JP2002113785A - Joining structure for hollow body of synthetic resin and mold structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the positive stoppage of leakage of a secondary resin from an inner passage and also the effective prevention of liquid in a hollow body from leaking to the outside, when split block haves of synthetic resin are butted to each other and joined together by filling the inner passage of the butting parts with the secondary resion. SOLUTION: This joining structure is for butting a pair of the split block haves 3 and 4 of synthetic resin the each other, filling the inner passage 71 with molten resin and joining the split block halves 3 and 4 together to obtain the hollow body 1. A projecting part 53 with an almost trapezoidal section is formed along the peripheral edge of the butting part 51 of the upper split block half 3 and a recessed part 63 with a section whose peripheral edge is of an almost trapezoidal shape corresponding to the projecting part 53, is formed along the peripheral edge of the butting part 61 of the lower split block half 4. In addition, under such a state that the projecting part 53 and the recessed part 63 are joined together to butt both split block halves 3 and 4 to each other, the adhering regions of the mutually corresponding inclined faces of the projecting part 53 and the recessed part 63 are formed along the peripheral edges of the butting parts and a gap is formed between the bottom face of the recessed part 63 and the tip of the projecting part 53.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method in which a pair of synthetic resin halves are joined to each other, and a molten resin is filled in an internal passage formed in an abutting portion to join the halves together. The present invention relates to a joining structure of a synthetic resin hollow body and a structure of a mold used for such joining.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a hollow article made of synthetic resin, a pair of halves are first formed of synthetic resin from the viewpoint of strength and rigidity required for a product or complexity of a product shape (so-called synthetic resin). Primary molding), the synthetic resin halves are brought into contact with each other, and the molten resin (so-called, 2) is inserted into an internal passage formed along the periphery of the joined portion.
A so-called two-stage molding method in which the above-mentioned halves are joined to each other to obtain a hollow molded product by injecting and filling the next resin is known (for example, see Japanese Patent Publication No. 2-20410). . Further, there is also known a method in which a step of injecting and filling a molten resin into an internal passage when joining the above-mentioned halves is performed in a mold used for molding the halves. Have been.

[0003] For example, Japanese Patent Publication No. 2-38377 basically provides a male mold part and a female mold part for molding a set of half bodies in one mold, and the other mold. A pair of mold structures in which a female mold portion and a male mold portion opposed to these mold portions are provided in a mold are disclosed, and by using such a mold, each half body can be simultaneously formed. After molding (injection molding), one mold is slid with respect to the other, thereby abutting the halves remaining in the female mold parts, and applying a molten resin to the periphery of the abutting part. There has been disclosed a method in which the two are joined by injection (a so-called die slide injection (DSI) method).

[0004] For example, Japanese Patent Publication No. 7-4830 basically discloses a mold that is openably and closably combined with one another, wherein one mold is rotatable by a predetermined angle with respect to the other. A mold structure for rotary injection molding, in which a mold is provided with a molding part comprising at least one male molding part and two female molding parts in a repetition order of male / female / female in the rotation direction at the predetermined angle. Is disclosed, and by using such a mold, every rotation (for example, forward / reverse) operation,
A method of forming each half-piece and joining the abutted pair of half-pieces so that a finished product is obtained for each rotation operation (so-called die-rotary injection (D)
RI) method).

However, as described above, a pair of halves are first formed first, the synthetic resin halves are abutted against each other, and the molten resin (secondary resin) is inserted into the internal passage of the abutting portion. ), The halves are joined together to obtain a hollow molded article by so-called filling (so-called two-stage molding method). As a result, when the halves are brought into contact with each other, the adhesion of the contact surfaces becomes insufficient. As a result, when the secondary resin is injected and filled into the internal passage, the secondary resin leaks from the contact portion. It may happen that you leave.

In particular, in the case of a hollow container storing or flowing a fluid inside (hollow portion), in order to reliably prevent leakage of the internal fluid, the secondary resin is sufficiently spread in the internal passage to prevent the leakage. It is necessary to secure the packing density to a certain level or more. Accordingly, in such a case, since the filling pressure when the secondary resin is injected and filled into the internal passage is set higher, the above-described leakage of the secondary resin is particularly likely to occur. When such leakage of the secondary resin occurs, it adversely affects the joining strength between the half-pieces, and also adversely affects the air-tightness or liquid-tightness of the hollow container, and further, the flow characteristics of the internal fluid. Become.

For example, an intake manifold that supplies intake air to a combustion chamber of each cylinder of an engine is a considerably large part even in an intake system. Therefore, in order to further reduce the weight around the engine, a conventional light alloy ( For example, it is considered to be formed of a synthetic resin instead of aluminum alloy. In the case of this intake manifold, it is also important to prevent the intake air flowing inside from leaking to the outside of the manifold. However, it is important to prevent the leakage of the secondary resin, particularly the leakage of the secondary resin to the inside of the manifold. Of particular importance.

