JPH10264213A - Injection mold and injection molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an injection mold for stably molding a molding without warp with a relatively simple structure by providing a temperature sensor at a slide insert. SOLUTION: A fixed side template 2 and core block 3 are separately temperature regulated by using two mold thermoregulators A, B, molten resin is cast in a cavity 15 by a nozzle of an injection molding machine via a sprue 16 in the state that a mold is clamped, and molding is started. In the case of removing a molding via a cooling step, a slide insert 6 is slid at the time of opening the mold, and released from a side of a box-shaped molding. Thereafter, an ejector plate 23 is moved, and the molding is ejected by an ejector pin 22. Temperatures of the insert 6 and block 3 monitored by temperature sensors 11, 19 are varied during one cycle, and gradually become stable state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection mold having a slide insert forming a cavity for molding a molded product, and an injection molding method using the same.

[0002]

2. Description of the Related Art There are many molded products manufactured by an injection molding method, which are not allowed to have a draft due to their structure, or have a shape in which a hole or a boss is partially formed on a side surface of the molded product. .
As a conventional technique of a mold for producing such a molded product, "injection mold" (published by Nikkan Kogyo Shimbun, Junichiro Shiraishi, published on December 10, 1976, 4th edition) is generally known. ing.

This molding die is for molding a molded product having an undercut, and includes a core block for molding an inner portion of the molded product, a side portion, a hole, and a boss of the molded product having no draft. When a molded product is taken out, it consists of a slide nest forming a part consisting of an undercut such as an undercut, a slide nest forming a part consisting of an angular pin for moving the slide nest, and an angular pin for moving the slide nest. The mold is opened and closed to release the slide insert from the core block.

[0004]

However, in the above-mentioned prior art injection mold, since a slide insert slides, it is difficult to pass a temperature-regulated liquid through the slide insert. Due to this difficulty, when the temperature of the slide insert is not adjusted, a temperature difference occurs between the core block forming the inside of the molded product and the slide insert, and when the molded product is taken out in this state, the molded product is removed. There is a problem that warpage occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention according to claim 1 or 2 is to form a molded product stably without warping with a relatively simple structure. It is to provide an injection mold that can be used. An object of the invention according to claim 3 is to provide an injection molding method capable of stably forming a warped-free molded product using the above-mentioned injection mold.

[0006]

According to a first aspect of the present invention, there is provided an injection molding die having a slide insert forming a cavity for molding a molded product. The temperature sensor is provided on the child. The invention according to claim 2 includes a fixed-side mold plate capable of adjusting the temperature, a movable-side mold plate facing the fixed-side mold plate,
A core block provided on the movable side mold plate so as to form the inner side surface of the molded product, and a core block provided so as to be able to adjust the temperature, and forming the external side surface of the molded product and moving forward and backward with respect to the core block, and In the injection molding die consisting of a slide insert provided on the movable mold plate so as to be in close contact with the fixed mold plate during mold clamping, the slide insert is
A mold member for forming the external side surface of the molded article, a sliding member in contact with the movable side mold plate, and a heat insulating member interposed between the sliding member and the mold member, and the mold member includes a temperature sensor. It is characterized by having. The invention according to claim 3 is based on claim 2
The injection molding die described above and two mold temperature controllers are used to make the temperature of the slide insert and the core block at the time of removing the molded product substantially the same.

According to the first aspect of the present invention, the temperature of the slide insert itself, which changes due to the external thermal effect of the slide insert, is checked. According to the invention according to claim 2, at the time of mold clamping, the temperature of the fixed side template is adjusted while the slide insert is in close contact with the fixed side template, so that the heat of the fixed side template is applied to the slide insert. Convey. Further, since the mold member of the slide insert is in contact with the movable mold plate via the heat insulating member and the sliding member, it is not thermally affected by the movable mold plate. According to the third aspect of the present invention, the slide insert and the core block are separately provided by the two mold temperature controllers by using the injection mold and the two mold temperature controllers. Molding was started with the temperature controlled, and when the monitored value from the temperature sensor became stable, the temperature of the slide insert and the core block of the mold were adjusted so that the temperatures of the slide insert and the core block when removing the molded product were almost the same. Change the settings as appropriate.

