device for blow-molded articles, which is configured such that a divided portion pivotally attached to the pin is provided and the divided portion can be erected in a direction perpendicular to the axis of the pin by an operation from outside the molding die. It is disclosed.

With such a device, after the pin for punching is pierced to form the through hole in the resin molded product, the pin is rotated around its axis in a state where the divided portion is erected, By moving backward from the molding cavity, it is possible to prevent the inward deformation around the through hole and the intrusion of resin scraps into the molded product. On the other hand, it has a very complicated structure in which a hole forming pin or a nest having a divided structure is attached, and when the size of the through hole formed in the resin molded product is increased, In order to make the part pushed into the molded product as small as possible,
It is necessary to keep the size of the pin itself and to enlarge only the divided parts.If the through hole has a complicated shape, it is necessary to increase the number of divided parts or make the shape complicated. In any case, the structure of the pin for punching, and by extension, the structure of the blow molding die itself as a blow molding hole processing device becomes more complicated, and the manufacturing cost of the mold also rises accordingly. Is inevitable.

[0010]

The present invention has been made in view of the above circumstances, and the problem to be solved is to mold a resin molded product by die molding. At this time, a through hole having a desired shape and size can be formed in the resin molded product to be molded without complicating the structure of the die used, and is caused by the formation of the through hole. It is an object of the present invention to provide a through-hole forming method for a resin molded product, which can advantageously prevent resin waste from remaining inside the resin molded product. Further, in the present invention, it is also an object to provide a metal mold for molding a resin molded product that can be advantageously used in forming a through hole in a resin molded product by such a method. Is.

[0011]

In the present invention, in order to solve the above problems, a part of the cavity surface of a molding cavity having a shape corresponding to a resin molded product to be molded is formed. A mold for molding a resin molded product including a slide core that is configured to be capable of moving backward from the cavity surface is used, and after the softening resin layer is positioned in the molding cavity of the mold, the softening resin layer By pressing the softening resin layer against the cavity surface of the molding cavity, the softening resin layer is brought into close contact with the cavity surface of the molding cavity, and then, the cavity surface forming portion of the slide core. With the softened resin layer adhered to the slide core, the slide core is moved backward so that the slide core is closely adhered to the cavity surface forming site. The outer peripheral edge portion of the slide core contact portion of the softened resin layer is stretched to be thinned, and further cooled and solidified to cut and form the slide core contact portion from the softened resin layer at the thinned portion. A method of forming a through hole of a resin molded product, wherein a through hole having a shape corresponding to the slide core contact portion is formed in the resin molded product is characterized.

In short, in the method of forming a through hole of a resin molded product according to the present invention, the mold for molding the resin molded product is:
A mold is used in which a slide core that constitutes a part of a cavity surface of a molding cavity is assembled so as to be able to move backward from the cavity surface. A pin for punching having a split portion that is erected by an external operation is used. However, a mold having an extremely simple structure is used as compared with a conventional method that uses a mold that is arranged so as to be able to move back and forth within the molding cavity and to be rotatable around the axis of the pin. Of. Further, in the method of the present invention, a softening resin layer is brought into close contact with the cavity surface of the molding cavity in such a mold to mold a resin molded article, while the softening resin is applied to the cavity surface forming portion of the slide core. In the state where the layers are brought into close contact with each other, the slide core is moved backward from the cavity surface, and the outer peripheral edge portion of the slide core close contact portion of the softened resin layer is stretched to be thinned, and then the thinned portion is cooled and solidified. By shrinking, the thinned portion is contracted and cut from the softened resin layer, and a shape corresponding to the slide core adhesion portion, in other words, a cavity of the slide core, is formed with respect to the resin molded product molded by the softening resin layer. Since the through hole having the shape corresponding to the surface constituting portion is formed, the shape and the large size of the cavity surface constituting portion of the slide core are simply formed. It is just changing, it is possible to change the shape and size of the slide core contact portion in the softened resin layer, thereby than is the shape and size of the through hole can be easily changed to be formed.

In addition, in the method of the present invention, as described above, by moving the slide core backward from the cavity surface, the slide core of the softened resin layer closely adhered to the cavity surface constituting portion of the slide core is adhered. Since a portion is cut from the softened resin layer and a through hole is formed in a resin molded product molded with the softened resin layer, a resin generated when the through hole is formed It is possible to effectively prevent the slide core contact portion as scraps from entering the inside of the softened resin layer and thus the resin molded product.

Therefore, according to the method for forming a through hole of a resin molded product according to the present invention, when molding a resin molded product by die molding, a mold having a relatively simple structure is used to form a resin molded product. Through holes can be formed, and the shape and size of such through holes can be arbitrarily and easily changed without complicating the structure of such a mold. It can be advantageously prevented that the resin waste generated by the formation of the resin remains inside the resin molded product, whereby a through hole forming mechanism is added to the die used and a through hole formed is formed. It is possible to suppress the rise in mold manufacturing cost due to the change of mold structure due to the change of shape and size as much as possible, and advantageously omit the troublesome work of removing resin scraps from the inside of the resin molded product. Can be done As, in comparison with the conventional, and the improvement of the processing cost and working efficiency at the time of forming a through hole in a resin molded article, all of which as it can be achieved effectively.

