JP2920150B2 - Method for forming hollow body product and mold device used for carrying out the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention forms a pair of first and second hollow body components by primary molding, and joins the first and second hollow body components formed by primary molding. To form a hollow body product by joining them by secondary molding, and a mold apparatus used for carrying out this forming method.

[0002]

2. Description of the Related Art As a method for producing a synthetic resin hollow body product such as a polytank, a brake fluid tank, a spray tank, and a buoy, a molding method using a hollow molding machine, a molding method using an injection molding machine, and the like are known. In the case of manufacturing a hollow body product by an injection molding machine, the hollow body product is formed as a divided hollow body component or divided body in the primary formation, and the divided surfaces are abutted in the secondary formation, and the abutted portion Is heated or welded to produce one hollow product. According to the molding method using this injection molding machine,
Although it is possible to produce a completely sealed hollow body product, it is also possible to produce a hollow body product having a uniform thickness, and it is possible to cope with complicated shapes. JP-A-62-87315 has further improved the above-mentioned molding method and provided a method for molding a hollow article suitable for mass production. To perform this method, a set of molds is used. One mold is provided with a male mold and a female mold for forming one hollow body component, and the other mold has
A female mold and a male mold for forming the other hollow body component are provided. Using this one set of molds, a pair of hollow body components are formed, and after joining surfaces of these hollow body components are joined to each other, a molten resin is injected into the periphery of the butted surface to be integrated to form a hollow. Gets body products.

[0003]

According to the above-mentioned molding method, one mold is slid or rotated with respect to the other mold to butt a pair of hollow body components, and a molten resin is injected near the butt. By doing so, a hollow body product can be obtained, so that there is an advantage that each step can be automated and the hollow body product can be mass-produced. In addition, since a pair of hollow body components are formed by injection molding, a hollow body product having a complicated shape can be formed.
Thus, there are numerous advantages, but improvements have been found. That is, according to the above-described method, a pair of hollow body components are joined by joining their joints, and by injecting a molten resin into the joined portion, the joining is performed. May not have sufficient strength.

The strength of the joint is to increase the injection pressure when injecting the molten resin during the secondary molding to improve the adhesion between the joint of the hollow component and the resin injected in the secondary molding. Can be increased to some extent. In addition, by injecting the same resin as the hollow body component during the secondary molding, it is possible to increase the fusibility. However,
In order to increase the injection pressure, the mold for secondary molding must be strong, and if the injection pressure is increased, the hollow body component obtained by the primary molding may be deformed. . Furthermore, if the same resin is injected during the secondary molding, the selection of the resin becomes inflexible.
Further, in the conventional molding method, when the area of the joint is small, sufficient joint strength may not be obtained. As described above, the conventional method for forming a hollow body product is not suitable as a method for manufacturing or forming a large or medium-sized tank such as a kerosene tank, which requires relatively high joint strength. . The present invention has been proposed in order to improve the above-described problems, and specifically, a mold for secondary molding or the like does not require exceptional strength, and the area of the joint is small. It is an object of the present invention to provide a molding method suitable for manufacturing a hollow body product having sufficient joint strength and a mold apparatus used for carrying out the method.

[0005]

