JP3527802B2 - Mold for molding multiple articles and method for molding multiple articles using this mold - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a fixed mold and a movable mold, and a mold for molding a plurality of articles in which a plurality of cavities having different shapes, volumes and the like are provided in these molds. The present invention relates to a method for molding a plurality of products using this mold.

[0002]

2. Description of the Related Art An injection molding method for obtaining a molded product by injection-filling a cavity of a mold with a molten resin is well known in the art, and various molding products can be obtained by this molding method.
In particular, this molding method is suitable for mass production of one kind of product, for example, for containers in large quantities, and a large amount is molded by this molding method. By the way, recently, the mass production method as described above is being changed to a small quantity production of a plurality of products, for example, a molding method for molding products such as a main body and a lid and a main body and a handle. When molding the main body and the lid in this way, it is possible to mold the main body with a mold on one side and mold the lid with another mold. Therefore, it is desirable to mold two types of molded products with a single-sided mold, since problems such as complicatedness, low production efficiency, high cost, and large installation space occur.

[0003]

As described above, when two types of molded products are molded with a die having one surface, the production efficiency and the like can be increased, but the cavities are filled when the molded products have different volumes. Problems can arise because the time is different. That is, if the product is injected under the condition of obtaining a small volume product, the cavity for obtaining the product of large volume is insufficiently filled, whereas if the product is injected under the condition of obtaining a product of large volume, the cavity for obtaining the product of small volume is overfilled. Become. Therefore, attempts have been made to solve the above problem by increasing the size of the gate leading to the cavity with a large volume and decreasing the size of the gate of the cavity with a small volume.However, if the product volume difference is large, defects such as short shots and burrs will occur. However, there is a limit in the size of the gate, and it cannot be actually molded. Therefore, according to the present invention, there is a difference in shape, volume, etc. between a plurality of products, and even if the difference is large, a plurality of products can be molded with a one-sided mold, so that a plurality of molding dies can be formed. It is also an object of the present invention to provide a method for molding a plurality of products using this mold.

[0004]

In order to achieve the above object, a mold for molding a plurality of articles according to the present invention comprises a fixed mold and a movable mold, and these molds have shapes and volumes. And a plurality of cavities different from each other are provided, and a runner communicating with the plurality of cavities is provided with a switching core that slides into a plurality of positions, and the switching core takes a predetermined position. In this case, the hot sprue provided in the fixed mold is configured to communicate with a predetermined runner in cooperation with the resin that has been previously filled and solidified. The invention according to claim 2 uses the mold according to claim 1 to switch at least the switching core so that the runner is in communication with the first cavity of the plurality of cavities, and to the cavity. A first injection step of injecting and filling a molten resin to form a first molded article; and a resin which is previously filled and solidified after the first injection step with the switching core in a predetermined position. By the cooperation, the runner is switched so as to communicate with the second cavity, and the second injection step of injecting and filling the cavity with the molten resin to form the second molded article produces at least two types of molded articles. 1
When it is molded by the surface die, it is plasticized and injected each time. According to a third aspect of the present invention, by using the mold according to the first aspect, the switching core is switched so that the runner is in communication with the first cavity, which requires the most time to cool and solidify, and melts into the cavity. Resin injection
Fill and cool with pressure, while plasticizing the resin material for injection into the second cavity, which takes time next,
Next, with the switching core in a predetermined position, the switching core is switched so that the runner communicates with the second cavity in cooperation with the previously filled and solidified resin, and the molten resin is injected into the cavity. Fill and cool with pressure retention, while plasticizing the resin material to be injected next, repeating the above operation to form at least two types of molded products.
It is configured to be molded by a surface mold.

