JPH081716A - Hollow molded article molding method and mold used therein - Google Patents

Abstract

(57) [Summary] [Purpose] A mold for molding hollow molded products that can be attached to a general-purpose injection molding machine with a single ejector and that allows easy removal of the resin sprue runner and hollow molded products. obtain. [Structure] The runner plate 40 provided between the slide die 3 and the fixed die 2 is moved in the horizontal direction, and the resin sprue runner portion 33 solidified in the primary sprue 43 is projected from the die 1 to move the movable die 4 The ejector plate 52 provided on the movable plate 10 side provided in the ejector box 53 is ejected by the ejector 54, and the resin sprue runner portion 35 and the hollow molded product 30 solidified in the secondary sprue 44 are ejected from the mold 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a hollow molded article made of synthetic resin and a mold used therefor, and more particularly to a method for molding a hollow molded article by an injection molding machine and an apparatus therefor. is there.

[0002]

2. Description of the Related Art The applicant of the present invention has previously proposed a method for molding a hollow molded article and a mold thereof (see Japanese Patent Publication No. 2-38377) shown in FIGS. This will be described with reference to the drawings.

That is, the method for molding the hollow molded article is as follows:
As shown in FIG. 14 (a), a split body 3 in which a hollow molded product is divided into two in a slide die 3 which is one die.
A male die 15 and a female die 16 for respectively molding 1 and 32 are provided, and the male die 15 is provided on the movable die 4 which is the other die.
And a female mold 16 are provided with a female mold 17 and a male mold 18, which are opposed to each other, and are formed between the male molds 15 and 18 and the female molds 17 and 16 which are opposed to each other. Molten resin is injected into the pair of cavities 19 and 20 formed by the injection machine 11 to mold the divided bodies 31 and 32, and then, as shown in FIG. Is separated from the slide mold 3, and one slide mold, the slide mold 3, is slid so that the divided bodies 31 and 32 remaining in the female dies 17 and 16 face each other, and the dies 3 and 4 are separated from each other. After these divided bodies are abutted against each other by mold matching, molten resin is injected to the peripheral edges of the abutting surfaces 31a and 32a, and the peripheral body resin 34 welds the divided bodies 31 and 32 to each other. I am configuring.

The mold for molding the hollow molded product is shown in FIG.
As shown in (a), a fixed die 2 having a single sprue 12, a slide die 3 that is moved along the fixed die 2 between two positions, and a die matching with the slide die 3. It is composed of a movable mold 4.

The fixed mold 2 is a bed 6 of the injection molding machine 5.
It is fixed to a fixed plate 7 which is integral with. A pedestal 8 having a horizontal arm 8a is erected on the upper surface of the fixed mold 2. Then, on the lower surface of the horizontal arm 8a, a slide cylinder 9 operated by hydraulic pressure or pneumatic pressure is provided.
Is attached. The piston rod 9 a of the cylinder 9 is connected to the upper surface of the slide die 3. In this way, the slide die 3 is slidable up and down between the position where the cylinder 9 is most extended and the upper position where the cylinder 9 is most contracted, while keeping the state in which the slide die 3 is in close contact with the surface of the fixed die 2. ing.

The movable die 4 is attached to a movable platen 10 which is supported on a bed 6 of an injection molding machine 5 so as to be horizontally movable. The movable platen 10 is moved back and forth with respect to the fixed platen 7 by a mold opening / closing device (not shown). In this way, the movable die 4 is moved back and forth between the die fitting position in which the movable die 4 is in close contact with the slide die 3 and the die opening position separated from the slide die.

The slide mold 3 is provided with a male mold 15 and a female mold 16 for molding divided bodies 31, 32 obtained by dividing the hollow molded product 30 into two, and at the two positions of the fixed mold 2. Sub-sprues 13 and 14 continuous to the sprue 12 are provided, and the movable die 4 has its male die 15 and female die 16 when the slide die 3 is at one position (see FIG. 14A). Are provided with a female die 17 and a male die 18, which face each other.
7 is arranged to face the female die 16 of the slide die 3 when the slide die 3 moves to the other position (see FIG. 14 (b)).
Is connected to the sprue 12 of the fixed mold 2 so as to communicate with the end edges of the female molds 16 and 17, and the divided body 31 is provided to the male molds 15 and 18. , 32 are provided with protrusions 24, 25 for forming the grooves 31b, 32b on the periphery of the abutting surfaces 31a, 32a.

After cooling and solidifying the divided bodies 31 and 32 shown in FIG.
The movable die 4 is separated from the slide die 3 as shown in FIG. When opening this mold, sprue 1 of mold 1
2. The resin sprue runner portion 33 solidified in the sub-sprue 13 and the inside 21 of the runner is projected from the mold, separated at the portions corresponding to the gates 22 and 23, and falls.

Further, after the peripheral edge resin 34 shown in FIG. 14 (b) is cooled and solidified, as shown in FIG. 15 (b), the movable mold 4 is slid again by the mold opening / closing device. Away from.

When the mold is opened, the hollow molded product 30 completed
The resin sprue runner portion 35 solidified in the sprue 12, the sub-sprue 14, and the runner 21 of the mold 1 is projected from the mold 1, and is separated and dropped at the portions corresponding to the gates 22 and 23.

[0011]

The resin sprue runner portion and the hollow molded product are taken out by ejecting the ejector provided on the movable plate side to which the movable mold is attached to the mold. In a general-purpose injection molding machine, the ejector is provided at one position on the movable plate side facing the sprue of the mold. In the production of the hollow molded article of the conventional example, the ejector operates twice. That is, the first time is for taking out the resin sprue runner portion, and the second time is for taking out the hollow molded product and the resin sprue runner. And, since the respective take-out conditions are different, there is a problem in the take-out method and device.

Further, if various molds are attached to one injection molding machine depending on the type of the hollow molded product, there arises a problem that they cannot be attached due to the ejector.

Therefore, the present invention can be applied to a novel method for molding a hollow molded product according to the type of the hollow molded product and an injection molding machine having a single ejector, and the resin sprue runner portion and the hollow molded product can be taken out. It is an object of the present invention to provide a mold used for molding a hollow molded product, which can be easily manufactured and whose gate dimensions can be optimized.

