JPH0970855A - Molding of hollow molded products of different kind - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce molding cost by using a general-purpose molding machine by respectively molding a different kind of split members and allowing one of them to be opposed to the other one of them to perform mold clamping and fusing the synthetic resin from a first or second injection device to the abutted part of them to mold a hollow molded product. SOLUTION: First and second molds 9, 12 are clamped to inject the first synthetic resin from a first injection device 23 into the center of the first molding space 33 formed by one core 9b and a cavity 21b and a second resin different from the first synthetic resin is injected into the second molding space 31 formed by other core 9a and a cavity 21a from the second injection device positioned on the lateral side of a molding machine by a parting injection method to form respective split members 13b, 13a. Next, the first mold 9 is moved to opposed the split member 13b in a cavity 9b to the split member 13a held in the cavity 21a of a second mold 21 to perform mold clamping and a synthetic resin is fused to the abutted part of the split members 13a, 13b from the first or second injection devices 23 to mold a hollow molded product.

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 heterogeneous hollow molded article in which divided bodies each having a concave portion and molded with different synthetic resins are integrated so as to have a hollow portion inside.

[0002]

For example, in the case of a float valve that is installed in a flush tank that stores water discharged to a flush toilet and that discharges water or stops water, it moves up and down in the tank. Since it is necessary to attach a guide shaft that supports to the above or a hinge that supports to rotate, it is necessary to form the mounting part with a hard synthetic resin having a certain degree of hardness, while it is necessary to ensure water stop, the valve seat It is necessary to form a soft synthetic resin having elasticity in the portion in close contact with.

A conventional float valve is formed of a single synthetic resin by a blow molding method, although the above-mentioned contradictory functions are required. For this reason, only one of the above-mentioned contradictory functions can be achieved, resulting in poor durability and poor waterproofness.

Further, after using two molding machines to mold the divided bodies of different kinds of hollow moldings with different synthetic resins, the synthetic resin is fused to the abutting portions of these divided bodies to form hollow portions inside. It is possible to mold different kinds of hollow molded products having the following, but since this molding method requires two molding machines, the equipment cost becomes high and the divided bodies molded by each molding machine are separated from each other. Since the work for butting and the work for joining are required, there is a problem that the number of working steps increases and the molding cost increases.

The above-mentioned drawback is that two injection devices for injecting different synthetic resins are attached to the molding machine, and the divided bodies are simultaneously molded with the synthetic resins injected from the respective injection devices, and then one of the molds is moved. A hollow molded product can be molded by fusing synthetic resin to the abutting parts of the divided bodies that are abutted with each other, but it is impossible to mold with existing molding machines and a dedicated molding machine is required. There has been a problem that the cost becomes high and the molding cost cannot be reduced.

An object of the present invention is to provide a method for molding a heterogeneous hollow molded article which can efficiently join the divided bodies made of different kinds of synthetic resins to each other to satisfy the contradictory functions and reduce the molding cost. It is in.

Another object of the present invention is to provide a method for molding a heterogeneous hollow molded article which can reduce the molding cost by using a general-purpose molding machine.

[0008]

Therefore, according to the present invention, the core and the other divided body corresponding to one divided body constituting the hollow molded article are attached to the first mold movably mounted on the fixed side. It has a cavity that matches with the second movable side.
A mold and a cavity and a core facing the cavity of the first mold are provided in the mold, and the first and second molds are clamped with respect to the first molding space composed of the core and the cavity. From the first injection device attached to the fixed side, the first synthetic resin is centrally injected, and from the second injection device arranged on the side of the molding machine with respect to the second molding space formed of the other core and the cavity. A second synthetic resin different from the first synthetic resin is parting-injected to mold different kinds of divided bodies.

Next, after the first die is moved and one division body held in the cavity is made to face the other division body held in the cavity of the second die, the die is clamped. First or second with respect to the abutting portion of each divided body
A synthetic resin injected from an injection device is fused to form a hollow molded article of a different type having a hollow portion inside.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a central vertical cross-sectional view of a die mounting portion.

FIG. 2 is an overall perspective view showing an example of a molding machine which embodies the method for molding a different type hollow molded product.

FIG. 3 is a cross-sectional view of the die mounting portion according to the parting injection position.

