JPH08318548A - Injection mold equipment - Google Patents

Abstract

(57) [Summary] [Purpose] The lower mold is divided so that the part where the die-cutting angle with respect to the upper mold is less than 10 ° is opened first so that the surface of the bumper is scratched. While preventing the smooth mold opening, it also expands the freedom of bumper design. [Structure] A bumper B is molded by injecting a resin material into a cavity 4 formed by an upper mold 2 for molding the front side of the bumper and a lower mold 3 for molding the rear side of the bumper. The lower die has a die-cutting angle of less than 10 ° relative to the upper die when the die is opened.
Molding die 11 and the die cutting angle with respect to the upper die when opening the die are 10 °
It is divided into the above-mentioned second mold 12. In the mold opening direction of the first molding die with respect to the second molding die, with the bumper being sandwiched between the upper mold and the second molding die when the mold is opened between the first molding die and the elevating and lowering table 15. Is provided and a stopper 21 is provided for restricting the movement of the first molding die when the descending amount of the first molding die reaches a predetermined amount.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an injection molding die apparatus for injection molding a plate-shaped resin molded article.

[0002]

2. Description of the Related Art Conventionally, as a mold apparatus for injection molding for molding a plate-shaped resin molded article such as a bumper for an automobile, for example, as disclosed in Japanese Utility Model Publication No. 5-4980, the molded article surface side A resin molding material is injected into a cavity formed by a front surface molding die for molding and a back surface molding die for molding the back surface side of the molded product to mold a plate-shaped resin molded product. Are known. Then, the back mold together with the resin mold is opened with respect to the front mold to open the cavity, and the resin mold is taken out from the back mold.

[0003]

By the way, when the back mold is opened, the back mold has a large number of irregularities and the like as compared with the front mold because of the structural reasons. Although the mold and the back surface of the resin molded product are difficult to peel off, the surface molded mold and the front surface of the resin molded product are easily peeled off. It is designed to move in the mold opening direction. However, if the die-cutting angle of the back surface molding die with respect to the front surface molding die is less than a predetermined value (for example, an inclination of 10 °),
At the time of opening the back surface molding die, the resin molded product is easily bent in the mold opening direction between the front surface molding die and the back surface molding die, and the surface of the resin molded product is rubbed against the front surface molding die due to the unreasonable opening of the mold and the scratches may occur. It is impossible to open the mold smoothly. Further, when molding a resin molded product with an injection molding die device, a die-cutting angle for the surface molding die needs to be a predetermined value or more in order to prevent scratches on the surface, which limits the design of the resin molded product. Will be things.

The present invention has been made in view of the above points, and an object of the present invention is to form a back surface molding die in such a manner that a portion where a die cutting angle with respect to the front surface molding die is less than a predetermined value when the die is opened. By dividing so as to open the resin molded product, it is possible to prevent the surface of the resin molded product from being scratched while allowing smooth mold opening, and to expand the degree of freedom in designing the resin molded product.

[0005]

In order to achieve the above-mentioned object, the means for solving the problems according to the invention of claim 1 is to form a surface molding die for molding the front surface side of a molded product and a back surface side of the molded product. It is premised on an injection molding die device in which a resin raw material is injected into a cavity formed by a back molding die for molding a plate-shaped resin molded article. Then, the back molding die has a first molding die whose die cutting angle with respect to the front surface molding die is less than a predetermined value when the die is opened, and a first die whose die cutting angle with respect to the surface molding die is more than a predetermined value when the die is opened. Two
Divide into molds. Further, a first mold for the second mold is held between the first mold and the second mold with the resin molded product held between the surface mold and the second mold when the mold is opened. A stopper is provided to allow the mold to move in the mold opening direction and to restrict the movement of the first mold when the amount of movement of the first mold reaches a predetermined amount.

The means for solving the problems according to the invention of claim 2 is as follows.
The back surface molding die of the invention according to claim 1 is specified, and the first molding die and the second molding die are separated with a die cutting angle of 10 ° with respect to the front surface molding die.
It is configured to be divided into a molding die.