[0014]

According to the method of the present invention, a movable mold, which is one mold attached to a movable plate, is provided with a male mold and a female mold for molding a divided body obtained by dividing a hollow molded product into two parts. The slide mold, which is the other mold and is disposed in the slide mold guide that moves in the horizontal direction and moves between two positions, is provided with a female mold and a male mold that face the male mold and the female mold, respectively. In addition, using a set of molds, molten resin is injected from a primary sprue provided in the slide mold into a pair of cavities formed between the male mold and the female mold that face each other, and The body is molded, and then the movable die is separated from the runner plate provided between the fixed die and the slide die together with the slide die guide in which the slide die is arranged, and then the resin sprue runner portion is solidified in the primary sprue. The mold After protruding, and further separating the movable die and the slide die guide in which the slide die is arranged, slide the slide die so that the divided bodies left in each female die face each other, and each die is matched. As a result, after these divided bodies are abutted against each other, a molten resin is injected from a secondary sprue provided in a slide type on the peripheral edge of the abutting surface, and the divided peripheral bodies are welded together by the resin. There is.

More specifically, the runner plate provided between the fixed die and the slide die is separated from the fixed die, and the resin sprue runner portion solidified in the primary sprue is projected from the die.

More specifically, the ejector plate provided on the movable platen side of the movable mold is projected by a single ejector so that the resin sprue runner portion solidified in the secondary sprue and the hollow molded product are projected from the mold. I have to.

The mold according to the present invention includes a fixed mold having a single sprue, a slide type guide which moves in the horizontal direction, a slide type which moves between two positions in the slide type guide, and a slide type. Movable type to be matched
The runner plate is provided between the fixed die and the slide die and moves in the horizontal direction.
A male mold and a female mold are respectively provided for molding a divided body obtained by dividing the hollow molded product into two parts, and a primary sprue and a secondary sprue continuous with the sprue of the fixed mold at the two positions.
A second sprue is provided, and the movable mold is provided with a female mold and a male mold that respectively face the male mold and the female mold when the slide mold is in one position, and a pair of cavities are provided. When the female mold is formed so as to face the female mold of the slide mold when the female mold of the slide mold moves to the other position, and the primary sprue is continuous with the sprue of the fixed mold. The secondary sprue is adapted to communicate with the edge of the female mold when the secondary sprue is continuous with the fixed mold sprue. Further, a protrusion for forming a groove is provided on the peripheral edge of each butting surface of the divided body.

More specifically, a restraint means for restraining the slide type guide in which the slide die is arranged on the runner plate is provided, and the restraint means are arranged in the same horizontal direction of the runner plate and the slide type guide in which the slide die is arranged. It consists of a pin provided and a pulling jig having an elongated hole that is engaged with this pin.

More specifically, restraint means for restraining the runner plate to a fixed die is provided, and the restraint means is engaged with the pin provided in the same horizontal direction of the fixed die and the runner plate, respectively. And a pulling jig having a long hole. More specifically, the movable mold comprises a mold part having a male mold and a female mold, and an ejector box, and the ejector box includes a connection part attached to the movable plate and a mold part and the connection part. And an ejector plate provided in this gap. The ejector plate includes a resin sprue runner portion formed by filling a peripheral edge resin with a peripheral edge resin of each divided body, and each divided body. Have ejector pins for ejecting a hollow molded article formed by being welded to each other from the mold, and the ejector plate is operated by a single ejector.

According to the method of the present invention, a movable mold, which is one mold that moves between two positions along a guide plate attached to a movable plate, is formed with a male mold for molding a divided body obtained by dividing a hollow molded product into two. A female mold is provided, and a fixed mold, which is the other mold attached to the stationary plate, is provided with a female mold and a male mold that face the male mold and the female mold, respectively. , Molten resin is injected into a pair of cavities formed between the male mold and the female mold that face each other to mold each divided body, and then the movable mold is separated from the fixed mold to move the movable mold. After sliding, the divided bodies remaining in each female mold are opposed to each other, and the respective molds are matched to each other, but after these divided bodies are butted against each other, a molten resin is injected to the periphery of the butted surface. This peripheral part resin is used to It is to be welded to each other.

The mold according to the present invention is attached to a fixed platen, moves between two positions along a fixed plate having a single sprue and a guide plate attached to the movable platen, and is fitted to the fixed platen. A movable mold, wherein the movable mold is provided with a male mold and a female mold for molding a divided body obtained by dividing a hollow molded product into two, and a runner continuous to the sprue of the fixed mold at the two positions. The fixed mold is provided with a female mold and a male mold that respectively face the male mold and the female mold when the movable mold is at one position, and the female mold is the movable mold. Is arranged so as to face the female mold of the movable mold when it moves to the other position, and when the sprue is continuous with the runner of the movable mold, the sprue is communicated with the edges of the female mold. Being with, before Each male, projections are provided for forming a groove in the abutting surfaces periphery of said split body.

More specifically, the movable mold comprises a mold part having a male mold and a female mold, and an ejector box,
The ejector box includes a connecting portion that slides along a guide plate attached to a movable plate, an intermediate member that provides a fixed gap between the mold portion and the connecting portion, and an ejector plate that is provided in this gap. The ejector plate comprises an ejector plate having an ejector pin for ejecting a resin sprue runner portion formed by filling molten resin into each cavity for molding each divided body, and an abutting peripheral portion of each divided body. It consists of a resin sprue runner part filled with peripheral resin and ejector pins for ejecting hollow molded products formed by welding each divided body to each other, and both ejector plates,
Operated by a single ejector.