According to one of the preferred embodiments of the method for forming a through hole of a resin molded product according to the present invention, a resin molded product having the through hole is molded into a mold for molding the resin molded product. After taking out from the cavity, by moving the slide core forward toward the cavity surface forming position of the molding cavity, the slide core contact portion cut off from the softening resin layer is removed from the slide core, As a result, the slide core contact portion, which is resin waste generated when the through hole is formed in the resin molded product, can be easily taken out from the mold for molding the resin molded product, and the through hole is formed in the resin molded product. The work efficiency for forming the can be further improved.

According to one of the preferred embodiments of the present invention, the slide core has a tubular shape, and the first slide core is movable backward from the cavity surface of the molding cavity. A cavity for the molding cavity, which is configured to include a second slide core that is inserted through the inner hole of the first slide core and is capable of moving backward in the same direction as the first slide core. The mold for molding a resin molded product is used in which a part of the surface is composed of the first slide core and the second slide core, and the softening resin layer positioned in the molding cavity is After being pressed against and brought into close contact with the cavity surface of the molding cavity, the first slide core is moved backward from the cavity surface, while the second slide core is moved to the first slide core. The softening resin layer, which is moved further backward than the moving position of the ride core and is brought into close contact with the first cavity surface forming portion of the first slide core forming a part of the cavity surface of the molding cavity, The first slide core contact portion is stretched and thinned so that a space is formed between the one slide core contact portion and the mold.

In the case where the through-hole forming method for a resin molded product having such a structure is adopted, the adhesion portion (first slide core adhesion portion) of the softening resin layer to the first slide core is , Because it is stretched and thinned so that a space is formed between the contact portion and the mold,
Due to the presence of such a space, the thinned portion is quickly cooled and solidified as compared with the case where the adhesion portion of the softened resin layer to the first slide core is in contact with the mold and is stretched to be thinned. Not only that, but at that time, it tends to shrink more easily, so that the thinned portion can be cut more quickly and easily from the softened resin layer, and thus the resin molded article to be molded. Thus, the through hole having a shape corresponding to the slide core contact portion can be formed more reliably.

Further, according to the present invention, in the mold for molding a resin molded product used in the method for forming a through hole of a resin molded product as described above, a molding cavity having a shape corresponding to the resin molded product to be molded is formed. A mold body having the mold body, and a slide core assembled to the mold body so as to be able to move backward from the cavity surface of the molding cavity, wherein the slide core has the resin molding in the molding cavity of the mold body. At the position corresponding to the through hole forming part of the product,
A part of the cavity surface of the molding cavity is formed, and a cavity surface forming portion of the slide core forming a part of the cavity surface has a shape corresponding to a through hole formed in the resin molded product. It is also a characteristic that it is configured to have.

That is, in the mold for molding a resin molded product according to the present invention, the slide core movable backward from the cavity surface of the molding cavity corresponds to the through hole forming portion of the resin molded product in the molding cavity. The shape and size of the through-hole to be formed from the position where the through-hole to be formed has a shape corresponding to the through-hole and has a cavity surface forming portion that constitutes a part of the cavity surface of the molding cavity. When changing the height, it is only necessary to change the shape and size of the cavity surface constituting portion of the slide core without changing the structure of the mold body.

Therefore, in the mold for molding a resin molded product according to the present invention, the desired shape and size of the molded resin product can be obtained without complicating the overall structure of the mold. Since the through holes can be easily formed, the through holes can be extremely advantageously applied to the above-described method of forming through holes in a resin molded product.

According to one of the advantageous aspects of the mold for molding a resin molded product according to the present invention, the slide core has a tubular shape and is moved backward from the cavity surface of the molding cavity. The first slide core that is made possible and is inserted through the inner hole of the first slide core, and moves backward in the same direction as the first slide core and at a distance longer than the first slide core. A part of the cavity surface of the molding cavity at a position corresponding to the through hole forming portion of the resin molded product in the molding cavity of the mold body while including a second slide core enabled. Is a first cavity surface forming part in the first slide core which is composed of the first slide core and the second slide core, and further constitutes a part of the cavity surface. And the second cavity surface constituting portion of the second slide core are configured to form a shape corresponding to the through hole formed in the resin molded product. Even for a resin molding product molding die, without changing the structure of the die body, the first cavity surface forming portion of the first slide core and the second cavity surface forming portion of the second slide core By changing the shape and size of the part, it is possible to easily form through holes of the desired shape and size in the resin molded product. Can be applied extremely advantageously.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION In order to more specifically clarify the present invention, some embodiments of the present invention will be described in detail below with reference to the drawings.

First, FIG. 1 schematically shows an example of a vacuum molding die as a resin molding molding die which is preferably used when a through hole is formed in a resin molding according to the present invention. It is shown. As is clear from this figure, the vacuum forming mold 10 is configured to include a mold body 12 and a slide core 14.

Further, the mold body 12 constituting the vacuum molding mold 10 has a female mold shape having a recess opening to the outside, and the recess is a resin molded product to be molded. The molding cavity 16 has a corresponding shape.

On the other hand, the slide core 14 is composed of the mold body 12
In the cavity surface forming portion 18 exposed in the molding cavity 16 of the molding cavity 16, a part of the cavity surface 20 of the molding cavity 16 is formed and assembled to the mold body 12, and the molding cavity 16 is formed. It is configured so as to be slidable in the direction of retracting from the cavity surface 20. Although not clearly shown in FIG. 1, the slide core 14 has a round bar shape, and the cavity surface forming portion 18 has a circular shape.