First, the molding machine will be described. A support frame 5 extending vertically is fixed to a fixed side mounting board 4 of a main body frame 3 of the molding machine 1, and a movable board 7 supported by the support frame 5. A first mold 9 is detachably attached to the. A vertical drive member 11 attached to the support frame 5 is connected to the movable plate 7, and the movable plate 7 is moved between an upper position and a lower position by driving the vertical drive member 11. The vertical drive member 11 shown in the figure shows the case where a cylinder is used, but it is axially supported by the support frame 5, rotated forward and backward by an electric motor, and meshed with a nut portion (neither shown) of the movable platen 7. You may comprise with a screw shaft.

Further, in the first mold 9, a core 9a having a shape matching the inner shape of one of the divided bodies 13a constituting the hollow molded product 13 is provided on the upper side, and a cavity 9b having a shape matching the outer shape of the other divided body 13b. Are formed at the bottom, respectively. The reference numeral 9c in the drawing is a sprue that communicates with the cavity 9b,
When the movable plate 7 is moved downward, the sprue 9c is provided with the fixed side mounting plate 4, the support frame 5, and the through hole 4a of the movable plate 7.
-It is formed so as to match 5a and 7a, respectively.

The movable side mounting board 1 is attached to the tie bar 15 which is horizontally mounted between the main body frame 3 of the molding machine 1 and the fixed side mounting board 4.
7 is supported so as to slide in the axial direction, and the movable side mounting board 17 is a mold clamping member 19 mounted on the main body frame 3.
Is moved between the mold closing position and the mold opening position. The mold clamping member 19 is composed of a cylinder.

Movable side mounting board 1 facing fixed side mounting board 4
A second mold 21 is removably attached to 7, and a cavity 21a facing the core 9a in conformity with the outer shape of one of the divided bodies 13a is provided on the upper part of the second mold 21, and a lower part is provided on the lower part. Cores 21b are formed to match the inner shape of the other divided body 13b and face the cavities 9b. still,
Reference numeral 21c in the drawing is a sprue which is provided on the parting surface of the second mold 21 and communicates with the cavity 21a.

Further, a protrusion (not shown) is provided on one or both of the core 9a of the first die 9 and the core 21b of the second die 21 on the outer peripheral side of the abutting surface of the divided bodies 13a and 13b. It is possible to provide a recessed portion that is filled with a synthetic resin for joining to the outer periphery of the butted portion when the divided bodies 13a and 13b are butted with each other.

A first injection device 23 is attached to the body frame 3 on the fixed side mounting plate 4 side, and an injection nozzle 23a of the first injection device 23 can be aligned with the sprue 9c. To be separated from.

A sub-frame 25 is arranged on the side of the main body frame 3, and a second injection device 27 is attached to the sub-frame 25. The second injection device 27 brings the injection nozzle 27a into contact with and separates from the sprue 21c on the mold matching surfaces of the first mold 9 and the second mold 21 that have been clamped.

As the first synthetic resin injected from the first injection device 23, ABS resin, vinyl chloride resin,
A hard synthetic resin having hardness when cured, such as polypropylene resin, or a second synthetic resin injected from the second injection device 27 has elasticity when cured and has a higher melting temperature than the second synthetic resin. Any elastomer resin may be used.

Next, a molding method using the above apparatus example will be described.

FIG. 4 is a vertical sectional view showing a molding state of each divided body.

FIG. 5 is a cross-sectional view taken along the line VV in FIG.

FIG. 6 is a vertical sectional view showing a state in which the divided bodies are joined to each other.

FIG. 7 is a transverse sectional view taken along the line VII-VII in FIG.

FIG. 8 is an enlarged sectional view of the hollow molded product.

The vertical drive member 11 is driven to move the movable platen 7 downward to move the first mold 9 to the second mold 21, the core 9a and the cavity 21a, and the cavity 9b.
And the core 21b are made to face each other so as to coincide with each other, and then the mold clamping member 19 is operated to clamp the second mold 21 to the first mold 9. At this time, the core 9a and the cavity 21a
And a second molding space 33 is formed between the cavity 9b and the core 21b.

As shown in FIGS. 4 and 5, in the above state, the first injection device 23 through the through hole 4 is inserted into the second molding space 33.
a. 5a and the sprue 9c to inject the first synthetic resin, and the second injection device 27 to the first molding space 31 to inject the second synthetic resin via the sprue 21c, respectively.
3a and 13b are simultaneously molded. The other divided body 13b becomes hard when it is hardened, and the other divided body 13b
a has elasticity.