[0007]

According to the above-mentioned structure, according to the first aspect of the present invention,
With the stopper, the first molding die precedes the second molding die in the mold opening direction while the resin molding is held between the front molding die and the second molding die when the back molding die is opened. When the moving amount of the first molding die reaches a predetermined amount, the preceding movement of the first molding die is restricted, and therefore, the preceding movement of the first molding die in the mold opening direction. Thus, a gap is formed between the first mold and the back surface of the resin molded product. Therefore, when the mold is opened from the state in which the gap is formed, the corresponding portion of the resin molded product corresponding to the first molding die is peeled from the surface molding die and escapes in the gap to the first molding die side. Further, the surface of the resin molded product is not rubbed, and the mold is smoothly opened without damaging the surface of the resin molded product. Moreover, in order to prevent the surface from being scratched, it is not necessary to set the die-cutting angle with respect to the surface forming die to a predetermined value or more, and the degree of freedom in designing the resin molded product is expanded.

According to the second aspect of the invention, the back mold is
Since the mold is divided into the first mold and the second mold at a die cutting angle of 10 ° with respect to the surface forming die, even if the die forming angle with respect to the surface forming die is less than 10 °, the first forming die is opened. By moving the mold in advance in the mold opening direction, it is possible to prevent the surface of the resin molded product from being scratched, and the degree of freedom in design is effectively expanded.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an injection molding die apparatus according to an embodiment of the present invention used for injection molding a plate-like object such as a resin bumper of an automobile. The injection molding die apparatus 1 is shown in FIG. Is a fixed upper mold 2 as a surface molding mold for molding the bumper front surface, and a back surface molding mold for vertically moving with respect to the upper mold 2 for molding the back surface of the bumper. It has a movable lower mold 3. That is, the lower mold 3 is movable up and down with respect to the upper mold 2 in the mold opening direction or the mold closing direction.

A sprue (not shown) is provided at a predetermined position of the upper die 2 so as to extend in the vertical direction, and the sprue is connected to a nozzle of an injection molding machine (not shown) through a passage (not shown). A plastic melt molding material (not shown) such as polypropylene, which is injection-pressed from a nozzle of the injection molding machine, is introduced into the sprue through the passage. The plastic melt molding material introduced into the sprue is injected and filled (injected) into the cavity 4 formed between the mating surfaces of the upper mold 2 and the lower mold 3. In this case, when the lower mold 3 is opened, the lower mold 3 has many protrusions such as ribs and bosses (not shown) in its structure as compared with the upper mold 2. And the back surface Bb of the bumper B are hard to peel off, but the upper mold 2 and the front surface Ba of the bumper B are easily peeled off. The bumper B is peeled off from the upper mold 2 at the time of mold opening and is opened together with the lower mold 3. It is designed to descend in the direction.

Further, as shown in FIG. 2, the lower mold 3 is
When the mold is opened, that is, when the lower mold 3 is lowered, the first mold 11 has a mold cutting angle α of less than 10 ° with respect to the upper mold 2, and when the lower mold 3 is lowered, the mold cutting angle β with respect to the upper mold 2 is 10 ° or more. It is divided so that it can come into contact with and separate from the second mold 12. Further, the lower mold 3 is a base fixed to the lifting drive means (not shown) and the first molding mold 11 fixed to the lower side of the first molding mold 11 via the struts 13 and 13. The platform 14 is provided between the first molding die 11 and the base 14 and can be vertically moved between the two 11, 14
5, the upper end is fixed to the second molding die 12 and the lower end is fixed to the elevating and lowering pedestal 15, respectively, and the penetrating pin 16 penetrating the first molding die 11 slidably in the vertical direction, and the lower end is the elevating platform. A contact pin 17 that is fixed to 15 and has its upper end abutting the lower surface of the first mold 11 and penetrating the first mold 11 slidably in the vertical direction;
A lower end of which is fixed to each of the bases 14 and which penetrates the elevating and moving base 15 in a vertically slidable manner.
The support pin 18 and the upper end are on the lower surface of the first mold 11,
A large-diameter large-diameter portion 1 having lower ends fixed to the base 14 and penetrating through the elevating / moving base 15 slidably in the vertical direction.
Second support pin 19 having 9a and a small diameter portion 19b
And, while being wound around the first support pin 18 corresponding to between the base 14 and the lifting / lowering base 15, the base 14 and the lifting / lowering base 15 are compacted, and Between the first compression spring 20 whose base end (lower end) is fixed to the base 14 side, and between the upper surface of the large diameter portion 19a and the upper surface of the base 14 corresponding to the middle of the second support pin 19 in the axial direction. A flange-shaped stopper 21 is provided on the outer periphery of the corresponding small diameter portion 19b so as to be slidable in the axial direction (vertical direction) thereof, and comes into contact with the upper surface of the elevating and lowering table 15 and moves up and down together with the elevating and moving table 15.
And the upper surface of the stopper 21 and the first molding die 11 in a state of being wound around the small diameter portion 19b of the second support pin 19.
The second compression spring 22 which is compressed between the lower surface of the second compression spring and the stopper 21 and each end of which is fixed to the first molding die 11.
It has and. The elevating and moving base 15 is adapted to be lifted after the lower mold 3 is opened by an ejector pin (not shown). In this case, the first and second support pins 1
Reference numerals 8 and 19 are included in the components of the first molding die 11 that move up and down integrally with the up and down movement of the first molding die 11. On the other hand, the up-and-down moving table 15, the penetrating pin 16, and the contact pin 17 are included in the components of the second molding die 12 that integrally move up and down as the second molding die 12 moves up and down.