[0008]

1 to 4 show a first embodiment of the present invention. FIG. 1 is a front sectional view of an injection mold, FIG. 2 is a side sectional view near a slide insert, and FIG. FIG. 4 is a side view of the plate, and FIG. 4 is a plan view of the slide plate. The molded product according to the first embodiment of the present invention is a box-shaped molded product having no slope and having mirror surfaces on four peripheral surfaces.

In FIG. 1, a fixed mold plate 2 forming the upper surface of a box-shaped molded product is attached to a fixed attachment plate 1. Further, a sprue 16 for filling the resin is formed by connecting the fixed side mounting plate 1 and the fixed side mold plate 2 to each other. Further, a temperature control hole 17 is formed in the vicinity of the cavity 15 of the fixed side mold plate 2 and connected to a mold temperature controller A (not shown) so that the temperature control liquid circulates. . Further, angular pins 13 for driving the slide insert 6 are erected at four positions on the fixed side mold plate 2, and a slide backup 14 for determining a stop position of the slide insert 6 is fixed. (Two members in the direction perpendicular to the paper surface are not shown).

The slide insert 6 includes a mold member 7 provided with a molding surface 7a forming an external side surface of a box-shaped molded product, a heat insulating plate 8 which is a heat insulating member for blocking heat from the mold member 7, and a left-right direction. A sliding plate 9 which is a sliding member slidable in
As shown in FIG. 2, the mold member 7, the heat insulating plate 8 and the slide plate 9 are integrally fixed by bolts 10. A flange 9a is projected from the slide plate 9, and the flange 9a is slidably held between the guide plate 12 and the movable mold plate 4. The slide plate 9 has a flange 9a as shown in FIGS.
Bolt holes 9b are drilled at various locations.

As shown in FIG. 1, a temperature sensor 11 is embedded inside the mold member 7 at a position 2 mm away from the contact surface 7b with the fixed mold plate 2. The temperature sensor 11 is connected to a control unit of the mold temperature controller A (not shown) and transmits a temperature signal of the slide insert 6. Also, the inclined hole 7c of the mold member 7
The sliding pin 6 is driven in the sliding direction along the inclination angle of the angular pin 13 by the opening / closing operation of the injection molding die. You. Incidentally, in FIG.
Although only two locations are shown, two locations are also provided in the direction perpendicular to the paper surface, and the outer surface of the box-shaped molded product is formed by a total of four slide inserts 6. FIG. 1 shows a closed state of the injection molding die. The stationary mold plate 2 and the slide insert 6 are in close contact with each other at a contact surface 7b so that heat conduction is easily performed. I have.

A core block 3 having a flange 3a projecting therefrom and forming the inner side surface of the box-shaped molded product is fixed by sandwiching the flange 3a between the movable mold plate 4 and the movable receiving plate 5. I have. The fixed side mold plate 2, the slide insert 6 and the core block 3 form a cavity 15. A temperature control hole 18 is formed in the vicinity of the cavity 15 of the core block 3 and connected to a separate mold temperature controller B (not shown) independent of the temperature control hole 17 of the fixed mold plate 2. The temperature control liquid is configured to circulate. In addition, core block 3 includes:
A temperature sensor 19 is embedded and connected to a control unit of a mold temperature controller B (not shown) to transmit a temperature signal of the core block 3. The movable-side receiving plate 5 is fixed to a movable-side mounting plate 21 via a spacer block 20. An ejector plate 23 to which an ejector pin 22 is fixed is provided between the two spacer blocks 20, and the ejector pin 22 is inserted through the movable receiving plate 5 and the core block 3 to discharge a box-shaped molded product. I can do it.