The mold according to the present invention comprises a fixed mold having a single sprue, a slide mold moved between two positions along the fixed mold, and a movable mold matched with the slide mold. The slide mold is provided with a male mold and a female mold that respectively mold a divided body obtained by dividing a hollow molded product into two parts, and a sub-sprue that is continuous with the sprue of the fixed mold at the two positions is provided. Cage,
The movable die is provided with a female die and a male die that respectively face the male die and the female die when the slide die is in one position, and the female die is in the other position. When moving, it is arranged so as to face the female mold of the slide type, and when the sub-sprue is in a state of being continuous with the sprue of the fixed type, it is made to communicate with the edge parts of these female molds. And each of the male molds is provided with a projection for molding a groove on the periphery of each butting surface of the divided body, and the movable mold is composed of a mold part having a male mold and a female mold and an ejector box, The ejector box is composed of a connecting portion that is connected to the movable plate, an intermediate member that provides a fixed gap between the mold portion and the connecting portion, and a cylinder that is provided in this gap. To mold each It consists of a cylinder that ejects the resin sprue runner part that fills the cavity with molten resin from the mold, and a cylinder that ejects the hollow molded product molded by filling the peripheral edge resin of the butted peripheral part of each divided body from the mold. There is.

In the mold according to the present invention, the selection of whether or not the resin sprue runner portion, in which each cavity is filled with the molten resin, is projected by a single ejector is selected.

[0025]

According to the method for molding a hollow molded article and the mold used therefor, the resin sprue runner solidified in the primary sprue is formed by a runner plate provided between the slide mold and the fixed mold. Protruding the part from the mold,
The ejector plate provided on the movable platen side of the movable die is projected by a single ejector, and the resin sprue runner portion solidified in the secondary sprue and each divided body are welded together to form a hollow molded product from the die. It is sticking out.

In the method for molding a hollow molded article and the mold used therein according to claims 10 to 12, two sets of ejector plates are used, while each cavity is formed in order to mold each divided body. A resin sprue runner part filled with molten resin is projected from the mold, and on the other hand,
A hollow spun product formed by welding the resin sprue runner portion formed by filling the peripheral edge portion of each divided body with a peripheral edge resin and each divided body is extruded from a mold. Both ejector plates operate with a single ejector.

In the mold for molding a hollow molded product according to the thirteenth aspect, two sets of cylinders are used, while each cavity is filled with a molten resin to mold each divided body. The resin sprue runner part is ejected from the mold, and on the other hand, the resin sprue runner part formed by filling the peripheral edge resin of the abutting edge of each divided body with each divided body is molded into a hollow molded product by molding. It sticks out of the mold. In this case, the ejector is not used.

In the mold for molding a hollow molded article according to the fourteenth aspect, a selection switch is used to select whether or not the resin sprue runner portion in which each cavity is filled with molten resin is projected by a single ejector. Is going by.

[0029]

Embodiments of the present invention will be described below with reference to the drawings. It should be noted that the same or equivalent parts as those of the conventional example are designated by the same reference numerals for description. (Embodiment 1) In the drawings, FIG. 1 is a longitudinal sectional view showing a molding die for a hollow molded article according to the present invention. 2 to 9 are vertical cross-sectional views showing the state of the mold in each step for explaining the method for molding a hollow molded product using this mold.

As is apparent from FIG. 1, the molding die 1 includes a fixed die 2, a runner plate 40, and a slide die 3.
And a movable die 4. The fixed mold 2 is fixed to a fixed platen 7 that is integral with the bed 6 of the injection molding machine 5. Slide type guide 41
A pedestal 8 having a horizontal arm 8a is erected on the upper surface of the. A slide cylinder 9 that is operated by hydraulic pressure or air pressure is attached to the upper surface of the horizontal arm 8a. An electric motor may be used instead of this cylinder. The piston rod 9 a of the cylinder 9 is connected to the upper surface of the slide die 3. In this way, the slide die 3 is slidable up and down between the lower position where the cylinder 9 is most extended and the upper position where the cylinder 9 is most retracted in the slide die guide 41.

The movable mold 4 is attached to a movable platen 10 which is supported on a bed 6 of an injection molding machine 5 so as to be horizontally movable. The movable platen 10 is moved back and forth with respect to the fixed platen 7 by a mold opening / closing device (not shown). Thus, the movable die 4 is provided between the slide die 3, the runner plate 40 (which will be described later) and the fixed die 2 in a mold fitting position, and the die open position in which the slide die 3, the runner plate 40 and the fixed die 2 are separated from each other. So, it can be moved back and forth.

The fixed mold 2 has an injection machine 11 at the center thereof.
A sprue bush 42 having a sprue 12 that guides the molten resin injected from is provided. A runner plate 40 is slidably fitted to a sprue bush 42 between the fixed die 2 and the slide die 3.

The slide die 3 has a primary sprue 43 (see FIG. 2) which is continuous with the sprue 12 when the slide die 3 is in the lower position and a lower sprue 12 which is continuous with the sprue 12 when the slide die 3 is moved to the upper position. Secondary sprue 44 (Fig. 6)
See) and are provided.

A male mold 15 and a female mold 16 are provided on the mold matching surface of the slide mold 3. This male type 15
Is for molding the inner surface side of one of the divided bodies obtained by dividing the target hollow molded product in two, and the female die 16 is for forming the outer surface side of the other divided body. On the other hand, the mold matching surface of the movable mold 4 is provided with a female mold 17 and a male mold 18, which are opposed to the male mold 15 and the female mold 16, respectively, when the slide mold 3 is at the lower position. The female die 17 is for molding the outer surface side of one of the divided bodies, and the male die 18 is for molding the inner surface side of the other divided body. And
The female die 17 on the movable die 4 side faces the female die 16 on the slide die 3 side when the slide die 3 is at the upper position.

Thus, when the slide die 3 is at the lower position and the movable die 4 is matched with this, the male dies 15, 18 are provided between the slide die 3 and the movable die 4.
And a pair of cavities 19 and 20 surrounded by the female molds 17 and 16, respectively.
At this time, the primary sprue 43 formed on the slide die 3 and the gates 26, 26a communicate with the central portions of the male die 15 and the female die 16, that is, the cavities 19, 20 thereof. Further, when the slide die 3 is at the upper position and the movable die 4 is aligned with this, the female dies 16, 17 of the slide die 3 and the movable die 4 are formed.
Are abutted against each other, and the lower secondary sprue 44 communicates with the end edges of the female dies 16 and 17 through the runner 21 and the gate 27 of the movable die 4.

