JPH0542939B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a mold used in a rotary molding system, and in particular, the present invention relates to a mold used in a rotary molding system. The present invention relates to a mold for plastic injection molding used in a molding system that continuously performs molding in a process that is repeatedly conveyed in the order of steps.

<Conventional technology> In injection molding of plastics, etc., if the injection molding machine waits for the injected resin to harden before injecting the next resin, the waiting time of the injection molding machine becomes long and the injection molding Machine usage efficiency is poor. In particular, thick, large lenses and high-precision plastic molded products require a cooling time proportional to their size.

To improve this, we prepared multiple movable molds, filled each mold with resin using an injection molding machine, moved the molds to another location, cooled them there, and then hardened them. A so-called rotary molding method has been proposed, in which the molded product is taken out and the mold with an empty cavity is returned to the injection molding machine for circulation (e.g., JP-A-61-1999).
Publication No. 89019).

In order to make injection with the injection molding machine easier, before returning the mold to the injection molding machine, the temperature is raised to a predetermined temperature using the temperature control plate of the heating device, and the temperature of the mold that comes out of the injection molding machine is raised to a predetermined temperature. For the purpose of improving the finish of the molded product, cooling may include a step of applying pressure in a press using a temperature regulating plate attached to the press.

In this case, since the mold is moved in rotary molding, it is difficult to provide a mechanism for raising and cooling the temperature inside the mold, and the temperature is increased through heat transfer and conduction using a temperature raising device or press machine outside the mold. In many cases, the temperature of the cavity inside the mold is raised and cooled while being controlled.

Conventionally, the entire mold was heated and cooled in order to heat and cool the cavity within the mold.

<Problems to be Solved by the Invention> Therefore, in order to heat up and cool the cavity part, it is necessary to heat up and cool other parts as well, which requires extra energy. The problem was that the thermal efficiency of cooling was poor.

In addition, since the cavity is located in the center of the mold, heating and cooling of the cavity is performed after heating and cooling the large volume of the other mold parts. The problem was that precise temperature control was difficult.

The present invention has been made in view of these problems, and its purpose is to provide a rotary molding machine with good thermal efficiency in heating and cooling the cavity, and rapid and precise temperature control of the cavity. The object of the present invention is to provide a mold for plastic injection molding that is possible.

<Means for Solving the Problems> In order to achieve the above object, the plastic injection mold according to the present invention includes at least a cavity piece member, and a fixed and movable template for holding the cavity piece member. , a plastic injection mold comprising a mounting member to which each of the templates is attached, each cavity piece member of the mold passing through the template and the mounting member; attached to the inside of the member via a heat insulating member, one end of each cavity piece member is exposed to the outside from the attaching member, and a temperature regulating member equipped with a heat source is detachably attached to the attaching member, The heat source is configured to contact the exposed portion of the cavity piece member to transmit heat to the cavity piece member.

Furthermore, the plastic injection mold of the present invention includes at least a cavity piece member, a fixed and movable mold plate that holds the cavity piece member, and
In a plastic injection mold comprising a mounting member to which each of the templates is attached, the heat transfer member that transfers heat to the cavity piece member has one end fixed and fixed toward the cavity piece member from the mounting member. disposed in an extended state within a movable template, and disposed within the mounting member via a heat insulating material with the other end of the heat transfer member exposed to the outside from the mounting member; Further, a heat insulating member is disposed between the mounting member and the template, and a temperature regulating member provided with a heat source is brought into contact with the exposed end of the heat transfer member to transfer heat from the heat source to the heat transfer member. The transmission is configured to be transmitted to the cavity piece member via the member.

<Example> Hereinafter, an example of a mold according to the present invention will be described based on the drawings.

A cross-sectional view of the mold according to the first embodiment of the present invention is shown in FIG.
As shown in the figure.