Next, after the divided bodies 13a and 13b are molded and cured, the mold clamping member 19 is returned to move from the first mold 9 to the second mold 2.
After the mold 1 is released, the sprues of the divided bodies 13a and 13b are separated and discharged. At this time, one divided body 13a is held in the cavity 21a, and the other divided body 13b is held in the cavity 9b.

Next, the vertical drive member 11 is driven in the opposite direction to move the movable platen 7 upward, and the first die 9 is held in the cavity 9b with respect to the second die 21. Divided body 1 held in divided body 13a and cavity 21a
3b and 3b, the mold clamping member 19
Is operated to clamp the second mold 21 to the first mold 9.
At this time, the abutting surfaces of the divided bodies 13a and 13b are in contact with each other so as to provide a hollow portion 13c therein.

Next, as shown in FIGS. 6 and 7, in the above state, the parting injection is performed from the second injection device 27 through the sprue 21c on the die matching surface between the first die 9 and the second die 21. The joint portion 13d of the second synthetic resin to be melted is fused to the abutting portion of the divided bodies 13a and 13b to form the hollow portion 13 inside.
A hollow molded product 13 having c is molded.

As a result, the existing molding machine is provided with the moving structure of the first mold 9 and the second injection device 27 is added, so that the hollow molded product 13 is divided into the divided bodies 13a and 13b.
Hollow molded product 1 by simultaneously molding
3 can be molded, and the molding cost can be reduced by avoiding an increase in the equipment cost of the molding machine. Also, each divided body 1
3a and 13b can be molded with different kinds of synthetic resins,
The hollow molded product 13 can also have different functions due to the respective synthetic resins.

In the above description, the movable platen 7 is supported by the support frame 5 of the fixed side mounting plate 4 so as to be movable in the vertical direction, and the first mold 9 is attached to the cavity 21a and the core 21b of the second mold 21. Although the cores 9a and the cavities 9b are selectively opposed to each other to simultaneously form the divided bodies 31a and 13b and the two are fused together, the fixed side mounting board 4 is horizontally aligned as shown in FIGS. 9 and 10. The movable platen 53 is movably supported in the horizontal direction on the support frame 51 attached so as to extend to the core 55a of the first die 55 attached to the movable platen 53 by the horizontal movement of the movable plate 53 and Cavity 55b and second mold 57 cavity 57a
And the core 57b are selectively opposed to each other and the divided body 13a.
13b is simultaneously molded by the center injection by the first injection device 23 and the parting injection by the second injection device 27, and the cavity 55b of the first mold 55 holding the divided body 13b and the second mold holding the divided body 13a. The first injection device 2 after the cavities 57a of 57 are made to face each other.
The second synthetic resin that is center-injected from
The hollow molded product 13 may be molded by fusion bonding with a and 13b.

In the above description, the split body 13a is formed by the synthetic resin parting-injected from the second injection device 27, and the split body 13b is formed by the synthetic resin center-injected by the first injection device 23, and then the split body 13b is divided. Body 13a-1
A synthetic resin that is parting-injected from the second injection device 27 is fused to the abutting portion of 3b to form a hollow molded product having a hollow portion inside.
After a is molded with a synthetic resin that is center-injected from the first injection device 23 and a divided body 13b is formed with a synthetic resin that is part-injected from the second injection device 27, the divided body 13 is formed.
The first injection device 23 for the a / 13b abutting portion
Alternatively, a method of forming a hollow molded article by fusing with a synthetic resin that is center-injected from

That is, the injection method for molding the other divided body 13b formed of the first synthetic resin and the one divided body 13a formed of the second synthetic resin is such that the divided bodies 13a and 13b are joined together. In addition, any of the center injection type and the parting injection type may be used as long as the resin having a melting temperature higher than the melting temperature of the other resin is injected.

In the above description, the first mold 9 on the fixed side is moved vertically or horizontally to form the hollow molded product 13, but the fixed mold is fixedly mounted and movable. A method of forming a hollow molded product by mounting a mold on the board side so as to move vertically or horizontally and simultaneously molding each divided body made of different kinds of synthetic resin and then fusing the divided bodies with each other by resin. It may be.

[0037]

EXAMPLES Next, a method of forming a float valve attached to a flush tank will be described.