That is, when the secondary resin leaks into the inside and hardens to the inner peripheral side of the abutting portion, the flow of the intake air is disturbed by the irregularly formed protrusions of the resin. This is because it has a great adverse effect on the characteristics of feeding to the combustion chamber. Further, in the case of a tubular body such as an intake manifold, leakage of the secondary resin into the manifold is relatively difficult to detect (compared to the case of leakage to the outside). This is because it is difficult to remove the leaked resin, which requires a great deal of labor and time.

On the other hand, in the case of a container for storing a fluid therein, such as an oil tank of an automobile, for example, in such a container, it is most important not to leak the internal fluid to the outside of the container. Therefore, the filling pressure of the secondary resin is set as high as possible within a range that does not cause any trouble. Therefore, leakage of the secondary resin is particularly likely to occur. Also in this case, it is preferable to restrict leakage to the inside of the container preferentially from the outside of the container from the viewpoint of difficulty in detecting leakage and removing the leaked resin. In addition, when the product is a hollow body, when the secondary resin is filled into the internal passage, the outer surface of the product is in close contact with the mold wall, so that leakage of the secondary resin to the external surface of the product is compared. It is hard to happen.

The joining structure of the synthetic resin half bodies by the two-stage molding method as described above is disclosed in, for example, Japanese Patent Application Laid-Open No.
Japanese Patent Application Publication No. 14 (hereinafter referred to as Conventional Technique 1) and Japanese Patent Application Laid-Open No. H11-179557 (hereinafter referred to as Conventional Technique 2) mainly aim at preventing displacement of the abutting portion. A structure in which a pair of concave portions and convex portions for positioning are provided on an abutting surface of each half body is disclosed.

[0011]

However, in each of the above-mentioned prior arts, both halves are provided with a convex portion and a concave portion which are combined with each other on an abutting surface of each half. Although it is possible to accurately perform mutual positioning at the time of abutment, since it is primarily intended for positioning, especially when the filling pressure of the secondary resin is set to be relatively high, It is difficult to reliably prevent leakage of the secondary resin into the inside of the molded product (hollow portion side). Therefore, it is necessary to prevent leakage of the secondary resin from the internal passage by a so-called face seal, which is basically obtained by accurately bringing flat abutment surfaces into close contact with each other. There was no fact.

However, as described above, the primary molded halves undergo deformation due to resin shrinkage during cooling and hardening, so that the abutting surfaces when abutting these halves are brought together. It is difficult to ensure sufficient adhesion, and in order to prevent leakage of the secondary resin from the internal passage, the flatness of the mold portion corresponding to the abutting surface is extremely high, and It is necessary to repeat molding trials, grasp the tendency of shrinkage and deformation, and repeat mold adjustment by skilled personnel so that there is no gap between the abutment surfaces, until stable quality can be obtained Required a great deal of time and effort.

[0013] The cause of the leakage of the secondary resin from the internal passage is not only the deformation of the abutment surface due to the contraction of the half body as described above, but also the filling of the secondary resin into the internal passage. And the abutting portion may be loosened due to the deformation of the half body by the filling pressure of. In this regard,
As a result of the inventor's intensive studies, the leakage of the secondary resin due to the loosening of the abutment portion due to such a filling pressure is caused by the gate portion of the resin supply path for injecting the secondary resin into the internal passage or the injected resin. It has been found that the molten resin tends to be generated at a portion corresponding to a so-called weld portion where the molten resin joins in the internal passage.

In order to prevent the leakage of the secondary resin due to the loosening of the abutment portion due to the filling pressure as described above, it is effective to set the setting value of the filling pressure of the secondary resin not too high. is there. However, especially when it is necessary to prevent leakage of the fluid inside the hollow interior of the molded body to the outside with the highest priority, without setting the filling pressure too high,
There is a demand for realizing a joint structure that provides sufficient sealing performance against leakage of an internal fluid to the outside.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problem, and has a molten resin (2) in an internal passage formed along a peripheral edge of an abutting portion between a pair of synthetic resin halves. When a hollow body made of synthetic resin is obtained by filling and joining the two with each other, a joint structure for more reliably preventing leakage of the secondary resin from the internal passage, particularly leakage into the inside of the hollow body. An object of the present invention is to provide a structure of a mold used for joining, and to provide a joining structure capable of more effectively preventing leakage of a fluid inside a hollow body to the outside.

[0016]

For this reason, the joint structure of the synthetic resin hollow body according to the invention of claim 1 of the present application (hereinafter referred to as the first invention) comprises a pair of synthetic resin half bodies. The joint structure is obtained by filling the internal passage formed along the periphery of the contact portion with molten resin and joining the halves together to obtain a synthetic resin hollow body. In such a joint structure, a convex portion having a substantially trapezoidal cross section is provided along the periphery of the abutting portion at one of the abutting portions of the above-mentioned half members, and the abutting portion of the other half is provided. A substantially trapezoidal concave portion whose cross-sectional peripheral shape corresponds to the convex portion is provided along the peripheral edge of the abutting portion in the joint portion, and the two halves are combined by combining the convex portion and the concave portion. When the projections and the depressions are in contact with each other, the number of slopes corresponding to each other is small. Ku and contact region partially each other are in close contact also is formed in a direction along the peripheral edge of the abutment portion, and,
A predetermined amount of gap is formed between the bottom surface of the concave portion and the tip of the convex portion.