According to the first aspect of the present invention,
In order to achieve the above object, in the primary molding, a pair of first and second hollow body components are joined to each joint by a pair of dies, and a projection-like engagement portion and a through-hole engagement. In the secondary molding, the joints of the first and second hollow body components formed by the primary molding are formed,
One of the first and second hollow body components is required
The elements are opposed to each other while being held by the mold used for the primary molding, the engaging portions are engaged with each other, and the one protruding engaging portion is heated and deformed into a bulging shape. It is configured to be fixed to the other through-hole engaging portion to obtain a hollow body product. According to a second aspect of the present invention, in the primary molding, a pair of the first and second hollow body components are formed by a pair of dies, and a joint portion of one of the first hollow body components can be bent. And the other second hollow body component is formed so as to have a peripheral portion , and in the second molding, the first and second moldings formed by the primary molding are formed. The joint of the hollow body component is connected to one of the first and second hollow body components.
The components are opposed to each other while being held by the mold used for the primary molding, and the bendable engagement portion of one first hollow body component is connected to the other second hollow component. the peripheral portion of the hollow body component pressurized
It is configured to obtain a hollow body product by heat , bending and fixing. According to a third aspect of the present invention, a hollow body product is obtained by welding or fusing the fixed portion of the engaging portion according to the first or second aspect. According to a fourth aspect of the present invention, a hollow body product is obtained by primary molding and secondary molding.
A mold device, comprising a fixed mold and a movable mold, one of these molds, a core,
The recess and the predetermined distance, and the other mold,
A recess cooperating with the core is provided, and when the mold is clamped, primary molding is performed by the core and the recess.
In the first cavity first hollow body component to be molded is molded, and between the recess and the other mold, the
As described above, the second cavity in which the second hollow body component formed by the primary molding is formed is formed, and at the same time , around the core of the one mold, 2 is formed. During the next molding
A cavity for forming a protruding engagement portion deformed by the thermal deformation means, and around the recess, a secondary molding is performed.
The protruding engagement portion is a core for molding a through hole-shaped engaging portion which engages are provided respectively. The invention according to claim 5 is a hollow body product formed by primary molding and secondary molding.
A mold device for obtaining a fixed mold and a movable mold, one of these molds,
At a core and spacing and have a predetermined concave and the other mold, the core and cooperating with recesses provided respectively, when the mold is mold clamping, the said core and the recess, 1
A first cavity in which a first hollow body component formed in the next molding is formed, and a second hollow body similarly formed in the first molding is provided between the concave portion and the other mold. Second cavities, each of which is formed so that the component has a peripheral portion, are formed, and the periphery of the second hollow body component is formed around the core of the one mold at the time of secondary molding.
A cavity is provided for forming an engaging portion that can be bent by the heating deformation means with respect to the edge .

[0006]

The invention according to claims 4 and 5 operates as follows. That is, the movable mold is clamped to the fixed mold. Then, the first cavity in which the first hollow component is molded by the core and the concave portion, and the second cavity in which the second hollow component is molded between the concave portion and the other mold.
Each cavity is formed. Then, the molten resin is injected into the first and second cavities. Then, the first hollow component is formed by the first cavity, and the second hollow component is formed by the second cavity. Protruding engagement portion which is deformed by the heat deformation means during secondary molding in the first hollow body component in the invention of claim 4, wherein this time, also in the second hollow body components, the Protrusion
A through- hole-shaped engaging portion with which the engaging portion of the shape engages is formed. Open the mold, take out the second hollow body component, for example,
Match to the first hollow body component. That is, first, second
The engaging portions of the hollow body component are engaged with each other . Deformed and fixed to the I Ri bulging shape heat deformation means protruding engagement portion in a state where the engaged. Thereby, the first and second hollow body components are integrated. Remove the hollow body product. Hereinafter, the same operation is repeated to obtain a hollow body product. According to the fifth aspect of the present invention, for example, when the second hollow component is formed by secondary molding,
The heat deformation means, the peripheral portion of the second hollow body component
The engaging portion capable folded is molded to, open the mold, eject the second hollow body components, matched to the first hollow body component. Then, the engaging portion that can be bent in the fitted state is bent and fixed to the peripheral portion of the second hollow body component. Thereby, the first and second hollow body components are integrated to obtain a hollow body product. Repeat the same operation below
To obtain a hollow body product .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A molding method according to this embodiment is a primary molding method in which a pair of split first and second hollow body components are molded by respective molds, and a primary molding method obtained by this primary molding method. And a secondary molding method for producing a hollow body product by bulging or bending an engaging portion of a joint between the pair of first and second hollow body components. Alternatively, a secondary molding method of manufacturing a hollow body product by deforming the engaging portion and fusing or welding the vicinity of the engaging portion. The type of resin for molding the pair of first and second hollow body components and the type of resin fused in the secondary molding are not particularly limited. For example, a pair of first and second hollow body components can be molded with polyphenylene sulfide PPS, and polyamide PA, nylon PA6, polyphenylene sulfide PPS, polycarbonate PC, polybutylene terephthalate PBT, or the like can be applied to secondary molding. When the same type of resin is used for the primary molding and the secondary molding, the resin is well-adjusted, and the weldability of the joint is improved even when injected at a low temperature and a low pressure. Further, since the type of the resin is the same, there is an advantage that the resin can be melted and recycled as it is. In the present embodiment, the mold apparatus used for carrying out the above-mentioned molding method is composed of a fixed mold, a movable mold, a caulking device, a robot and the like, as shown in FIG.