Therefore, the movable mold is clamped to the fixed mold. The switching core is the first of the plurality of cavities
The cavity is switched so that the runner communicates with, for example, the cavity that requires the most time to cool and solidify. Then, the molten resin is injected and filled. Wait for the molten resin injected into the first cavity to solidify to some extent. During this period, claim 4
In the invention described, the resin material to be injected next is plasticized. When the molten resin in the first cavity is solidified, for example, when the runner portion is solidified, the switching core is switched so that the runner communicates with another cavity in which it takes time to cool and solidify next. Then, it waits for the molten resin to be injected and filled into the cavity and solidified. During this period, similarly, in the invention according to claim 4, the resin material to be injected next is plasticized. Open the movable mold and take out the two types of molded products. While repeating the above operation, two types of molded products are molded by a mold having one surface. Alternatively, as described above, the switching cores are switched so that the runners are sequentially communicated with the plurality of cavities, injection filling is performed, and three or more types of molded products are molded by the one-sided mold.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. As shown in FIG. 1A, the mold according to this embodiment also includes a fixed mold 1 and a movable mold 10. The fixed mold 1 is provided with a known hot sprue 2. Further, the fixed mold 1 is provided with cavities for molding molded products having different shapes and volumes, such as a main body and a lid, a main body and a handle, etc. A first cavity 3 having a large volume,
Two second cavities 4 smaller than this are provided at a predetermined interval.

The movable mold 10 includes the first and second fixed molds 1.
First and second runners 11 and 12 respectively communicating with the cavities 3 and 4 are formed along the parting line. The first and second runners 11 and 12 communicate with the hot sprue 2 of the fixed mold 1 at approximately the middle portion thereof. The switching core 20 is provided in the vicinity of the communication. As shown in (b) of FIG. 1, the switching core 20 is slidably provided in a bore 21 in the movable mold 10, and the switching core 20 is a rod 23 of a drive device such as an air cylinder device 22. In (b) , it is slidably driven in the left-right direction. In the position shown in the figure, the second runner 12 is closed and when pulled to the right in the figure, the first and second runners 11, 12 both come into communication with the hot sprue 2 of the fixed mold 1. It has become. The movable mold 10 includes the first and second cavities 3, 4
The ejector rods 13 and 14 are provided in correspondence with the above. And these ejector rods 1
As is well known, the end portions of the units 3 and 14 are attached to the ejector plate 15.

Next, a molding method using the molds 1 and 10 will be described. For example, an injection machine equipped with a two-condition controller measures the resin material injected into the first cavity 3 having a large volume. Then, as shown in (b) and (c) of FIG. 1, the second runner 12 is closed by the switching core 20, and the molten resin is discharged from the nozzle N through the hot sprue 2, the first runner 11 and the gate. And is injected at a predetermined pressure set in the first cavity 3 having a large volume. After the injection is finished, the resin material to be injected into the second cavity 4 having a small volume is weighed. When the molten resin injected into the first cavity 3 is solidified, that is, when the resin in the first runner 11 is solidified, the air cylinder device 22 retracts the switching core 20 from the first and second runners 11 and 12. Then, since the first runner 11 is closed by the resin, the hot sprue 2 of the fixed mold 1 comes to communicate only with the second cavity 4 having a small volume through the second runner 12. Then, similarly, the molten resin is injected from the nozzle N into the second cavity 4 through the hot sprue 2, the second runner 12 and the gate at a predetermined pressure. The state of injection into the second cavity 4 is shown in FIG.

When the molten resin in the first and second cavities 3 and 4 is solidified, as shown in FIG. 2B, the movable mold 10 is opened and the ejector rods 13 and 14 are used to eject the first and second movable molds 10.
Stick out the two molded products J and J '. First and second molded products J,
The resin material to be injected into the first cavity 3 is weighed until J ′ is taken out and the movable mold 10 is clamped to the fixed mold 1. The subsequent molding is performed in the same manner.

According to the present embodiment, various effects can be obtained. For example, since the switching core 20 is provided in the first and second runners, the gate can be selected to have a size suitable for the first and second cavities 3 and 4, and the injection machine equipped with the two-condition controller is used. Since it is used, defects such as short shots and burrs do not occur in the molded product. Moreover, since the first cavity 3 having a large volume, which takes time to cool and solidify, is filled first, the molding efficiency can be improved. Furthermore, since the measurement is carried out in two batches and the injection is carried out, it is possible to obtain a molded product having a large overall capacity even with an injection machine having a small capacity.