Further, the invention according to claim 2 of the present application (hereinafter referred to as “the invention”)
According to a second aspect, in the first aspect, the convex portion and the concave portion are provided between the hollow portion of the hollow body and the internal passage. .

Furthermore, the invention of claim 3 of the present application (hereinafter referred to as third invention)
According to the invention, the joint structure of the synthetic resin hollow body according to
A pair of synthetic resin halves are abutted against each other, and a molten resin is filled into an internal passage formed along the periphery of the abutting portion, so that the halves are joined together and synthesized. A joint structure for obtaining a resin hollow body is premised, and in the joint section, a plurality of the internal passages are provided in a width direction of the abutting portion.

Furthermore, the mold structure for joining a synthetic resin hollow body according to the invention of claim 4 of the present application (hereinafter referred to as a fourth invention) holds each of a pair of synthetic resin half-pieces. A pair of openable and closable dies each having a holding portion to be closed, and by closing the dies and abutting the halves, an internal passage formed along the periphery of the abutting portion is formed. A gate portion for injecting the molten resin is provided in the mold, and by injecting and filling the molten resin from the gate portion into the internal passage in an abutting state of the halves, the halves are separated from each other. A mold structure for obtaining a synthetic resin hollow body by joining, wherein a pressing means capable of pressing at least a back side of a portion of the abutting portion corresponding to the gate portion is provided. Things.

Furthermore, the invention according to claim 5 of the present application.
(Hereinafter, referred to as a fifth invention) according to the fourth invention, wherein the back side of the abutment portion corresponding to a location where the molten resin injected into the internal passage merges in the internal passage is also provided. A pressure means is provided.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an embodiment of the present invention is applied to, for example, a hollow tank-shaped container as an example.
This will be described in detail with reference to the accompanying drawings. First, a first embodiment of the present invention will be described. FIG. 1 is a perspective view schematically showing an overall configuration of a resin hollow tank 1 as a synthetic resin hollow body according to the first embodiment. As shown in this figure, the tank 1 is formed by joining a pair of half-pieces (an upper half-piece 3 and a lower half-piece 4) to each other. Centrally located. An opening 6 for supplying a required fluid to the inside of the tank 1 or discharging the fluid inside the tank 1 is provided at an appropriate position of the upper half body 3. Is screwed with a cover member 5 for closing.

Each of the half bodies 3 and 4 of the tank 1 is formed by injecting a predetermined material resin into a predetermined mold using, for example, an injection molding machine. In the present embodiment, this injection molding is performed using, for example, a nylon resin mixed with glass reinforcing fibers as a material resin.
The overall size of the hollow tank 1 is, for example, about 400 mm in vertical dimension, about 500 mm in lateral dimension, and about 20 mm in height.
0 mm.

FIG. 2 is an explanatory longitudinal sectional view of the upper and lower halves 3, 4 and the corresponding upper and lower dies along the line AA in FIG. 1 in a mold open state. FIG. 3 is an enlarged partial cross-sectional perspective view showing an abutting portion of each half body 3 and 4 before abutting, and FIG. 4 is an enlarged abutting portion of each half body 3 and 4 in a joined state. FIG.
As shown in FIG. 2, the upper and lower dies 10, 20 have concave holding portions 10H, 20 for holding the upper and lower halves 3, 4, respectively.
H are provided, and the upper half body 3 is
And the lower half 50 is held by the holding portion 20H of the lower mold 20, and the upper and lower molds 1 are held.
By closing 0,20, the upper and lower halves 3,
Four are collided.

The dies 10, 20 are divided into half halves 3, 4
A dedicated mold may be prepared for joining and joining the two halves, but the mold for molding the halves used for molding (for example, injection molding) each of the halves 3 and 4 may be used. It can also be used. For example, when forming a pair of halves by the DSI method or the DRI method and joining the two halves together to obtain a synthetic resin hollow body, injection molding of each halves (so-called 1
The relative movement of the mold is performed while holding the halves formed in the pair of molds used in the next injection), and the two halves are brought into abutment with each other, and the internal passage formed in the abutment portion A molten resin is injected (so-called secondary injection) into the inside, and the two halves are joined together. That is, in this case, the forming step of each half and the joining step of both can be performed as one continuous step.

As can be clearly understood from FIGS. 2 and 3, the upper and lower halves 3 and 4 are provided with respective main bodies 30 and 40 having a substantially U-shaped cross-section, and are provided with an outer side from the peripheral base. Flange portions 31 and 41 are formed integrally with each other, and are formed integrally with each other. The outer peripheral edge of each of the flange portions 31 and 41 is formed with a vertical rib extending rearward (anti-abutment side: a side opposite to the abutment portion). 31L,
41L are provided.

The two halves 3, 4 are provided on the front side (abutting side: sides facing and abutting each other) of the flanges 31, 41, respectively.
When they are joined together they are butted against each other (that is,
An abutting portion 51, 61 is formed.
The abutting portions 51 and 61 of the flange portions 31 and 41 include:
At the opposing portions of the abutment surfaces 52, 62 serving as reference surfaces at the time of the abutment, grooves 31S, 4 each having a substantially U-shaped cross section are formed.
1S is provided in a continuous closed loop along the periphery of the abutment portions 51, 61.

