JP2905413B2 - Injection mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mold for injection molding.

[0002]

2. Description of the Related Art Conventionally, an injection molding machine has an injection mold composed of a fixed mold and a movable mold, and the movable mold is brought into contact with the fixed mold by closing the mold with a mold clamping device. A cavity is formed between the two.
Then, the mold is clamped, and the melted resin is filled in the cavity, and the resin is cooled to form a molded product. After that, mold opening is performed,
The molded product is released from the mold by the ejector device.

[0003] In an injection molding machine for molding an optical disk substrate, an air blow device is used as an ejector device, and compressed air is ejected from a fixed mold and a movable mold at the time of releasing the mold. The optical disc substrate is separated from the fixed mold and the movable mold by the injection pressure. 2 is a cross-sectional view of a conventional injection mold, FIG. 3 is a cross-sectional view taken along line AA of FIG. 4, and FIG. 4 is a cross-sectional view of a main part of the conventional injection mold.

In FIG. 1, reference numeral 11 denotes a fixed die, and 12 denotes a movable die which is disposed so as to be able to contact and separate from the fixed die 11 so as to be freely movable. The fixed mold 11 includes a fixed block 13 and a fixed mold plate 14 attached to the fixed block 13.
And a cylindrical fixed-side air blow bush 15 penetrates the center of the fixed-side block 13 and the fixed-side mold plate 14. A die 16 for forming a hole in a molded product is slidably disposed in the fixed-side air blow bush 15.

On the other hand, the movable mold 12 is
9 and a movable mold plate 20 attached to the movable block 19, and a central portion of the movable block 19 and the movable mold plate 20 is formed in a cylindrical movable air blow bush 21.
Penetrates. In the movable air blow bush 21, a punch 22 for punching a molded product is slidably provided.

In the injection mold having the above-described structure, the movable mold 1 is closed by a mold clamping device (not shown).
When 2 is brought into contact with the fixed mold 11, a cavity is formed between the fixed mold plate 14 and the movable mold plate 20. Then, the mold is clamped by the mold clamping device, and while the movable mold plate 20 is pressed against the fixed mold plate 14, the cavity is filled with the melted resin and cooled. It becomes the optical disk substrate 24.

Next, the punch 22 is advanced toward the fixed mold 11 and the die 16 is retracted, whereby a punching process is performed on the optical disc substrate 24 to form a punch hole 25. Subsequently, the mold is opened by the mold clamping device, and the movable mold 12 is retracted. At this time, compressed air is injected to release the optical disc substrate 24 from the fixed mold plate 14 and the movable mold plate 20, and a jet pressure is applied to the optical disc substrate 24.

For this purpose, an air supply path 31 is formed in the fixed block 13. The air supply passage 31 has one end open to the side surface of the fixed block 13 and the other end open to the fixed air blow bush 15, and supplies compressed air sent from a compressed air supply source (not shown) to the fixed air blow bush 1.
5 is supplied to an air flow path 32 formed around the periphery of the fuel cell 5. The compressed air supplied to the air flow path 32 passes through the air flow path 32 and spreads in the entire circumferential direction of the fixed-side air blow bush 15, and the end face (the lower end in the figure) of the fixed-side air blow bush 15 The liquid is injected toward the optical disc substrate 24 from an annular slit 34 formed between the fixed side mold plate 14 and the end face.

The fixed air blow bush 15 is fixed to the fixed air blow bush 15 so that the compressed air in the air flow path 32 does not escape through a gap (gap) between the fixed block 13 and the fixed air blow bush 15. An O-ring 35 is provided between the O-ring 35 and the block 13. Also, the fixed block 1 is fixed so that the compressed air in the air flow path 32 does not escape through the gap between the fixed block 13 and the fixed mold plate 14.
An O-ring 36 is provided between the third mold plate 3 and the fixed mold plate 14.