At the periphery of each male mold 15 and 18, each female mold 1
Small protrusions 24 fitted on the peripheral edges of 7, 16
25 are provided.

Restraining means 71 for restraining the slide type guide 41 having the slide die 3 arranged on the runner plate 40 is provided. The restraint means 71 includes a slide type guide 41 in which the runner plate 40 and the slide type 3 are arranged.
Pins 45 provided in the same horizontal direction of
46, and a pulling jig 46 having an elongated hole 46a engaged with the pins 45, 46. Further, restraint means 72 for restraining the runner plate 40 to the fixed mold 2 is provided. The restraint means 72 includes pins 65 and 66 provided in the same horizontal direction of the fixed die 2 and the runner plate 40, respectively, and a pulling jig 67 having elongated holes 67a engaged with the pins 65 and 66. It consists of Incidentally, the restraint means is not limited to the above-mentioned constitution, but can be constituted by a bolt and a nut or the like. Further, in the contact portion between the movable die 4 and the slide die guide 41 or the slide die 3,
Part lock 47 that can not be removed unless more force is applied
Is provided.

The movable die 4 comprises a die portion 48 having a male die 18 and a female die 17 and an ejector box 53. The ejector box 53 has a connecting portion 49 for connecting to the movable plate 10 and a metal die. An intermediate member 50 provided with a constant gap between the mold part 48 and the connection part 49, and a resin sprue runner part provided in the constant gap, in which the resin in the hollow molded product 30 and the secondary sprue 44 is solidified. And an ejector plate 52 having ejector pins 51 and 51a projecting 35. Ejector plate 5
The spring 2 is retracted by the springs 81 and 82 arranged around the ejector pins 51 and 51a when the ejecting operation is completed.

Next, the operation of the mold 1 will be described.
First, the slide cylinder 9 is extended to extend the slide die 3
To the lower position. Then, the movable platen 10 of the injection molding machine 5 is moved to the fixed platen 7 side to align the movable mold 4 and the slide mold 3, and then the slide mold 3, the runner plate 40 and the fixed mold 2 are integrated. To do. In this state,
As shown in FIG. 1, the central primary sprue 43 of the slide die 3 is continuous with the sprue 12 of the sprue bush 42, and a pair of cavities 19 and 20 are provided between the slide die 3 and the movable die 4. It is formed. Therefore, the molten resin is injected from the injection machine 11 provided on the fixed platen 7 side. Then, the molten resin passes through the sprue 12 of the sprue bush 42, the primary sprue 43 at the center of the slide die 3 and the gates 26, 26a, and then both cavities 19,
20 and fills its cavities 19, 20 as shown in FIG. In this way, in each cavity, the halved divided bodies 31, 32 of the hollow molded product are molded.

After the divided bodies 31, 32 are cooled and solidified, the movable die 4 is moved by the die opening / closing device as shown in FIG.
Also moves integrally as a result of the action of the part lock 47 and separates from the runner plate 40. When the movable die 4 further moves, the restraint means 71 acts, and the pin 45 provided on the runner plate 40 and the pin 45a provided on the slide die guide 41 on which the slide die 3 is arranged are moved by the elongated hole 46a of the pulling jig 46. , The runner plate 40 slides on the sprue bush 42 to separate from the fixed die 2, and the resin sprue runner portion 33 projects and falls from the die 1 at a predetermined position.

Next, the restraint means 72 is actuated, and the fixed mold 2
The pin 65 provided on the runner plate 40 and the pin 66 provided on the runner plate 40 engage with both ends of the elongated hole 67a of the pulling jig 67, so that the runner plate 40 is anchored to the fixed mold 2. Further, when the movable die 4 is moved in the die opening direction, the slide die guide 41 on which the slide die 3 is arranged is anchored to the runner plate 40 by the restraint means 71, and the runner plate 40 is anchored to the fixed die 2 by the restraint means 72. Therefore, the slide type guide 41 cannot move from the fixed die 2 for a certain distance or longer. Therefore, the movable die 4 is disengaged from the slide die guide 41 or the part lock 47 provided on the slide die 3, and the movable die 4 is separated from the slide die 3 as shown in FIG.
At the same time, the male molds 15 and 18 are separated from the divided bodies 31 and 32, and the divided bodies 31 and 32 are respectively formed into the female molds 17 and 16.
Remain on the side. Split bodies 31, 32 obtained in this way
Have their end faces become abutting faces 31a, 32a that are abutted against each other. Then, the butting surface 31
The protrusions 24 and 2 of the male molds 15 and 18 are provided on the periphery of a and 32a.
5, grooves 31b and 32b are formed.

Then, as shown in FIG. 5, the cylinder 9 is contracted to move the slide die 3 to the upper position. Then, the female die 16 of the slide die 3 and the female die 17 of the movable die 4 face each other, and the divided bodies 32, 31 left in the female dies 16, 17 face each other. At this time, the secondary sprue 44 below the slide die 3 faces the sprue 12 of the sprue bush 42. Therefore, in this state, the movable die 4 is moved to the fixed die 2 side to the end, and these are die-matched as shown in FIG. Then, the abutting surfaces 31a, 32a of the divided bodies 31, 32 are abutted against each other. A space formed by the grooves 31b and 32b is formed around the butted portion. This space communicates with the secondary sprue 44 via the gate 27 and the runner 21 provided on the movable die 4.

Therefore, when the molten resin is injected from the injection machine 11 in this state, the molten resin is sprue 12 of the sprue bush 42, the secondary sprue 44 below the slide die 3 and the runner 21 provided on the movable die 4. And, through the gate 27, the butted peripheral portions of the respective divided bodies 31, 32 are filled. Then, by the peripheral resin 34,
The divided bodies 31, 32 are welded to each other.