Further, the abutting portion 5 of one of the half bodies 3 and 4 (in the present embodiment, for example, the upper half body 3)
1, a convex portion 53 having a substantially trapezoidal cross section is provided continuously along the periphery of the abutment portion 51. On the other hand, in response to this, the abutting portion 61 of the other half body (in the present embodiment, for example, the lower half body 4) has a substantially trapezoidal cross-sectional peripheral shape corresponding to the convex portion 53. Are formed continuously along the periphery of the abutment portion 61.

When the upper and lower molds 10 and 20 are closed and the abutting portions 51 and 52 of the two halves 3 and 4 are combined with each other, as shown in FIGS. The convex portion 53 and the concave portion 63 are fitted with each other, whereby
The two halves 3, 4 are positioned relative to each other. Also,
As described above, the two halves 3 and 4 are combined with each other in a positioning state, so that the respective groove portions 31S and 41S are combined with each other to form a single passage 71 (closed cross section) having a substantially rectangular cross section. An internal passage is formed inside the abutment.

In this state, a predetermined clamping force is applied to the upper and lower molds 10 and 20 to clamp the molds together.
Of the internal passage 7
1 is filled with a bonding resin Rs (secondary resin) in a molten state. The secondary resin is injected and filled into the internal passage 71 by, for example, injecting the secondary resin at a predetermined set pressure using an injection molding machine. Then, by cooling and solidifying the secondary resin Rs, the upper and lower halves 3,
4 are joined in an abutting state.

The secondary resin material to be injected and filled into the internal passage 71 is more preferably a half body 3, 4
The same resin material as that used for the molding is used. As shown in FIGS. 4 and 5, the internal passage is formed in a closed cross-section inside the abutting portion between the two halves 3, 4; Is not limited to the material made of the resin material of the half bodies 3 and 4, but a part of the wall of the passage is formed of a mold. For example, as shown in FIG. 8, an internal passage 81 (secondary resin passage) is formed. When the mold is opened and the product is taken out after injecting and filling the secondary resin Rs into the inside, a part of the secondary resin Rs cooled and solidified in the passage 81 abuts the two halves 3 and 4. It may be exposed along the portion.

In this embodiment, as shown in detail in FIGS. 6 and 7, the convex portion 53 provided on the abutting portion 51 of the upper half body 3 and the abutting portion of the lower half body 4 61 and the abutting portions 51, 6 of the two halves 3, 4.
When the two are combined with each other, they are fitted to each other, and the mold is clamped in this fitted state, so that the inclined surfaces 53a and 53b of the convex portion 53 and the inclined portions 63 corresponding to the inclined surfaces 53a and 53b, respectively. At least a part of the surfaces 63a and 63b is in close contact with each other, and the contact region is formed continuously without interruption in the direction along the periphery of the abutting portion. At this time, the concave portion 63
A predetermined amount of gap E is formed between the bottom surface 63c of the projection 53 and the tip 53c of the convex portion 53.

That is, when the upper and lower molds 10 and 20 are closed and the abutting portions 51 and 52 of the two halves 3 and 4 are combined, the convex portion 53 of the upper half 3 and the lower The concave portion 63 of the side half body 4 is defined by each inner inclined surface 53a, 63
a, and at least one of the outer inclined surfaces 53b, 63b is fitted in a state of contact (in the present embodiment, both of them) (see FIG. 6). In this matching state, the abutting surfaces 52 and 62 of the two halves 3 and 4 have a slight gap D1 (for example, D1 = 0.1 to 0.3 mm) as indicated by phantom lines in FIG. Degree). At this time, the mating surface 1 of the upper and lower dies 10, 20
0f and 20f are separated by a constant gap D2, and the gap D2 is set to be larger than the gap D1 (D2> D1).

Then, from the mold matching state shown in FIG.
By applying a predetermined pressing force to 0, 20 and performing mold clamping, the convex portion 53 of the upper half body 3 is press-fitted into the concave portion 63 of the lower half body 4, and each inner inclined surface is formed. 53a, 63
The two 53 and 63 are fitted together with the a and the outer inclined surfaces 53b and 63b in close contact with each other. At this time,
The shape and dimensional relationship of the two portions 53 and 63 are set such that a predetermined amount of gap E is formed between the bottom surface 63c of the concave portion 63 and the tip portion 53c of the convex portion 53. Therefore, at the time of mold clamping, the front end portion 53c of the convex portion 53 abuts against the bottom surface 63c of the concave portion 63, and the respective inner inclined surfaces 53a, 63a and the outer inclined surfaces 53b, 63b.
It is possible to reliably prevent the adhesion between them from being impaired.