First, an embodiment of the mold apparatus will be described.
As shown in FIG. 1, the mold apparatus includes a fixed mold 1 on the fixed platen side, a movable mold 10 on the movable platen paired with the fixed mold 1, a hollow body component or a hollow body product. It comprises a robot 20 for taking out, a caulking device 30 used for secondary molding, and the like.

Above the stationary mold 1 in the figure, a core 2 for molding a first hollow component A of a synthetic resin hollow product S in cooperation with a cavity of a movable mold 10 described later. Is provided. The core 2 is formed in a substantially rectangular parallelepiped shape, and is provided so as to protrude from a parting line of the fixed mold 1. Therefore, the first hollow component A formed by the core 2 has a box shape. Around the core 2, a plurality of small-diameter, rivet-shaped cavities 3 for molding a body portion are provided at predetermined intervals.
3,... Are provided. These cavities 3, 3,
Are deeper than a second cavity 9 described later. Below the core 2, a shallow second concave portion 4 is provided. This second
The recess 4 forms the second cavity 9 in cooperation with the core or parting surface of the movable mold 10. The second cavity 9 allows the second hollow body component B of the hollow body product S to be formed.
Is molded. Since the second recess 4 is formed as a shallow mere depression, the second hollow component B formed in the second cavity 9 also has a plate shape or a lid shape.

At the periphery of the second concave portion 4, there are provided cores 5, 5,... For forming through holes. Core 5 for through-hole molding,
5,... Are rivet-shaped cavities 3 for molding the body,
, And are provided at the same pitch as the cavities 3, 3,. And the core 5 for through-hole molding,
The outer diameter of 5,... Is larger than the inner diameter of the cavities 3, 3,. The fixed die 1 is provided with ejector pins 6, 6 which can be moved forward and backward, and a second mold 4 is formed in the second cavity 4.
The hollow body component B of these ejector pins 6
Is to be taken out. A sprue 7 having a gradient of about 3 to 6 degrees is provided at a substantially central portion of the fixed mold 1.
The resin injected from the nozzle 8 of the injection machine passes through the sprue 7 to the second cavity 9, which will be described later.
The cavity 12 is filled.

The movable mold 10 is provided with a concave portion 11 that forms a pair with the core 2 of the fixed mold 1. The diameter of the recess 11 is larger than the diameter of the core 2 by a predetermined amount, and is deeper than the protrusion of the core 2. Therefore, when the movable mold 10 is clamped to the fixed mold 1, the first cavities 12 are formed at predetermined intervals between the inner peripheral surface of the concave portion 11 and the outer peripheral surface of the core 2. Thus, the first hollow body component A having a predetermined thickness is formed. The movable mold 10 is also provided with ejector pins 13, 13,.
The first hollow body component A, that is, the hollow body product S is taken out by these ejector pins 13, 13,...

In the present embodiment, the mold apparatus also includes a robot 20 for taking out the first and second hollow body components A and B and the hollow body product S. Also, a caulking machine 30 used for secondary molding is provided. Although the main body of the robot 20 is not shown, a first arm 21 extends from the main body, and a second arm 22 is pivotally attached to the first arm 21. And, for example, a vacuum suction disk 23 is provided at the tip of the second arm 22. The caulking machine 30 also has, for example, an arm 31 operated by a robot. A frame 32 is attached to the tip of the arm 31. A plurality of caulking tools 33, 33,... To be heated by a heater are attached to the frame 32. The caulking tools 33, 33,... Correspond to the number and intervals of the rivet-shaped cavities 3, 3,. And
The tip of the caulking tool 33, 33,.
A hemispherical recess 34 larger than the diameter of 3,... Is formed.

