JP3232048B2 - Molding method and molding die for molded article made of two materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a relatively small amount of a first material.
Using a fixed mold and a slide mold, a molded article integrated by laminating a first semi-molded article made of resin and a second semi-molded article made of a relatively large amount of second resin is used. The present invention relates to a molding method for obtaining a molded product and a molding die used for performing the molding method.

[0002]

2. Description of the Related Art When a lid, such as a cap for closing an opening of a container or a flange for connecting a pipe for fluid transport, is molded from a synthetic resin, it is molded from a hard material as is well known. In order to prevent the leakage of the internal fluid, a seal such as a seal or packing is used for such a lid.
As is well known, a soft material is used for molding such a seal body. As described above, since the lid and the seal are molded from materials having different properties, generally, the lid and the seal are separately molded in advance, and the seal is manually bonded to the lid after molding. It is integrated. Alternatively, they are simply mounted without bonding. Further, the applicant has disclosed in Japanese Patent Application Laid-Open No. 9-27730, for example.
As proposed in Japanese Patent Application Publication No. 5 (1999) -2005, a molding method of a composite molded article has been proposed, so that this method is applied to firstly form a hard material lid first, and this lid is made of metal. A cavity for molding the seal body while leaving it in the mold,
It is also formed by secondary molding that secures between the inside of the lid and the mold and injects a soft material into the secured cavity.

[0003]

When the sealing member is adhered to or attached to the lid member by the above-mentioned manual operation, the die and the like are inexpensive and the molding process is simplified. However, there is a possibility that the productivity is reduced and the quality of the molded product is not constant. As described above, since the quality is not constant, it is necessary to inspect the seals of all the molded products, and there is a disadvantage that labor costs are increased and the cost is increased as a whole.

[0004] On the other hand, when a molding method of a composite molded article is applied, the productivity is improved and the quality of the molded article is constant. However, there are problems. For example, when two parts are integrated to form a single part, a lid with a large amount of resin is first molded first, and then a resin with a large amount of resin is formed from the technical custom of “attaching a small one to a large one”. It is implemented so that a small number of seals are secondary formed. Even if it is carried out in this way, there is little problem when the shape of the molded product is simple, but since the seal is generally located on the back side of the lid, the cavity for forming the seal in the secondary molding is formed in the lid. It is necessary to secure the space between the inside and the mold, which may complicate the mold and increase the cost of the mold. Also,
The primary molded lid and the secondary molded seal are 2
Part of the lid is melted and fused by the heat of the resin injected at the time of the next molding. However, since the amount of resin or the injection amount of the seal is small, the heat capacity is also small, so that the lid is not melted. Sufficient adhesion may be lost. The present invention has been proposed in order to improve the above-mentioned problems, and specifically, it is possible to inexpensively mold a high-quality and constant-quality molded article made of two materials. It is an object of the present invention to provide a molding method of a molded article made of two materials and a molding die used for performing the method.

[0005]