The gap E formed between the bottom surface 63c of the concave portion 63 and the tip 53c of the convex portion 53 is
In consideration of the shrinkage and deformation of each of the half bodies 3 and 4 after molding, the values are determined so that the value obtained at the time of mold clamping does not become a negative value. When producing relatively large molded products,
It is preferable to design the mold so that the gap E is in the range of, for example, E = about 2 to 5 mm (more preferably, E = about 3 to 4 mm). On the other hand, when manufacturing a relatively small molded product, the gap E is, for example, E = 0.2 to 0.2.
It is preferable to set about 3 mm (more preferably, E = about 0.2 to 2 mm).

The convex portion 53 of the upper half body 3 is
After being press-fitted into the concave portion 63, the inner slopes 53a, 63a and the outer slope 5
Even if the adhesiveness between 3b and 63b is lost and the secondary resin Rs leaks from the internal passage 71, the leaked resin Rs
Before leaking into the hollow part 9 of the molded article 1 (tank),
The bottom surface 63c of the concave portion 63 and the tip portion 53 of the convex portion 53
c, it first flows into and accumulates in the above-mentioned gap E, so that the volume of this gap E is preferably set to a certain size or more.

The upper and lower dies 10, 20
Are pressed together until the abutment surfaces 52, 62 of the half bodies 3, 4 abut (until the gap: D1 = 0), and are clamped in that state. At this time, the convex portion 53 of the upper half body 3 and the concave portion 63 of the lower half body 4 are press-fitted with deformation within the elastic range of the material resin or a slight plastic range. Thereby, each inner inclined surface 53a, 6
3a and the outer inclined surfaces 53b and 63b adhere to each other with a certain surface pressure or more, and a strong sealing property is obtained.
The convex part 53 and the concave part 63 are respectively divided into half bodies 3 and 4.
Is formed along the periphery of the abutting portions 51, 61, so that the contact area between the two 53, 63 is continuous without interruption in the direction along the periphery of the abutting portion of the two halves 3, 4. Formed.

In the above embodiment, the convex portion 53 of the upper half body 3 and the concave portion 63 of the lower half body 4 are formed by the inner inclined surfaces 53a, 63a and the outer inclined surface during mold clamping. Although both 53b and 63b are in close contact with each other, at least one of the inner and outer inclined surfaces may be in close contact with each other.

For example, a small error occurs in the diameter of each pitch circle of the convex portion 53 and the concave portion 63, and this error is caused by the elastic range of the material resin of the half bodies 3 and 4 or a slight If it exceeds the plastic range, each of the inner inclined surfaces 53a and 63a and the outer inclined surfaces 53b and 63
b, it is difficult to bring both of them into close contact with each other, but even in such a case, at least one of the inner and outer inclined surfaces is brought into close contact with each other, so that the convex portion 53 and the concave portion 63 are in contact with each other. Sealing properties can be secured between them.

Further, even when a slight shape error including the inclination angle of the inclined surface occurs in the convex portion 53 and the concave portion 63, the shape error is caused by the material of the half bodies 3 and 4 at the time of mold clamping. If it is within the elastic range of the resin or slightly within the plastic range, the above-mentioned shape error is absorbed and the convex portion 53 is absorbed.
And the concave portion 63 can secure the sealing property. Furthermore, in order to ensure the sealing property between the convex portion 53 and the concave portion 63, the inclined surfaces do not necessarily have to be in close contact with each other over the entire surface. If a part of the cross section of the inclined surfaces is in close contact with each other and the contact area is formed continuously without interruption in the direction along the periphery of the abutting portion of the two halves 3, 4, a certain seal Nature can be secured.

As described above, according to the present embodiment, the two halves are formed by the combination of the convex portion 53 and the concave portion 63 provided on the abutment portions 51, 61 of the halves 3, 4. 3,4
The abutting portions 51 and 61 can be provided with a strong sealing property along the periphery thereof, thereby effectively preventing the fluid inside the hollow molded body 1 (tank) from leaking to the outside. When filling the internal passage 71 with the molten resin Rs for joining the halves 3 and 4, the molten resin Rs
1 can be effectively prevented from leaking into the hollow portion 9 or outside the molded body 1. In this case,
The sealability can be provided by using the positioning mechanism between the half bodies 3 and 4 without providing a dedicated mechanism, so that the structure is not complicated.

Next, a second embodiment of the present invention will be described. In the second embodiment, for example, in a synthetic resin hollow body constituting a hollow container such as a tank, a structure for preventing a fluid stored in or flowing through the hollow from leaking to the outside as much as possible. It is related to.
In the following description, the same components as those in the above-described first embodiment are denoted by the same reference numerals, and further description is omitted. FIG. 9 shows an example in which the joining structure of a synthetic resin hollow body according to the second embodiment is applied to, for example, the same hollow tank as that described in the first embodiment. Things.

In the tank according to the present embodiment, a plurality of (for example, 2
The inner passages 107 and 108 of the book are provided side by side in the width direction of the abutting portion. These two internal passages 107, 1
08 are provided independently of each other, and when the molten secondary resin Rs is injected and filled therein, it may be injected and filled simultaneously in one step, or the two internal passages 10 may be provided.
7, 108 can be performed as a completely separate step.