FIG. 11 is an overall perspective view of the float valve.

FIG. 12 is a vertical sectional view taken along the line XII-XII in FIG.

FIG. 13 is a vertical cross-sectional view of a mold showing a molding state of each divided body of the float valve.

FIG. 14 is a cross-sectional view taken along the line XIV-XIV in FIG.

FIG. 15 is a vertical cross-sectional view of a die showing a joined state of each divided body.

FIG. 16 is a cross sectional view taken along the line XVI-XVI in FIG.

The float valve 71 as a different type hollow molded product has a hemispherical shape and an upper divided body 71a formed of a hard synthetic resin and a lower divided body 71b formed of an elastic synthetic resin (elastomer resin) similarly to the upper divided body 71a. The joint 7
It has a structure joined by 1e, and a through hole 71c is formed in the lower end portion of the lower divided body 71b. A guide shaft 71d is integrally formed on the inner surface of the top of the upper divided body 71a so as to extend in the radial direction and project outward from the through hole 71c. The guide shaft 71d is supported by a shaft support hole (not shown) provided in a valve seat (not shown) that supports the float valve 71, and prevents the float valve 71 from coming off from the valve seat.

The float valve 71 is molded as follows.

The first mold 73 supported so as to be movable in the vertical direction or the horizontal direction has a core 73a which substantially matches the inner surface shape of the lower divided body 71b and a cavity 73b which substantially matches the outer surface shape of the upper divided body 71a. Are formed at required intervals in the vertical direction or the horizontal direction.

A second mold 75, which is mounted immovably relative to the first mold 73, has a projection 75a which substantially matches the outer surface shape of the lower divided body 71b and forms a through hole 71c. Hole 7 for inserting the guide shaft 71d at the center of the protrusion 75a
Cavity 75c with 5b formed on core 73a,
Moreover, the shape of the guide shaft 7
A core 75e having a hole 75d corresponding to 1d is formed to face the cavity 73b.

Then, the second die 75 is clamped to the first die 73 so that the core 73a and the cavity 75c face each other and the cavity 73b and the core 75e face each other, and then the second die 75 is formed by the cavity 73b and the core 75e. The first injection device 77 centrally injects the hard synthetic resin into the formed molding space, and the second injection device 7 is formed in the molding space formed by the core 73a and the cavity 75c.
The elastomer resin is parting-injected by 9 to simultaneously mold the upper divided body 71a and the lower divided body 71b. A hole 75d is formed in the upper divided body 71a thus formed.
Thus, the guide shaft 71d is integrally molded, and the through hole 71c is formed in the lower divided body 71b by the protrusion 75a.

Next, the first die 73 to the second die 75
After the mold is opened, the first mold 73 is moved upward or in the horizontal direction to hold the upper split body 71a.
Cavity 75c holding 3b and lower divided body 71b
Then, the first mold 73 is clamped to the second mold 75. At this time, the guide shaft 71d of the upper divided body 71a held by the cavity 73b is inserted into the hole 75b and the divided surfaces of the upper divided body 71a and the lower divided body 71b are butted against each other.

Next, in the above state, the second injection device 79
When the elastomer resin is parting-injected from the elastomer resin, the elastomer resin is injected into the upper divided body 71a and the lower divided body 71b.
The float valve 71 is formed by fusion bonding and joining to the outer peripheral surfaces of the abutting points in FIG.

In the above description, the guide shaft 71 is attached to the upper divided body 71a.
Although d is integrally formed of the same synthetic resin, the guide shaft is a metal shaft member, and when the upper divided body 71a is formed, the guide shaft is attached to the hole 75d.
It may be a method of integrally molding with a.

[0052]

Therefore, according to the present invention, in order to satisfy the contradictory functions, the divided bodies made of different synthetic resins can be efficiently joined to each other to reduce the molding cost.
Further, the present invention can reduce the molding cost by using a general-purpose molding machine.

[Brief description of drawings]

FIG. 1 is a central vertical cross-sectional view of a mold mounting portion.

FIG. 2 is an overall perspective view showing an example of a molding machine that embodies a method for molding a different type hollow molded product.

FIG. 3 is a transverse cross-sectional view of a mold attaching portion according to a parting injection position.

FIG. 4 is a vertical cross-sectional view showing a molded state of a pair of divided bodies.