After the peripheral edge resin 34 is cooled and solidified, the movable die 4 is moved to the end in the die opening direction by the die opening / closing device as shown in FIG. 7, and the slide die 4 and the movable die 3 are separated from each other. . Next, as shown in FIG. 8, the ejector 54 is operated from the movable platen side to move the ejector pins 51 and 51a of the ejector plate 52, thereby completing the hollow molded product 30 and the resin sprue runner portion. 35 is projected from the mold 1 and falls. In this way, after taking out the hollow molded article 30,
As shown in FIG. 9, when the ejector 54 is retracted, the ejector plate 52 is also ejected by the ejector pin 5.
The springs 81, 82 arranged around the circumferences of 1, 51a move backward. Next, the cylinder 9 is extended again and the slide die 3 is positioned below. Then, the movable die 4 is moved to the fixed die 2 side to the end. Then, the state returns to that shown in FIG. In this way, the process moves to the molding process for the next molded product. (Embodiment 2) FIGS. 10 and 11 are longitudinal sectional views showing a molding die for a hollow molded article according to Embodiment 2 of the present invention. Figure 10
In the figure, a state in which the half-split bodies 31 and 32 of the hollow molded product are respectively molded is shown. Further, FIG. 11 shows a state in which the butted peripheral portions of the divided bodies 31 and 32 are filled with the peripheral edge resin 34 and the divided bodies 31 and 32 are welded to each other to form the hollow molded article 30. Has been done.

That is, the method for molding the hollow molded article is as follows:
As shown in FIG. 10, a movable mold 104, which is one of the molds, is divided into two hollow molded products, which are divided bodies 31 and 32.
A male die 15 and a female die 16 for respectively molding
A fixed die 102, which is the other die, is provided with a female die 17 and a male die 18 that face the male die 15 and the female die 16, respectively. Molten resin is injected into a pair of cavities 19 and 20 formed between the molds 15 and 18 and the female molds 17 and 16 to mold the divided bodies 31 and 32, and then, as shown in FIG. As described above, the movable mold 104 is separated from the fixed mold 102, and the movable mold 104, which is one mold, is slid,
After the respective divided bodies 31, 32 left in the respective female dies 17, 16 are opposed to each other and the respective dies 102, 104 are matched with each other, the respective divided bodies 31, 32 are butted against each other, and then the butting surface thereof is obtained. Molten resin is injected to the peripheral edges of 31a and 32a, and each divided body 3 is injected by the peripheral edge resin 34.
1 and 32 are configured to be welded to each other.

The mold for molding the hollow molded product is shown in FIG.
As shown in FIG. 3, the fixed mold 102 having a single sprue 12 and the movable mold that moves between two positions along a guide plate 105 attached to the movable plate 10 and is matched with the fixed mold 102. It consists of 104.

The movable die 104 comprises a die portion 48 having a male die 15 and a female die 16 and an ejector box 53, and the ejector box 53 slides along a guide plate 105 attached to the movable platen 10. Connection 49
And an intermediate member 50 that provides a fixed gap between the mold part 48 and the connection part 49, an ejector plate 152 that has the ejector pins 151 and 151a that are provided in this constant gap, and an ejector that has the ejector pin 153. It is composed of a plate 154. The ejector plates 152 and 154 have the ejector pin 15
Springs 84, 8 arranged around 1, 151a, 153
When the eject operation is completed by 5,83, the vehicle moves backward.

On the upper surface of the guide plate 105, a frame 8 having a horizontal arm 8a is erected. A slide cylinder 9 operated by hydraulic pressure or pneumatic pressure is attached to the lower surface of the horizontal arm 8a. An electric motor may be used instead of this cylinder. The piston rod 9a of the cylinder 9 is a movable mold 1
It is connected to the upper surface of 04. Thus, the movable mold 104
Keeps in close contact with the surface of the guide plate 105,
The cylinder 9 is slid up and down between the most extended position and the most retracted upper position.

The movable die 104 is attached via a guide plate 105 to a movable platen 10 supported horizontally on a bed of an injection molding machine (not shown). This movable plate 1
04 is moved back and forth with respect to the fixed platen 7 by a mold opening / closing device (not shown). In this way, the movable mold 104 is moved back and forth between the mold matching position in which the movable mold 104 is in close contact with the fixed mold 102 and the mold open position separated from the fixed mold 102.

The movable mold 104 has a male mold 15 for molding divided bodies 31, 32 obtained by dividing a hollow molded product into two parts.
And a female die 16, and runners 21a and 21b continuous with the sprue 12 of the fixed die 102 at the two positions are provided.
Is provided with a female die 17 and a male die 18, which face the male die 15 and the female die 16, respectively, when the movable die 104 is at one position (see FIG. 10), and the female die 17 is
When the movable die 104 moves to the other position (see FIG. 11), it faces the female die 16 of the movable die 104, and the runner 21a is continuous with the sprue 12 of the fixed die 102. When in the state (see FIG. 10), the gates 23, 22 are attached to the edge portions of these female molds 16, 17.
When the runner 21b is continuous with the sprue 12 (see FIG. 11), the end portions of the female molds 16 and 17 are communicated with each other through the gate 27. Has been done.

Further, the male dies 15 and 18 are provided with projections 24 and 25 for forming grooves 31b and 32b on the peripheral edges of the abutting surfaces 31a and 32a of the divided bodies 31 and 32, respectively.

Further, as shown in FIG. 10, in the fixed gap provided in the ejector box 53 of the movable die 104, molten resin is filled in the cavities 19 and 20 for molding the divided bodies 31 and 32, respectively. Ejector pin 1 for sticking out resin sprue runner part 33 filled with
As shown in FIG. 11, the ejector plate 154 having 53 and the resin sprue runner portion 3 in which the peripheral edge resin 34 is filled in the abutting peripheral edge portions of the respective divided bodies 31, 32.
Ejector plate 152 having ejector pins 151 and 151a for ejecting hollow molded product 30 formed by welding 5 and divided bodies 31, 32 to each other
Are provided. The ejector plate 15
2, 154 are ejectors 54 provided on the movable platen 10 side.
Works by.