On the other hand, an air supply path 41 is formed in the movable block 19. One end of the air supply passage 41 is opened on the side surface of the movable side block 19 and the other end is opened facing the movable side air blow bush 21. The compressed air sent from a compressed air supply source (not shown) is provided around the movable side air blow bush 21. The air is supplied to the air flow path 43 formed at the bottom. The air passage 4
The compressed air supplied to the movable air blow bush 3 passes through the air flow path 43 and spreads in the entire circumferential direction of the movable air blow bush 21, and the end face (the upper end in the figure) of the movable air blow bush 21 and the movable mold plate The liquid is injected toward the optical disc substrate 24 from an annular slit 44 formed between the end face of the optical disc 20 and the end face 20.

The movable air blow bush 21 and the movable block 19 are connected to each other so that the compressed air in the air flow path 43 does not escape through the gap between the movable block 19 and the movable air blow bush 21. O-ring 4 between
5 are provided. Also, between the movable side mold plate 20 and the movable side block 19, the compressed air in the air flow path 43 is prevented from escaping through the gap between the movable side block 19 and the movable side mold plate 20. An O-ring 46 is provided.

The air passage 32 and the air passage 43 are formed vertically symmetrically with respect to the parting line surface between the fixed mold 11 and the movable mold 12, and have substantially the same structure. Therefore, the air flow path 43 will be described in detail with reference to FIGS. The annular slit 44 is formed between the outer peripheral surface of the movable-side air blow bush 21 and the inner peripheral surface of the movable-side mold plate 20. δ is set to be substantially “0”. Therefore, the air passage 43 is formed of a groove pattern formed on the outer peripheral surface of the movable air blow bush 21.

That is, the air passage 43 has a first annular groove 51 formed adjacent to the air supply passage 41 and a second annular groove 5 formed adjacent to the annular slit 44.
2, and a plurality of axial grooves 53 to 5 formed by connecting the first annular groove 51 and the second annular groove 52 to each other.
Consists of six. In this embodiment, the axial grooves 53 to 56 are provided at four positions in the circumferential direction of the movable air blow bush 21.

The first annular groove 51, the second annular groove 52, and the axial grooves 53 to 56 are all formed by cutting the surface of the movable air blow bush 21 by a predetermined thickness. The movable block 19 and the movable mold plate 20 are respectively closed to form a flow path structure. Therefore, the compressed air supplied to the air flow path 43 via the air supply path 41 first reaches the first annular groove 51, spreads in the first annular groove 51 in the circumferential direction, and The second annular groove 52 is reached via the grooves 53 to 56. Then, the inside of the second annular groove 52 expands in the circumferential direction, and is jetted from the annular slit 44.

[0015]

However, in the conventional injection mold, the compressed air supplied from the air supply passage 41 to the air flow passage 43 flows in the first annular groove 51 in the circumferential direction. After it spreads, it reaches the second annular groove 52 via the axial grooves 53 to 56,
The timing at which the compressed air reaches the axial grooves 53 and 55 is different from the timing at which the compressed air reaches the axial grooves 54 and 56, and the pressure of the compressed air reaching the axial grooves 53 and 55 and the axial The pressure of the compressed air reaching the grooves 54, 56 will also be different.

In this case, even when the compressed air is injected from the annular slit 44, the injection timing and pressure are different at the circumferential position of the annular slit 44. As a result, the release of the optical disk substrate 24 cannot be performed smoothly, or the optical disk substrate 24 cannot be released.
May be deformed.

The present invention solves the above-mentioned problems of the conventional injection mold, makes it possible to smoothly release the molded product, and does not deform the molded product at the time of release. An object of the present invention is to provide a molding die.

[0018]

For this purpose, in the injection molding die of the present invention, a fixed die, a movable die which is disposed so as to be able to freely contact and separate from the fixed die, and An air blow bush is provided so as to penetrate at least one of the fixed mold and the movable mold and face the end face to the cavity.