5 is a cross-sectional view taken along the line VV of FIG.

FIG. 6 is a vertical cross-sectional view showing a joined state of the divided bodies.

7 is a cross-sectional view taken along the line VII-VII in FIG.

FIG. 8 is an enlarged cross-sectional view of a different type hollow molded product.

FIG. 9 is an exploded perspective view showing a modified embodiment of the present invention.

FIG. 10 is a cross-sectional view showing a state where the mold is attached.

FIG. 11 is a perspective view showing a float valve which is an example of a different type hollow molded product.

12 is a vertical sectional view taken along the line XII-XII in FIG.

FIG. 13 is a vertical cross-sectional view of a mold showing a molding state of each divided body.

14 is a cross-sectional view taken along the line XIV-XIV in FIG.

FIG. 15 is a vertical cross-sectional view of a mold showing a joined state of each divided body.

16 is a horizontal cross-sectional view taken along the line XVI-XVI in FIG.

[Explanation of symbols]

 1 Molding Machine 9 First Mold 9a Core 9b Cavity 13 Hollow Molded Product 13a / 13b Divided Body 13d Joint 21 Second Mold 21a Cavity 21b Core 23 First Injection Device 27 Second Injection Device 31 First Molding Space 33th 2 molding space

Claims (8)

[Claims] 1. A first mold, which is movably mounted on the fixed side, is provided with a core that matches one of the divided bodies and a cavity that matches the other divided body that make up the hollow molded product, and at the same time, on the movable side. The second mold is provided with a cavity and a core opposed to the core and the cavity of the first mold, and the fixed side with respect to the first molding space formed by the one core and the cavity in the clamped first and second molds. The first injection device attached to the first injection unit centrally injects the first synthetic resin, and the second injection device is disposed laterally of the molding machine with respect to the second molding space including the other core and the cavity. Parting injection of a second synthetic resin different from the above synthetic resin to mold different kinds of divided bodies respectively, and then moving the first mold opened to move one divided body held in the cavity. Second mold The mold is clamped against the other divided body held in the cavity, and then the synthetic resin injected from the first or second injection device is fused to the abutting portion of each divided body to form a hollow inside. A method for molding a heterogeneous hollow molded product, which comprises molding a hollow molded product having a portion. 2. A first mold mounted on the fixed side is provided with a core that matches one of the divided bodies and a cavity that matches the other divided body that make up the hollow molded product, and is movable on the movable side. The supported second mold is provided with a cavity and a core facing the core and the cavity of the first mold,
The first synthetic resin is center-injected from the first injection device attached to the fixed side with respect to the first molding space consisting of the one core and the cavity in the clamped first and second molds, and the other core Parting injection of a second synthetic resin different from the first synthetic resin from a second injection device arranged on the side of the molding machine with respect to a second molding space consisting of After each molding, the mold opened second mold is moved, and the other divided body held in the cavity is opposed to the one divided body held in the cavity of the first mold, and the mold is clamped. Then, a method for molding a different type hollow molded product in which a synthetic resin injected from the first or second injection device is fused to the abutting portion of each divided body to mold a hollow molded product having a hollow portion inside. . 3. The method for molding a heterogeneous hollow molded article according to claim 1, wherein a fixed first mold is provided so as to be movable in the vertical direction, and the first mold is selectively opposed to the second mold. 4. The method for molding a heterogeneous hollow molded article according to claim 1, wherein the first mold on the fixed side is provided so as to be movable in the horizontal direction, and is selectively opposed to the second mold. 5. The first synthetic resin is center-injected from the first injection device to the abutting portions of the divided bodies abutted by the movement of the first mold, and the mutual fusion is performed. Molding method for different kinds of hollow molded articles. 6. The fusion molding method according to claim 1, wherein the second synthetic resin is parting-injected from the second injection device to the abutting portions of the divided bodies abutted by the movement of the first mold. A method of molding different types of hollow molded articles to be worn. 7. The method for molding a heterogeneous hollow molded article according to claim 5 or 6, wherein the synthetic resin that fuses the abutting divided bodies has a higher melting temperature than the synthetic resin injected from another injection device. 8. The synthetic resin according to claim 5, wherein the abutting divided bodies are fused to each other, and the synthetic resin has elasticity when cured, and the synthetic resin injected from another injection device is hard when cured. The method for forming different types of hollow products.