In the figure, 1 is a fixed-side mounting plate, and 2 is a fixed-side mold plate, which serves as a fixed-side piece holding member that holds the fixed-side piece member 6 fixedly. Reference numeral 3 denotes a movable side mold plate, which serves as a movable side piece holding member for movably holding the movable side piece member 7. 4 is a movable side receiving plate, 5 is a movable side mounting member, 6
is a fixed side cavity piece member, 7 is a movable side cavity piece member, 8a and 8b are heat insulating materials, 9 is a heat transfer member,
10 is a cavity, 11 is a fixed side temperature control member,
12 is a movable temperature adjusting member. Reference numeral 13 denotes a hole for housing a heat source such as a heater when the temperature adjusting members 11 and 12 are used as a mold temperature raising device, and when the temperature adjusting members 11 and 12 are attached to a press machine etc. When used to cool a mold, it is a hole for flowing a coolant. 14
is a heat insulating member.

In this embodiment, a heat insulating member 8a is provided between the fixed side mounting member 1 and the fixed side piece holding member 2 to make them thermally independent, and the movable side piece holding member 3 and the movable side receiving plate 4 and a heat insulating member 8a between
are provided, and they are thermally independent. Therefore, the cavity piece members 6, 7, together with the piece holding members 2, 3, are thermally independent from other parts of the mold 21.

Furthermore, a heat transfer member 9 of a predetermined diameter is inserted into the fixed side piece holding member 2 from the fixed side mounting member 1 side, and one end of the heat transfer member 9 is molded with the end face of the mounting member 1 flush with the surface. 21 is exposed to the outside. A heat insulating member 8b is disposed around the heat transfer member 9 to prevent the heat transmitted through the heat transfer member 9 from escaping into the mounting member 1. In the movable side portion of the mold 21, the heat transfer member 9 is inserted into the movable piece holding member 3 from the movable side mounting member 5 in the same manner as described above. The material, number, spacing, etc. of the heat transfer member 9 are determined through experiments and computer simulations in order to achieve the desired design goals, such as heating up the cavity 10, thermal efficiency and speed of cooling, and precise temperature control. It is determined by Piece holding member 3 of heat transfer member 9
The same applies to the insertion depth. Note that the heat transfer member 9
The material is one that conducts heat quickly,
It is preferable that the thermal conductivity is 0.3 cal/cm·sec·°C or more. As the material of the heat transfer member 9, copper alloy, pure copper, noble metal, etc. can be used.

Next, the surfaces of the temperature adjusting members 11 and 12 that come into contact with the mounting members 1 and 5 are coated with a heat insulating member 14 . However, the heat insulating member 14 is not disposed in the portion 15 that is the position of the heat transfer member 9 when in contact with the heat transfer member 9, and therefore heat is transferred only through this portion 15, that is, to the temperature adjusting members 11 and 12. Heat can be transferred only between the heat member 9 and the heat member 9.

Note that the piece holding members 2 and 3, the mounting members 1 and 5, and the receiving plate 4 do not necessarily need to be made of the same material.

When heating the mold of this embodiment having the above configuration, the temperature adjusting members 11 and 1 are
2 are brought into contact with the mounting members 1 and 5, respectively. Then, the temperature of the temperature adjusting members 11 and 12 is raised by a heat source such as a heater built into the hole 13. Then, the heat is transferred to the portion 1 where the heat insulating member 14 is not provided.
5 to the heat transfer member 9, and is quickly conducted inside the heat transfer member 9, heating the piece holding members 2 and 3, and heating the cavity 10 (the same applies in the case of cooling).
However, the direction of heat movement is opposite).

At this time, the pieces holding members 2 and 3 and the mounting member 1 and the receiving plate 4 are thermally isolated from each other by the heat insulating member 8a, and the mounting members 1 and 4 of the heat transfer member 9 are thermally independent.
5 and the passing portion inside the receiving plate 4 are covered with a heat insulating member 8b, so the heat of the temperature adjusting members 11 and 12 moves only to the piece holding members 2 and 3 through the heat transfer member 9, and the heat transfer member 9 Since it moves through the piece, it quickly moves to the piece holding members 2 and 3. Therefore, the thermal efficiency for raising the temperature is improved, and the heating time can be shortened and the temperature can be precisely controlled. The same applies to cooling.

Furthermore, since a predetermined number of heat transfer members 9 are provided, even if the heat transfer member 9 has low strength, the strength of the mounting members 1, 5, the receiving plate 4, etc. , 4, etc. can be maintained.