The mold body 12 is provided with a plurality of suction holes 22a which open into the molding cavity 16 and communicate the inside and outside of the molding cavity 16, and the slide core 14 has a plurality of suction holes 22a. Also, one suction hole 22b having the same structure as the plurality of suction holes 22a is provided. Although not shown, the suction holes 22a and 22b are both connected to a suction device such as a vacuum pump through a suction pipe at the opening on the side opposite to the molding cavity 16 side. .

In this way, in the vacuum molding die 10, the air in the molding cavity 16 is sucked through the suction holes 22a and 22b in accordance with the operation of the suction device (not shown), which will be described later. As described above, the softening resin layer 28, which is located in the molding cavity 16 and gives the intended resin molded product, is sucked toward the cavity surface 20 side of the molding cavity 16 and is brought into close contact with the cavity surface 20. (See Figure 3).

The vacuum molding die 10 having such a structure is used, and it is advantageous that the desired resin molded product 24 is molded as shown in FIGS. 2 to 6. At the same time, the through hole 40 is formed in the molded resin product 24.

That is, first, as shown in FIG.
The softened resin layer 28 made of a heated and softened resin sheet is placed on the mold body 12 so as to cover the opening of the molding cavity 16 to the outside.

Next, under such an arrangement state of the softened resin layer 28, a suction device (not shown) is operated to remove air between the cavity surface 20 of the molding cavity 16 in the mold body 12 and the softened resin layer 28. , The mold body 12
Suction is performed through a plurality of suction holes 22a provided in the slide core 14 and one suction hole 22b formed in the slide core 14. As a result, a suction force for sucking the softening resin layer 28 toward the cavity surface 20 side of the molding cavity 16 is applied to the softening resin layer 28, and as shown in FIG.
The softening resin layer 28 is brought into close contact with the cavity surface 20 and the cavity surface constituting portion 18 of the slide core 14 which constitutes a part of the cavity surface 20. That is, here, the pressing force that presses the softened resin layer 28 against the cavity surface 20 of the molding cavity 16 is exerted by the suction force generated by the operation of the suction device.

Thereafter, as shown in FIG. 4, the slide core 14 is moved from the cavity surface 20 of the molding cavity 16 to a predetermined position with the softening resin layer 28 being in close contact with the cavity surface constituting portion 18 of the slide core 14. Move backward by the distance of. That is, the slide core 14 is slidably moved with respect to the mold body 12 in a state where the suction device is continuously operated to maintain the action of the suction force on the softened resin layer 28, and the slide core 14 is moved. Together with the cavity surface forming portion 18
The slide core contact portion 30 of the softened resin layer 28 that is brought into close contact with is retracted from the cavity surface 20 of the molding cavity 16 by a predetermined distance. Then, as a result, the slide core contact portion 30 in the softening resin layer 28
The outer peripheral edge portion of the slide core 14 is stretched in the moving direction of the slide core 14 to be thinned, and thus the entire slide core contact portion 30 has a depth having the same dimension as the moving distance of the slide core 14, The portion 30 has a recessed shape including a side wall portion 32 constituted by a thinned outer peripheral edge portion and a bottom wall portion 34 constituted by an inner peripheral portion thereof.
At this time, in the slide core contact portion 30, the recess-shaped side wall portion 32 is brought into contact with the sliding portion of the slide core 14 in the mold body 12, while the recess-shaped bottom wall portion 34. Is positioned in a state of being closely attached to the cavity surface constituting portion 18 of the slide core 14, and the recessed opening 36 is further positioned so that the slide core closely contacting portion 30 is brought into close contact with the cavity surface constituting portion 18 of the slide core 14. In the side wall portion 32 at the peripheral edge of the opening, the connection portion 38 with the softening resin layer 28 that is closely attached to the cavity surface 20 of the molding cavity 16 has a circular shape corresponding to that of the other portion. Then, it will be the thinnest and constructed.

Then, the mold body 12 and the slide core 14 are cooled in the same manner as in the conventional case, and the mold body 1 is cooled.
2 and the softening resin layer 28 which is brought into close contact with the cavity surface 20 of the molding cavity 16 and the cavity surface forming portion 18 of the slide core 14,
The slide core contact portion 30 that is brought into contact with the sliding portion of the slide core 14 in the mold body 12 is cooled and solidified. At that time, as described above, the slide core contact portion 30 is
Connection part 3 with the softening resin layer 28 that is brought into close contact with the cavity surface 20 of the molding cavity 16 in the mold body 12.
8, the connecting portion 38 of the slide core contact portion 30 is cooled and solidified first, and the shrinkage caused by the cooling causes the connecting portion 38 of the slide core contact portion 30 to be removed from the softening resin layer 28. Be disconnected. As a result, the softening resin layer 28 that is brought into close contact with the cavity surface 20 of the molding cavity 16 in the mold body 12 is cooled and solidified in the state where the slide core contact portion 30 is cut off, and thus the mold body is obtained. 12
The molding cavity 16 has a whole shape corresponding to the shape of the molding cavity 16 and a shape corresponding to the slide core contact portion 30 of the softening resin layer 28, in other words, a cavity surface constituting portion of the slide core 14. The resin molded product 24 having the circular through hole 40 corresponding to 18 is molded.