According to the present invention, in order to achieve the above object, a fixed die and a slide die are used.
In the next molding, a resin with small volume or capacity is injected and 2
In the next molding, it is configured to inject resin with large capacity,
It is also achieved by performing the primary and secondary moldings substantially simultaneously. That is, in order to achieve the above object, the invention according to claim 1 includes a first semi-molded article made of a relatively small amount of the first resin and a second semi-molded article made of a relatively large amount of the second resin. In a first molding using a fixed mold and a slide mold, a first resin is injected to obtain a first semi-molded product, and the second molding is performed by using a fixed mold and a slide mold. With the first semi-molded product held by the slide mold, slide to the secondary molding position and inject the second resin in a form of lamination on the primary semi-molded product to obtain the secondary semi-molded product. A molding method in which a part of a primary semi-molded product is melted and fused with a second resin injected by secondary molding to obtain a molded product in which the first semi-molded product and the second semi-molded product are integrated. The first resin is made of a soft material for forming a seal such as a seal or a packing, and the second resin is made of a lid, a cap, or a filler. The primary molding is performed at a position deviated from the center position of the mold clamping device, and the secondary molding is performed substantially at the center position. 1 resin from the first sprue
And the second resin is configured to be injected substantially simultaneously from the second sprue. According to a second aspect of the present invention, there is provided a fixed mold in which first and second cores and a concave portion are provided on the parting line side, and similarly, first and second concave portions are provided on the parting line side. And a slide mold slidably provided so as to take first and second positions with respect to the fixed mold, wherein the slide mold is in the first position. When the mold is clamped to the fixed mold, a cavity having a relatively small volume is formed by the first concave portion of the slide mold and the first core of the fixed mold, and the second cavity of the slide mold is formed. The recess of the fixed mold and the recess of the fixed mold form a relatively large cavity which is combined with a relatively small cavity, and the slide mold is positioned relative to the fixed mold when the slide mold is in the second position. When you close the mold, A relatively small volume cavity is formed by the second concave portion of the slide die and the second core of the fixed die, and the first concave portion of the slide die and the concave portion of the fixed die are formed. , Are configured to form a relatively large cavity that is mated with a relatively small cavity. According to a third aspect of the present invention, the concave portion of the fixed mold according to the second aspect is provided at a substantially central portion with respect to the mold clamping device, and the first core and the second core are separated from the central portion. It is configured to be provided at a distance position.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of a mold will be described with reference to FIG. As shown in FIG. 1, the mold according to the present embodiment generally includes a fixed mold 1 and a slide mold 20 paired with the fixed mold 1.
The fixed die 1 is fixedly attached to the fixed platen 10 via the mounting plate 11, and the slide die 20 is provided so as to be slidably movable vertically with respect to the movable platen 30 in FIG. 1. I have.

On the parting line side of the fixed mold 1,
First and second cores 4 and 7 are formed at predetermined intervals in the vertical direction, and one recess 9 is formed between these cores 4 and 7. Although not shown in FIG. 1, the recess 9 is located substantially at the center of the mold clamping device, for example, at the center of the four tie bars in the case of a toggle-type mold clamping device having four tie bars. It is provided as follows. Therefore, the tree finger pressure when injecting a relatively large amount of molten resin in the secondary molding is
The reaction acts almost equally on the mold clamping device.
The first and second cores 4 and 7 are provided at positions equidistant from the center.

The first and second cores 4 and 7 form a cavity into which a soft material having a small volume is injected in cooperation with a slide mold 20 which will be described in detail. Form the cavity to be injected. Fixed mold 1
On the mounting plate 11 side, a concave groove, that is, a first sprue 2 is formed upward from the central portion in FIG. 1, and the first sprue 2 is opened at a substantially central portion of the first core 4. It is connected to the first runner 3. In addition, fixed mold 1
On the mounting plate 11 side, a second sprue 5 is also formed, which extends downward from the central portion, and the second sprue 5 is also opened at a substantially central portion of the second core 7. It is connected to the second runner 6. Although not shown in FIG. 1, the mounting plate 11 is provided with a switching valve, for example, a slide mold 20 so that the soft material flows toward the first sprue 2 or the second sprue 5. It can be switched in conjunction with the vertical slide of. One sprue runner 8 is formed substantially at the center of the fixed mold 1, and the sprue runner 8 is opened in the recess 9 through a gate.

At the substantially center position of the fixed platen 10, two nozzle touch portions are provided. One of the nozzle touch portions is provided with a first injection device 12 having a conventionally well-known form for soft material injection, and the other is provided with the other. In the nozzle touch portion, second injection devices 13 for injection of a hard material having a well-known structure are also arranged.