Although not implemented in this embodiment, the contact portions between the heat transfer member 9 and the piece holding members 2 and 3 are formed by, for example, cutting a male thread in the heat transfer member 9 and threading a corresponding thread on the piece holding members 2 and 3. It is also possible to increase the contact area between them and increase the amount of heat transfer by providing unevenness between the contact surfaces and closely fitting them, such as by cutting female threads for close fitting and screwing them together.

Next, FIG. 2 shows a sectional view of a mold according to a second embodiment of the present invention.

In the figure, 1 is a fixed-side mounting member, 2 is a fixed-side mold plate, 3 is a movable-side mold plate, 4 is a movable-side receiving plate, and 5
6 is a movable side mounting member, 6 is a fixed side cavity piece member, 7 is a movable side cavity piece member, 23 is a heat insulating member, 24 is a fixed side temperature adjusting member, and 25 is a movable side temperature adjusting member. Temperature control member 2 shown in FIG.
4 and 25 are used to raise the temperature of the mold 22, and a heat source for a heater 26 is embedded in the central protrusion. When cooling the mold in a press machine, the temperature control member 2 shown in Fig. 2 is used.
4 and 25, a temperature adjusting member (not shown) is used in which the central protrusion is provided with a hole through which the refrigerant flows.

In this embodiment, the fixed side cavity piece member 6 extends to the fixed side mounting member 1 and further reaches the outer surface (upper surface) of the fixed side mounting member 1, and the end surface thereof extends to the outer surface of the fixed side mounting member 1. It is flush with the surface. The fixed side cavity piece member 6 is provided with a calyx portion 27, and when the calyx portion 27 is sandwiched between the fixed side mounting member 1 and the template 2, the cavity piece member 6 can be moved upward or downward. It is designed to prevent it from shifting.

The same applies to the movable cavity piece member 7, which extends from the movable side receiving plate 4 to the movable side mounting member 5.
It further reaches the outer surface (lower surface) of the movable attachment member 5, and its end surface is flush with the outer surface of the movable attachment member 5. Further, a calyx portion 28 is provided, and the calyx portion 28 is sandwiched between the movable mold plate 3 and the receiving plate 4 to prevent the cavity piece member 6 from shifting upward or downward. It's summery.

A heat insulating member 23 is installed on the contact surfaces of the fixed side and movable side cavity piece members 6 and 7 with other parts of the mold 22, respectively, and the cavity piece members 6 and 7 are placed in contact with other parts of the mold 22. It is thermally independent from .

The material, cross-sectional area, etc. of bridge members 6 and 7 are based on cavity 1.
Experiments, computer simulations, etc. are used to ensure that desired design goals such as zero temperature rise, thermal efficiency and speed of cooling, and precise temperature control are achieved. The material of the bridge members 6 and 7 is preferably one that conducts heat quickly, and has a high thermal conductivity.
It is preferable that it is 0.3 cal/cm·sec·°C or more.
Copper alloy, pure copper, noble metal, etc. can be used as the material for the bridge members 6 and 7.

Each of the temperature adjusting members 24 and 25 has a protruding portion 29 having the same cross-sectional shape as the bridge members 6 and 7, corresponding to the portion where the bridge members 6 and 7 are exposed on the outer surface of the mounting members 1 and 5. ,30,
A predetermined number of heaters 26 are embedded in the protruding portions 29 and 30 as described above.

When heating the mold of this embodiment having the above configuration, move the temperature adjustment members 24 and 25,
The end surfaces of the protruding portions 29 and 30 are joined to the exposed portions of the mounting members 1 and 5 of the cavity piece members 6 and 7, respectively. Then, the heat of the heater 26 is transmitted to the cavity piece members 6, 7, and the piece members 6, 7
The heat is conducted through the inside of the cavity and reaches the cavity 10, where the cavity 10 is heated.

At this time, the protruding portions 2 of the temperature adjustment members 24 and 25
The end faces of 9 and 30 are the mounting members 1 and 7 of the bridge members 6 and 7, respectively.
Since the heater 26 only contacts the exposed part from the outer surface, all of the heat from the heater 26 is transmitted to the cavity piece members 6 and 7, improving the thermal efficiency for temperature raising, shortening the heating time, and making it possible to Temperature control becomes possible.