After that, as shown in FIG. 5, the resin molded product 24 molded as described above and at the same time having the through hole 40 formed therein is taken out from the molding cavity 16 of the mold body 12. At that time, similarly to the conventional case, the resin molded product 24 is released from the mold, for example, by sending compressed air through the plurality of suction holes 22a of the mold body 12.

Finally, as shown in FIG. 6, the slide core 14 is moved toward the mold surface of the mold body 12 toward the cavity surface forming position of the molding cavity 16.
The slide core 14 is slid relative to the slide core 14 to return the slide core 14 to a predetermined position so that a part of the cavity surface 20 of the molding cavity 16 is formed in the cavity surface constituting portion 18 of the slide core 14. In the vacuum forming mold 10, the slide core contact portion 30 that is cut from the softening resin layer 28 and cooled and solidified in the state of being in close contact with the cavity surface forming portion 18 of the slide core 14 is removed from the slide core 14. Take out from. In addition,
Such a slide core contact portion 30 is attached to the slide core 14
When removing from the suction hole 22b of the slide core 14
Compressed air may be sent in through.

As described above, in this embodiment, the molding cavity 1 having a shape corresponding to the resin molded product 24 to be molded.
For the mold body 12 having 6
A vacuum having a relatively simple structure in which the slide core 14 having the cavity surface forming portion 18 that constitutes a part of the cavity surface 20 of 6 is assembled so as to be slidable in the direction of retracting from the cavity surface 18. The molding die 10 is used, and the molding cavity 1 of the mold body 12 is used.
At the same time that the resin molded product 24 is molded in the resin 6, a through hole 40 having a shape corresponding to the cavity surface forming portion 18 of the slide core 14 is formed in the resin molded product 24. Thereby, the shape and size of the through hole 40 to be formed can be easily changed by simply changing the shape and size of the cavity surface constituting portion 18 of the slide core 14 in the vacuum molding die 10. Therefore, the through hole 40 having a desired shape and size can be extremely easily formed in the resin molded product 24 to be molded without making the structure of the vacuum molding die 10 complicated. You can do it.

Moreover, in this embodiment, the slide core contact portion 30 of the softening resin layer 28, which is brought into close contact with the cavity surface constituting portion 18 of the slide core 14, has a predetermined distance from the cavity surface 20 of the molding cavity together with the slide core 14. The outer peripheral edge portion of the slide core contact portion 30 is stretched in the same direction as the moving direction of the slide core 14 to be thinned by further retracting the slide core 30, and is cut from the softening resin layer 28 by further cooling and solidifying. Is
Since the through hole 40 is formed in the resin molded product 24 that is molded by the above method, such a slide core contact portion 30 is likely to enter the inside of the softened resin layer 28 after cutting. Can be advantageously prevented,
Further, as a result, it is possible to effectively prevent resin waste generated when the through hole 40 is formed from remaining in the resin molded product 24 after the through hole 40 is formed.

Therefore, in this embodiment, the manufacturability of the vacuum molding die 10 is deteriorated or the manufacturability of the vacuum molding die 10 is deteriorated as the shape and size of the through hole 40 formed in the resin molded product 24 is changed. It is possible to effectively prevent the manufacturing cost from rising, and it is unnecessary to take out the resin waste generated by the formation of the through holes 40 from the resin molded product 24 after the resin molded product 24 is molded. As a result, both the economical efficiency and workability in forming the through hole 40 in the resin molded product 24 can be effectively enhanced.

Further, in this embodiment, after the molded resin molded product 24 is taken out from the molding cavity 16 of the mold body 12, the slide core 14 is moved toward the cavity surface forming position of the molding cavity 16. Is the mold body 1
The slide core contact portion 30 that is slid with respect to 2, removed from the softening resin layer 28, and cooled and solidified in a state of being in close contact with the cavity surface constituting portion 18 of the slide core 14 is removed from the slide core 14. The slide core contact portion 30 can be easily taken out from the vacuum molding die 10 because it is urged to be taken out from the vacuum molding die 10. The workability for forming the through hole 40 in the molded product 24 can be further improved.

By the way, in the above embodiment, the slide core 14 made of one member, which has the cavity surface forming portion 18 forming a part of the cavity surface 20 of the molding cavity 16, is provided with respect to the mold body 12. The cavity surface 2
The vacuum forming mold 10 was constructed so as to be slidably moved in the direction of retreating from 0, but the slide core has a divided structure composed of two members, and these two members form a molding cavity. It is also possible to configure so that it can be moved backward from the cavity surface.

Specifically, as shown in FIG. 7, the vacuum molding die 41 used here has a molding cavity 16
And a first slide core 42 and a second slide core 44 assembled to the mold body 12
It is comprised including. The first slide core 42 has a cylindrical shape, and is arranged so as to be slidable by a predetermined distance in a direction of retracting from the cavity surface 20 of the molding cavity 16 in the mold body 12. On the other hand, the second slide core 44 has a round bar shape, is inserted into the inner hole of the first slide core 42, and is in the same direction as that of the first slide core 42 and in the first slide core 42. The slide core 42 is arranged so as to be slidable over a distance longer than the movement distance of the slide core 42. Then, the first slide core 42 and the second slide core 44
At one end face in the moving direction of the molding cavity 1
6 exposed to the inside of the molding cavity 1
6 constitutes a part of the cavity surface 20, and the one end surface of the first slide core 42 is
The one end surface of the second slide core 44 is the second cavity surface forming portion 48 while the first cavity surface forming portion 46 is the first cavity surface forming portion 46. Incidentally, in FIG. 7 and FIGS. 8 to 13 to be described later, members and parts having the same structure as that of the above-described embodiment are denoted by the same reference numerals as those of the above-mentioned embodiment, respectively, and Detailed description is omitted.