On the parting line side of the slide die 20, first and second large-diameter concave portions 21 and 23 having relatively large diameters are formed. And these large-diameter concave portions 21 and 23
A first and a second small-diameter concave portion 22 having a relatively small diameter
24 are formed. These first and second large-diameter recesses 2
1 and 23 cooperate with the first and second cores 4 and 7 and the recess 9 of the fixed mold 1 as described above. Therefore, the first and second large-diameter concave portions 21 and 23 of the slide mold 20 are provided.
Is equal to the distance between the first core 4 and the concave portion 9 of the fixed mold 1 or the distance between the concave portion 9 and the second core 7. In addition, the first and second cores 4 and 7 of the fixed mold 1 enter the first and second large-diameter recesses 21 and 23 of the slide mold 20 at the time of mold clamping. Thereby, the slide mold 20
A cavity k having a small volume for forming a soft material is formed between the small-diameter concave portions 22 and 24 and the distal end portions of the first and second cores 4 and 7 of the fixed mold 1. The first and second large-diameter concave portions 21 and 23 of the slide die 20 and the concave portion 9 of the fixed die 1
Thus, a cavity K having a large volume for forming a hard material is formed. In addition, as is clear from the above description,
The large cavity K is combined with the small cavity k.

The slide mold 20 constructed as described above is supported by a support plate 31 attached to a movable plate 30 so as to be slidable in the vertical direction in FIG. More specifically, the support plate 31
Has upper and lower flange portions 32 and 33. The slide mold 20 is provided between the flange portions 32 and 33 so as to be slidable in the vertical direction. A piston / cylinder unit 35 is attached to a lower flange portion 33 of the support plate 31, and a rod 36 is fixed to a lower end portion of the slide mold 20. Therefore, when the rod 36 of the piston / cylinder unit 35 expands and contracts, the upper end of the slide mold 20 is supported by the support plate 3.
It is driven to a first position in contact with the upper flange 32 of the first and a second position in contact with the lower flange 33. These positions are primary and secondary molding positions as described later. FIG. 1 does not show a mold clamping device, a molded product projecting device, and the like.

Next, an example of forming a molded product P comprising a seal portion S of a soft material and a cap portion C of a hard material using the above-described mold will be described with reference to FIGS. FIG.
As shown in FIG. 3, the slide mold 20 is
The movable platen 30 is clamped to the fixed platen 10 at the position shown in FIG. Then, the seal S is formed by the first core 4 of the fixed mold 1 and the first small-diameter concave portion 22 of the slide mold 20.
Is formed. A separately measured soft resin is injected from the first injection device 12. The soft material is injected from the first sprue 2 through the runner 3 to the small volume cavity k from the gate. The state in which the soft material is filled by the primary molding and the seal portion S is molded in this way is shown in FIG.

Since the seal portion S made of a soft material has a small volume, it solidifies in a relatively short time. Movable platen 3 after solidification
0, so the slide mold 20 is opened. Then, the slide mold 20 is moved by the piston / cylinder unit 35.
To the lower second position. The state where the mold is opened and driven to the second position is shown in FIG.

As shown in FIG. 3A, the seal S formed by the slide mold 20, that is, the first large-diameter concave portion 21 is located at the second position of the fixed mold 1. The concave portion 9 and the second large-diameter concave portion 23 are positions where they are aligned with the second core 7 of the fixed mold 1. Then, the mold is clamped. Then, the seal portion S formed by the slide mold 20 and
The first large-diameter concave portion 21 of the slide mold 20 and the fixed mold 1
A cavity K for forming the cap portion C is formed by the concave portion 9. At the same time, the second
The cavity k for forming the seal S is formed by the small-diameter concave portion 24 and the first core 7 of the fixed mold 1.
The separately measured hard resin melt is supplied to the second injection device 13.
Inject from The hard material is injected into the cavity K from the gate through the sprue runner 8. The cap portion C is formed by the secondary forming. The cap portion C made of a hard material has a large volume and a large heat capacity. Therefore,
A part of the soft material is melted by the heat of the hard material, and the soft material and the hard material are integrated. That is, the seal portion S and the cap portion C are integrated. Similarly, the soft resin is injected from the first injection device 12. The soft material is injected from the second sprue 5 through the runner 6 into the cavity k through the gate. Thus, the molded article P is formed by the secondary molding.
FIG. 3 (a) shows a state in which the sealing member S is formed by filling a soft material by primary forming and forming the seal portion S.

The movable platen 30 is opened after cooling and solidification. The opened state is shown in FIG. When the movable platen 30 is opened, the ejector pins protrude, and the molded product P is protruded.