Next, a method of injection-molding a box-shaped molded product using the injection mold having the above configuration will be described. First, the temperature of the fixed mold plate 2 and the core block 3 is separately adjusted using two mold temperature controllers A and B, not shown. Next, as shown in FIG. 1, in the clamped state, the molten resin is injected into the cavity 15 via the sprue 16 from a nozzle of an injection molding machine (not shown) to start molding. When the molded product is taken out through the cooling step, the slide insert 6 slides with the opening of the mold, and the side surface (outside surface) of the box-shaped molded product is removed.
Break away from Thereafter, the ejector plate 23 moves, and the ejector pins 22 project the box-shaped molded product. When a series of steps of the molding method are continuously performed, the temperatures of the slide insert 6 and the core block 3 monitored by the temperature sensors 11 and 19 fluctuate during one molding cycle, but gradually become stable. Calm down.

At this time, the temperature difference between the slide insert 6 and the core block 3 when removing the box-shaped molded product is removed.
Change the settings of the mold temperature controllers A and B. Core block 3
Is controlled by the temperature control liquid passing through the temperature control hole 18, and the slide insert 6 is hardly affected by the temperature from the movable mold plate 4 by the effect of the heat insulating plate 8, Since it is in close contact with the template 2, the temperature is controlled by the temperature control liquid flowing through the temperature control hole 17 of the fixed-side template 2. Further, the molding operation is continued, and the molded product is taken out in a state where the temperature of the slide insert 6 and the core block 3 at the time of taking out are substantially the same. Even if the box-shaped molded product is taken out in this state, warpage may occur when it is cooled to room temperature, so in that case, check the state of the warp,
Adjust the settings of the mold temperature controllers A and B.

According to the first embodiment of the present invention, since the temperature of the slide insert, which is difficult to control the temperature, can be easily adjusted by using the injection mold having a relatively simple structure, the box shape is stable and free from warpage. A molded article can be formed.

In the first embodiment of the present invention, a box-shaped molded product having mirror surfaces on four peripheral surfaces has been described. However, the number of slide inserts may be increased or decreased according to the number of surfaces. Embodiment 1 of the present invention can be applied to a box-shaped molded product.

[0017]

Second Embodiment FIG. 5 shows a second embodiment of the present invention, and is a side sectional view near a slide insert. The second embodiment of the present invention is different from the first embodiment only in the structure of the slide insert, and other parts are the same as those of the first embodiment of the present invention.

In the first embodiment of the invention, the injection mold is
In the clamped state, the slide insert 6 and the fixed mold plate 2 were in close contact with each other, but in the second embodiment of the present invention, as shown in FIG. 7b was slightly shaved by 0.02 mm, and a silicon thin film 31 having a high thermal conductivity and a thickness of 0.02 mm was attached to that portion. Thereby, the fixed side mold plate 2 and the silicon thin film 31 of the slide insert 30 are brought into close contact with each other at the time of mold clamping. Other configurations are the same as those of the first embodiment.

The injection molding method for a box-shaped molded product using the injection mold having the above configuration according to the second embodiment of the present invention is the same as that of the first embodiment of the present invention.

According to the second embodiment of the present invention, in addition to the same effects as in the first embodiment of the present invention, in the first embodiment of the present invention, the slide insert 6 and the fixed-side mold plate 2 come into close contact with each other. Therefore, the slide insert 6 may be pressed and slightly inclined by the mold clamping force at the time of molding. However, in the second embodiment of the present invention, the slide insert 6 is interposed between the slide insert 30 and the fixed side mold plate 2. Since the silicon thin film 31 deforms, the slide insert 30 does not tilt.

In the second embodiment of the present invention, the modification shown in the first embodiment of the present invention can be similarly applied.

[0022]

Third Embodiment FIGS. 6 and 7 show a third embodiment of the present invention. FIG. 6 is a side sectional view of a slide insert, and FIG. 7 is a plan view of a slide plate. Embodiment 3 of the present invention
Only the slide plate of the slide insert is different, and the other parts are the same as those of the first embodiment of the present invention.

In FIG. 6, a slide insert 40 of an injection molding die is constituted by integrating a mold member 7, a heat insulating plate 8 and a slide plate 41 with bolts 10. As shown in FIG. 7, the slide plate 41 is formed by adding nine lightening holes 42 to the slide plate 9 of the first embodiment of the present invention. Other configurations are the same as those of the first embodiment.