An air passage for supplying compressed air supplied from a compressed air supply source to an annular slit formed facing the cavity is formed on the outer peripheral surface of the air blow bush. The air flow path includes a first annular groove communicating with the compressed air supply source, a second annular groove formed adjacent to the annular slit, and a first annular groove in the axial direction of the air blow bush. A third annular groove formed between the second annular groove and two first axial grooves formed by connecting the first annular groove and the third annular groove to each other; It has a plurality of second axial grooves formed between the third annular groove and the second annular groove so as to communicate with each other.

The first axial groove is formed at a portion of the first annular groove which is distributed 90 degrees to the left and right from the communicating portion with the compressed air supply source. In another injection molding die of the present invention, the distance between the first axial groove and the second axial groove in the circumferential direction of the air blow bush is made equal to each other.

[0021]

According to the present invention, as described above, in the injection molding die, a fixed die, a movable die which is disposed so as to be opposed to and separated from the fixed die, and An air blow bush disposed so as to penetrate at least one of the mold and the movable mold and face the end surface to the cavity.

Accordingly, the mold can be closed, clamped and opened by moving the movable mold toward and away from the fixed mold. After the mold is opened, the molded product is released by air blow. For this purpose, an air flow path for supplying compressed air supplied from a compressed air supply source to an annular slit formed facing the cavity is formed on the outer peripheral surface of the air blow bush.

The air flow path includes a first annular groove communicating with the compressed air supply source, a second annular groove formed adjacent to the annular slit, and a first annular groove in the axial direction of the air blow bush. A third annular groove formed between the annular groove and the second annular groove, and two first axial grooves formed by communicating the two between the first annular groove and the third annular groove. And a plurality of second axial grooves formed between the third annular groove and the second annular groove so as to communicate with each other.

The first axial groove is formed in a portion of the first annular groove which is distributed 90 degrees to the left and right from the communicating portion with the compressed air supply source. In this case, the compressed air from the compressed air supply source first reaches the first annular groove, spreads in the first annular groove in the circumferential direction, and then enters the third annular groove via the first axial groove. To reach. In this case, since the first axial grooves are located in the circumferential direction of the first annular groove at portions separated 90 degrees to the left and right from the communicating portion to the compressed air supply source, and have the same cross-sectional area as each other. The timing at which the compressed air reaches each of the first axial grooves becomes equal.

In another injection mold of the present invention,
The distance between each first axial groove and the second axial groove in the circumferential direction of the air blow bush is made equal to each other. In this case, the compressed air that has reached the third annular groove expands in the third annular groove in the circumferential direction and reaches the second annular groove via the second axial groove. The distance between the second axial groove and the first axial groove in the direction is equal. Therefore, the timing at which the compressed air reaches each of the second axial grooves becomes equal to each other.

[0026]

Embodiments of the present invention will be described below in detail with reference to the drawings. 1 is a sectional view of a main part of an injection mold according to an embodiment of the present invention, FIG. 5 is a sectional view taken along line XX of FIG. 1, and FIG. 6 is a sectional view taken along line YY of FIG. Since the structure other than the air flow path is substantially the same as that of the conventional technology, the description thereof will be omitted with reference to FIG. Although only the movable mold is described, the fixed mold has a similar air flow path structure.

In the figure, reference numeral 19 denotes a movable block,
Is a movable side mold plate attached to the movable side block 19. A tubular movable air blow bush 61 penetrates through the center of the movable block 19 and the movable mold plate 20. In the movable air blow bush 61, a punch 22 for punching a molded product is slidably disposed.

An air supply path 41 for air blow is formed in the movable block 19. The air supply passage 41 has one end open to the side surface of the movable block 19 and the other end facing the movable air blow bush 61. The compressed air supplied from a compressed air supply source (not shown) is Is supplied to the air flow path 63 formed at the bottom. The compressed air supplied to the air passage 63 passes through the air passage 63 and spreads in the entire circumferential direction of the movable-side air blow bush 61, and the compressed air supplied to the end surface (the upper end in the figure) of the movable-side air blow bush 61. The liquid is injected toward the optical disc substrate 24 from an annular slit 64 formed between the movable side mold plate 20 and the end face.