In the above embodiment, it is simply assumed that the time required for cooling and solidification is longer in the first cavity 3 having a larger volume, but the time required for cooling and solidification depends on the shape of the molded product. different. Therefore, upon implementation, it is desirable to determine the injection order from the shapes and volumes of the first and second cavities 3 and 4.

FIG. 3 is a plan view schematically showing another embodiment of the runner portion similar to that shown in FIG. 1A. As shown in FIG. 3, another embodiment of the present invention is shown. According to the configuration, the first to third three cavities 3 ', 4', 5'include:
The first to third three runners 11 ', 12', 13 'communicate with each other, and these runners 11', 12 ', 13' are connected.
Meet at part 14. A slide-type switching core 20 'is provided near the merged portion 14.
Although not shown in the drawing, the hot sprue 2 faces the confluent portion 14 perpendicularly to the paper surface as in the above-described embodiment.

Therefore, as shown in FIG. 3A, the switching core 20 'is formed by, for example, an air cylinder device.
Is driven to the first position where the arcuate tip end of the arc abuts the inner peripheral surface of the portion 14, the second and third runners 1
2 ′ and 13 ′ are closed by the switching core 20 ′, and only the first runner 11 ′ communicates with the hot sprue 2. Thereby, the first cavity 3'can be filled with the molten resin. After filling, when the switching core 20 'is pulled to the second position as shown in FIG. 3B, the first runner 11' is already filled with resin and the third runner 13 'is switched. Only the second runner 12 ′ communicates with the hot sprue 2 because it is blocked by the core 20 ′. Therefore, the second cavity 4'can be similarly filled with the molten resin. Further, when it is set to the third position as shown in FIG. 3C, the first and second runners 11 ′ and 12 ′.
Are already filled with resin and only the third runner 13 ′ communicates with the hot sprue 2. Thereby, the third cavity 5'can be filled with the molten resin.

According to the above embodiment, two or three cavities 3, 4 or 3 ', 4', 5 ',
These three cavities 3, 4 or 3 ', 4',
2 or 3 runners 11 ', 1 communicating with 5'
2'and 13 'are provided, but four or more runners are provided around the switching core 20 in the same manner as in the above embodiment, and four cavities having different shapes, volumes, etc. are connected to these runners. It is also possible to provide more than one. At this time, it goes without saying that cavities having the same shape, volume, etc. may coexist. Further, according to the above-described embodiment, one cavity is connected to one runner, but one runner may be provided with a plurality of cavities having the same volume, for example. As a result, the structure of the switching core 20 can be simplified even if the number of cavities is increased. Furthermore, although the switching core 20 is of a slide type, it may be of a rotary type. In addition, in the above-mentioned molding example, an injection machine equipped with a two-condition controller measures the amount in two times. However, the amount is measured in one time and then in two times.
Alternatively, the injection can be performed in multiple times.

[0015]

As described above, according to the invention described in claim 1, the mold is provided with a plurality of cavities having different shapes, volumes and the like, and the runner communicating with the plurality of cavities. Is provided with a switching core that slides at a plurality of positions. When the switching core takes a predetermined position, a hot sprue provided on a fixed mold is provided.
Is a combination of the resin that has been previously filled and solidified,
Since it communicates with a predetermined runner, that is, the switching core is a slide type, it communicates with the runner in cooperation with the resin that has been previously filled and solidified. Can be provided. According to the invention described in claim 2 or 3, since the molding dies for a plurality of products according to claim 1 are used, even if there is a large difference in shape, volume, etc. of the molded product, short shot, burr, etc. A unique effect of the present invention is that two or more types of high quality molded products having no quality can be obtained with a die having one surface. At this time, it is plasticized for each injection process, or plasticized for the next injection while the molten resin is injected and filled in the cavity and cooled while holding pressure. Can be molded with. Therefore, a more precise molded product can be obtained. In addition, since it is plasticized each time, it is possible to obtain a molded product having a large overall capacity even with an injection machine having a small capacity. Furthermore, since it is possible to perform the measurement in proportion to the cavity and to inject at a corresponding injection pressure, it is possible to obtain a molded product of higher quality.