The tank and the two halves 103, 104 of the present embodiment are the same as those of the first embodiment except that a plurality of internal passages are provided at the abutting portions of the halves 103, 104. It is the same as the tank 1 and the half bodies 3 and 4 in the embodiment. Therefore, more preferably, a convex portion 53 and a concave portion 63 similar to those described in the first embodiment are formed on the inner side of the inner internal passage 107, and the seal between the two 53, 63 is formed. This prevents leakage of the secondary resin Rs into the hollow interior 9 and contributes to prevention of fluid leakage from the hollow interior 9 to the outside of the tank.

In this embodiment, the two halves 103, 10
By providing a plurality (for example, two) of independent internal passages 107 and 108 arranged side by side in the width direction of the abutting portion in the abutting portion of the four, a path from the hollow interior 9 of the tank to the outside of the tank is provided. The double sealing by the secondary resin Rs can be realized, and leakage of the fluid from the hollow interior 9 to the outside of the tank can be more reliably prevented.

FIG. 10 shows a joint structure according to a modification of the second embodiment. In this modification, the half body 11
In the abutment part between 3,114, in the width direction,
Not only a plurality (two) of internal passages are provided, but also a plurality (two sets) of sealing mechanisms by a combination of the convex portions 53 and the concave portions 63. That is, each of the inner internal passage 117 and the outer internal passage 118 is provided with a pair of seal mechanisms on the inner side (hollow inner side 9 side) by a combination of the convex portion 53 and the concave portion 63.

According to this modification, a plurality (for example, two)
The internal passages 107 and 108 are provided side by side in the width direction of the abutting portion, so that the hollow interior 9
, A double seal made of the secondary resin Rs can be realized on the path extending from the inside of the tank to the outside of the tank. Leakage of the fluid from 9 to the outside of the tank can be more reliably prevented, and leakage of the secondary resin Rs to the hollow interior 9 can be more reliably prevented.

FIG. 11 shows a joint structure according to another modification of the second embodiment. In another modified example, only one internal passage 127 is provided at the abutting portion between the half bodies 123 and 124.
27 has a substantially H-shaped cross section. According to such a structure, even if there is one internal passage 127, the secondary resin Rs
As a result, it is possible to secure a large contact area between the two halves 123 and 124, and as a result, it is possible to increase the bonding strength between the two halves 123 and 124. In addition, since a very wide seal portion made of a secondary resin Rs can be provided in a path extending from the hollow interior 9 of the tank to the outside of the tank, leakage of fluid from the hollow interior 9 to the outside of the tank can be more effectively prevented. can do.

Next, a third embodiment of the present invention will be described. The third embodiment relates to the structure of a mold used for manufacturing a synthetic resin hollow body such as a hollow tank formed by joining a pair of halves, for example.
Molten resin (secondary resin) for joining halves
The present invention relates to a configuration for preventing leakage to the outside and inside of a hollow body as much as possible when injecting and filling into an internal passage.

FIG. 12 shows an example in which the mold structure of the synthetic resin hollow body according to the third embodiment is applied to, for example, the production of the hollow tank 1 described in the first embodiment. This is shown. As shown in this figure, the upper and lower molds 210 and 220 according to the present embodiment have the respective halves 3 and 4 when the holders 210H and 220H hold the halves 3 and 4, respectively. 4, pressing pins P1, P2, and P3 for pressing the respective flange portions 31, 41 toward the abutment side from the back side at locations corresponding to the back side (anti-abutment side) of the flange portions 31, 41. , And P4 are arranged in pairs vertically and slidable up and down.

For example, taking the upper pressure pins P1 and P2 as an example, the pressure pins P1 and P2 are held in a state where the upper half body 3 is held by the holding portion 210H of the upper die 210, And P2 are set so that the front end surfaces thereof abut against the back surface of the flange portion 31 and, more preferably, fit between the outer side surface of the main body portion 30 of the upper half body 3 and the vertical rib 31. The lower pressure pins P3 and P4 are similarly set. The upper pressure pins P1 and P2 and the lower pressure pins P3 and P4 are paired up and down with the upper pressure pin P1 and the lower pressure pin 3;
2 and the lower pressure pin 4 are positioned so as to form a pair up and down.

The upper and lower pressure pins P1 and P
2, P3 and P4, at least one pair of upper and lower pressing pins (for example, the upper pressing pin P1 and the lower pressing pin 3) It is provided at a location corresponding to a gate (not shown) for injecting the secondary resin Rs into the internal passage 71 formed at the abutting portion and / or a portion near the gate. More preferably, the other pair of upper and lower pressing pins (for example, the upper pressing pin P2 and the lower pressing pin 4) is used to inject the 2
The next resin is provided at a location corresponding to a location (so-called weld portion) where the secondary resin joins in the closed loop-shaped internal passage 71.

The pressure pins P1 and P
2, P3 and P4 are at least one of upper and lower (in this embodiment, upper pressing pins P1 and P2)
Are pressurizing devices F1 and F2 composed of, for example, hydraulic cylinders or the like.
Respectively. In addition, these pressurizing devices F1,
F2 is connected to a control unit 230 that can control the pressing force, operation timing, and the like, so that signals can be transmitted and received.