In order to mold a predetermined resin molded product 24 and simultaneously form the through hole 40 in the resin molded product 24 by using the vacuum molding die 41 having such a structure, Advantageously, first of all, as in the previous embodiment, FIG.
As shown in FIG. 9, after the softening resin layer 28 is placed on the mold body 12, as shown in FIG. 9, a suction device (not shown) is operated to move the mold body 12 and the second slide. By sucking air in the molding cavity 16 through the suction holes 22a and 22b provided in the core 44, the softening resin layer 28 is brought into close contact with the cavity surface 20 of the molding cavity 16.

Next, as shown in FIG. 10, the first cavity surface constituting portion 4 of the first slide core 42 is formed.
6 and the second slide surface 44 of the second slide core 44, the first slide core 42 is moved a predetermined distance from the cavity surface 20 of the molding cavity 16 while the softening resin layer 28 is in close contact. While moving backward, the second slide core 44 is moved further backward than the moving position of the first slide core 42 so as to be in close contact with the first cavity surface constituting portion 46 of the first slide core 42. The first slide core contact portion 50 of the softened resin layer 28 that has been pressed and the second slide core of the softened resin layer 28 that has been pressed into contact with the second cavity surface constituting portion 48 of the second slide core 44. Adhesion part 5
2 and the first and second cavity surface constituting portions 4
6, 48 together with the cavity surface 20 of the molding cavity 16
From each to a predetermined distance.

As a result, the entire first slide core contact portion 50 and the outer peripheral edge portion of the second slide core contact portion 52 are covered with the first slide core 42 and the second slide core 44.
In the moving direction of the first slide core and the second slide core contact portion 52 to reduce the wall thickness.
As a whole, it has a depth of the same dimension as the moving distance of the second slide core 44, and the outer periphery of the first slide core contacting portion 50 and the second slide core contacting portion 52 which are thinned as a whole. And a bottom wall portion 56 formed by the inner peripheral portion of the second slide core contact portion 52.

Further, in particular, here, the first slide core close contact portion 50 and the second slide core close contact portion 52, which are in the shape of a recess as a whole, are formed in the recessed side wall portion 54 at the first position. The opening-side portion constituted by the entire slide core contacting portion 50 is made to face the sliding portion of the first slide core 42 in the mold body 12 with a predetermined space 57 interposed therebetween, while the second portion Slide core adhesion part 52
The bottom side portion formed by the outer peripheral edge portion of the second slide core 42 is brought into contact with the inner wall portion of the first slide core 42, and the recess formed by the inner peripheral portion of the second slide core contact portion 52. The shaped bottom wall portion 56 is positioned in a state of being brought into close contact with the second cavity surface constituting portion 48 of the second slide core 44. Furthermore, in the first and second slide core contact portions 50 and 52, the recess-shaped opening 58 is provided in the first slide core contact portion 5.
0 and the second slide core contact portion 52 are brought into close contact with each other, corresponding to the first cavity surface forming portion 46 of the first slide core 42 and the second cavity surface forming portion 48 of the second slide core 44. In the side wall portion 54 at the peripheral edge portion of the opening, the connection portion 60 with the softening resin layer 28 that is brought into close contact with the cavity surface 20 of the molding cavity 16 is formed in comparison with other portions. It will be the thinnest and most constructed.

Then, after that, in the same manner as in the above-mentioned embodiment, the mold body 12 and the first and second slide cores 42,
44 and the softening resin layer 28 that is brought into close contact with the cavity surface 20 of the molding cavity 16 in the mold body 12, and the first and second slide core contact portions 50, 5
2 and are cooled and solidified. At that time, as described above, the first slide core contact portion 50 and the second slide core contact portion 52 are
Are arranged in the recess-shaped side wall 54 on the side of the opening with a space 57 between them and the mold body 12, and the connecting portion 60 of such a part is the thinnest. Since it is configured, the connecting portion 60 is first cooled and solidified, and is cut from the softened resin layer 28 by contraction caused by the cooling. As a result, the softening resin layer 28 that is brought into close contact with the cavity surface 20 of the molding cavity 16 in the mold body 12 is cooled and solidified with the first and second slide core contact portions 50 and 52 removed. Thus, the mold cavity 16 of the mold body 12 has an overall shape corresponding to the shape of the mold cavity 16 and the first and second slide core contact portions 50, 52 of the softening resin layer 28. In other words, in other words, a circular shape corresponding to the first cavity surface forming portion 46 of the first slide core 42 and the second cavity surface forming portion 48 of the second slide core 44. The resin molded product 24 having the holes 40 is molded.

After that, as shown in FIG. 11, the resin molded product 24 having the through holes 40 formed therein is taken out from the molding cavity 16 of the mold body 12 in the same manner as in the above embodiment.