Further, as shown in FIG. 3, when the upper mold 2 and the lower mold 3 are closed, the first compression spring 20 is contracted to the compression limit position, and the stopper 21 is closed by the second compression spring. It is located above the elevating and lowering table 15 where the biasing force of 22 does not act. The lower mold 3 is opened from this mold closed state, the base 14 is lowered when the lower mold 3 is lowered, and by the urging force of the first compression spring 20,
The first molding die 11 is regulated while restricting the lowering of the elevating and moving base 15.
By allowing the lower die 3 to descend through each of the columns 13, the first bumper B is held between the upper die 2 and the second molding die 12 when the lower die 3 is lowered in the mold opening direction. Only the forming die 11 can be lowered. Further, the stopper 21
Is the first molding die 11 (the small diameter portion 19 of the second support pin 19).
b) and the second molding die 12 (lifting / lowering table 15), which is provided when the lower die 3 (base 14) is lowered.
The preceding lowering of the molding die 11 is maintained at a position where the elevating and lowering table 15 starts to descend together with the first molding die 11, that is, the biasing force of the first compression spring 20 and the biasing force of the second compression spring 22 are kept in balance. The stopper 2 is provided on the upper surface of the lifting / lowering base 15.
1 is configured to be regulated at a position where it is lowered by a predetermined amount to hold it in a contact state. In this case, a gap X is formed between the first molding die 11 and the back surface Bb of the bumper B by the preceding lowering of the first molding die 11 in the mold opening direction until the restriction by the stopper 21 is performed. This gap X is formed in the first mold 11 when the second mold 12 descends in the mold opening direction together with the first mold 11 from the preceding lowering position of the first mold 11. It is set to such an extent that the corresponding portion of the corresponding bumper B can be peeled off from the upper mold 2 and allowed to escape to the first molding die 11 side.

Next, a procedure for taking out the bumper B from the injection molding die apparatus 1 will be described with reference to FIGS. 1 and 3 to 5.

First, as shown in FIG. 1, when the lower die 3 is lowered, the lifting movement table 15 (second molding die 12) is moved downward from the state of FIG. 3 by the urging force of the first compression spring 20. Without lowering the first molding die 11 in advance in the mold opening direction, and when the first molding die 11 descends by a predetermined amount, the stopper 21 causes the first molding die 11 to descend in the mold opening direction. regulate.

By restricting the preceding lowering of the first molding die 11 by the stopper 21, the elevating and moving base 15 can be lowered together with the first molding die 11 via the stopper 21. At this time, the first mold 11 and the bumper B
A predetermined amount of the gap X is formed between the back surface Bb of the first molding die 11 and the back surface Bb of the first molding die 11, and the first molding die 11 and the second molding die 12 are separated from each other as shown in FIG. When descending in the mold opening direction via the elevating / moving base 15, the corresponding portion of the bumper B corresponding to the first molding die 11 is peeled off from the upper mold 2 to allow the inside of the gap X to escape to the first molding die 11 side. The first molding die and the second molding die 12 can be smoothly lowered in the mold opening direction via the ascending / descending movement table 15. Then, as shown in FIG. 5, the second compression spring 2
The second moving mold 12 is moved upward with respect to the first forming mold 11 by moving the lifting / lowering moving table 15 upward with ejector pins while compressing the second mold 2, and the bumper B is removed from the second forming mold 12.