On the other hand, the lower pressure pins P3 and P4 are used, for example, after the lower half body 4 is held by the holding portion 220H of the lower mold 220, or when the upper and lower half bodies 3 and 4 are connected to each other. After the abutment, it is fixed at the set position described above. Note that a cylinder for adjusting the vertical position may be connected to the lower pressure pins P3 and P4. Alternatively, the lower pressing pins P3 and P4 are also connected to the pressing device like the upper pressing pins,
A pressing force may be applied.

In the above configuration, the upper and lower molds 210,
After the molds 220 are matched with each other and the half bodies 3 and 4 are abutted with each other and the mold is clamped in the abutted state, when the secondary resin is injected and injected into the internal passage 71, the injection and injection are performed. Prior to the above, the lower pressing pins P3 and P4 are fixed at the set position, and then the pressing devices F1 and F2 are driven according to the injection timing to apply a pressing force to the upper pressing pins P1 and P2. It is made to let.

Thus, when the secondary resin is injected and injected into the internal passage 71, the injection pressure surely prevents the abutment portion from being loosened, and the secondary resin is allowed to flow into the internal passage 71.
Can be more effectively prevented from leaking out around. In particular, by providing the above-described pressurizing mechanism for the gate portion and / or the vicinity thereof, where the leakage of the secondary resin is relatively likely to occur, and the so-called weld portion,
Leakage of the secondary resin in such a portion can be more effectively prevented.

In the third embodiment, the pressing pins P1, P2, and P3 are provided on the back side of the flange portions 31 and 41 of each half body 3 and 4 (that is, on the back side of the abutting portion). And P
4 is provided with an engaging portion for engaging the distal end side of the pressing pins P1 and P2.
The shape is not limited to the hole-like shape corresponding to the shape of the tip side of P3 and P4, and may be a groove-like shape extending along the peripheral shape of the abutting portion. In this case, the shape of the pressure member is not limited to the pin shape, but may be a block shape having a certain length in the direction along the peripheral edge of the abutting portion.

In the above embodiment, the tank-shaped synthetic resin hollow body is manufactured.
It is effective for all other synthetic resin hollow bodies as long as it is made by joining a pair of halves and filling the internal passage of the abutting part with molten resin and joining the two halves together. Can be applied to As described above, the present invention is not limited to the above-described embodiment, and it goes without saying that various improvements or design changes can be made without departing from the gist of the present invention.

[0058]

According to the first aspect of the present invention, a convex portion having a substantially trapezoidal cross section is provided along the periphery of the abutting portion at one of the abutting portions of the pair of half bodies. At the same time, the abutting portion of the other half has a substantially trapezoidal concave portion whose cross-sectional peripheral shape corresponds to the convex portion along the periphery of the abutting portion. At the time of abutment, these convex portions and concave portions are combined so that both can be positioned. At least a part of the inclined surfaces corresponding to each other between the concave portion and the concave portion is formed in a direction along the periphery of the abutment portion, so that a strong sealing property is provided along the periphery of the abutment portion. Can be provided. At this time, since a predetermined amount of gap is formed between the bottom surface of the concave portion and the distal end portion of the convex portion, it is ensured that the bottom surface and the distal end abut against each other and the adhesion of the contact region is impaired. Can be prevented. That is, by the combination of the convex and concave portions provided in the abutting portion of the half body,
The abutting portion between the two halves can be provided with a strong sealing property along the periphery thereof, effectively preventing the fluid inside the hollow molded body from leaking to the outside. When filling the internal passage with the molten resin to be joined, it is possible to effectively prevent the molten resin from leaking from the internal passage into the hollow portion or the outside of the molded body. In this case, the sealing property can be provided by using the positioning mechanism between the half bodies without providing a dedicated mechanism, so that the structure is not complicated.

According to the second aspect of the present invention, basically, the same effects as those of the first aspect can be obtained. In particular, since the convex portion and the concave portion are provided between the hollow portion of the hollow body and the internal passage, when filling the internal passage with the molten resin for joining the two halves, the molten resin is not Leakage from the internal passage into the hollow portion can be effectively prevented.

Further, according to the third aspect of the present invention, a plurality of internal passages for filling the molten resin for joining the two halves are provided in the width direction of the abutting portion between the halves. Because of this, it is possible to realize multiple seals with a joining resin on the path from the hollow part of the hollow body to the outside of the hollow body, and to more reliably prevent leakage of fluid from inside the hollow part to the outside of the hollow body. Will be able to

Further, according to the fourth aspect of the present invention, since the pressing means capable of pressing at least the back side of the portion corresponding to the gate portion of the abutting portion of the half-split bodies is provided, When the molten resin for joining is filled in the internal passage, the filling pressure is driven by driving the pressurizing means for a portion corresponding to the gate portion where loosening of the abutment portion due to the filling pressure is likely to occur. Even if it acts, loosening of the abutment portion can be reliably prevented. As a result, it is possible to effectively prevent the molten resin for joining from leaking from the internal passage.