The injection molding method of a box-shaped molded product using the injection mold having the above-mentioned configuration according to the third embodiment of the present invention is the same as that of the first embodiment of the present invention.

According to the third embodiment of the present invention, in addition to the same effects as those of the first embodiment of the present invention, the contact area between the heat insulating plate 8 and the slide plate 41 is reduced as compared with the first embodiment of the present invention. Due to the narrowing, the influence of the temperature of the movable mold plate 4 can be further suppressed, and the temperature control of the slide insert 40 due to the contact with the fixed mold plate 2 is stabilized.

In the third embodiment of the present invention, the modification shown in the first embodiment of the present invention can be similarly applied.

The invention of the present application includes the creation of the following technical idea. (1) The injection mold according to claim 2, wherein a soft thin film such as silicon is interposed between the slide insert and the fixed mold plate. In addition to the effect of the second aspect, since a soft thin film member such as silicon is interposed between the slide insert and the fixed side mold plate, the slide insert does not tilt due to the mold clamping force. (2) The injection molding die according to (2), wherein a plurality of lightening holes are provided in the slide plate of the slide insert. In addition to the effect of the second aspect, by providing a plurality of lightening holes in the slide plate of the slide insert, the influence of the temperature of the movable mold plate can be further suppressed, and the contact with the fixed mold plate can be reduced. The temperature control of the slide insert is stabilized.

[0028]

According to the first aspect of the present invention, since the temperature of the slide insert forming the cavity can be measured and the temperature can be controlled, the sled can be stably formed with a relatively simple configuration. A molded article free from defects can be obtained. Claim 2
According to the invention, the slide insert is in close contact with the fixed mold plate when the mold is clamped, so that the temperature of the slide insert can be adjusted by adjusting the temperature of the fixed mold plate. Further, since the slide insert has the heat insulating member, the influence of the temperature of the movable mold plate in contact with the slide insert is small. Therefore, it is possible to stably obtain a molded product without warpage. According to the invention according to claim 3, molding is started in a state where the slide insert and the core block are separately temperature-controlled by the two mold temperature controllers, and when the monitored value by the temperature sensor is stabilized, The settings of the temperature controllers of the slide insert and the core block are appropriately changed so that the temperatures of the slide insert and the core block at the time of removing the molded product are substantially the same. Thus, by eliminating the temperature difference between the inside and the outside when removing the molded product, the warpage of the molded product can be suppressed.

[Brief description of the drawings]

FIG. 1 is a front sectional view of an injection mold according to Embodiment 1 of the present invention.

FIG. 2 is a side sectional view of the vicinity of a slide insert according to the first embodiment of the invention;

FIG. 3 is a side view of the slide plate according to the first embodiment of the present invention.

FIG. 4 is a plan view of the slide plate according to the first embodiment of the present invention.

FIG. 5 is a side sectional view of the vicinity of a slide insert according to a second embodiment of the invention.

FIG. 6 is a side sectional view of a slide insert according to a third embodiment of the present invention.

FIG. 7 is a plan view of a slide plate according to Embodiment 3 of the present invention.

[Explanation of symbols]

 6 Slide insert 11 Temperature sensor 15 Cavity

Claims (3)

[Claims] 1. An injection molding die having a slide insert forming a cavity for molding a molded product, wherein the slide insert has a temperature sensor. 2. A temperature controllable fixed-side template, a movable-side template facing the fixed-side template, and a movable-side template provided on the movable-side template to form an inner surface of a molded product. An adjustable core block and a movable mold plate are provided on the movable mold plate so as to form the exterior side surface of the molded product and to advance and retreat with respect to the core block, and to be in close contact with the fixed mold plate during mold clamping. In the injection molding die comprising a slide insert, the slide insert is formed of a mold member for forming an external side surface of a molded product, a sliding member in contact with a movable mold plate, and a sliding member and a mold member. An injection molding die comprising a heat insulating member interposed therebetween, wherein the die member is provided with a temperature sensor. 3. The temperature of the slide insert and the core block at the time of removal of a molded product is made substantially the same by using the injection molding die according to claim 2 and two mold temperature controllers. Injection molding method.