Next, as shown in FIG. 12, only the second slide core 44 is inserted into the inner cavity of the first slide core 42, and the molding cavity 16 in the mold body 12 is molded.
Of the first and second slide cores 40 and 52, which have been cut and solidified by being moved from the softening resin layer 28 by advancing toward the cavity surface forming position of the first slide core 42. Then, as shown in FIG. 13, the first slide core 42 and the second slide core 44 are integrally formed toward the cavity surface forming position of the molding cavity 16 in the mold body 12. The cavity surface 2 of the molding cavity 16 is moved forward and moved at the first and second cavity surface constituting portions 46 and 48 of the first and second slide cores 42 and 44.
The first slide core 42 so that a part of 0 is formed.
And the second slide core 44 are returned to predetermined positions, and the first slide core contact portion 50 and the second slide core contact portion 52 are removed from the first slide core 42 and the second slide core 44. After being removed, it is taken out from the vacuum forming die 41.

As described above, also in this embodiment, the softening resin layer 28 is formed on the first slide core 42 in the first cavity surface forming portion 46 and in the second slide core 44 in the second cavity surface forming portion. The first slide core 42 and the second slide core 44 are brought into close contact with the cavity surface 2 of the molding cavity 16 under the state of being closely attached to the cavity surface 2 of the molding cavity 16.
The first slide core contact portion 50 and the second slide core contact portion 5 in the softened resin layer 28 are moved backward from 0.
2 is stretched to reduce the thickness, and the thinned portion is cooled and solidified to cut off the first and second slide core contact portions 50 and 52 from the softened resin layer 28, thereby forming the resin molded product 24. At the same time that the resin is molded, the first cavity surface forming portion 46
Since the through hole 40 having a shape corresponding to the second cavity surface forming portion 48 and the second cavity surface constituting portion 48 is formed, the structure of the vacuum forming die 41 is simply complicated without any complicated structure. First and second slide cores 42, 4
4, the first and second cavity surface constituting portions 46,
The through hole 40 having a desired shape and size can be extremely easily formed in the resin molded product 24 to be molded simply by changing the shape and size of the through hole 40. It is effective that the first slide core contact portion 50 and the second slide core contact portion 52, which are resin scraps generated by the formation of the above, remain inside the resin molded product 24 after the formation of the through hole 40. Therefore, the same effects as those of the above-described embodiment can be enjoyed very effectively.

In particular, in this embodiment, the molding cavity 1 of the first and second slide cores 42 and 44 is
In the first slide core close contact part 50 and the second slide core close contact part 52 which are stretched and thinned by the backward movement of the cavity 6 from the cavity surface 20, the first slide core close contact part 50 is The mold body 12 is arranged in a state where a predetermined space 57 is formed between the mold body 12 and the sliding portion of the first slide core 42, and is cooled and solidified in this state, whereby the first slide core contact portion 50. And the second slide core contact portion 52 are cut from the softened resin layer 28 that is brought into close contact with the cavity surface 20 of the molding cavity 16 at the connecting portion 60 of the first slide core contact portion 50. Therefore, as in the above-described embodiment, such a cut portion from the softened resin layer 28 (the connecting portion 38 of the slide core contact portion 30) is brought into contact with the mold (10). In comparison with the case where the first slide core contacting portion 50, which is a cutting site, is quickly cooled and solidified, and more easily contracts as compared with the case where the first slide core contacting portion 50 is arranged in the closed state. Slide core contact part 5
0 and the second slide core contact portions 50, 52 can be cut more quickly and easily from the softening resin layer 28, so that the first and second slide cores can be removed from the resin molded product 24. Through hole 40 having a shape corresponding to the contact portions 50 and 52
Can be formed even more reliably.

Further, in the present embodiment, only the second slide core contact portion 52 which is stretched and thinned as described above constitutes the inner wall portion which constitutes the inner hole of the first slide core 42. When the slide core (14) composed of one member is moved backward from the cavity surface 20 of the molding cavity 16 as in the above embodiment, the slide core adheres to the slide core closely. Division (3
0) compared with the case where the whole is contacted with the die body 12, the second slide core contact portion 52
Can be brought into contact with the inner wall portion of the first slide core 42 with a small area, so that the second slide core contact portion 52 in the softened state can contact the inner wall portion and the second slide core 42. Can be suppressed as much as possible, and, as described above, the first slide core contact portion 50 is not connected to the sliding portion of the first slide core 42 in the mold body 12. Since it is positioned via the space 57, the first slide core contact portion 50 in the softened state may get into the gap between the first slide core 42 and the mold body 12. It can be well prevented, and thus a smooth operation state of the first and second slide cores can be well ensured during the forward movement of the molding cavity 16 toward the cavity surface 20. Then, as a result, the first slide core contact portion 50 and the second slide core contact portion 52, which are resin scraps generated when the through hole 40 is formed in the resin molded product 24, are removed from the inside of the vacuum molding die 41. It can be taken out more easily and reliably.

The two embodiments of the present invention have been described in detail above, but these are literal examples and the present invention should not be construed as being limited to such specific examples.

For example, in the above-described embodiment, the molding cavity 16 provided in the mold body 12 of the vacuum molding molds 10 and 41 has a concave shape, but the shape of the molding cavity 16 is not limited to this. It is not limited to the above, but may be appropriately determined according to the shape of the resin molded product 24 to be molded.

In the above embodiment, the mold body 1
Slide cores (14, 42, 44) assembled to 2
Although it is composed of one or two members, it is of course possible to compose it of three or more members.