Next, a description will be given of a molding method for manufacturing a synthetic resin hollow body product S using the above-described mold apparatus. The movable mold 10 is abutted against the fixed mold 1 and the mold is clamped by a conventionally known means. Then, the state shown in FIG. 2 is obtained. That is, the core 2 of the fixed mold 1 is located in the recess 11 of the movable mold 10, and the first cavity 1 is formed by the core 2 and the recess 11.
2 are formed. At this time, the first cavity 12 and the rivet-shaped cavities 3, 3,.
Further, the second concave portion 4 of the fixed mold 1 is closed by the parting surface of the movable mold 10 to form the second cavity 9. And, although not shown exactly in the drawing, these first and second cavities 12, 9 and the like communicate with the sprue 7 through a gate.

From the nozzle 8 of the injection machine, the plasticized molten resin J is injected into the sprue 7. The molten resin J is supplied from the sprue 7 to the first cavity 1 through a runner, a gate, and the like.
2. The cavities 3, 3,... And the second cavity 9 for forming a rivet-shaped body are filled. FIG. 3 shows the state after the injection filling. This completes the primary molding. When the molten resin J is cooled and fixed, as shown in FIG. 4, the first hollow body component A is formed by the first cavity 12, and a plurality of engaging members are formed around the open end, that is, the joint. The rivet-like projections k, k,... Are formed simultaneously. Further, a second hollow body component B is formed in the second cavity 9, and the surrounding through holes h,
h,... are formed simultaneously.

Next, the mold opening process is started, and the movable mold 10 is separated from the fixed mold 1. Then, as shown in FIG. 4, the second hollow body component B is sucked by the suction disk 23 of the robot 20, and the first arm 21 is driven to move the movable mold.
Held in 10 to the first aligned with the hollow body component A state is. That is, the first hollow body component A
, Through the through holes h, h,... Of the second hollow body component B, and the second hollow body component B at the joint of the first hollow body component A. Butted surfaces, ie, joints. Then, the rivet-like projections k, k, ...
Is in a state of protruding from the outer surface of the second hollow body component B. This state is shown in FIG. Therefore, FIG.
, The caulking machine 30 is advanced between the fixed mold 1 and the movable mold 10, and the recesses 34, 34,... Of the caulking tools 33, 33,. .. Are pressed against the tips of the projections k, k,. The tip has a large deformation like the head of a rivet, and the caulked parts r, r,
Are formed. Thus, the first and second hollow body components A,
B becomes one body. Then, as shown in FIG.
The ejector pins 13, 13, and 14 protrude, and the hollow product S made of synthetic resin is taken out of the movable mold 10. Then, the molded body P formed by the sprue 7 is cut and eliminated,
A synthetic resin product S shown in FIG. 9 is obtained.

According to the present embodiment, the first and second hollow body components A and B are integrated by deforming the tips of the rivet-like projections k, k,... Like a rivet head. The strength of the joint is large. Therefore, it is excellent as a molding method for large tanks and the like. Further, in the first molding, the first and second hollow body components A and B are simultaneously molded in the same molds 1 and 10, so that the efficiency is high and mass production is possible. Furthermore, since the secondary molding is performed with the same molds 1 and 10, the effect that the mold can be manufactured at low cost and the hollow body product S can be manufactured at low cost can be obtained.

In this embodiment, rivet-shaped projections k, k,... Are formed on the first hollow body component A, and through holes h, h,. However, conversely, even if the through holes h, h,... Are formed in the first hollow body component A and the rivet-shaped projections k, k are formed in the second hollow body component B, the same can be achieved. it is obvious. Further, in the present embodiment, the first hollow body component A is formed into a hemispherical shape and the second hollow body component B is formed into a plate shape, but the second hollow body component B is also formed into a hemispherical shape. Obviously, it can be formed into a shape. At this time, in the secondary molding, the second
May be moved toward the first hollow body component A. Furthermore, in the secondary molding, another mold or holder can be used. Further, in the above embodiment, the rivet-shaped projections k, k,... Were deformed by the heated caulking tool, but the second hollow body component B was vibrated by the caulking tool using the ultrasonic vibrator. hand,
Can be caulked by frictional heat generated in the rivet-like projections k, k,... Engaged with the through holes h, h,. In addition,
Although not shown in the drawing, when the joining portion of the second hollow body component B is brought into contact with the joining portion of the first hollow body component A, an O-ring is interposed, and a highly airtight hollow body product is provided. S
Can also be manufactured.