Therefore, in the above embodiment, the stopper 2
1, the bumper B is moved to the upper mold 2 and the second mold when the lower mold 3 is opened.
The second molding die 1 in a state of being held between the molding die 12 and the second molding die 1.
2, the first molding die 11 is lowered in advance in the mold opening direction, and when the descending amount of the first molding die 11 reaches a predetermined amount, the preceding movement of the first molding die 11 is restricted. Therefore, the preceding movement of the first molding die 11 in the mold opening direction forms the gap X between the first molding die 11 and the back surface Bb of the bumper B. Therefore, the first and second molding dies 11 from the state where the gap X is formed,
When the mold 12 is opened, the corresponding part of the bumper B corresponding to the first mold 11 is peeled off from the upper mold 2 and escapes in the gap X toward the first mold 11 so that the surface Ba is not rubbed against the upper mold 2. In addition, it is possible to prevent the surface Ba of the bumper B from being scratched and to smoothly open the mold.

Moreover, in order to prevent the surface Ba from being scratched, it is not necessary to set the die-cutting angle α with respect to the upper die 2 to 10 ° or more, and the degree of freedom in designing the bumper B can be expanded.

The present invention is not limited to the above embodiment, but includes various other modifications.
For example, in the above embodiment, the lower mold 3 is divided into the first molding mold 11 and the second molding mold 12 with the mold cutting angles α and β with respect to the upper mold 2 as a boundary, but resin molding such as bumper is performed. Depending on the shape of the product, it may be divided into a first molding die and a second molding die at a boundary of 10 ° or more or less than 10 °, in which case a resin molded product can be easily formed without scratching the surface. Can be taken out.

In the above embodiment, the stopper 21 stops the first mold 11 from descending a predetermined amount in the preceding mold opening direction, and then the first mold 11 is moved to the second mold 12.
However, it is also possible to open only the upper mold upward with respect to the lower mold at the position where the first mold has stopped descending in the preceding mold opening direction.

Further, although the bumper B is applied as the resin molded product in the above embodiment, any plate-shaped resin molded product may be used.

[0022]

As described above, according to the injection molding die apparatus of the first aspect of the invention, the first molding die moves in the preceding mold opening direction when the back molding die is opened.
The corresponding portion of the resin molded product corresponding to the molding die can be released to the first molding die side to eliminate rubbing against the surface molding die, and the resin molded product can be easily taken out while preventing damage to the surface corresponding portion. Thus, it is possible to increase the degree of freedom in designing a resin molded product that does not require a die-cutting angle of a predetermined value or more.

According to the injection molding die apparatus of the second aspect of the present invention, the back surface molding die is divided into the first molding die and the second molding die with a die cutting angle of 10 ° as a boundary. Even if the angle is less than 10 °, it is possible to effectively prevent the surface of the resin molded product from being scratched, and to expand the degree of freedom in designing the resin molded product without being restricted by the die-cutting angle.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view showing a state in which a first molding die of an injection molding die device according to an exemplary embodiment of the present invention is moved in the mold opening direction in advance.

FIG. 2 is an enlarged sectional view of a gap portion according to FIG.

FIG. 3 is a vertical sectional front view showing a mold closed state of the injection molding die device.

FIG. 4 is a vertical sectional front view showing a mold opening completion state of the injection molding die device.

FIG. 5 is a vertical cross-sectional front view showing a bumper take-out state of the injection molding die device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Mold device for injection molding 2 Upper mold (front surface molding mold) 3 Lower mold (back surface molding mold) 4 Cavity 11 First molding mold 12 Second molding mold 21 Stopper α Die cutting angle of less than 10 ° (less than a predetermined value) Die cut angle β β Die cut angle of 10 ° or more (Die cut angle of a predetermined value or more) B Bumper (resin molded product) Ba Bumper surface Bb Bumper back surface

Claims (2)

[Claims] 1. A plate-shaped resin molding by injecting a resin raw material into a cavity formed by a front surface molding die for molding a front surface side of a molded article and a back surface molding die for molding a rear surface side of the molded article. An injection molding die device for molding a product, wherein the back surface molding die has a first molding die whose die-cutting angle with respect to the front surface molding die is less than a predetermined value when the die is opened, and The surface molding die is divided into a second molding die having a die-cutting angle of a predetermined value or more, and the resin molding is surfaced between the first molding die and the second molding die when the mold is opened. Allowing the first mold to move in the mold opening direction with respect to the second mold in a state of being held between the mold and the second mold, and the movement amount of the first mold becomes a predetermined amount. A stopper for restricting the movement of the first molding die when That the injection molding die apparatus. 2. The injection molding die according to claim 1, wherein the back surface molding die is divided into a first molding die and a second molding die at a boundary of 10 ° with respect to the front surface molding die. Mold device.