Next, the operation of the mold 1 will be described. After the divided bodies 31 and 32 are formed as shown in FIG. 10, the movable mold 104 is fixed to the fixed mold 10 by a mold opening / closing device.
Separate from 2. When opening this mold, sprue 1 of mold 1
2 and the resin sprue runner portion 33 solidified in the runner 21a and the like are ejected from the mold 1 by the ejector plate 154 having the ejector pin 153, and are separated at the portions corresponding to the gates 22 and 23 and fall. After the drop, when the ejector 54 is retracted, the ejector plate 154 also retracts by the action of the spring 83 arranged around the ejector pin 153.

Further, as shown in FIG. 11, after the divided bodies 31, 32 are welded to each other by the peripheral resin 34,
Again, the movable mold 104 is moved to the fixed mold 102 by the mold opening / closing device.
Away from.

When the mold is opened, the hollow molded product 30 completed
The resin sprue runner portion 35 solidified in the mold sprue 12 and the runner 21b is the ejector pin 1 described above.
The ejector plate 152 having 51 and 151a projects from the mold 1 and drops. In this way, after ejecting the hollow molded article 30, the ejector 54
When retracted, the ejector plate 152 also moves the spring 8 arranged around the ejector pins 151 and 151a.
It retreats by the action of 4,85. (Embodiment 3) FIGS. 12 and 13 are longitudinal sectional views showing a molding die for a hollow molded article according to Embodiment 3 of the present invention. 12
In the figure, a state in which the half-split bodies 31 and 32 of the hollow molded product are respectively molded is shown. Further, FIG. 13 shows a state in which the butted peripheral portions of the divided bodies 31, 32 are filled with the peripheral resin 34 and the divided bodies 31, 32 are welded to each other to form a hollow molded article. ing.

That is, the molding die of the hollow molded article of this example is almost the same as the conventional example except for the following constitution. That is, the movable mold 4 is composed of a mold part 48 having a male mold 18 and a female mold 17, and an ejector box 53. The ejector box 53 is connected to the movable platen 10 and a mold part 48. 1 and an intermediate member 50 that provides a constant gap between the connection portion 49 and the connection portion 49.
As shown in FIG. 2, the sprue 12 and the runner 21a are provided in the cavities 19 and 20 to mold the divided bodies 31 and 32, respectively.
13, the sprue runner portion 33 formed by filling the molten resin through the gates 22 and 23, and the sprue 12, the runner 21b, and the slide type gate 27 provided at the abutting peripheral edge portions of the divided bodies 31 and 32 as shown in FIG. Resin sprue runner portion 35 formed by filling the peripheral portion resin 34 through
A cylinder 60 for ejecting and from the mold, and a cylinder 61 for ejecting from the mold 1 a hollow molded product 30 formed by welding the divided bodies 31 and 34 to each other as shown in FIG. The cylinders 61 and 62 are operated by hydraulic pressure or pneumatic pressure. An electric motor may be used instead of this cylinder.

Next, the operation of the mold 1 will be described. After forming the divided bodies 31 and 32 as shown in FIG. 12, the movable die 4 is separated from the slide die 3 by a die opening / closing device. At the time of opening the mold, the resin sprue runner portion 33 solidified in the sprue 12 and the runner 21a of the mold 1
Are ejected from the mold 1 by the cylinder 60, separated at the portions corresponding to the gates 22 and 23, and fall.

Further, as shown in FIG. 13, after the divided bodies 31, 32 are welded to each other by the peripheral resin 34,
The movable mold 4 is separated from the slide mold 3 again by the mold opening / closing device.

When this mold is opened, the hollow molded product 30 completed
Is ejected from the mold by the ejecting cylinder 61 and the resin sprue runner portion 35 is ejected from the mold by the ejecting cylinder 60 and falls.

In the first and second embodiments described above, the selection switch is used to select whether or not the resin sprue runner portion 33, in which each cavity is filled with the molten resin, is projected by the single ejector 54. Has been

[0061]

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

In the method for molding a hollow molded article and the mold used therefor, the runner plate and the ejector plate are used in combination, so that a single ejector only needs to be operated once. Further, since molten resin is injected from the primary sprue provided in the slide mold to mold the divided body, the size of the gate can be optimized according to various molded products. Further, after the respective divided bodies are butted against each other, the molten resin is injected from the secondary sprue provided on the peripheral edge of the butted surface to the die through the runner and the gate provided on the movable die,
The size of the gate can be optimized as described above.

In the method of molding a hollow molded article and the mold used therefor, two sets of ejector plates are used, and any ejector plate can be operated by a single ejector. Also, after the divided bodies are butted against each other, the molten resin is injected into the die through the runner and gate provided in the movable die at the periphery of the butted surface, but the size of the gate should be the same as above. You can

Further, since the movable mold is attached to the movable platen, it is excellent in maintenance and operation of the mold.

In the mold for molding the hollow molded product according to the thirteenth aspect, since two sets of cylinders are used, it is not necessary to use an ejector. Further, after the respective divided bodies are butted against each other, the molten resin is injected into the die through a runner and a gate provided on the movable die at the periphery of the butted surface, and the dimensions of the gate are also optimum as described above. be able to.

In the mold for molding a hollow molded article according to the fourteenth aspect, the selection switch for selecting whether or not the resin sprue runner portion in which each cavity is filled with the molten resin is projected by a single ejector. Therefore, by switching the selection switch, it is possible to use the mold of the first or second embodiment, for example.

As described above, both the method according to the present invention and the mold used therefor can be applied to an injection molding machine having a single ejector, and a mold according to the type of hollow molded product is adopted. Will be possible.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a molding die for a hollow molded product according to a first embodiment.

FIG. 2 is a vertical cross-sectional view showing a molding process of a hollow molded product according to the first embodiment.

FIG. 3 is a vertical cross-sectional view showing a molding process of a hollow molded product according to the first embodiment.

FIG. 4 is a vertical cross-sectional view showing a molding process of a hollow molded product according to the first embodiment.

FIG. 5 is a vertical cross-sectional view showing a molding process of a hollow molded product according to the first embodiment.

FIG. 6 is a vertical cross-sectional view showing a molding process of a hollow molded product according to the first embodiment.