After the molded product P is taken out, the slide mold 20 is driven by the piston / cylinder unit 35 to the first upper position. The state where the mold is opened and driven to the first position is shown in FIG. At this position, the movable platen 30 is clamped to the fixed platen 10. Then, the cavity k for forming the seal S is formed by the first core 4 of the fixed mold 1 and the first small-diameter recess 22 of the slide mold 20. At the same time, the cavity K for forming the cap C is formed by the seal portion S formed by the slide mold 20, the second large-diameter recess 23 of the slide mold 20, and the recess 9 of the fixed mold 1. Is done. A separately measured soft resin is injected from the first injection device 12. The soft material is injected from the first sprue 2 through the runner 3 to the cavity k from the gate. The hard material is injected from the second injection device 13. The hard material is injected into the cavity K from the gate through the sprue runner 8. Thus, the seal portion S of the soft material and the cap portion C of the hard material are integrated as described above. FIG. 4B shows a state in which the primary molding and the secondary molding are simultaneously performed.

The movable platen 30 is opened after cooling and solidification. The opened state is shown in FIG. When the movable platen 30 is opened, the ejector pins protrude, and the molded product P is protruded. After removing the molded product P, the slide mold 20 is driven by the piston / cylinder unit 35 to the lower second position. The state where the molded article P is taken out and driven to the second position is shown in FIG. At this position, the movable platen 30 is clamped. Then, the second of the fixed mold 1
A cavity k for forming the seal S is formed by the core 7 and the second small-diameter concave portion 24 of the slide mold 20. At the same time, the seal portion S formed by the slide mold 20
The first large-diameter recess 21 of the slide mold 20 and the recess 9 of the fixed mold 1 form a cavity K for forming the cap C. Therefore, when the soft material and the hard material are respectively injected from the first and second injection devices 12 and 13 as described above, the sealing portion S and the cap portion C are injected.
And a seal part S are formed. This state is shown in FIG. Hereinafter, a molded article is formed in the same manner.

Next, the slide die 2 is fixed to the fixed platen 10.
An embodiment in which 0 'is slid will be described with reference to FIG. It should be noted that the same reference numerals are used for the same elements as the constituent elements of the above-described embodiment, and the same reference numbers are given the same reference numerals with dashes “′” for the elements that perform the same functions or functions. According to the embodiment, the slide mold 20 'slides vertically with respect to the fixed platen 10 in FIG. Therefore, in this embodiment, a relatively large diameter core 303 and this core 303 are provided on the parting line side of the slide mold 20 ′.
At a predetermined interval, a large-diameter concave portion 304 having a size matching the core 303 is provided. One of the slide molds 20 ′ corresponds to the first injection device 12, and the other corresponds to the first runner 3 ′ having an opening at the distal end surface of the core 303, and similarly, one corresponds to the second injection device 13. And a second runner 6 ′, the other of which is open to the large-diameter recess 304.

The movable die 300 attached to the movable platen 30 has a relatively large-diameter concave portion 301 opened toward the parting line, and a relatively small-diameter concave portion 302 is formed at the bottom of the concave portion 301. Is formed. The large-diameter concave portion 301 is provided with the large-diameter concave portion 3 of the slide mold 20 ′.
04, and the core 303 of the slide mold 20 'is fitted tightly.
Then, when fitted, the small-diameter concave portion 302 and the slide mold 20 ′
A relatively small cavity k ′ is formed by the tip of the core 303 of FIG.

A seal portion S 'made of a soft material using the above-mentioned mold.
And a molding example of a molded product including a hard material cap portion will be described. The mold is clamped at a position where the slide mold 20 'is at the bottom. Then, as shown in FIG. 6A, the core 303 of the slide mold 20 ′ is moved to the movable mold 3.
The small-diameter concave portion 302 and the distal end of the core 303 of the slide mold 20 'form a relatively small cavity k'. Therefore, the resin of the soft material separately measured is supplied to the first injection device 12.
Inject from The soft material is supplied from the first sprue 2 ′ to the first sprue 2 ′.
Is injected from the gate to the small cavity k 'through the runner 3'. This primary injection forms a soft material seal portion S '.