The movable air blow bush 61 and the movable block 19 are connected to each other so that the compressed air in the air flow passage 63 does not escape through the gap between the movable block 19 and the movable air blow bush 61. O-ring 6 between
5 are provided. Also, between the movable side mold plate 20 and the movable side block 19, the compressed air in the air flow path 63 is prevented from escaping through the gap between the movable side block 19 and the movable side mold plate 20. An O-ring 66 is provided.

Next, the air passage 63 will be described in detail. In this case, the annular slit 64 is formed between the outer peripheral surface of the movable-side air blow bush 61 and the inner peripheral surface of the movable-side mold plate 20. The clearance δ of 64 is set to be substantially “0”. Therefore, the air passage 63 is formed of a groove pattern formed on the outer peripheral surface of the movable air blow bush 61.

That is, the air flow passage 63 has a first annular groove 71 formed adjacent to the air supply passage 41 and a second annular groove 7 formed adjacent to the annular slit 64.
2, and a third annular groove 81 formed between the first annular groove 71 and the second annular groove 72 in the axial direction of the movable-side air blow bush 61. Further, the air passage 63 is
Two first axial grooves 82 and 83 formed by connecting the first annular groove 71 and the third annular groove 81 to each other, and the third annular groove 81 and the second annular groove 72 A plurality of second axial grooves 73 to 76 formed by allowing the two to communicate with each other.
Consists of In the present embodiment, the second axial grooves 73 to 76 are provided at four locations in the circumferential direction of the movable air blow bush 61, and have the same sectional area.

The first annular groove 71, the second annular groove 72, the third annular groove 81, the first axial grooves 82 and 83, and the second axial grooves 73 to 76 are all movable movable air blow bushes 61. Are cut by a predetermined thickness, and are closed by a movable block 19 and a movable mold plate 20 arranged opposite to each other to form a flow path structure.

The first axial grooves 82 and 83 are formed in the circumferential direction of the movable-side air blow bush 61 at portions that are distributed 90 degrees to the left and right from the communication portion P1 with the air supply passage 41, and each of the first axial grooves 82 and 83 is formed. The areas are made equal to each other. Therefore, the compressed air supplied to the air flow path 63 via the air supply path 41 first reaches the first annular groove 71 and spreads in the first annular groove 71 in the circumferential direction, and The third annular groove 81 is reached via the axial grooves 82 and 83. In this case, the first axial grooves 82 and 83 are located in the circumferential direction of the movable-side air blow bush 61 at portions separated 90 degrees to the left and right from the communication portion P1 with the air supply passage 41, and are separated from each other. The areas are equal. Therefore, the timing at which the compressed air reaches the first axial grooves 82 and 83 becomes equal.

Subsequently, the compressed air that has reached the third annular groove 81 spreads in the third annular groove 81 in the circumferential direction, and is transmitted to the second annular groove 72 via the second axial grooves 73 to 76. To reach. In this case, the second axial grooves 73 and 74 and the first axial groove 82 in the circumferential direction of the movable air blow bush 61 are provided.
And the distance between the second axial grooves 75 and 76 and the first axial groove 83 is also equal. Therefore, each second
The timing at which the compressed air reaches the axial grooves 73 to 76 becomes equal to each other.

As a result, in the compressed air injected from the annular slit 64, the injection timing and pressure are equal at the circumferential position of the annular slit 64, so that the optical disk substrate 24 can be released smoothly. It is also possible to prevent the optical disc substrate 24 from being deformed. It should be noted that the present invention is not limited to the above-described embodiments, but can be variously modified based on the gist of the present invention, and they are not excluded from the scope of the present invention.

[0036]

As described above in detail, according to the present invention, in a mold for injection molding, a fixed mold and a movable mold which is disposed so as to be able to freely contact and separate from the fixed mold. A mold and at least one of the fixed mold and the movable mold is penetrated,
And an air blow bush disposed with the end face facing the cavity.