In the above-described embodiment, the rivet-shaped projections k,
The first and second hollow body components A and B are integrated by deforming the tip of k,... like the head of a rivet, but the shapes of the rivet-like projections k, k,. It is clear that the present invention can also be carried out with the above configuration. When the tip of the rivet-shaped projections k, k,... Is deformed by heating, the heating temperature and the heating time are increased, and the rivet-shaped projections k, k,.
.. And a part of the through holes h, h,. Further, it is also possible to inject and fuse a resin to a portion where the rivet-shaped protrusions k, k,... And the through holes h, h,. At this time, a part of the joint can also be welded at the same time. In the above embodiment, the rivet-like projections k, k,... Were formed on the first hollow body component A, and these rivet-like projections k, k,. FIG. 8 shows an embodiment in which a part of is modified. FIG. 8 does not show an embodiment such as a mold for forming the first and second hollow body components A ′ and B ′, a device for deforming, and the like. A flange Tb extending in a radially outward direction is formed at an open end portion, that is, a joint portion of the body component A ′, and an engaging portion Ke indicated by a two-dot chain line is formed upward from an outer peripheral side surface of the flange Tb. I have. The engaging portion Ke is formed in a shape divided into a plurality of portions, and the inside thereof has a convex portion T as shown in FIGS.
Alternatively, an uneven portion To is formed. The second hollow body component B 'paired with the first hollow body component A' is also formed into a plate shape in this embodiment, and a concave portion W or a convex and concave portion Wj is formed on the upper surface of the joint. ing. Also in this embodiment, in the first molding, the first and second hollow body components A ′ and B ′ are simultaneously molded in respective dies. Then, as described above, one second hollow body component B 'is superimposed on the other first hollow body component A' via an O-ring R or the like as shown in the drawing. Then, the engaging portion Ke is bent on the peripheral edge of the second hollow body component B ′ while being heated by, for example, a tool equipped with a heater, and integrated to obtain a hollow body product S ′. According to the present embodiment, the convex portion T or the concave / convex portion To of the engaging portion Ke formed on the first hollow body component A ′ is replaced with the concave portion W or the convex concave portion Wj of the second hollow body component B ′. And therefore, it is excellent as a method for molding a hollow body product that requires the strength of the joint. It is apparent that the present embodiment also provides the same effects as the above-described embodiments as a whole.

[0019]

As described above, according to the present invention, in the primary molding, the first and second hollow body components are molded with a pair of dies so as to have an engaging portion at each joint, and 2
In the next molding, the joint between the first and second hollow body components formed by the primary molding is replaced with a pair of first and second hollow body components.
One of the hollow body components is held in the mold used for the primary molding.
The engaging portions are engaged with each other while being held, and the engaging portions are heated, deformed and fixed or bent and fixed in a swollen state, and the first and second hollow body components are formed. Since the hollow body product is manufactured by being integrated, a hollow body product having a larger joint strength can be manufactured as compared with a conventional hollow body product obtained by simply welding or fusing the joint. Therefore, special strength is not required for the mold and holder for the secondary molding, and using the mold used for the primary molding ,
Even if the area of the joint is small, a hollow body product having a large joint strength can be manufactured at low cost . According to the invention of the mold apparatus, one of the molds is provided with a core for forming the first hollow body component and a concave portion for forming the second hollow body component, and The mold is provided with a concave portion cooperating with the core, and a cavity and a core for forming an engaging portion are also provided. The elements can be molded simultaneously in the primary molding so as to have engaging portions. Moreover, since the first and second hollow body components are molded in separate first and second cavities, for example, the second hollow body component molded in the second cavity is
In accordance with the first hollow body component while remaining in the first cavity, secondary molding to deform the engaging portion in heat distortion means is also an effect that can be inexpensively implemented in the same mold.

[Brief description of the drawings]

FIG. 1 is a partially cutaway sectional view showing an embodiment of a mold device of the present invention in an exploded manner.

FIG. 2 shows a state where a mold of the mold apparatus is clamped.
It is a partially cutaway sectional view.

FIG. 3 is a partially cutaway sectional view showing a state in which a molten resin is injected into a mold of a mold apparatus.

FIG. 4 is a sectional view showing a state in which a mold is opened and a second hollow body component is being taken out by a robot.