FIG. 7 is a vertical cross-sectional view of a molding die for a hollow molded product according to the first embodiment.

FIG. 8 is a vertical cross-sectional view showing the molding process of the hollow molded product according to the first embodiment.

FIG. 9 is a vertical cross-sectional view showing a molding process of a hollow molded product according to the first embodiment.

FIG. 10 is a vertical cross-sectional view of a molding die for a hollow molded product according to the second embodiment.

FIG. 11 is a vertical cross-sectional view showing a molding process of a hollow molded product according to the second embodiment.

FIG. 12 is a vertical cross-sectional view of a molding die for a hollow molded article according to the third embodiment.

FIG. 13 is a vertical cross-sectional view showing a molding process of a hollow molded product according to the third embodiment.

FIG. 14 is a vertical cross-sectional view of a molding die for a hollow molded article according to a conventional example.

FIG. 15 is a vertical sectional view showing a molding process of a hollow molded article according to a conventional example.

[Explanation of symbols]

 1 Mold 2 Fixed Type 3 Slide Type 4 Movable Type 5 Injection Molding Machine 9 Sliding Cylinder 11 Injection Machine 12 Sprue 13, 14 Sub Sprue 15 Male Mold 16, 17 Female Mold 18 Male Mold 19, 20 Cavity 21 Runner 22, 23 Gate 24, 25 Protrusion 30 Hollow molded product 31, 32 Divided body 31a, 32a Butt face 31b, 32b Groove 33, 35 Resin sprue runner part 34 Peripheral resin 40 Runner plate 41 Sliding type guide 43 Primary sprue 44 Secondary sprue 46 Pull Jig 48 Mold part 49 Connection part 50 Intermediate part 51, 151, 153 Ejector pin 52, 152, 154 Ejector plate 53 Ejector box 54 Ejector 60, 61 Cylinder 71, 72 Restraint means 102 Fixed type 104 Movable type 105 Moth De plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display area B29L 22:00

Claims (14)