Furthermore, such a slide core (14,
42, 44) has a round bar shape in the first embodiment, while the first slide core 42 has a cylindrical shape in the second embodiment, and the second slide core 44 has a cylindrical shape. The slide cores (14, 42, 44) are configured to have a round bar shape, and the cavity surface constituting portions (18, 46, 48) of the slide cores (14, 42, 44) have a circular shape. However, the present invention is not limited to this, and any configuration is possible as long as each cavity surface constituting portion (18, 46, 48) has a shape corresponding to the through hole 40 formed in the resin molded product 24. The shape does not matter, and the size thereof can be appropriately determined according to the size of the through hole 40.

Further, in the above embodiment, the mold body 12 and the slide cores (14, 42, 44) are cooled, so that the softening resin layer 28 which is brought into close contact with the cavity surface 20 of the molding cavity 16 and the slides. Core (1
4, 42, 44) cavity surface constituting portion (18, 4)
6, 48) and the slide core contact portions (30, 50, 52) that are brought into close contact with each other, are simultaneously cooled and solidified, and the slide core contact portions (30, 50, 52) are also solidified.
Connection part (38, 60) with the softening resin layer 28 in
Was made to contract from the softened resin layer 28, but the mold body 12 and each slide core (1
Before cooling each of the slide cores (4, 42, 44), each slide core contact portion (30, 50, 52) is cooled and solidified by some method, or they are naturally cooled and solidified by contact with air. Slide core contact part (30, 50,
The connecting portion (38, 60) of 52) may be contracted so as to be cut from the softening resin layer 28.

Further, in the second embodiment, when the first and second slide core contact portions 50 and 52 that have been solidified by cooling are removed from the first and second slide cores 42 and 44, first, In the inner hole of the first slide core 42, only the second slide core 44 is moved forward, and then the first slide core 42 and the second slide core 44 are moved to the cavity surface forming position of the molding cavity 16. I was trying to move forward integrally towards
Of course, it is also possible to simultaneously move the first slide core 42 and the second slide core 44 forward without performing such stepwise forward movement.

In addition, in the above embodiment, the resin molded product 2 is manufactured by the vacuum molding method using the vacuum molding dies 10 and 41.
Although a specific example of applying the present invention to the method for molding No. 4 is shown, the present invention can be applied to the softening resin layer positioned in the molding cavity of the mold such as the blow molding method or the pressure molding method. It can be advantageously applied to a method of molding a desired resin molded product by applying a pressing force to bring the softened resin layer into close contact with the cavity surface of the molding cavity and then cooling and solidifying the softened resin layer. Of course,

In addition, although not enumerated one by one, the present invention
Based on the knowledge of those skilled in the art, various changes, modifications, improvements and the like can be implemented in an embodiment,
It goes without saying that all such embodiments are included within the scope of the present invention, without departing from the spirit of the present invention.

[0059]

As is apparent from the above description, according to the method for forming a through hole of a resin molded product according to the present invention, a resin molded product to be molded can be formed without complicating the structure of the entire mold. On the other hand, it is possible to easily form a through hole having a desired shape and size, and it is possible to advantageously prevent resin waste generated by the formation of the through hole from remaining inside the resin molded product. Yes, thereby, it is possible to advantageously suppress the increase in the manufacturing cost of the mold due to the change of the mold structure by changing the shape and size of the through hole,
It is possible to eliminate the work of removing resin scraps from the inside of the resin molded product after forming the through holes, and as a result, when forming the through holes in the resin molded product, the economy and workability superior to those in the past are extremely high. It can be effectively exerted.

Further, the mold for molding the resin molded product according to the present invention can be constructed with a relatively simple structure, and the resin molding can be molded without any complicated structure of the entire mold. Through-holes having a desired shape and size can be easily formed in the product, and thus it can be extremely advantageously applied to the above-described method for forming through-holes in resin molded products.

[Brief description of drawings]

FIG. 1 is a longitudinal cross-sectional explanatory view of an essential part showing an example of a metal mold for molding a resin molded product which is used when a resin molded product is molded according to the method of the present invention and at the same time a through hole is formed in the resin molded product is there.

FIG. 2 is an explanatory view showing one step in the method for forming a through hole of a resin molded product according to the present invention, in which a softening resin layer is arranged in the molding cavity of the resin molded product molding die shown in FIG. Indicates.

FIG. 3 is an explanatory view showing another step in the method for forming a through hole of a resin molded product according to the present invention, in which a softening resin is formed on the cavity surface of the molding cavity of the resin molded product molding die shown in FIG. The state where the layers are brought into close contact is shown.

FIG. 4 is an explanatory view showing still another step in the method of forming a through hole of a resin molded product according to the present invention, in which the cavity surface forming portion of the slide core of the resin molded product molding die shown in FIG. 1 is softened. With the resin layer in close contact,
The state where the slide core is moved backward from the cavity surface of the molding cavity is shown.

5 is an explanatory view showing still another step in the method for forming a through hole in a resin molded product according to the present invention, in which a resin molded product is molded from the molding cavity of the resin molded product molding die shown in FIG. 1. FIG. The state where the product is taken out is shown.

6 is an explanatory view showing still another step in the method for forming a through hole of a resin molded product according to the present invention, in which a portion cut from the softening resin layer is a metal mold for molding the resin molded product shown in FIG. The state after being removed from the slide core is shown.