Further, according to the fifth aspect of the present invention, basically the same effects as those of the fourth aspect can be obtained. In particular, the pressurizing means is provided also on the back side of the abutment portion corresponding to a location (so-called weld portion) where the molten resin injected into the internal passage merges in the internal passage. Along with the part corresponding to the gate,
Even at a portion corresponding to a so-called weld portion where the leakage of the joining resin is likely to occur, it is ensured that the abutment portion is not loosened, and the joining resin is more effectively prevented from leaking from the internal passage. be able to.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an entire configuration of a hollow tank according to a first embodiment of the present invention.

FIG. 2 is an explanatory longitudinal sectional view of each half body along the line AA in FIG. 1 and a mold corresponding to the half bodies in an open state.

FIG. 3 is an enlarged partial cross-sectional perspective view showing an abutting portion of each half before the abutting.

FIG. 4 is an explanatory longitudinal sectional view of each half body along the line AA in FIG. 1 and a mold corresponding to these half bodies in a mold-clamped state.

FIG. 5 is an enlarged partial cross-sectional perspective view showing an abutting portion of the two halves in a joined state.

FIG. 6 is an explanatory cross-sectional view of an abutting portion between the two halves showing a fitting state of a convex portion and a concave portion provided at an abutting portion of the half body before mold clamping.

FIG. 7 is an explanatory cross-sectional view showing, on an enlarged scale, a fitting state of the convex portion and the concave portion when the mold is clamped.

FIG. 8 is a view showing a modification of the internal passage according to the embodiment, and is an enlarged partial sectional perspective view showing an abutting portion of both halves in a joined state.

FIG. 9 is a view showing a joint structure of a synthetic resin hollow body according to a second embodiment of the present invention, and is an enlarged partial cross-sectional perspective view showing an abutting portion of both halves of a tank in a joined state. It is.

FIG. 10 is a view showing a joint structure of a synthetic resin hollow body according to a modification of the second embodiment, and is a partial sectional perspective view corresponding to FIG. 9;

FIG. 11 is a view showing a joint structure of a synthetic resin hollow body according to another modification of the second embodiment, and is a partial cross-sectional perspective view corresponding to FIG. 9;

FIG. 12 is a view showing a mold structure used for manufacturing a synthetic resin hollow body according to a third embodiment of the present invention, and is a cross-sectional explanatory view showing both the mold and an abutting half body. .

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Tank (hollow body made of synthetic resin) 2 ... Joint part 3,103,113,123 ... Upper half body 4,104,114,124 ... Lower half body 9 ... Hollow part of tank 31,41 ... Half Flange portions of split bodies 51, 61: abutting portions of half bodies 52, 62 ... abutting surfaces of half body bodies 53: convex portions of half bodies 53a, 53b: inclined surfaces of convex portions 53c: convex shapes Tip of the portion 63: concave portion of the half body 63a, 63b: inclined surface of the concave portion 63c: bottom surface of the concave portion 71, 81, 107, 108, 117, 118, 127
... Internal passages 210, 220 ... Molds 210H, 220H ... Mold holding parts F1, F2, F3, F4 ... Pressing devices P1, P2, P3, P4 ... Pressing pins Rs ... Secondary resin

Claims (5)

[Claims] 1. A pair of synthetic resin halves are abutted against each other, and a molten resin is filled into an internal passage formed along a peripheral edge of the abutting portion, whereby the halves are joined together. Are joined to obtain a synthetic resin hollow body, a convex portion having a substantially trapezoidal cross-sectional shape is provided along the periphery of the abutting portion at one of the abutting portions of the half body. Along with the abutting portion of the other half, a substantially trapezoidal concave portion whose cross-sectional peripheral shape corresponds to the convex portion is provided along the periphery of the abutting portion, and the convex portion and the concave portion are provided. In a state where the two halves are brought into contact with each other in combination with each other, the contact area where at least some of the inclined surfaces corresponding to each other of the convex portion and the concave portion are in close contact with each other is a peripheral edge of the contact portion. And between the bottom surface of the concave portion and the tip of the convex portion. Structure for joining synthetic resin hollow body, characterized in that the amount of gap is formed. 2. The joint structure for a synthetic resin hollow body according to claim 1, wherein the convex portion and the concave portion are provided between the hollow portion of the hollow body and the internal passage. . 3. A pair of synthetic resin halves are brought into abutment with each other, and a molten resin is filled into an internal passage formed along a peripheral edge of the abutting portion, whereby the halves are brought together. A joint structure for obtaining a synthetic resin hollow body, wherein a plurality of the internal passages are provided in a width direction of the abutting portion. 4. A pair of openable and closable dies each having a holding portion for holding each of a pair of synthetic resin halves, and these dies are closed to bring the halves into abutment. A gate portion for injecting molten resin into an internal passage formed along the periphery of the abutting portion is provided in the mold, and the gate portion is separated from the internal passage by the abutting state of the halves. A mold structure for joining the halves together to obtain a synthetic resin hollow body by injecting and filling a molten resin into the back side of at least a portion of the abutting portion corresponding to the gate portion And a pressurizing means for pressurizing the mold. 5. The pressurizing means is also provided on the back side of the abutment portion corresponding to a location where the molten resin injected into the internal passage merges in the internal passage. Item 6. The mold structure according to Item 4.