FIG. 5 is a sectional view showing a state in which a mold is opened and a second hollow body component is aligned with a first hollow body component.

FIG. 6 is a cross-sectional view showing a state in which the second hollow body component is aligned with the first hollow body component, and a caulking tool is pressed against the tip of the rivet-shaped projection to caulk.

FIG. 7 is a cross-sectional view showing a state where a hollow body product is being taken out.

FIG. 8 is a sectional view showing another embodiment of the engaging portion.

FIG. 9 is a perspective view showing a part of a hollow body product manufactured according to the embodiment.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 fixed mold 2 cavity for forming rivet-shaped protrusion 9 second cavity 10 movable mold 12 first cavity 30 caulking machine (heating deformation means) A first hollow body component B second hollow body component S hollow body product k Rivet-shaped protrusion (engagement part) h Through hole (engagement part)

Claims (5)

(57) [Claims] In the primary molding, a pair of first and second hollow body components (A, B) are joined to respective joints by a pair of dies (1, 10), and a projection-like engaging portion is provided. (K, k...) And a through-hole engaging portion (h, h,...), And the first and second hollow bodies formed by the primary molding in the secondary molding. The joining portion of the components (A, B) is
One of the first and second hollow body components (A, B)
The component (A) is held in the mold (10) used for the primary molding.
So as to face in a state of being, the engaging portion (k, k, ...,
h, h,...) are engaged with each other, and the one protruding engaging portion (k, k...) is heated and deformed in a bulging shape to deform the other through-hole engaging portion (h). , H, ...) to obtain a hollow product (S) . 2. In the primary molding, a pair of first and second hollow body components (A ′, B ′) is connected to a pair of molds (1, 10).
A bendable engaging portion (ke, ke,...) Is provided at the joining portion of one first hollow body component (A ′) , and the second
The hollow body component (B ') is molded so as to have a peripheral portion , and in the second molding, the first and second hollow body components (A', B ') formed by primary molding are formed. the junction of) one
One of the first and second hollow body components (A ′, B ′) of the pair
The mold (1) used for the primary molding of the hollow body component (A ′)
0), and the foldable engaging portions (ke, k) of one first hollow body component (A ′) are opposed to each other.
e) is heated and bent and fixed to the peripheral portion of the other second hollow body component (B ′) to obtain a hollow body product (S 2 ). 3. A method of molding a hollow body product according to claim 1 or 2, wherein the vicinity of the fixed portion of the engaging portion is welded or fused to obtain a hollow body product (S). 4. A hollow article by primary molding and secondary molding.
The mold apparatus comprises a fixed mold (1) and a movable mold (10), and is provided in one of the molds (1, 10) (1). The core (2) and the recess (4) are provided at a predetermined interval, and the other mold (10) is provided with a recess (11) cooperating with the core (2), respectively. When the molds (1, 10) are clamped, the core (2) and the recess (11) form a first hollow body component (A) formed by primary molding. The first cavity (12) to be molded also has the concave portion (4) and the other mold (1).
0), a second cavity (9) in which a second hollow body component (B) , also molded by primary molding, is molded
Together There are formed, around the core (2) of the one mold (1) is 2 TsugiNaru
The cavities (3, 3) for forming the protruding engagement portions (k, k,...) Which are deformed by the heating deformation means (30) during molding.
...), and around the concave portion (4), there is a through-hole engaging portion (h, k) with which the projecting engaging portion (k, k ...) engages during secondary molding . h,...) for forming cores (5, 5,
…) Are provided, respectively. 5. A hollow body product formed by primary molding and secondary molding.
The mold device comprises a fixed mold and a movable mold, and in one of these molds, a core and a recess are provided at a predetermined interval, And the other mold is provided with a recess cooperating with the core, and when the mold is clamped, by the core and the recess,
A first cavity in which a first hollow body component (A ′) formed by primary molding is formed, and a first cavity is similarly formed between the concave portion and the other mold. with the second cavity in which the second hollow body component (B ') is shaped to have a peripheral portion are formed, around the one mold core, said at secondary forming first
Heat deformation of the periphery of the hollow body component (B ') 2
A mold for forming an engaging portion (ke, ke,...) That can be bent by means .