The same applies to mold cooling, and when the end face of the protruding part of the temperature adjustment member cooled by the refrigerant is joined to the exposed part of the mounting members 1 and 5 of the cavity piece members 6 and 7, the cavity 10 The heat is conducted through the bridge members 6 and 7 and transferred to the temperature adjustment member, but since the only parts that are cooled by the temperature adjustment member are the bridge members 6 and 7, the thermal efficiency for cooling is improved, and the cooling This makes it possible to shorten the time and precisely control the temperature during cooling.

In addition, in this embodiment, a heat insulating member is laid on the contact surface of the bridge members 6 and 7 with other parts of the mold 22, but the bridge members 6 and 7 have a higher thermal conductivity than other mold parts. If the cavity piece members 6 and 7 are made of a material with high heat resistance, even if the heat insulating member 23 is not provided, more heat will be transferred to the cavity piece members 6 and 7. The cooling speed becomes faster, and the same effects as in this embodiment can be obtained.

Note that the heat insulating member of the present invention includes ceramics,
Possible materials include Bakelite, asbestos, and polymeric plastic molding materials.

<Effects of the Invention> The present invention has been described in detail above, and has been devised to efficiently transmit heat from the temperature adjusting member to the cavity piece member. That is, each cavity piece member of the mold is configured to pass through the mold plate and the mounting member, and the cavity piece member is attached to the inner side of the mold plate and the mounting member via a heat insulating member, and the cavity piece member One end of the bridge member is exposed to the outside from the mounting member, and the heat source of the temperature adjustment member is brought into contact therewith, or the heat transfer member is extended and placed within the cavity bridge member via a heat insulating member. Therefore, the heat transfer efficiency from the heat source to the cavity piece member via the heat transfer member can be maintained at a high level, and precise temperature control can be performed.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the invention, and FIG. 2 is a sectional view showing a second embodiment of the invention. 1... Fixed side mounting member, 2... Fixed side piece holding member (fixed side template), 3... Movable side piece holding member (movable side template), 4... Movable side receiving plate, 5... Movable Side mounting member, 6...Fixed side cavity piece member, 7
...Movable side cavity piece member, 8a, 8b, 1
4, 23... heat insulation member, 9... heat transfer member, 10...
...Cavity, 11, 24... Fixed side temperature adjustment member, 12, 25... Movable side temperature adjustment member, 13...
...Built-in hole of heater etc. or refrigerant flow path hole, 15...
. . . Portion where no heat insulating member is provided, 21 . . . sectional view of the mold of the first embodiment, 22 . . . sectional view of the mold of the second embodiment, 26 .. heater, 29, 30 .

Claims (1)

[Scope of Claims] 1. At least a cavity piece member, a fixed and movable template for holding the cavity piece member,
In a plastic injection mold comprising a mounting member to which each of the templates is attached, each cavity piece member of the mold passes through the template and the mounting member, and the mold plate and the mounting member are attached to each other. The cavity piece member is attached to the inside through a heat insulating member, and one end of each cavity piece member is exposed to the outside from the attaching member, and a temperature regulating member equipped with a heat source is detachably attached to the attaching member, A mold for plastic injection molding, characterized in that a heat source is configured to contact an exposed portion of the cavity piece member to transmit heat to the cavity piece member. 2 at least a cavity piece member, a fixed and movable template that holds the cavity piece member;
In a plastic injection mold comprising a mounting member to which each of the templates is attached, the heat transfer member that transfers heat to the cavity piece member has one end thereof fixed and fixed toward the cavity piece member from the mounting member. disposed in an extended state within a movable template, and disposed within the mounting member via a heat insulating member with the other end of the heat transfer member exposed to the outside from the mounting member; Furthermore, a heat insulating member is disposed between the mounting member and the template, and a temperature regulating member provided with a heat source is brought into contact with an exposed end of the heat transfer member to transfer heat from the heat source to the heat transfer member. A mold for plastic injection molding, characterized in that the mold is configured to transmit information to the cavity piece member through a member.