FIG. 7 corresponds to FIG. 1, which shows another example of a resin-molded-product-molding die used for forming a through hole in the resin-molded product at the same time as molding the resin-molded product according to the method of the present invention. It is a figure.

FIG. 8 is a diagram corresponding to FIG. 2, showing one step in carrying out the method for forming a through hole of a resin molded product according to the present invention using the mold for molding a resin molded product shown in FIG. 7.

FIG. 9 is a diagram corresponding to FIG. 3, showing another step when carrying out the method for forming a through hole of a resin molded product according to the present invention, using the mold for molding a resin molded product shown in FIG. 7.

10 is a view corresponding to FIG. 4, showing still another step in carrying out the method for forming a through hole in a resin molded product according to the present invention, using the resin molding product molding die shown in FIG. 7; .

FIG. 11 is a view corresponding to FIG. 5, showing still another step when carrying out the method for forming a through hole of a resin molded product according to the present invention, using the resin molding product molding die shown in FIG. 7. .

FIG. 12 is an explanatory view showing still another step when carrying out the method for forming a through hole of a resin molded product according to the present invention using the mold for molding a resin molded product shown in FIG. The process in the middle of removing the part excised from the layer from the slide core is shown.

13 is a view corresponding to FIG. 6 showing still another step when carrying out the method for forming a through hole of a resin molded product according to the present invention, using the mold for molding a resin molded product shown in FIG. 7. .

[Explanation of symbols]

10, 41 Vacuum forming mold 12 Mold body 14 Slide core 16 Molding cavity 18 Cavity surface constituting part 20 Cavity surface 24 Resin molded product 28 Softening resin layer 30 Slide core contact part 40 Through hole 42 First slide core 44th Second slide core 46 First cavity surface forming portion 48 Second cavity surface forming portion 50 First slide core close contact portion 52 Second slide core close contact portion 57 Space

Claims (5)

[Claims] 1. A resin molding comprising a slide core which constitutes a part of a cavity surface of a molding cavity having a shape corresponding to a resin molded article to be molded and which is configured to be movable backward from the cavity surface. After the softening resin layer is positioned in the molding cavity of the mold using a product molding die, a pressing force for pressing the softening resin layer against the cavity surface of the molding cavity is applied to the softening resin layer. By adding, the softening resin layer is brought into close contact with the cavity surface of the molding cavity, and then, while the softening resin layer is brought into close contact with the cavity surface constituting portion of the slide core, the slide core is moved backward. Thus, the outer peripheral edge portion of the slide core contact portion of the softened resin layer that is brought into close contact with the cavity surface constituting portion of the slide core is stretched to be thinned. The slide core adhesion part is cut off from the softening resin layer at such a thinned portion by further tightening by cooling and solidification, and the resin molded article to be molded has a shape corresponding to the slide core adhesion part. A method for forming a through hole in a resin molded product, which comprises forming a hole. 2. A resin molded product having the through hole formed therein is taken out from a molding cavity of a mold for molding the resin molded product, and then the slide core is moved forward toward a position forming a cavity surface of the molding cavity. The method for forming a through hole in a resin molded article according to claim 1, wherein the slide core contact portion cut off from the softened resin layer is thereby removed from the slide core. 3. The slide core has a tubular shape,
Also, the first slide core, which is movable backward from the cavity surface of the molding cavity, and the first slide core, which is inserted into the inner hole of the first slide core, can be moved backward in the same direction as the first slide core. And a second slide core formed into the resin mold, and a part of the cavity surface of the molding cavity is composed of the first slide core and the second slide core. Using a molding die, the softening resin layer positioned in the molding cavity is pressed against the cavity surface of the molding cavity to bring them into close contact, and then the first slide core is moved backward from the cavity surface. The second slide core is moved further backward than the moving position of the first slide core to form a part of the cavity surface of the molding cavity. The first slide core contact portion so that a space is formed between the mold and the first slide core contact portion of the softened resin layer that is brought into close contact with the first cavity surface constituting portion of the id core. The method for forming a through hole in a resin molded product according to claim 1 or 2, wherein the resin is stretched to be thinned. 4. A mold for molding a resin molded product, which is used in the method for forming a through hole of a resin molded product according to any one of claims 1 to 3, and has a shape corresponding to the resin molded product to be molded. Of the mold cavity, and a slide core assembled to the mold body so as to be movable backward from the cavity surface of the mold cavity, the slide core being the mold cavity of the mold body. At a position corresponding to the through hole forming portion of the resin molded product in
A part of the cavity surface of the molding cavity is formed, and a cavity surface forming portion of the slide core forming a part of the cavity surface has a shape corresponding to a through hole formed in the resin molded product. A mold for molding a resin molded product, which is configured to have. 5. The slide core has a tubular shape,
And a first slide core that can be moved backward from the cavity surface of the molding cavity, and is inserted through an inner hole of the first slide core so as to extend in the same direction as the first slide core. At a position corresponding to the through-hole forming portion of the resin molded product in the molding cavity of the mold body while being configured to include a second slide core that can be moved backward at a distance longer than the slide core. , Part of the cavity surface of the molding cavity is
The first slide core is composed of the first slide core and the second slide core, and further, the first cavity core forming portion of the first slide core constituting a part of the cavity surface and the second cavity of the second slide core. 5. The metal for molding a resin-molded product according to claim 4, wherein a shape corresponding to a through-hole formed in the resin-molded product is formed at the cavity surface forming portion of Type.