[Brief description of drawings]

FIG. 1 is an embodiment of a mold for molding a plurality of articles of the present invention,
It is a figure which shows the molding sequence which uses this metal mold | die, (a) is sectional drawing which shows a metal mold | die typically, (b) is a top view which shows a part of movable mold, (c) is a 1st figure. FIG. 3 is a cross-sectional view schematically showing a state in which the injection is finished in the first cavity.

FIG. 2 is a diagram showing a molding sequence using the molding die according to the present embodiment, in which (a) schematically shows a state in which the injection is finished in the first cavity and is injected in the second cavity. FIG. 4B is a sectional view showing a state in which the movable mold is opened and the molded product is taken out.

FIG. 3 is a view schematically showing a part of another embodiment of a mold for molding a plurality of articles of the present invention and showing a molding sequence using this mold, in which (a) is the first. The state where the injection is finished in the cavity of (1), the state (b) is the state where the injection is finished in the first and second cavities, and the state (c) is the first,
It is a top view which shows typically the state which has finished injection | emission into the 2nd cavity and has injected into the 3rd cavity.

[Explanation of symbols]

1 Fixed mold 2 hot sprue 3, 3'first cavity 4, 4'second cavity 5'third cavity 10 movable mold 11, 11 'First runner 12, 12 'Second runner 13 'Third runner 20, 20 'switching core

Claims (3)

(57) [Claims] 1. A fixed mold (1) and a movable mold (10), wherein these molds (1, 10) have a plurality of cavities (3, 4, 3 ') having different shapes, volumes and the like. 4 ',
5 ') is provided and the runners (11, 12, 11', 12 ', 13') communicating with these cavities (3, 4, 3 ', 4', 5 ') are A switching core (20, 20 ') that slides at a plurality of positions is provided, and when the switching core (20, 20') takes a predetermined position, the switching core (20, 20 ') is provided on a fixed mold (1). Hottosupuru (2), by cooperation with the resin being solidified is filled previously, mold multiple products, characterized in that communicating with the predetermined runner 2. The mold according to claim 1, wherein at least the switching core (20) is provided with a plurality of cavities (3,
Switching the runner (11) to communicate with the first cavity (3) in 4), and injecting and filling molten resin into the cavity (3) to mold the first molded product (J). After the first injection step and the switching core (20) after the first injection step, the switching core (20) is set at a predetermined position, and the resin that has been previously filled and solidified cooperates with the runner to the second cavity (4). The second molding (J ') is molded by switching the (12) so as to communicate with each other and injecting and filling the cavity (4) with the molten resin.
A molding method of a plurality of products, characterized in that, when at least two kinds of molded products (J, J ') are molded by a mold of one surface by an injection step, they are plasticized and injected each time. 3. The mold according to claim 1, wherein the switching core (20) is switched so that the runner (11) communicates with the first cavity (3) which requires the longest time to cool and solidify. Then, the molten resin is injected / filled into the cavity (3) and cooled under pressure retention, while the resin material for injecting into the second cavity (4), which takes time next time, is plasticized, and then the switching is performed. With the core (20) in place, the runner (12) is switched to communicate with the second cavity (4) in cooperation with the resin previously filled and solidified, and the cavity (4) is connected to the second cavity (4). Injecting and filling molten resin into 4), cooling with holding pressure, and plasticizing the resin material for the next injection during that time, repeating the above operation, at least two types of molded products with one surface of gold Characterized by molding with a mold Molding method of multiple products.