[Claims] 1. A male mold (18) for molding a divided body (31, 32) obtained by dividing a hollow molded product (30) into two parts, into a movable mold (4) which is one mold attached to a movable plate (10). ) And a female die (17) are provided, and the male die is attached to the other die, the slide die (3), which is disposed in a horizontally moving slide die guide (41) and moves between two positions. (18) and female mold (17) are provided with a female mold (16) and a male mold (15), respectively, and a pair of molds is used. Female (1
7, 16) and a pair of cavities (1
The molten resin is injected into the inside of 9, 20) from the primary sprue (43) provided in the slide mold (3), and each divided body (31,
32) and then the movable die (4) is provided between the fixed die (2) and the slide die (3) together with the slide die guide (41) in which the slide die (3) is arranged ( 40), then the resin sprue runner part (33) solidified in the primary sprue (43) is projected from the mold (1), and the movable mold (4) and the slide mold (3) are arranged. After separating from the slide type guide (41), the slide type (3) is slid to form each female type (17, 16).
After the respective divided bodies (31, 32) are made to face each other by making the respective divided bodies (31, 32) face each other and the respective molds (3, 4) are matched, Molten resin is injected from the secondary sprue (44) provided on the slide mold (3) around the periphery of (31a, 32a), and the divided bodies (31, 32) are welded to each other by the peripheral resin (34). Method for forming a hollow molded article. 2. A runner plate (40) provided between the fixed die (2) and the slide die (3) is separated from the fixed die (2) and solidified in the primary sprue (43). The method for molding a hollow molded article according to claim 1, wherein the resin sprue runner portion (33) is projected from the mold. 3. A resin sprue solidified in the secondary sprue (44) by ejecting an ejector plate (52) provided on the movable platen (10) side of the movable die (4) with a single ejector (54). Runner (35) and hollow molded product (3
The method for molding a hollow molded article according to claim 1 or 2, wherein 0) is projected from the mold. 4. A stationary mold (2) having a single sprue.
And a slide type guide (41) that moves in the horizontal direction,
A slide die (3) that moves between two positions in the slide die guide (41), and a movable die (4) that is fitted to the slide die (3).
And a runner plate (40) provided between the fixed mold (2) and the slide mold (3) and moving in the horizontal direction. The hollow mold product (30) is divided into two parts in the slide mold (3). A male mold (15) and a female mold (16) for respectively molding the divided bodies (31, 32) are provided, and
In the two positions, the sprue (1) of the fixed type (2)
2) is provided with a primary sprue (43) and a secondary sprue (44) which are continuous with each other, and the movable die (4) has its male part when the slide die (3) is in one position. A female mold (17) and a male mold (18) respectively facing the mold (15) and the female mold (16) are provided to form a pair of cavities (19, 20), and the female mold (17) is Female mold (16) of the slide mold (3) when the slide mold (3) moves to the other position
When the primary sprue (43) is continuous with the sprue (12) of the fixed mold (2), the primary sprue (43) communicates with the pair of cavities (19, 20). And the secondary sprue (44) is the sprue (1) of the fixed type (2).
2), it is arranged so as to communicate with the end edge of the female mold (16, 17), and each of the male molds (15, 18) has the divided body (31, 3).
2) Grooves (3) are formed on the periphery of each butting surface (31a, 32a).
Mold for molding a hollow body provided with projections (24, 25) for molding 1b, 32b). 5. A mold for molding a hollow body according to claim 4, further comprising restraint means (71) for restraining the slide type guide (41) having the slide type (3) arranged on the runner plate (40). . 6. The restraining means (71) includes pins (45, 45a) provided in the same horizontal direction on a runner plate (40) and a slide type guide (41) on which a slide type (3) is arranged, respectively. The mold for molding a hollow molded article according to claim 5, comprising a drawing jig (46) having an elongated hole (46a) engaged with the pin (45, 45a). 7. The mold for molding a hollow molded product according to claim 4, 5 or 6, further comprising restraint means (72) for restraining the runner plate (40) to the fixed die (2). 8. Pins (65, 66) provided with restraining means (72) respectively in the same horizontal direction of the fixed mold (2) and the runner plate (40), and the pins (65, 6).
6) A pulling jig (6) having an elongated hole (67a) engaged with
7) The mold for molding a hollow molded article according to claim 7. 9. The movable mold (4) comprises a mold part (48) having a male mold (18) and a female mold (17), and an ejector box (53).
3) is a connection part (4) attached to the movable plate (10).
9), an intermediate member (50) provided with a constant gap between the mold part (48) and the connection part (49), and an ejector plate (52) provided in this gap. 52) is each divided body (31, 32)
A resin sprue runner portion (35) obtained by filling a peripheral edge resin with a peripheral edge resin (34) and each divided body (31, 3).
Hollow molded article (30) formed by welding 2) to each other
And ejector pin (51,51
Mold according to any one of claims 4 to 8, having a), wherein the ejector plate (52) is actuated by a single ejector (54). 10. A hollow mold product (30) is divided into two parts into a movable mold (104) which is one mold which moves between two positions along a guide plate (105) attached to the movable plate (10). A male die (15) and a female die (16) for respectively forming the bodies (31, 32) are provided, and a fixed die (102) which is the other die attached to the fixed board (7),
A pair of metal molds provided with a female mold (17) and a male mold (18) respectively facing the male mold (15) and the female mold (16) are used, and the male molds (15, 18) and female (1
7 and 16) and a pair of cavities (1
Molten resin is injected into each divided body (31, 3).
2), then the movable mold (104) is separated from the fixed mold (102), and a resin sprue runner part (33) formed by filling a pair of cavities (19, 20) with molten resin is formed from the mold. Each divided body (31, 32) left in each female mold (16, 17) by protruding and then sliding the movable mold (104)
By facing each other and aligning the molds (102, 104),
After the respective divided bodies (31, 32) are butted against each other, a molten resin is injected to the peripheral edge of the butted surface so that the circumferentially divided resin (34) welds the respective divided bodies (31, 32) together. Molding method for hollow molded article. 11. A fixed mold (102) mounted on a fixed plate (7) and having a single sprue, and a movable plate (1).
0) attached to the fixed mold (102) and moved between two positions along a guide plate (105) attached to the movable mold (104), wherein the movable mold (104) is hollow. A male mold (15) and a female mold (16) for molding divided bodies (31, 32) obtained by dividing a molded product (30) into two are respectively provided, and the sprue () of the fixed mold (102) is provided at the two positions. 1
2) continuous runners (21a, 21b) are provided, and the fixed mold (102) has its male mold (15) and female mold (15) when the movable mold (104) is in one position. 1
6) is provided with a female die (17) and a male die (18) respectively facing each other, and the female die (17) has the movable die (10).
4) when the movable type (10) moves to the other position.
4) facing the female mold (16), and when the sprue (12) continues to the runners (21a, 21b) of the movable mold (104), these female molds (1)
6 and 17) so as to communicate with the edge portions of the divided bodies (31, 3).
2) Grooves (3) are formed on the periphery of each butting surface (31a, 32a).
1b, 32b) molding die for hollow molding provided with projections (24, 25). 12. The movable mold (104) is a male mold (1).
5), a mold part (48) having a female mold (16), and an ejector box (53), the ejector box (53) extending along a guide plate (105) attached to the movable platen (10). A sliding connection part (49), an intermediate member (50) that provides a fixed gap between the mold part (48) and the connection part (49), and an ejector plate (152, 154) provided in this gap. The ejector plate (152, 154) is composed of
Each cavity (19, 2) to mold
Ejector pin (15) that projects the resin sprue runner part (33) formed by filling molten resin into the mold
3) Ejector plate (154) and resin sprue runner portion (35) formed by filling the peripheral resin (34) at the abutting peripheral edge of each divided body (31, 32)
And an ejector plate (152) having ejector pins (151a, 151) for ejecting a hollow molded article (30) formed by welding the divided bodies (31, 32) to each other. 1
Mold for molding a hollow molded article according to claim 11, wherein 54, 152) are operated by a single ejector (54). 13. A fixed mold (2) having a single sprue (12), a slide mold (3) moved between two positions along the fixed mold (2), and a mold for the slide mold 3. A movable mold (4) to be combined with each other, and a male mold (15) and a female mold for molding split bodies (31, 32) into which the hollow molded product (30) is divided into two, respectively, in the slide mold (3). (16) and are provided,
In the two positions, the sprue (1) of the fixed type (2)
2) continuous sub-sprues (13, 14) are provided, and the movable mold (4) has its male mold (15) and female mold (16) when the slide mold 3 is at one position. Are provided with a female mold (17) and a male mold (18), which face each other, and when the female mold (17) moves to the other position of the slide mold (3), The sub-sprue (13, 14) is adapted to face the female mold (16), and the fixed mold (2)
When the sprue (12) is continuous with the female molds (16, 17), the male molds (15, 18) are connected to the divided bodies (31). , 3
2) Grooves (3) are formed on the periphery of each butting surface (31a, 32a).
1b, 32b) are provided with protrusions (24, 25), and the movable mold (4) has a mold part (48) having a male mold (18) and a female mold (17) and an ejector box (53). ) And the ejector box (53) is a movable plate (10).
An intermediate member (5) that provides a fixed gap between the connection part (49) for connecting with the mold part (48) and the connection part (49).
0) and cylinders (60, 61) provided in this gap
And the cylinders (60, 61) are provided with respective cavities (19, 19) for molding the respective divided bodies (31, 32).
20) a resin sprue runner part (33) filled with a molten resin, and a resin sprue runner part (35) formed by filling a peripheral edge resin (34) in a butting peripheral part of each divided body (31, 32). Cylinder (60) that ejects from the mold
And a hollow molded article (3) formed by filling the peripheral resin (34) into the butted peripheral portions of the respective divided bodies (31, 32).
A mold for forming a hollow body, which comprises a cylinder (61) for projecting 0) from the mold. 14. A selection switch is used to select whether or not the resin sprue runner portion (33) formed by filling each cavity (19, 20) with molten resin is projected by a single ejector (54). A mold for molding a hollow molded article according to claim 9 or 12.