After the cooling and solidification, the movable platen 30 is opened, and the slide mold 20 'is slid upward. With the seal portion S 'remaining in the movable mold 300, the slide mold 20' is moved to a position where the large-diameter recess 304 of the slide mold 20 'matches the large-diameter recess 301 of the movable mold 300.
Slide up. Then, clamp the mold. Then, as shown in FIG. 6B, the cap portion of the hard material is formed by the large-diameter concave portion 304 of the slide mold 20 ′ and the large-diameter concave portion 301 of the movable mold 300. A cavity K 'having a large volume is formed. Since the seal portion S ′ has already been formed at the bottom of the cavity K ′, the hard resin molten resin separately measured is injected from the second injection device 13 into the cavity K ′. The hard material is
The sprue runner 8 'is injected from the gate into the cavity K' through the second runner 6 '. By this secondary molding, the cap portion is integrally formed with the seal portion S ′.
After cooling and solidification, the movable platen 30 is opened and the molded product is taken out. Hereinafter, molding is performed in the same manner. According to the present embodiment,
Suitable for single-piece molding, and since the primary and secondary molding are performed at substantially the center of the mold, there is no uneven load applied to the mold, making it suitable for molding large-sized molded products. .

It is clear that the present invention can be implemented in various forms without being limited to the above embodiment. For example, the first and second cores of the fixed mold may be arranged in the horizontal direction, and the slide mold may be slid in the horizontal direction. It is also apparent that the device can be driven so as to be driven in an oblique direction depending on the layout of the device. Further, in the above-described embodiment, an example in which a molded product is formed from a seal portion made of a soft material and a cap made of a hard material has been described. However, a molded product formed of a flange and a packing can be formed in a similar manner. Further, in the above-described embodiment, an example in which the cavities K, K ′, k, and k ′ are formed in a circular shape has been described. However, it is obvious that the shape of the cavities is not limited to a circular shape and can be implemented.

[0023]

As described above, according to the present invention, when obtaining a molded article composed of two materials in which the first semi-molded article and the second semi-molded article are integrated, a small amount of soft material is first injected. Since a large amount of hard material is injected later, a part of the first semi-molded product having a small capacity and being solidified early is melted by a large amount of latent heat of the large amount of hard material injected later, and the first and second parts are melted. The semi-molded product can be melted and fused. That is, it is possible to obtain a molded product made of two materials having high joining strength despite being different materials of a soft material and a hard material. Also, since the primary molding is performed at a position deviated from the center position of the mold clamping device and the secondary molding is performed at the center position, a relatively large resin pressure acting during the secondary molding is applied to the mold and the mold clamping device. It works equally and has the effect of extending the service life of the mold and the mold clamping device. Furthermore, the molding cycle can be shortened because the first resin is injected from the first sprue and the second resin is injected substantially simultaneously from the second sprue. In addition, since the fixed mold and the slide mold are used, the primary and secondary molding can be performed simultaneously, and a molded article made of two materials having high dimensional accuracy can be molded. Also, automatic molding can be easily performed. According to the second aspect of the invention, when the slide mold is clamped to the fixed mold, a cavity having a relatively small volume is formed, and a relatively small cavity is combined with the cavity having a relatively small volume. Since a cavity with a large volume is formed, a soft material is injected into a cavity with a relatively small volume,
At the same time, leaving the soft material in the relatively small cavity and injecting the hard material into the relatively large cavity,
For example, a cap with a seal made of a soft material and a hard material can be obtained. Moreover, according to the present invention, when the mold is clamped, a cavity having a relatively small volume and a cavity having a relatively large volume combined with the cavity having a relatively small volume are formed. In other words, the space for the secondary molding is formed. Can be obtained simply by clamping the mold without specially securing the conventional mold, so that the structure of the mold can be simplified, and the effect of providing a mold or a molded product at low cost can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view showing a cross section of a part of a mold according to an embodiment of the present invention in an opened state.