After the mold is opened, compressed air supplied from a compressed air supply source is exposed to the cavity on the outer peripheral surface of the air blow bush in order to release the molded product by air blow. An air flow path for supplying the formed annular slit is formed. A first annular groove communicating with the compressed air supply source; a second annular groove formed adjacent to the annular slit;
A third annular groove formed between a first annular groove and a second annular groove in the axial direction of the air blow bush;
Two first axial grooves formed by communicating the two between the annular groove and the third annular groove, and formed by communicating the two between the third annular groove and the second annular groove. And a plurality of second axial grooves.

The first axial groove extends 90 degrees from the communicating portion to the compressed air supply source in the first annular groove.
It is formed in each of the divided parts. In this case, since the first axial grooves are located in the circumferential direction of the first annular groove at portions separated 90 degrees to the left and right from the communicating portion to the compressed air supply source, and have the same cross-sectional area as each other. The timing at which the compressed air reaches each of the first axial grooves becomes equal.

Therefore, in the compressed air injected from the annular slit, the injection timing and pressure are equal at the circumferential position of the annular slit, so that the molded product can be smoothly released from the mold. Can be prevented from being deformed. In another injection molding die of the present invention, the distance between the first axial groove and the second axial groove in the circumferential direction of the air blow bush is made equal to each other.

In this case, the compressed air that has reached the third annular groove spreads in the third annular groove in the circumferential direction and reaches the second annular groove via the second axial groove. The distance between the second axial groove and the first axial groove in the circumferential direction is equal. Therefore, the timing at which the compressed air reaches each of the second axial grooves becomes equal to each other. Therefore, in the compressed air injected from the annular slit, the injection timing and pressure are equal at the circumferential position of the annular slit, so that the molded product can be released smoothly, and the molded product is deformed. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of an injection mold according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a conventional injection mold.

FIG. 3 is a sectional view taken along line AA of FIG. 4;

FIG. 4 is a cross-sectional view of a main part of a conventional injection mold.

FIG. 5 is a sectional view taken along line XX of FIG. 1;

FIG. 6 is a sectional view taken along line YY of FIG. 1;

[Explanation of symbols]

 61 Movable air blow bush 63 Air flow path 64 Annular slit 71 First annular groove 72 Second annular groove 73-76 Second axial groove 81 Third annular groove 82, 83 First axial groove

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-2-215512 (JP, A) JP-A-6-31782 (JP, A) JP-A-5-314546 (JP, A) JP-A-1- 200924 (JP, A) JP-A-6-3620 (JP, A) JP-A-7-137097 (JP, A) JP-A-7-9510 (JP, A) JP-A-5-16265 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) B29C 45/43, 33/46

Claims (2)

(57) [Claims] 1. A fixed mold, (b) a movable mold that is disposed so as to be able to contact and separate from the fixed mold, and (c) at least one of the fixed mold and the movable mold. Let one penetrate,
An air blow bush disposed with the end face facing the cavity, and (d) formed on the outer peripheral surface of the air blow bush with compressed air supplied from a compressed air supply source facing the cavity. (E) the air flow path to be supplied to the annular slit is formed.
A first annular groove communicating with the compressed air supply source, a second annular groove formed adjacent to the annular slit, and a first annular groove and a second annular groove in the axial direction of the air blow bush. A third annular groove formed, two first axial grooves formed by connecting the first annular groove and the third annular groove to each other, the third annular groove, and the second annular groove; And a plurality of second axial grooves formed by communicating the two with the groove. (F) The first axial groove communicates with a compressed air supply source in the first annular groove. A mold for injection molding, wherein the mold is formed at a portion divided 90 degrees from the left and right sides. 2. The injection mold according to claim 1, wherein the distance between each of the first axial groove and the second axial groove in the circumferential direction of the air blow bush is equal to each other.