FIG. 2 is a view showing a molding process according to the embodiment of the present invention, in which (a) is a front view showing a state in which primary molding is completed at a first position of a slide mold in a partial cross section, (B) is a front view showing a state in which the mold is opened at that position in a partial cross section.

FIG. 3 is a view showing a molding step according to the embodiment of the present invention, in which (a) shows the first and second positions of the slide mold at the second position.
FIG. 4 is a front view showing a state in which the next molding is completed as a partial cross section, and FIG. 4B is a front view showing a state in which a mold is opened at that position and a molded product is taken out, as a partial cross section.

FIG. 4 is a view showing a molding step according to the embodiment of the present invention, in which (a) is a front view showing a state in which a slide mold is slid to a first position and the mold is opened in a partial cross section. FIG. 2B is a front view showing a state in which the primary and secondary moldings are completed at that position in a partial cross section.

FIG. 5 is a view showing a molding process according to the embodiment of the present invention, in which (a) is a front view showing a state in which a mold is opened at a first position of a slide mold and a molded product is taken out in a partial cross section. FIG. 2B is a front view showing a state in which the slide mold is slid to the second position and the mold is opened in a partial cross section.
(C) is a front view showing a state in which the primary and secondary moldings have been completed at that position in a partial cross section.

FIG. 6 is a view showing another embodiment of the present invention, in which (a) is a front view showing a part of a cross section in a state where a mold is closed for primary molding, and (b) is It is a front view showing a part in section in a state where a metallic mold was closed for secondary molding.

[Explanation of symbols]

Reference Signs List 1 fixed mold 4 first core 7 second core 9 recess 20 slide mold 21 first large diameter recess 22 first small diameter recess 23 second large diameter recess 24 second small diameter recess k relatively volume Small cavity K cavity with relatively large volume S seal part C cap part P molded product

Claims (3)

(57) [Claims] 1. A molded product in which a first semi-molded product made up of a relatively small amount of a first resin and a second semi-molded product made up of a relatively large amount of a second resin are laminated and integrated. In primary molding using a fixed mold and a slide mold, the first resin is injected
In the second molding, the second resin is slid to the second molding position in a state where the first molding is held in the slide mold, and the second resin is laminated on the first molding. Injection to obtain a secondary semi-molded product
A part of the primary semi-molded product is melted and fused with resin,
What is claimed is: 1. A molding method for obtaining a molded product in which a semi-molded product and a second semi-molded product are integrated, wherein the first resin is a soft material for molding a seal such as a seal or packing; Use a hard material for forming the lid body such as a lid, a cap, a flange, etc., the primary molding is at a position deviated from the center position of the mold clamping device, and the secondary molding is substantially at the center position. A method of molding a molded article made of two materials, wherein the first resin is injected from the first sprue and the second resin is injected substantially simultaneously from the second sprue. 2. A fixed mold (1) having first and second cores (4, 7) and a concave portion (9) provided on the parting line side, and a fixed mold (1) similarly provided on the parting line side. One, two
And a slide mold (20) which is slidably provided so as to take first and second positions with respect to the fixed mold (1). When the mold is clamped to the fixed mold (1) when the slide mold (20) is at the first position, the first recess (22) of the slide mold (20) is formed. And the first core (4) of the stationary mold (1) form a cavity (k) having a relatively small volume, and the second recess (23) of the slide mold (20) and the second recess (23). Fixed mold (1)
The concave portion (9) forms a cavity (K) having a relatively large volume combined with a cavity (k) having a relatively small volume. When the slide mold (20) is at the second position, the cavity (K) is formed. When the mold is clamped with respect to the fixed mold (1), the second concave portion (24) of the slide mold (20) and the second core (7) of the fixed mold (1) have a relatively large volume. A small cavity (k) is formed, and the first recess (23) of the slide mold (20) and the fixed mold (1).
Characterized in that a cavity (K) having a relatively large volume combined with a cavity (k) having a relatively small volume is formed by the concave portion (9). . 3. The fixed mold (1) according to claim 2, wherein the recess (9) is provided substantially at the center with respect to the mold clamping device.
The core (4) and the second core (7) are provided at positions equidistant from the center, and are used for forming a molded product made of two materials.